THE BASIC SURGERY     |   home
Surgery is an art of working with the hands. It's name derives from the Latin word chirurgia, which in turn comes from the Greek cheiros (hand), and ergon (work). A description of it's concerns was made by the 16th centrury French surgeon Ambroise Pare:
"there are five duties in surgery: to remove what is superfluous, to restore what has been dislocated , to separate what has grown together, to reunite what has been divided and to redress the defects of nature".
The definitions and descriptions of the basic surgical skills act as the foundations for the more advanced surgical procedures and hence will include the following fundamental aspects:

*antiseptic and aseptic methods
*use of surgical instruments and sutures
*control of haemorrhage
*primary care of wounds.

Prior to modern methods the greatest cause of operative surgery "failure" was post-operative infection due to flawed techniques.
The aim of antiseptic and aseptic techniques is to prevent surgical infection and increase the safety and breadth of surgery.
Antisepsis: prevention of infection by inhibiting the growth of infectious agents.
Asepsis: a condition in which living pathogenic organisms are absent.

11.1. Theatre Dress
Appropriate dress reduces the dissemination of organisms from members of the operating team, although it is now also apposite to consider that protection of the team is just as important. Theatre garb is usually of a restful and non-glaring colour - eg. blue or green.
Appropriate theatre dress will include:
* hair cover - paper or glass fibre balaclavas afford the more complete coverage and in some instances may be colour-coded to allow identification.
* mask - usually glass fibre to cover the nose and mouth and now with deflector shields to protect the wearer.
* shirt/trousers or dress - the exposed parts of the legs should be covered.
* shoe cover - paper or linen over comfortable shoes or clogs.
* plastic apron - appropriate for urological or arthroscopic procedures.

11.2. Surgical Hand Scrub
Before commencing the scrub it is wise to ensure that the cap, mask and any accessory (headlight, magnifying loupe) are comfortable and securely adjusted.
Rings should be removed and finger nails short and clean.
An effective scrub requires the use of an antiseptic detergent solution stored in an accessible and functional bottle:
*4% chlorhexidine - "Hibiclens"
*7.5% povidone-iodine - "Betadine"
The scrub bay should be remote from the theatre and the tub of a suitable height and dimension; the taps may be activated by the elbow, foot or light sensor.
Some debate exists as to the most effective method but the following are standard guidelines:
* initial scrub of 5 minutes and subsequent "scrubs" of 2 minutes
* the excessive use of a scrub brush may encourage desquamation and hence is used lightly and at the initial scrub.
The fingers and hands are treated as having four planes and each is scrubbed sequentially from the finger-tips to just below the elbows, keeping the hands elevated to allow water to drain away from the fingers.

11.3. Gowning and Gloving
Towels and gowns are prepacked (sterile) and opened without contamination of the contents. They are usually linen although single-use, waterproof paper gowns are available.
The hands and arms are dried up to a point just below the extremity of the scrub. The surgical gown is folded in such a way that when picked up and allowed to fall open the inside should face the wearer; this surface only being touched by the ungloved hand. The hands are not allowed to protrude through the cuffs in order to facilitate the closed method of gloving - glove powder should be washed off.
The back of the gown should be covered and once gowned and gloved care should be taken to avoid contamination - remember that bacteria penetrate wet gowns.

11.4. Patient Preparation

11.4.i. Shaving
Shaving of the operative field facilitates:
*antiseptic skin preparation
* application of adhesive drapes
* wound closure
* application and removal of dressings.
Recent reviews of pre-operative hair removal techniques:
* clipping should be preferred to shaving
* should not be attended in the OR or anaesthetic bay
* should be performed approximately 2 hours pre-operatively
* should be followed by a shower and shampoo with an antiseptic solution
The area clipped should extend sufficiently wide of the proposed incision to allow flexibility of access.
Post-operative infection rates as high as 7% associated with shaving has been reported.
If shaving is to be performed:
* do not apply soap with a brush
* Hexachlorophane soap should not be used as a prelude to skin preparation with chlorhexidine as the two are antagonistic.

11.4.ii. Skin Preparation
The operative site (all areas exposed by drapes) should be thoroughly washed (and dried)
well beyond the planned incision using an appropriate detergent preparation:
These preparations are usually water based but may be alcoholic.
When using alcohol based preprations:
* avoid the eyes and mucosal surfaces
* avoid pooling as there is a risk of fire when using diathermy.

11.4.iii. Draping
The aim of sterile draping is to isolate the operative field and avoid contamination of this, instruments and members of the operative team.
All drapes should be secured by:
* towel clips
* sutures
* adhesive drapes - help isolate large or irregular operative sites and include a layer of paper or plastic between them and unsterile surfaces.

11.5. Instrument Sterilisation
Instruments brought into contact with a patient must be guaranteed sterilised by one of the following methods:
* heat - pressurised steam, dry heat, formaldehyde
* chemicals - ethylene oxide gas
* ionising radiation - gamma rays.
The choice of method depends upon the material being sterilised.


Ergonomic surgery depends upon the efficiency of:
* instruments
* nursing staff
* surgeon and assistant.
Correct deployment of the operating team makes for safe efficient surgery:
* often the instrument nurse will stand at a higher level than the surgeon to enchance vision and also so that instruments may be passed in a downward direction: ie. the "drop- passage" method.
* ophthalmic and microsurgery are often best performed with the surgeon seated and with the forearms resting on a stable surface.
A number of instruments may be used in varying ways:
* scalpels - "pen" or "table-knife" grip
* scissors - blunt or sharp dissection.

111.1. Suturing

A Little History
Clearcut evidence of stitches in live flesh appears in the classical writings of India, Egypt, Greece and rome but the overall priority for stitching must go to the ants.
Sutures with ant heads are often mentioned in connection with primitive medicine, even to this day and Sushruta (circa 1000BC) describes the following:
".....large black ants should be applied to the perforated intestines and their bodies should be separated from their heads after they had firmly bitten the perforated parts with their claws jaws)....."
The world premiere of a surgical suture in human flesh was placed by an embalmer on the belly of a Twenty-first Dynasty mummy about 100BC.
In the Hippocratic collection sutures are mentioned but only in relation to the nose and eyelids.
Ancient Hindu texts mention a series of exercises in experimental surgery which included a threaded curved needle of triangular section which was used to practice surgical knots on a piece of hide.
Celsus (1st centrury AD, Rome) mentions using the hair of a woman for very fine work such as suturing eyelids. He also used fine metal pins (fibulae) with thread wrapped around to draw wound edges together - indeed Ambroise Pare in 1564 used a threaded needle as a fibula to close a hair lip.
Galen (130-200AD) was able to do better than Hippocrates because he sutured muscle and was probably the first to suture tendon. He also used sutures to tie bleeding vessels.
The earliest suture materials appear to have been cotton, Chinese silk, hemp, linen and plaited horse hair but almost any thread was used.

