Surgical techniques

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[[Category:Patient safety]] [[Category:Venous access]] [[Category:Infection]] [[Category:Universal precautions]] [[Category:Equipment]] [[Category:Positioning patients]] [[Category:Endoscopy]] [[Category:Incisions]] [[Category:Tissue dissection]] [[Category:Haemostasis]] [[Category:Surgical instruments]] [[Category:Drains]] [[Category:Suturing]]
 
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<div class="chapter" title="Surgical techniques">
<div class="chapter" title="Surgical techniques">
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== Introduction ==
 
-
This chapter reviews techniques used in surgical practice and invasive procedures.
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==Introduction==
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== The operating room mates ==
+
This chapter reviews techniques used in surgical practice and invasive procedures.
-
The operating room is a dedicated area for surgical procedures and must be conducive to performing surgery to the highest standards of safety for patients and staff. The principal purpose of such a dedicated area is to reduce the risk of infection of patients. The operating room must be large enough for complex procedures to be undertaken, for storage of appropriate equipment, movement of staff, as well as the maintenance of a sterile area around the operative field. By changing the operating room air 20–25 times each hour at positive pressure relative to outside the room, low concentrations of airborne bacteria and particulate matter can be maintained. The number of people in the room and their movement should be minimised. Ambience should be calm and professional, and the air temperature such that inadvertent patient hypothermia does not occur. The operative field must be well illuminated by direct bright light, and surgeons sometimes wear a head light for procedures in body cavities which cannot be illuminated easily by standard operating room lights.
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==The operating room==
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The surgeon's assistant has the important role of assisting and supporting the surgeon in the smooth conduct of operations. It is important to concentrate on the task at hand, to carry out the surgeon's instructions with speed and accuracy, to have a sense of anticipation, and to notify the surgeon of any potential hazard during the operation.  
+
The operating room is a dedicated area for surgical procedures and must be conducive to performing surgery to the highest standards of safety for patients and staff. The principal purpose of such a dedicated area is to reduce the risk of infection of patients. The operating room must be large enough for complex procedures to be undertaken, for storage of appropriate equipment, movement of staff, as well as the maintenance of a sterile area around the operative field. By changing the operating room air 20–25 times each hour at positive pressure relative to outside the room, low concentrations of airborne bacteria and particulate matter can be maintained. The number of people in the room and their movement should be minimised. Ambience should be calm and professional, and the air temperature such that inadvertent patient hypothermia does not occur. The operative field must be well illuminated by direct bright light, and surgeons sometimes wear a head light for procedures in body cavities which cannot be illuminated easily by standard operating room lights.
-
A face mask which covers the nose and mouth prevents droplet spread of bacteria, is worn for any invasive procedure and is changed after each case. Eye protection in the form of plain plastic glasses or a visor attached to the face mask must be worn to protect against droplet spray of infected body fluids. Gloves are worn if there is a possibility of coming into contact with patients' body fluids. Clean theatre attire, dedicated theatre shoes, and a disposable hair cover are worn while in the operating suite.  
+
The surgeon's assistant has the important role of assisting and supporting the surgeon in the smooth conduct of operations. It is important to concentrate on the task at hand, to carry out the surgeon's instructions with speed and accuracy, to have a sense of anticipation, and to notify the surgeon of any potential hazard during the operation.
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=== Aseptic techniques ===
+
A face mask which covers the nose and mouth prevents droplet spread of bacteria, is worn for any invasive procedure and is changed after each case. Eye protection in the form of plain plastic glasses or a visor attached to the face mask must be worn to protect against droplet spray of infected body fluids. Gloves are worn if there is a possibility of coming into contact with patients' body fluids. Clean theatre attire, dedicated theatre shoes, and a disposable hair cover are worn while in the operating suite.
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Aseptic techniques are clinical practices which aim to prevent infection occuring in the patient as a result of the surgical procedure by:
+
===Aseptic techniques===
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*Preparation and cleaning the patient's skin with antiseptic fluid before it is cut or punctured.
+
Aseptic techniques are clinical practices which aim to prevent infection occuring in the patient as a result of the surgical procedure by:
-
*Use of sterilised instruments, equipment or surgical materials which might come into contact with the operative field and surgical wound.
+
-
Personnel involved directly in the operative procedure (surgeon, surgical assistant and ‘scrub’ nurse) wash their hands and forearms with antiseptic soap for 5 minutes before the first operation of the day and for 3 minutes before each subsequent case to reduce skin flora. Hands are dried with sterile towels, and a moisture-impermeable sterile gown is worn. One or two pairs of sterile gloves prevent transfer of bacteria from the surgeon's hands to the patient and also protect the surgeon from infected blood and body fluids from the patient.  
+
* Preparation and cleaning the patient's skin with antiseptic fluid before it is cut or punctured.
 +
* Use of sterilised instruments, equipment or surgical materials which might come into contact with the operative field and surgical wound.
-
The patient should shower or bathe with an antiseptic soap before going to the operating room. After induction of anaesthesia, hair is removed from the operative site by shaving with a razor or electric clippers. The skin is cleansed with an antiseptic solution starting at the site where the incision will be made and working away from the area, so that approximately 10–20 cm of skin around the incision site is prepared. The patient is covered with sterile linen or impermeable drapes, leaving exposed only the cleansed area around the incision site, which may be covered by a sterile adhesive plastic drape.  
+
Personnel involved directly in the operative procedure (surgeon, surgical assistant and ‘scrub’ nurse) wash their hands and forearms with antiseptic soap for 5 minutes before the first operation of the day and for 3 minutes before each subsequent case to reduce skin flora. Hands are dried with sterile towels, and a moisture-impermeable sterile gown is worn. One or two pairs of sterile gloves prevent transfer of bacteria from the surgeon's hands to the patient and also protect the surgeon from infected blood and body fluids from the patient.
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=== Surgical antiseptics ===
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The patient should shower or bathe with an antiseptic soap before going to the operating room. After induction of anaesthesia, hair is removed from the operative site by shaving with a razor or electric clippers. The skin is cleansed with an antiseptic solution starting at the site where the incision will be made and working away from the area, so that approximately 10–20 cm of skin around the incision site is prepared. The patient is covered with sterile linen or impermeable drapes, leaving exposed only the cleansed area around the incision site, which may be covered by a sterile adhesive plastic drape.
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The commonest source of bacterial contamination in the operating room is from the patient. Therefore, topical antiseptic agents are used to reduce the number of skin organisms prior to any skin incision or puncture, and include:
+
===Surgical antiseptics===
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*Aqueous chlorhexidine (0.5%) is used to disinfect mucous membranes and parts of the body adjacent to structures which would be adversely affected by more stringent antiseptics (e.g. the skin around the eyes). Aqueous chlorhexidine is bactericidal and has low tissue toxicity.
+
The commonest source of bacterial contamination in the operating room is from the patient. Therefore, topical antiseptic agents are used to reduce the number of skin organisms prior to any skin incision or puncture, and include:
-
*Cetrimide (2%) is bactericidal.
+
-
*Iodine-based antiseptics (e.g. povidone iodine (10%) [Betadine], alcoholic iodine solution) destroy a wide range of bacteria, especially staphylococci, by iodisation of microbial proteins.
+
-
*Alcohol-based (70%) antiseptics kill bacteria by evaporation.
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=== Sterility ===
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* Aqueous chlorhexidine (0.5%) is used to disinfect mucous membranes and parts of the body adjacent to structures which would be adversely affected by more stringent antiseptics (e.g. the skin around the eyes). Aqueous chlorhexidine is bactericidal and has low tissue toxicity.
 +
* Cetrimide (2%) is bactericidal.
 +
* Iodine-based antiseptics (e.g. povidone iodine (10%) [Betadine], alcoholic iodine solution) destroy a wide range of bacteria, especially staphylococci, by iodisation of microbial proteins.
 +
* Alcohol-based (70%) antiseptics kill bacteria by evaporation.
 +
 
 +
===Sterility===
 +
 
 +
Anything that comes into contact with the surgical wound must be sterile. The method of sterilisation depends on the item being sterilised ([[Surgical%20techniques#ch4-box1|Methods of sterilisation]]).
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Anything that comes into contact with the surgical wound must be sterile. The method of sterilisation depends on the item being sterilised ([[Surgical techniques#ch4-box1|Methods of sterilisation]]).
 
<div id="ch4-box1" class="sidebar"><div class="title">
<div id="ch4-box1" class="sidebar"><div class="title">
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'''Methods of sterilisation'''
 
-
</div>
 
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'''Autoclave'''
 
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Uses superheated steam at high pressure to reach a temperature of 121 degrees. Sterilisation is achieved when droplets of superheated water evaporate immediately upon reduction of pressure, thus destroying micro-organisms and leaving instruments dry. Most surgical instruments and linen drapes are sterilised by autoclaving.  
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'''Methods of sterilisation'''
 +
 
 +
</div>
 +
 
 +
'''Autoclave'''
 +
 
 +
Uses superheated steam at high pressure to reach a temperature of 121 degrees. Sterilisation is achieved when droplets of superheated water evaporate immediately upon reduction of pressure, thus destroying micro-organisms and leaving instruments dry. Most surgical instruments and linen drapes are sterilised by autoclaving.
 +
 
 +
'''Dry heat'''
 +
 
 +
Items which tolerate heat but not moisture can be sterilised by dry heat, but it is less efficient and takes longer than autoclaving.
 +
 
 +
'''Ethylene oxide gas'''
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'''Dry heat'''
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Takes several hours and is used for heat-sensitive items such as endoscopes, electrical and optical equipment and some plastics.
-
Items which tolerate heat but not moisture can be sterilised by dry heat, but it is less efficient and takes longer than autoclaving.
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'''Glutaraldehyde'''
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'''Ethylene oxide gas'''
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A 2% solution is used to sterilise equipment which can tolerate moisture but not heat, such as urological catheters, plastics and rubber.
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Takes several hours and is used for heat-sensitive items such as endoscopes, electrical and optical equipment and some plastics.
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'''Ionising radiation'''
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'''Glutaraldehyde'''
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Uses gamma rays and is particularly useful for sterilising single-use disposables such as plastics, dressings, scalpel blades and synthetic conduits.
-
A 2% solution is used to sterilise equipment which can tolerate moisture but not heat, such as urological catheters, plastics and rubber.
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</div>
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'''Ionising radiation'''
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===Universal precautions===
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Uses gamma rays and is particularly useful for sterilising single-use disposables such as plastics, dressings, scalpel blades and synthetic conduits.  
+
The risk of transmission of infectious agents from patients to staff (and ''vice versa'') is reduced by practising universal precautions. Thus, it is assumed that all patients harbour potentially dangerous pathogens (e.g. hepatitis C, HIV) no matter how innocuous they appear, because carrier status cannot definitely be excluded without repeated, expensive and time consuming investigations. The principle of universal precautions is to establish a physical barrier between the patient and the carer to prevent direct contact with any potentially infected body fluid or tissue in either direction ([[Surgical%20techniques#ch4-box2|Universal precautions]]).
-
</div>
+
-
=== Universal precautions ===
+
-
The risk of transmission of infectious agents from patients to staff (and ''vice versa'') is reduced by practising universal precautions. Thus, it is assumed that all patients harbour potentially dangerous pathogens (e.g. hepatitis C, HIV) no matter how innocuous they appear, because carrier status cannot definitely be excluded without repeated, expensive and time consuming investigations. The principle of universal precautions is to establish a physical barrier between the patient and the carer to prevent direct contact with any potentially infected body fluid or tissue in either direction ([[Surgical techniques#ch4-box2|Universal precautions]]).
 
