Imaging pearls and differential diagnosis of encapsulating peritoneal sclerosis: Emphasis on computed tomography

Encapsulating peritoneal sclerosis (EPS) is a severe peritoneal fibrotic reaction most frequently identified as a complication of peritoneal dialysis. EPS is a complex condition whose management requires multidisciplinary input from radiologists, gastroenterologists, nephrologists, surgeons, and dietitians. EPS carries significant morbidity and mortality, primarily due to bowel obstruction that results in intestinal failure, malnutrition, and sepsis. The nondialysis causes of EPS include tuberculous peritonitis, prior abdominal surgery, beta-blocker medication use, and endometriosis. The clinical symptoms of EPS are nausea, vomiting, and abdominal pain, all of which appear to be associated with bowel obstruction. The diagnosis of EPS needs three pillars to be met: clinical features, radiological evaluation, and histopathological analysis. The disease is frequently progressive and can be fatal. Computed tomography is the gold standard imaging modality for the detection of peritoneal abnormalities and encapsulation of bowel loops by thick adhesions or fibrosis (cocooning). Computed tomography also aids in making a differential diagnosis. Unfortunately, the diagnosis of EPS is often delayed because clinical findings are not specific and may resemble other peritoneal diseases. Radiologists should be familiar with the clinical impacts and related imaging features of EPS and realize when to seek them to facilitate timely and proper treatment.

Surgical management of Encapsulating Peritoneal Sclerosis (EPS) in children: international case series and literature review

BACKGROUND

Encapsulating Peritoneal Sclerosis (EPS) is a rare phenomenon in paediatric patients with kidney failure treated with peritoneal dialysis (PD). This study highlights clinical challenges in the management of EPS, with particular emphasis on peri-operative considerations and surgical technique.

METHODS

Retrospective analysis of all paediatric patients with EPS treated at the Manchester Centre for Transplantation.

RESULTS

Four patients were included with a median duration of 78 months on PD. All patients had recurrent peritonitis (> 3 episodes), and all had symptoms within three months of a change of dialysis modality from PD to haemodialysis or transplant. In Manchester, care was delivered by a multi-disciplinary team, including surgeons delivering the adult EPS surgical service with a particular focus on nutritional optimisation, sepsis control, and wound management. The surgery involved laparotomy, lavage, and enterolysis of the small bowel + / - stoma formation, depending on intra-abdominal contamination. Two patients had a formal stoma, which were reversed at three and six months, respectively. Two patients underwent primary closure of the abdomen, whereas two patients had re-look procedures at 48 h with secondary closure. One patient had a post-operative wound infection, which was managed medically. One patient's stoma became detached, leading to an intra-abdominal collection requiring re-laparotomy. The median length of stay was 25 days, and patients were discharged once enteral feeding was established. All patients remained free of recurrence with normal gut function and currently two out of four have functioning transplants.

CONCLUSIONS

This series demonstrates 100% survival and parenteral feed independence following EPS surgery. Post-operative morbidity was common; however, with individualised experience-based decision-making and relevant additional interventions, patients made full recoveries. Health and development post-surgery continued, allowing the potential for transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Idiopathic cocoon abdomen with congenital colon malrotation: a case report and review of the literature

BACKGROUND

Cocoon abdomen is a relatively rare abdominal disease characterized by the total or partial encasement of the small intestinal by a dense fibro-collagenous membrane.

CASE PRESENTATION

We reported an unusual case of idiopathic cocoon abdomen with congenital colon malrotation. Laparotomy and sac release were performed on the patient. The patient was no recurrence 6 months after operation. A literature review was also performed.

CONCLUSION

Preoperative diagnosis of abdominal cocoon is difficult. A careful history, physical examination and appropriate radiology may be helpful in making a definitive diagnosis. If conservative treatment can't relieve symptoms effectively, surgery is currently considered to be important in the management of this disease.

Renal Association Clinical Practice Guideline on peritoneal dialysis in adults and children

These guidelines cover all aspects of the care of patients who are treated with peritoneal dialysis. This includes equipment and resources, preparation for peritoneal dialysis, and adequacy of dialysis (both in terms of removing waste products and fluid), preventing and treating infections. There is also a section on diagnosis and treatment of encapsulating peritoneal sclerosis, a rare but serious complication of peritoneal dialysis where fibrotic (scar) tissue forms around the intestine. The guidelines include recommendations for infants and children, for whom peritoneal dialysis is recommended over haemodialysis.Immediately after the introduction there is a statement of all the recommendations. These recommendations are written in a language that we think should be understandable by many patients, relatives, carers and other interested people. Consequently we have not reworded or restated them in this lay summary. They are graded 1 or 2 depending on the strength of the recommendation by the authors, and A-D depending on the quality of the evidence that the recommendation is based on.

