Assessing the validity of an abdominal CT scoring system in the diagnosis of encapsulating peritoneal sclerosis

Complications of Peritoneal Dialysis Part II: Nonmechanical Complications

Peritoneal dialysis (PD) is a form of KRT that offers flexibility and autonomy to patients with ESKD. It is associated with lower costs compared with hemodialysis in many countries. Unlike mechanical complications that typical arise early in the course of treatment, noninfectious, nonmechanical complications often present late in patients who are established on PD. In this review, we first discuss abnormal-appearing drained dialysate, including hemoperitoneum, chyloperitoneum, and noninfectious cloudy dialysate. The underlying cause is frequently unrelated to PD. We then discuss encapsulating peritoneal sclerosis, a rare complication of PD. Finally, we review metabolic changes associated with PD and methods to mitigate its effects.

Renal hyperparathyroidism- a risk factor in the development of encapsulating peritoneal sclerosis

Background

Encapsulating peritoneal sclerosis (EPS) is a rare complication of prolonged peritoneal dialysis (PD) exposure, characterised by peritoneal thickening, calcification, and fibrosis ultimately presenting with life-threatening bowel obstruction. The presence or role of peritoneal calcification in the pathogenesis of EPS is poorly characterised. We hypothesise that significantly aberrant bone mineral metabolism in patients on PD can cause peritoneal calcification which may trigger the development of EPS. We compared the temporal evolution of bone mineral markers during PD in EPS patients with non-EPS long-term PD controls.

Methods

Linear mixed model and logistic regression analysis were used to compare four-monthly serum levels of calcium, phosphate, parathyroid hormone, and alkaline phosphatase (ALP) over the duration of PD exposure in 46 EPS and 46 controls (PD, non-EPS) patients.

Results

EPS patients had higher mean calcium (2.51 vs. 2.41 mmol/L) and ALP (248.00 vs. 111.13 IU/L) levels compared with controls (p=0.01 and p<0.001 respectively, maximum likelihood estimation). Logistic regression analysis demonstrated that high serum calcium and phosphate levels during PD were associated with a 4.5 and 2.9 fold increase in the risk of developing EPS respectively.

Conclusion

High levels of calcium and phosphate in patients on PD were identified to be risk factors for EPS development. Possible reasons for this may be an imbalance of pro-calcifying factors and calcification inhibitors promoting peritoneal calcification which increases peritoneal stiffness. Mechanical alterations may trigger, unregulated fibrosis and subsequent development of EPS. Improved management of secondary hyperparathyroidism during PD may ultimately diminish the EPS risk.

Prediction of surgical outcomes in severe encapsulating peritoneal sclerosis using a computed tomography scoring system

BACKGROUND/PURPOSE

Encapsulating peritoneal sclerosis (EPS) is a rare and potential lethal complication of peritoneal dialysis characterized by bowel obstruction. Surgical enterolysis is the only curative therapy. Currently, there are no tools for predicting postsurgical prognosis. This study aimed to identify a computed tomography (CT) scoring system that could predict mortality after surgery in patients with severe EPS.

METHODS

This retrospective study enrolled patients with severe EPS who underwent surgical enterolysis in a tertiary referral medical center. The association of CT score with surgical outcomes including mortality, blood loss, and bowel perforation was analyzed.

RESULTS

Thirty-four patients who underwent 37 procedures were recruited and divided into a survivor and non-survivor group. The survivor group had higher body mass indices (BMIs, 18.1 vs. 16.7 kg/m2, p = 0.035) and lower CT scores (11 vs. 17, p < 0.001) than the non-survivor group. The receiver operating characteristic curve revealed that a CT score of ≥15 could be considered a cutoff point to predict surgical mortality, with an area under the curve of 0.93, sensitivity of 88.9%, and specificity of 82.1%. Compared with the group with CT scores of <15, the group with CT scores of ≥15 had a lower BMI (19.7 vs. 16.2 kg/m2, p = 0.004), higher mortality (4.2% vs. 61.5%, p < 0.001), greater blood loss (50 vs. 400 mL, p = 0.007), and higher incidence of bowel perforation (12.5% vs. 61.5%, p = 0.006).

CONCLUSION

The CT scoring system could be useful in predicting surgical risk in patients with severe EPS receiving enterolysis.

Magnesium inhibits peritoneal calcification as a late-stage characteristic of encapsulating peritoneal sclerosis

Peritoneal calcification is a prominent feature of the later stage of encapsulating peritoneal sclerosis (EPS) in patients undergoing long-term peritoneal dialysis (PD). However, the pathogenesis and preventive strategy for peritoneal calcification remain unclear. Peritoneum samples from EPS patients were examined histologically. Peritoneal calcification was induced in mice by feeding with an adenine-containing diet combined with intraperitoneal administration of lipopolysaccharide and a calcifying solution containing high calcium and phosphate. Excised mouse peritoneum, human mesothelial cells (MeT5A), and mouse embryonic fibroblasts (MEFs) were cultured in calcifying medium. Immunohistochemistry confirmed the appearance of osteoblastic differentiation-marker-positive cells in the visceral peritoneum from EPS patients. Intraperitoneal administration of magnesium suppressed peritoneal fibrosis and calcification in mice. Calcifying medium increased the calcification of cultured mouse peritoneum, which was prevented by magnesium. Calcification of the extracellular matrix was accelerated in Met5A cells and MEFs treated with calcification medium. Calcifying medium also upregulated osteoblastic differentiation markers in MeT5A cells and induced apoptosis in MEFs. Conversely, magnesium supplementation mitigated extracellular matrix calcification and phenotypic transdifferentiation and apoptosis caused by calcifying conditions in cultured MeT5A cells and MEFs. Phosphate loading contributes to the progression of EPS through peritoneal calcification and fibrosis, which can be prevented by magnesium supplementation.

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.