<div id="ch4-box2" class="sidebar"><div class="title">
<div id="ch4-box2" class="sidebar"><div class="title">
-
'''Universal precautions'''
 
-
</div>
 
-
'''Barrier protection'''
 
-
Appropriate protective barriers are used during invasive procedures and handling contaminated materials - gloves, face mask, eye shield, impermeable gown, shoe covers, hair cover.
+
'''Universal precautions'''
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'''Minimising potential exposure'''
+
</div>
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Decrease the risk of spreading potentially infected body fluids by avoiding spillages, careful disposal of materials and equipment contaminated by body fluids, having only essential personnel present during invasive procedures, excluding personnel with open wounds or abrasions, using impermeable dressings to cover wounds, using closed rather than open drains.
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'''Barrier protection'''
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'''Elimination of needle stick injuries'''
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Appropriate protective barriers are used during invasive procedures and handling contaminated materials - gloves, face mask, eye shield, impermeable gown, shoe covers, hair cover.
-
Do not handle uncapped needles, never re-sheath used needles, and never remove a used needle from a syringe. Use needles as little as possible. Immediately dispose of used needles in a designated ‘sharps’ disposal container which has a one-way opening.
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'''Minimising potential exposure'''
-
'''Elimination of other penetrating injuries'''
+
Decrease the risk of spreading potentially infected body fluids by avoiding spillages, careful disposal of materials and equipment contaminated by body fluids, having only essential personnel present during invasive procedures, excluding personnel with open wounds or abrasions, using impermeable dressings to cover wounds, using closed rather than open drains.
-
Sharp objects (e.g. scalpels, needles) are transferred between operating personnel in sharps dish, not from hand to hand. Hand-held needles are not used. Blunt suture needles are used where possible. Sharp instruments are not placed on the operative field or anywhere on the patient. Alert personnel to the presence of any sharp object in the operative field.
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'''Elimination of needle stick injuries'''
-
</div>
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-
=== Hazards ===
+
-
In addition to infection, there are many potential sources of hazard in the operating environment. Hazards, other than those intrinsic to the anaesthetic and surgical operation, are organisational, or related to operating room equipment or the transfer and positioning of the patient on the operating table.  
+
Do not handle uncapped needles, never re-sheath used needles, and never remove a used needle from a syringe. Use needles as little as possible. Immediately dispose of used needles in a designated ‘sharps’ disposal container which has a one-way opening.
-
==== Organisational hazards ====
+
'''Elimination of other penetrating injuries'''
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Organisational hazards should be entirely preventable. A full history and examination of the patient must be made before surgery, including the past medical history, drug history and allergies, so that elementary errors are not made (e.g. unwittingly operating on a patient with a pacemaker or who is anticoagulated, or prescribing a drug to which the patient is allergic). Before surgery commences, the reason for and nature of the operation, together with its potential common and serious complications, and the reasonable expectations from the procedure, are discussed with the patient and family who are free to ask any questions. A consent or request for treatment form, which states the nature of the operation and the side on which the operation is to be performed if the operation is a unilateral procedure, is signed by the patient and the surgeon or deputy.  
+
Sharp objects (e.g. scalpels, needles) are transferred between operating personnel in sharps dish, not from hand to hand. Hand-held needles are not used. Blunt suture needles are used where possible. Sharp instruments are not placed on the operative field or anywhere on the patient. Alert personnel to the presence of any sharp object in the operative field.
-
Once in the operating suite, a check is made that the patient is the correct one for that procedure, that the correct side or limb is identified and marked with an indelible pen, and that the lesion or lump is similarly marked to ensure that there is no confusion after the patient has been anaesthetised. All relevant case notes, investigation results and X-rays must be available in the operating room.
+
</div>
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==== Equipment ====
+
===Hazards===
-
Diathermy is used universally in surgical practice. High frequency alternating current passes from a small point of contact (active electrode) through the patient to a large contact site (indifferent electrode or diathermy plate) to produce localised heat which coagulates protein. Diathermy produces either (a) coagulation - haemostasis with a small amount of adjacent tissue damage, (b) cutting - tissue cutting with minimal tissue damage, or (c) fulgaration - haemostatsis with considerable tissue necrosis. Potential hazards include electrocution, inadvertent burn to the patient at a remote site and to the surgeon, fire associated with pooled alcohol-based antiseptics, explosion of flammable anaesthetic gases, and interference with the function of cardiac pacemakers.  
+
In addition to infection, there are many potential sources of hazard in the operating environment. Hazards, other than those intrinsic to the anaesthetic and surgical operation, are organisational, or related to operating room equipment or the transfer and positioning of the patient on the operating table.
-
A variety of lasers with different wavelengths and effects on cells and tissues are used in surgical practice for highly accurate tissue destruction (e.g. mucosal surgery, CNS tumours, dermatological lesions, aerodigestive tumours), coagulating blood vessels (e.g. gastrointestinal tract, retinal photocoagulation), and for photo-activation of intra-tumour haematoporphyrin for malignant tumour destruction (photodynamic therapy). Hazards include eye damage, explosion of anaesthetic gases, and shattering and destruction of other equipment.
+
====Organisational hazards====
-
Limb torniquets are used to provide a blood-less field in which to operate. The limb is elevated and exsanguinated by a rubber bandage or compressive sleeve, and the proximal torniquet inflated to 50 mm Hg (upper limb) or 100 mm Hg (lower limb) above systolic blood pressure. A torniquet should not be kept inflated for more than 60-90 minutes. Hazards include arterial thrombosis, distal ischaemia, nerve compression and skin traction.  
+
Organisational hazards should be entirely preventable. A full history and examination of the patient must be made before surgery, including the past medical history, drug history and allergies, so that elementary errors are not made (e.g. unwittingly operating on a patient with a pacemaker or who is anticoagulated, or prescribing a drug to which the patient is allergic). Before surgery commences, the reason for and nature of the operation, together with its potential common and serious complications, and the reasonable expectations from the procedure, are discussed with the patient and family who are free to ask any questions. A consent or request for treatment form, which states the nature of the operation and the side on which the operation is to be performed if the operation is a unilateral procedure, is signed by the patient and the surgeon or deputy.
-
==== Positioning of the patient ====
+
Once in the operating suite, a check is made that the patient is the correct one for that procedure, that the correct side or limb is identified and marked with an indelible pen, and that the lesion or lump is similarly marked to ensure that there is no confusion after the patient has been anaesthetised. All relevant case notes, investigation results and X-rays must be available in the operating room.
 +
 
 +
====Equipment====
 +
 
 +
Diathermy is used universally in surgical practice. High frequency alternating current passes from a small point of contact (active electrode) through the patient to a large contact site (indifferent electrode or diathermy plate) to produce localised heat which coagulates protein. Diathermy produces either (a) coagulation - haemostasis with a small amount of adjacent tissue damage, (b) cutting - tissue cutting with minimal tissue damage, or (c) fulgaration - haemostatsis with considerable tissue necrosis. Potential hazards include electrocution, inadvertent burn to the patient at a remote site and to the surgeon, fire associated with pooled alcohol-based antiseptics, explosion of flammable anaesthetic gases, and interference with the function of cardiac pacemakers.
 +
 
 +
A variety of lasers with different wavelengths and effects on cells and tissues are used in surgical practice for highly accurate tissue destruction (e.g. mucosal surgery, CNS tumours, dermatological lesions, aerodigestive tumours), coagulating blood vessels (e.g. gastrointestinal tract, retinal photocoagulation), and for photo-activation of intra-tumour haematoporphyrin for malignant tumour destruction (photodynamic therapy). Hazards include eye damage, explosion of anaesthetic gases, and shattering and destruction of other equipment.
 +
 
 +
Limb torniquets are used to provide a blood-less field in which to operate. The limb is elevated and exsanguinated by a rubber bandage or compressive sleeve, and the proximal torniquet inflated to 50 mm Hg (upper limb) or 100 mm Hg (lower limb) above systolic blood pressure. A torniquet should not be kept inflated for more than 60-90 minutes. Hazards include arterial thrombosis, distal ischaemia, nerve compression and skin traction.
 +
 
