The Four Different Types of Internal Hernia Occurring After Laparascopic Roux-en-Y Gastric Bypass Performed for Morbid Obesity: Are There Any Multidetector Computed Tomography (MDCT) Features Permitting Their Distinction?

Abstract

Background Four different types of internal hernias (IH) are known to occur after laparoscopic Roux-en-Y gastric bypass (LRYGBP) performed for morbid obesity. We evaluate multidetector row helical computed tomography (MDCT) features for their differentiation. Methods From a prospectively collected database including 349 patients with LRYGBP, 34 acutely symptomatic patients (28 women, mean age 32.6), operated on for IH immediately after undergoing MDCT, were selected. Surgery confirmed 4 (11.6%) patients with transmesocolic, 10 (29.4%) with Petersen's, 15 (44.2%) with mesojejunal, and 5 (14.8%) with jejunojejunal IH. In consensus, 2 radiologists analyzed 13 MDCT features to distinguish the four types of IH. Statistical significance was calculated (p< 0.05, Fisher's exact test, chi-square test). Results MDCT features of small bowel obstruction (SBO) (n=25, 73.5%), volvulus (n=22, 64.7%), or a cluster of small bowel loops (SBL) (n=27, 79.4%) were inconsistently present and overlapped between the four IH. The following features allowed for IH differentiation: left upper quadrant clustered small bowel loops (p<0.0001) and a mesocolic hernial orifice (p=0.0003) suggested transmesocolic IH. SBL abutting onto the left abdominal wall (p= 0.0021) and left abdominal shift of the superior mesenteric vessels (SMV) (p=0.0045) suggested Petersen's hernia. The SMV predominantly shifted towards the right anterior abdominal wall in mesojejunal hernia (p=0.0033). Location of the hernial orifice near the distal anastomosis (p=0.0431) and jejunojejunal suture widening (p=0.0005) indicated jejunojejunal hernia. Conclusions None of the four IH seems associated with a higher risk of SBO. Certain MDCT features, such as the position of clustered SBL and hernial orifice, help distinguish between the four IH and may permit straightforward surgery.

Bariatric emergencies: current evidence and strategies of management

“…Four types of internal hernia were seen following gastric bypass; Mesenteric, and mesojejunal, Petersons and jejuno-jejunal herniae are identified [46,47], (L2+), [48], (L2++). Obstruction could be due to a mechanical problem or technical error at the anastomosis or from banded gastric bypass operation [49], (L3).…”

A rare cause of gastro-intestinal hemorrhage in a patient with a Roux-en-Y gastric bypass

“…One of the main disadvantages of laparoscopic—compared with open gastric—bypass is the increased incidence of internal hernia, due to the difficulty of properly identifying and closing mesenteric defects. This is also complicated by the specific operative approach, as well as individual surgeons' preference to close all defects to prevent post-operative internal herniation [ 7 ]; such defects include jejunojejunostomy, mesenteric defects, transverse mesocolon defects, and Petersen’s defect (between the Roux limb and the transverse mesocolon). The antecolic procedure removes defects of the mesocolon, considered the most common site of internal herniation following the retrocolic approach.…”

“…A known sequelea of internal hernia after laparoscopic RYGB is small bowel obstruction, with a reported incidence of 0.9–5.0% [ 7 ]. The clinical presentation of an internal hernia ranges from minor abdominal pain requiring elective repair, to profound peritonitis—due to massive segments of ischemic/necrotic bowel—requiring resection.…”

Two similar cases of internal hernia after laparoscopic Roux-en-Y gastric bypass surgery

“…In the majority of cases there are no direct signs of but typical indirect signs like a mesenteric swirl sing, that was present in case 2 12. A CT scan may also help to distinguish between the different hernia types 13. It is important to know that CT scan may also be normal even in symptomatic patients 14…”