A combination of corticosteroid, sirolimus, and intradialytic parenteral nutrition in encapsulating peritoneal sclerosis: Case report and literature review

Encapsulating peritoneal sclerosis (EPS) is a rare complication of peritoneal dialysis that carries a high morbidity and mortality. Although its pathogenesis is still not clear, the "two hit theory" suggests that long term deterioration of the peritoneum combined with intraperitoneal inflammation is needed in the pathogenesis of EPS. To date, there is no proven effective therapy with an absence of randomized controlled trials. Individual case reports and small case series have reported on the use of tamoxifen and corticosteroids for medical management of EPS. Here, we present the first case of EPS treated successfully with a combination of sirolimus, low dose corticosteroid and intradialytic parenteral nutrition. A critical review of the relevant literature on this subject is also presented to determine the best approach.

mTOR inhibitors for medical treatment of post-transplantation encapsulating peritoneal sclerosis: a favourable single center experience

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is a serious complication in patients on peritoneal dialysis (PD) causing intestinal obstruction. Two different forms of EPS are reported: the classical one observed in patients on PD, and post-transplantation EPS (PostTx-EPS). The first-line therapy of classical and PostTx-EPS remains surgical treatment, but for both the complication rate and mortality are high. Recently, a few cases of EPS were successfully treated with inhibitors of mammalian target of rapamycin (mTORi). The aim of this study was to evaluate PostTx-EPS outcome in our patients, focusing on the potential benefit of mTORi treatment.

METHODS

We performed a retrospective analysis on 1,048 kidney transplanted patients at our center between 11/2001 and 12/2011.

RESULTS

In the 226 patients treated with PD at any time before grafting, we found 10 cases of PostTx-EPS (prevalence 4.4%). The mean age was 54.9 years (26-69), with a mean time on PD of 83.1 months (33-156). The interval between kidney transplant and EPS diagnosis was 10.5 months (4-18.9). Five of the ten patients were treated after the diagnosis with mTORi, with a favorable outcome in 4/5 cases. This result was substantially independent of surgical and steroid therapy, performed in 9/10 and 10/10 patients respectively.

CONCLUSION

EPS is a serious complication but susceptible to improvement if early diagnosed. mTORi represent a useful option for EPS treatment. We too suggest adopting an immunosuppressive protocol based on mTORi, mycophenolate mofetil and steroids in order to prevent PostTx-EPS in transplanted patients at high risk.

Encapsulating peritoneal sclerosis-a rare but devastating peritoneal disease

Encapsulating peritoneal sclerosis (EPS) is a devastating but, fortunately, rare complication of long-term peritoneal dialysis. The disease is associated with extensive thickening and fibrosis of the peritoneum resulting in the formation of a fibrous cocoon encapsulating the bowel leading to intestinal obstruction. The incidence of EPS ranges between 0.7 and 3.3% and increases with duration of peritoneal dialysis therapy. Dialysis fluid is hyperosmotic, hyperglycemic, and acidic causing chronic injury and inflammation in the peritoneum with loss of mesothelium and extensive tissue fibrosis. The pathogenesis of EPS, however, still remains uncertain, although a widely accepted hypothesis is the "two-hit theory," where, the first hit is chronic peritoneal membrane injury from long standing peritoneal dialysis followed by a second hit such as an episode of peritonitis, genetic predisposition and/or acute cessation of peritoneal dialysis, leading to EPS. Recently, EPS has been reported in patients shortly after transplantation suggesting that this procedure may also act as a possible second insult. The process of epithelial-mesenchymal transition of mesothelial cells is proposed to play a central role in the development of peritoneal sclerosis, a common characteristic of patients on dialysis, however, its importance in EPS is less clear. There is no established treatment for EPS although evidence from small case studies suggests that corticosteroids and tamoxifen may be beneficial. Nutritional support is essential and surgical intervention (peritonectomy and enterolysis) is recommended in later stages to relieve bowel obstruction.

Living with encapsulating peritoneal sclerosis (EPS): the patient's perspective

BACKGROUND

Although relatively rare, encapsulating peritoneal sclerosis (EPS) is nonetheless a major concern within the renal community. Risk of developing EPS is associated with long-term peritoneal dialysis (PD). High mortality was previously reported, although surgery has since improved outcomes. Research into EPS focuses on imaging and early detection methods, genetics, biomarkers and preventive strategies. No previous studies have examined patients' experiences of EPS.

