Internal hernia following laparoscopic anterior resection for cancer: higher prevalence than expected of an under-reported complication

Abstract

Internal hernia (IH) after laparoscopic colorectal surgery is a potentially severe complication. It may go undiagnosed in patients having their abdominal CT scan during oncologic follow-up. We evaluated the occurrence of IH on CT scans after laparoscopic curative resection for rectal cancer (LRRC) and routine closure of the mesenteric defect. Data from 189 consecutive patients undergoing elective curative LRRC in a 14-year period (June 2005-june 2019) were prospectively collected. Only patients with abdominal CT scans, performed as routine oncologic follow-up, between 3months and 7years post-operatively were included in the study and reviewed by a surgeon and a radiologist. A total of 161 patients were eligible for the study with a median age of 69years (IQR: 59-77) at surgery. They had abdominal follow-up CT scans at a median of 39.5months (IQR: 12.8-62.7) after surgery. The prevalence of IH was 11.2% (18/161 patients). Of the 18 patients, 15 (83.3%) were fully asymptomatic, 2 (11.1%) reported chronic abdominal discomfort (including mostly nausea and colicky pain) during their oncologic follow-up (however, IH was not suspected neither prompted additional investigations), and 1 (5.6%) was reoperated elsewhere for IH and acute small bowel obstruction. IH following LRRC is not uncommon, with a prevalence > 10% in our experience. Most of these patients remain fully asymptomatic, but in a few patients, IH might be responsible for some symptoms or require reoperation. Awareness of this complication is important, given the potential risk of acute small bowel obstruction.