Modern Suturing
Sutures are used to close wounds by bringing the tissues in contact with one another to permit healing by first intention.
Modern sutures are prepared commercially and sterilised by gamma radiation. The needles are eyeless, with the end shaped as a tube into which the suture is swaged. These "atraumatic" sutures pass through tissue with minimal effort and damage.

111.1.i. Suture Materials
Sutures may be either:
* absorbable or non-absorbable
* monofilament or braided
In general non-absorbable materials excite little tissue reaction but because they are not destroyed are only used where they are deeply buried (for permanent support) or removable. Braided materials tend to be more flexible and easy to knot whereas monofilament synthetics have an inherent springiness.
The gauge of suture material - expressed in BP or metric sizes - chosen is dependent upon the tissue to be sewn:
* 3/O (metric 3) gut is thicker than 6/O (metric 1).
Knots may be tied by hand or with instruments with reef or surgeon's knots used.

111.1.ii. Suture Needles
Suture needles are made of stainless steel, may be straight or have varying degrees of curvature expressed as degrees of the arc of a circle (eg. 1/2, 3/8, 5/8.), and be of varying lengths.
The more curved a needle the less rotatory movement required to pass it through tissue: a principle applied if access is a problem.
Suture needles vary in cross-sectional shape and may be ribbed longitudinally to aid stability in the needle holder:
* cutting edge - skin or tendon
* reverse cutting - as above but less traumatic
* non-cutting (round or taper point) - bowel or blood vessel
* taper cutting - dense tissue (aponeurosis, tendon).

Bleeding may be controlled by:
* vasoconstrictors
* coagulation diathermy
* compression
* haemostat
* ligature
* haemostatic agents.
None of the above should replace the need for careful dissection
* arterial bleeding: bright, pulsatile and at high pressure and controlled by direct pressure and vessel clamping with ultimate control by ligature or vascular repair.
* venous bleeding: constant, dark and at low pressure welling up from a wound controlled by elevation, compression and ligation.
* capillary bleeding: constant and bright pink, oozing from exposed surfaces, usually responding to compression and cautery.
A suitable vasoconstrictor injected into and around the operative site preoperatively will aid haemorrhage control. Their pharmacological effect on the rest of the body should not be overlooked.
Examples of vasoconstrictors are: adrenalin, ornipressin (POR8) which may also be mixed with local anaesthetic solutions to aid in post-operative pain control.
Coagulation Diathermy
The use of diathermy is potentially dangerous and electrical safety codes within the theatre should be well known. Correct assembly and connection of both electrodes along with tip protection are essential.

A suitable size should be used and applied to the bleeding vessel in such a way as to allow correct presentation of the tip to the surgeon to allow the use of diathermy or placement of a ligature.

A ligature is basically a suture thread and may be either a "stitch tie" or a "free tie"; resorbable (catgut) or non-resorbable (silk).

Hemostatic Agents
These agents, generally placed in a wound aid in the coagulation process and in particular provide a lattice for platelet aggregation. Examples include oxidised cellulose, which may be enhanced by adding topical thrombin, and bone wax.

Some More History!
The problem of haemorrhage was mastered even later than suturing and mankind had great difficulty discovering the main facts about bleeding. The most effective means by which primitive people stopped bleeding was cautery and this may have been used as early as 3000BC - but wounds of major vessels meant almost certain death. Even the Greeks had only vague notions about haemostasis and if Hippocrates ever tied a vessel he never said so. The ancient Hindu physicians also knew nothing of tying off a vessel. By the time a tourniquet was well-recognised - accredited to Ambroise Pare in the mid 1500's - people were firing guns!
A concept as simple as turning off a tap was not so simple. firstly, there is no turning off a tap for people who have never seen a tap. Secondly, with a major wound the wound itself was often lethal and the bleeding incidental. Thirdly, stopping the flow of outward blood may not help if internal bleeding continues.
The Egyptian and Greek literature both record the use of songs or charms in an attempt to quell bleeding - there are no reports as to the success rate!

As translated in the Smith papyrus (circa 2000BC) the world's first recorded haemostasis was achieved by burning. In the writings of Sushruta (circa 400BC) hot oils were often used to stop bleeding. Pliny talks of a juice of a plant called ephedron which when used "stanches bleeding and cures cough". Similarities with ephedrine!
Celsus describes precisely the use of vinegar on wounds to stop bleeding but more importantly for "....veins that are pouring out blood are to be seized, and round the wounded spot they are to be tied in two places and cut across in between so that each end may retract on itself and yet have it's orifice closed". When circumstance did not allow tying he says that a bleeding vein "....can be burnt with a red-hot iron".
Galen's first aid in case of haemorrhage was to raise the injured part, put a finger into the wound, find the gaping vessels and compress them gently. If this failed he would grasp the bleeder with a hook and twist it around. The last step was to tie the vessels. Galen also relied heavily on "styptics", the best of which he used with perfect safety on a wound exposing the meninges! The Romans still did not use tourniquets to stop bleeding and even argued against them a they would cause blood to squirt out much the same way as ".... if you tie a rope around a skin bag and tighten it !"
In many places, the belief that spider webs help to stop bleeding arose very early and continued for a long time. Shakespeare refers to this in A Midsummer Night's Dream (Act III/I), and indeed little boxes containing spider webs belonged to every soldier's field equipment at the Battle of Crecy in 1346.
Other methods of blood-stanching were tried throughout the ages: hot stones, glowing-red needles, and direct burning with torch or firewood. Tibetan monks poured a mixture of sulphur and saltpetre onto wounds and set it alight. Such a precedent for haemostasis survived well into the 18th Centry when gunpowder was set off in stumps.

Little wonder that hemorrhage is still one of the greatest hindrances to successful surgery.

Wounds are open injuries to tissue with their severity depending on the extent of penetration, disruption and bacterial contamination.