 +
====Positioning of the patient====
The patient is positioned on the operating table in such a way that the procedure is facilitated and the airway can be protected. Pressure points are padded, and limbs are positioned so that peripheral nerves, major blood vessels, joints and ligaments are not stretched or compressed. The anaesthetised patient must be in a stable position on the operating table and may need to be strapped on with broad adhesive tape. There must be no contact between the skin and any metallic surface because of the risk of diathermy burn and pressure necrosis. Sections of the operating table can be angled so that the patient is optimally positioned for the particular procedure (e.g. flexed while lying supine or on one side, head-down, head-up).
The patient is positioned on the operating table in such a way that the procedure is facilitated and the airway can be protected. Pressure points are padded, and limbs are positioned so that peripheral nerves, major blood vessels, joints and ligaments are not stretched or compressed. The anaesthetised patient must be in a stable position on the operating table and may need to be strapped on with broad adhesive tape. There must be no contact between the skin and any metallic surface because of the risk of diathermy burn and pressure necrosis. Sections of the operating table can be angled so that the patient is optimally positioned for the particular procedure (e.g. flexed while lying supine or on one side, head-down, head-up).
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== Endoscopy ==
+
==Endoscopy==
-
Endoscopy is performed by inserting a fibre-optic telescope containing a light source and instrument channels into the gastrointestinal, respiratory and urinary tracts. The operator undertakes the procedure by manipulating the endoscope while viewing a video screen or looking down the eye piece of the instrument.  
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Endoscopy is performed by inserting a fibre-optic telescope containing a light source and instrument channels into the gastrointestinal, respiratory and urinary tracts. The operator undertakes the procedure by manipulating the endoscope while viewing a video screen or looking down the eye piece of the instrument.
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=== Gastrointestinal endoscopy ===
+
===Gastrointestinal endoscopy===
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Endoscopy of the gastrointestinal tract allows the endoscopist to view the lumen of the oesophagus, stomach and proximal half of the duodenum (oesophagogastroduodenoscopy), colon (colonoscopy), and rectum and distal sigmod colon (sigmoidoscopy), and distal rectum and anal canal (proctoscopy). It is usually performed under sedation. Intestinal endoscopy can also be performed at laparotomy (enteroscopy) by making a small incision in the intestine and the surgeon passes the endoscope along the intestinal lumen. Procedures, such as dilatation of strictures, biospy and diathermy ablation of polyps, injection of adrenaline around bleeding gastric and duodenal ulcers, cholangio-pancreatography, removal of common bile duct calculi, injection of haemorrhoids, and tumour phototherapy can be performed using fibreoptic endoscopes.  
+
Endoscopy of the gastrointestinal tract allows the endoscopist to view the lumen of the oesophagus, stomach and proximal half of the duodenum (oesophagogastroduodenoscopy), colon (colonoscopy), and rectum and distal sigmod colon (sigmoidoscopy), and distal rectum and anal canal (proctoscopy). It is usually performed under sedation. Intestinal endoscopy can also be performed at laparotomy (enteroscopy) by making a small incision in the intestine and the surgeon passes the endoscope along the intestinal lumen. Procedures, such as dilatation of strictures, biospy and diathermy ablation of polyps, injection of adrenaline around bleeding gastric and duodenal ulcers, cholangio-pancreatography, removal of common bile duct calculi, injection of haemorrhoids, and tumour phototherapy can be performed using fibreoptic endoscopes.
-
=== Bronchoscopy ===
+
===Bronchoscopy===
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The upper airway, trachea and proximal bronchi can be inspected by bronchoscopy, which may be performed under local or general anaesthesia. Bronchoscopy is used for diagnosis (e.g. inspection and biopsy of lung tumours) or therapy (e.g. removal of foreign bodies, aspiration of secretions). Anaesthetists ocassionally use the fibre-optic bronchoscope to facilitate difficult endotracheal intubation. (see also [[Common topics in thoracic surgery#ch58|''Common topics in thoracic surgery'']]).  
+
The upper airway, trachea and proximal bronchi can be inspected by bronchoscopy, which may be performed under local or general anaesthesia. Bronchoscopy is used for diagnosis (e.g. inspection and biopsy of lung tumours) or therapy (e.g. removal of foreign bodies, aspiration of secretions). Anaesthetists ocassionally use the fibre-optic bronchoscope to facilitate difficult endotracheal intubation. (see also [[Common%20topics%20in%20thoracic%20surgery#ch58|''Common topics in thoracic surgery'']]).
-
=== Urological endoscopy ===
+
===Urological endoscopy===
-
The urethra (urethroscopy), bladder (cystoscopy), and ureters (ureteroscopy) can be inspected for diagnostic purposes. Extensive therapeutic procedures (e.g. resection of the prostate, diathermy and excision of bladder tumours, extraction of calculi) can be performed safely with far less morbidity than the equivalent open procedures.  
+
The urethra (urethroscopy), bladder (cystoscopy), and ureters (ureteroscopy) can be inspected for diagnostic purposes. Extensive therapeutic procedures (e.g. resection of the prostate, diathermy and excision of bladder tumours, extraction of calculi) can be performed safely with far less morbidity than the equivalent open procedures.
-
== Endoscopic surgery ==
+
==Endoscopic surgery==
-
Endoscopic surgery is performed by inserting a microchip video camera with a light source and specially crafted long-handled surgical instruments into a body cavity by way of small incisions. The surgeon undertakes the procedure by manipulating the instruments while viewing a video screen.  
+
Endoscopic surgery is performed by inserting a microchip video camera with a light source and specially crafted long-handled surgical instruments into a body cavity by way of small incisions. The surgeon undertakes the procedure by manipulating the instruments while viewing a video screen.
-
The advantages of endoscopic or ‘closed’ surgery are reduced post-operative pain and analgesic requirements, earlier discharge from hospital, and earlier return to normal function. However, many surgical procedures either cannot be undertaken endoscopically because of their very nature, or cannot be completed endoscopically because of difficulty or patient safety, in which case the operation is converted to an ‘open’ procedure. Some procedures use endoscopic techniques to assist with the procedure and an incision is made to either complete the operation or deliver the resected specimen (e.g. bowel resection, nephrectomy, splenectomy). The range of endoscopically performed operations in many surgical specialties has increased enormously over the last 10–15 years.  
+
The advantages of endoscopic or ‘closed’ surgery are reduced post-operative pain and analgesic requirements, earlier discharge from hospital, and earlier return to normal function. However, many surgical procedures either cannot be undertaken endoscopically because of their very nature, or cannot be completed endoscopically because of difficulty or patient safety, in which case the operation is converted to an ‘open’ procedure. Some procedures use endoscopic techniques to assist with the procedure and an incision is made to either complete the operation or deliver the resected specimen (e.g. bowel resection, nephrectomy, splenectomy). The range of endoscopically performed operations in many surgical specialties has increased enormously over the last 10–15 years.
-
=== Abdominal surgery ===
+
===Abdominal surgery===
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''Laparoscopy'' refers to the technique of insufflating the peritoneal cavity with gas, inserting a camera through a 10–15-mm sub-umbilical incision and inspecting the abdominal contents. Usually, three additional ports are inserted through 5–10-mm incisions in the abdominal wall and instruments (e.g. scissors, grasping devices, retractors, staplers, needle holders) are introduced and manipulated by the surgeon to perform the operation. Procedures such as cholecystectomy, gastric fundoplication, hiatus hernia repair, division of adhesions, appendicectomy, splenectomy, adrenalectomy, nephrectomy, oophorectomy, tubal ligation, and hernia repair can be undertaken laparoscopically with less morbidity than if undertaken as an open or conventional operation. Endoscopic surgery has allowed some procedures to be undertaken as day cases, whereas the same procedure performed as an open operation would require an inpatient stay of several days (e.g. cholecystectomy, hernia repair).  
+
''Laparoscopy'' refers to the technique of insufflating the peritoneal cavity with gas, inserting a camera through a 10–15-mm sub-umbilical incision and inspecting the abdominal contents. Usually, three additional ports are inserted through 5–10-mm incisions in the abdominal wall and instruments (e.g. scissors, grasping devices, retractors, staplers, needle holders) are introduced and manipulated by the surgeon to perform the operation. Procedures such as cholecystectomy, gastric fundoplication, hiatus hernia repair, division of adhesions, appendicectomy, splenectomy, adrenalectomy, nephrectomy, oophorectomy, tubal ligation, and hernia repair can be undertaken laparoscopically with less morbidity than if undertaken as an open or conventional operation. Endoscopic surgery has allowed some procedures to be undertaken as day cases, whereas the same procedure performed as an open operation would require an inpatient stay of several days (e.g. cholecystectomy, hernia repair).
-
=== Thoracic surgery ===
+
===Thoracic surgery===
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Thorascopy involves inserting a camera with a light source and instruments into the thoracic cavity. The technique is used diagnostically and therapeutically for procedures such as drainage of the thoracic cavity (haemothorax, pleural effusion and empyema), lung biopsy, pleurodesis, and excision of lung bullae. The mediastinum can be inspected and mediastinal lymph nodes can be biopsied by mediastinoscopy, which may prevent the need for an exploratory thoracotomy.  
+
Thorascopy involves inserting a camera with a light source and instruments into the thoracic cavity. The technique is used diagnostically and therapeutically for procedures such as drainage of the thoracic cavity (haemothorax, pleural effusion and empyema), lung biopsy, pleurodesis, and excision of lung bullae. The mediastinum can be inspected and mediastinal lymph nodes can be biopsied by mediastinoscopy, which may prevent the need for an exploratory thoracotomy.
-
=== Orthopaedic surgery ===
+
===Orthopaedic surgery===
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Large joints (e.g. knee, hip, ankle, shoulder, wrist) can be inspected by arthroscopy. Therapeutic procedures include removal of bone chips, cartilage excision and removal, and ligament repair. Arthroscopic surgery has been enormously beneficial for orthopaedic patients and has allowed far more rapid return to function.  
+
Large joints (e.g. knee, hip, ankle, shoulder, wrist) can be inspected by arthroscopy. Therapeutic procedures include removal of bone chips, cartilage excision and removal, and ligament repair. Arthroscopic surgery has been enormously beneficial for orthopaedic patients and has allowed far more rapid return to function.
-
=== Open surgery ===
+
===Open surgery===
-
Open surgery is the traditional or conventional method of operating. In general terms, open surgery involves making a surgical wound, dissecting tissues to gain access to and mobility of the structure or organ of interest, completing the therapeutic procedure, ensuring haemostasis is complete, and then closing the wound with sutures. Open surgey is performed more with the hands and direct touch than endoscopic procedures, and fingers may be used for ‘blunt’ dissection. The surgical wound accounts for much of the morbidity of open surgery, particularly the cutting of muscle. The range of open operations is extremely wide, as evidenced by the procedures described throughout this book.  
+
Open surgery is the traditional or conventional method of operating. In general terms, open surgery involves making a surgical wound, dissecting tissues to gain access to and mobility of the structure or organ of interest, completing the therapeutic procedure, ensuring haemostasis is complete, and then closing the wound with sutures. Open surgey is performed more with the hands and direct touch than endoscopic procedures, and fingers may be used for ‘blunt’ dissection. The surgical wound accounts for much of the morbidity of open surgery, particularly the cutting of muscle. The range of open operations is extremely wide, as evidenced by the procedures described throughout this book.
-
== Surgical methods ==
+
==Surgical methods==
-
Surgical operations are performed by well worked out, standardised steps which progress in logical sequence. An operative plan is worked out by the surgeon for every operation.  
+
Surgical operations are performed by well worked out, standardised steps which progress in logical sequence. An operative plan is worked out by the surgeon for every operation.
-
=== Surgical instruments ===
+
===Surgical instruments===
-
There are literally thousands of surgical instruments, some simple and others extremely complex, but each designed for a specific function. The surgical incison is made with a scalpel which consists of a re-usable handle and a disposable blade. Scissors are used to cut other tissues and sutures, and for blunt dissection with the blades closed. Diathermy is used for haemostasis and to cut through tissue layers beneath the skin. Tissues are held with dissecting or tissue grasping forceps rather than the fingers. Hand-held forceps either have teeth which tend to dig into and damage tissues, or are non-toothed with poorer grasping ability. Needle holders are used to grasp needles for suturing and eliminate the need for hand-held needles, and are therefore safer. They have a ratchet so that the needle can be contained securely in the holder while not in the surgeon's hand. Retractors allow the surgeon to operate in an adequately exposed field. Self-retaining retractors keep the wound edges apart without the aid of an assistant. Retractors held by the assistant provide tissue retraction in awkward parts of the wound and in situations where retraction of specific tissues is required so that intricate parts of the operation can be performed. A sucker is used to aspirate blood and body fluids from the operative field and to remove smoke created by the diathermy. There are many instruments designed specifically for surgical specialties and procedures.  
+
There are literally thousands of surgical instruments, some simple and others extremely complex, but each designed for a specific function. The surgical incison is made with a scalpel which consists of a re-usable handle and a disposable blade. Scissors are used to cut other tissues and sutures, and for blunt dissection with the blades closed. Diathermy is used for haemostasis and to cut through tissue layers beneath the skin. Tissues are held with dissecting or tissue grasping forceps rather than the fingers. Hand-held forceps either have teeth which tend to dig into and damage tissues, or are non-toothed with poorer grasping ability. Needle holders are used to grasp needles for suturing and eliminate the need for hand-held needles, and are therefore safer. They have a ratchet so that the needle can be contained securely in the holder while not in the surgeon's hand. Retractors allow the surgeon to operate in an adequately exposed field. Self-retaining retractors keep the wound edges apart without the aid of an assistant. Retractors held by the assistant provide tissue retraction in awkward parts of the wound and in situations where retraction of specific tissues is required so that intricate parts of the operation can be performed. A sucker is used to aspirate blood and body fluids from the operative field and to remove smoke created by the diathermy. There are many instruments designed specifically for surgical specialties and procedures.
-
=== Incisions ===
+
===Incisions===
-
Surgical incisions are made so that:  
+
Surgical incisions are made so that:
-
*The operation can be undertaken with adequate exposure of the area or structure of interest.  
+
* The operation can be undertaken with adequate exposure of the area or structure of interest.
-
*The procedure can be performed and completed safely and expeditiously.  
+
* The procedure can be performed and completed safely and expeditiously.
-
*The wound heals satisfactorily with a cosmetically acceptable scar.
+
* The wound heals satisfactorily with a cosmetically acceptable scar.
-
Thus, incisions are to be of adequate but not excessive length and, if possible, placed in skin creases, particularly when operating on exposed areas of the body such as the face, neck and breast. Parallel skin incisions (tram tracking) and V- or T-shaped incisions are avoided because of ischaemia of intervening tissue and pointed flaps.  
+
Thus, incisions are to be of adequate but not excessive length and, if possible, placed in skin creases, particularly when operating on exposed areas of the body such as the face, neck and breast. Parallel skin incisions (tram tracking) and V- or T-shaped incisions are avoided because of ischaemia of intervening tissue and pointed flaps.
-
=== Tissue dissection ===
+
===Tissue dissection===
-
Ideally, surgical dissection should be performed along tissue planes which tend to be relatively avascular. The aim is to isolate (mobilise) the structure(s) of interest from surrounding connective tissue and other structures with the least amount of trauma and bleeding. Tissues should be handled with great care and respect and as little as possible. Dissection is undertaken by using a scalpel or scissor (sharp dissection), a finger, closed scissor, gauze pledget, or scalpel handle (blunt dissection), or the diathermy. Gentle counter traction on tissues by the assistant facilitates the dissection.  
+
Ideally, surgical dissection should be performed along tissue planes which tend to be relatively avascular. The aim is to isolate (mobilise) the structure(s) of interest from surrounding connective tissue and other structures with the least amount of trauma and bleeding. Tissues should be handled with great care and respect and as little as possible. Dissection is undertaken by using a scalpel or scissor (sharp dissection), a finger, closed scissor, gauze pledget, or scalpel handle (blunt dissection), or the diathermy. Gentle counter traction on tissues by the assistant facilitates the dissection.
-
=== Haemostasis ===
+
===Haemostasis===
-
''Surgical haemostasis'' refers to stopping bleeding which occurs with transection of blood vessels. The majority of cases of operative and post-operative bleeding are due to inadequate surgical haemostasis rather than disorders of clotting and coagulation. Haemostasis is essential in order to prevent blood loss during surgery and haematoma formation post-operatively. Methods of surgical haemostasis include:  
+
''Surgical haemostasis'' refers to stopping bleeding which occurs with transection of blood vessels. The majority of cases of operative and post-operative bleeding are due to inadequate surgical haemostasis rather than disorders of clotting and coagulation. Haemostasis is essential in order to prevent blood loss during surgery and haematoma formation post-operatively. Methods of surgical haemostasis include:
-
*Application of a haemostatic clamp to a blood vessel and then ligation with a surgical ligature (see [[Care of the critically ill patient#ch6|''Care of the critically ill patient'']]).  
+
* Application of a haemostatic clamp to a blood vessel and then ligation with a surgical ligature (see [[Care%20of%20the%20critically%20ill%20patient#ch6|''Care of the critically ill patient'']]).
-
*Suture ligation of a vessel - under-running a bleeding vessel with a figure-of-8 suture which is tied firmly.  
+
* Suture ligation of a vessel - under-running a bleeding vessel with a figure-of-8 suture which is tied firmly.
-
*Diathermy coagulation (see [[Anaesthesia and pain management#ch2|''Anaesthesia and pain management'']]).  
+
* Diathermy coagulation (see [[Anaesthesia%20and%20pain%20management#ch2|''Anaesthesia and pain management'']]).
-
*Localised pressure for several minutes to allow coagulation to occur naturally.  
+
* Localised pressure for several minutes to allow coagulation to occur naturally.
-
*Application of surgical materials (e.g. oxidised cellulose, Surgicell) which promote coagulation.  
+
* Application of surgical materials (e.g. oxidised cellulose, Surgicell) which promote coagulation.
-
*Application of topical agents to promote vasoconstriction (e.g. adrenaline) or coagulation (e.g. thrombin).  
+
* Application of topical agents to promote vasoconstriction (e.g. adrenaline) or coagulation (e.g. thrombin).
-
*Packing of a bleeding cavity with gauze packs as a temporary measure until definitive haemostasis can be achieved.
+
* Packing of a bleeding cavity with gauze packs as a temporary measure until definitive haemostasis can be achieved.
-
=== Sutures ===
+
===Sutures===
 +
 
