Sclerosing peritonitis: the experience in Australia

Pathophysiological Mechanisms of Peritoneal Fibrosis and Peritoneal Membrane Dysfunction in Peritoneal Dialysis

The characteristic feature of chronic peritoneal damage in peritoneal dialysis (PD) is a decline in ultrafiltration capacity associated with pathological fibrosis and angiogenesis. The pathogenesis of peritoneal fibrosis is attributed to bioincompatible factors of PD fluid and peritonitis. Uremia is associated with peritoneal membrane inflammation that affects fibrosis, neoangiogenesis, and baseline peritoneal membrane function. Net ultrafiltration volume is affected by capillary surface area, vasculopathy, peritoneal fibrosis, and lymphangiogenesis. Many inflammatory cytokines induce fibrogenic growth factors, with crosstalk between macrophages and fibroblasts. Transforming growth factor (TGF)-β and vascular endothelial growth factor (VEGF)-A are the key mediators of fibrosis and angiogenesis, respectively. Bioincompatible factors of PD fluid upregulate TGF-β expression by mesothelial cells that contributes to the development of fibrosis. Angiogenesis and lymphangiogenesis can progress during fibrosis via TGF-β-VEGF-A/C pathways. Complement activation occurs in fungal peritonitis and progresses insidiously during PD. Analyses of the human peritoneal membrane have clarified the mechanisms by which encapsulating peritoneal sclerosis develops. Different effects of dialysates on the peritoneal membrane were also recognized, particularly in terms of vascular damage. Understanding the pathophysiologies of the peritoneal membrane will lead to preservation of peritoneal membrane function and improvements in technical survival, mortality, and quality of life for PD patients.

Acute presentation of cocoon abdomen as intestinal obstruction mimicking with strangulated eventration: A case report

INTRODUCTION

Abdominal cocoon syndrome (ACS), or sclerosing encapsulating peritonitis (SEP) is a rare cause of intestinal obstruction in which the bowel and internal abdominal organs are wrapped with a fibrocollagenous cocoon-like encapsulating membrane. While cocooning of the abdomen primarily manifests in individuals undergoing peritoneal dialysis (PD), it has also been reported to occur spontaneously. Remarkably rare, SEP may present with complete mechanical bowel obstruction in select cases.

CASE PRESENTATION

We hereby report a case of an 87-year-old female patient with a prior history of abdominal surgery, who presented to our emergency department with a clinical picture of complete small bowel obstruction. Clinical and radiological data were suggestive of a strangulated midline hernia, prompting a therapeutic laparotomy. The surgical exploration revealed the encasement of the small bowel loops within a thick fibrocollagenous membrane. Efficient resolution was achieved through skillful adhesiolysis and the meticulous excision of the fibrocollagenous membrane.

DISCUSSION

SEP is more prevalent in men, with a higher incidence observed in tropical and subtropical countries. While the precise pathophysiology remains elusive, it is hypothesized that subclinical intraabdominal inflammation gives rise to the formation of a dense fibrocollagenous membrane. This membrane encapsulates intraperitoneal organs, ultimately leading to intestinal obstruction. Patients typically present with a recurrent history of small bowel obstruction, notably in the absence of prior abdominal surgery. Abdominal CT scan with experienced radiologist interpretation can aid in preoperative diagnosis. In cases where non-operative management fails and recurrent obstructions persist, surgical adhesiolysis stands as the well-established gold standard.

CONCLUSION

SEP is a rare abdominal disease, posing challenges for preoperative diagnosis. Laparotomy plays an important role in its diagnosis and treatment. The primary objective of the surgical intervention is to release the encapsulation of the bowel and safeguard the optimal functioning of the small intestines as much as possible.

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.

Imaging Patients with Kidney Failure

The approach to imaging a patient with kidney failure continues to evolve. Overstatement of the risk of iodinated contrast material-induced (ie, contrast-induced) acute kidney injury and new guidelines for administration of gadolinium-based contrast media affect screening and the choice of contrast material. Treatment of kidney failure requires dialysis or a kidney transplant. Pretransplant imaging includes assessment for the feasibility of performing a transplant and evaluation for underlying malignancy and peripheral vascular disease. Patients with kidney failure are at high risk for renal cell carcinoma. Subtypes that occur exclusively or more commonly in patients with kidney failure, such as acquired cystic kidney disease, renal cell carcinoma, and clear cell papillary renal cell carcinoma, have specific clinical-pathologic characteristics, with indolent behavior. Performing US for dialysis planning increases the success of placement of an arteriovenous fistula, while postoperative US evaluation is essential in assessment of access dysfunction. Systemic manifestations in patients with kidney failure are multifactorial and may relate to the underlying cause of renal failure or may be secondary to treatment effects. Disturbances in mineral and bone metabolism and soft-tissue and vascular calcifications are seen in patients with chronic kidney disease and mineral bone disorder. Neurologic and cardiothoracic complications are also common. The authors provide a comprehensive overview of imaging considerations for patients with kidney failure, including the appropriate use of CT, MRI, and US with their respective contrast agents; the use of imaging in transplant workup and dialysis assessment; and the common renal and extrarenal manifestations of kidney failure. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

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.

A Rare Case of Extensive Eggshell Intestinal Wall Peritoneal Calcification in a Long-Term Continuous Peritoneal Dialysis Patient

Encapsulating peritoneal sclerosis (EPS) is a rare but rather serious complication of long-term peritoneal dialysis. The etiology of EPS is multifactorial, with long-term peritoneal dialysis, multiple peritonitis episodes, and uncontrolled hyperparathyroidism considered to be major risk factors for this often life-threatening condition. We report a case of a 55-year-old female patient with Down syndrome and end-stage renal disease (ESRD) on long-term peritoneal dialysis (PD) with extensive intestinal peritoneal calcifications and a rather uncomplicated long follow-up.