V.1. Classification of Wounds

Wounds may be classified as:
*Clean: elective surgical procedures in a clean field.
*Contaminated: all non-surgical wounds, surgical wounds involving the GIT and wounds with access to infected foci.
i. tidy: sharply incised or penetrating injuries and some low velocity wounds with bacterial contamination being minimal and of short duration with tissue damage restricted to the wound path - eg. slicing finger with a knife.
ii. untidy: caused by serious disrupting forces or by perforation of contaminated viscera with damage being wide and ragged - eg. high velocity missile causing cavitation, or crush injury.
*Infected: wounds infected by bacterial contamination alone or in conjunction with local factors such as necrotic tissue, or excessive tension.
Another method of classifying wounds indicates the possible complications:
* by degree of bacterial contamination - clean, contaminated, infected.
* by mechanism of injury.

V.2. Wound Debridement
Debridement refers specifically to opening up a wound and not to debris.
The aim of debridgement is to convert a contaminated wound into a state analogous with a clean wound and hence produce a scar that is cosmetic and functional.
The contaminated wound should be thoroughly explored and enlarged far enough to determine the extent of damage:
* excise all netrotic soft tissue back to healthy bleeding tissue
* remove bone fragments devoid of periosteum
* irrigate the wound with warm saline to remove blood clots and foreign matter
* decide whether to close primarily or to delay
* administer systemic antibiotics.
The classical example is the gunshot wound.
The use of antibiotics should not lull the operator into a false sense of security or detract from the correct and thorough debridement of a contaminated wound.


V1.1 Insertion of Intravenous Drips
The aim of this procedure is to establish an intravenous access for the administration of fluids, blood or medications.
The materials required include:
* IV fluid
* connecting tubing
* tourniquet
* alcohol swab
* intravenous cannulae
* antiseptic ointment, dressing and tape.

The types of cannulae available include:
* winged butterfly (scalp/vein) needles are used in small peripheral veins and typically for short periods and small volumes of fluid
* plastic cannula over a needle (eg. Angiocath, Jelco) is ideal for rapid infusion and is the most commonly used
* plastic cannula through a needle is usually too small for massive infusion but is longer and therefore suitable for CVP measurement being less easily dislodged.
There are two techniques for the insertion of IV drips:

VI.1.i. Open Technique
This is usually reserved for massive and rapid transfusions as very rapid rates of infusion are possible.
A short, large bore cannula is inserted into a large vein such as the cephalic, basilic or external jugular.
Additional requirements include an excternal pressure cuff, manometer, filter and inline pump.

VI.1.ii. Percutaneous Technique
This technique is suitable for all but the most massive infusion of fluid and is typically used during general anaesthesia.

General Principles
* Attach the IV tubing to the solution and flush the air out
* The upper non-dominant extremity is the site of choice for an IV but avoid veins that
cross a joint space
* Apply a tourniquet above the IV site, assist in venous dilatation and carefully clean the site with an antiseptic swab
* Stabilise the vein distally with the thumb of your free hand and enter the vein either along the side at about 20o or directly - blood should appear in the "flash chamber". Carefully withdraw the needle as the catheter is advanced in the vein
*Remove the tourniquet and attach the IV line - compress the vein with your thumb just
proximal of the catheter to minimise blood loss
* Run the IV fluid and observe for swelling or induration
* Tape the IV securely and apply an antiseptic or antibiotic ointment and a serile dressing - an armboard may help maintain the IV site.

VI.2. Central Venous Cannulation
A central venous cannula is one which is introduced into the superior or inferior vena cava or one of their main branches.

* administration of fluids and medications especially when there is no peripheral access
* administration of hyperalimentation solutions or other fluids that are hypertonic and damage vein walls
* measurement of CVP
* insertion of pulmonary artery catheter or intravenous pacemaker

* prepackaged central venous catheter insertion kit
* cap, mask, gown and gloves
* IV fluid and tubing

The two most common approaches are via the internal jugular or subclavian veins with the safest technique being a modification of the Seldinger technique that utilises an initial placement of a guidewire into the vessel.

Important Points of Technique
* Trendelenburg position to distend veins and reduce risk of air embolus
* following venepuncture the cannula is threaded within or around the needle into the vein
* silastic cannula for prolonged periods and a technique allowing complete removal of the needle (eg. Seldinger guide wire)
* confirm the correct position of the cannula
- free aspiration of blood
- erect chest X-ray
* reliable measurement of CVP requires correct positioning of the cannula and an unimpeded lumen.

puncture of external jugular vein
puncture of internal jugular vein

puncture of susclavian vein
Routes for central venous cannulation include:

Internal jugular vein
Subclavian vein
Femoral vein
External jugular vein
Antecubital veins

* pneumothorax, haemothorax, hydrothorax - listen to the chest and take a chest X-ray after insertion of the deep line
* arterial puncture with haematoma - be cautious in attempting an internal jugular punture on the opposite side after entering an artery
* catheter tip embolus - never withdraw the catheter through the needle as the tip may shear off
* air embolus - place patient head down and on left side to keep air in right atrium.

Factors which determine the choice of central vein

How long will the catheter be required? ie. long term / intermediate / short term Suitability of the vein for technique chosen e.g. for CVP measurement the tip of the catheter must be within the thorax. A femoral route therefore needs a long catheter

Operator: Knowledge and practical experience of the technique -it is be better to have a few clinicians in each area who perform all the central venous cannulations and gain experience (a "central venous access team")

 Technique characteristics: Success rate for vein cannulation
Success rate of central placement
Complication rate.
Applicability to patients of different ages
Ease of learning
Puncture of a visible and/or palpable vein or 'blind' venepuncture based on knowledge of anatomy

Equipment available: Availability of suitable apparatus
Suitability of material for long term cannulation

Hazards of IV Drips
Most complications may be related to:
* problems of insertion - injury to vein, artery or nerve
* maintenance
* the infused fluid - incompatible blood transfusion
* incorrect placement - tissuing and extravasation
* thrombophlebitis - this is the most common and usually related to the irritant nature of some fluids and may be reduced by buffering and heparinization
Careful sitting, fixation and fluid modification reduces the rate of complication. At all sites, complications increase with the duration of the drip, and are reduced by changing drips routinely every 48 hours.

