Sclerosing encapsulating peritonitis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Contributors: Cafer Zorkun M.D., PhD.

Synonyms and Related Keywords: Abdominal cocoon, sclerosing peritonitis, encapsulating peritonitis, peritonitis chronica fibrosa incapsulata. ^[1]

Overview

Sclerosing encapsulating peritonitis (SEP) is a rare benign cause of acute or subacute small bowel obstruction. It is characterized by total or partial encasement of the small bowel within a thick fibrocollagenous membrane.

Etiology

Sclerosing encapsulating peritonitis can be idiopathic or mainly secondary to chronic ambulatory peritoneal dialysis, peritoneovenous or ventriculoperitoneal shunts, or treatment with practolol.
Various abdominal disorders such as tuberculosis, sarcoidosis, familial mediterranean fever, gastrointestinal malignancy, protein S deficiency, liver transplantation, fibrogenic foreign material and luteinized ovarian thecomas are the other rare causative factors.

Differential Diagnosis

Sclerosing encapsulating peritonitis may be confused with congenital peritoneal encapsulation, which is characterized by a thin accessory peritoneal sac surrounding the small bowel. This asymptomtic condition is generally found incidentally during unrelated surgery and does not fit with the clinical or imaging findings in this group of patients.

**Differentiating sclerosing encapsulating peritonitis from other causes of peritonitis**
Disease		Prominent clinical findings	Lab tests	Tratment
Primary peritonitis	Spontaneous bacterial peritonitis	Absence of GI perforation, most closely associated with cirrhosis and advanced liver disease. Presents with abrupt onset of fever, abdominal pain, distension, and rebound tenderness.	Most have clinical and biochemical manifestations of advanced cirrhosis or nephrosis like leukocytosis,hypoalbuminemia, Prolonged prothrombin time. SAAG >1.1 g/dL, increased serum lactic acid level, or a decreased ascitic fluid pH (< 7.31) supports the diagnosis. Gram staining reveals bacteria in only 25% of cases. Diagnosed by analysis of the ascitic fluid which reveals WBC > 500/ML, and PMN >250cells/ml. Culture of ascitic fluid inoculated immediately into blood culture media at the bedside usually reveals a single enteric organism, most commonly Escherichia coli, Klebsiella, or streptococci.	Once diagnosed,it is treated with Ceftriaxone.
	Tuberculous peritonitis	Seen in 0.5% of new cases of tuberculosis particularly in young women in endemic areas as a primary infection. Presents with abdominal pain and distension, fever, night sweats, weight loss, and altered bowel habits.	Ascites is present in about half of cases. Abdominal mass may be felt in a third of cases. The peritoneal fluid is characterized by a protein concentration > 3 g/dL with < 1.1 g/dL SAAG and lymphocyte predominance of WBC. Definitive diagnosis in 80% of cases is by culture. Most patients presenting acutely are diagnosed only by laparotomy.	Combination antituberculosis chemotherapy is preferred in chronic cases.
	Continuous Ambulatory Peritoneal Dialysis (CAPD peritonitis)	Peritonitis is one of the major complications of peritoneal dialysis & 72.6% occurred within the first six months of peritoneal dialysis. Historically, coagulase-negative staphylococci were the most common cause of peritonitis in CAPD, presumably due to touch contamination or infection via the pericatheter route. Treatment for peritoneal dialysis-associated peritonitis consists of antimicrobial therapy, in some cases catheter removal is also warranted. Additional therapies for relapsing or recurrent peritonitis may include fibrinolytic agents and peritoneal lavage. Most episodes of peritoneal dialysis-associated peritonitis resolve with outpatient antibiotic treatment.	Majority of peritonitis cases are caused by bacteria (50%-due to gram positive organisms, 15% to gram negative organisms,20% were culture negative.2% of cases are caused by fungi, mostly Candida species. Polymicrobial infection in 4%.Exit-site infection was present in 13% and a peritoneal fluid leak in 3 % and M.tuberculosis 0.1%.	Initial empiric antibiotic coverage for peritoneal dialysis-associated peritonitis consists of coverage for gram-positive organisms (by vancomycin or a first-generation cephalosporin) and gram-negative organisms (by a third-generation cephalosporin or an aminoglycoside). Subsequently, the regimen should be adjusted based on culture and sensitivity data. Cure rates are approximately 75%.
Secondary peritonitis	Acute bacterial secondary peritonitis	Occurs after perforating, penetrating, inflammatory, infectious, or ischemic injuries of the GI or GU tracts. Most often follows disruption of a hollow viscus?chemical peritonitis?bacterial peritonitis(polymicrobial, includes aerobic gram negative {E coli, Klebsiella, Enterobacter, Proteus mirabilis} and gram positive { Enterococcus, Streptococcus} and anaerobes {Bacteroides, clostridia}). Presents with abdominal pain, tenderness, guarding or rigidity, distension, free peritoneal air, and diminished bowel sounds. Signs that reflect irritation of the parietal peritoneum resulting ileus. Systemic findings include fever, chills or rigors, tachycardia, sweating, tachypnea, restlessness, dehydration, oliguria, disorientation, and, ultimately, refractory shock.		Peritoneal lavage, Laparoscopy are the treatment of choice.