 +
Sutures have been used to close surgical wounds for thousands of years, and initially were made from human or animal hair, animal sinews, and plant material. Today, a wide variety of material is available for suturing and ligating tissues ([[Surgical%20techniques#ch4-box3|Sutures]]).
-
Sutures have been used to close surgical wounds for thousands of years, and initially were made from human or animal hair, animal sinews, and plant material. Today, a wide variety of material is available for suturing and ligating tissues ([[Surgical techniques#ch4-box3|Sutures]]).
 
<div id="ch4-box3" class="sidebar"><div class="title">
<div id="ch4-box3" class="sidebar"><div class="title">
-
'''Sutures'''  
+
 
-
</div>  
+
'''Sutures'''
 +
 
 +
</div>
 +
 
{| id="id36072077"
{| id="id36072077"
-
|+ Table&nbsp;8.&nbsp;Box 4.3 Sutures  
+
|+ Table 8. Box 4.3 Sutures
|-
|-
-
! align="left" | Substance  
+
! align="left" | Substance
-
! align="left" | Description*  
+
! align="left" | Description*
-
! align="left" | Duration<sup>+</sup>  
+
! align="left" | Duration<sup>+</sup>
-
! align="left" | Trade name  
+
! align="left" | Trade name
-
! align="left" | Uses  
+
! align="left" | Uses
| colspan="5" | * Synthetic (Syn), Natural (Nat), Monofilament (Mono), Multifilament (Multi), Absorbable (Ab), Non-absorbable (Non).
| colspan="5" | * Synthetic (Syn), Natural (Nat), Monofilament (Mono), Multifilament (Multi), Absorbable (Ab), Non-absorbable (Non).
|-
|-
| colspan="5" | + Time during which tensile strength is maintained.
| colspan="5" | + Time during which tensile strength is maintained.
|-
|-
-
| Plain catgut  
+
| Plain catgut
-
| Nat, Multi, Ab  
+
| Nat, Multi, Ab
-
| 1–2 weeks  
+
| 1–2 weeks
-
| -  
+
| -
| Subcutaneous fat
| Subcutaneous fat
|-
|-
-
| Chromic catgut  
+
| Chromic catgut
-
| Nat, Multi, Ab  
+
| Nat, Multi, Ab
-
| 2–3 weeks  
+
| 2–3 weeks
-
| -  
+
| -
| Subcutaneous fat, gastrointestinal and urinary tract anastomoses
| Subcutaneous fat, gastrointestinal and urinary tract anastomoses
|-
|-
-
| Silk and linen  
+
| Silk and linen
-
| Nat, Multi, Non  
+
| Nat, Multi, Non
-
| Prolonged  
+
| Prolonged
-
| -  
+
| -
| Skin and cardiac sutures, ligatures
| Skin and cardiac sutures, ligatures
|-
|-
-
| Stainless steel  
+
| Stainless steel
-
| Nat, Mono, Non  
+
| Nat, Mono, Non
-
| Prolonged  
+
| Prolonged
-
| -  
+
| -
| Sternum, skin and gastrointestinal staples, orthopaedic wire,
| Sternum, skin and gastrointestinal staples, orthopaedic wire,
|-
|-
-
| Polyglycolic acid  
+
| Polyglycolic acid
-
| Syn, Multi, Ab  
+
| Syn, Multi, Ab
-
| 3–4 weeks  
+
| 3–4 weeks
-
| Dexon  
+
| Dexon
| Gastrointestinal and urinary tracts, muscle, fascia, subcutaneous fat
| Gastrointestinal and urinary tracts, muscle, fascia, subcutaneous fat
|-
|-
-
| Polyglactin  
+
| Polyglactin
-
| Syn, Multi, Ab  
+
| Syn, Multi, Ab
-
| 4–6 weeks  
+
| 4–6 weeks
-
| Vicryl  
+
| Vicryl
| Gastrointestinal and urinary tracts, muscle, fascia, subcutaneous fat
| Gastrointestinal and urinary tracts, muscle, fascia, subcutaneous fat
|-
|-
-
| Polypropylene  
+
| Polypropylene
-
| Syn, Mono, Non  
+
| Syn, Mono, Non
-
| Indefinite  
+
| Indefinite
-
| Prolene  
+
| Prolene
| Ophthalmology, vascular sutures, abdominal closure, neurosurgery, fascia, skin
| Ophthalmology, vascular sutures, abdominal closure, neurosurgery, fascia, skin
|-
|-
-
| Polyamide  
+
| Polyamide
-
| Syn, Mono, Non  
+
| Syn, Mono, Non
-
| Years  
+
| Years
-
| Nylon  
+
| Nylon
| Abdominal and skin closure, hernia repair
| Abdominal and skin closure, hernia repair
|-
|-
-
| Polytetrafluoroethylene (PTFE)  
+
| Polytetrafluoroethylene (PTFE)
-
| Syn, Mono, Non  
+
| Syn, Mono, Non
-
| Indefinite  
+
| Indefinite
-
| Gortex  
+
| Gortex
| Vascular anastomoses, hernia repair
| Vascular anastomoses, hernia repair
|}
|}
-
</div>
 
-
Sutures are selected for use according to the required function. For example, arteries are sutured together with non-absorbable polypropylene or polytetrafluoroethylene (PTFE) sutures which are nonthrombogenic, cause virtually no tissue reaction, and maintain their instrinsic strength indefinitely so that the anastomotic scar (which is under constant arterial pressure) does not stretch and become aneurysmal. Skin wounds, for example, are sutured with either non-absorbable sutures, which are removed after several days (see [[Care of the critically ill patient#ch6|''Care of the critically ill patient'']]), or absorbable sutures hidden within the skin (subcuticular sutures) and which are not removed surgically but are absorbed after several weeks.
 
-
Sutures are available in diameters ranging from 0.02–0.50 mm. The minimum calibre of suture should be used, compatible with its function. Non-absorbable sutures are avoided for suturing the luminal aspects of the gastrointestinal and urinary tracts because substances within the contained fluids (e.g. bile, urine) may precipitate on persisting sutures and produce calculi.
+
</div>
-
The requirements of suture material are:
+
Sutures are selected for use according to the required function. For example, arteries are sutured together with non-absorbable polypropylene or polytetrafluoroethylene (PTFE) sutures which are nonthrombogenic, cause virtually no tissue reaction, and maintain their instrinsic strength indefinitely so that the anastomotic scar (which is under constant arterial pressure) does not stretch and become aneurysmal. Skin wounds, for example, are sutured with either non-absorbable sutures, which are removed after several days (see [[Care%20of%20the%20critically%20ill%20patient#ch6|''Care of the critically ill patient'']]), or absorbable sutures hidden within the skin (subcuticular sutures) and which are not removed surgically but are absorbed after several weeks.
-
*Tensile strength - the suture must be strong enough to hold tissues in apposition for as long as required.  
+
Sutures are available in diameters ranging from 0.02–0.50 mm. The minimum calibre of suture should be used, compatible with its function. Non-absorbable sutures are avoided for suturing the luminal aspects of the gastrointestinal and urinary tracts because substances within the contained fluids (e.g. bile, urine) may precipitate on persisting sutures and produce calculi.
-
*Durability - the suture must remain until either healing is advanced or indefinitely if the healed tissue is under constant pressure.  
+
-
*Reactivity - tissue reaction (i.e. an inflammatory response) allows absorbable sutures to be removed by phagocytosis but results in chronic inflammation if non-absorbable sutures remain ''in situ''.
+
-
*Handling characteristics - sutures must be easy to grasp, handle and tie.  
+
-
*Knot security - sutures must be able to be tied effectively so that knots do not come undone or slip. Sutures are classified as:
+
-
*Absorbable or non-absorbable. The rate of absorption of absorbable sutures depends on what they are made of and their thickness. Disappearance of the suture occurs through inflammatory reaction, hydrolysis or enzymatic degradation.
+
-
*Synthetic or natural material. Sutures of natural (animal) origin are being phased out of surgical practice because of the very minimal risk of disease transmission. A wide variety of synthetic suture materials are available.  
+
-
*Monofilament or multifilament. Monofilament sutures pass through tissues easily, are generally less reactive, and are more difficult to handle and knot securely. Multifilament sutures are braided or twisted thread, and are easier to handle and knot, but are more likely to harbour micro-organisms within the suture.
+
-
=== Surgical knots ===
+
The requirements of suture material are:
-
Knots are tied to ensure that ligatures and sutures remain in place and do not slip or unravel. The ability to tie a secure knot is a fundamental technique in surgery, and patients' lives literally depend on knot security (e.g. the knot in a ligature used to tie off an artery). Knot security depends on friction between the throws of the ligature material, the number of throws used to tie the knot, the strength of the ligature material, and the tightness of the knot. Usually, multiple throws are used to secure the knot (e.g. two reef knots, one on the other).  
+
* Tensile strength - the suture must be strong enough to hold tissues in apposition for as long as required.
 +
* Durability - the suture must remain until either healing is advanced or indefinitely if the healed tissue is under constant pressure.
 +
* Reactivity - tissue reaction (i.e. an inflammatory response) allows absorbable sutures to be removed by phagocytosis but results in chronic inflammation if non-absorbable sutures remain ''in situ''.
 +
* Handling characteristics - sutures must be easy to grasp, handle and tie.
 +
* Knot security - sutures must be able to be tied effectively so that knots do not come undone or slip. Sutures are classified as:
 +
* Absorbable or non-absorbable. The rate of absorption of absorbable sutures depends on what they are made of and their thickness. Disappearance of the suture occurs through inflammatory reaction, hydrolysis or enzymatic degradation.
 +
* Synthetic or natural material. Sutures of natural (animal) origin are being phased out of surgical practice because of the very minimal risk of disease transmission. A wide variety of synthetic suture materials are available.
 +
* Monofilament or multifilament. Monofilament sutures pass through tissues easily, are generally less reactive, and are more difficult to handle and knot securely. Multifilament sutures are braided or twisted thread, and are easier to handle and knot, but are more likely to harbour micro-organisms within the suture.
-
=== Suturing ===
+
===Surgical knots===
-
The technique of suturing depends on the tissue and wound being sutured. Sutures may be either continuous (e.g. subcuticular skin sutures, abdominal closure, vascular anastomosis), or interrupted (e.g. skin sutures, sternal wires). The function of sutures is to hold the adjacent edges of sutured tissues in apposition and to immobilise them in that position so that wound healing (i.e. neovascularisation, connective tissue ingrowth and collagen formation) is facilitated. It is essential that sutures are not tied so tightly that the tissues encompassed by them become ischaemic. Skin sutures may be supported by adhesive paper tapes.  
+
Knots are tied to ensure that ligatures and sutures remain in place and do not slip or unravel. The ability to tie a secure knot is a fundamental technique in surgery, and patients' lives literally depend on knot security (e.g. the knot in a ligature used to tie off an artery). Knot security depends on friction between the throws of the ligature material, the number of throws used to tie the knot, the strength of the ligature material, and the tightness of the knot. Usually, multiple throws are used to secure the knot (e.g. two reef knots, one on the other).
-
Retention sutures (incorrectly referred to as ''tension sutures'') are used to close abdominal incisions which are thought to be at increased risk of dehiscence, and are inserted to encompass a large amount of fascial tissue and are placed 3–5 cm apart.
+
===Suturing===
-
Within the last two decades, stainless steel staples have been used to close skin wounds and to perform gastrointestinal anastomoses. Staples are quicker to use than sutures, but are relatively expensive and produce a worse cosmetic result for skin closure than subcuticular absorbable sutures.  
+
The technique of suturing depends on the tissue and wound being sutured. Sutures may be either continuous (e.g. subcuticular skin sutures, abdominal closure, vascular anastomosis), or interrupted (e.g. skin sutures, sternal wires). The function of sutures is to hold the adjacent edges of sutured tissues in apposition and to immobilise them in that position so that wound healing (i.e. neovascularisation, connective tissue ingrowth and collagen formation) is facilitated. It is essential that sutures are not tied so tightly that the tissues encompassed by them become ischaemic. Skin sutures may be supported by adhesive paper tapes.
-
=== Suture removal ===
+
Retention sutures (incorrectly referred to as ''tension sutures'') are used to close abdominal incisions which are thought to be at increased risk of dehiscence, and are inserted to encompass a large amount of fascial tissue and are placed 3–5 cm apart.
 +
 
