https://orcid.org/0009-0000-1662-3905
Abstract
Abdominal cocoon syndrome, also called idiopathic sclerosing-encapsulating peritonitis, is a rare cause of intestinal obstruction in which bowel loops are enclosed by a fibrocollagenous membrane. Diagnosis is often delayed because symptoms are nonspecific and many cases are confirmed only at operation. We report a case of a 65-year-old man in Saudi Arabia who presented with vomiting, abdominal distension, anorexia, constipation, and colicky epigastric and periumbilical pain. Computed tomography showed high-grade small bowel obstruction at the distal ileum with features of encapsulating peritoneal sclerosis. Diagnostic laparoscopy was converted to open laparotomy because of complex adhesions and a mass involving the distal ileum, right colon, sigmoid colon, and bladder. He underwent adhesiolysis, right hemicolectomy, and ileocolic anastomosis. Recovery was complicated by intra-abdominal collections requiring image guided drainage. He recovered clinically and remained well at follow-up.
Introduction
Sclerosing-encapsulating peritonitis is an uncommon fibroinflammatory disorder in which the bowel is partially or completely surrounded by a dense membrane [1, 2]. The idiopathic form is known as abdominal cocoon syndrome, whereas secondary disease is associated with causes such as peritoneal dialysis, tuberculosis, previous peritonitis, abdominal surgery, malignancy, autoimmune disease, and intraperitoneal therapy [2, 3]. The condition was first described as peritonitis chronica fibrosa incapsulata by Owtschinnikow in 1907, and the term abdominal cocoon was later introduced by Foo et al. in 1978 [4, 5]. Patients usually present with recurrent or acute bowel obstruction, abdominal pain, distension, nausea, vomiting, anorexia, and weight loss, which overlap with more common surgical disorders [6, 7]. Computed tomography (CT) can suggest the diagnosis by showing clustered small bowel loops enclosed by a soft tissue membrane, sometimes with ascites, calcification, or bowel wall thickening [8, 9]. To further highlight this uncommon entity, we report a case of abdominal cocoon syndrome in Saudi Arabia presenting with high-grade obstruction and postoperative intra-abdominal collection.
Case report
A 65-year-old man presented to the emergency department with 1 day of colicky epigastric and peri-umbilical pain, vomiting, abdominal distension, anorexia, and constipation followed by loose stool. His medical history included diabetes mellitus and hypertension. His surgical history included left double J ureteric stent insertion for renal stones, laparoscopic cholecystectomy, and surgery for testicular varices. Abdominal examination showed a distended, tender abdomen with right lower quadrant fullness and no peritoneal signs, and digital rectal examination revealed an empty rectum. White cell count was 16.1 × 109/l and lactate was 4.3 mmol/l.
CT of the abdomen and pelvis showed high-grade small bowel obstruction at the distal ileal loops, with features of encapsulating peritoneal sclerosis and no ischemia (Fig. 1). He underwent diagnostic laparoscopy, which showed markedly dilated small bowel from the duodenojejunal flexure to 30 cm proximal to the ileocecal valve. A cystic mass arising from the small bowel created dense adhesions to the posterior pelvic wall, bladder, and sigmoid colon; given the limited safe dissection planes and risk of visceral injury laparoscopically, the procedure was converted to open laparotomy (Fig. 2). The mass was dissected from the sigmoid colon and bladder without injury. Right colon mobilization was performed, followed by resection of the mass with the right colon and ileocolic anastomosis. Given the dense adhesions to the bladder, intraoperative cystoscopy and bilateral retrograde pyelography were performed to assess urinary tract injury, which showed no evidence of injury.
Contrast enhanced CT of the abdomen showing fluid-filled dilated small bowel loops measuring up to 4.1 cm, with transition at the distal ileal loops at the site of encapsulating peritoneal sclerosis. No pneumatosis, free air, or vascular occlusion is seen. (a) Axial image showing multiple fluid-filled, dilated small bowel loops measuring up to 4.1 cm in diameter. (b) Axial image demonstrating the transition point (arrow) at the distal ileum with clustered, tethered small bowel loops, and surrounding peritoneal thickening. (c) Sagittal reconstruction showing conglomeration of small bowel loops within a fibrotic peritoneal sac, with the distal ileum as the site of transition. (d) Axial pelvic image demonstrating marked peritoneal thickening and encapsulation measuring up to 6.3 cm in thickness.