AIMS

The aim of the present study was to explore the experience of patients who have undergone surgery for EPS in one center in the North of England.

METHODS

A qualitative phenomenological approach, involving in-depth interviews, was adopted. Nine participants were recruited out of a total of 18 eligible. Most participants were interviewed twice over a 12-month period (October 2009 to October 2010).

ANALYSIS

Interpretive data analysis was conducted, following the philosophical tradition of hermeneutics, to draw out themes from the data. Data collection and analysis took place concurrently and participants were sent a summary of their first interview to allow a period of reflection prior to the subsequent interview.

RESULTS

EPS presented the most serious challenge participants had faced since developing chronic kidney disease (CKD). Three major themes were identified, each with subcategories. The key issues for patients were related to identification of early symptoms and lack of understanding. The patients' sense of 'not being heard' by health care professionals led to a loss of trust and enhanced their feelings of uncertainty. The enormity of the surgery, the suffering, and what they had to endure had an enormous impact, but an overriding aspect of this experience was also the loss they felt for their independence and for the PD therapy over which they had control.

CONCLUSIONS

The findings of this study highlight a number of important issues relevant to clinical practice, including lack of information and understanding of EPS, particularly its early symptoms At the time patients transfer from peritoneal to hemodialysis, the provision of adequate information about the risks and potential early signs of EPS may not only improve their experiences, but may also assist in early detection.

Encapsulating peritoneal sclerosis in children

Encapsulating peritoneal sclerosis (EPS) is a rare but extremely serious complication of peritoneal dialysis (PD). While EPS has been well recognized in adults on long-term PD, and children can spend many years on PD before a transplant becomes available, only a small number of children with EPS have been described. Two European pediatric registries have recently reported on the prevalence, potential risk factors and outcomes of EPS in children. Although the prevalence of EPS is comparable to that published in adult registries, the outcome of pediatric EPS is significantly better and carries a lower mortality. All studies have shown a greater risk of EPS with a longer dialysis vintage, but it is not known why some individuals are susceptible to EPS development. In this review we discuss current views on the epidemiology, pathogenesis and management strategies for EPS. The hope of the authors is that this review will alert pediatric nephrologists to this rare but extremely serious complication of chronic PD. In the future, collaborative research and the establishment of a pediatric EPS registry may be of importance in helping pediatric nephrologists to recognize the early warning signs of EPS development and thereby to develop strategies for its prevention and optimal management.

Anthropometrics Identify Wasting in Patients Undergoing Surgery for Encapsulating Peritoneal Sclerosis

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INTRODUCTION

Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis in which gastrointestinal (GI) symptoms reduce appetite and dietary intake. Adequate nutrition is important, especially if surgery is required. Although the incidence of EPS is low, the present report is able to detail preoperative nutrition status and treatment in a large cohort of patients from a national EPS referral center. ♦

METHODS

Of 51 patients admitted to this EPS specialist center hospital for their first peritonectomy in the study period, 50 had a preoperative dietetic assessment, and 49 underwent upper-arm anthropometry. ♦

RESULTS

Mean body mass index (BMI) was 20.6 kg/m(2). Mean weight loss was 14% of body weight in the preceding 6 months, with 35 of 50 patients losing more than 10%. On anthropometry, 25 of 49 patients were below the 5th percentile for mid-arm circumference (MAC), 17 of 49 were below for triceps skinfold thickness (TSF), and 21 of 49 were below for mid-arm muscle circumference (MAMC). Mean handgrip strength (HGS) was 60% of normal, with 43 of 49 patients being below 85% of normal. Appetite was poor in 21 of 50 patients, and 37 of 50 had upper and 40 of 50 had lower GI symptoms. By subjective global assessment, 27 of 51 patients were graded as severely malnourished, and 5 of 51, as well-nourished. Mean serum albumin was 28 g/L and did not correlate with BMI, MAC, TSF, MAMC, or HGS. In most patients, C-reactive protein was elevated (mean: 111 mg/L). Preoperative parenteral nutrition was given to 46 of 51 patients for a mean of 21 days. ♦

DISCUSSION

Our findings demonstrate the poor nutrition status of patients admitted for EPS surgical intervention. Anthropometrics reveal depleted fat and lean body mass in EPS patients, which might be a result of anorexia and inflammation, and the reason that albumin was not an accurate marker of nutrition. Poor nutrition status is likely to negatively affect outcome in this patient group. ♦

CONCLUSIONS

Early recognition of GI symptoms may herald a diagnosis of EPS. Optimization of preoperative nutrition status with intensive nutrition support is needed.