VI.3. Urethral Catheterisation
The indications for this procedure are:
* to relieve urinary retention
* to collect an uncontaminated urine specimen
* to monitor urinary output in critically ill patients
* to perform bladder tests (cystogramme)
* to act as a tamponade after prostatic surgery

The contraindications to the procedure are:
* active prostatitis
* urethral disruption - eg. in pelvic fractures
A catheter should be pre-sterilized and single-use with calibration on the French (Charriere) scale indicating external diameter in millimetres (12-18 for adults). It should not be so large as to inhibit urethral secretion drainage.

There are several types of catheter:
* Foley: a balloon at the tip to keep it in the bladder
* Jacques: the simplest, is straight with a smooth round tip
* Tiemann: less flexible curved olivary tip and side holes
* Coude (Bicoude): elbow tip useful in prostatic hypertrophy
* Red rubber: no balloon, useful when catheter is not left in dwelling.

The important points of technique are:
* full sterile conditions to reduce the risk of infection and damage to the urethral mucosa
* adequate lubrication of the urethra with an antiseptic/anaesthetic gel
* patient lies supine - females with knees flex and heels together
* inflate and deflate balloon to ensure function and coat the end with lubricant
* the hand used to hold the penis or labia does not touch the catheter
* catheter inserted with steady gentle pressure, resistance indicating the possibility of a stricture
* catheter inserted to the hilt, the balloon inflated with 5-10mls of sterile water and withdrawn so balloon rests at bladder neck
* the system should be considered closed.

VI.4. Biopsy
The procedure of biopsy plays a critical role in the diagnosis of disease as it is a method of obtaining a tissue specimen for histopathological investigation.
It is well to be aware that the diagnosis made from a biopsy specimen is only accurate for that particular piece of tissue and only on the day the biopsy was performed.
It is essential that the tissue taken at biopsy is representative of the disease process.
There are several types of biopsy and each has particular indications:

Incisional (partial) Biopsy
It is essential that the most representative area of a lesion is selected and this in most cases should include the central and deeper aspects as well as the edge and a margin of "normal" tissue. It is usually assumed that an incisional biopsy is taken for diagnostic purposes alone.

Excisional (total) Biopsy
For discrete lesions, excisional biopsy is ideal as the whole lesion is available for examination and may be subdivided as required for several diagnostic tests. If a wide margin of normal tissue is included the bniopsy may serve as the definitive treatment. If the biopsy is excisional it is assumed that the surgeon is seeking advice on the margins (ie. are they clear of the lesion).

Percutaneous Core Biopsy
A very satisfactory method of biopsy for subcutaneous tissues such as breast, thyroid, liver, kidney, muscle, bone and bone marrow. Long sharp needles with an ensheathing cannula are used with the biopsy needle being split or notched.

Cytological Biopsy - FNAC
this method is appropriate for examination of aspirates of fluids (peritoneal, bone marrow) and for fine needle aspiration of solid lesions. The technique has been extended to obtain surface smears (Papanicolaou test). The technique is very simple and may be performed with needles ranging from 19 to 25 gauge.

Accuracy and precision should be observed in every step of:
* selection of biopsy site
* writing-up the pathology request
* fixation and transmission of the specimen
* determination of the planes and number of sections
* examination and reporting.

Some general points:
* a well-planned biopsy should ideally be performed by the surgeon who will be responsible for the definitive management
* state whether the biopsy is incisonal or excisional
* peripheral incisions of a skin or mucosal bniopsy should be made at right angles to the surface
* be aware that some lesions (eg.SCC) may be "collar-stud" in cross section and allow a margin of "normal" tissue for excisional biopsy
* minimal distortion and damage to the tissue
* make an accurate sketch of the biopsy site (show lines of excision)
* where possible the specimen should be orientated by placement of sutures and unless indicated, a single sutue on a specimen is interpreted as marking "12 o'clock"
* for fixation, the specimen should be placed in at least ten times it's own volume of 10% buffered formal saline
* a provisional or differential diagnosis should be given on the request form
* the size of the biopsy specimen is important - width, length and depth
* for bone lesions always send relevant radiographs.

Biopsy specimens may be examined following:
* paraffin section
* frozen section - not reliable for definitive diagnosis but useful when major excisional surgery will follow or for re-excision specimens of incompletely excised malignancies;
and by:
* light
* electron
* immunofluorescent microscopy - the specimen is NOT placed in a fixative but should be sent in a container of normal saline and should reach the laboratory within 30 minutes.


Surgical egress involves repairing wounds of any type and reversing the pathways of access.

There are two fundamental factors to be considered in the closure of a wound:
* when to close - influenced by degree of contamination
* how to close - influenced by the tissue type and if a defect exists.
Wound closure should most optimally use the natural processes of healing to achieve the best functional and anatomical results bearing in mind that only certain tissues retain regenerative properties:
* epithelium
* bone, bone marrow, liver
* linings of vessels, joints and body cavities.

Healing of all other subepithelial tissues is by scar formation.

The surgical management of a wound therefore aims to achieve first intention healing wherever possible and this implies rapid and subtle re-epithelialization with minimal subepithelial fibrosis (ie. scar tissue).

Th phases of healing are identical for first and second intention healing with only the degree and duration of each varying:
* lag phase - 2 to 5 days
* epithelial repair
* proliferative phase - after day 3
* maturation phase - 60 to 100 days
* wound contraction - begins within a few days
* scar contracture and spread - 3 to 12 month process.
Hypertrophic scars result usually from tension (may be reduced with elastic pressure garments) whereas keloid develops with overproduction of collagen widely around the wound.


II.1. Timing

II.1.i. Immediate (Primary) Closure
This is the preferred method for clean and tidy wounds and for most, a layered anatomical closure is employed using sutures as fine as is compatible with the tensile forces acting on the wound.
If a defect cannot be closed without tension, a graft or flap repair may be employed.

II.1.ii. Delayed Closure

If there is doubt that an untidy wound can be converted to a tidy one, it is better not to close the wound in order that the risk of infection and wound breakdown be reduced.
Bony fractures may require external fixation which facilitiates repair and speeds soft tissue healing especially if an arterial or neural anastomosis has been undertaken.
If body cavities have been breached their linings should be repaired, and if the larte bowel has been perforated it is preferable to make a deliberate entero-cutaneous fistula.
Open wounds treated by delayed closure under dressings heal by granulation tissue and form a scar which is an acceptable price for low morbidity and mortality.

Delayed primary closure (DPC) - achieved between days 2 and 5 whilst the lag phase is still in progress and little fibroblastic activity has occurred. The tissues are soft and the results approach primary healing.

