Single-center experience of encapsulating peritoneal sclerosis in patients on peritoneal dialysis for end-stage renal failure

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.

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.

Risk factors for Encapsulating Peritoneal Sclerosis in patients undergoing peritoneal dialysis: A meta-analysis

Purpose

Encapsulating Peritoneal Sclerosis (EPS) is the most serious complication of long-term peritoneal dialysis (PD), which considerably reduces the patient’s quality of life, leading to patients discontinuing PD. Considering these negative effects, it is necessary to systematically review and determine the risk factors of EPS.

Methods

The PubMed, Embase, Web of Science, Cochrane Library, and China Biology Medicine (CBM) were searched from their inception to January 1st, 2022, and the bibliographies from the citations of relevant articles were manually searched. The ROBINS-I (Risk of Bias in Non-randomized studies of Interventions) tool was used to evaluate the risk of bias of included studies.

Results

Ten studies involving 12595 participants were included in this meta-analysis. The results revealed that a younger age at PD onset (MD = -7.70, 95% CI, -11.53~-3.86), a higher transporter (MD = 0.13, 95% CI, 0.09~0.18), a longer PD duration (SMD = 1.15, 95% CI, 0.68~1.61), a longer peritonitis duration (MD = 12.66, 95% CI, 3.85~21.47), and history of glomerulonephritis (OR = 1.42, 95% CI, 1.02~1.97) were significant risk factors for EPS. However, sex, use of icodextrin, the number of peritonitis episodes, and history of multicystic kidney disease did not affect the risk of EPS.

Conclusions

This review provides a scientific basis for further understanding the etiology of PD-related EPS and improving prevention strategies. More high-quality studies are necessary to validate this paper’s findings.

Impact of Metabolomics Technologies on the Assessment of Peritoneal Membrane Profiles in Peritoneal Dialysis Patients: A Systematic Review

Peritoneal dialysis (PD) is an effective and frequent dialysis modality in adults, particularly preferred in infants and young children with end-stage renal disease (ESRD). Long-term exposure of the peritoneal membrane to dialysis solutions results in severe morphologic and functional alterations. Peritoneal dialysis effluent biomarkers are based on omics technologies, which could predict the onset or confirm the diagnosis of peritoneal membrane dysfunction, would allow the development of accurate early prognostic tools and, potentially, the identification of future therapeutic targets. The purpose of our study was to critically review the literature on the impact and the effectiveness of metabolomics technologies in peritoneal health. The main search was performed in electronic databases (PubMed/MEDLINE, Embase and Cochrane Central Register of Controlled Trials) from inception to December 2020, using various combinations of Medical Subject Headings (MeSH). The main search highlighted nine studies, of which seven were evaluated in detail. Metabolomics technologies may provide significant input in the recognition of peritoneal membrane dysfunction in PD patients and provide evidence of early intervention strategies that could protect peritoneum health and function.

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.

Risk factors and clinical outcomes of encapsulating peritoneal sclerosis: A case-control study from China

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is an uncommon, but serious complication in patients with continuous ambulatory peritoneal dialysis (PD) who have a considerable mortality rate. This study aimed to identify risk factors and outcomes of EPS in Chinese patients on PD.

METHODS

Sixteen patients on PD who met the International Society for Peritoneal Dialysis criteria for diagnosis of EPS in the First Affiliated Hospital of Sun Yat-Sen University from 1997 to 2018 were included. Patients without EPS were matched for age, sex and the duration of PD and selected at a 1:3 ratio for the controls. A case-control study was conducted to analyse the clinical profile and risk factors associated with EPS in patients.

RESULTS

The prevalence of EPS in patients on PD in our centre was 0.55%. The percentage of EPS significantly increased with the duration of PD. In univariate regression analysis, a history of peritonitis (odds ratios (OR): 2.83; 95% confidence interval (CI): 0.82-9.68; p = 0.08), peritoneal glucose exposure (OR: 1.12; 95% CI: 1.03-1.22; p < 0.01) and a high peritoneal transport status (OR: 14.70; 95% CI: 1.85-117.02; p < 0.01) were associated with EPS in patients on PD. However in the multivariate model, only a high peritoneal transport status (adjusted odds ratios (aOR): 13.65; 95% CI: 1.69-109.96; p = 0.01) was independently associated with EPS.

