Abdominal Closure and the Risk of Incisional Hernia in Aneurysm Surgery - A Systematic Review and Meta-analysis

Objectives: Patients with abdominal aortic aneurysms (AAAs) have a high prevalence of incisional hernia following open repair. The choice of incision and closure technique has a significant impact on this postoperative complication. Multiple techniques exist, as well as various comparative analyses, but clinical consensus is lacking. The objective was to perform a systematic review and meta-analysis of AAA laparotomy and closure technique and the risk of incisional hernia development. Methods: The systematic review was performed according to the PRISMA guidelines. A literature search of all original research published until January 2019 was made. Outcome measures were surgical approach, closure technique, hernia rates, length of follow up, and method of hernia recognition. Groups were divided according to method of abdominal incision and closure technique. Differences in outcome between closure techniques were expressed as risk ratios with 95% confidence interval (CI) using a random effects model. Results: Fifteen studies were included with a cumulative cohort of between 388 and 3 399 patients compared in each group. Abdominal closure with a suture to wound length ratio of more than 4:1 compared with less than 4:1, RR 0.42 (95% CI 0.27-0.65), and abdominal closure with mesh compared with without mesh augmentation, RR 0.24 (95% CI 0.10-0.60) reduced the risk of incisional hernia. There were no significant differences in incisional hernia rate between transverse abdominal incision vs. vertical midline incision, RR 0.57 (95% CI 0.31-1.06) and between midline transperitoneal vs. all retroperitoneal incisions, RR 1.19 (95% CI 0.54-2.61). Conclusion: Choice of abdominal closure technique after aneurysm surgery impacts the risk of developing incisional hernia. The use of a supportive mesh significantly reduces the risk of incisional hernia in vertical midline incisions. The same is true if a suture to wound ratio of more than 4:1 is used.