Calcified encapsulating peritoneal sclerosis associated with peritoneal dialysis: A case report

Encapsulating peritoneal sclerosis (EPS) is a rare, but sometimes fatal, complication of peritoneal dialysis characterized by diffuse thickening and encapsulation of the bowel and peritoneum. In more advanced cases, the peritoneum will gradually calcify. EPS usually presents as partial small bowel obstruction and diagnosed on imaging studies. We present a case of a 19-year-old female on long-term peritoneal dialysis with EPS and diffuse peritoneal calcifications.

Use of paclitaxel carried in solid lipid nanoparticles to prevent peritoneal fibrosis in rats

Background

Progressive fibrous thickening of peritoneal membrane (PM) is a major complication of long-term peritoneal dialysis. TGF-β/SMAD pathway activation, inflammation and neoangiogenesis have an important role in PM changes induced by peritoneal dialysis. Here, we investigated the effects of paclitaxel (PTX) carried in lipid core nanoparticles (LDE) on the development of peritoneal fibrosis (PF) in rats.

Methods

To induce PF, 21 male Wistar rats (300-350g) were injected with chlorhexidine gluconate for 15 consecutive days and randomly assigned to three groups: 1)PF, n = 5: no treatment; 2)LDE, n = 8: treated with LDE only, 3/3 days during 15 days; 3)LDE-PTX, n = 8: treated with PTX (4mg/kg) associated with LDE, 3/3 days during 15 days. A Control group without PF induction (n = 5) was designed, received saline solution, 3/3 days. Peritoneum function tests were performed, and anterior abdominal wall samples of the PM were collected for analyses of peritoneal thickness, immunohistochemitry, and gene expression.

Results

LDE-PTX treatment preserved the membrane function, maintaining the ultrafiltration rate and mass transfer of glucose at normal levels. LDE-PTX also prevented PM thickening induced by chlorhexidine gluconate injections. LDE-PTX treatment reduced the number of myofibroblasts infiltrating PM and inhibited the cell proliferation. Gene expression of fibronectin, FSP-1, VEGF, TGF-β, and SMAD3 were reduced by LDE-PTX.

Conclusions

LDE-PTX was effective to prevent development of PF and preserve the PM filtration capacity in this rat model, with clear-cut actions on pro-fibrotic mechanisms. Thus, LDE-PTX can be candidate for future clinical trials as adjuvant to peritoneal dialysis to prevent PF development, since this preparation is devoid of toxicity as shown previously.

Surgical timing for primary encapsulating peritoneal sclerosis: A case report and review of literature

BACKGROUND

Primary encapsulating peritoneal sclerosis (EPS) is a rare but devastating disease that causes fibrocollagenous cocoon-like encapsulation of the bowel, resulting in bowel obstruction. The pathogenesis, prevention, and treatment strategies of EPS remain unclear so far. Since most patients are diagnosed during exploratory laparotomy, for the non-surgically diagnosed patients with primary EPS, the surgical timing is also uncertain.

CASE SUMMARY

A 44-year-old female patient was referred to our center on September 6, 2021, with complaints of abdominal distention and bilious vomiting for 2 d. Physical examination revealed that the vital signs were stable, and the abdomen was slightly distended. Computerized tomography scan showed a conglomerate of multiple intestinal loops encapsulated in a thick sac-like membrane, which was surrounded by abdominal ascites. The patient was diagnosed with idiopathic EPS. Recovery was observed after abdominal paracentesis, and the patient was discharged on September 13 after the resumption of a normal diet. This case raised a question: When should an exploratory laparotomy be performed on patients who are non-surgically diagnosed with EPS. As a result, we conducted a review of the literature on the clinical manifestations, intraoperative findings, surgical methods, and therapeutic effects of EPS.

CONCLUSION

Recurrent intestinal obstructions and abdominal mass combined with the imaging of encapsulated bowel are helpful in diagnosing idiopathic EPS. Small intestinal resection should be avoided.

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.

Diabetes Is the Most Critical Risk Factor of Adverse Complications After Peritoneal Dialysis Catheter Placement

Introduction: Peritoneal dialysis (PD) is a kind of renal replacement therapy for end-stage renal disease (ESRD). While PD has many advantages, various complications may arise.

Methods: This retrospective study analyzed the complications of ESRD patients who received PD catheter implantation in a single medical center within 15 years.

Results: This study collected 707 patients. In the first 14 days after PD implantation, 54 patients experienced bleeding complications, while 47 patients experienced wound infection. Among all complications, catheter-related infections were the most common complication 14 days after PD implantation (incidence: 38.8%). A total of 323 patients experienced PD catheter removal, of which 162 patients were due to infection, while 96 were intentional due to kidney transplantation. Excluding those whose catheters were removed due to transplantation, the median survival of the PD catheter was 4.1 years; among them, patients without diabetes mellitus (DM) were 7.4 years and patients with DM were 2.5 years (p < 0.001). Further, 50% probability of surviving was beyond 3.5 years in DM patients with HbA1CC < 7 and 1.6 years in DM patients with HbA1C <7 (p ≥ 0.001).

Conclusions: Catheter-related infections were the most common complications following PD catheter implantation. DM, especially with HbA1C ≥7, significantly impacted on the catheter-related infection and the survival probability of the PD catheter.