CONCLUSION

The rate of EPS significantly increases with the duration of PD. Progressive peritoneal dysfunction, especially a high peritoneal transport status, is associated with a higher risk of EPS in this population.

In Vitro Study of Peritoneal Fibrosis

Peritoneal fibrosis (PF) is an important issue in peritoneal dialysis (PD) because it remains one of the leading causes of patient drop-out from PD. In this review, we focus on in vitro approaches to the pathogenesis and therapeutic potential of PF and on associated clinical implications. Representative Asian studies, initiated since mid-1990s, that have investigated matrix accumulation in peritoneal tissue possibly leading to PF in the PD population will be highlighted as examples to learn how to apply this research tool. As compared with data from well-designed clinical trials, observations from in vitro models may be far from becoming solid evidence; however, they do cast new light on options for investigations into therapeutic pharmaceuticals.

Treatments and outcomes of encapsulating peritoneal sclerosis in patients undergoing peritoneal dialysis: 295 cases from a nationwide inpatient database in Japan

BACKGROUND

The number of patients undergoing renal replacement therapy is increasing. We evaluated the practice patterns and outcomes of encapsulating peritoneal sclerosis (EPS) in patients undergoing peritoneal dialysis.

METHODS

Using a Japanese national inpatient database, we identified 295 patients with EPS who were hospitalized from July 2010 to March 2017. We categorized them into four groups: those who underwent surgery only (n = 39), those who received corticosteroid treatment only (n = 70), those who underwent both (n = 30), and those who underwent neither (n = 156). We investigated their characteristics, treatments, and outcomes.

RESULTS

More than half of patients were males and never-smokers and had a normal body mass index. Patients tended to undergo parenteral nutrition for 2 months. The proportions of emergency admission, intensive care unit (ICU) admission, central venous catheterization, catecholamine use, mechanical ventilation, and continuous hemodiafiltration were significantly different among the four groups (61%, 8.1%, 37.0%, 44.0%, 8.8%, and 5.8%, respectively). The both-treatment group had a significantly longer hospital stay (37.0 vs. 37.5 vs. 72.5 vs. 31.0 days, p < 0.001) and higher costs (US$16,554 vs. US$17,029 vs. US$33,757 vs. US$13,983, p < 0.001) than the other groups. In total, 52 patients (18%) died during hospitalization. There was no significant difference in inhospital complications and death, discharge status, 30-day readmission, or length of ICU stay among the four groups.

CONCLUSIONS

Our findings provide useful information for clinicians and patients hospitalized for treatment of EPS.

Nutritional Management of Patients Undergoing Surgery following Diagnosis with Encapsulating Peritoneal Sclerosis

Background

Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of peritoneal dialysis (PD). Gastrointestinal (GI) symptoms affect appetite and dietary intake. Adequate nutrition is especially important if surgical interventions are required.

Aim

To investigate the nutritional management of 23 EPS patients that underwent surgical intervention between 1999 and 2005 at Manchester Royal Infirmary, United Kingdom.

Methods

EPS was recognized by GI symptoms and diagnostically confirmed by laparotomy, computed tomographic scanning, or biopsy.

Results

Mean time on PD was 74 months (interquartile range 42 – 89 months). During the 12 months pre-diagnosis, 65% of the group showed significant weight loss ( p = 0.0001), with 8 patients losing >10% of body weight; 74% of patients experienced significant albumin decrease ( p = 0.001); and 56% of patients experienced GI symptoms during the 6 months pre-diagnosis. Nasogastric (NG) feeding was recommended for 8 patients but continued in only 1. 15 patients (mean albumin 27 g/L) commenced parenteral nutrition (PN); 9 patients recovered, with albumin increasing over the 6-month follow-up. Mean hospital time was 62 days for the group receiving neither NG nor PN, compared with 124.3 for the PN/NG group ( p = 0.04). In patients that died of EPS, albumin continued to fall at 3 months post-diagnosis.

Conclusion

There is currently little guidance for nutritional management of EPS. From this study we recommend ( 1 ) a high level of clinical suspicion for EPS, especially if PD patients have weight loss; ( 2 ) PN may be better than NG feeding but further studies into dual enteral nutrition and PN are needed; ( 3 ) aggressive nutritional supplementation pre- and postoperatively; and ( 4 ) dietitians need to recognize the high risk of refeeding syndrome.

