# Petersen’s Hernia Following Laparoscopic Roux-en-Y Gastric Bypass: A Retrospective Case Series of Six Patients

## TL;DR

This study reports six cases of Petersen’s hernia after gastric bypass surgery, highlighting diagnostic challenges and successful surgical outcomes.

## Contribution

The paper provides a detailed case series of Petersen’s hernia following LRYGB, emphasizing its delayed presentation and management strategies.

## Key findings

- Petersen’s hernia occurred between 20 days and 12 years after gastric bypass surgery.
- Computed tomography with the 'swirl sign' was the most common radiological indicator.
- All patients had successful surgical repair with no bowel resection or recurrence.

## Abstract

Petersen’s hernia is a rare but potentially life-threatening complication following laparoscopic Roux-en-Y gastric bypass (LRYGB). Its clinical presentation is often nonspecific, and radiological findings may be subtle, contributing to diagnostic delays. This retrospective study included all patients diagnosed and surgically treated for Petersen’s hernia at Unidade Local de Saúde de Braga, EPE, between January 2023 and June 2025. A total of six patients (three men, three women) were identified, with a mean age of 44 years (range: 31-64 years). All patients had previously undergone LRYGB. The interval between primary surgery and hernia presentation ranged from 20 days to 12 years. Abdominal pain was a universal symptom, frequently accompanied by nausea or vomiting (67%). Computed tomography (CT) suggested internal hernia in five cases (83%), with the swirl sign being the most commonly observed feature. Surgical exploration was performed via laparoscopy in four cases and laparotomy in two. Petersen’s hernia was confirmed in all patients, with no need for bowel resection. All defects were closed using double-layer, non-absorbable barbed sutures. The mean length of hospital stay was 4.3 days (range: 2-6 days), and no postoperative complications, readmissions, or symptom recurrence were observed during follow-up. Despite advances in imaging, Petersen’s hernia remains a diagnostic challenge that may present years after bariatric surgery. High clinical suspicion and prompt surgical exploration are essential. Routine closure of mesenteric defects and management by bariatric-trained surgeons appear to be critical in minimizing morbidity and improving outcomes.