Abdominal cocoon in children: A case report and review of literature

BACKGROUND

Abdominal cocoon or “encapsulating peritoneal sclerosis” (EPS) is an uncommon and rare cause of intestinal obstruction. Only a few cases have been reported in paediatric patients. Typically, EPS is described as the primary form in young adolescent girls from tropical and subtropical countries because of viral peritonitis due to retrograde menstruation or a history of peritoneal dialysis. Most patients are asymptomatic or present with abdominal pain, which is likely to occur secondary to subacute bowel obstruction. Findings at imaging, such as ultrasound, computed tomography, and magnetic resonance imaging, are often nonspecific. When diagnosed, EPS is characterized by total or partial encasement of the bowel within a thick fibrocollagenous membrane that envelopes the small intestine in the form of a cocoon because of chronic intraabdominal fibroinflammatory processes. The membrane forms a fibrous tissue sheet that covers, fixes, and finely constricts the gut, compromising its motility.

CASE SUMMARY

We present a case of EPS in a 12-year-old boy 8 wk after primary surgery for resection of symptomatic jejunal angiodysplasia. There was no history of peritoneal dialysis or drug intake.

CONCLUSION

In this report, we sought to highlight the diagnostic, surgical, and histopathological characteristics and review the current literature on EPS in paediatric patients.

Assessment of peritoneal thickness using CT in relation to dialysis adequacy in peritoneal dialysis patients

Studies assessing peritoneal thickness by CT in peritoneal dialysis (PD) patients are lacking. In this study, we aimed to investigate the association between peritoneal thickness as measured by CT and dialysis adequacy with peritoneal membrane characteristics in PD patients. Ninety-four PD patients were enrolled. Peritoneal thickness was measured by CT. Patients with and without a decrease in Kt/V of at least 0.3 over time were classified as Group 1 and Group 2, respectively. An increase of 0.1 unit of dialysate/plasma (D/P) creatinine over time were considered significant. The relationship between peritoneal membrane thickness, change in Kt/V, and peritoneal membrane characteristics were investigated. There were 31 (33.0%) patients in Group 1. The duration of PD (86.0 ± 64.1 vs. 59.6 ± 45.2 months, p: 0.023), peritoneal thickness (1.02 ± 0.37 vs. 0.87 ± 0.21 mm, p: 0.015), peritoneal calcification (7 [22.6%] vs. 3 [4.8%] patients, p: 0.013], increased D/P creatinine ratio (14 [45.2%] vs. 14 [22.2%] patients, p: 0.031) and CRP (13.9 ± 11.2 vs. 7.1 ± 4.8 mg/L, p: 0.045) were significantly higher in Group 1, whereas albumin (3.6 ± 0.5 vs. 3.8 ± 0.6 g/dL, p: 0.047) and parathyroid hormone (355.2 ± 260.2 vs. 532.1 ± 332.9 ng/L, p: 0.015) levels were significantly lower. Peritoneal thickness was significantly correlated with duration of PD (r: 0.775, p < 0.001) and CRP (r: 0.282, p: 0.006). Regression analysis showed that peritoneal thickness (Exp (B) [95% CI]: 0.029 [0.003-0.253], p: 0.001) was independent predictor of decreased Kt/V in PD patients. In conclusion, prolonged PD duration and increased peritoneal thickness are associated with a decrease in Kt/V over time. CT may be an alternative and noninvasive method instead of peritoneal biopsy for determining the structural changes of the peritoneal membrane .

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.

Non-infectious complications of peritoneal dialysis and peritoneal scintigraphy

Peritoneal dialysis (PD) is an alternative to hemodialysis that is indicated in patients with chronic end-stage disease. It has many advantages, but also complications such as dialysate leaks around the catheter insertion site, in the abdominal wall or in the pleural cavity, inguinoscrotal hernia and even intra-abdominal fluid collection. Peritoneal scintigraphy is a simple, non-invasive, low-irradiation examination, without the risk of allergy, that allows both diagnosing and locating these complications because it allows acquiring images at the time of infusion, as well as remotely and after drainage of the dialysate. Tomoscintigraphy coupled with scanner SPECT / CT (Single Photon Emission Computed Tomography / Computed Tomography) can also help narrow the diagnosis. The objective of this article is to clarify the value of peritoneal scintigraphy in the diagnosis of non-infectious complications of peritoneal dialysis, the conditions for performing the examination and the potential indications, as illustrated by a few cases.

A case of cyclic hemoperitoneum in a hemodialysis patient: Encapsulated peritoneal sclerosis complicated by endometriosis and fungal peritonitis

Encapsulated peritoneal sclerosis (EPS) is a rare, but frequently fatal, long-term complication of peritoneal dialysis. Endometriosis is a common gynecological problem but hemoperitoneum due to endometriosis has been reported to be extremely rare in hemodialysis (HD) patients. A 25-year-old female HD patient was admitted to our clinic with nausea, vomiting, abdominal pain, and weight loss for last 3 months. Candida tropicalis and Candida glabrata were isolated in the fungal cultures from peritoneal fluid. Her abdominal computerized tomography scan has shown irregular peritoneal calcifications, diffuse peritoneal thickening, dilatation of the small bowel loops, and cocoon formation which all were typical for EPS. Hemoperitoneum was reported to recur for four times with intervals suggesting menstrual cycles. Her peritoneal biopsy, along with the signs of EPS, has also revealed the presence of endometriosis. The patient died with symptoms of septic shock in the first year of EPS diagnosis.

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.

Recommendation of the Surgical Option for Treatment of Encapsulating Peritoneal Sclerosis

Encapsulating peritoneal sclerosis (EPS) is an intestinal obstruction syndrome in which peritoneal deterioration and intraperitoneal inflammation result in intestinal adhesions, which are covered with a fibrin capsule and cause bowel obstruction. The widespread use of peritoneal dialysis (PD) has been associated with an increase in the number of patients with this life-threatening complication. For this reason, some negative comments have been made about PD therapy. However, recent clinical studies have elucidated the pathogenesis of EPS and proposed therapeutic strategies.