Posttransplant Encapsulating Peritoneal Sclerosis: A Worrying New Trend?

Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication in patients on peritoneal dialysis (PD). We describe a cluster of 13 EPS cases occurring in 2 university hospitals in The Netherlands. Most of these cases were diagnosed after recent kidney transplantation, when the patients developed severe symptoms of bowel obstruction. This accumulation raised the question as to whether other than known risk factors, such as duration of PD treatment, could be involved in the development or course of EPS after transplantation. According to various publications, EPS has been diagnosed often after withdrawal from PD, suggesting that cessation in itself may be a risk factor. In addition, transplantation-related management should be considered to play a role, including the use of the profibrotic calcineurin inhibitors and the trend to reduce the load of corticosteroids in treatment regimes. To identify risk factors, further multicenter studies are required, paying special attention to alterations in immunosuppressive treatment regimens as well as PD prescriptions, including PD fluid characteristics. Transfer from PD to hemodialysis should be under serious consideration in patients eligible for kidney transplantation as soon as there are indications of ultrafiltration failure.

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.

Liver Infarction and Venous Thromboembolism after Tamoxifen Use in an ADPKD Patient with Encapsulating Peritoneal Sclerosis: A Case Report

Encapsulating peritoneal sclerosis (EPS) is a potentially fatal complication after long-term peritoneal dialysis, and tamoxifen can be used for its prevention and treatment. However, tamoxifen is known to increase the risk of venous thromboembolism. A 49-year-old woman was admitted with sudden abdominal pain. The patient had received peritoneal dialysis for 20 years and switched to hemodialysis after the diagnosis of EPS. Tamoxifen (10mg) and prednisolone (20mg) had been administered for 8 months. On computed tomography, the left hepatic lobe was hardly illuminated, leading to a diagnosis of liver infarction. A month later, she was re-admitted due to abdominal pain and extensive deep vein thrombosis of the leg. The administration of tamoxifen was stopped and prednisolone was reduced to 10mg. As her malnutrition progressed, she succumbed to death of gram negative sepsis. The patient was concluded to have liver infarction and extensive venous thrombosis as a side effect of tamoxifen.

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.

Adoptive transfer of DMSO-induced regulatory T cells exhibits a similar preventive effect compared to an in vivo DMSO treatment for chemical-induced experimental encapsulating peritoneal sclerosis in mice

Encapsulating peritoneal sclerosis (EPS) is a severe complication of peritoneal dialysis (PD). This disease leads to intestinal obstruction with or without peritonitis. The imbalance between the populations of Th17 and regulatory T (Treg) cells (higher Th17 cells and lower Treg cells) is part of the pathogenesis of EPS formation. We demonstrated that dimethyl sulfoxide (DMSO) effectively inhibited autoimmune diabetes recurrence in the islet transplantation of NOD mice via the induction of the differentiation of Treg cells. In this study, we investigated the therapeutic potential of DMSO in the inhibition of EPS formation by a mouse model. Under DMSO treatment, the thickening of the parietal and visceral peritoneum was significantly reduced. The populations of CD4, CD8, and IFN-γ-producing CD4 and CD8 T cells were decreased. The populations of IL-4-producing CD4 T lymphocytes, IL-10-producing CD4 T lymphocytes, CD4 CD69 T lymphocytes and Treg lymphocytes were increased. The expression levels of the cytokines IFN-γ, IL-17a, TNF-α and IL-23, in ascites, were significantly decreased following the DMSO treatment. Furthermore, the differentiation of Treg cells was induced by DMSO from naïve CD4 T cells in vitro, and these cells were adoptively transferred into the EPS mice and significantly prevented EPS formation, exhibiting a comparable effect to the in vivo DMSO treatment. We also demonstrated that the differentiation of Treg cells by DMSO occurred via the activation of STAT5 by its epigenetic effect, without altering the PI3K-AKT-mTOR or Raf-ERK pathways. Our results demonstrated, for the first time, that in vivo DMSO treatment suppresses EPS formation in a mouse model. Furthermore, the adoptive transfer of Treg cells that were differentiated from naïve CD4 T cells by an in vitro DMSO treatment exhibited a similar effect to the in vivo DMSO treatment for the prevention of EPS formation.

