Localized Encapsulating Peritoneal Sclerosis Constricting the Terminal Ileum—An Unusual Appearance Requiring Surgical Intervention

Abstract

♦ Background: Encapsulating peritoneal sclerosis (EPS) is a rare complication of peritoneal dialysis (PD). It is characterized by encapsulation of the bowel, causing symptoms of intestinal obstruction. Exclusive involvement of parts of the bowel may occur and may be more common than previously thought. Our main objective was to investigate and report on patients with localized EPS.

♦ Methods: Between July 2002 and December 2011, 9 of 17 EPS patients were referred to our department of surgery for a diagnostic laparotomy. Three of the 9 cases showed localized encapsulation of the small bowel and were selected for the purpose of this study.

♦ Results: All 3 patients presented with an acute inflammatory state and symptoms of bowel obstruction. In 2 patients, EPS became clinically overt after kidney transplantation; the third patient was diagnosed while on hemodialysis. All shared a history of PD ranging from 31 to 101 months. In none of the patients was radiologic examination conclusive, although 2 showed peritoneal thickening and ascites. Each patient underwent laparotomy, confirming EPS. In all cases, a thickened peritoneal membrane became apparent, predominantly covering the ileocecal region of the intestine. In addition, a constrictive membrane at the level of the terminal ileum was noted. In 2 cases, the patients underwent enterolysis and dissection of the constricting fibrotic peritoneal membrane (peritonectomy) without bowel resection. The 3rd patient was managed with parenteral nutrition and tamoxifen. The postoperative course in 1 patient was complicated by infected ascites that resolved with antibiotic treatment. Eventually, all patients were doing well, with adequate oral intake and without the need for repeat surgery.

♦ Conclusions: Localized EPS may be more common than previously thought. It has a predilection for the level of the terminal ileum. We believe that an elective diagnostic laparotomy should be considered early, because this procedure offers both diagnostic opportunities and therapeutic options. Localized EPS cases may benefit most from enterolysis and peritonectomy.

Encapsulating peritoneal sclerosis (EPS), a rare complication of peritoneal dialysis (PD), can become manifest in the course of PD treatment or in former PD patients after transfer to hemodialysis (HD) or receipt of a kidney graft. The single most important risk factor for EPS is cumulative time on PD (1). It is postulated that the disease is the consequence of an inflammatory healing response of a peritoneum that has been exposed to bioincompatible dialysis fluids. The result is excessive thickening of the peritoneal membrane surrounding the bowel, which may eventually cause symptoms of intestinal obstruction.

A diagnosis of EPS can be made when symptoms of obstructed bowel passage are present in combination with characteristic computed tomography (CT) findings (2). In some cases, though, a definite diagnosis of EPS requires surgical exploration. The classical macroscopic appearance of EPS is total encapsulation of the bowel by a fibrotic membrane (3). However, exclusive involvement of parts of the bowel may occur and could be more common than previously reported. Our main objective was to investigate and report on patients with localized EPS.

Methods

Between July 2002 and December 2011, 17 cases of EPS were diagnosed at our center. Of the affected patients, 9 were referred to the department of surgery for diagnostic laparotomy. Patient histories were analyzed in reference to renal replacement therapy, clinical picture, radiologic findings, surgical findings, and treatment. When surgical exploration showed localized encapsulation in the abdominal cavity, the presentation was defined as localized EPS, and the patient was selected for the purpose of this study. The study was approved by the institutional board of the medical ethics committee of Erasmus Medical Center.

Results

In this group of 9 patients referred for diagnostic laparotomy, 3 were classified as having localized EPS. The case histories of those patients are described next.

Case 1

A 28-year-old man was admitted to our hospital 1 week after removal of his PD catheter because of ileus and elevated serum C-reactive protein [CRP (152 mg/L)]. Nine months earlier, he had undergone an uncomplicated second kidney transplantation (KTx), with serum creatinine of 131 μmol/L. Plain radiography showed multiple dilated small bowel loops with fluid levels. Imaging of the abdomen by CT revealed mesenteric infiltration that was focused mainly in the right lower quadrant, ascites, and a marginally thickened peritoneum. Those findings were not considered diagnostic for EPS.

The patient’s medical history included end-stage renal disease secondary to tubulointerstitial nephropathy. He had a 15-month history of PD before his first KTx and 86 months before his second Ktx. The clinical course during his second PD period was complicated by 3 episodes of peritonitis. His immunosuppressive regimen included prednisone, tacrolimus, and mycophenolate mofetil. He had experienced intermittent attacks of abdominal pain 3 weeks before admission.

