Abdominal incision closure: small but important bites.

www.thelancet.com Published online July 16, 2015 http://dx.doi.org/10.1016/S0140-6736(15)60687-0 1 In The Lancet, Eva Deerenberg and colleagues’ prospective, multicentre, double-blind, randomised controlled STITCH trial shows that the rate of incisional hernia is lower with small tissue bites than with large bites. This fi nding contradicts what surgeons have thought and been taught for many decades. In the study, 560 patients undergoing abdominal surgery via midline incision at surgical and gynaecological departments in ten hospitals were randomly assigned to receive continuous wound closure with either large tissue bites (1 cm from the wound edge) or small tissue bites (5 mm from the wound edge). Patients in the small bites group had a higher ratio of suture length to wound length than those in the large bites group (5·0 [SD 1·5] vs 4·3 [1·4]) and a longer wound closure time (14 [6] vs 10 [4] min), because more stitches were placed in the wound (45 [12] vs 25 [10] stitches). At 1 year follow-up, the trial’s primary endpoint of occurrence of incisional hernia was signifi cantly less frequent in patients in the small bites group (35 [13%] of 268 patients) than in those in the large bites group (57 [21%] of 277 patients; covariate adjusted odds ratio 0·52, 95% CI 0·31–0·87). Postoperative pain or complications were similar between the groups. The investigators conclude that the previous clinical recommendation should be changed and that the small bites closure technique become the standard. The process that has led to Deerenberg and colleagues’ trial is interesting. Why has there been a previous recommendation on bite size, why should it now be changed, and what will be the consequences of this change? The suture technique has proved very important in attempts to reduce the rate of wound complications in midline incisions. Closure with a suture length to wound length ratio higher than four is important: thus, if the suture used to close the wound is less than four times longer than the wound, the rate of incisional hernia is increased by four times. Closure with a high ratio is an easy and cost-eff ective way of reducing the herniation rate. An adequate suture to wound length ratio can be accomplished with either large or small bites. For the past 40 years, the recommendation in the literature and surgical textbooks has unanimously been that closure should be with large bites. Notably, but probably not widely known, is that this recommendation was based entirely on experimental studies. Recommendations were to place stitches at least 10 mm from the wound edge because, in experimental studies, closure of the wound was weaker with smaller bites. Disagreements between these experimental fi ndings and a few clinical reports showing a lower rate of wound complications with small bites attracted little attention. The disturbing discrepancy between the clinical recommendation, based on experimental studies, and the contradictory clinical reports encouraged further studies. Newer experimental studies comparing wound strength with small and large bites subsequently took the suture length to wound length ratio into account. Studies then showed that, in wounds closed with a similar ratio, the strongest wound was actually accomplished with small bites. Investigators postulated that the rates of both wound infection and incisional hernia would be lower with small bites than with large bites. Findings from a randomised trial showed a reduced rate of wound infection and incisional hernia with small bites. Additionally, the small bites technique was cost eff ective. Thus, experimental and clinical evidence suggests that the surgical standard of closing midline incisions with large bites should be changed. However, the clinical evidence in favour of small bites has until now been one single-site randomised trial. The new STITCH trial is a very thorough and well conducted Abdominal incision closure: small but important bites