A high-density collagen xerogel thread prevents the progression of peritoneal fibrosis

An inserted high-density collagen xerogel thread prevents pathological fibrosis through the inhibition of inflammation and stromal cell proliferation in the peritoneum.

Tamoxifen attenuates dialysate-induced peritoneal fibrosis by inhibiting GSK-3β/β-catenin axis activation

Peritoneal fibrosis is a severe complication arising from long-term peritoneal dialysis (PD). Tamoxifen (Tamo) has been clinically proven effective in a series of fibrotic diseases, such as PD-associated encapsulating peritoneal sclerosis (EPS), but the mechanisms underlying Tamoxifen’s protective effects are yet to be defined. In the present study, C57BL/6 mice received intraperitoneal injections of either saline, 4.25% high glucose (HG) PD fluid (PDF) or PDF plus Tamoxifen each day for 30 days. Tamoxifen attenuated thickening of the peritoneum, and reversed PDF-induced peritoneal expression of E-cadherin, Vimentin, matrix metalloproteinase 9 (MMP9), Snail, and β-catenin. Mouse peritoneal mesothelial cells (mPMCs) were cultured in 4.25% glucose or 4.25% glucose plus Tamoxifen for 48 h. Tamoxifen inhibited epithelial-to-mesenchymal transition (EMT) as well as phosphorylation of glycogen synthase kinase-3β (GSK-3β), nuclear β-catenin, and Snail induced by exposure to HG. TWS119 reversed the effects of Tamoxifen on β-catenin and Snail expression. In conclusion, Tamoxifen significantly attenuated EMT during peritoneal epithelial fibrosis, in part by inhibiting GSK-3β/β-catenin activation.

Risk factors for encapsulating peritoneal sclerosis: Analysis of a 36-year experience in a University Hospital

AIM

Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication that occurs in peritoneal dialysis (PD) therapy. The present study aimed to identify the risk factors, especially peritonitis and biocompatible PD fluid.

METHODS

The study included 703 patients who received PD between January 1980 and March 2015 at two centres. The patients were divided into two groups: those who had developed EPS (EPS group: n = 44) and those who had no documentary evidence of EPS (non-EPS group: n = 659). The independent risks of EPS were determined by univariate and multivariate logistic models.

RESULTS

Encapsulating peritoneal sclerosis occurred in 44/703 (6.3%) patients between January 1980 and March 2015. In multivariate logistic models of risk factors correlated with EPS, dialysate to plasma creatinine ratio (D/P Cr) by peritoneal equilibration test (PET) and history of peritonitis were risk factors for EPS development (P < 0.01, respectively) in addition to PD duration. Especially, total duration of peritonitis, defined by period between onset and resolution of peritonitis, was an important risk factor for EPS development in patients with a history of peritonitis. Receiver operating characteristic (ROC) curve analysis revealed that cut-off point for EPS development was 36 days. Moreover, biocompatible PD fluid contributed to decreased EPS development.

CONCLUSION

Both the longer duration of peritonitis and higher D/P Cr, as well as the longer PD duration, were risk factors for EPS development. Furthermore, use of biocompatible PD fluid contributed to the decrease in EPS development.

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.

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.

Recommendations for pathological diagnosis on biopsy samples from peritoneal dialysis patients

Peritoneal dialysis (PD) has been established as an essential renal replacement therapy for patients with end stage renal disease during the past half century. Histological evaluation of the peritoneal membrane has contributed to the pathophysiological understanding of PD-related peritoneal injury such as peritonitis, fibrosis, and encapsulating peritoneal sclerosis (EPS). Hyalinizing peritoneal sclerosis (HPS), also known as simple sclerosis, is observed in almost all of PD patients. HPS is morphologically characterized by fibrosis of the submesothelial interstitium and hyalinizing vascular wall, particularly of the post-capillary venule (PCV). Two histological factors, the thickness of submesothelial compact zone (SMC) and the lumen/vessel ratio (L/V) at the PCV, have been used for the quantitative evaluation of HPS. The measuring system on SMC thickness and L/V ratio is easy and useful for evaluating the severity of HPS. On the other hand, EPS is characterized by unique encapsulation of the intestines by an "encapsulating membrane". This newly formed membranous structure covers the visceral peritoneum of the intestines, which contains fibrin deposition, angiogenesis, and proliferation of fibroblast-like cells and other inflammatory cells. This review will cover the common understandings of PD-related peritoneal alterations and provide a basic platform for clinical applications and future studies in this field.