Secondary peritonitis	Biliary peritonitis	Most often seen in cases of rupture of pathological gallbladder or bile duct or cholangitic abscess or secondary to obstruction of the biliary tract. Seen in alcoholic patients with ascites.
Tertiary peritonitis		Persistence or recurrence of intraabdominal infection following apparently adequate therapy of primary or secondary peritonitis. Associated with high mortality due to multi organ dysfunction. It presents in a similar way as other peritonitis but is recognized as an adverse outcome with poor prognosis.	Enterococcus, Candida, Staphylococcus epidermidis, and Enterobacter being the most common organisms.	Characterized by lack of response to appropriate surgical and antibiotic therapy due to disturbance in the hosts immune response.
Familial Mediterranean fever (periodic peritonitis, familial paroxysmal polyserositis)		Rare genetic condition which affects individuals of Mediterranean genetic background. Etiology is unclear. Presents with recurrent bouts of abdominal pain and tenderness along with pleuritic or joint pain. Fever and leukocytosis are common.		Colchicine prevents but does not treat acute attacks.
Granulomatous peritonitis		A rare condition caused by disposable surgical fabrics or food particles from a perforated ulcer, eliciting a vigorous granulomatous (delayed hypersensitivity) response in some patients 2-6 weeks after laparotomy. Presents with abdominal pain, fever, nausea and vomiting, ileus, and systemic complaints, mild and diffuse abdominal tenderness.	Diagnosed by the demonstration of diagnostic Maltese cross pattern of starch particles.	The disease is self-limiting. Treated with corticosteroids or anti-inflammatory agents.
Sclerosing encapsulating peritonitis		Seen in conditions associated with long term peritoneal dialysis, shunts like VP shunts, history of abdominal surgeries, liver transplantation. Symptoms include nausea, abdominal pain, diarrhea, anorexia, bloody ascites.
Intraperitoneal abscesses		Most common etiologies being Gastrointestinal perforations, postoperative complications, and penetrating injuries. Signs and symptoms depend on the location of the abscess within the peritoneal cavity and the extent of involvement of the surrounding structures. Diagnosis is suspected in any patient with a predisposing condition. In a third of cases it occurs as a sequela of generalized peritonitis. The pathogenic organisms are similar to those responsible for peritonitis, but anaerobic organisms occupy an important role. The mortality rate of serious intra-abdominal abscesses is about 30%.	Diagnosed best by CT scan of the abdomen.	Treatment consists of prompt and complete CT or US guided drainage of the abscess, control of the primary cause, and adjunctive use of effective antibiotics. Open drainage is reserved for abscesses for which percutaneous drainage is inappropriate or unsuccessful.
Peritoneal mesothelioma		Arises from the mesothelium lining the peritoneal cavity. Its incidence is approximately 300-500 new cases being diagnosed in the United States each year. As with pleural mesothelioma, there is an association with an asbestos exposure. Most commonly affects men at the age of 50-69 years. Patients most often present with abdominal pain and later increased abdominal girth and ascites along with anorexia, weight loss and abdominal pain. Mean time from diagnosis to death is less than 1 year without treatment.	CT with intravenous contrast typically demonstrates the thickening of the peritoneum. Laparoscopy with tissue biopsy or CT guided tissue biopsy with immunohistochemical staining for calretinin, cytokeratin 5/6, mesothelin, and Wilms tumor 1 antigen remain the gold standard for diagnosis.	At laparotomy the goal is cytoreduction with excision. Debulking surgery and intraperitoneal chemotherapy improves survival in some cases.
peritoneal carcinomatosis		Associated with a history of ovarian or GI tract malignancy. Symptoms include ascites, abdominal pain, nausea, vomiting.

Diagnosis

Radiographs of the abdomen can show air-fluid levels similar to those in patients with any other cause of small-bowel obstruction.
In the appropriate clinical setting, recognition of the entire dilated small bowel at the center of the abdomen and encased within a thick fibrocollageneous membrane, as though it were in a cocoon, on a CT image is diagnostic of sclerosing encapsulating peritonitis.
The other imaging findings may include signs of obstruction, fixation of intestinal loops, ascites or localized fluid collections, bowel wall thickening, peritoneal or mural calcification, and reactive adenopathy.

Diagnostic Findings

Patient #1:

CT and gross pathological images demonstrate sclerosing encapsulating peritonitis. The patient was on long term peritoneal dialysis

Images courtesy of RadsWiki

References

↑ Mustafa Kemal Demir, Okan Akinci, Ender Onur, and Neset Koksal. Case 108: Sclerosing Encapsulating Peritonitis. Radiology 2007 242: 937-939.

External Links

Goldminer: Sclerosing encapsulating peritonitis

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[1] Mustafa Kemal Demir, Okan Akinci, Ender Onur, and Neset Koksal. Case 108: Sclerosing Encapsulating Peritonitis. Radiology 2007 242: 937-939.

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