 +
Within the last two decades, stainless steel staples have been used to close skin wounds and to perform gastrointestinal anastomoses. Staples are quicker to use than sutures, but are relatively expensive and produce a worse cosmetic result for skin closure than subcuticular absorbable sutures.
 +
 
 +
===Suture removal===
 +
 
 +
Sutures are removed as early as possible to minimise the risk of infection and scarring, so long as tissue healing is sufficently advanced that the wound will not open when the sutures are removed. Sutures are therefore removed at different times, depending on tissue and general patient factors ([[Surgical%20techniques#ch4-box4|Timing of suture removal]]). for example, sutures are left ''in situ'' for a longer time in patients who are immunosuppressed, malnourished, jaundiced, or undergoing chemotherapy; who have renal failure, and in tissues judged to be relatively ischaemic, subject to increased stress and tension, and which have been irradiated.
-
Sutures are removed as early as possible to minimise the risk of infection and scarring, so long as tissue healing is sufficently advanced that the wound will not open when the sutures are removed. Sutures are therefore removed at different times, depending on tissue and general patient factors ([[Surgical techniques#ch4-box4|Timing of suture removal]]). for example, sutures are left ''in situ'' for a longer time in patients who are immunosuppressed, malnourished, jaundiced, or undergoing chemotherapy; who have renal failure, and in tissues judged to be relatively ischaemic, subject to increased stress and tension, and which have been irradiated.
 
<div id="ch4-box4" class="sidebar"><div class="title">
<div id="ch4-box4" class="sidebar"><div class="title">
-
'''Timing of suture removal'''  
+
 
-
</div>  
+
'''Timing of suture removal'''
 +
 
 +
</div>
 +
 
{| id="id36072516"
{| id="id36072516"
-
|+ Table&nbsp;9.&nbsp;Box 4.4 Timing of suture removal  
+
|+ Table 9. Box 4.4 Timing of suture removal
|-
|-
-
! align="left" | Site  
+
! align="left" | Site
! Time of removal (days)
! Time of removal (days)
|-
|-
-
| Face  
+
| Face
| align="center" | 3–5
| align="center" | 3–5
|-
|-
-
| Neck (skin crease)  
+
| Neck (skin crease)
| align="center" | 5–7
| align="center" | 5–7
|-
|-
-
| Scalp  
+
| Scalp
| align="center" | 7–10
| align="center" | 7–10
|-
|-
-
| Abdomen  
+
| Abdomen
| align="center" | 10
| align="center" | 10
|-
|-
-
| Extremity  
+
| Extremity
| align="center" | 10–14
| align="center" | 10–14
|-
|-
-
| Amputation stump  
+
| Amputation stump
| align="center" | 21
| align="center" | 21
|}
|}
-
</div>
 
