Petersen’s hernia as a complication of bariatric surgery: CT findings

Abstract

Referrals for bariatric surgery have currently increased due to the need for more effective interventions in the management of severely obese patients. The Roux-en-Y gastric bypass is currently one of the preferred procedures, and internal hernias are the main causes of late postoperative complication. Petersen's hernia is a less common finding in most published papers compared to transmesocolic hernia, however, it seems to be increasing in incidence (in our service, eight cases which have been tomographic diagnosed in 2 years, were confirmed by laparoscopic surgery). The clinical findings are not specific, usually with abdominal pain, associated or not with abdominal distention and vomiting. In this context, imaging exams have an important role in the early diagnosis and surgery of this condition, with multislice computed tomography being the most accurate method. The aim of this pictorial essay is to the demonstrate the main CT findings associated with Petersen's hernia in patients who underwent Roux-en-Y gastric bypass.

Petersen's space hernia: A rare but expanding diagnosis

“…12 Abdominal CT scan should be obtained in all patients with a gastro-jejunal anastomosis (especially if after laparoscopic surgery) complaining of vague abdominal pain/discomfort not otherwise explained, especially in the presence of unremarkable clinical and laboratory findings. 18 Abdominal multi-slice CT scan is the most accurate diagnostic procedure 16,19 and the most frequent findings are abdominal distention in the upper abdomen, herniation of the intestinal loop segment above the gastric level, rotation of the mesenteric vessels, mesenteric fat haziness, anterior and right displacement of the ligament of Treitz and distal ileum coursing downwards in the left hypochondrium. 19 However, the study of these patients might not be complete without an exploratory laparoscopy, since up to 20-30% of these patients will have "normal laboratory and radiological work-up", in the presence of an internal hernia.…”

“…18 Abdominal multi-slice CT scan is the most accurate diagnostic procedure 16,19 and the most frequent findings are abdominal distention in the upper abdomen, herniation of the intestinal loop segment above the gastric level, rotation of the mesenteric vessels, mesenteric fat haziness, anterior and right displacement of the ligament of Treitz and distal ileum coursing downwards in the left hypochondrium. 19 However, the study of these patients might not be complete without an exploratory laparoscopy, since up to 20-30% of these patients will have "normal laboratory and radiological work-up", in the presence of an internal hernia. 12,16 The risk of necrosis of long segments of small bowel underlines the absolute need for an early diagnosis and intervention, due to the associated increase in morbidity and mortality.…”

A Large Refilling Cystic Lesion In A Gastric Bypass Patient

“…It is one of the rarest types and can be retrocolic Petersen or antecolic Petersen, based on where the Roux loop is placed ( Figure 3 ). 1 …”

“…Petersen's hernia is one of the rarest, and occurs through the potential gap between the jejunal mesentery and mesocolon behind the alimentary limb. 1 Prior case reports have described patients with acute abdominal pain, marked hyperamylasemia, and palpable abdominal masses due to afferent loop obstruction 5-15 years after Billroth II gastrectomy, but were initially diagnosed as pancreatic pseudocysts, obstructive jaundice, and pancreatitis. 2 - 4 With the growing number of bariatric surgeries, physicians should be aware of internal hernia complications to avoid misdiagnosis and delayed management.…”

Imaging Postoperative Abdominal Hernias: A Review with a Clinical Perspective

“…Herniated bowel loops are more commonly seen in the left upper quadrant. 16 Unlike the J-J hernia, here the colon and/or the Roux loop of jejunum is seen around the hernial orifice. 7…”