Currently, these facts are known: • EPS occurs in 2.5% of all patients (3.18/1000 patient-years). • A longer duration of PD is associated with a higher incidence of EPS and a poorer prognosis, indicating the involvement of peritoneal deterioration in the development of EPS. • Development of EPS involves some kind of infection. • Development of EPS frequently occurs after PD withdrawal and catheter removal. • Peritoneal lavage after PD withdrawal delays, but cannot prevent the development of EPS. • Timely administration of steroids is effective. • Surgical adhesiolysis is the optimal treatment to relieve bowel obstructions, but does not exclude the potential for re-adhesions, requiring various ingenious gastrointestinal surgical techniques.

Encapsulating Peritoneal Sclerosis: Prevention and Treatment

Since the first peritoneal dialysis (PD) patients with encapsulating peritoneal sclerosis (EPS) were reported in 1980, EPS has been considered primarily a fatal complication. The incidence of EPS in PD patients has been reported to be 2.5%, with a negative effect of increasing PD duration (which also augments mortality). Because EPS occurs after withdrawal from PD in more than half of all cases, strict monitoring is necessary when a long-term PD patient is withdrawn from PD. Maintaining patients on standard PD with conventional solutions for more than 8 years is associated with a substantial risk of EPS development. Treatment appropriate to the disease stage is most important in EPS. Basic therapeutic strategies for EPS include the appropriate use of steroids. If bowel obstruction persists, laparotomy and enterolysis should be performed to achieve a complete cure. It is now recognized that EPS need not be a fatal complication of PD.

Trehalose ameliorates peritoneal fibrosis by promoting Snail degradation and inhibiting mesothelial-to-mesenchymal transition in mesothelial cells

Peritoneal fibrosis (PF) is a severe complication of peritoneal dialysis, but there are few effective therapies for it. Recent studies have revealed a new biological function of trehalose as an autophagy inducer. Thus far, there are few reports regarding the therapeutic effects of trehalose on fibrotic diseases. Therefore, we examined whether trehalose has anti-fibrotic effects on PF. PF was induced by intraperitoneal injection of chlorhexidine gluconate (CG). CG challenges induced the increase of peritoneal thickness, ColIα₁ mRNA expression and hydroxyproline content, all of which were significantly attenuated by trehalose. In addition, CG challenges induced a marked peritoneal accumulation of α-SMA⁺ myofibroblasts that was reduced by trehalose. The number of Wt1⁺ α-SMA⁺ cells in the peritoneum increased following CG challenges, suggesting that a part of α-SMA⁺ myofibroblasts were derived from peritoneal mesothelial cells (PMCs). The number of Wt1⁺ α-SMA⁺ cells was also suppressed by trehalose. Additionally, trehalose attenuated the increase of α-SMA and ColIα₁ mRNA expression induced by TGF-β₁ through Snail protein degradation, which was dependent on autophagy in PMCs. These results suggest that trehalose might be a novel therapeutic agent for PF through the induction of autophagy and the suppression of mesothelial-to-mesenchymal transition in PMCs.

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.

Vasculopathy plays an important role during the development and relapse of encapsulating peritoneal sclerosis with conventional peritoneal dialysis solutions

Background

Encapsulating peritoneal sclerosis (EPS) is an uncommon but life-threatening complication of peritoneal dialysis (PD) therapy. The causative factors of EPS remain unclear. Pathological studies of the peritoneum affected by EPS and relationships with clinical factors including PD solutions remain lacking. The objective of this study was to examine peritoneal samples from EPS patients and to identify the associations of peritoneal pathology with different clinical factors.

Methods

Peritoneal specimens were obtained at the time of surgical enterolysis in Tsuchiya General Hospital from 1993 to 2016. A total of 223 PD patients were enrolled and analyzed. Tissues were fixed with formalin and processed with hematoxylin and eosin and Masson’s trichrome staining, as well as immunohistochemical staining for CD31 and CD68.

Results

Evaluations could be made in 174 patients who received surgical enterolysis. Conventional or pH-neutral low-glucose degradation product PD solutions were utilized during PD treatment. The conventional PD solution group showed less angiogenesis (P = 0.013) but more severe vasculopathy, in the form of a lower ratio of luminal diameter to vessel diameter (L/V ratio) (P &lt; 0.001) in association with longer PD treatment. Multivariate Cox proportional hazard models revealed that L/V ratio (per 0.1 increase, hazard ratio = 0.88, 95% confidence interval 0.77–0.99, P = 0.047) was significantly associated with a lower incidence of EPS relapse. In contrast, most of the cases in the pH-neutral solution group showed milder vasculopathy.

Conclusions

The pathology of EPS differed between conventional and pH-neutral solution groups. Vasculopathy was related to the development and relapse of EPS in the conventional solution group.

Estimating risk of encapsulating peritoneal sclerosis accounting for the competing risk of death

Background

Risk of encapsulating peritoneal sclerosis (EPS) is strongly associated with the duration of peritoneal dialysis (PD), such that patients who have been on PD for some time may consider elective transfer to haemodialysis to mitigate the risk of EPS. There is a need to determine this risk to better inform clinical decision making, but previous studies have not allowed for the competing risk of death.

Methods

This study included new adult PD patients in Australia and New Zealand (ANZ; 1990–2010) or Scotland (2000–08) followed until 2012. Age, time on PD, primary renal disease, gender, data set and diabetic status were evaluated as predictors at the start of PD, then at 3 and 5 years after starting PD using flexible parametric competing risks models.