Encapsulating peritoneal sclerosis: Your questions answered

Encapsulating peritoneal sclerosis (EPS) is a clinical syndrome hallmarked by the formation of a fibrous cocoon encapsulating the bowel resulting in morbidity and mortality. EPS is most frequently associated with peritoneal dialysis (PD), particularly with its discontinuation. While EPS is one of the most feared complications of PD, the majority of patients receiving PD will not go on to develop EPS. Risk factors for development include time on PD, some types of peritonitis and discontinuation of PD. Owing to its rarity, much of the knowledge of EPS comes from case series and registries and treatments are extrapolated from low-quality evidence. Malnutrition is a significant driver of mortality, and nutritional support is critical in management. We present a case of EPS and frequently asked questions including the definition, diagnosis, epidemiology, pathophysiology, risk factors, role of infection, management and roles of nutrition and surgery.

Peritoneal effluent MicroRNA profile for detection of encapsulating peritoneal sclerosis

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is a catastrophic complication of peritoneal dialysis (PD) with high mortality. Our aim is to develop a novel noninvasive microRNA (miRNA) test for EPS.

METHODS

We collected 142 PD effluents (EPS: 62 and non-EPS:80). MiRNA profiles of PD effluents were examined by a high-throughput real-time polymerase chain reaction (PCR) array to first screen. Candidate miRNAs were verified by single real-time PCR. The model for EPS prediction was evaluated by multiple logistic regression and machine learning.

RESULTS

Seven candidate miRNAs were identified from the screening of PCR-array of 377 miRNAs. The top five area under the curve (AUC) values with 5 miRNA-ratios were selected using 127 samples (EPS: 56 vs non-EPS: 71) to produce a receiver operating characteristic curve. After considering clinical characteristics and 5 miRNA-ratios, the accuracies of the machine learning model of Random Forest and multiple logistic regression were boosted to AUC 0.97 and 0.99, respectively. Furthermore, the pathway analysis of miRNA associated targeting genes and miRNA-compound interaction network revealed that these five miRNAs played the roles in TGF-β signaling pathway.

CONCLUSION

The model-based miRNA expressions in PD effluents may help determine the probability of EPS and provide further therapeutic opinion for EPS.

Mesenteric elasticity assessed by shear wave elastography and its relationship with peritoneal function in peritoneal dialysis patients

Background

We evaluated the mesenteric elasticity in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) using shear wave elastography (SWE) and investigated its relationships with peritoneal function.

Methods

Patients were recruited in our peritoneal dialysis (PD) centre between 15 July 2019 and 31 December 2021 and followed up to 31 March 2022. Twelve chronic kidney disease (CKD) patients and nineteen healthy people were included as controls. Correlation, linear regression and Cox regression analyses were applied.

Results

Of the 218 PD patients, 104 (47.8%) were male. Their mean age was 48.0 ± 13.2 years and the median PD duration was 59.0 months [interquartile range (IQR) 17.0-105]. The median mesenteric SWE value was 8.15 kPa (IQR 5.20-16.1). The mesenteric SWE values of patients with a PD duration of <3 months [5.20 kPa (IQR 3.10-7.60)] were not significantly different from those of CKD patients [4.35 kPa (IQR 2.63-5.20), P = .17] and healthy controls [3.60 kPa (IQR 2.90-5.10), P = .13] but were lower than those of patients with a PD duration of 3 months-5 years [6.40 kPa (IQR 4.10-10.5), P < .001], 5-10 years [11.9 kPa (IQR 7.40-18.2), P < .001] and >10 years [19.3 kPa (IQR 11.7-27.3), P < .001]. Longer PD duration (β = 0.58, P < .001), high effluent interleukin-6 (β = 0.61, P = .001) and low effluent cancer antigen 125 (β = -0.34, P = .03) were independently associated with low mesenteric elasticity. The mesenteric SWE value was independently correlated with the dialysate:plasma creatinine ratio (β = 0.39, P = .01) and negatively correlated with the total daily fluid volume removed (β = -0.17, P = .03). High mesenteric SWE values were an independent risk factor for death-censored technique failure [adjusted hazard ratio 4.14 (95% confidence interval 1.25-13.7), P = .02).

Conclusions

SWE could be used to non-invasively characterize peritoneal textural changes, which were closely associated with changes in peritoneal function.

Concurrent development of encapsulating peritoneal sclerosis and calciphylaxis in a patient with peritoneal dialysis for end-stage renal disease

Both encapsulating peritoneal sclerosis (EPS) and calciphylaxis are rare but severe complications involving patients with end-stage renal disease. In this report, we discuss a unique case of a 73-year-old female patient who had undergone 8 years of peritoneal dialysis for IgA nephropathy and concurrently developed these two synchronous complications within 3 months of each other. Diagnosis and management of both conditions were discussed in detail as well as the possible association between the two. With surgical treatment for EPS and measures to minimise bone mineral disorder abnormalities, both complications have been successfully managed to date.

The Peritoneal Membrane—A Potential Mediator of Fibrosis and Inflammation among Heart Failure Patients on Peritoneal Dialysis

Peritoneal dialysis is a feasible, cost-effective, home-based treatment of renal replacement therapy, based on the dialytic properties of the peritoneal membrane. As compared with hemodialysis, peritoneal dialysis is cheaper, survival rate is similar, residual kidney function is better preserved, fluid and solutes are removed more gradually and continuously leading to minimal impact on hemodynamics, and risks related to a vascular access are avoided. Those features of peritoneal dialysis are useful to treat refractory congestive heart failure patients with fluid overload. It was shown that in such patients, peritoneal dialysis improves functional status and quality of life, reduces hospitalization rate, and may decrease mortality rate. High levels of serum proinflammatory cytokines and fibrosis markers, among other factors, play an important part in congestive heart failure pathogenesis and progression. We demonstrated that those levels decreased following peritoneal dialysis treatment in refractory congestive heart failure patients. The exact mechanism of beneficial effect of peritoneal dialysis in refractory congestive heart failure is currently unknown. Maintenance of fluid balance, leading to resetting of neurohumoral activation towards a more physiological condition, reduced remodeling due to the decrease in mechanical pressure on the heart, decreased inflammatory cytokine levels and oxidative stress, and a potential impact on uremic toxins could play a role in this regard. In this paper, we describe the unique characteristics of the peritoneal membrane, principals of peritoneal dialysis and its role in heart failure patients.