Secondary closure - induction of more rapid healing after the first week may be achieved either by skin graft or by apposition of granulating surfaces (reduces the volume of scar tissue) if tension allows. This latter technique is known as healing by third intention.

II.2. Techniques
All tissue layers should be neatly apposed and sutured without undue tension:
* skin - sutured with edge eversion and precise apposition
* connective tissue - inverted edges may be desirable.
Surface defects that cannot be closed with sutures may be managed by a variety of techniques:
* flaps - distant or local
* grafts - skin or composite (may involve micro' anastomosis).

Drains are mechanical conduits designed to conduct actual or potential collections of fluids or gas to the exterior.
L'Histoire Encore Une Autre Fois!
A million years ago, as now, a wound implied three major medical problems:
* mechanical disruption
* bleeding
* infection.
The clinical difference between a sterile and infected wound was noted by Hippocrates in about 400BC but the Egyptians also certainly recognised "good" and "bad" wounds. the Egyptians were the first to encourage pus bonum et laudabile and rivers of pus flowed for another 3500 years. This is, therefore, wound drainage per via naturalis.

The iatros of Hippocratic times clearly describes using a linen tent to keep open a surgical wound made in the chest to drain away pus and then at a later stage using a hollow tin drain which is gradually shortened as the pus becomes more scanty.

Daring as this operation may seem for the times it was probably suggested by the natural course of events (ie. spontaneous exit of pus) and by familiarity with holes in the chest due to stabbing with spears, daggers and arrows.

The operation was performed with the patient seated on a firm stool - the stoicism of the patient taken for granted. The drain was not resuscitated until the 19th century.
In a part of the world unknown to Hippocrates, the Chinese were using acupuncture - indeed the basic meaning of this word is "drainage".

The Greeks' barbarous habit of slitting veins to restoring bodily balance was totally unknown to the ancient Chinese - their solution was much more subtle. The Chinese conceived a set of imaginary spiritual vessels, or "meridians", containing not blood but ch'i, which when needled allowed the inward or outward flow of energy rather than bodily fluids. The origins of this practice come almost certainly from true surgical drainage.
Celsus describes suturing a wound with fibulae but not apposing the edges tightly in order to allow drainage - this is surgical drainage in it's simplest form.

III.1. Classification

Drains may be classified in various ways depending on:
* purpose - therapeutic or precautionary
* function - active or passive
* mode of action - open or closed
* material used - rubber or plastic.

III.1.i. Therapeutic and Precautionary Drainage
Therapeutic drains are used to collect established pus, blood, tissue fluid, and air.
Precautionary drains are inserted at operation to remove anticipated collections.

III.1.ii. Passive and Active Drains
Passive drains function by differential pressures between the body and exterior. Reverse movements may occur and hence there is an increased risk of infection.
Active drains utilise closed low-pressure suction forces and hence dependency is not essential. This is the most popular, effective and appropriate method of prophylactic drainage.
They collapse supple tissue minimising the risk of haemtoma and serous fluid collection.

III.1.iii. CLosed and Open Drains
Closed drains may be led to a receptacle with or without the use of suction, thus avoiding spillage and soiling of dressings, and minimising the risk of infection (particularly if a on-way valve is incorporated). They are essential when reverse flow will be hazardous.
Open drains which are led in to dressings were often used in the past but they inevitably increased the risk of infection, were messy (requiring frequent dressing changes) and made fluid volume measurement inpossible.

III.1.iv. Materials and Construction
Most modern tube drains are made of soft, pliable silicone rubber. The holes in the drain tubes must be small enough not to entrap viscera but large enough to allow uninterupted passage of unwanted fluid. They must be introduced at a distance from the wound to reduce the risk of infectionand take the most direct pathway to the surface. Multiple drains may be used at different levels but each should be sutured to the surface to prevent inadvertent removal.

III.2 Complications of Drainage
The main complications of drainage tubes are:
* infection
* injury to adjacent tissue
* difficulty of removal
and hence drains should be chosen with the risk of infection, erosion and irritation in mind.
Most drains have a radiopaque strip extending along their length to facilitate their detection if lost within a body cavity.

III.3. To Drain or not to Drain?
When deciding whether to drain a wound the surgeon should consider:
* should the wound be closed?
* will the drain prevent a haematoma and facilitate primary healing?
If the answer to both questions is YES, then a closed suction drain is required.

There is a large variety of modern wound dressings and their functions increase with improving technology.
Some wounds, particularly those clean and closed primarily or in areas of difficult access, may be left exposed without surface dressings.

The Last of History
Wounds have dressed since antiquity and with a prodigious number and variety of organic and synthetic agents.
Mesopotamia: herbs, mud, oil and dung
Egypt: fresh meat (on the first day), salt and copper pigments, willow leaves and dung (for inflamed wounds), opium and herbs, honey and grease salve with lint, myrrh and other resins.
Greece: wine, wool, and fig tree sap, sponge and leaves, greasy wool, wild celery, zinc salve, and fresh meat.
India: honey and ghee salve; sesamum, honey and ghee with lint; herbs, cow's urine and curd cream.
Rome: wool and honey; honey and lint; slices of veal; copper, lead, mercury, zinc and antimony salts.
Galen: flour and oil, dove's dung, writing ink.

IV.1. Functions of Dressings
Most wounds are dressed and the dressing serves the following purposes:
* assist in maintaining wound edge apposition
* help prevent post-operative haemorrhage and oedema
* immobilize and elevate the wound
* absorb exudate
* protection from bacterial colonisation
The dressing should:
* allow ready access and be easily removed without causing damage to the wound
* reduce the tendancy for drying but allow the passage of oxygen, carbon dioxide and water vapour - thick scabs form on dry wounds and cause them to heal slowly
* be impermeable to bacteria from within and without

IV.2. Types of Dressings
A wide variety of dressings is required to meet the above requirements and a number of dressing combinations is used in differing circumstances.

IV.2.i. Dressing Tissues
Simple dressing tissues are woven gauze swabs which act as sterile absorbents. More complex dressings may contain an inner cotton layer with a non-absorbent layer below and a liquid retardent non-absorbent surface layer. These dressings need to be held onto the wound with an adhesive tape, stretch-crepe or tube mesh.

IV.2.ii. Island Dressings
The simple band-aid is the analogy. They consist of a minimally adherent pad in the centre of a an adhesive backing, coever the wound and require no additional bandaging or crepe. The surface is usually water and impermeable.

