Midline incision vs. transverse incision for specimen extraction is not a significant risk factor for developing incisional hernia after minimally invasive colorectal surgery: multivariable analysis of a large cohort from a single tertiary center in Korea

Abstract

Background: Incisional hernia (IH) is a commonly encountered problem even in the era of minimally invasive surgery (MIS). Numerous studies on IH are available in English literature, but there are lack of data from the Eastern part of the world. This study aimed to evaluate the risk factors as well as incidence of IH by analyzing a large cohort collected from a single tertiary center in Korea.

Methods: Among a total number of 4276 colorectal cancer patients who underwent a surgical resection from 2006 to 2019 in Korea University Anam Hospital, 2704 patients (2200 laparoscopic and 504 robotic) who met the inclusion criteria were analyzed. IH was confirmed by each patient's diagnosis code registered in the hospital databank based on physical examination and/or computed tomography findings. Clinical data including specimen extraction incision (transverse or vertical midline) were compared between IH group and no IH group. Risk factors of developing IH were assessed by utilizing univariable and multivariable analyses.

Results: During the median follow-up of 41 months, 73 patients (2.7%) developed IH. Midline incision group (n = 1472) had a higher incidence of IH than that of transverse incision group (n = 1232) (3.5% vs. 1.7%, p = 0.003). The univariable analysis revealed that the risk factors of developing IH were old age, female gender, obesity, co-morbid cardiovascular disease, transverse incision for specimen extraction, and perioperative bleeding requiring transfusion. However, on multivariable analysis, specimen extraction site was not significant in developing IH and transfusion requirement was the strongest risk factor.

Conclusions: IH development after MIS is uncommon in Korean patients. Multivariable analysis suggests that specimen extraction site can be flexibly chosen between midline and transverse incisions, with little concern about risk of developing IH. Careful efforts are required to minimize operative bleeding because blood transfusion is a strong risk factor for developing IH.

Keywords: Colorectal cancer; Incisional hernia; Midline incision; Minimally invasive surgery; Specimen extraction; Transverse incision.