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.

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.

Multiple abdominal cocoons: an unusual presentation of intestinal obstruction and a diagnostic dilemma

Sclerosing encapsulating peritonitis (SEP) or abdominal cocoon is a rare acquired condition with an unknown aetiology. It is characterized by encapsulation of the small bowel by a fibrous membrane and can lead to intestinal obstruction. We present the case of a 42-year-old gentleman with a history of hepatitis C, tuberculosis, and previous abdominal surgery, who presented with subacute intestinal obstruction. Surgical exploration of the abdomen revealed that the entire contents were enclosed into three distinct sacs by a dense fibrous membrane. Excision of the sacs was performed followed by adhesiolysis. This is believed to be the first reported case of multiple cocoons within the abdominal cavity. The case is discussed with reference to the literature.

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.

Discovering implicit associations in a case of encapsulating peritoneal sclerosis complicated by severe mineral imbalance

We describe the case of a 42-year-old woman who developed encapsulating peritoneal sclerosis (EPS) after 7 years on peritoneal dialysis, with clinical relief by enterolysis associated to treatment with tamoxifen, corticosteroids and parenteral nutrition in haemodialysis. During the next 7 months, she was also conservatively stabilised for mild hyperparathyroidism until she was admitted with calciphylaxis, associated with massive extraosseous calcification. Despite parathyroidectomy and sodium thiosulfate treatment, which resulted in a successful resolution of calciphylaxis, she died 1 year later due to a gross calcified peritoneum. In view of controlled hyperparathyroidism, the massive extraosseous calcification beginning after EPS diagnosis furthermore corroborates a recently suggested role for calcium-regulatory factors associated with poor outcome in EPS.

Effect of DNA demethylation in experimental encapsulating peritoneal sclerosis

Encapsulating peritoneal sclerosis (EPS) involves excessive peritoneal fibrosis in patients on peritoneal dialysis, eventually leading to visceral constriction and bowel obstruction. Few studies have investigated epigenetic mechanisms relating to EPS. Here we evaluated the therapeutic effects of DNA demethylation in experimental EPS. Experimental EPS was induced by intraperitoneal injection of 0.1% chlorhexidine gluconate (CG) and 15% ethanol in non-uremic male Sprague-Dawley (SD) rats. Rats were divided into three groups: group C (N=5) with saline injection only, group CG (N=7) with EPS induction for 4 weeks, and chlorhexidine gluconate and azacytidine (CGA) treated group (N=7) with EPS induction for 4 weeks and 5'-azacytidine injection for the last 2 weeks. Morphometric analysis of peritoneum and immunohistochemical staining for type 1 collagen and α-smooth muscle actin (α-SMA) were performed. Expressions of transforming growth factor-β (TGF-β), fibroblast-specific protein 1 (FSP1), and DNA methyltransferase 1 (DNMT1) were analyzed by Western blot. Methylation-specific polymerase chain reaction (PCR) for Ras GTPase activating-like protein 1 (RASAL1) was performed with measurement of RASAL1 protein expression. Parietal peritoneal thickness and the number of vessels in omental tissue were significantly decreased in group CGA compared to group CG, as were the expressions of type 1 collagen, α-SMA, TGF-β, and FSP1. DNMT1 was significantly increased in group CG, and reduced in group CGA. RASAL1 hypermethylation was associated with decreased RASAL1 protein expression in group CG, which was reversed in group CGA. DNA demethylation by 5'-azacytidine treatment improved pathologic changes of the peritoneum in experimental EPS, and was associated with reversal of increased DNMT1 expression and RASAL1 hypermethylation.

Multidisciplinary clinical strategies for encapsulating peritoneal sclerosis in peritoneal dialysis: update from Japan

Peritoneal dialysis is established as a first-line standard renal replacement therapy for end-stage renal disease. However, the development of encapsulating peritoneal sclerosis has been a critical complication among long-term peritoneal dialysis patients. During the past decade, multidisciplinary approaches have been used to suppress encapsulating peritoneal sclerosis. The present article reviews the historical and present status of encapsulating peritoneal sclerosis in Japan.