-
== Surgical drains ==
 
-
Drains are used widely in surgical practice to  
+
</div>
 +
 
 +
==Surgical drains==
 +
 
 +
Drains are used widely in surgical practice to
 +
 
 +
* Remove blood or serous fluid, which would otherwise accumulate in the operative area (e.g. wound drain).
 +
* Provide a track or line of minimal resistance so that potentially harmful fluids can drain away from a particular site (e.g. drain placed into an intra-abdominal abscess cavity).
-
*Remove blood or serous fluid, which would otherwise accumulate in the operative area (e.g. wound drain).
+
Several different methods of drainage may be used depending on the required function.
-
*Provide a track or line of minimal resistance so that potentially harmful fluids can drain away from a particular site (e.g. drain placed into an intra-abdominal abscess cavity).
+
-
Several different methods of drainage may be used depending on the required function.  
+
* Open drainage - a drain tube or strip of soft flexible latex rubber is placed so secretions or pus can drain along the track of the drain into gauze or other dressing covering the external end of the drain tube (e.g. drain placed in an abscess cavity, drain placed prohylactically near a bowel anastomosis in case of subsequent anastomotic leak).
 +
* Closed drainage - a tube is placed into an area or viscus to drain fluid contents into a collecting bag so that there is no contamination of the drained area from outside the system (e.g. chest drain, urinary catheter, cholecystostomy drain).
 +
* Closed suction drain - the drain tube is connected to a bottle at negative atmospheric pressure so that fluid is sucked out of the area (e.g. wound drain, drain under skin flaps).
-
*Open drainage - a drain tube or strip of soft flexible latex rubber is placed so secretions or pus can drain along the track of the drain into gauze or other dressing covering the external end of the drain tube (e.g. drain placed in an abscess cavity, drain placed prohylactically near a bowel anastomosis in case of subsequent anastomotic leak).  
+
It is important to note both the amount and the type of fluid which drains. Large volumes of fluid drainage may need to be replaced as intravenous fluids (e.g. duo-denal fistula fluid). Depending on the particular situation, it may be necessary to culture drain fluid or send it for estimation of haemoglobin, creatinine, electrolytes, amylase or protein. A radiological contrast study may be performed along the drain tube, for example to estimate the size of a cavity being drained.
-
*Closed drainage - a tube is placed into an area or viscus to drain fluid contents into a collecting bag so that there is no contamination of the drained area from outside the system (e.g. chest drain, urinary catheter, cholecystostomy drain).  
+
-
*Closed suction drain - the drain tube is connected to a bottle at negative atmospheric pressure so that fluid is sucked out of the area (e.g. wound drain, drain under skin flaps).
+
-
It is important to note both the amount and the type of fluid which drains. Large volumes of fluid drainage may need to be replaced as intravenous fluids (e.g. duo-denal fistula fluid). Depending on the particular situation, it may be necessary to culture drain fluid or send it for estimation of haemoglobin, creatinine, electrolytes, amylase or protein. A radiological contrast study may be performed along the drain tube, for example to estimate the size of a cavity being drained.  
+
Drain tubes are removed when they are no longer required, for example when there is minimal fluid being drained, or when a cavity being drained has contracted and is small. Drains are removed simply by cutting the suture which anchors them to the skin and withdrawing the tube from the patient.
-
Drain tubes are removed when they are no longer required, for example when there is minimal fluid being drained, or when a cavity being drained has contracted and is small. Drains are removed simply by cutting the suture which anchors them to the skin and withdrawing the tube from the patient.
+
==Venepuncture==
-
== Venepuncture ==
+
Venepuncture involves removing blood from a superficial vein, usually in the antecubital fossa or dorsum of the hand, by inserting a needle attached to a syringe or collection tube at negative pressure (vacutainer system). A venous torniquet is applied around the arm, which is hung in a dependent position; the patient vigorously opens and closes the hand, and the vein is gently patted to encourage venous dilatation. The skin is cleansed with antiseptic and the needle is inserted through the skin into the dilated vein at an angle of 30–45 degrees. Only the required volume is aspirated, the torniquet is released, the needle is withdrawn, the puncture site is immediately covered with a cotton wool swab, and light pressure is applied for 1–2 minutes. The site is covered with an adhesive dressing. Complications include bruising, haematoma, and rarely, infection and damage to deeper structures. Inadvertent needlestick injury to the venepuncturist is avoided by careful technique.
-
Venepuncture involves removing blood from a superficial vein, usually in the antecubital fossa or dorsum of the hand, by inserting a needle attached to a syringe or collection tube at negative pressure (vacutainer system). A venous torniquet is applied around the arm, which is hung in a dependent position; the patient vigorously opens and closes the hand, and the vein is gently patted to encourage venous dilatation. The skin is cleansed with antiseptic and the needle is inserted through the skin into the dilated vein at an angle of 30–45 degrees. Only the required volume is aspirated, the torniquet is released, the needle is withdrawn, the puncture site is immediately covered with a cotton wool swab, and light pressure is applied for 1–2 minutes. The site is covered with an adhesive dressing. Complications include bruising, haematoma, and rarely, infection and damage to deeper structures. Inadvertent needlestick injury to the venepuncturist is avoided by careful technique.
+
==Intravenous cannulation==
-
== Intravenous cannulation ==
+
Intravenous (i.v.) cannulation is used commonly for administration of fluids and drugs. Superficial veins on the forearms and dorsum of the hands are used for i.v. cannulation. Antecubital fossa veins are best avoided for cannulation because the elbow has to be kept extended to avoid kinking of the cannula. Leg veins may have to be used in the absence of useable upper limb veins. Cannulas have a soft outer Teflon sheath attached to a hub, and a central hollow needle attached to a small chamber.
-
Intravenous (i.v.) cannulation is used commonly for administration of fluids and drugs. Superficial veins on the forearms and dorsum of the hands are used for i.v. cannulation. Antecubital fossa veins are best avoided for cannulation because the elbow has to be kept extended to avoid kinking of the cannula. Leg veins may have to be used in the absence of useable upper limb veins. Cannulas have a soft outer Teflon sheath attached to a hub, and a central hollow needle attached to a small chamber.  
+
A suitable vein is identified as for venepuncture. Local anaesthetic cream is applied to the skin overlying the vein or local anaesthetic (1% lignocaine without adrenaline) is injected intradermally next to the vein after cleansing the skin with antiseptic. The cannula (needle and sheath) is inserted through the skin into the vein at an angle of 10–30 degrees and advanced into the vein in the same movement. The needle is removed from the sheath and a closed three-way tap or i.v. giving set is joined to the hub of the sheath. The cannula is secured to the skin with adhesive tape.
-
A suitable vein is identified as for venepuncture. Local anaesthetic cream is applied to the skin overlying the vein or local anaesthetic (1% lignocaine without adrenaline) is injected intradermally next to the vein after cleansing the skin with antiseptic. The cannula (needle and sheath) is inserted through the skin into the vein at an angle of 10–30 degrees and advanced into the vein in the same movement. The needle is removed from the sheath and a closed three-way tap or i.v. giving set is joined to the hub of the sheath. The cannula is secured to the skin with adhesive tape.  
+
Intravenous infusion is painful when the infusate is cold or contains irritants (e.g. potassium, calcium, drugs of low or high pH), or if the cannula pierces the vein wall and fluid extravasates subcutaneously. Thrombophlebitis develops at the insertion site after about three days, and i.v. cannulas should be re-sited if infusions are required for longer periods.
-
Intravenous infusion is painful when the infusate is cold or contains irritants (e.g. potassium, calcium, drugs of low or high pH), or if the cannula pierces the vein wall and fluid extravasates subcutaneously. Thrombophlebitis develops at the insertion site after about three days, and i.v. cannulas should be re-sited if infusions are required for longer periods.
+
==Central venous catheterisation==
-
== Central venous catheterisation ==
+
Percutaneous catheterisation of a central vein is used for
-
Percutaneous catheterisation of a central vein is used for
+
* Short- or long-term venous access when peripheral veins are unsuitable or cannot be used (e.g. prolonged fluid infusion, total parenteral nutrition, ultrafiltration, haemodialysis, plasma exchange, chemotherapy).
 +
* Short-term monitoring of central venous pressure A central venous catheter (CVC) may be inserted into the internal or external jugular vein or the subclavian vein. Temporary CVCs are made of semi-rigid Teflon, are approximately 25 cm in length and, depending on their function, are between 1 and 4 mm in diameter and have one, two or three lumens. Long-term CVCs are made of barium-impregnated silastic and are quite flexible. They have a Dacron cuff bonded to the part of the catheter which lies subcutaneously and becomes incorporated by fibrous tissue after several weeks so that organisms cannot track along the catheter from the skin into the circulation.
-
*Short- or long-term venous access when peripheral veins are unsuitable or cannot be used (e.g. prolonged fluid infusion, total parenteral nutrition, ultrafiltration, haemodialysis, plasma exchange, chemotherapy).
+
Some long-term single lumen CVCs are available with a small volume chamber attached to the extravenous end of the catheter (Portacath, Infusaport). The chamber is implanted subcutaneously after the vein is catheterised and can be accessed for chemotherapy or blood sampling by inserting a needle into it through the skin.
-
*Short-term monitoring of central venous pressure A central venous catheter (CVC) may be inserted into the internal or external jugular vein or the subclavian vein. Temporary CVCs are made of semi-rigid Teflon, are approximately 25 cm in length and, depending on their function, are between 1 and 4 mm in diameter and have one, two or three lumens. Long-term CVCs are made of barium-impregnated silastic and are quite flexible. They have a Dacron cuff bonded to the part of the catheter which lies subcutaneously and becomes incorporated by fibrous tissue after several weeks so that organisms cannot track along the catheter from the skin into the circulation.
+
-
Some long-term single lumen CVCs are available with a small volume chamber attached to the extravenous end of the catheter (Portacath, Infusaport). The chamber is implanted subcutaneously after the vein is catheterised and can be accessed for chemotherapy or blood sampling by inserting a needle into it through the skin.  
+
CVC insertion is best performed in an operating theatre, under local or general anaesthesia, and with ultrasound localisation of the central vein. The patient is placed in a supine, slightly head-down position, and the surface anatomy of the vein is marked. Aseptic technique is essential. A hollow wide-bore needle is inserted into the vein, a guidewire is passed down the needle and the needle is removed. The guidewire position is checked radiologically. A plastic dilator is passed over the guidewire to dilate a track for the catheter and is removed, and the CVC is passed over the guide wire which is removed after the CVC is in place. A chest X-ray is performed to check the final position of the CVC and also to ensure that a pneumo- or haemothorax has not occurred due to inadvertent puncture of the pleura or lung. The catheter is sutured to the skin to prevent dislodgement and the exit site is dressed with an adhesive dressing.
-
CVC insertion is best performed in an operating theatre, under local or general anaesthesia, and with ultrasound localisation of the central vein. The patient is placed in a supine, slightly head-down position, and the surface anatomy of the vein is marked. Aseptic technique is essential. A hollow wide-bore needle is inserted into the vein, a guidewire is passed down the needle and the needle is removed. The guidewire position is checked radiologically. A plastic dilator is passed over the guidewire to dilate a track for the catheter and is removed, and the CVC is passed over the guide wire which is removed after the CVC is in place. A chest X-ray is performed to check the final position of the CVC and also to ensure that a pneumo- or haemothorax has not occurred due to inadvertent puncture of the pleura or lung. The catheter is sutured to the skin to prevent dislodgement and the exit site is dressed with an adhesive dressing.
+
==Further reading==
-
== Further reading ==
+
Keen G, Farndon JR, eds. ''Operative Surgery and Management''. 3rd ed. Oxford: Butterworth-Heinemann; 1994.
-
Keen G, Farndon JR, eds. ''Operative Surgery and Management''. 3rd ed. Oxford: Butterworth-Heinemann; 1994.
+
==MCQs==
-
== MCQs ==
+
''Select the single correct answer to each question.''
-
''Select the single correct answer to each question.''
+
# Universal precautions:
 +
## protect operating theatre staff from electric shocks
 +
## prevent polluted air from entering the operating theatre
 +
## <div class="correct-answer">impose a physical barrier between patients and carers</div>
 +
## are only to be used when operating on patients
 +
## protect only against bacterial pathogens
 +
# Endoscopic surgery:
 +
## has a very limited role in general surgical practice
 +
## is inherently unsafe because the surgeon cannot touch the structures being operated on
 +
## is associated with greater post-operative pain and immobility
 +
## <div class="correct-answer">enables cholecystectomy to be performed as day case surgery in some patients</div>
 +
## can only be used for part of an operation
 +
# Sutures:
 +
## should be left in the skin for a minimum of 2 weeks
 +
## often need to be removed with local anaesthetic
 +
## must be tied tightly so that arterial inflow into tissues is not possible
 +
## <div class="correct-answer">made of catgut lose tensile strength within 3 weeks</div>
 +
## of all types must eventually be removed
 +
# Surgical drains:
 +
## <div class="correct-answer">are removed when they are no longer necessary</div>
 +
## should always be removed the day after surgery
 +
## are removed under general anaesthesia
 +
## are not necessary with modern surgical techniques
 +
## are required after the majority of general surgery procedures
-
#Universal precautions:
 
-
##protect operating theatre staff from electric shocks
 
-
##prevent polluted air from entering the operating theatre
 
-
##<div class="correct-answer">impose a physical barrier between patients and carers</div>
 
-
##are only to be used when operating on patients
 
-
##protect only against bacterial pathogens
 
-
#Endoscopic surgery:
 
-
##has a very limited role in general surgical practice
 
-
##is inherently unsafe because the surgeon cannot touch the structures being operated on
 
-
##is associated with greater post-operative pain and immobility
 
-
##<div class="correct-answer">enables cholecystectomy to be performed as day case surgery in some patients</div>
 
-
##can only be used for part of an operation
 
-
#Sutures:
 
-
##should be left in the skin for a minimum of 2 weeks
 
-
##often need to be removed with local anaesthetic
 
-
##must be tied tightly so that arterial inflow into tissues is not possible
 
-
##<div class="correct-answer">made of catgut lose tensile strength within 3 weeks</div>
 
-
##of all types must eventually be removed
 
-
#Surgical drains:
 
-
##<div class="correct-answer">are removed when they are no longer necessary</div>
 
-
##should always be removed the day after surgery
 
-
##are removed under general anaesthesia
 
-
##are not necessary with modern surgical techniques
 
-
##are required after the majority of general surgery procedures
 
</div>
</div>

Revision as of 16:06, 22 March 2011

Contents

Introduction

This chapter reviews techniques used in surgical practice and invasive procedures.

The operating room

The operating room is a dedicated area for surgical procedures and must be conducive to performing surgery to the highest standards of safety for patients and staff. The principal purpose of such a dedicated area is to reduce the risk of infection of patients. The operating room must be large enough for complex procedures to be undertaken, for storage of appropriate equipment, movement of staff, as well as the maintenance of a sterile area around the operative field. By changing the operating room air 20–25 times each hour at positive pressure relative to outside the room, low concentrations of airborne bacteria and particulate matter can be maintained. The number of people in the room and their movement should be minimised. Ambience should be calm and professional, and the air temperature such that inadvertent patient hypothermia does not occur. The operative field must be well illuminated by direct bright light, and surgeons sometimes wear a head light for procedures in body cavities which cannot be illuminated easily by standard operating room lights.

The surgeon's assistant has the important role of assisting and supporting the surgeon in the smooth conduct of operations. It is important to concentrate on the task at hand, to carry out the surgeon's instructions with speed and accuracy, to have a sense of anticipation, and to notify the surgeon of any potential hazard during the operation.

A face mask which covers the nose and mouth prevents droplet spread of bacteria, is worn for any invasive procedure and is changed after each case. Eye protection in the form of plain plastic glasses or a visor attached to the face mask must be worn to protect against droplet spray of infected body fluids. Gloves are worn if there is a possibility of coming into contact with patients' body fluids. Clean theatre attire, dedicated theatre shoes, and a disposable hair cover are worn while in the operating suite.

Aseptic techniques

Aseptic techniques are clinical practices which aim to prevent infection occuring in the patient as a result of the surgical procedure by:

  • Preparation and cleaning the patient's skin with antiseptic fluid before it is cut or punctured.
  • Use of sterilised instruments, equipment or surgical materials which might come into contact with the operative field and surgical wound.

Personnel involved directly in the operative procedure (surgeon, surgical assistant and ‘scrub’ nurse) wash their hands and forearms with antiseptic soap for 5 minutes before the first operation of the day and for 3 minutes before each subsequent case to reduce skin flora. Hands are dried with sterile towels, and a moisture-impermeable sterile gown is worn. One or two pairs of sterile gloves prevent transfer of bacteria from the surgeon's hands to the patient and also protect the surgeon from infected blood and body fluids from the patient.

The patient should shower or bathe with an antiseptic soap before going to the operating room. After induction of anaesthesia, hair is removed from the operative site by shaving with a razor or electric clippers. The skin is cleansed with an antiseptic solution starting at the site where the incision will be made and working away from the area, so that approximately 10–20 cm of skin around the incision site is prepared. The patient is covered with sterile linen or impermeable drapes, leaving exposed only the cleansed area around the incision site, which may be covered by a sterile adhesive plastic drape.