Results

In 17 396 patients (16 162 ANZ, 1234 Scotland), EPS was observed in 99 (0.57%) patients, less frequently in ANZ patients (n = 65; 0.4%) than in Scottish patients (n = 34; 2.8%). The estimated risk of EPS was much lower when the competing risk of death was taken into account (1 Kaplan–Meier = 0.0126, cumulative incidence function = 0.0054). Strong predictors of EPS included age, primary renal disease and time on PD. The risk of EPS was reasonably discriminated at the start of PD (C-statistic = 0.74–0.79) and this improved at 3 and 5 years after starting PD (C-statistic = 0.81–0.92).

Conclusions

EPS risk estimates are lower when calculated using competing risk of death analyses. A patient’s estimated risk of EPS is country-specific and can be predicted using age, primary renal disease and duration of PD.

Vascular and Interstitial Changes in the Peritoneum of Capd Patients with Peritoneal Sclerosis

Objective

To analyze morphological changes in the peritoneum of peritoneal sclerosis (PS) patients. Emphasis was put on vascular abnormalities, because the continuous exposure to glucose-based dialysis solutions could cause diabetiform changes and because longitudinal transport studies suggested the development of a large peritoneal vascular surface area.

Design

Peritoneal biopsies from continuous ambulatory peritoneal dialysis (CAPD) patients were investigated in two studies. Diabetic patients were excluded. In study 1, 11 PS biopsies were compared to three control groups varying in duration of CAPD treatment: 0 months ( n = 15), 2 – 25 months ( n = 7), and > 25 months CAPD ( n = 7). The second study was a case-control study, comparing six biopsies from the long-term control group to six PS biopsies, matched for age and duration of CAPD. All biopsies were scored for presence and type of fibrosis [Picro Sirius red, type IV collagen, α-smooth muscle actin (αSMA)] and for neoangiogenesis (factor VIII). Thickening of vascular walls by type IV collagen and vasodilation of capillaries were measured by computer-aided planimetry.

Results

In study 1 the presence of sclerosing fibrosis, deposition of interstitial type IV collagen, and the number of myofibroblasts (αSMA-positive cells) was greater in the PS biopsies than biopsies from all control groups ( p < 0.002). Moreover, the number of vessels per field was higher in PS biopsies ( p < 0.01). Vascular wall thickening of small arteries ( p < 0.008) and vasodilation of capillaries were found in PS biopsies compared to all control groups ( p < 0.007). The second study revealed differences in the presence of sclerosis but not in the extent of fibrosis between PS biopsies and their controls. The number of vessels per field in PS biopsies was higher compared to controls ( p = 0.04). Also, thickening of the vascular wall was more marked in PS biopsies ( p = 0.03). Vasodilation of capillaries was greater in PS biopsies than in controls ( p = 0.07).

Conclusion

Fibrosis of the peritoneum may precede peritoneal sclerosis. The deposition of type IV collagen and the presence of myofibroblasts in the interstitial layer could be part of a pathologic process similar to the scarring in diabetic nephropathy. Neoangiogenesis and thickening of the vascular wall by type IV collagen are consistent with glucose-induced microangiopathy. These abnormalities and the vasodilation of the capillaries can explain the high dialysate-to-plasma ratios or mass transfer area coefficients of low molecular weight solutes that can be found in long-term CAPD patients.

Risk Factors for Poor Outcome of Fungal Peritonitis in Chinese Patients on Continuous Ambulatory Peritoneal Dialysis

Objective

Fungal peritonitis is rare among end-stage renal disease patients treated with continuous ambulatory peritoneal dialysis (CAPD), but when it occurs, it is associated with a high risk of mortality and peritoneal membrane failure. In the present study, we identified risk factors for poor outcome and examined the effect of treatment profile on outcome in fungal peritonitis.

Patients and Methods

We identified cases of fungal peritonitis in CAPD patients in a regional dialysis center and analyzed the possible risk factors for poor outcome in fungal peritonitis. To estimate the amount of dextrose presented to the peritoneum, we scored the dextrose content of the peritoneal dialysis fluid used by the patient at the time of admission to hospital (1 point to each bag of 1.5% fluid, 2 points to each bag of 2.3% or 2.5% fluid, and 3 points to each bag of 4.25% fluid daily).

Results

Among 471 episodes of CAPD-related peritonitis in 7.8 years, we identified 22 episodes of fungal peritonitis (4.7%). The ratio of men to women in the fungal peritonitis group was 1.4:1. Seventeen patients (77.3%) practiced dialysis without a helper. Within the 3 months preceding the fungal peritonitis, 12 patients (55%) had had bacterial peritonitis. Among the cases of fungal peritonitis, we identified 9 cases of Candida parapsilosis and 13 cases of non C. parapsilosis. All of the patients received fluconazole, and 7 patients (31.8%) also received flucytosine. The Tenckhoff catheter was removed in 17 patients (77.3%). Eight patients (36.4%) either died or lost peritoneal function. The risk of mortality was increased if the fungal organism was C. parapsilosis [odds ratio (OR): 4.25; 95% confidence interval (CI): 1.8 to 10.0; p = 0.002], if a helper was involved (OR: 11.3; 95% CI: 1.1 to 114; p = 0.024), or if CAPD duration was more than 26 months (OR: 2.2; 95% CI: 1.3 to 3.5; p = 0.034). Addition of flucytosine to fluconazole did not significantly improve the mortality rate in either the C. parapsilosis or non C. parapsilosis group. Multivariate analysis showed that C. parapsilosis was an independent factor associated with mortality ( p = 0.013). A dextrose score greater than 5 was associated with a trend toward increased risk of peritoneal failure (OR: 3.4; 95% CI: 1.6 to 7.1; p = 0.021).