IV.2.iii. Semi-Permeable Films
Shallow wounds may be covered with transparent, sterile, adhesive polyurethane film which is permeable to water vapour and air but not to bacteria and fluids. This dressing may be combined with a dressing tissue or an island dressing. They allow easy inspection of a wound and greater mobility and comfort - eg. the patient may shower.

* wound infection
* wound dehiscence
* incisional hernia
* wound sinus

V.1. Wound Infection
Despite the progress made with improvements in aseptic techniques and more powerful antibiotics the incidence of post-operative infection is still in the order of 10% and this is particularly so if pre-operative sepsis is present.

Certain factors should be considered in the aetiology:
* preoperative - any existing infection
* operative - lapses in theatre technique
* postoperative - cross infection in the ward
Typically the infection may commence within the first 48 hours post-operatively but may not appear for up to 3 weeks if chemotherapy has been used.
The patient will complain of pain and swelling in and around the wound together with the general symptoms of an infection and will run a swinging pyrexia.
The wound will be red, swollen, hot and tender and may be draining pus.
The treatment involves drainage of any pus and the administration of suitable antibiotics.

V.2. Wound Dehiscence
This is most commonly seen in surgery of the abdomen.
Complete wound dehiscence will lead to a burst abdomen and bowel evisceration, whilst a subcutaneous dehiscence causes incisional hernia with the muscle and fascia giving way and leaving the skin intact.
The common causes of wound dehiscence are:
* imperfect technical closure
* increased intra-abdominal pressure from distension, coughing or straining
* local tissue necrosis, major deep infection and digestion of the wound by a GI leak
* systemic causes such as renal failure, steroid administration and malignant cachexia.
Treatment of a burst abdomen will usually involve a mass closure with skin buttons to compensate for differences in the tensile properties of skin and underlying tissues.
Prevention of wound dehiscence requires correct suturing technique (mass closure has a lower incidence), and non-absorbable sutures in the deeper layers.

V.3. Incisional Hernia
The causes of incisional hernia are similar to wound dehiscence but wound infection is by far the most common, and most will therefore occur and be recognised before patient dischage.
The principles of repair are:
* wide exposure of the margins of the defect to healthy tissue
* systematic closure with non-absorbable sutures using a figure-of-eight, near-far, far-near
* excision of redundant subcutaneous tissue and skin
* suction drainage.

V.4. Wound Sinus
A persistent sinus is usually caused by persistent infection around a deep suture which must be removed, although a necrotic portion of tissue (eg. sequestrum) and persistent deep disease are further causes.

 Two Hand Technique
The two-hand square knot is the easiest and most reliable for tying most suture materials. It may be used to tie surgical gut, virgin silk, surgical cotton, and surgical stainless steel.
Standard technique of flat and square ties with the additional throws if indicated by the surgical circumstances and the experience of the operator should be used to tie MONOCRYL(poliglecaprone 25) suture, Coated VICRYL(polyglactin 910), Coated VICRYLRAPIDE(polyglactin 910) suture, PDS II(polydioxanone) suture, ETHICON nylon suture, ETHIBOND EXCEL polyester suture, PERMA-HAND silk suture, and PROLENE polypropylene suture.

White strand placed over extended index finger of left hand acting as bridge, and held in palm of left hand. Purple strand held in right hand.

Purple strand held in right hand brought between left thumb and index finger.

Left hand turned inward by pronation, and thumb swung under white strand to form the first loop.

Purple strand crossed over white and held between thumb and index finger of left hand.

Right hand releases purple strand. Then left hand supinated, with thumb and index finger still grasping purple strand, to bring purple strand through the white loop. Regrasp purple strand with right hand.

Purple strand released by left hand and grasped by right. Horizontal tension is applied with left hand toward and right hand away from operator. This completes first half hitch.

Left index finger released from white strand and left hand again supinated to loop white strand over left thumb. Purple strand held in right hand is angled slightly to the left.

Purple strand brought toward the operator with the right hand and placed between left thumb and index finger. Purple strand crosses over whit strand.

By further supinating left hand, white strand slides onto left index finger to form a loop as purple strand is grasped between left index finger and thumb.

Left hand rotated inward by pronation with thumb carrying purple strand through loop of white strand. Purple strand is grasped between right thumb and index finger.

Horizontal tension applied with left hand away from and right hand toward the operator. This completes the second half hitch.

The final tension on the final throw should be as nearly horizontal as possible.
 One-Hand Technique
Wherever possible, the square knot is tied using the two-hand technique. On some occasion it will be necessary to use one hand, either the left or right, to tie a square knot. These illustrations employ the left-handed technique.
The sequence of throws illustrated is most commonly used for tying single suture strands. The sequence may be reversed should the surgeon be holding a reel of suture material in the right hand and placing a series of ligatures. In either case, it cannot be too strongly emphasized that the directions the hands travel must be reversed proceeding from one throw to the next to ensure that the knot formed lands flat and square. Half hitches result if this precaution is not taken.

White strand held between thumb and index finger of left hand with loop over extended index finger. Purple strand held between thumb and index finger of right hand.

Purple strand brought over white strand on left index finger by moving right hand away from operator.

With purple strand supported in right hand, the distal phalanx of left index finger passes under the white strand to place it over tip of left index finger. Then the white strand is pulled through loop in preparation for applying tension.

The first half hitch is completed by advancing tension in the horizontal plane with ht left hand drawn toward and right hand away from the operator.

White strand looped around three fingers of left hand with distal end held between thumb and index finger.

Purple strand held in right hand brought toward the operator to cross over the white strand. Continue hand motion by flexing distal phalanx of left middle finger to bring it beneath white strand.

As the middle finger is extended and the left hand pronated, the white strand is brought beneath the purple strand.

Horizontal tension applied with the left hand away and right hand toward the operator. This completes the second half hitch of the square knot. Final tension should be as nearly horizontal as possible.