Surgical antiseptics

The commonest source of bacterial contamination in the operating room is from the patient. Therefore, topical antiseptic agents are used to reduce the number of skin organisms prior to any skin incision or puncture, and include:

  • Aqueous chlorhexidine (0.5%) is used to disinfect mucous membranes and parts of the body adjacent to structures which would be adversely affected by more stringent antiseptics (e.g. the skin around the eyes). Aqueous chlorhexidine is bactericidal and has low tissue toxicity.
  • Cetrimide (2%) is bactericidal.
  • Iodine-based antiseptics (e.g. povidone iodine (10%) [Betadine], alcoholic iodine solution) destroy a wide range of bacteria, especially staphylococci, by iodisation of microbial proteins.
  • Alcohol-based (70%) antiseptics kill bacteria by evaporation.

Sterility

Anything that comes into contact with the surgical wound must be sterile. The method of sterilisation depends on the item being sterilised (Methods of sterilisation).

Universal precautions

The risk of transmission of infectious agents from patients to staff (and vice versa) is reduced by practising universal precautions. Thus, it is assumed that all patients harbour potentially dangerous pathogens (e.g. hepatitis C, HIV) no matter how innocuous they appear, because carrier status cannot definitely be excluded without repeated, expensive and time consuming investigations. The principle of universal precautions is to establish a physical barrier between the patient and the carer to prevent direct contact with any potentially infected body fluid or tissue in either direction (Universal precautions).

Hazards

In addition to infection, there are many potential sources of hazard in the operating environment. Hazards, other than those intrinsic to the anaesthetic and surgical operation, are organisational, or related to operating room equipment or the transfer and positioning of the patient on the operating table.

Organisational hazards

Organisational hazards should be entirely preventable. A full history and examination of the patient must be made before surgery, including the past medical history, drug history and allergies, so that elementary errors are not made (e.g. unwittingly operating on a patient with a pacemaker or who is anticoagulated, or prescribing a drug to which the patient is allergic). Before surgery commences, the reason for and nature of the operation, together with its potential common and serious complications, and the reasonable expectations from the procedure, are discussed with the patient and family who are free to ask any questions. A consent or request for treatment form, which states the nature of the operation and the side on which the operation is to be performed if the operation is a unilateral procedure, is signed by the patient and the surgeon or deputy.

Once in the operating suite, a check is made that the patient is the correct one for that procedure, that the correct side or limb is identified and marked with an indelible pen, and that the lesion or lump is similarly marked to ensure that there is no confusion after the patient has been anaesthetised. All relevant case notes, investigation results and X-rays must be available in the operating room.

Equipment

Diathermy is used universally in surgical practice. High frequency alternating current passes from a small point of contact (active electrode) through the patient to a large contact site (indifferent electrode or diathermy plate) to produce localised heat which coagulates protein. Diathermy produces either (a) coagulation - haemostasis with a small amount of adjacent tissue damage, (b) cutting - tissue cutting with minimal tissue damage, or (c) fulgaration - haemostatsis with considerable tissue necrosis. Potential hazards include electrocution, inadvertent burn to the patient at a remote site and to the surgeon, fire associated with pooled alcohol-based antiseptics, explosion of flammable anaesthetic gases, and interference with the function of cardiac pacemakers.

A variety of lasers with different wavelengths and effects on cells and tissues are used in surgical practice for highly accurate tissue destruction (e.g. mucosal surgery, CNS tumours, dermatological lesions, aerodigestive tumours), coagulating blood vessels (e.g. gastrointestinal tract, retinal photocoagulation), and for photo-activation of intra-tumour haematoporphyrin for malignant tumour destruction (photodynamic therapy). Hazards include eye damage, explosion of anaesthetic gases, and shattering and destruction of other equipment.

Limb torniquets are used to provide a blood-less field in which to operate. The limb is elevated and exsanguinated by a rubber bandage or compressive sleeve, and the proximal torniquet inflated to 50 mm Hg (upper limb) or 100 mm Hg (lower limb) above systolic blood pressure. A torniquet should not be kept inflated for more than 60-90 minutes. Hazards include arterial thrombosis, distal ischaemia, nerve compression and skin traction.

Positioning of the patient

The patient is positioned on the operating table in such a way that the procedure is facilitated and the airway can be protected. Pressure points are padded, and limbs are positioned so that peripheral nerves, major blood vessels, joints and ligaments are not stretched or compressed. The anaesthetised patient must be in a stable position on the operating table and may need to be strapped on with broad adhesive tape. There must be no contact between the skin and any metallic surface because of the risk of diathermy burn and pressure necrosis. Sections of the operating table can be angled so that the patient is optimally positioned for the particular procedure (e.g. flexed while lying supine or on one side, head-down, head-up).

Endoscopy

Endoscopy is performed by inserting a fibre-optic telescope containing a light source and instrument channels into the gastrointestinal, respiratory and urinary tracts. The operator undertakes the procedure by manipulating the endoscope while viewing a video screen or looking down the eye piece of the instrument.

Gastrointestinal endoscopy

Endoscopy of the gastrointestinal tract allows the endoscopist to view the lumen of the oesophagus, stomach and proximal half of the duodenum (oesophagogastroduodenoscopy), colon (colonoscopy), and rectum and distal sigmod colon (sigmoidoscopy), and distal rectum and anal canal (proctoscopy). It is usually performed under sedation. Intestinal endoscopy can also be performed at laparotomy (enteroscopy) by making a small incision in the intestine and the surgeon passes the endoscope along the intestinal lumen. Procedures, such as dilatation of strictures, biospy and diathermy ablation of polyps, injection of adrenaline around bleeding gastric and duodenal ulcers, cholangio-pancreatography, removal of common bile duct calculi, injection of haemorrhoids, and tumour phototherapy can be performed using fibreoptic endoscopes.

Bronchoscopy

The upper airway, trachea and proximal bronchi can be inspected by bronchoscopy, which may be performed under local or general anaesthesia. Bronchoscopy is used for diagnosis (e.g. inspection and biopsy of lung tumours) or therapy (e.g. removal of foreign bodies, aspiration of secretions). Anaesthetists ocassionally use the fibre-optic bronchoscope to facilitate difficult endotracheal intubation. (see also Common topics in thoracic surgery).

Urological endoscopy

The urethra (urethroscopy), bladder (cystoscopy), and ureters (ureteroscopy) can be inspected for diagnostic purposes. Extensive therapeutic procedures (e.g. resection of the prostate, diathermy and excision of bladder tumours, extraction of calculi) can be performed safely with far less morbidity than the equivalent open procedures.

Endoscopic surgery

Endoscopic surgery is performed by inserting a microchip video camera with a light source and specially crafted long-handled surgical instruments into a body cavity by way of small incisions. The surgeon undertakes the procedure by manipulating the instruments while viewing a video screen.

The advantages of endoscopic or ‘closed’ surgery are reduced post-operative pain and analgesic requirements, earlier discharge from hospital, and earlier return to normal function. However, many surgical procedures either cannot be undertaken endoscopically because of their very nature, or cannot be completed endoscopically because of difficulty or patient safety, in which case the operation is converted to an ‘open’ procedure. Some procedures use endoscopic techniques to assist with the procedure and an incision is made to either complete the operation or deliver the resected specimen (e.g. bowel resection, nephrectomy, splenectomy). The range of endoscopically performed operations in many surgical specialties has increased enormously over the last 10–15 years.

Abdominal surgery

Laparoscopy refers to the technique of insufflating the peritoneal cavity with gas, inserting a camera through a 10–15-mm sub-umbilical incision and inspecting the abdominal contents. Usually, three additional ports are inserted through 5–10-mm incisions in the abdominal wall and instruments (e.g. scissors, grasping devices, retractors, staplers, needle holders) are introduced and manipulated by the surgeon to perform the operation. Procedures such as cholecystectomy, gastric fundoplication, hiatus hernia repair, division of adhesions, appendicectomy, splenectomy, adrenalectomy, nephrectomy, oophorectomy, tubal ligation, and hernia repair can be undertaken laparoscopically with less morbidity than if undertaken as an open or conventional operation. Endoscopic surgery has allowed some procedures to be undertaken as day cases, whereas the same procedure performed as an open operation would require an inpatient stay of several days (e.g. cholecystectomy, hernia repair).

Thoracic surgery

Thorascopy involves inserting a camera with a light source and instruments into the thoracic cavity. The technique is used diagnostically and therapeutically for procedures such as drainage of the thoracic cavity (haemothorax, pleural effusion and empyema), lung biopsy, pleurodesis, and excision of lung bullae. The mediastinum can be inspected and mediastinal lymph nodes can be biopsied by mediastinoscopy, which may prevent the need for an exploratory thoracotomy.

Orthopaedic surgery

Large joints (e.g. knee, hip, ankle, shoulder, wrist) can be inspected by arthroscopy. Therapeutic procedures include removal of bone chips, cartilage excision and removal, and ligament repair. Arthroscopic surgery has been enormously beneficial for orthopaedic patients and has allowed far more rapid return to function.

Open surgery

Open surgery is the traditional or conventional method of operating. In general terms, open surgery involves making a surgical wound, dissecting tissues to gain access to and mobility of the structure or organ of interest, completing the therapeutic procedure, ensuring haemostasis is complete, and then closing the wound with sutures. Open surgey is performed more with the hands and direct touch than endoscopic procedures, and fingers may be used for ‘blunt’ dissection. The surgical wound accounts for much of the morbidity of open surgery, particularly the cutting of muscle. The range of open operations is extremely wide, as evidenced by the procedures described throughout this book.

Surgical methods

Surgical operations are performed by well worked out, standardised steps which progress in logical sequence. An operative plan is worked out by the surgeon for every operation.

Surgical instruments

There are literally thousands of surgical instruments, some simple and others extremely complex, but each designed for a specific function. The surgical incison is made with a scalpel which consists of a re-usable handle and a disposable blade. Scissors are used to cut other tissues and sutures, and for blunt dissection with the blades closed. Diathermy is used for haemostasis and to cut through tissue layers beneath the skin. Tissues are held with dissecting or tissue grasping forceps rather than the fingers. Hand-held forceps either have teeth which tend to dig into and damage tissues, or are non-toothed with poorer grasping ability. Needle holders are used to grasp needles for suturing and eliminate the need for hand-held needles, and are therefore safer. They have a ratchet so that the needle can be contained securely in the holder while not in the surgeon's hand. Retractors allow the surgeon to operate in an adequately exposed field. Self-retaining retractors keep the wound edges apart without the aid of an assistant. Retractors held by the assistant provide tissue retraction in awkward parts of the wound and in situations where retraction of specific tissues is required so that intricate parts of the operation can be performed. A sucker is used to aspirate blood and body fluids from the operative field and to remove smoke created by the diathermy. There are many instruments designed specifically for surgical specialties and procedures.

Incisions

Surgical incisions are made so that:

  • The operation can be undertaken with adequate exposure of the area or structure of interest.
  • The procedure can be performed and completed safely and expeditiously.
  • The wound heals satisfactorily with a cosmetically acceptable scar.

Thus, incisions are to be of adequate but not excessive length and, if possible, placed in skin creases, particularly when operating on exposed areas of the body such as the face, neck and breast. Parallel skin incisions (tram tracking) and V- or T-shaped incisions are avoided because of ischaemia of intervening tissue and pointed flaps.

Tissue dissection

Ideally, surgical dissection should be performed along tissue planes which tend to be relatively avascular. The aim is to isolate (mobilise) the structure(s) of interest from surrounding connective tissue and other structures with the least amount of trauma and bleeding. Tissues should be handled with great care and respect and as little as possible. Dissection is undertaken by using a scalpel or scissor (sharp dissection), a finger, closed scissor, gauze pledget, or scalpel handle (blunt dissection), or the diathermy. Gentle counter traction on tissues by the assistant facilitates the dissection.

