# Small bowel intussusception after Roux-en-Y gastric bypass – A case report

## TL;DR

This case report describes a rare complication of small bowel intussusception following Roux-en-Y gastric bypass surgery and emphasizes the need for prompt surgical intervention.

## Contribution

The paper presents a case of intussusception after Roux-en-Y gastric bypass and discusses its pathophysiology and surgical management.

## Key findings

- Intussusception can occur without a lead point and in both anterograde or retrograde fashion.
- Prompt surgical management is essential, with options including resection, reduction, plication, or reduction and plication.
- The cause is hypothesized to involve interruption of duodenal pacemaker cells and development of ectopic jejunal pacemaker cells.

## Abstract

Roux-en-Y gastric bypass (RYGB) is a common elective bariatric operation performed to facilitate weight loss in patients with obesity. Although generally associated with a low rate of late complications, intestinal intussusception can very rarely occur in patients who have undergone RYGB, with significant clinical consequences. This case reinforces the importance of prompt recognition and surgical intervention in cases of intussusception following RYGB, explores the proposed pathophysiology of intussusception, and highlights the options for surgical intervention.

We report a case of a 52-year-old female presenting with a small bowel obstruction secondary to intussusception in the context of a RYGB performed 8-years previously. Computed tomography (CT) and diagnostic laparoscopy confirmed intussusception of a long segment of the biliopancreatic limb into the Roux limb through the jejuno-jejunal anastomosis. Unable to be reduced laparoscopically, the anastomosis was resected en bloc and refashioned. The patient recovered well, and reported no features of recurrence or other surgical complication at post-operative review.

The aetiology of intussusception following RYGB is unclear, although hypotheses include interruption of duodenal pacemaker cells following transection of the small bowel and consequent development of ectopic jejunal pacemaker cells, increased mobility of the mesentery following extreme weight loss, or the jejunojejunal anastomosis functioning as a transition point. In cases of compromised bowel resection is essential, although the approach in cases of non-compromised bowel is less clear.

The recognition of late RYGB complications is becoming increasingly important in the setting of the increasing prevalence of bariatric surgery. Intussusception is an infrequent but significant complication that requires urgent surgical intervention.

•Small bowel intussusception is an infrequent but clinically significant complication post Roux-en-Y gastric bypass•Intussusception can occur without a lead point, and in both an anterograde or retrograde fashion•Hypothesised to occur due to interruption of duodenal pacemaker cells and development of ectopic jejunal pacemaker cells•Require prompt surgical management, with a role for resection, reduction, plication, or reduction and plication

Small bowel intussusception is an infrequent but clinically significant complication post Roux-en-Y gastric bypass

Intussusception can occur without a lead point, and in both an anterograde or retrograde fashion

Hypothesised to occur due to interruption of duodenal pacemaker cells and development of ectopic jejunal pacemaker cells

Require prompt surgical management, with a role for resection, reduction, plication, or reduction and plication