Combined intestine and kidney transplantation in a patient with encapsulating peritoneal sclerosis: case report

Encapsulating peritoneal sclerosis (EPS) is a rare but devastating complication of peritoneal dialysis characterized by fibrosis and calcification of the intestine that, in severe cases, can progress to intestinal failure and total parenteral nutrition dependency. Medical and surgical interventions carry a poor prognosis in these patients. We describe a case of a 36-year-old female with end-stage kidney disease and severe EPS not amenable to surgical intervention who underwent a combined intestinal and kidney transplantation. At 3 years posttransplantation, the patient has normal intestinal and kidney function. This represents, to our knowledge, the first report of severe EPS and end-stage kidney disease treated with a combined transplant.

Nutrition changes in conservatively treated patients with encapsulating peritoneal sclerosis

BACKGROUND

Encapsulating peritoneal sclerosis (EPS), a rare but serious complication of long-term PD, is characterized by nausea, abdominal pain, weight loss, anorexia, and constipation. It can cause a significant deterioration in a patient's nutrition status. In the present study we examined changes in nutrition status and outcomes for patients with EPS treated conservatively without the use of surgical intervention.

METHODS

Patients diagnosed with EPS at our institution between December 2006 and December 2010 were identified, and data on demographics, nutrition, and symptoms were collected every 2 months for 12 months and then at 18 and 24 months.

RESULTS

Of the 15 patients identified, 12 were malnourished or at risk of malnutrition according to their subjective global assessment score, with 11 of the 15 presenting with more than 10% weight loss in the 6 months before diagnosis. Furthermore, symptom burden was high, with 11 of 15 patients reporting 2 or more gastrointestinal symptoms. Of the 15 patients, 12 required parenteral nutrition for a median of 4.5 months, and 5 died within the first 12 months after diagnosis. In the 10 survivors, albumin and C-reactive protein significantly improved over the 24 months after diagnosis. Improving trends in weight and symptoms were also observed in those patients.

CONCLUSIONS

In some patients with EPS, a conservative approach without surgical intervention, and with regular dietetic input and aggressive nutrition support, can lead to improved nutrition status and symptoms.

Proof-of-principle study to detect metabolic changes in peritoneal dialysis effluent in patients who develop encapsulating peritoneal sclerosis

BACKGROUND

Prolonged peritoneal dialysis (PD) therapy can result in the development of encapsulating peritoneal sclerosis (EPS), characterized by extensive sclerosis of the peritoneum with bowel adhesions often causing obstruction.

METHODS

As a proof-of-principle study, holistic profiling of endogenous metabolites has been applied in a prospective collection of PD effluent collected in multiple UK renal centres over 6 years in order to investigate metabolic differences in PD effluent between PD therapy patients who later developed clinically defined EPS (n = 11) and controls, who were matched for PD vintage, age and gender (n = 11).

RESULTS

'Fit-for-purpose' analytical methods employing gas chromatography-mass spectrometry (MS), direct injection MS and quality control samples were developed and validated. These methods were applied in a proof-of-principle study to define metabolic differences in PD effluent related to subsequent development of EPS. Changes in amino acids, amines and derivatives, short-chain fatty acids and derivatives and sugars were observed prior to EPS developing, and changes in the metabolomic profiles could be detected.

CONCLUSION

There is potential for applying metabolic profiles to identify patients at risk of developing EPS although long-term prospective studies with larger patient cohorts are required.

Encapsulating peritoneal sclerosis: what have we learned?

Encapsulating peritoneal sclerosis (EPS) is a rare complication of peritoneal dialysis (PD), but carries significant morbidity and mortality. We review the clinical features and radiologic and histologic changes found at diagnosis of EPS. Although EPS is strongly associated with the duration of PD, the pathogenesis remains only partly understood. We discuss the mechanisms thought to underlie the abnormally thickened, sclerotic peritoneal membrane seen in long-term PD patients including epithelial to mesenchymal transition and the molecular mediators of fibrosis and angiogenesis. We review how exposure to high-glucose, nonphysiological dialysis fluids, peritonitis, and uremia may be responsible for these changes. Much remains to be learned about optimal management of EPS, both medical and surgical, because the literature lacks controlled studies. Future research challenges include defining the role of surgery, immunosuppression, and antifibrotic agents in the management of EPS. We also need to understand why some patients progress from asymptomatic peritoneal sclerosis to the extreme levels of fibrin deposition and bowel encapsulation seen in EPS. Screening PD patients for potential future EPS remains difficult, and we need strategies for monitoring patients on longer-term PD that enable us to better quantify the risk of EPS for the individual patient.

