BURST ABDOMEN DAVID SIRAIT, M.D

OVERVIEW  Definition  Incidence  Clinical Manifestations  Risk Factors For Abdominal Wound Dehiscence  Pre-Operative Factors Operative Factors  Post-Operative Factors  Treatment  Non-operative Treatment  Operative Treatment  Retention Sutures  The Uncloseable Abdomen

DEFINITION  Also known as abdominal wound dehiscence, wound failure, wound disruption, evisceration, and eventration.  Describes partial or complete postoperative separation of an abdominal wound closure with protrusion or evisceration of the abdominal contents.  Wound dehiscence and incisional hernia are part of the same wound failure process; it is timing and healing of the overlying skin that distinguishes the two.  Dehiscence of the wound occurs before cutaneous healing, while incisional hernias lie under a well-healed skin incision.

INCIDENCE  Wound dehiscence continues to be a major complication of abdominal surgery despite significant progress in operative and perioperative care over the last few decades.  Accompanied by high morbidity and mortality.  Reported incidence varies between 0.2% to 6%.  Associated with mortality rates between 10% and 40%

CLINICAL MANIFESTATIONS  Dehiscence usually declares itself 7-14 days post-op. and may occur without warning.  May manifest following straining or removal of the sutures.  Patient often notes a “ripping sensation” or a feeling that “something has given way”.  Impending dehiscence of the abdominal wall is often preceded by the appearance of a salmon-pink serous discharge from the wound. This is seen in up to 85% of cases.

CLINICAL MANIFESTATIONS

PRE-OPERATIVE FACTORS  Male Sex: Male : Female = 2:1  Age:  < 45 years old; dehiscence  occurs in 1.3%  > 45 years old; dehiscence  occurs in 5.4%  Emergency Operation: May be related to haemodynamic instability.  Obesity: However several studies  No association.  Uncontrolled Diabetes: well controlled diabetes is not a risk factor.  Renal failure  Jaundice  Anaemia : In some studies

PRE-OPERATIVE FACTORS  Malnutritution:  Protein deficencies: Hypo-albuminaemia can be used as a marker of malnutritution.  Vitamin C: is critical for strength gain in healing wounds. Sub-clinical vitamin c deficency is associated with an eightfold increase in the incidence of wound dehiscence. Vitamin C supplementation seems reasonable in malnourished surgical patients.  Zinc deficency.  Corticosteriods: topically or systemically, have a deleterious effect on wound healing.

OPERATIVE FACTORS  Incision type?  Closure:  Mass versus Layered Closure?  Interrupted versus Continuous Sutures?  Peritoneal Closure or not?  Suture Materials: Absorbable versus non-absorbable?  Stitch interval and Size of Tissue Bite?  Suture Length-to-Wound Length Ratio?

Incision type?  Inspite the midline incision is the most versatile The rate of dehiscence is higher in midline incisions than in transverse incisions.  Midline incision is ”non-anatomic”. It cuts across the aponeurotic fibres, as opposed to the transverse incision which cuts paralell to the fibres.  Contraction of the abdominal wall causes laterally directed tension on the closure  suture material cut through by separation of the tranversily orientated fibres.

CLOSURE? Mass versus Layered Closure?  Closure of the abdominal wall in layers has been the traditional approach.  Data have been published that suggest that mass closure (all layers of the abdominal wall taken together) is equivalent to or better than layered closure in preventing dehiscence.  Mass closure is currently favored because of its safety, efficacy, and speed.

CLOSURE? Interrupted versus Continuous Sutures?  Several randomised trials revealed no statistically significant difference in the incidence of wound disruption between the two techniques.  Several technical variations of the interupted stitch, including the interrupted ‘figure of eight’, ‘far-and-near’ technique, or interrupted “Smead-Jones’ technique did not improve outcomes.  Continuous suture is a reasonable closure technique because of its safety, efficacy, and speed.

PERITONEAL CLOSURE OR NOT?  Suturing the peritoneum is not vital to prevent wound dehiscence.  Randomised trials have shown no difference in the wound disruption rate when one-layer closure (peritoneum not sutured) and two-layer closure are compared in paramedian and midline incisions.  The peritoneal defects heal by simultaneous regeneration of the layer over the entire defect, not an incremental advancement from the wound edge, as is seen with skin.

SUTURE MATERIALS? Absorbable vs. non-absorbable sutures?  Numerous prospective and retrospective studies have shown no difference in the overall incidence of wound complications between the various absorbable and non-absorbable sutures. However some showed prolonged wound pain and suture sinuses with non-absorbable sutures.  So the choice seems to be one of personal preference.  It may be wise, however, to use a non-absorbable monofilament in the patient who has an excessive number of risk factors for delayed healing.

