Petersen's space hernia: A rare but expanding diagnosis

Abstract

Background

Petersen's space hernia is caused by the herniation of intestinal loops through the defect between the small bowel limbs, the transverse mesocolon and the retroperitoneum, after any type of gastrojejunostomy. The laparoscopic approach facilitates the occurrence of this type of hernia, due to the lack of post-operative adhesions which prevent bowel motility and hence, herniation.

Case report

We report the case of a 46 year-old male submitted to an open antrectomy and vagotomy with a Roux-en-Y reconstruction six-years before, for the treatment of bleeding gastric ulcer.He presented with epigastric abdominal pain radiating to the back and alimentary vomiting with a 3 days evolution, with an episode of hematemesis 2 h before admission. His abdomen was bloated and tender at the epigastric region. The laboratory exams revealed mild leucocytosis and CRP elevation with normal pancreatic tests. The abdominal CT scan revealed an intestinal occlusion. An exploratory laparotomy was performed, disclosing an incarcerated Petersen space hernia of the common limb, with obstruction and dilatation of the biliary limb.

Conclusion

The knowledge of this anatomic post-operative defect and a low threshold for diagnosis are crucial to its management, since its nonspecific clinical and laboratory findings. Early operative intervention is warranted in order to avoid the severe complications of bowel necrosis.

1. Background

Petersen's space Hernia was first described in 1900 by German surgeon, Dr. Walther Petersen.¹ It is an internal hernia, arising after any type of gastrojejunostomy (most frequently after Roux-en-Y anastomosis) and it's boundaries are nowadays described as the transverse mesocolon, the retroperitoneum and the Roux limb mesentery² (Fig. 1).

Fig. 1.

Representation of Petersen space, between the Roux Limb, the Transverse mesocolon and the retroperitoneum.

This type of internal hernia was once very rare and up to 1974, only 178 cases were reported,³ although it's true incidence might be underestimated. It became more frequent in the 1960s and 1970s with the increasing number of antrectomies for peptic ulcer disease. It became again a rare diagnosis with the decline in surgical treatment of peptic ulcer.⁴ However, in the last few years, it is becoming increasingly frequent with the exponential growth in Laparoscopic Gastric Bypass for the treatment of obesity.^5–12 It is even supported by several authors that the use of a laparoscopic approach is a risk factor for this disease, as it prevents the occurrence of post-operative adhesions, which could limit the mobility of the intestinal loops.¹²

We report a case of Petersen space hernia and perform a brief review of the available literature, underlining its “risk factors”, prevention and treatment.

2. Case report

We present a case of a 46 year-old male, submitted to an open antrectomy and vagotomy with Roux-en-Y reconstruction six-years before, for the treatment of a bleeding gastric ulcer.

He was observed in our emergency department, complaining of epigastric abdominal pain radiating to the back and alimentary vomiting with a 3-day evolution. Approximately 2 h before he had had an episode of hematemesis. The patient was diaphoretic but with normal vital signs. His abdomen was bloated and tender at the epigastric region and no other abnormalities were found. The laboratory exams revealed mild leucocytosis and CRP elevation with normal pancreatic enzymes.

He was submitted to an upper digestive endoscopy, which revealed a normal Roux-en-Y gastrojejunal anastomosis in an empty stomach. Progressing through the Roux limb, 30 cm distal to the anastomosis, there was the jejuno-jejunal anastomosis with ischemic and haemorragic mucosa (Fig. 2).

Fig. 2.

Endoscopic view of ischemic mucosa.

The abdominal CT scan revealed a massive distention of the duodenum and an intestinal occlusion occurring over a probable post-operative adhesion (Fig. 3).

Fig. 3.

CT scan coronal slice, showing jejunal occlusion and duodenal distention.

An exploratory laparotomy was performed, disclosing an incarcerated Petersen space hernia of the common limb, with obstruction and dilatation of the biliary limb (Fig. 4).

Fig. 4.

Petersen space hernia. Note the jejunal limb crossing the Petersen space.

The incarcerated bowel was repositioned and there was no irreversible ischemia, no resection being required. The Petersen space was closed with a running suture of Vicryl^® 3/0. The post-operative period was unremarkable and the patient was discharged at the fourth post-op day, remaining asymptomatic at 12 months follow-up visit.