Encapsulating peritoneal sclerosis: the state of affairs

Encapsulating peritoneal sclerosis (EPS) is a severe complication of long-term peritoneal dialysis (PD) with a 50% mortality rate. EPS is characterized by progressive and excessive fibrotic thickening of the peritoneum, leading to encapsulation of the bowels and intestinal obstruction. At present, EPS cannot be detected with certainty during its early stages; however, a progressive loss of ultrafiltration capacity often precedes its development. Studies that attempted to elucidate the pathogenesis of EPS have shown that the duration of exposure to PD fluids is the most important risk factor for EPS, and that young age and possibly the effects of peritonitis are additional contributory factors. The pathophysiology of EPS is probably best described as a multiple-hit process with a central role for transforming growth factor β. A form of EPS that develops shortly after kidney transplantation has also been recognized as a distinct clinical entity, and may be a common form of EPS in countries with a high transplantation rate. Criteria have been developed to identify EPS by abdominal CT scan at the symptomatic stage, but further clinical research is needed to identify early EPS in asymptomatic patients, to clarify additional risk factors for EPS and to define optimal treatment strategies.

Tamoxifen is associated with lower mortality of encapsulating peritoneal sclerosis: results of the Dutch Multicentre EPS Study

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis (PD) with an increasing incidence. There is no clear consensus on the treatment of EPS, but anecdotal reports indicate improvement in EPS patients treated with tamoxifen. At present, there is no evidence for the effect of tamoxifen treatment in EPS patients. This study investigates the effect of treatment with tamoxifen on survival in EPS patients.

METHODS

This study is a retrospective analysis of survival in EPS patients as part of the Dutch multicentre EPS study in the period January 1996 to July 2007. Sixty-three patients with severe EPS were followed up until August 2008. Demographic, patient and PD-related variables of EPS patients were investigated. Patients treated with tamoxifen were compared to patients not treated with tamoxifen. Survival was analysed with multivariate Cox regression analysis.

RESULTS

Twenty-four patients were treated with tamoxifen, and 39 were not treated with tamoxifen. The clinical and demographic characteristics were similar for the tamoxifen-treated and non-treated groups. The mortality rate was significantly lower in tamoxifen-treated patients compared to EPS patients not treated with tamoxifen (45.8% vs 74.4%, P=0.03). Survival in tamoxifen-treated patients, adjusted for calendar time, age, use of corticosteroids, presence of functioning transplantation, use of parental nutrition and centre influences was longer in comparison to not-treated patients (HR 0.39, P=0.056).

CONCLUSIONS

Tamoxifen treatment in EPS patients is associated with lower mortality and shows a trend to an increased multivariate-adjusted survival. This supports additional use of tamoxifen to treat patients with severe EPS.

Long-term peritoneal dialysis and encapsulating peritoneal sclerosis in children

Encapsulating peritoneal sclerosis (EPS) is the most serious complication of long-term peritoneal dialysis (PD), with a mortality rate that exceeds 30%. There have been many reports of the incidence of EPS being strongly correlated to the duration of PD. Patients on PD for longer than 5 years, and especially those receiving this treatment for more than 8 years, should undergo careful and repeated surveillance for risk factors associated with the development of EPS. The development of ultrafiltration failure, a high dialysate/plasma creatinine ratio, as determined by the peritoneal equilibration test, peritoneal calcification, a persistently elevated C-reactive protein level, and severe peritonitis in patients on PD for longer than 8 years are signals that should prompt the clinician to consider terminating PD as a possible means of preventing the development of EPS. The impact of the newer, biocompatible PD solutions on the incidence of EPS has not yet been determined.

How Can Genetic Advances Impact on Experimental Models of Encapsulating Peritoneal Sclerosis?

In this review we discuss how animal models have contributed to the understanding of pathological pathways that may be involved in the development of encapsulating peritoneal sclerosis. We review the various interventional procedures that, so far, have ameliorated disease progression in animals. Reviewing advancements in molecular biology and genetic technologies, we discuss how future experimental models may impact our understanding of the pathogenesis and treatment of this rare but complex disease.