Haemostasis

Surgical haemostasis refers to stopping bleeding which occurs with transection of blood vessels. The majority of cases of operative and post-operative bleeding are due to inadequate surgical haemostasis rather than disorders of clotting and coagulation. Haemostasis is essential in order to prevent blood loss during surgery and haematoma formation post-operatively. Methods of surgical haemostasis include:

  • Application of a haemostatic clamp to a blood vessel and then ligation with a surgical ligature (see Care of the critically ill patient).
  • Suture ligation of a vessel - under-running a bleeding vessel with a figure-of-8 suture which is tied firmly.
  • Diathermy coagulation (see Anaesthesia and pain management).
  • Localised pressure for several minutes to allow coagulation to occur naturally.
  • Application of surgical materials (e.g. oxidised cellulose, Surgicell) which promote coagulation.
  • Application of topical agents to promote vasoconstriction (e.g. adrenaline) or coagulation (e.g. thrombin).
  • Packing of a bleeding cavity with gauze packs as a temporary measure until definitive haemostasis can be achieved.

Sutures

Sutures have been used to close surgical wounds for thousands of years, and initially were made from human or animal hair, animal sinews, and plant material. Today, a wide variety of material is available for suturing and ligating tissues (Sutures).

Sutures are selected for use according to the required function. For example, arteries are sutured together with non-absorbable polypropylene or polytetrafluoroethylene (PTFE) sutures which are nonthrombogenic, cause virtually no tissue reaction, and maintain their instrinsic strength indefinitely so that the anastomotic scar (which is under constant arterial pressure) does not stretch and become aneurysmal. Skin wounds, for example, are sutured with either non-absorbable sutures, which are removed after several days (see Care of the critically ill patient), or absorbable sutures hidden within the skin (subcuticular sutures) and which are not removed surgically but are absorbed after several weeks.

Sutures are available in diameters ranging from 0.02–0.50 mm. The minimum calibre of suture should be used, compatible with its function. Non-absorbable sutures are avoided for suturing the luminal aspects of the gastrointestinal and urinary tracts because substances within the contained fluids (e.g. bile, urine) may precipitate on persisting sutures and produce calculi.

The requirements of suture material are:

  • Tensile strength - the suture must be strong enough to hold tissues in apposition for as long as required.
  • Durability - the suture must remain until either healing is advanced or indefinitely if the healed tissue is under constant pressure.
  • Reactivity - tissue reaction (i.e. an inflammatory response) allows absorbable sutures to be removed by phagocytosis but results in chronic inflammation if non-absorbable sutures remain in situ.
  • Handling characteristics - sutures must be easy to grasp, handle and tie.
  • Knot security - sutures must be able to be tied effectively so that knots do not come undone or slip. Sutures are classified as:
  • Absorbable or non-absorbable. The rate of absorption of absorbable sutures depends on what they are made of and their thickness. Disappearance of the suture occurs through inflammatory reaction, hydrolysis or enzymatic degradation.
  • Synthetic or natural material. Sutures of natural (animal) origin are being phased out of surgical practice because of the very minimal risk of disease transmission. A wide variety of synthetic suture materials are available.
  • Monofilament or multifilament. Monofilament sutures pass through tissues easily, are generally less reactive, and are more difficult to handle and knot securely. Multifilament sutures are braided or twisted thread, and are easier to handle and knot, but are more likely to harbour micro-organisms within the suture.

Surgical knots

Knots are tied to ensure that ligatures and sutures remain in place and do not slip or unravel. The ability to tie a secure knot is a fundamental technique in surgery, and patients' lives literally depend on knot security (e.g. the knot in a ligature used to tie off an artery). Knot security depends on friction between the throws of the ligature material, the number of throws used to tie the knot, the strength of the ligature material, and the tightness of the knot. Usually, multiple throws are used to secure the knot (e.g. two reef knots, one on the other).

Suturing

The technique of suturing depends on the tissue and wound being sutured. Sutures may be either continuous (e.g. subcuticular skin sutures, abdominal closure, vascular anastomosis), or interrupted (e.g. skin sutures, sternal wires). The function of sutures is to hold the adjacent edges of sutured tissues in apposition and to immobilise them in that position so that wound healing (i.e. neovascularisation, connective tissue ingrowth and collagen formation) is facilitated. It is essential that sutures are not tied so tightly that the tissues encompassed by them become ischaemic. Skin sutures may be supported by adhesive paper tapes.

Retention sutures (incorrectly referred to as tension sutures) are used to close abdominal incisions which are thought to be at increased risk of dehiscence, and are inserted to encompass a large amount of fascial tissue and are placed 3–5 cm apart.

Within the last two decades, stainless steel staples have been used to close skin wounds and to perform gastrointestinal anastomoses. Staples are quicker to use than sutures, but are relatively expensive and produce a worse cosmetic result for skin closure than subcuticular absorbable sutures.

Suture removal

Sutures are removed as early as possible to minimise the risk of infection and scarring, so long as tissue healing is sufficently advanced that the wound will not open when the sutures are removed. Sutures are therefore removed at different times, depending on tissue and general patient factors (Timing of suture removal). for example, sutures are left in situ for a longer time in patients who are immunosuppressed, malnourished, jaundiced, or undergoing chemotherapy; who have renal failure, and in tissues judged to be relatively ischaemic, subject to increased stress and tension, and which have been irradiated.

Surgical drains

Drains are used widely in surgical practice to

  • Remove blood or serous fluid, which would otherwise accumulate in the operative area (e.g. wound drain).
  • Provide a track or line of minimal resistance so that potentially harmful fluids can drain away from a particular site (e.g. drain placed into an intra-abdominal abscess cavity).

Several different methods of drainage may be used depending on the required function.

  • Open drainage - a drain tube or strip of soft flexible latex rubber is placed so secretions or pus can drain along the track of the drain into gauze or other dressing covering the external end of the drain tube (e.g. drain placed in an abscess cavity, drain placed prohylactically near a bowel anastomosis in case of subsequent anastomotic leak).
  • Closed drainage - a tube is placed into an area or viscus to drain fluid contents into a collecting bag so that there is no contamination of the drained area from outside the system (e.g. chest drain, urinary catheter, cholecystostomy drain).
  • Closed suction drain - the drain tube is connected to a bottle at negative atmospheric pressure so that fluid is sucked out of the area (e.g. wound drain, drain under skin flaps).

It is important to note both the amount and the type of fluid which drains. Large volumes of fluid drainage may need to be replaced as intravenous fluids (e.g. duo-denal fistula fluid). Depending on the particular situation, it may be necessary to culture drain fluid or send it for estimation of haemoglobin, creatinine, electrolytes, amylase or protein. A radiological contrast study may be performed along the drain tube, for example to estimate the size of a cavity being drained.

Drain tubes are removed when they are no longer required, for example when there is minimal fluid being drained, or when a cavity being drained has contracted and is small. Drains are removed simply by cutting the suture which anchors them to the skin and withdrawing the tube from the patient.

Venepuncture

Venepuncture involves removing blood from a superficial vein, usually in the antecubital fossa or dorsum of the hand, by inserting a needle attached to a syringe or collection tube at negative pressure (vacutainer system). A venous torniquet is applied around the arm, which is hung in a dependent position; the patient vigorously opens and closes the hand, and the vein is gently patted to encourage venous dilatation. The skin is cleansed with antiseptic and the needle is inserted through the skin into the dilated vein at an angle of 30–45 degrees. Only the required volume is aspirated, the torniquet is released, the needle is withdrawn, the puncture site is immediately covered with a cotton wool swab, and light pressure is applied for 1–2 minutes. The site is covered with an adhesive dressing. Complications include bruising, haematoma, and rarely, infection and damage to deeper structures. Inadvertent needlestick injury to the venepuncturist is avoided by careful technique.

Intravenous cannulation

Intravenous (i.v.) cannulation is used commonly for administration of fluids and drugs. Superficial veins on the forearms and dorsum of the hands are used for i.v. cannulation. Antecubital fossa veins are best avoided for cannulation because the elbow has to be kept extended to avoid kinking of the cannula. Leg veins may have to be used in the absence of useable upper limb veins. Cannulas have a soft outer Teflon sheath attached to a hub, and a central hollow needle attached to a small chamber.

A suitable vein is identified as for venepuncture. Local anaesthetic cream is applied to the skin overlying the vein or local anaesthetic (1% lignocaine without adrenaline) is injected intradermally next to the vein after cleansing the skin with antiseptic. The cannula (needle and sheath) is inserted through the skin into the vein at an angle of 10–30 degrees and advanced into the vein in the same movement. The needle is removed from the sheath and a closed three-way tap or i.v. giving set is joined to the hub of the sheath. The cannula is secured to the skin with adhesive tape.

Intravenous infusion is painful when the infusate is cold or contains irritants (e.g. potassium, calcium, drugs of low or high pH), or if the cannula pierces the vein wall and fluid extravasates subcutaneously. Thrombophlebitis develops at the insertion site after about three days, and i.v. cannulas should be re-sited if infusions are required for longer periods.

Central venous catheterisation

Percutaneous catheterisation of a central vein is used for

  • Short- or long-term venous access when peripheral veins are unsuitable or cannot be used (e.g. prolonged fluid infusion, total parenteral nutrition, ultrafiltration, haemodialysis, plasma exchange, chemotherapy).
  • Short-term monitoring of central venous pressure A central venous catheter (CVC) may be inserted into the internal or external jugular vein or the subclavian vein. Temporary CVCs are made of semi-rigid Teflon, are approximately 25 cm in length and, depending on their function, are between 1 and 4 mm in diameter and have one, two or three lumens. Long-term CVCs are made of barium-impregnated silastic and are quite flexible. They have a Dacron cuff bonded to the part of the catheter which lies subcutaneously and becomes incorporated by fibrous tissue after several weeks so that organisms cannot track along the catheter from the skin into the circulation.

Some long-term single lumen CVCs are available with a small volume chamber attached to the extravenous end of the catheter (Portacath, Infusaport). The chamber is implanted subcutaneously after the vein is catheterised and can be accessed for chemotherapy or blood sampling by inserting a needle into it through the skin.

CVC insertion is best performed in an operating theatre, under local or general anaesthesia, and with ultrasound localisation of the central vein. The patient is placed in a supine, slightly head-down position, and the surface anatomy of the vein is marked. Aseptic technique is essential. A hollow wide-bore needle is inserted into the vein, a guidewire is passed down the needle and the needle is removed. The guidewire position is checked radiologically. A plastic dilator is passed over the guidewire to dilate a track for the catheter and is removed, and the CVC is passed over the guide wire which is removed after the CVC is in place. A chest X-ray is performed to check the final position of the CVC and also to ensure that a pneumo- or haemothorax has not occurred due to inadvertent puncture of the pleura or lung. The catheter is sutured to the skin to prevent dislodgement and the exit site is dressed with an adhesive dressing.

Further reading

Keen G, Farndon JR, eds. Operative Surgery and Management. 3rd ed. Oxford: Butterworth-Heinemann; 1994.

MCQs

Select the single correct answer to each question.

  1. Universal precautions:
    1. protect operating theatre staff from electric shocks
    2. prevent polluted air from entering the operating theatre
    3. impose a physical barrier between patients and carers
    4. are only to be used when operating on patients
    5. protect only against bacterial pathogens
  2. Endoscopic surgery:
    1. has a very limited role in general surgical practice
    2. is inherently unsafe because the surgeon cannot touch the structures being operated on
    3. is associated with greater post-operative pain and immobility
    4. enables cholecystectomy to be performed as day case surgery in some patients
    5. can only be used for part of an operation
  3. Sutures:
    1. should be left in the skin for a minimum of 2 weeks
    2. often need to be removed with local anaesthetic
    3. must be tied tightly so that arterial inflow into tissues is not possible
    4. made of catgut lose tensile strength within 3 weeks
    5. of all types must eventually be removed
  4. Surgical drains:
    1. are removed when they are no longer necessary
    2. should always be removed the day after surgery
    3. are removed under general anaesthesia
    4. are not necessary with modern surgical techniques
    5. are required after the majority of general surgery procedures
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