Petersen’s hernia after gastric by-pass procedure: an increasingly frequent condition in emergency surgery

Introduction: Gastric by-pass is the most frequent surgical procedure for morbid obesity worldwide. Internal hernia (IH) may develop in the Petersen’s space as a consequence of an antecolic Roux-en- Y reconstruction. Symptoms may remain not specific for months before the onset of acute abdomen conditions including mechanical bowel obstruction and intestinal ischemia. Pre-operative diagnosis is mostly based on contrast enhanced abdomen CT scan that shows signs of twisting of superior mesenteric vessels. Materials and methods: We retrospectively reviewed 9 patients (8 females) with Petersen’s IH referred to our institution between January 2015 and March 2018 for acute abdomen. Mean age was 40.7 yr. All of them had received a gastric by-pass procedure with antecolic Roux-en-Y reconstruction meanly 914 days before the clinical manifestation of IH. The mean weight loss after bariatric surgery was 56.6 Kg. Results: In all patients the abdominal contrast enhanced CT scan was positive for twisting of superior mesenteric vessels suggesting the diagnosis of Petersen’ IH. The abdominal cavity was explored laparoscopically with identification of the IH. The herniated loop was gently relieved from the Petersen’ space, the blood supply of the bowel loop was assessed, and the defect was closed with a non-adsorbable interrupted suture. Conversion to open surgery was required in one patient. The course of the patients was uneventful. At follow-up no recurrence was observed. Discussion and conclusions: A high degree of suspicion for Petersen’s IH should be maintained in patients after gastric by-pass surgery with antecolic Roux-en-Y reconstruction. In these patients, an unexplained persistent abdominal pain should be investigated by contrast enhanced CT scan. The laparoscopic approach is safe and effective and it allows to relieve the herniated bowel loop and to close the mesenteric defect.