Factors involved in abdominal wall closure and subsequent incisional hernia.

Incisional hernia is a frequent complication of abdominal wall closure with a reported incidence of between 5% and 15% following vertical midline incisions at one-year follow-up. Evidence from randomised clinical trials and meta-analysis indicate that a continuous running non-absorbable or slowly absorbed suture such as polydioxanone is the method of choice for abdominal wall closure. Continuous polydioxanone has a similar incisional hernia rate to its non-absorbable counterparts but causes less chronic pain and wound sinuses. Evidence from randomised clinical trials indicates that a lateral paramedian incision is associated with a lower incidence of incisional hernia when compared with other abdominal incisions. Transverse abdominal incisions have no advantage over midline incisions in reducing incisional hernia rate. Although experimental and clinical evidence indicate that a greater number of stitches with a suture length to wound ratio of at least 4:1 is associated with a lower incidence of incisional hernia, there is no evidence from randomised clinical trials to support this. Intuitively one may think that putting as little tension as possible on the closure is important, but there is no evidence for this. Clinical trials evaluating these factors would be difficult to undertake making it important that surgeons continue to audit incisional hernia rates following abdominal closure.