Suture Materials
The requirement for wound support varies in different tissues from a few days for muscle, subcutaneous tissue, and skin; weeks or months for fascia and tendon; to long-term stability, as for a vascular prosthesis.  The surgeon must be aware of these differences in the healing rates of various tissues and organs.  In addition, factors present in the individual patient, such as infection, debility, respiratory problems, obesity, etc., can influence the postoperative course and the rate of healing.
Suture selection should be based on the knowledge of the physical and biologic characteristics of the material in relationship to the healing process.  The surgeon wants to ensure that a suture will retain its strength until the tissue regains enough strength to keep the wound edges together on its own.  In some tissue that might never regain preoperative strength, the surgeon will want suture material that retains strength for a long time.  If a suture is going to be placed in tissue that heals rapidly, the surgeon may prefer to select a suture that will lose its tensile strength at about the same rate as the tissue gains strength and that will be absorbed by the tissue so that no foreign material remains in the wound once the tissue has healed.  With all sutures respect to drainage and closure of infected wounds.  The amount of tissue reaction caused by the suture encourages or retards the healing process.

When all these factors are taken into account, the surgeon has several choices of suture materials available.  Selection can be made on the basis of familiarity with the material, its ease of handling, and other subjective preferences.

Sutures can conveniently be divided into two broad groups: absorbable and nonabsorbable.  Regardless of its composition, suture material is a foreign body to the human tissues in which it is implanted and to a greater or lesser degree will elicit a foreign body reaction.

Two major mechanisms of absorption result in the degradation of absorbable sutures.   Sutures of biological origin such as surgical gut are gradually digested by tissue enzymes.  Sutures manufactured from synthetic polymers are principally broken down by hydrolysis in tissue fluids.

Nonabsorbable sutures made form a variety of nonbiodegradable materials are ultimately encapsulated or walled off by the body's fibroblasts.  Nonabsorbable sutures ordinarily remain where they are buried within the tissues. When used for skin closure, they must be removed postoperatively.

A further subdivision of suture materials is useful: monofilament and multifilament.  A monofilament suture is made of single strand.  It resists harboring microorganisms, and it ties down smoothly.  A multifilament suture consists of several filaments twisted or braided together.  This gives good handling and tying qualities.  However, variability in knot strength among multifilament sutures might arise from the technical aspects of the braiding or twisting process.

The sizes and tensile strengths for all suture materials are standardized by U.S.P. regulations.  Size denotes the diameter of the material.  Stated numerically, the more zeros (0's) in the number, the smaller the size of the strand.  As the number of  0's decreases, the size of the strand increases.  The 0's are designated as 5-0, for example, meaning 00000 which is smaller than a size 4-0.  The smaller the size, the less tensile strength the strand will have.  Tensile strength of a suture is the measures pounds of tension that the strand will withstand before it breaks when knotted.
Principles of Suture Selection
The surgeon has a choice of suture materials from which to select for use in body tissues.  Adequate strength of the suture material will prevent suture breakage.  Secure knots will prevent knot slippage.  But the surgeon must understand the nature of the suture material, the biological forces in the healing wound, and the interaction of the suture and the tissues.  The following principles should guide the surgeon in suture selection.
When a wound has reached maximal strength, sutures are no longer needed.  Therefore:
Tissues that ordinarily heal slowly such as skin, fascia, and tendons should usually be closed with nonabsorbable sutures.
Tissues that heal rapidly such as stomach, colon, and bladder may be closed with absorbable sutures.
Foreign bodies in potentially contaminated tissues may convert contamination to infection.  Therefore:
Avoid multifilament sutures which may convert a contaminated wound into an infected one.
Use monofilament or absorbable sutures in potentially contaminated tissues.
Where cosmetic results are important, close and prolonged apposition of wounds and avoidance of irritants will produce the best results.  Therefore:
Use the smallest inert monofilament suture materials such as nylon or polypropylene.
Avoid skin sutures and close subcuticularly, whenever possible.
Under certain circumstances, to secure close apposition of skin edges, skin closure tape may be used.
Foreign bodies in the presence of fluids containing high concentrations of crystalloids may act as a nidus for precipitation and stone formation.  Therefore:
In the urinary and billary tract, use rapidly absorbed sutures.
Regarding suture size:
Use the finest size, commensurate with the natural strength of the tissue.
If the postoperative course of the patient may produce sudden strains on the suture line, reinforce it with retention sutures.  Remove them as soon as the patient's condition is stabilized.
Absorbable Sutures
The United States Pharmacopoeia (U.S.P.) defines an absorbable surgical suture as a "sterile strand prepared from collagen derived from healthy mammals or a synthetic polymer.  It is capable of being absorbed by living mammalian tissue, but may be treated to modify its resistance to absorption.   It may be impregnated or coated with a suitable antimicrobial agent.  It may be colored by a color additive approved by the Federal Food and Drug Administration (F.D.A.)."
Nonabsorbable Sutures
By U.S.P. definition, "nonabsorbable sutures are strands of material that are suitably resistant to the action of living mammalian tissue.  A suture may be composed of a single or multiple filaments of metal or organic fibers rendered into a strand by spinning, twisting, or braiding.  Each strand is substantially uniform in diameter throughout its length within U.S.P. limitations for each size.  The material may be uncolored, naturally colored, or dyed with an F.D.A. approved dyestuff.  It may be coated or uncoated; treated or untreated for capillarity."
 Principles of Suture Selection
The surgeon has a choice of suture materials from which to select for use in body tissues. Adequate strength of the suture material will prevent suture breakage. Secure knots will prevent knot slippage. But the surgeon must understand the nature of the suture material, the biological forces in the healing wound, and the interaction of the suture and the tissues. The following principles should guide the surgeon in suture selection.
When a wound has reached maximal strength, sutures are no longer needed. Therefore:
Tissues that ordinarily heal slowly such as skin, fascia, and tendons should usually be closed with nonabsorbable sutures.
Tissues that heal rapidly such as stomach, colon, and bladder may be closed with absorbable sutures.
Foreign bodies in potentially contaminated tissues may convert contamination to infection. Therefore:
Avoid multifilament sutures which may convert a contaminated wound into an infected one.
Use monofilament or absorbable sutures in potentially contaminated tissues.
Where cosmetic results are important, close and prolonged apposition of wounds and avoidance of irritants will produce the best results. Therefore:
Use the smallest inert monofilament suture materials such as nylon or polypropylene.
Avoid skin sutures and close subcuticularly, whenever possible.
Under certain circumstances, to secure close apposition of skin edges, skin closure tape may be used.
Foreign bodies in the presence of fluids containing high concentrations of crystalloids may act as a nidus for precipitation and stone formation. Therefore:
In the urinary and billary tract, use rapidly absorbed sutures.
Regarding suture size:
Use the finest size, commensurate with the natural strength of the tissue.
If the postoperative course of the patient may produce sudden strains on the suture line, reinforce it with retention sutures. Remove them as soon as the patient's condition is stabilized.
 Absorbable Sutures
The United States Pharmacopoeia (U.S.P.) defines an absorbable surgical suture as a "sterile strand prepared from collagen derived from healthy mammals or a synthetic polymer. It is capable of being absorbed by living mammalian tissue, but may be treated to modify its resistance to absorption. It may be impregnated or coated with a suitable antimicrobial agent. It may be colored by a color additive approved by the Federal Food and Drug Administration (F.D.A.)."
 Nonabsorbable Sutures
By U.S.P. definition, "nonabsorbable sutures are strands of material that are suitably resistant to the action of living mammalian tissue. A suture may be composed of a single or multiple filaments of metal or organic fibers rendered into a strand by spinning, twisting, or braiding. Each strand is substantially uniform in diameter throughout its length within U.S.P. limitations for each size. The material may be uncolored, naturally colored, or dyed with an F.D.A. approved dyestuff. It may be coated or uncoated; treated or untreated for capillarity."