Encapsulating peritoneal sclerosis: from early diagnosis to successful kidney transplantation

Encapsulating peritoneal sclerosis is an uncommon but serious complication of peritoneal dialysis. In most cases, the symptoms appear after peritoneal dialysis withdrawal, which hampers its diagnosis. We present the case of a 44-years-old Caucasian male who had been on peritoneal dialysis for 6 years and 3 months and was switched to hemodialysis due to ultrafiltration failure. During his last months on peritoneal dialysis, he developed anorexia and asthenia, which were initially attributed to dialysis inadequacy. After hemodialysis induction, the patient developed abdominal pain, increased abdominal volume, obstipation alternating with diarrhea, and weight loss. Computed tomography showed de novo ascites. A diagnosis of early encapsulating peritoneal sclerosis was considered, and treatment was promptly initiated with nutritional support, oral prednisolone, and tamoxifen for one year. The patient progressed with resolution of the symptoms. One month after the end of the treatment, he underwent a successful kidney transplant and remain without any major intercurrences. A high level of clinical suspicion is crucial for the early diagnosis of encapsulating peritoneal sclerosis as the disease can be fatal in advanced stages. This case highlights that with early treatment, kidney transplantation can be successfully performed after an episode of encapsulating peritoneal sclerosis.

Adverse factors on nonenhanced abdominal CT for long-term continuous ambulatory peritoneal dialysis: a comparative study between patients who withdraw from and maintain long-term peritoneal dialysis

Purpose

To investigate the imaging features of patients with long-term continuous ambulatory peritoneal dialysis (CAPD) on nonenhanced abdominal CT and to identify adverse factors for long-term CAPD.

Methods

A total of 109 patients with less than 5 years of CAPD for peritoneal ultrafiltration failure who switched to hemodialysis (withdrawal group) and 23 patients with more than 10 years of CAPD (long-term group) were retrospectively enrolled. Nonenhanced CT manifestations in both groups were compared, including thickening and calcification of the parietal peritoneum, calcification of the mesangial margin and free margin of the small intestine wall, and calcification of the mesentery and abdominal aorta. A risk stratification model was proposed based on CT manifestations with statistically significant differences.

Results

The presence of the following CT findings was significantly different between two groups: extensive thickening of the parietal peritoneum (78.9% vs. 21.7%, P < 0.01); severe calcification of the parietal peritoneum (60.6% vs. 8.7%, P < 0.01); calcification of the mesentery (32.1% vs. 4.3%, P < 0.05); and calcification of the free margin of the small intestine wall (49.5% vs. 13.0%, P < 0.05). However, there was no significant difference in calcification of the mesangial margin of the small intestine wall (40.3% vs. 30.4%) or in abdominal aortic calcification (56.9% vs. 61.1%) (P > 0.05). The area under the receiver operating characteristic curve (AUC) was 0.906 (sensitivity 87.6% and specificity 82.6%).

Conclusion

Extensive thickening of the parietal peritoneum, severe calcification of the parietal peritoneum, and calcification of the mesentery and the free margin of the small intestine wall are adverse factors for long-term CAPD.

Encapsulating Peritoneal Sclerosis after kidney Transplantation: Success of Medical Treatment

Encapsulating peritoneal sclerosis (EPS) is an infrequent but serious complication of long-term peritoneal dialysis (PD). EPS may become clinically apparent when patients are on PD (classical EPS) or after undergoing kidney transplantation (post-transplantation EPS). This presentation of EPS seems to occur shortly after kidney transplantation in former PD patients. In this report, we present our experience in our first case of patient diagnosed with EPS after kidney transplantation.

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

A case of encapsulating peritoneal sclerosis in a patient with chronic schistosomiasis

•

Chronic schistosomiasis leads to immune dysregulation and organ fibrosis.

•

Encapsulating peritoneal sclerosis (EPS) is a potentially fatal condition, if left untreated.

•

Inflammatory pathways promote mesothelial proliferation leading to EPS development.

•

EPS has never been described in patients with chronic schistosomiasis.

•

A rare case of a patient with concurrent schistosomiasis and EPS is presented here.

Encapsulating peritoneal sclerosis (EPS) is a debilitating condition, mainly associated with long-term peritoneal dialysis, where up-regulation of intra-abdominal inflammatory pathways leads to a fibrocollagenous peritoneal membrane formation resembling a cocoon. EPS causes intestinal encapsulation leading to bowel obstruction and dilatation. Chronic schistosomiasis is characterized by dysregulation of pro-inflammatory and anti-inflammatory cytokines. EPS has never been reported before in patients with chronic schistosomiasis. We report the first, to our knowledge, case of a 57-year-old male originated from Burkina Faso with chronic intestinal and urogenital schistosomiasis and EPS. Although causality cannot be established solely by this case, we hypothesize that EPS may be the result of chronic inflammatory activation, due to immune dysregulation driven by chronic schistosomiasis. The potential pathogenetic linkage between these two conditions should be further explored.

Long-term outcomes in patients with encapsulating peritoneal sclerosis managed with nutritional support

BACKGROUND

Little is known about long-term survivors with encapsulating peritoneal sclerosis (EPS). Published literature focuses on patients managed surgically. We describe our experience of the long-term outcomes in patients with EPS conservatively managed with nutritional support alone.

METHODS

This is a single-centre retrospective observational study of patients who had survived for ≥5 years since diagnosis. EPS survivors were invited for review of symptoms, nutritional assessment and evaluation of quality of life. Radiological progression was assessed based on serial computed tomography (CT) scores for each patient.

RESULTS

A total of 23 patients with a diagnosis of EPS for at least 5 years were identified, with 18 patients alive at the time of the study. Of these 18 patients, 10 patients transferred to haemodialysis (HD) and 8 patients received kidney transplants. Commonest symptoms were nausea (91%) and vomiting (73%). Mean body mass index for patients was within the ideal and healthy range, with only 11% suffering from continued weight loss. In all, 70% EPS survivors on HD received nutritional support compared to 15% of those with transplants; 17% required ongoing parenteral nutrition. Of the 11 patients with serial CT scans at least 4 years apart, 10 had an increase in radiological score for EPS but with no apparent correlation to clinical outcomes. There were no significant differences in the reported quality of life between EPS survivors on HD and those transplanted, with self-rated health status equivalent to that reported for the general end-stage kidney disease (ESKD) population.

