Peritoneal calcification associated with continuous ambulatory peritoneal dialysis

Imaging Work-Up for Peritoneal Access Care and Peritoneal Dialysis Complications

Peritoneal dialysis (PD) represents a treatment opportunity for patients with end-stage renal failure, but it has particular complications that sometimes force cessation of this procedure (1–9). These complications are due to the presence of the peritoneal catheter and of dialysis solution within the peritoneal cavity. Infections are the most common complications of PD, followed by mechanical complications.

Diagnostic imaging of the complications of PD is important because such an evaluation can aid in the diagnosis and in the decision making process about the treatment. In this review we present the main radiologic investigations employed: plain radiograph, US, peritoneography, computed tomography peritoneography, magnetic resonance peritoneography, peritoneal scintigraphy.

To diagnose catheter-related problems plain radiograph, ultrasonography and peritoneography can be useful. US is useful in diagnosing and following-up exit-site and tunnel infections. Peritoneography and C T-peritoneography, alone or in combination, can be recommended as gold standard investigation to assess mechanical peritoneal dialysis complications, such as catheter malfunction, leaks, hernias and sclerosing peritonitis. Newer methods, such as MR peritoneography or scintigraphy could be useful in selected patients, on center-based experience. An appropriate use of radiology may significantly improve technique survival, morbidity and mortality of patients treated with PD.

High peritoneal KT/V and peritonitis rates are associated with peritoneal calcification

Background

Peritoneal calcification (PC) is a specific finding in patients undergoing peritoneal dialysis (PD), but its prevalence, risk factors, and impacts in PD patients remain unclear. The present study investigated these issues and provided information useful for the management of PC.

Methods

The study included 183 PD patients. The severity of PC was determined using abdominal computed tomography (CT), and we summed up all scores from slices obtained from the diaphragm to the pelvic floor normalized to body surface area. We analyzed the associations between PC and demographic and clinical characteristics, and between PC and levels of biomarkers, including C-reactive protein (CRP), osteoprotegrin and fetuin-A. The determinants of PC were examined using multiple regression analysis.

Results

Patients were categorized into group 1 (without PC, n = 133) and group 2 (with PC, n = 50). Group 2 patients showed different degrees of PC with a mean of 160±769 mm²/m². Group 1 patients had higher fetuin-A levels than group 2 patients (861±309 vs. 760±210 µg/mL; p = 0.021). The independent risk factors for the presence of PC included male gender, previous peritonitis, and PD adequacy (KT/V). Further analysis performed in group 2 patients showed that the dosage of vitamin D, serum levels of CRP, and dialysate calcium load were the independent determinants of PC. However, the presence of PC did not affect patients’ technique survival, peritonitis incidence, or mortality in the mean follow up period of 28±12 months.

Conclusions

The presence and severity of PC were associated with inflammation, peritoneal KT/V, and mineral metabolism. The impact of PC on the outcomes of PD patients requires further study with a longer follow-up.

Are peritoneal calcifications in long-term peritoneal dialysis related to aortic calcifications and disturbances in mineral metabolism?

BACKGROUND

Peritoneal calcifications are associated with long-term peritoneal dialysis (PD). Case reports have suggested a relation with disturbances in mineral metabolism such as the presence of severe hyperparathyroidism. Our aim was to investigate whether relationships are present between peritoneal calcifications and aortic calcifications or disturbances in mineral metabolism in long-term PD patients.

METHODS

We included all long-term PD patients (PD ≥ 4 years) in our centre from 1996 to 2008 who had undergone an abdominal computed tomographic (CT) scan. The scans were reviewed by two experienced radiologists in consensus. The presence or absence of peritoneal calcifications was scored, and a severity scoring system for abdominal aortic calcifications was used: 1 = none, 2 = mild, 3 = moderate, 4 = severe and 5 = very severe. For each patient, laboratory data on plasma calcium corrected for albumin, phosphorus and parathyroid hormone (PTH) levels were retrieved every 6 months up to 5 years prior to the CT scan. Individual mean values over 5 years were calculated.

RESULTS

We included 31 patients: 12 patients with peritoneal calcifications and 19 patients without. No difference was found in aortic calcification scores (median scores: 3 versus 3). Also, median (range) calcium, 10.7 (9.6-11.5) versus 10.3 (9.4-11.3) mg/dL; phosphorus, 5.2 (3.4-7.0) versus 4.9 (2.9-6.5) mg/dL; and PTH levels, 271 (101-910) versus 263 (40-1197) pg/mL were not different between patients with and without peritoneal calcifications.

CONCLUSIONS

The presence of peritoneal calcifications in long-term PD patients could not be related to the presence of aortic calcifications or disturbances in mineral metabolism. Perhaps, local peritoneal factors play a role in the formation of peritoneal calcifications.

Peritoneal sclerosis: one or two nosological entities?

The frequency, pathology, animal models, pathogenesis, clinical manifestations, diagnostic criteria, therapy and prevention of peritoneal sclerosis are reviewed. Many of these aspects have a bimodal configuration which suggests that peritoneal sclerosis, usually considered a single pathology in peritoneal dialysis, is actually two distinct nosological entities: simple sclerosis and sclerosing peritonitis. The former is very frequent, with minor anatomical alterations and low clinical impact; it is reproducible in animals by means of peritoneal dialysis, and is clearly due to the poor biocompatibility of peritoneal dialysis solutions. The latter is rare, with radical anatomical alterations and high mortality requiring valid methods of diagnosis, therapy and prevention; it can only be reproduced in animal models by means other than peritoneal dialysis and seems to be due to factors both related and unrelated to peritoneal dialysis.

CT appearance of sclerosing peritonitis in patients on chronic ambulatory peritoneal dialysis

PURPOSE

The purpose of this study was to describe the CT appearances of sclerosing peritonitis (SP) in patients on chronic ambulatory peritoneal dialysis (CAPD) and to compare these findings with the CT appearances in a control group of CAPD patients who did not develop SP.

METHOD

The CT findings in 10 patients with SP were compared with those from a "control group" of 71 patients without SP who were on long-term CAPD and had also undergone at least one CT examination. Particular reference on CT examination was made to the appearance of the peritoneum and small bowel and the presence or absence of loculated fluid collections.

RESULTS

Peritoneal abnormalities (calcification/thickening) were noted in 100%, loculated fluid collections in 90%, and small bowel abnormalities (tethering/dilatation) in 60% of the patients with SP. In the control group of patients, peritoneal abnormalities were noted in only 7%, loculated fluid collections in 15%, and small bowel dilatation in 5.7%.

CONCLUSION

Peritoneal thickening, peritoneal calcification, loculated fluid collections, and tethering of the small bowel appear to be diagnostic of SP. In a small group of patients with follow-up CT scans, new, or progression of, CT findings correlated with the clinical severity of SP.

Sclerosing encapsulating peritonitis associated with continuous ambulatory peritoneal dialysis: surgical management

Sclerosis of the peritoneum with encapsulation of the small intestine is one of the most serious complications of continuous ambulatory peritoneal dialysis (CAPD) and is associated with a high mortality rate. Its presence should be suspected in patients treated by CAPD who develop small bowel dysfunction with associated abdominal pain and progressive loss of ultrafiltration. In its severest form, it leads to complete high small intestinal obstruction and requirement for total parenteral nutrition. We report the successful surgical management of two young, severely emaciated patients who had this complication of CAPD. Each had entrapment of their bowel by a thick, fibrosed, and calcified membrane. Both were treated by surgically peeling the membrane away from the intestines.