Retrospective observational study on the incidence of incisional hernias after reversal of a temporary diverting ileostomy following rectal carcinoma resection with follow-up CT scans.

Background: Wounds resulting from the closure of temporary stomas have a high risk of developing an incisional hernia (IH) with incidences around 30% in studies designed to investigate this outcome. A temporary diverting ileostomy (TDI) is often used in patients after low anterior resection (LAR) for rectal cancer.

Methods: The OSTRICH study is a retrospective cohort study of rectal cancer patients who had a LAR with a reversed TDI and at least one CT scan during follow-up. Two radiologists independently evaluated all abdominal CT scans to diagnose IH at the ileostomy wound and additionally, IH at the laparotomy site.

Results: From the oncological database of rectal cancer patients treated from 2003 till 2012 (n = 317) a cohort of 153 patients that fulfilled the inclusion criteria was identified. Rectal cancer resection was performed by laparoscopy in 53 patients (34.6%) and by laparotomy in 100 patients (65.4%). A total of 17 IH (11.1%) was diagnosed at the former stoma site after a mean follow-up of 2.6 years. Of these, 8 IH were in patients who had a laparoscopic LAR (15.1%) and 9 IH in patients who had an open LAR (9.0%) (Fisher's exact test; p = 0.28). IH on the other abdominal wall incisions was reported in 69 patients (45.1%). Of these, 10 patients underwent laparoscopic rectal surgery (18.9%) and in 59 patients had open rectal surgery (59.0%) (Fisher's exact test; p < 0.0001).

Conclusion: We found a lower number of incisional hernias (11.1%) after reversal of ileostomies than expected from the literature. In contrast to the findings at the ileostomy site, a very high frequency of IH (59.0%) after LAR by laparotomy was found, which was significantly higher than after laparoscopic LAR.