Can EPS development be avoided with early interventions? The potential role of tamoxifen--a single-center study

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is a severe complication of peritoneal dialysis (PD). Identification of patients at high risk for EPS ("EPS-prone") and delivery of appropriate interventions might prevent its development. Our aim was to evaluate the clinical characteristics and outcomes of all EPS and EPS-prone patients diagnosed at our PD unit.

METHODS

For a 30-year period representing our entire PD experience, we retrospectively identified all patients with EPS (diagnosed according to International Society for Peritoneal Dialysis criteria) and all patients defined as EPS-prone because they met at least 2 established criteria (severe peritonitis, PD vintage greater than 3 years, severe hemoperitoneum, overexposure to glucose, and acquired ultrafiltration failure).

RESULTS

Of 679 PD patients, we identified 20 with EPS, for an overall prevalence of 2.9%. Mean age at diagnosis was 50.2 ± 16.4 years, with a median PD time of 77.96 months (range: 44.36 - 102.7 months) and a median follow-up of 30.91 months (range: 4.6 - 68.75 months). Of patients with EPS, 10 (50%) received tamoxifen, 10 (50%) received parenteral nutrition, and 2 (10%) underwent adhesiolysis, with 25% mortality related to EPS. Another 14 patients were identified as EPS-prone. Median follow-up was 54.05 months (range: 11.9 - 87.04 months). All received tamoxifen, and 5 (36%) received corticosteroids; none progressed to full EPS. We observed no differences in baseline data between the groups, but the group with EPS had been on PD longer (84 ± 53 months vs 39 ± 20 months, p = 0.002) and had a higher cumulative number of days of peritoneal inflammation from peritonitis (17.2 ± 11.1 days vs 9.8 ± 7.9 days, p = 0.015). Overall mortality was similar in the groups. The incidence of EPS declined during our three decades of experience (5.6%, 3.9%, and 0.3%).

CONCLUSIONS

Being a serious, life-threatening complication of PD, EPS requires high suspicion to allow for prompt diagnosis and treatment. Early detection of EPS-prone states and delivery of appropriate intervention might prevent EPS development. Tamoxifen seems to be a key strategy in prevention, but caution should be used in interpreting our results. Additional randomized controlled studies are needed.

Encapsulating peritoneal sclerosis in the era of a multi-disciplinary approach based on biocompatible solutions: the NEXT-PD study

INTRODUCTION

Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis (PD). Over the past decade in Japan, a multidisciplinary approach has been adopted to minimize the incidence and improve outcomes of EPS. This strategy includes planned PD discontinuation for high-risk patients and the introduction of biocompatible solutions. This study examined the current clinical status of EPS in representative PD centers in Japan.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

Patients (n = 1,338) from 55 PD centers in Japan who were using neutral-pH solutions from the initiation of therapy (mean age, 62 years; median PD duration, 32 months; concomitant use of icodextrin, 35.2%; PD and hemodialysis combination therapy, 12.2%) were assessed every 6 months to ascertain the reasons for PD discontinuation and the development of EPS development. Outcomes were also recorded. The study period was from November 2008 to March 2012.

RESULTS

There were 727 patients who discontinued PD, including 163 deaths. Among all causes of PD withdrawal except for death, planned PD discontinuation to avoid EPS was utilized in 58 cases (7.1% in total). The strategy was increasingly utilized in proportion to the duration of PD: 0.5% for patients undergoing PD for < 3 years, 0.6% for patients undergoing PD for 5 years, 14.7% for patients undergoing PD for 8 years, and 35.5% for patients undergoing PD for > 8 years. Fourteen patients developed EPS (three cases after PD), which corresponded with an overall incidence of 1.0%. The incidence according to the duration of PD was 0.3% for PD < 3 years, 0.6% for PD = 5 years, 2.3% for PD = 8 years, and 1.2% for PD > 8 years. In terms of therapy, 11 patients were treated with prednisolone (PSL), and surgical enterolysis was utilized in two cases. Complete remission of abdominal symptoms was achieved in twelve patients (85.7%), and three died due to EPS (mortality rate of 21.4%).