Conclusion

C. parapsilosis is an independent risk factor for mortality in fungal peritonitis.

Peritoneal Dialysis in Japan: The Issue of Encapsulating Peritoneal Sclerosis and Future Challenges

Encapsulating peritoneal sclerosis (EPS) is a life-threatening complication of peritoneal dialysis (PD). The overall prevalence of EPS in Japanese PD patients is 2.3%. Among patients on PD for less than 5 years, the rate is 0.9%; among patients on PD for 5 – 10 years, the rate is 3.8%; and among patients on PD for >10 years, it is 11.5%. Thus, the longer the treatment duration, the higher the prevalence of EPS.

Encapsulating peritoneal sclerosis does not result solely from the natural progression of peritoneal sclerosis. A “second hit” event, such as bacterial peritonitis, abdominal bleeding, or abdominal surgery may be needed to trigger the onset of EPS in the face of advanced peritoneal sclerosis.

To prevent development of EPS, PD treatment is replaced by other treatments when patients reached high-transport status. Peritoneal lavage and prednisolone administration have been reported to be effective in preventing or stopping the progress of EPS. When bowel obstruction has occurred, total enterolysis to remove the fibrous capsule from the bowel is indicated.

To maximize overall quality of life, patients with end-stage renal disease (ESRD) should have the choice to make use of all the treatment modalities available: PD, hemodialysis (HD), and transplantation. Furthermore, the development of truly biocompatible PD equipment—including peritoneal catheters, solutions, and systems—are desirable to extend PD treatment for the long term. The cost of individual products could decrease significantly if PD use were to increase to 30% from 10% among ESRD patients worldwide. As practitioners, we have to further improve the technical survival rate and functional duration of PD treatment so that adequate peritoneal function can be maintained for 10 years in at least 40% of PD patients. The goal is to place PD on par with HD using high-flux dialysis membranes and ultrapure dialysis solution.

The Plasma Leak–to–Response Hypothesis: A Working Hypothesis on the Pathogenesis of Encapsulating Peritoneal Sclerosis after Long-Term Peritoneal Dialysis Treatment

Encapsulating peritoneal sclerosis (EPS) is one of the most serious complications of long-term peritoneal dialysis (PD). Long-term PD therapy has been suggested as a risk factor for EPS development among patients in Japan and Australia. Although the primary mechanism of EPS development has not been clarified, histologic changes of the peritoneum associated with prolonged PD are postulated to be causally related. The present article proposes a working hypothesis—the plasma leak–to–response hypothesis—that vascular alterations in the peritoneum of long-term PD patients play a crucial role in the initiation and development of EPS.

Sclerosing Peritonitis and Systemic Lupus Erythematosus: A Report of Two Cases

Objective

To heighten the awareness of a possible association of sclerosing peritonitis in patients with systemic lupus erythematosus (SLE).

Methods and Results

Over the course of 17 years (from January 1981 to December 1997), 371 patients were treated with continuous ambulatory peritoneal dialysis (CAPD) at Rush–Presbyterian–St Lukes Medical Center. The patients were followed on CAPD for an average of 25 ± 21 (SD) months with a median of 19 months (range 0.2 – 115 months). During this time only 2 (0.5%) patients were diagnosed with sclerosing peritonitis, and both had SLE with ongoing evidence of active disease while on CAPD. With a total of 26 SLE patients being treated with CAPD during the observation period, the prevalence of sclerosing peritonitis can be said to be as high as 8% in this patient population.

Conclusion

These cases suggest that autoimmune diseases, such as SLE, that are well known to cause immune-mediated serositis may represent an additional factor predisposing to the development of sclerosing peritonitis in patients treated with CAPD.

Recommendations on the Management of Encapsulating Peritoneal Sclerosis in Japan, 2005: Diagnosis, Predictive Markers, Treatment, and Preventive Measures

This comprehensive update on the management of encapsulating peritoneal sclerosis incorporates insights gained from recently published findings and the accumulated experience of the authors. Aspects covered include diagnosis, risk factors and predictive markers, treatment, and prevention, including criteria for withdrawal from peritoneal dialysis.

Epidemiology of Encapsulating Peritoneal Sclerosis in Japan

Since the first peritoneal dialysis (PD) patients with encapsulating peritoneal sclerosis (EPS) were reported in 1980, EPS has been considered primarily a fatal complication. The incidence of EPS in PD patients has been reported to range from 0.7% to 7.3%, and the rate appears to be higher in patients receiving long-term treatment. The most recent data from Japan show an overall incidence of 2.5%, with a clear impact of extended PD duration, which also augments mortality. The incidence increases and the prognosis worsens with longer durations of PD. The incidences (and mortality rates) for EPS were 0% (0%), 0.7% (0%), 2.1% (8.3%), 5.9% (28.6%), 5.8% (61.5%), and 17.2% (100%) for patients who had undergone PD for 3, 5, 8, 10, 15, and >15 years respectively. Because EPS occurs after withdrawal from PD in more than half of patients with the condition, strict monitoring is necessary when a long-term patient is withdrawn from PD. Maintaining patients on standard PD for more than 8 years using conventional solutions is associated with a substantial risk for the development of EPS.

Encapsulating Peritoneal Sclerosis in Japan: Prospective Multicenter Controlled Study

♦ Objective

Encapsulating peritoneal sclerosis (EPS) is recognized as a serious complication of peritoneal dialysis. The aim of this study was to determine the incidence, clinical features, and variation in mortality rates for EPS.

♦ Design

A prospective multicenter design was used, in which peritoneal dialysis patients were pre-registered by facilities across Japan and the incidence of EPS was observed in the registrants. The registrants were followed for a total of 4 years to accurately observe the onset of EPS.