The patient’s condition did not improve with a conservative approach (intravenous fluids, bowel rest, and nasogastric suction), and a diagnostic laparotomy was performed. Inspection of the small bowel identified proximal dilatation. Specifically, about 20 cm of the terminal ileum was covered by thickened and fibrotic peritoneal membrane, with an additional overlying adhesion band. The constricting adhesion band was cleaved, thereby releasing the contained part of the bowel and restoring normal peristaltic movement. Parenteral nutrition was instituted for 10 days, and the patient was discharged 21 days postoperatively in good clinical condition.

Symptoms of obstructive bowel passage recurred at 5, 11, and 21 months after the initial diagnosis. During all episodes, strict dietary regulation using a liquid diet or total parenteral nutrition resulted in quick resolution of symptoms. The patient was started on 10 mg tamoxifen twice daily, which may have contributed to the prevention of further recurrences. After 8 years of follow-up, the patient is doing well, with adequate oral intake.

Case 2

A 37-year-old man was admitted to our hospital because of a fourth episode of recurrent ileus. The patient’s medical history revealed end-stage renal disease secondary to focal segmental glomerulosclerosis. He was successfully transplanted after being treated with PD for 26 months without any infectious complications. Immunosuppressive therapy consisted of prednisone, tacrolimus, and mycophenolate mofetil. At 2.5 years after KTx, this patient experienced progressive loss of graft function because of recurrent focal segmental glomerulosclerosis, necessitating re-initiation of PD treatment. A transplantectomy was performed 5 months later, incurring peritoneal damage that necessitated HD treatment thereafter.

At 2.5 months after the switch to HD, the patient presented with symptoms of bowel obstruction. This complaint initially responded to conservative management, but eventually persisted. The patient’s serum CRP was elevated, reaching a maximum of 238 mg/L. Imaging of the abdomen by CT showed dilated small bowel loops, but no classical signs of EPS (Figure 1).

Figure 1 —

Computed tomography imaging of the abdomen in case 2 showed dilated small-bowel loops (arrowhead) and ascites (star), but no classical signs of encapsulating peritoneal sclerosis.

The history of this patient’s recurrent obstructive symptoms and multiple admissions led to an exploratory laparotomy, during which a white and slightly thickened peritoneum was observed covering the small intestine (Figure 2), liver, and spleen. In particular, an obvious sclerotic layer was noted, encasing a loop of the terminal ileum. Enterolysis and stripping of the sclerotic layer were performed, releasing the encased bowel loop, which regained motility. The postoperative course was uneventful, and total parenteral nutrition was instituted until bowel movements returned.

Figure 2 —

Localized appearance of encapsulating peritoneal sclerosis at laparotomy.

The patient was discharged after 17 days, thereafter started a normal diet, and continued on tamoxifen therapy (20 mg once daily).

Case 3

A 52-year-old male renal graft recipient was admitted to our hospital with a 2.5-month history of diarrhea, subacute abdominal pain, nausea, and vomiting. This patient had a history of diabetic end-stage renal disease, for which he was treated with PD for 32 months without experiencing any peritonitis episodes. He had undergone a living-donor KTx 6 months before the current admission and had received a triple immunosuppressive regimen of prednisone, tacrolimus, and mycophenolate mofetil.

Abdominal examination revealed ascites, right upper quadrant tenderness, and right lower quadrant pain on palpation. Laboratory tests showed signs of systemic inflammation (CRP 40 mg/L) and a serum creatinine of 129 μmol/L. Ascitic fluid examination was negative on bacterial culture.

Abdominal radiography showed dilated loops of jejunum with small-bowel air-fluid levels. Abdominal CT imaging showed massive ascites, small-bowel ileus, and a slightly thickened peritoneal membrane.

In a planned diagnostic laparotomy, thickened peritoneum covered by a whitish membrane was found to be encasing the part of the jejunum proximal to the ileocecal area. In particular, constrictive stenosis of the terminal ileum because of the thickened peritoneum was noted.

The patient’s postoperative period was complicated by infected ascites, successfully treated with antibiotics. Conservative treatment was continued, with the addition of total parenteral nutrition. The patient’s serum CRP returned to normal in 5 weeks, and the patient was discharged from hospital with restored bowel passage and adequate oral intake.