3. Discussion

The transverse colon and mesocolon act as a natural partition between the stomach and the small intestine. Once any type of gastrojejunal anastomosis is constructed, a potential space for internal herniation is created, posterior to the limbs of the small intestine.

The modern descriptions of Petersen's hernia are different^2,13,14 from the original one, of two consecutive cases of internal hernia after loop gastrojejunostomy with a clockwise rotation and herniation of the efferent limb behind the anastomosis.

Modern references in the literature most commonly define the boundaries of the hernia defect to be the transverse mesocolon inferior edge, the mesentery of the alimentary limb and the retroperitoneum (Fig. 1). They are generally used to describe a herniation of small bowel into the space created between the cut edge of the Roux limb mesentery and the transverse mesocolon, being it secondary to a clockwise or an anti-clockwise rotation.^{2,5–9,14–16}

Despite the clear advantages offered by laparoscopic surgery,¹² the increasing rate of laparoscopic Roux-en-Y gastric bypass for the treatment of morbid obesity⁵ has led to an increasing report of small bowel obstruction secondary to internal hernias.¹⁷ The small bowel obstruction after open gastric surgery is more commonly due to adhesions,⁵ and not internal hernias as in this reported case.

The relative lack of adhesions after laparoscopic gastric surgery contributes to the mobility of the small bowel and to the occurrence of internal hernias^12,16 but at the same carries the advantage of allowing its laparoscopic management.¹²

The occurrence of internal herniation after laparoscopic gastric bypass is reported to be 1–4%^6,16 and after open gastric surgery is thought to be rare¹² (less than 1% of cases). However, its real incidence is difficult to determine due to the unspecific diagnosis and occurrence at anytime (from a few days to several years) after surgery¹²; thus requiring a low threshold for early diagnosis, crucial to a correct management.⁹

Several studies have reported that the antecolic placement of the Roux-limb is associated with a lower incidence of internal hernias,^10,11,16 although the inverse has also been reported.⁹ Of all the internal hernias occurring after an antecolic Roux-en-Y, the Petersen space hernia seems to be the most frequent.^8,9

Several authors have suggested the necessity to close all the mesenteric defects with permanent running sutures, in order to diminish the incidence of this complication,^9,12,17 although it seems not to eliminate this risk. After Laparoscopic Roux-en-Y gastric bypass for morbid obesity it is thought that the massive loss of weight and abdominal fat, might widen some small mesenteric defects even after adequate closure at the time of surgery.^6,8

One major challenge with these patients is that the presenting signs, symptoms and radiological examinations may be nonspecific or nondiagnostic.^5,11 The most commonly reported clinical symptoms are abdominal pain (sometimes intermittent due to recurrent herniation) and nausea/vomiting.¹⁶ Abdominal pain is present in almost all patients, often in the epigastric region and with dorsal irradiation.⁸ Nausea or vomiting is present, also in a majority of patients and many have few clinical signs, even in the presence of incarcerated bowel.⁸ However, symptoms might be so sporadic and self-resolving that patients do not complain to their attending surgeon as they think it is “normal” after surgery or results from alimentary excesses.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.^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.^6,16 When bowel obstruction and severe pain are present, emergent surgical exploration is mandatory.¹² Most patients might be treated laparoscopically¹² and the treatment should be directed to the underlying disease, with reduction of the hernia and closure of all the mesenteric defects.⁶ Intestinal resection might be needed if necrosis is seen on surgical exploration.⁶

4. Conclusion

Petersen's space hernia is a forgotten diagnosis for most of surgeons in the last 30 years, due to the diminished frequency of gastrojejunostomies. However, the exponential growth of laparoscopic gastric bypass for the treatment of morbid obesity will increasingly bring to us this kind of complication. The closure of all mesenteric defects might lower its incidence.

The knowledge of this anatomic post-operative defect and a low threshold for diagnosis are crucial to its management, given its nonspecific clinical and laboratory findings. Early operative intervention is warranted in order to avoid the severe complications of bowel necrosis.

Conflicts of interest

The authors report that there are no conflicts of interest.

Funding

None.

Ethical approval statement

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.