♦ Results

As of April 1999, 2216 peritoneal dialysis patients from 64 facilities were registered. By the end of March 2001, 332 patients had dropped out, and 17 of the dropouts had developed SEP. The incidence was 0.77%. After excluding 110 patients who died, the incidence in 2106 patients was 0.81%. The incidence of EPS increased with the duration of peritoneal dialysis. Of the 17 patients with EPS, 12 developed the condition after discontinuing peritoneal dialysis and changing to hemodialysis. During the 2-year survey period, 6 of the 17 EPS patients died. The interval from onset to death was 10.8 ± 5.8 months (range: 3 – 19.5 months).

♦ Conclusions

From this prospective multicenter study, the current incidence of EPS is 0.77% (0.81% when dropout owing to death is censored). After a follow-up of 2 years, we conjecture that the incidence of EPS will increase. The incidence, etiology, and prognosis of EPS will be further clarified by periodic observation of dropouts until the end of March 2003.

Encapsulating Peritoneal Sclerosis—A Clinician's Approach to Diagnosis and Medical Treatment

Encapsulating peritoneal sclerosis (EPS) is recognized as a serious complication of continuous peritoneal dialysis. A preliminary diagnosis of EPS is usually based on clinical signs and symptoms, which commonly include abdominal pain, nausea, vomiting, anorexia, abdominal fullness, an abdominal mass, bowel obstruction, and radiologic findings, including abdominal roentgenogram, contrast studies, ultrasound studies, and computed tomography. The diagnosis is confirmed by laparoscopy or laparotomy showing the characteristic gross thickening of the peritoneum enclosing some or all of the small intestine in a cocoon of opaque tissue.

A variety of therapeutic approaches to EPS have been reported. This review discusses medical treatment of EPS and includes an overview of the clinical features and diagnostic aspects of the condition.

Successful Surgical Management of Encapsulating Peritoneal Sclerosis

♦ Background

Encapsulating peritoneal sclerosis (EPS) is a serious complication of long-term peritoneal dialysis (PD). The mortality rate for EPS has been high, primarily because of complications related to bowel obstruction. Also, therapeutic guidelines for EPS have not yet been established. In our hospital, favorable postoperative results were obtained in 50 patients whose EPS was treated surgically.

♦ Patients

All patients had chronic glomerulonephritis as the underlying kidney disease. All had undergone PD for between 29 months and 220 months (average: 113.9 months). During the course of PD, 3 patients developed EPS and were subsequently transferred to hemodialysis (HD). The other 47 patients (94.0%) developed EPS after discontinuation of PD. The reasons for transfer to HD were inadequate ultrafiltration (26 patients), bacterial peritonitis (16 patients), hypoalbuminemia (2 patients), renal transplantation (3 patients), and occurrence of EPS (3 patients).

♦ Intervention

At laparotomy, a definitive diagnosis of EPS was established in all patients by the presence of clumped intestine cocooned with a dense sclerotic membrane. In all cases, the small intestine was completely released by ablation of the capsules, resulting in resolution of the bowel obstruction symptoms. In 5 patients, the large intestine was ablated solely at the region of the sigmoid colon. The operating time varied from 3 hours to 18 hours (average: 6.9 hours). Oral food intake was initiated 5 – 60 days (average: 10.2 days) after surgery.

♦ Results

Perforation of the small intestine was detected postoperatively in 2 patients, who died 26 days and 37 days after surgery. The remaining 48 patients were followed for between 9 months and 107 months (average: 34.6 months). During follow-up, 6 – 12 months after the initial surgery, 4 patients experienced a recurrence of bowel obstruction symptoms that required a second laparotomy with enterolysis. Excluding the 2 patients with fatal outcomes, 46 patients (96%) experienced complete relief from bowel obstruction symptoms. The remaining 2 patients continued to experience mild, sub-acute bowel obstruction symptoms that could be successfully controlled solely by diet.

♦ Conclusions

Surgical treatment of 50 patients with EPS produced successful outcomes in all but 2 patients (96% success). Encapsulating peritoneal sclerosis should be actively treated by surgeons who genuinely understand this pathologic condition.

Changes in Peritoneal Coagulation and Fibrinolysis after Discontinuation of Chronic Peritoneal Dialysis

♦ Objectives

To study changes in peritoneal function after transfer from chronic peritoneal dialysis (CPD) to hemodialysis (HD), especially the effects on peritoneal coagulation, fibrinolytic markers, and mesothelium.

♦ Design

Prospective observational study.

♦ Setting

A tertiary-care university hospital.

♦ Patients

Nine patients who transferred from CPD to HD were enrolled in the study after giving fully informed consent.

♦ Methods

After transfer to HD, the peritoneal cavity was lavaged with low glucose PD solution once per day through PD catheters left in place. Thrombin–antithrombin III complex (TAT) was measured serially as a marker of peritoneal coagulation. As fibrinolytic markers, fibrinogen/fibrin degradation products (FDP) and plasmin–α2-antiplasmin complex (PIC) were assessed. Cancer antigen 125 (CA125) was measured as a marker of mesothelial cell mass.

♦ Results

Levels of peritoneal TAT and FDP were much higher than plasma levels, indicating high local fibrin turnover. Transfer to HD induced a significant fall in mean peritoneal TAT, from 115.8 ± 52.1 to 60.7 ± 21.8 ng/mL, p < 0.05. Except for 1 patient with a 20-fold increase, mean peritoneal FDP decreased significantly, from 43.6 ± 11.1 to 19.6 ± 3.5 μg/mL, p < 0.05. Mean peritoneal PIC increased significantly, from 1.9 ± 0.4 to 3.9 ± 0.6 μg/mL, p < 0.05. Peritoneal CA125 increased from 156.4 ± 57.3 to 1426.2 ± 389.4 U/mL, p < 0.05.

♦ Conclusions

Peritoneal fibrin turnover was accelerated on CPD and stabilized after transfer to HD. Transfer to HD also induced mesothelial regeneration.