CONCLUSION

Long-term survival following EPS managed conservatively with nutritional support is feasible, with the majority no longer requiring nutritional support and having a quality of life similar to other patients with ESKD.

Imaging and treatment of idiopathic abdominal cocoon in 9 patients

The aim of the current study was to investigate the imaging features of abdominal cocoon (AC), the methods of diagnosis and treatment of AC and improve understanding of AC. To do this, the current study retrospectively analyzed the clinical data and imaging findings of nine patients with AC. The clinical manifestations included intestinal obstruction in six out of the nine cases of AC, which included two cases of bowel strangulation and five cases of soft masses in the abdomen. Imaging features of AC included the following: i) Bowel loops were usually present in a fixed cluster; ii) bowel loops were encapsulated partially or totally by a thickening fibrous membrane-like ‘cocoon’; iii) bowel wall thickened in the ‘cocoon’, and the bowel loops and sac adhered; iv) loculated ascites in the ‘cocoon’; v) abnormal clustering of the mesenteric vasculature, hypoplasia of the omentum majus was present or absent; and vi) Ileus occurred in some cases. The features of a plain abdominal X-ray, a gastrointestinal barium meal series and ultrasonography lacked specificity. The results of CT in eight out of nine cases of AC were consistent with the surgical findings. Surgery was the first choice of therapy. All cases were treated surgically, showing that the bowel loops were encapsulated partially or totally by a thickened fibrous membrane. All cases received operations including partial or total excision of the membrane and enterolysis. In conclusion, CT may be highly valuable in the preoperative diagnosis of AC.

Outcomes of the surgical management of encapsulating peritoneal sclerosis: A case series from a single center in Korea

Background

Encapsulating peritoneal sclerosis (EPS) is a rare but near-fatal complication of peritoneal dialysis (PD). Despite the high mortality rate of EPS, the surgical treatment strategy of severe EPS is yet to be established.

Methods

We retrospectively analyzed outcomes of patients with EPS who underwent enterolysis for intractable EPS at Seoul National University Hospital between 2001 and 2018. EPS was diagnosed based on the clinical symptoms and radiological findings of abdominal computed tomography (CT). CT scans were scored according to an EPS scoring system that assessed peritoneal thickening and calcification as well as bowel thickening, tethering, loculation, and dilatation.

Results

Thirteen patients (nine males and four females; age, 48 [29–63] years) underwent enterolysis for severe EPS. PD duration (11 [6–21] years) was not associated with survival. Two patients were newly diagnosed with EPS following kidney transplantation. Five patients died of infectious complications immediately after the surgery. Eight patients survived after the first surgery; however, five of them underwent reoperation but died of persistent infection, fistula formation, or adhesive bowel obstruction. Four young (< 60 years) male patients with relatively low CT scan scores (< 13) survived for > 2 years after the first surgery. Median survival duration from EPS diagnosis was 22 (1.3–184) months and that from the first surgery was 9 (0.3–153) months.

Conclusion

The high mortality rate of EPS suggests the importance of appropriate surgical intervention in young symptomatic male EPS patients with relatively low CT scan scores.

Clinical risk factors and outcomes of massive ascites accumulation after discontinuation of peritoneal dialysis

Background

Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis (PD), with high morbidity and mortality that requires an early diagnosis for effective treatment. PD withdrawal and bacterial peritonitis are important triggers for the onset of EPS. However, few studies have focused on cases of PD withdrawal without a clinical diagnosis of peritonitis, cirrhosis, or carcinomatosis. We aimed to compare the clinical characteristics and computed tomography (CT) images of patients with or without ascites in such situations and assess clinical outcomes in terms of mortality.

Methods

Our retrospective review included 78 patients who withdraw PD between January 2000 and December 2017.

Results

Ten patients had ascites, and 68 did not have a significant intra-abdominal collection. The ascites group had a significantly longer PD duration (months; 134.41 [range, 35.43–181.80] vs. 32.42 [733–183.47], p < 0.001) and higher peritoneal membrane transport status based on the dialysate-to-plasma ratios of creatinine (0.78 ± 0.08 vs. 0.68 ± 0.11, p = 0.009) and glucose (0.27 ± 0.07 vs. 0.636 ± 0.08, p = 0.001) than the control group. CT parameters, including peritoneal calcification, thickness, bowel tethering, or bowel dilatation, were not all present in each patient with ascites and EPS. During the 12-month study period, the ascites group had a higher risk for developing EPS (70% vs. 0%, p < 0.001) and a higher 12-month all-cause mortality (30% vs. 0%, p = 0.002).

Conclusions

Ascites accumulation was not rare after PD discontinuation. A longer PD duration and high peritoneal membrane transport status could predict subsequent ascites accumulation. Furthermore, patients with ascites were at a higher risk of EPS.

Encapsulating Peritoneal Sclerosis: Pathophysiology and Current Treatment Options

Encapsulating peritoneal sclerosis (EPS) is a life-threatening complication of long-term peritoneal dialysis (PD), which may even occur after patients have switched to hemodialysis (HD) or undergone kidney transplantation. The incidence of EPS varies across the globe and increases with PD vintage. Causative factors are the chronic exposure to bioincompatible PD solutions, which cause long-term modifications of the peritoneum, a high peritoneal transporter status involving high glucose concentrations, peritonitis episodes, and smoldering peritoneal inflammation. Additional potential causes are predisposing genetic factors and some medications. Clinical symptoms comprise signs of intestinal obstruction and a high peritoneal transporter status with incipient ultrafiltration failure. In radiological, macro-, and microscopic studies, a massively fibrotic and calcified peritoneum enclosed the intestine and parietal wall in such cases. Empirical treatments commonly used are corticosteroids and tamoxifen, which has fibrinolytic properties. Immunosuppressants like azathioprine, mycophenolate mofetil, or mTOR inhibitors may also help with reducing inflammation, fibrin deposition, and collagen synthesis and maturation. In animal studies, N-acetylcysteine, colchicine, rosiglitazone, thalidomide, and renin-angiotensin system (RAS) inhibitors yielded promising results. Surgical treatment has mainly been performed in severe cases of intestinal obstruction, with varying results. Mortality rates are still 25–55% in adults and about 14% in children. To reduce the incidence of EPS and improve the outcome of this devastating complication of chronic PD, vigorous consideration of the risk factors, early diagnosis, and timely discontinuation of PD and therapeutic interventions are mandatory, even though these are merely based on empirical evidence.