Surgical Needles
Necessary for the placement of sutures in tissue, surgical needles must be designed to carry suture material through tissue with minimal trauma.  They must be sharp enough to penetrate tissue with minimal resistance.  They should be rigid enough to resist bending, yet flexible enough to bend before breaking.  They must be streile and corrosion-resistant to prevent introduction of microorganisms of foreign bodies into the wound.
To meet these requirements, the best surgical needles are made of high quality stainless steel, a noncorrosive material.  Surgical needles made of carbon steel may corrode, leaving pits that can harbor microorganisms.  All ETHICON stainless steel needles are heat-treated to give them the maximum possible strength and ductility to perform satisfactorily in the body tissues for which they are designed.  ETHALLOY needle alloy, a noncorrosive material, was developed for unsurpassed strength and ductility in precision needles used in cardiovascular, ophthalmic, plastic, and microsurgical procedures.

Ductility is the ability of the needle to bend to a give angle under a given amount of pressure, called load, without breaking.  If too great a force is applied to a needle it may break, but a ductile needle will bend before breaking.  If a surgeon feels a needle bending, this is a signal that excessive force is being applied.  The strength of a needle is determined in the laboratory by bending the needle 900, that required force is a measurement of the strength of the needle.  If a needle is weak, it will bend too easily and can compromise the surgeon's control and damage surrounding tissue during procedure.

Regardless of ultimate intended use, all surgical needles have three basic components: the attachment end, the body, and the point.

The majority of sutures used today have appropriate needles attached by the manufacturer.  Swaged sutures join the needle and suture together as a continuous unit that is convenient to use and minimize tissue trauma.  ATRALOC surgical needles, which are permanently swaged to the suture strand, are supplied in a variety of sizes, shapes, and strengths.  Some incorporate the CONTROL RELEASE needle suture principle which facilitate fast separation of the needle from the suture when desires by the surgeon.  Even though the suture is securely fastened to the needle, a slight, a straight tug on the needleholder will release it.  This feature allows rapid placement of many sutures, as in interrupted suture techniques.

The body, or shaft, of a needle is the portion which is grasped by the needleholder during the surgical procedure.  The body should be as close as possible to the diameter of the suture material.  The curvature of the body may be straight, half-curved, curved, or compound curved.  The cross-sectional configuration of the body may be round, oval, side-flattened rectangular, triangular, or trapezoid.  The oval, side-flattened rectangular, and triangular shapes may be fabricated with longitudinal ribs on the inside or outside surfaces.  This feature provides greater stability of the needle in the needleholder.

The point extends from the extreme tip of the needle to the maximum cross-section of the body.  The basic needle points are cutting, tapered, or blunt.  Each needle point is designed and produced to the required degree of sharpness to smoothly penetrate the types of tissue to be sutured.

Surgical needles vary in size and wire gauge.  The diameter is the gauge or thickness of the needle wire.  This varies from 30 microns (.001 inch) to 56 mil (.045 inch, 1.4 mm).  Very small needles of fine gauge wire are needed for microsurgery.  Large, heavy gauge needles are used to penetrate the sternum and to place retention sutures in the abdominal wall.  A broad spectrum of sizes are available between these two extremes.

Of the many types available, the specific needle selected for use is determined by the type of tissue to be sutured, the location and accessibility, size of the suture material, and the surgeon's preference.

Sutures are used to hold wounded tissue and skin together. Plain sutures penetrate the skin and underlying tissue over and under the wound and are individually tied off (A). Continuous plain sutures progress continuously down the wound, having the loop under the skin and tissue set obliquely (B). Mattress sutures, also of the interrupted (C) and continuous (D) type, take some of the skin along both sides of the wound before continuing across the wound site. Retention sutures (E) are strengthened by a plastic or rubberized sleeve on their outer surface and are held together by especially strong ties. The removal of sutures is carried out under sterile conditions. The wound site is cleaned and every other suture is first removed (F). If the site is healed the remaining sutures are removed. A final dressing is then applied to the wound site. A

1. Marshall, V., Ludbrook, J. Clinical Sciences for Surgeons. Basic Surgical Practice.
Sydney: Butterworths, 1988.
2. Seward, G.R., Harris, M., McGowan, D.A. Killey and Kay's Outline of Oral Surgery. Part One.
Bristol: Wright, 1987.
3. Majno, G. The Healing Hand. Man and Wound in the Ancient World.
London: Harvard University Press, 1991.
4. Haeger K. The Illustrated History of Surgery.
London: Harold Starke, 1989.
5. Gomella L.G. Clinician's Pocket Reference.
6th edn., New Jersey: Prentice-Hall International Inc., 1989.
6. Jolly M., Painter D. Biopsy Specimens.
Unpublished and Personal Communication.

Bladder Catheterization

In order to catheterize the male urethra, sterile gloves are donned and the patient is draped with the drape window opening around the penis. The area of the meatus is cleaned with a cotton swab soaked with antiseptic solution (A). The catheter is lubricated to about 20 cm of its length and advanced this distance or until urine flows (B). Having the patient bear down as if voiding facilitates insertion of the catheter. The catheter is secured to the thigh or abdomen and connected to a collecting receptacle (C). A 1 Pubic symphysis bone
2 Urinary bladder
3 Uterus
4 Rectum
5 Catheter