CONCLUSIONS

Use of the multidisciplinary approach described above reduces the risk of the development of EPS according to PD duration. In cases of de novo EPS cases in Japan, this strategy can also attenuate the clinical course of the condition.

Mesenchymal Conversion of Mesothelial Cells Is a Key Event in the Pathophysiology of the Peritoneum during Peritoneal Dialysis

Peritoneal dialysis (PD) is a therapeutic option for the treatment of end-stage renal disease and is based on the use of the peritoneum as a semipermeable membrane for the exchange of toxic solutes and water. Long-term exposure of the peritoneal membrane to hyperosmotic PD fluids causes inflammation, loss of the mesothelial cells monolayer, fibrosis, vasculopathy, and angiogenesis, which may lead to peritoneal functional decline. Peritonitis may further exacerbate the injury of the peritoneal membrane. In parallel with these peritoneal alterations, mesothelial cells undergo an epithelial to mesenchymal transition (EMT), which has been associated with peritoneal deterioration. Factors contributing to the bioincompatibility of classical PD fluids include the high content of glucose/glucose degradation products (GDPs) and their acidic pH. New generation low-GDPs-neutral pH fluids have improved biocompatibility resulting in better preservation of the peritoneum. However, standard glucose-based fluids are still needed, as biocompatible solutions are expensive for many potential users. An alternative approach to preserve the peritoneal membrane, complementary to the efforts to improve fluid biocompatibility, is the use of pharmacological agents protecting the mesothelium. This paper provides a comprehensive review of recent advances that point to the EMT of mesothelial cells as a potential therapeutic target to preserve membrane function.

Encapsulating peritoneal sclerosis: case series from a university center

BACKGROUND/AIMS

Encapsulating peritoneal sclerosis (EPS) is an often-fatal complication of long-term peritoneal dialysis (PD). We here report the clinical features of EPS in Korean PD patients from a single university center.

METHODS

The data were collected retrospectively from 606 PD patients at Kyungpook National University Hospital, between August 2001 and August 2011. The diagnosis of EPS was based on clinical signs and symptoms, and confirmed by radiological findings.

RESULTS

Eight patients (1.3%, four males) were diagnosed with EPS. The mean age of the patients was 48.5 years (range, 33 to 65). The mean duration of PD was 111.8 months (range, 23 to 186). All patients except for one had three or more episodes of peritonitis. Seven patients were diagnosed with EPS after stopping PD, and only one stayed on PD after initial diagnosis and treatment. Total parenteral nutrition and corticosteroids, in addition to tamoxifen therapy, were used to treat most of the patients, and one patient underwent surgery (adhesiolysis). The overall mortality rate was 50%.

CONCLUSIONS

EPS is a serious, life-threatening complication in patients on long-term PD. To reduce the incidence and mortality rate of EPS, careful monitoring and early diagnosis is needed.

Persistent sterile peritoneal inflammation after catheter removal for refractory bacterial peritonitis predicts full-blown encapsulating peritoneal sclerosis

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is the most serious complication of peritoneal dialysis, having high morbidity and mortality. To improve outcomes, early diagnosis is needed to direct treatment during the early inflammatory phase. However, in the early inflammatory phase, clinical features are nonspecific, and no reliable diagnostic criteria have been established. Because bacterial peritonitis and termination of dialysis are two important risk factors triggering the progression of EPS, patients with refractory bacterial peritonitis necessitating dialysis catheter removal are at particularly high risk of developing EPS. Many of these patients might indeed experience non-resolving sterile peritonitis (probably the inflammatory phase of EPS) before progression to full-blown disease (that is, the presence of intestinal obstruction). We undertook a retrospective study to compare, in this particular situation, the clinical characteristics of patients with or without sterile peritoneal inflammation, assessing their clinical outcomes in terms of short-term mortality and the chance of developing full-blown EPS.

METHODS

Our retrospective review included 62 patients whose dialysis catheter was removed because of refractory peritonitis between January 2005 and December 2010.