Intra-operative findings of abdominal cocoon syndrome (encapsulating peritoneal sclerosis). (a) Laparotomy incision showing the thick fibrous membrane encasement of the bowel, with small bowel loops clustered and tethered together by a thick, dense fibrous band (arrow) forming the peritoneal “cocoon.” (b) Close-up view through the laparotomy incision demonstrating the thick, glistening white fibrous membrane (arrow) encasing, and constricting the underlying bowel loops.
The early postoperative course was satisfactory apart from transient acute kidney injury related to intravascular volume depletion and hypertension requiring medication adjustment. Histopathology demonstrated a dense, markedly hypocellular fibrocollagenous peritoneal rind surrounding the bowel, with extensive hyalinization, and no evidence of malignancy, consistent with sclerosing peritonitis (Fig. 3). He was discharged on postoperative day 10 while tolerating diet and passing stool.
Histologic features of sclerosing peritonitis. (a) H&E, low-power whole-section view showing a folded bowel segment enclosed by an external dense fibrocollagenous peritoneal rind (scale bar = 5 mm). (b) H&E, low-power view showing extensive plaque-like, markedly hypocellular fibrocollagenous sclerosis extending through adjacent fibroadipose tissue (scale bar = 2 mm). (c) H&E, intermediate-power view showing dense, markedly paucicellular hyalinized collagen containing sparse bland fibroblastic-type spindle cells (scale bar = 400 μm). (d) H&E, higher-power view demonstrating sparse bland spindle cells within dense collagen, a focal lymphocyte-predominant inflammatory band, and capillary congestion with extravasated erythrocytes (scale bar = 200 μm).
Ten days after discharge, he returned with abdominal pain near the laparotomy wound associated with nausea and repeated bilious vomiting. Abdomen CT showed postoperative, rim enhancing intra-abdominal collections, inflammatory peritoneal changes, and low-grade small bowel obstruction, with transition at the proximal jejunum, attributed to mass effect and underlying sclerosing peritoneal disease. He underwent fluoroscopic and ultrasound guided drainage and debridement. Cultures were negative for Clostridioides difficile. Follow-up imaging showed reduction of the collections, and he completed the antibiotic course. Upon outpatient review, he was tolerating normal diet, passing stool, and had no abdominal pain. Rheumatology assessment showed negative antinuclear antibody and no evidence of systemic rheumatological disease.
Discussion
Abdominal cocoon syndrome is a rare entity, and it poses a diagnostic challenge due to its nonspecific clinical features. In a review of 169 primary cases, small bowel obstruction and intermittent abdominal pain were the most frequent presentations, and only a minority were diagnosed before surgery [10]. The syndrome is classified by the extent of encasement: type I involves part of the small bowel, type II involves the whole small bowel and type III extends to other organs such as the colon, appendix, stomach, liver, ovaries, or bladder [2, 10]. The presented case is consistent with type I disease because the process involved part of the small bowel which is the distal ileum.
Contrast enhanced CT is the most useful preoperative investigation when abdominal cocoon syndrome is suspected. Reported findings include congregated small bowel loops, a surrounding membrane, bowel obstruction, peritoneal or mesenteric thickening, ascites, loculated fluid, calcification, and lymphadenopathy [8, 9, 11]. In this patient, CT identified distal ileal obstruction and encapsulating peritoneal sclerosis, allowing operative planning before definitive confirmation at surgery.
Management of abdominal cocoon syndrome depends on symptoms and severity. Conservative treatment with bowel rest, nasogastric decompression, and nutritional support may be suitable for mild or incomplete obstruction [2]. Surgical management is preferred for persistent or high-grade obstruction and usually consists of careful membrane excision and adhesiolysis [6, 12]. Bowel resection should be limited to nonviable bowel or segments that cannot be safely separated, as extensive resection increases the risk of short bowel syndrome and anastomotic complications [2, 6]. In this case, right hemicolectomy was required because of the mass effect and involvement of the right colon.
Postoperative small bowel obstruction, collections, fistula, perforation, and short bowel syndrome are recognized complications after surgery for abdominal cocoon syndrome [6, 13]. The patient developed intra-abdominal collections and low grade obstruction soon after discharge, but improved after image guided drainage and antibiotics.
Conclusion
This case highlights the value of pre-operative CT in guiding the surgical management, the readiness to convert laparoscopy to open surgery when adhesions are complex, selective bowel resection when necessary, and close postoperative follow-up to detect potential complications.
Conflicts of interest
No conflict of interest.
Funding
None declared.
Patient consent
Written patient consent for publication was obtained from the patient before submission.