[Encapsulant peritonitis]

INTRODUCTION

Encapsulating peritonitis is a rare but severe chronic fibrotic condition related to the development of a white fibrous membrane surrounding the digestive tract. Idiopathic forms have been described, however the disease is most often secondary to peritoneal dialysis or more rarely to surgery. Treatment is difficult and not codified.

CASE REPORT

We report here the observation of a 36-year-old patient whose diagnosis of encapsulating peritonitis was made after a long sub-occlusive history, eight years after a gastric ulcer perforation.

DISCUSSION

We discuss the possible etiologies and we present a focus on this rare and little-known entity.

Surgical Treatment for Encapsulating Peritoneal Sclerosis: 24 Years’ Experience

Background

Encapsulating peritoneal sclerosis (EPS) is a serious complication of long-term peritoneal dialysis. The mortality rate for EPS is high, primarily due to complications related to bowel obstruction. Surgery was previously contraindicated; however, surgical enterolysis is performed for patients in whom bowel obstruction fails to improve.

Methods

This was a retrospective observational study of patients with EPS who received surgical intervention at a single center between November 1993 and October 2017. The severity of intestine damage was characterized by grade-3 peritoneal calcification on abdominal computed tomography (CT) scan and degeneration of the small intestinal wall in surgery.

Results

Two-hundred and forty-three patients with EPS opted for surgery. Among them, 58 had recurrence and required re-surgery; a total of 318 EPS surgeries were performed. Death was related to EPS in 61 patients (25.1%), of whom 15 died postoperatively. Sixty-seven patients (27.6%) died from other causes. The actuarial survival rates at 1, 2, 3, 5, and 8 years after EPS diagnosis were 91%, 83%, 77%, 66%, and 53% respectively. The 50% actuarial survival points after EPS diagnosis and surgery were 104 months and 85 months, respectively. Peritoneal calcification and small intestinal wall degeneration grading showed significant association with the mortality curve for EPS-related death.

Conclusion

Excellent outcomes for EPS are achieved with surgery. The degree of peritoneal deterioration affected the clinical outcomes. Currently, EPS is no longer recognized as a fatal complication.

Early Detection of Imminent Encapsulating Peritoneal Sclerosis: Free Water Transport, Selected Effluent Proteins, or Both?

Background

No diagnostic tool or methodology is currently available for early detection of imminent encapsulating peritoneal sclerosis (EPS). The objective of this study was to investigate the predictive value of free water transport (FWT) and construct a panel of peritoneal effluent proteins for EPS alone or in combination with FWT. These parameters could be incorporated in the follow-up of peritoneal dialysis (PD) patients.

Methods

A case-control study, nested in a longitudinal PD patient cohort, was conducted. Time-specific areas under the receiver operating characteristic (ROC) curve were calculated for FWT and effluent biomarkers at a lag time up to 3 years before EPS diagnosis. Free water transport was combined with appearance rates (AR) of biomarkers to assess their clinical validity.

Results

Free water transport volume and AR of effluent bio-markers were investigated in 11 EPS patients and 34 long-term PD patients. Diagnostic performance was best for FWT (area under the curve [AUC] 0.94) followed by plasminogen activator inhibitor (PAI-1) AR. Throughout, diagnostic panels of FWT and AR of cancer antigen 125 (CA125), interleukin-6 (IL-6), or (PAI-1) yielded specificity estimates above 84%. The combination of FWT and PAI-1 AR identified the largest proportion of EPS patients at 1 year prior to diagnosis (sensitivity 100%, specificity 94%).

Conclusion

Measurement of FWT is simple and has the highest predictive value for imminent EPS. The addition of effluent biomarkers provides an all-round insight into the state of the peritoneum. Our data indicate that combining FWT with either PAI-1, CA125, or IL-6 has the highest specificity. This is required to avoid unnecessary discontinuation of PD treatment.

Encapsulating Peritoneal Sclerosis: The Abdominal Cocoon

Encapsulating peritoneal sclerosis (EPS) is a rare but serious condition that results in (a) encapsulation of bowel within a thickened fibrocollagenous peritoneal membrane and (b) recurrent episodes of bowel obstruction. Although described by various names in the literature, the preferred term is encapsulating peritoneal sclerosis because it best describes the morphologic and histologic changes in this disorder. The etiology of EPS is multifactorial, with a wide variety of implicated predisposing factors that disrupt the normal physiologic function of the peritoneal membrane-prime among these factors being long-term peritoneal dialysis and bacterial peritoneal infections, especially tuberculosis. The clinical features of EPS are usually nonspecific, and knowledge of the radiologic features is necessary to make a specific diagnosis. The findings on radiographs are usually normal. Images from small-bowel follow-through studies show the bowel loops conglomerated in a concertina-like fashion with a serpentine arrangement in a fixed U-shaped configuration. US demonstrates a "cauliflower" appearance of bowel with a narrow base, as well as a "trilaminar" appearance depicted especially with use of high-resolution US probes. CT is the imaging modality of choice and allows identification of the thickened contrast material-enhanced abnormal peritoneal membrane and the encapsulated clumped bowel loops. In addition, CT can potentially help identify the cause of EPS (omental granuloma in tuberculosis), as well as the complications of EPS (bowel obstruction). Conservative medical treatment and surgical therapy early in the course of EPS have been used for management of the condition. The purpose of this article is to review the nomenclature and etiopathogenesis of EPS, describe the multimodality imaging appearances of EPS, including differentiating its features from those of other conditions mimicking EPS, and give an overview of management options. Online DICOM image stacks are available for this article. ^©RSNA, 2018.