THE STITCH INTERVAL AND THE TISSUE BITE SIZE?  Should be 1 cm. average with a range between 1-2 cm.  Suture Length-to-Wound Length Ratio?  Should be 4:1 or greater for continuous mass closure.  A ratio < 4:1 is associated with an increased risk of abdominal dehiscence and the later development of incisional hernia.

POST-OPERATIVE FACTORS  Elevation of Intra-Abdominal Pressure (instigator of dehiscence) due to either:  Coughing  Vomiting  Ileus  Urinary retention  Wound Infection.  Radiation Therapy (Both in the past and perioperatively).  Antineoplastic Agents (postpone 2-3 weeks P.O.)

TREATMENT Non-Operative Treatment:  If patient very unstable, and there has been no evisceration.  Performed at bedside.  Involves either gauze packing of the wound or covering it with a sterile occlusive dressing.  Abdominal binder may be used to support disrupted abdominal wound.  Wound may subsequently contract to closure, or if the patient’s condition improves, delayed operative closure may be performed.  Hernia is a common sequela.

TREATMENT Operative Treatment:  For most patients immediate re-suture (usually with a mass closure) with the placement of deep retention sutures.  Pre-operative broad spectrum antibiotics should be given.  Deep bites of tissue, using plenty of suture material, and avoid excessive tension on the wound.  Close the skin fairly loosely and consider using a superficial wound drain. In the presence of gross wound sepsis, leave the skin open and pack

TREATMENT Retention sutures:  Use heavy non-absorbable suture e.g. No. 1 monofilament Nylon.  Wide interupted bites of at least 3 cm from the wound edge.  Stitch interval of 3 cm or less.  Either external (incorporating all layers peritoneum through to skin) or internal (all layers except skin) may be used.  Internal retention sutures avoid producing an unsightly ladder-pattern scar, however they are unable to be removed subsequently (increased infection risk).  Thread each suture through a short length (5-6cm) of plastic or rubber tubing to prevent suture erosion into the skin  Do not tie too tightly.  External retention sutures are usually left in for at least 3 weeks.

TREATMENT The Uncloseable Abdomen:  In a small number of patients it is inappropriate, technically unsafe or even impossible to close the abdominal wall primarily.  Conditions which may predispose to an uncloseable abdomen include:  1. major abdominal trauma.  2. gross abdominal sepsis.  3. retroperitoneal haematoma e.g. post ruptured AAA.  4. loss of abdominal wall tissue e.g. Necrotizing fasciitis. .Attempted closure  abdominal compartment syndrome.

TREATMENT  Mesh closure of the abdominal incision is usually indicated.  The defect is bridged with one or two layers of a prosthetic mesh.  The mesh is sutured in place with sutures that penetrate the full thickness of the abdominal wall.  Dressing changes and subsequent granulation tissue formation ultimately result in a surface that can be covered with a split-skin graft.

TREATMENT PTFE (e.g. Goretex)Polypropylene mesh (e.g. Prolene, Marlex) Absorbable mesh (polyglycolic acid e.g. Dexon) Soft and pliableErosion into bowel and fistula formation Temporary closure Less adhesions to bowelDense adhesions formationSubsequent incisional hernia inevitable Tolerates infection poorlyQuite tolerant to infectionGood for infected abdomen

REFERENCES  Carlson MA. Acute Wound Failure. Surgical Clinics of North America 1997; 77:  Brolin RE. Prospective, Randomised Evaluation of Midline Fascial Closure in Gastric Bariatric Operations. The American Journal of Surgery 1996; 172;  Ellis H, Colridge-Smith PD, Joyce AD. Abdominal incisions – vertical or transverse? Postgrad Med J 1984; 60: ).  Weiland DE, Bay RC, Del Sordi S. Choosing the Best Abdominal Closure by Meta- analysis. American journal of surgery 1998; 176:  Fagniez PL, Hay JM, Lacaine F, et al. Archives of Surgery 1985; 120:  Van’t Riet M, Steyerberg EW, Nellensteyn J, Bonjer HJ, Jeekel J. Meta-analysis of techniques for closure of midline abdominal incisions British Journal of Surgery; 89:  Israelsson LA, Jonsson T, Knutsson A. Suture Technique and Wound Healing in Midline Laparotomy Incisions. European Journal of Surgery 1996; 162:  Nagy KK, Fildes JJ, Mahr C, et al. Experience with Three Prosthetic Materials in Temporary Abdominal Wall Closure. American Surgeon 1996; 62:

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