EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Encapsulating peritoneal sclerosis is a rare but highly morbid disease process in patients with end-stage kidney disease on peritoneal dialysis. Surgical management has been described in patients with encapsulation of bowel causing obstruction. Here, we describe a case of surgical management in a patient following kidney transplant with medically refractory ascites and lower extremity edema.

Key words : Ascites, Dialysis, Renal transplantation

History
The patient, a 63-year-old man, had received a deceased donor kidney transplant for end-stage kidney disease due to diabetic nephropathy. He presented approximately 4 months posttransplant with refractory ascites and lower extremity edema. Before the kidney transplant, he had been on peritoneal dialysis for 3 years and had episodes of peritonitis before transplant. He was initially hospitalized at another facility for 2 weeks and underwent 4 paracenteses for refractory ascites. Kidney function remained at his baseline level during this time, with creatinine ranging from 0.80 to 1.25 mg/dL and estimated glomerular filtration rate of >60 mL/min/1.73 m². Ascites was exudative, with cell count of 2731/μL, absolute neutrophil count of 2349/μL, and cultures positive for Pseudomonas. Cytology was negative for malignancy. Liver ultrasonograph scans and portal pressures were normal, and a transjugular liver biopsy did not demonstrate any cirrhosis. The patient was treated with multiple courses of antibiotics for spontaneous bacterial peritonitis, with recurrent accumulation of fluid occurring within 24 hours of drainage. However, despite treatment with multiple antibiotics, his ascites did not improve, and he was refractory to 3 more paracenteses. As a result of ascites, he had poor oral intake and required enteral feeding through a Dobhoff tube.

Management
The patient’s computed tomograph (CT) scan of abdomen/pelvis showed a large, loculated fluid collection in the anterior abdomen with peritoneal thickening measuring approximately 25.9 × 5.2 × 24.9 cm (Figure 1). The patient’s clinical picture was consistent with encapsulating peritoneal sclerosis (EPS). He was started on tamoxifen (10 mg at 3 times daily) and prednisone (10 mg daily). Immunosup-pression was modified from tacrolimus (2 mg daily) to sirolimus (1 mg daily). Given the lack of clinical improvement despite antibiotic therapy and multiple drainage procedures, the decision was made to pursue surgical management with exploratory laparotomy and peritonectomy.

Intraoperatively, on entry, approximately 2 liters of ascites were drained, which was sent for cytology and cultures. Thorough abdominal washout was performed. Loculations were broken down using blunt dissection. Parietal peritoneal flaps were raised (Figure 2). The flaps were raised to the lateral extent of the loculated fluid collection. An approximately 20 × 20-cm piece of parietal peritoneum was excised.

Postoperatively, the patient tolerated the procedure well, with improvement of his appetite. Pathology of the peritoneum was notable for fragments of fibro-adipose tissue with diffuse fibrin deposition, denuded mesothelial lining, extensive acute inflammation, granulation tissue formation, and fibrosis, consistent with the clinical impression of EPS. The patient was subsequently discharged on postoperative day 7, with toleration of diet and with an extended course of antibiotics. Sirolimus (1 mg daily) was held for 3 weeks postoperatively and then resumed.

Follow-up
A multidisciplinary transplant team in clinic provided patient follow-up. The patient showed healed surgical wound, improved nutrition, and complete resolution of his lower extremity edema and ascites. He had lost approximately 12 kg from his baseline weight during his episode of EPS, which he has since regained. The patient resumed sirolimus (1 mg daily) for immunosuppression and remains on tamoxifen (1 mg at 3 times daily) and prednisone (10 mg daily).

Encapsulating peritoneal sclerosis is a rare but highly morbid complication seen in patients who are undergoing peritoneal dialysis. The incidence ranges from approximately 0.5% to 7.3%.^1-3 Mortality ranges from 25% to 55% within the first 12 months of diagnosis.^1-3 Known risk factors include younger age at onset of initiation of peritoneal dialysis, higher dialysate-to-peritoneal creatinine ratios, longer duration of peritoneal dialysis, longer peritonitis duration, presence of glomerulonephritis, and kidney transplantation.⁴ The pathophysiology is thought to be due to a “2-hit” phenomenon. The first hit is from injury to peritoneum at initiation of peritoneal dialysis. The second hit is from an exposure, such as infection, peritonitis, or cessation of peritoneal dialysis, that develops into EPS.⁴ Clinical presentation is nonspecific, and patients may present with anorexia, nausea, diarrhea, and abdominal pain. Cases of EPS may sometimes lead to bowel obstruction, as encapsulation will occur around the bowel either focally or diffusely.⁵ Diagnosis is made with a combination of clinical history and presentation, and CT abdomen will show loculated fluid collections and a thickened peritoneal and abdominal wall.^4,6 Management includes sup-portive care with enteral or parenteral nutrition.⁷ Pharmacological management of EPS includes tamoxifen and glucocorticoids, which both work along different pathways to theoretically reduce the burden of inflammatory and fibrotic responses.^8,9 Tamoxifen has been shown to decrease mortality from 74% to 46%,10 and treatment with glucocorticoids alone has been shown to result in recovery of 38.5% of patients.¹¹

Surgical management has been reserved for cases of EPS with encapsulation of bowel causing bowel obstruction.^12,13 In these cases, the goals of the operation are to perform adhesiolysis to remove the burden of encapsulation and to excise the peritoneum that is a source of fibrosis to minimize the risk of recurrence of encapsulation. Key principles include performing sharp, meticulous, and slow adhesiolysis. Morbidity is high because of the difficulty of dissection and adhesiolysis, as there is an increased risk of iatrogenic enterotomy during adhesiolysis. Despite meticulous adhesiolysis at the index operation, recurrence may occur in up to 20% of patients within 2 years of surgery.^13,14 In the case presented, the indication for surgical management was infected, refractory ascites and lack of response to antibiotic therapy, rather than bowel obstruction. Although cases of refractory ascites as a result of EPS have been described, they have been successfully managed with medical therapy directed toward the underlying infectious or autoimmune cause.¹⁵ However, in our case, the patient demonstrated no resolution of the underlying infectious process despite multiple courses of antibiotics. In addition, due to the patient’s immunosuppressed state following kidney transplant, there was a lower threshold to pursue surgical management for early-stage EPS because of concerns for a persistent infectious burden. Our case suggests that select patients with immunosuppressed states may benefit from earlier surgical intervention for EPS before progression of EPS to the point of bowel obstruction.

Encapsulating peritoneal sclerosis is a rare but highly morbid disease process in patients with end-stage kidney disease on peritoneal dialysis. Along with medical management to decrease inflammatory burden, surgical management should be considered in stages of EPS before progression to bowel obstruction, especially in immunosuppressed patients following a transplant and in patients with persistent infectious burden.

Volume: 22 Issue: 3 March 2024

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