Encapsulating Peritoneal Sclerosis

Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of peritoneal dialysis. In this review, we describe the clinical picture and histologic changes to the peritoneal membrane that are associated with EPS and provide an update on current diagnosis and management. We also discuss the recent studies that have suggested that the use of more biocompatible solutions containing lower concentrations of glucose degradation product that often are pH neutral in combination with a change in clinical practice (reducing glucose exposure and monitoring peritoneal membrane function) might ameliorate peritoneal degeneration, reduce the incidence of EPS, and minimize the severity of the disease.

Incidence and outcomes of encapsulating peritoneal sclerosis (EPS) and factors associated with severe EPS

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of long-term peritoneal dialysis (PD). However, previous studies reported large variations in its mortality rates that may associate with a different degree of EPS severity. This study reports the incidence and outcomes of EPS and identifies the risk factors associated with severe EPS.

METHODS

We retrospectively analyzed clinical data of EPS patients from 3 medical centers in Taiwan from January 1982 to September 2015, and classified patients as having mild/moderate or severe EPS. Patients with intractable intestinal obstruction/gut-related sepsis that needed surgical intervention or resulted in mortality were in severe EPS group. Follow-up for outcome was through December 31, 2015. Clinical characteristics, peritoneal dialysis (PD)-related parameters, biochemical and imaging results were analyzed and compared between groups.

RESULTS

Fifty-eight of 3202 patients undergoing PD during the study period had EPS (prevalence 1.8%). The incidence of EPS increased for patients on PD for >6-8 years (≤6 yrs. vs. >6-8 yrs., 0.0% vs. 1.8%, p = 0.001). Relative to those on PD for >6-8 years, the risk of EPS significantly increased with PD duration longer than 10 years (>10-12 years vs. >6-8 years: OR: 5.5, 95% CI: 1.7-17.1, p < 0.01). Twenty-three patients fulfilled the criteria for severe EPS. The overall mortality rate of EPS was 35% (20/58), and was 74% (17/23) in the severe EPS group. The average serum levels of C-reactive protein (CRP) and intact-parathyroid hormone (i-PTH), which were checked every 3~6 months within one year before diagnosis of EPS, were higher in severe EPS group than in mild/moderate group (p = 0.02, p = 0.08, respectively). Multivariate analysis revealed severe EPS was independently associated with bowel tethering (based on CT), presentation with bloody ascites, diagnosis of EPS after withdrawal from PD, and i-PTH ≥ 384 pg/mL. Receiver operating characteristic analysis indicated that presentation with 2 or more of the 5 risk factors (EPS diagnosis after PD withdrawal, bloody ascites, bowel tethering, CRP ≥ 29 mg/L, and i-PTH ≥ 384 pg/mL) had a good accuracy (AUC = 0.80, p = 0.001) for prediction of severe EPS.

CONCLUSIONS

The incidence of EPS increases with PD duration. Severe EPS has high mortality rate and is associated with bowel tethering, presentation of bloody ascites, diagnosis after PD withdrawal, and higher serum levels of i-PTH before EPS diagnosis. Having 2 or more of the 5 risk factors can provide a good accuracy for prediction of severe EPS.

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.

Absence of Post-Transplantation Encapsulating Peritoneal Sclerosis after Relatively Short Exposure to Peritoneal Dialysis: Prospective Analysis Using Repeated Abdominal CT Scanning

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is the most severe complication of peritoneal dialysis (PD). Several retrospective reports published between 2007 and 2009 have suggested an increasing incidence of EPS occurring after kidney transplantation. We conducted a prospective observational study to determine the incidence of post-transplantation EPS and identify possible risk factors.

METHODS

Consecutive PD patients undergoing kidney transplantation between 2009 and 2013 were included. Encapsulating peritoneal sclerosis was defined as gastrointestinal obstruction combined with radiological evidence of EPS. Gastrointestinal symptoms were assessed using a self-administered Gastrointestinal Symptom Rating Scale (GSRS) questionnaire. Abdominal computed tomography (CT) was performed prospectively at 6 and 18 months post-transplantation. The primary end point was EPS during follow-up.

RESULTS

Fifty-three PD patients were included (age 51 ± 14 years). Mean PD duration was 31.3 months. Peritoneal dialysis solutions low in glucose degradation products and icodextrin were used by 86.8% of patients. A fast or average-fast transport status was documented in 83.0%. After a median follow-up of 19 months, complete data of 47 patients were available for analysis. None of the patients developed clinical or radiological signs of EPS. The GSRS score improved from 1.87 to 1.55 (p = 0.024) and body weight increased from 75.9 to 78.3 kg (p = 0.003). Only 1 patient had new onset localized (< 20%) peritoneal thickening on CT 22 months post-transplantation.

CONCLUSION

Post-transplantation EPS did not develop in this cohort of patients with a relatively short time of PD exposure. This suggests that these patients can be transplanted safely without concern for the development of EPS, at least within the follow-up period of 19 months.

A prospective, proteomics study identified potential biomarkers of encapsulating peritoneal sclerosis in peritoneal effluent

Encapsulating peritoneal sclerosis (EPS) is a potentially devastating complication of peritoneal dialysis (PD). Diagnosis is often delayed due to the lack of effective and accurate diagnostic tools. We therefore examined peritoneal effluent for potential biomarkers that could predict or confirm the diagnosis of EPS and would be valuable in stratifying at-risk patients and driving appropriate interventions. Using prospectively collected samples from the Global Fluid Study and a cohort of Greek PD patients, we utilized 2D SDSPAGE/ MS and iTRAQ to identify changes in the peritoneal effluent proteome from patients diagnosed with EPS and controls matched for treatment exposure. We employed a combinatorial peptide ligand library to compress the dynamic range of protein concentrations to aid identification of low-abundance proteins. In patients with stable membrane function, fibrinogen γ-chain and heparan sulphate proteoglycan core protein progressively increased over time on PD. In patients who developed EPS, collagen-α1(I), γ-actin and Complement factors B and I were elevated up to five years prior to diagnosis. Orosomucoid-1 and a2-HS-glycoprotein chain-B were elevated about one year before diagnosis, while apolipoprotein A-IV and α1-antitrypsin were decreased compared to controls. Dynamic range compression resulted in an increased number of proteins detected with improved resolution of protein spots, compared to the full fluid proteome. Intelectin-1, dermatopontin, gelsolin, and retinol binding protein-4 were elevated in proteome-mined samples from patients with EPS compared to patients that had just commenced peritoneal dialysis. Thus, prospective analysis of peritoneal effluent uncovered proteins indicative of inflammatory and pro-fibrotic injury worthy of further evaluation as diagnostic/prognostic markers.

