Unraveling the enigma of sclerosing encapsulating peritonitis: a comprehensive review

Abstract

Sclerosing encapsulating peritonitis (SEP) is a rare but serious condition characterized by the progressive formation of a dense fibrous sheath encasing the small bowel within the peritoneal cavity. This review provides a comprehensive overview of the current understanding of SEP, focusing on its etiology, clinical presentation, diagnostic modalities, and management strategies. SEP can be classified into primary and secondary forms, each with distinct etiologies and treatment approaches. Primary SEP typically presents with acute or subacute bowel obstruction symptoms, necessitating surgical intervention to excise the fibrous sheath and relieve the obstruction. Secondary SEP often occurs in patients undergoing peritoneal dialysis, with cessation of dialysis being a key component of management. Medical treatments, including corticosteroids, immunosuppressive agents, and nutritional support, may complement surgical intervention, particularly in cases of secondary SEP. Advanced imaging techniques and personalized medicine approaches show promise in improving diagnostic accuracy and tailoring treatment strategies to individual patients. Future research directions include investigating targeted pharmacological therapies, exploring minimally invasive surgical techniques, and conducting long-term follow-up studies to evaluate treatment efficacy and disease recurrence. Multidisciplinary care teams play a crucial role in the comprehensive management of SEP, emphasizing collaboration among various specialties to optimize patient outcomes.

Keywords: Abdominal cocoon; Immunosuppressive agents; Peritoneal dialysis; Peritoneal diseases; Peritoneal fibrosis.

Fig. 1.

The categorizations of primary sclerosing encapsulating peritonitis (SEP) as (A) type I, (B) type II, and (C) type III. In type I and II cases, the membrane (depicted in gray) encapsulates a portion and the entirety of the small intestine, respectively. Type III SEP is characterized by a membrane (depicted in gray) encompassing the entire small bowel along with additional organs, such as the ovaries and colon. Illustration by Kraipop Wongwaiyut. Illustration by Kraipop Wongwaiyut.

Fig. 2.

Global distribution of primary sclerosing encapsulated peritonitis.

Fig. 3.

Sex and age distribution of primary sclerosing encapsulated peritonitis.

Fig. 4.

Primary symptoms of primary sclerosing encapsulated peritonitis in 169 cases.

Fig. 5.

Ultrasound examinations of the abdominal region in cases of primary sclerosing encapsulated peritonitis reveal widespread intestinal distension accompanied by the presence of ascites. (A) Distended small intestine. (B) Interloop ascites.

Fig. 6.

Whole-abdomen computed tomography with oral and intravenous contrast. (A) Thick membrane surrounding the small intestine. (B) Stacking dilated small bowel loops inside a thick membrane-like sac.

Fig. 7.

The ileum shows acute transmural hemorrhagic infarction (hematoxylin-eosin, original magnification ×20). The mucosa loses its epithelial cells with hemorrhage. The submucosal layer shows congested vessels. The muscularis propria shows smooth muscles with degenerated nuclei. The serosa shows fibrosis.

Fig. 8.

Areas of fibrosis with hemorrhage are observed in the mesentery, serosa of the vermiform appendix, mesoappendix, and peritoneum (hematoxylin-eosin, original magnification ×100). These areas are composed of fibroblasts, spindle-shaped cells with oval-shaped nuclei, with small new vessel formations are demonstrated among the thick pink collagenous fibers and scattered a small number of chronic inflammatory cells.

Fig. 9.

Treatment options for primary sclerosing encapsulated peritonitis in the 169 symptomatic cases.