Experimental Animal Models of Encapsulating Peritoneal Sclerosis

Encapsulating peritoneal sclerosis (EPS) is an infrequent, but extremely serious complication of long-term peritoneal dialysis. The cause of EPS is unclear, but the low incidence suggests that it is most likely multifactorial. The elucidation of developmental pathways and predictive markers of EPS would facilitate the identification and management of high-risk patients.

Animal models are often used to define pathways of disease progression and to test strategies for treatment and prevention in the patient population. Ideally such models could help to define the cause of EPS and its developmental pathways, to facilitate the identification of contributing factors and predictive markers, and to provide a system to test therapeutic strategies.

Researchers have studied several rodent models of EPS that rely on chronic chemical irritation (for example, bleach, low-pH solution, chlorhexidine gluconate) to induce peritoneal sclerosis and abdominal encapsulation. Development in all models is progressive, with inflammation giving way to peritoneal fibrosis or sclerosis with accumulating membrane damage, culminating in cocoon formation. Microscopic findings are similar to those proposed as diagnostic criteria for clinical EPS: an initial inflammatory infiltrate and submesothelial thickening, collagen deposition, and activation and proliferation of peritoneal fibroblasts. The potential to block progression of peritoneal sclerosis in these models by anti-inflammatory, antifibrotic, and antiangiogenic agents, and by inhibitors of the renin–angiotensin system have been demonstrated.

Animal models based on clinically relevant risk factors (for example, uremia, peritonitis, and long-term exposure to dialysis solutions) now represent the next step in model development.

Long-Term Peritoneal Dialysis is a Risk Factor of Sclerosing Encapsulating Peritonitis for Children

Objective

Sclerosing encapsulating peritonitis (SEP) is a clinical syndrome with a high mortality rate and is a serious complication of peritoneal dialysis (PD). Peritoneal sclerosis (PS) is a histological diagnosis. PS is usually observed in the peritoneal specimens of patients with SEP. Avoiding SEP is considered to be extremely important for pediatric patients who may require long-term PD. In this study, the characteristics of patients with PS were investigated to determine when to perform peritoneal biopsies and how long PD can be performed safely.

Design

A retrospective single-center study.

Setting

Tokyo Metropolitan Kiyose Children's Hospital.

Patients

A total of 109 children younger than 16 years have received chronic PD in our unit since 1981. Among these children, 16 patients had been on PD for more than 5 years (mean 7.4 ± 2.5 years) from May 1992 to March 1999. Peritoneal biopsies were performed in 14 of the 16 patients, who were divided into two groups based on the histological diagnoses: a PS and a peritoneal fibrosis (PF) group.

Results

The 14 patients were on PD for a mean of 7.8 ± 2.5 years. There were 8 patients with PS and 6 patients with PF. SEP was observed in 2 patients in the PS group. The risk of PS increased with the duration of PD: 57% (8/14) > 5 years, 80% (4/5) > 8 years, and 100% (3/3) > 10 years. All patients in the PS group showed both peritoneal calcifications on abdominal CT scan and poor ultra-filtration at the time of diagnoses.

Conclusion

Long-term PD was the important risk factor of SEP. If both peritoneal calcification on abdominal CT scan and poor ultrafiltration are observed in a patient on PD more than 5 years, a peritoneal biopsy should be performed. If PS is detected, PD should be discontinued.

A Historical Review of Encapsulating Peritoneal Sclerosis

Publications providing insights into the pathophysiology of, and therapeutic strategies for, EPS are the focus of the present review. Referenced publications are limited to those written in English.

Hemoperitoneum: Bloody Peritoneal Dialysate in Esrd Patients Receiving Peritoneal Dialysis

Hemoperitoneum is seen in patients receiving peritoneal dialysis (PD) because the PD catheter provides a window to the peritoneum. Gynecological associated phenomena account for the majority of cases. Intra-abdominal pathology of solid organs such as the kidney, liver, and spleen as well as the gastrointestinal tract is recognized. Unique to PD patients, hemoperitoneum may be associated with the catheter itself, uremic bleeding, or peritonitis. A successful PD program requires nephrologists, PD nurses, and patients assess and manage hemoperitoneum in a systematic fashion. This paper reviews hemoperitoneum in adult PD patients.

Ossification of the Peritoneal Membrane

Background

Peritoneal dialysis (PD) patients rarely develop sclerosing peritonitis (SP), a severe, life-threatening condition of unknown pathogenesis. Ossification of the peritoneum (PO) is a rare occurrence, which has, however, been reported in PD patients with SP.

Objective

To investigate etiopathogenetic correlations between PO and SP by histopathological examination.

Method

We examined biopsy specimens, obtained by laparoscopy or during surgery from 36 patients with SP, from all parts of Italy in the past 8 years for evidence of peritoneal calcification or ossification. Other studies were performed on a sample of dense white material found under the parietal peritoneum of 1 patient during laparoscopy.

Results

Ossification of the peritoneum was found in 4/16 patients with calcifications. In addition to PO, we also found bone marrow in two specimens and arterial ossification in one case. In specimens with calcifications, and especially those with ossification, there was evidence of peritoneal inflammation with infiltration of lymphocytes, multinuclear giant cells, macrophages, and mast cells. The chemical composition of the whitish material was 85% calcium chloride and 15% hydroxyapatite.

Conclusions

Calcifications alone were found in 33% (12/36) of cases of SP; 11% of SP cases were complicated by both peritoneal calcification and ossification (4/36), which indicates great availability of calcium under conditions of inflammation. Where does this calcium come from? In 1 patient with PO, the quantity of calcium was enormous and its unusual composition suggested a link with the calcium contained in dialysis solution.