Via Research Recognition Day Program VCOM-Carolinas 2025

Case Reports

CONGENITAL PERITONEAL ENCAPSULATION - A RARE MALFORMATION WITH DIAGNOSTIC CHALLENGES: A CASE REPORT AND REVIEW OF LITERATURE

Alison Schultz, BA 1 , Paul Creger, DO 2 , Trey Mathews, MD 2 , Todd Minshall, MD 2 , Kristine Lombardozzi, MD 1,2 1. Edward Via College of Osteopathic Medicine, Spartanburg, SC. 2. Spartanburg Medical Center, Department of Surgery, Spartanburg, SC.

Introduction

Discussion

References • The diagnosis of CPE prior to surgery is clinically challenging. • Patients can present symptomatically or asymptomatically and often have normal vitals and nonspecific laboratory values. • Abdominal findings on physical exam are nonspecific, with abdominal tenderness being the most common. • Two distinct physical findings of CPE have been described: 1) fixed asymmetrical distention of the abdomen on physical exam, and/or 2) difference in consistency of abdominal wall to palpation, with firmer areas signifying the denser accessory peritoneal sac (2). • CT imaging is regarded as the most sensitive imaging modality to identify CPE. The most specific finding of CPE is coined the “helix sign” (3). CT imaging, however, often fails to identify the accessory sac and should only be used as an adjunct in diagnosis. • Definitive diagnosis is made intraoperatively with gross visualization of a peritoneal-like sac encapsulating the small intestines and confirmed by histology. • Treatment involves the surgical excision of the accessory sac and adhesiolysis of the sac’s fixation points and any identifiable bands. • Prognosis is excellent. Conclusions Our case report illustrates the lack of associated co-morbidities, minimal symptomatology and non-specific imaging findings that can be observed at the time of presentation with bowel obstruction from CPE. Clinicians should keep a wide differential that includes CPE when treating a patient with no identifiable cause of long-standing abdominal pain or acute bowel obstruction. 1. Dave A, McMahon J, Zahid A. Congenital peritoneal encapsulation: A review and novel classification system. World J Gastroenterol . 2019;25(19):2294-2307. doi:10.3748/wjg.v25.i19.2294. 2. Naraynsingh V, Maharaj D, Singh M, Ramdass MJ. Peritoneal encapsulation: a preoperative diagnosis is possible. Postgrad Med J. 2001;77(913):725-726. doi:10.1136/pmj.77.913.7 3. Mitrousias V, Alexiou E, Katsanas A, Batzalexis K, Germanos S: The helix sign in the peritoneal encapsulation syndrome: a new sign in a rare cause of bowel obstruction? J Gastrointestin Liver Dis. 2015, 24(2):144. doi: 10.15403/jgld.2014.1121.242.hlx. PMID: 26114169. Special thanks to the Pathology Department at Spartanburg Medical Center for their contribution of the patient’s histology. Acknowledgements

• Congenital Peritoneal Encapsulation (CPE) is a rare, but significant cause of abdominal pain and small bowel obstruction. This congenital malformation involves the small intestine being enclosed within an accessory double-layered peritoneal sac. • Patients with CPE are often asymptomatic and are diagnosed incidentally. Most patients have noncontributory medical history and no previous abdominal surgeries. • Less than 60 cases of this malformation have been described in literature, with an average presenting age of 40.8 years old and a 5:3 male predominance (1). • CPE is a possible cause of abdominal pain and small bowel obstruction which, when identified, carries an excellent prognosis with surgical treatment. • A 34-year-old male with no previous medical history presented with three days of abdominal pain, nausea, and vomiting. • He was hemodynamically stable. • His laboratory evaluation demonstrated mild leukocytosis on arrival with WBC of 10.4 10E3/ μ L. All other lab values were normal, including lactate of 0.7 mmol/L (ref: 0.5-2.2 mmol/L). • Physical exam: Abdomen was minimally distended and diffusely tender with focal peritonitis in the right lower quadrant. • Computed tomography (CT) imaging was suggestive of closed loop small bowel obstruction. • The patient’s condition worsened when he threw up PO contrast for an abbreviated small bowel follow-through. He was taken to the OR for exploratory laparotomy. • Upon entry into the abdomen, the operative team identified a second layer of peritoneum encasing the entirety of the small bowel. The additional peritoneal sac was excised, which freed adhesive bands overlying the Ligament of Treitz and terminal ileum. • Pathology: Findings were compatible with an intraperitoneal sac. • The patient recovered well and had return of bowel function on post-operative day (POD) 1. He was discharged on POD 3. He presented asymptomatic at his 2-week follow-up. Case Presentation

Figure 1. Peritoneal encapsulation of the small bowel visualized intraoperatively.

Figure 2. H&E staining of accessory peritoneal membrane at 4x magnification demonstrating peritoneal sac with vascular congestion.

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