RESULTS

Of the 62 patients identified, 39 (63%) had persistent sterile peritoneal inflammation ("high-risk" group, n = 39), and 23 (37%) had resolution of inflammation without significant intra-abdominal collection after catheter withdrawal ("control" group, n = 23). Compared with the control group, the high-risk group had a significantly longer PD duration (71.6 ± 43.3 months vs 42.3 ± 29.9 months, p = 0.003), a higher dialysate-to-plasma ratio (D/P) of creatinine (0.768 ± 0.141 vs 0.616 ± 0.091, p = 0.004), and a higher computed tomography score for EPS (7.69 ± 2.98 vs 1.00 ± 1.00, p < 0.001). During the 6-month study period, the high-risk group had a higher chance of developing full-blown EPS (31% vs 0%, p = 0.002) and a higher 6-month all-cause mortality (36% vs 4.3%, p = 0.004).

CONCLUSIONS

Persistent sterile peritoneal inflammation was common after dialysis catheter removal for refractory bacterial peritonitis, and the patients with such inflammation were at high risk of progression to full-blown EPS.

Phenotypes of encapsulating peritoneal sclerosis--macroscopic appearance, histologic findings, and outcome

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) is a rare but devastating complication of peritoneal dialysis (PD), with clinical signs of abdominal pain, bowel obstruction, and weight loss in late stages.

METHODS

We retrospectively analyzed all patients who were diagnosed with EPS between March 1998 and October 2011 in our department of nephrology. We focused on the 24 EPS patients who underwent surgery because of symptomatic late-stage EPS. We identified 3 different macroscopic phenotypes of EPS that we categorized as types I - III. We correlated histologic findings with those macroscopic phenotypes of EPS. The postoperative and long-term outcomes were evaluated by macroscopic phenotype.

RESULTS

Duration of PD was longer in type III than in types I and II EPS (p = 0.05). We observed no other statistically significant differences between the groups in baseline characteristics, except for operation time, which was longer in the type I than in the type III group (p = 0.02). Furthermore, we observed no statistically significant difference between the groups with respect to the onset of complaints before surgery (7.8 ± 5.9 months vs 7.0 ± 7.0 months vs 6.5 ± 5.3 months). Concerning patient outcomes, there was no evidence that any of the macroscopic EPS types was associated with more major or minor complications after surgery. For all study patients, follow-up was at least 3 years, with 19 patients still being alive, and 16 having no or very mild complaints. The typical histologic findings of EPS were present in all macroscopic types; only fibrin deposits were more prominent in type II than in type III.

CONCLUSIONS

We describe 3 subtypes of EPS based on macroscopic findings. Postoperative treatment should probably not be influenced by the macroscopic EPS phenotype. Whether the different phenotypes represent different pathophysiologic processes remains unclear and has to be further evaluated.

Lower mortality and inflammation from post-transplantation encapsulating peritoneal sclerosis compared to the classical form

BACKGROUND

Encapsulating peritoneal sclerosis (EPS) may occur after kidney transplantation (post-transplantation EPS) or may be diagnosed during or after peritoneal dialysis treatment (classical EPS). The aim of the present study was to investigate to what extent both EPS entities differ in clinical presentation, radiological findings, outcome, and the systemic inflammatory response, as measured by plasma C-reactive protein (CRP) levels both prior to and after EPS diagnosis.

METHODS

We performed a retrospective analysis of 15 post-transplantation EPS and 19 classical EPS patients who were diagnosed at seven hospitals in the Netherlands between January 1, 2000, and January 1, 2011.

RESULTS

There were no inter-group differences in age, duration of peritoneal dialysis, clinical presentation, or radiology findings at diagnosis. Post-transplantation patients had experienced a lower number of peritonitis episodes per patient-year (0.2 (0.0-0.4) vs. 0.7 (0.3-1.2), p = 0.01) with a longer interval between the last peritonitis and EPS diagnosis (18.1 (4.6-34.3) vs. 4.4 (0.89-13.78) months, p = 0.01). Post-transplantation EPS patients showed a remarkably lower mortality rate (40.0 vs. 84.2%, p < 0.05). In both groups a pattern of elevated CRP values was observed, increasing within the year before EPS diagnosis. In the post-transplantation group the median CRP level at diagnosis was lower (56.0 vs. 144.50 mg/l, p < 0.05) than in the classical EPS group.

CONCLUSION

Post-transplantation EPS has a similar clinical presentation as classical EPS but with a lower systemic inflammatory response and better outcome.