Can radiological assessment of abdominal computerized scans diagnose encapsulating peritoneal sclerosis in long-term peritoneal dialysis patients?

AIM

Encapsulating peritoneal sclerosis (EPS) is a rare but potentially devastating complication of long-term peritoneal dialysis (PD). Changes to the peritoneal membrane occur with duration of PD therapy. To determine the potential effect of prospective computerized tomography (CT) scanning, we reviewed the scans of patients who had developed EPS compared with those without EPS.

METHODS

We retrospectively compared CT scans that had been prospectively performed in a screening program for PD patients after 4 years of PD and compared scans from 18 patients with confirmed EPS and 26 vintage matched controls without EPS. Anonymized scans were reported independently by two blinded experienced radiologists.

RESULTS

Peritoneal thickening, calcification, bowel tethering, thickening and dilatation were significantly more commonly reported in the EPS group. Total combined radiological scores, also including septation within peritoneal fluid, were significantly higher in the EPS group and the greatest for those who died as a consequence of EPS. Simplified scoring based on presence or absence, then for a score of ≥3.0, gave a receiver operating characteristic value of 0.87 for EPS, with a sensitivity of 78% and specificity of 85%, respectively. Inter-observer agreement varied from poor to good, being the greatest for calcification and bowel dilatation and the lowest for peritoneal thickening.

CONCLUSION

CT scan reporting can differentiate EPS from peritoneal changes associated with duration of PD therapy. Severity of abnormalities was associated with clinical outcomes. However, inter-observer agreement varies with different radiological appearances, and future studies are required to determine weighting of radiological changes to provide prognostic information for clinicians and patients.

Idiopathic Sclerosing Encapsulating Peritonitis: A Rare Cause of Subacute Intestinal Obstruction

We present a case of a previously healthy 50-year-old gentleman who had recurrent vomiting and abdominal pain of two-month duration. The patient was subsequently diagnosed with abdominal cocoon on computed tomography. Idiopathic sclerosing encapsulating peritonitis, also known as abdominal cocoon, is a rare cause of small bowel obstruction. Visualization of variable encasement of the small bowel loops by a characteristic membranous sac, either preoperatively with cross-sectional imaging or intraoperatively, is the key to diagnosis. This is a highly treatable condition; surgical excision of the sac with adhesiolysis facilitates a full recovery in affected patients.

Incidence and outcome of encapsulating peritoneal sclerosis

Background

Studies report variation in the incidence and outcomes of encapsulating peritoneal sclerosis (EPS). This study reports the incidence and outcome of EPS cases in a national cohort of peritoneal dialysis (PD) patients.

Methods

The incident cohort of adult patients who started PD between 1 January 2000 and 31 December 2007 in Scotland (n = 1238) was identified from the Scottish Renal Registry. All renal units in Scotland identified potential EPS cases diagnosed from 1 January 2000 to 31 December 2014, by which point all patients had a minimum of 7 years follow-up from start of PD.

Results

By 31 December 2014, 35 EPS cases were diagnosed in the 1238 patient cohort: an overall incidence of 2.8%. The incidence for subgroups with longer PD duration rises exponentially: 1.1% by 1 year, 3.4% by 3 years, 8.8% at 4 years, 9.4% at 5 years and 22.2% by 7 years. Outcomes are poor with mortality of 57.1% by 1 year after diagnosis. Survival analysis demonstrates an initial above-average survival in patients who later develop EPS, which plummets to well below average after EPS diagnosis.

Conclusions

The incidence of EPS is reassuringly low provided PD exposure is not prolonged and this supports ongoing use of PD. However, continuing PD beyond 3 years results in an exponential rise in the risk of developing EPS and deciding whether this risk is acceptable should be made on an individual patient basis.

Vascular Endothelial Cell Injury Is an Important Factor in the Development of Encapsulating Peritoneal Sclerosis in Long-Term Peritoneal Dialysis Patients

Background and Objectives

Encapsulating peritoneal sclerosis (EPS) is a rare but serious and life-threatening complication of peritoneal dialysis (PD). However, the precise pathogenesis remains unclear; in addition, predictors and early diagnostic biomarkers for EPS have not yet to be established.

Methods

Eighty-three peritoneal membrane samples taken at catheter removal were examined to identify pathological characteristics of chronic peritoneal deterioration, which promotes EPS in patients undergoing long-term PD treatment with low occurrence of peritonitis.

Results

According to univariable logistic regression analysis of the pathological findings, thickness of the peritoneal membrane (P = 0.045), new membrane formation score (P = 0.006), ratio of luminal diameter to vessel diameter (L/V ratio, P<0.001), presence of CD31-negative vessels (P = 0.021), fibrin deposition (P<0.001), and collagen volume fraction (P = 0.018) were associated with EPS development. In analyses of samples with and without EPS matched for PD treatment period, non-diabetes, and PD solution, univariable analysis identified L/V ratio (per 0.1 increase: odds ratio (OR) 0.44, P = 0.003) and fibrin deposition (OR 6.35, P = 0.027) as the factors associated with EPS. L/V ratio was lower in patients with fibrin exudation than in patients without fibrin exudation.

Conclusions

These findings suggest that damage to vascular endothelial cells, as represented by low L/V ratio, could be a predictive finding for the development of EPS, particularly in long-term PD patients unaffected by peritonitis.

