Abdominal wall closure

Abstract

For decades, opening and closing the abdominal wall has been a rite of passage for surgical training. This task was often left to a more junior member of the surgical team, as reward for assisting with a long laparotomy. Supervision of this task was variable. Yet, closure of the abdominal wall is an important step for the patient; the risk is of incisional hernia, the commonest major complication of a laparotomy, with its attendant symptoms and frequent need for further surgery. Despite this, there is a noticeable lack of research focusing on the optimal method to close the abdominal wall. Indeed, when the first European Hernia Society (EHS) guidelines1 on the closure of the abdominal wall were published in 2015, one of the few strong recommendations to reduce the risk of incisional hernia formation was to avoid the midline. Yet the midline remains the main technique of access to the abdomen at open surgery, and often for specimen extraction after laparoscopic surgery. Studies have been done on suture type, absorbable versus nonabsorbable, rapidly versus slowly absorbable, mass versus layered closure, continuous versus interrupted, and so on. However, many of the prospective trials compared several variables between the study arms, and failed to monitor the technical details of the suturing technique. Indeed, in the 23 RCTs included in the MATCH review2, there was no evidence when using the same suture or suture technique in both study arms that any suture material was superior to another, or that continuous suture was superior to interrupted suture. It is well recognized that closure of the abdominal wall can fail, both acutely, as in the so-called burst abdomen, and more chronically, as an incisional hernia. In the acute burst abdomen, technical factors such as failure of the suture knot are well recognized, in addition to the possible effects of abdominal hypertension. When an incisional hernia develops, surgeons are more likely to blame the patient, such as poor collagen, obesity, smoking, steroid use and/or cachexia, and perhaps not reflect on their closure technique. At the time of publication, the EHS guidelines noted the improved results, in terms of reducing burst abdomen, wound infection rate and lower incisional hernia rate of the small bite, small-stitch closure technique, first reported by Israelsson’s group3. Still based on the old concept of the 4 : 1 suture to wound length ratio4, the use of a smaller suture size with small bites of the linea alba was revolutionary, but has not gained rapid acceptance in surgical practice. A second randomized trial from the Netherlands5 has confirmed some of these findings in terms of fewer incisional hernias, but no significant reduction in wound infection rate or the risk of burst abdomen. But, as in many RCTs, the exclusion criteria make generalization of the study’s findings difficult. Both trials excluded emergency surgery, as well as obese patients – the group that perhaps has the highest risk of incisional hernia. A Danish group6 used the small-stitch, small-bite technique in a large series of emergency midline laparotomies, with a marked reduction in the rate of burst abdomen compared with historical controls. The use of so-called near and far (Hughes) stitches has also been described, but it too has not become common practice. However, the Hughes Abdominal Repair Trial (HART)7 is busy recruiting from centres throughout the UK, and its results are awaited. Both arms of this trial7 use continuous large-bite, large-stitch mass closure of the midline, with the study arm also incorporating a series of horizontal and two vertical mattress sutures within a single non-absorbable suture to the linea alba. The superiority of mesh in incisional hernia repair over suture repair in terms of hernia recurrence is well known. This has led to an active interest in using mesh at the same time as abdominal wall closure, especially in high-risk groups such as those undergoing aortic aneurysm surgery and obese patients, with promising results8. To date, however, mesh-augmented closure has been compared with large-stitch, largebite closure, so it remains to be seen what additional benefit mesh may have in abdominal wall closure over small-stitch, small-bite techniques. In addition, what mesh and where should it be sited are unanswered questions. Effective healing of the abdominal wall without incisional hernia formation is not just about suture type or suture technique. Particularly when it comes to elective surgery, improving exercise tolerance, treating sarcopenia, weight loss in the