Congenital peritoneal encapsulation: A review and novel classification system.

Congenital peritoneal encapsulation (CPE) is a very rare, congenital condition characterised by the presence of an accessory peritoneal membrane which encases a variable extent of the small bowel. It is unclear how CPE develops, however it is currently understood to be a result of an aberrant adhesion in the peritoneal lining of the physiological hernia in foetal mid-gut development. The condition was first described in 1868, and subsequently there have been only 45 case reports of the phenomenon. No formal, systematised review of CPE has yet been performed, meaning the condition remains poorly understood, underdiagnosed and mismanaged. Diagnosis of CPE remains clinical with important adjuncts provided by imaging and diagnostic laparoscopy. Two thirds of patients present with abdominal pain, likely secondary to sub-acute bowel obstruction. A fixed, asymmetrical distension of the abdomen and differential consistency on abdominal palpation are more specific clinical features present in approximately 10% of cases. CPE is virtually undetectable on plain imaging, and is only detected on 40% of patients with computed tomography scan. Most patients will undergo diagnostic laparotomy to confirm the diagnosis. Management of CPE includes both medical management of the critically-unstable patient and surgical laparotomy, partial peritonectomy and adhesiolysis. Prognosis following prompt surgical treatment is excellent, with a majority of patients being symptom free at follow up. This review summarises the current literature on the aetiology, diagnosis and treatment of this rare disease. We also introduce a novel classification system for encapsulating bowel diseases, which may distinguish CPE from the commoner, more morbid conditions of abdominal cocoon and encapsulating peritoneal sclerosis.