Abdominal Cocoon Syndrome is a Rare Cause of Mechanical Intestinal Obstructions: A Report of Two Cases

Background

Abdominal cocoon syndrome (ACS) is described as total or partial fibrotic capsulation of the abdominal organs. It is first described by Foo et al. in 1978 [1]. ACS is also known as sclerosing encapsulating peritonitis, primary sclerosing peritonitis, and idiopathic sclerosing peritonitis [2]. It has 2 types: primary (idiopathic) and secondary. The secondary type is seen in patients with peritoneal dialysis, peritonitis, previous abdominal surgery, sarcoidosis, and tuberculosis [3]. The prevalence of ACS is unknown, but among peritoneal dialysis patients the prevalence is 1.4–7.3%.

We here present 2 idiopathic ACS cases treated successfully.

Case Reports

CASE 1:

A 30-year-old male patient presented with nausea, vomiting, and abdominal pain which started a few days before. He had a clinical history of several attacks of abdominal pain before, but they resolved spontaneously. The patient had no history of previous abdominal operations or medication.

On clinical examination, the abdomen was tender and distended. Plain abdominal X-rays showed small bowel type air-fluid levels and abdominal CT showed dilatation and wall thickness in the terminal ileum (Figure 1). Findings of laboratory studies were within normal limits. Exploratory laparotomy was decided upon with a pre-operative diagnosis of ‘acute mechanical intestinal obstruction’.

At laparotomy, the internal herniated ileum was found encased in a cocoon-like fibrotic tissue with a diameter of nearly 20 cm. We cut the fibrous membrane and the small bowel loosened. Circulation of the bowel segment was intact; therefore, no resection was needed during the operation. On the fourth post-operative day the patient was discharged.

CASE 2:

A 47-year-old male patient was admitted to our hospital, complaining of constipation, nausea, and vomiting for the past 3 days. He had no significant medical and clinical history. The patient had no history of previous abdominal operations or medication.

Only distension of the abdomen was observed during clinical examination. Plain abdominal X-rays showed air-fluid levels and abdominal CT showed the clustered terminal ileum and cecum, with dilatation at the proximal parts. Findings of laboratory studies were within normal limits. Exploratory laparotomy was performed.

At laparotomy, the internal herniated ileum and cecum were found in a cocoon-like fibrotic tissue with a diameter of nearly 10 cm (Figure 2). The fibrous membrane cut and bowel segments loosened. Circulation of the bowel segment was intact; therefore, no resection was needed during the operation. On the fifth post-operative day the patient was discharged without any complications.

Discussion

ACS was first defined by Foo et al. in 1978. Despite various hypotheses, the etiology remains unknown. Abdominal cocoon is mostly seen in young girls living in tropical and subtropical regions [1]. However, our 2 patients were middle-aged males. ACS is a rare syndrome that mostly affects the small bowel. In this syndrome there is intra-abdominal fibrosclerosis and peritoneal adhesions that surround the bowel, creating a sac or cocoon that causes acute or chronic intestinal obstruction [4]. ACS was reported in beta blockers users, peritoneal dialysis, peritoneal shunting, recurrent peritoneal irritation and peritonitis, intraperitoneal chemotherapy, and cirrhosis, but mostly it is an idiopathic disease.

The clinical presentation of abdominal cocoon syndrome generally occurs as acute abdomen and intestinal obstruction. Preoperative diagnosis of ACS is difficult. Radiological findings, especially CT findings, may suggest the diagnosis but final diagnosis is generally by surgery, as confirmed by the ACS literature and summarized in Table 1.

Retroperitoneal fibrosis (also known as Ormond disease) is a rare syndrome featuring fibrosclerosis of the tissue in the retroperitoneum, often leading to encasement of the ureters, such as encasement of the intestines in cocoon syndrome. The difference between Ormond disease and ACS is the location. Retroperitoneal fibrosis is treated with glucocorticoids. If there is ureteral obstruction, stent or surgery is indicated [5].

Yip and Lee [6] suggested 4 clinical characteristics to be aware of in preoperative diagnosis: a) Young female patients with no obvious cause of intestinal obstruction; b) Medical history of similar episodes and spontaneously relief of symptoms; c) Presentation with symptoms of intestinal obstruction but absence of severe abdominal distention; d) Presence of palpable, soft, non-tender abdominal mass. We saw intestinal obstruction in both cases and similar episodes in the first case. Therefore we cannot always rely exclusively on the characteristics described by Yip and Lee.

Abdominal x-ray and ultrasonography does not help to distinguish ACS from other diseases. CT scan may be helpful in differential diagnosis. Recognition of fibrous membrane surrounding the bowel loops is a typical radiological finding of ACS [7].

Early preoperative diagnosis and treatment of the syndrome is vital for the circulation of the encaged bowel segments and for preventing the risk of strangulation.

Treatment options suggested for ACS are resection of the capsule, partial membrane resection, intestinal resection and primary anastomosis (if strangulated), and resection and creation of a stoma (if there is a perforation and fecal contamination). If the resection has to be done, a stoma is highly recommended.

Conclusions

Abdominal cocoon syndrome is a rare disease and is difficult to diagnose. Here, we report our experience with 2 patients complaining of mechanical intestinal obstruction signs. Recognition of this entity and awareness of the typical radiological findings may aid in proper management.