Encapsulating peritoneal sclerosis: surgery, sustained drug therapy and treatment of recurrence at 1 year

A 74-year-old woman with end-stage renal disease presented with clinical symptoms of encapsulating peritoneal sclerosis 2 years after switching from peritoneal dialysis to haemodialysis. Imaging revealed a large cystic structure in her abdomen and her final diagnosis was made by exploratory laparotomy. A 10 cm×15 cm fibrous rind was excised from the peritoneum and the patient was subsequently started on tamoxifen 20 mg daily and prednisone 20 mg daily. Given her reduction in clinical symptoms and concerns about the long-term effects of corticosteroids, prednisone was tapered and she remained on tamoxifen monotherapy. 1 year postsurgery, she presented with symptoms of nausea, vomiting and anorexia. A repeat CT of the abdomen confirmed a recurrence of encapsulating peritoneal sclerosis. Prednisone and tamoxifen were restarted at increased dosages of 25 and 40 mg daily, respectively. The patient's symptoms were ameliorated within 2 weeks of drug therapy modification.

C-reactive protein levels in combination with abdominal CT scans is a useful tool to predict the macroscopic appearance in late-stage EPS patients prior to surgery

Background

Diagnosis of encapsulating peritoneal sclerosis (EPS) is based on clinical symptoms, radiologic findings, and macroscopic or histological criteria. Two diagnostic scores for radiologic findings in computed tomography (CT) scans of patients with EPS have been established in the past (by Tarzi et al and Vlijm et al). The macroscopic appearance of EPS has previously been separated into three types. The use of CT scan as a tool to predict different macroscopic phenotypes, leading to specific surgical techniques and different medical treatment, has not yet been investigated.

Methods

We retrospectively analyzed 30 patients with late-stage EPS who underwent major surgery with peritonectomy and enterolysis. The preoperative CT scans were scored according to the two aforementioned established diagnostic CT scores. The macroscopic phenotype, surgical procedure, and laboratory values at the time of surgery were evaluated. CT findings in the different macroscopic phenotypes were analyzed.

Results

All patients had highly predictive CT scores for EPS. The macroscopic Type III had significantly higher CT scores compared with the other macroscopic phenotypes. Patients with macroscopic Type I had significantly higher C-reactive protein values compared to EPS Type III. Operation time was significantly longer, and repeated surgery and intraoperative complications were more frequent in EPS Type I compared with EPS Type III (P<0.05). Using the CT score and CRP level, the sensitivities for prediction of EPS I and III were 78% and 87% with corresponding specificities of 67% and 93%.

Conclusion

Abdominal CT scans might help to identify patients with a higher risk of complications and provide important information for the surgical intervention prior to surgery.

Pelvic drainage during removal of dialysis catheter decreases the risk of subsequent intra-abdominal complications in refractory peritoneal dialysis-related peritonitis

AIM

Some patients with refractory peritoneal dialysis-related peritonitis continue to develop intra-abdominal complications despite removal of the peritoneal catheter. Repeated percutaneous drainage or open laparotomy is often required, and mortality is not uncommon. The benefits of pelvic drainage placement during catheter removal in decreasing these complications and interventions remain unproven.

METHODS

Forty-six patients with refractory peritonitis who underwent removal of a Tenckhoff catheter between 1991 and 2013 were reviewed retrospectively. Twelve patients had pelvic drainage using closed active suction devices during catheter removal (drainage group). The remaining 34 patients underwent catheter removal without drainage (non-drainage group). The outcomes measured were the development of intra-abdominal complications and the requirement for repeated percutaneous drainage or open laparotomy within 90 days after the catheter removal.

RESULTS

Baseline characteristics were similar with the exception of a higher median number of previous peritonitis episodes in the drainage group compared with the non-drainage group (2 vs 0, P = 0.02). During the follow-up period, intra-abdominal complications occurred in 15 (44%) of 34 patients in the non-drainage group, compared with one (8%) of 12 patients in the drainage group (P = 0.03). Twelve (35%) patients in the non-drainage group required repeated percutaneous drainage or open laparotomy for management, compared with zero (0%) patients in the drainage group (P = 0.02). Drain tubes were removed at a median of 6 days (inter-quartile range: 5-10) without complications.

CONCLUSIONS

In the management of refractory peritonitis, pelvic drainage during removal of dialysis catheter decreases the risk of subsequent intra-abdominal complications and invasive interventions.

An unusual case of extensive peritoneal calcification: A case report

The peritoneum is the largest serous membrane of the body and can be exposed to several injuries that may cause abnormal findings on imaging exams. Linear peritoneal calcification is remarkably rare, usually secondary to long duration peritoneal dialysis. We report an uncommon case of extensive peritoneal calcification in a 39-year-old female without long exposure to peritoneal dialysis solutions, in which peritoneal calcification could be linked to Alport syndrome and previous adverse reaction to intraperitoneal iodinated contrast. Radiologist should be aware of this and related imaging findings, know when to search for them as well as understand their clinical value.

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.

Histological and clinical findings in patients with post-transplantation and classical encapsulating peritoneal sclerosis: a European multicenter study

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) commonly presents after peritoneal dialysis has been stopped, either post-transplantation (PT-EPS) or after switching to hemodialysis (classical EPS, cEPS). The aim of the present study was to investigate whether PT-EPS and cEPS differ in morphology and clinical course.

METHODS

In this European multicenter study we included fifty-six EPS patients, retrospectively paired-matched for peritoneal dialysis (PD) duration. Twenty-eight patients developed EPS after renal transplantation, whereas the other twenty-eight patients were classical EPS patients. Demographic data, PD details, and course of disease were documented. Peritoneal biopsies of all patients were investigated using histological criteria.

RESULTS

Eighteen patients from the Netherlands and thirty-eight patients from Germany were included. Time on PD was 78(64-95) in the PT-EPS and 72(50-89) months in the cEPS group (p>0.05). There were no significant differences between the morphological findings of cEPS and PT-EPS. Podoplanin positive cells were a prominent feature in both groups, but with a similar distribution of the podoplanin patterns. Time between cessation of PD to the clinical diagnosis of EPS was significantly shorter in the PT-EPS group as compared to cEPS (4(2-9) months versus 23(7-24) months, p<0.001). Peritonitis rate was significantly higher in cEPS.

CONCLUSIONS

In peritoneal biopsies PT-EPS and cEPS are not distinguishable by histomorphology and immunohistochemistry, which argues against different entities. The critical phase for PT-EPS is during the first year after transplantation and therefore earlier after PD cessation then in cEPS.