Because of recurrent symptoms of bowel obstruction, this patient was given tamoxifen therapy (20 mg twice daily). Thereafter, the number and severity of recurrent episodes of bowel obstruction markedly decreased, and he died of untreatable ischemic cardiac disease 8 years after the initial diagnosis of EPS.

Discussion

In the cases presented, an intraoperative diagnosis of localized EPS was made in 3 patients who presented with an acute inflammatory state and symptoms of bowel obstruction. In 2 patients, EPS became clinically overt after KTx; the third patient was diagnosed while on HD. They all shared a history of PD, with cumulative exposures of 101, 31, and 32 months respectively. In none of the patients was radiologic examination conclusive, and the final diagnosis of EPS was made during laparotomy. In all 3 cases, an obviously sclerotic and thickened peritoneal membrane was observed, predominantly covering and constricting the terminal ileum.

The number of localized EPS cases in our series is relatively small, but the condition is clearly not a rare finding and should be considered when a patient suspected for EPS shows few abnormalities on CT imaging. Classically, the macroscopic feature of EPS is a cocooning condition that involves nearly all parts of the small bowel (3).

The specific findings in our cases may add interesting clues to the understanding of this rare disease. First, the appearance was unusual in that the ileocecal region was particularly involved. Only one other study has considered this localized pathology of EPS, reporting surgical exploration in a transplanted patient with a 5-year history of PD (4). Second, the findings in our cases also demonstrate that it may be extremely difficult to establish a diagnosis of EPS preoperatively, especially when the process of fibrosis has not extended to the entire peritoneal surface of the abdominal cavity. Imaging of the abdomen by CT in cases 1 and 3 alerted us to a slightly thickened peritoneum and the presence of ascites. However, the exact nature of the lesion was not revealed. Tarzi et al. validated CT scoring parameters— including peritoneal calcification, bowel tethering, bowel wall thickening, dilated bowel loops, peritoneal thickening, and ascites—to assist in the diagnosis of EPS (5). However, the same authors also suggested that CT imaging may not be conclusive in the early detection of EPS. The localized pathology in our patients adds another level of complexity, because it appears to be difficult to identify the condition by CT imaging. Our patients therefore highlight the need to consider a diagnostic laparotomy early as a definitive diagnostic tool.

Immunosuppressive drugs and tamoxifen are reported to be of value in the management of EPS, especially in the inflammatory stage (6). Tamoxifen is an antagonist of the estrogen receptor, and previous work suggests that its antifibrotic mechanisms of action could be a result of inhibition of transforming growth factor β production (7). This agent has also been used in the management of other fibrosing disorders, such as retroperitoneal fibrosis (8). Eltoum et al. (9) previously reported resolution of peritoneal thickening 6 months after tamoxifen therapy in 1 patient. In addition, Korte et al. (10) reported mortality rates that were lower in EPS patients who were treated with tamoxifen than in those who were not. Unfortunately, the optimal treatment regime or the optimal dose of tamoxifen for EPS has not been established because no randomized controlled trials have yet been performed.

Surgical enterolysis is the recommended treatment when features of intestinal obstruction occur. In an observational retrospective study, Kawanishi et al. (11) outlined their experience with EPS surgery in 181 patients. Those authors presented favorable surgical outcomes with a postsurgical mortality of 7.7% and overall mortality of 35.4%. In agreement with them and with other authors, we believe that early surgical treatment should be undertaken in cases that present with severe and recurrent symptoms of intestinal obstruction, not resolving with conservative treatment. In 2 of our 3 cases, release of the constricting fibrous membrane and enterolysis were all that was required to free the bowel. In case 3, no surgery for the purpose of EPS relief was performed, although there seemed to be a clear indication for it during the laparotomy. The decision not to pursue surgery was taken because EPS surgery was considered to be a high-risk procedure, indicated only in selected cases of irreversible and complicated bowel obstruction.

Conclusions

Our cases highlight an unusual appearance of EPS. Localized EPS may be more common than previously thought and has a predilection to appear at the level of the terminal ileum. We believe that an elective diagnostic laparotomy, preferably performed by a surgeon familiar with EPS surgery, should be considered early, because that approach offers both diagnostic opportunities and therapeutic options. Localized EPS cases may benefit most from enterolysis and a peritonectomy.

Disclosures

The authors have no conflicts of interest to disclose.