Systematic review with meta-analysis of transverse vs. vertical midline extraction incisional hernia risk following laparoscopic colorectal resections.

Background: The aim of this article is to explore the risk of incisional hernia (IH) occurrence at the site of specimen extraction following laparoscopic colorectal resection (LCR), highlighting the comparison between transverse incision versus midline vertical abdominal incision.

Methods: Analysis was conducted according to PRISMA guidelines. Systematic search of medical databases, EMBASE, MEDLINE, PubMed and Cochrane Library were performed to find all types of comparative studies reporting the incidence of IH at the specimen extraction site of transverse or vertical midline incision following LCR. The analysis of the pooled data was done using the RevMan statistical software.

Results: Twenty-five comparative studies (including 2 randomised controlled trials) on 10,362 patients fulfilled the inclusion criteria. There were 4,944 patients in the transverse incision group and 5,418 patients in the vertical midline incision group. In the random effects model analysis, the use of transverse incision for specimen extraction following LCR reduced the risk of IH development (odds ratio =0.30, 95% CI: 0.19-0.49, Z=4.88, P=0.00001). However, there was significant heterogeneity (Tau²=0.97; Chi²=109.98, df=24, P=0.00004; I²=78%) among included studies. The limitation of the study is due to lack of RCTs, this study includes both prospective and retrospective studies along with 2 RCTs which makes the meta-analysis potentially biased in source of evidence.

Conclusions: Transverse incision used for specimen extraction following LCR seems to reduce the risk of postoperative IH incidence compared to vertical midline abdominal incisions.