Peritoneal sclerosis in chronic peritoneal dialysis patients: analysis of clinical presentation, risk factors, and peritoneal transport kinetics

OBJECTIVE: To analyze clinical features of peritoneal sclerosis (PS) in a group of peritoneal dialysis (PD) patients, and to compare potential risk factors and peritoneal transport characteristics with a control group matched for duration of PD. DESIGN: Study 1: Retrospective study of 16 PD patients with PS. Study 2: Case-control study comparing 10 patients with evident PS to 30 control patients who were matched for duration of PD. SETTING: Continuous Ambulatory Peritoneal Dialysis unit in the Academic Medical Centre in Amsterdam. RESULTS: The incidence of PS was 3.5 per 1000 patient years. PS was diagnosed either during PD (n = 10), in patients on hemodialysis (n = 2), or after successful transplantation (n = 4). Presenting symptoms were bowel obstruction, ascites, blood-stained effluent, and impaired net ultrafiltration. Macroscopic confirmation of the diagnosis was possible in 13 patients. Sclerotic encapsulation was present in 8 of them. Patients with PS were divided into three groups based on clinical symptoms and typical macroscopical findings. In category I the diagnosis PS was obvious (10 patients), in category II the diagnosis was highly suggestive (3 patients), and in category III it was doubtful (3 patients). Treatment was conservative in most patients. Surgical treatment was only possible in four and immunosuppressive therapy was given in 5 patients. Peritoneal sclerosis was the direct cause of death in 1 patient. Five patients died during follow-up due to other causes. At present, 7 patients are well and 3 patients (all from category I) still have recurrent bowel obstruction. Compared to matched controls, no difference existed in peritonitis incidence, or in the percentage of patients with former renal transplantations. The number of patients treated with beta-blocking agents and the number of previous abdominal surgeries were not different. The number of catheter-related surgical procedures was higher in the PS patients than in the control group. The mass transfer area coefficient (MTAC) of creatinine was higher in PS patients and net ultrafiltration with 1.36% glucose was lower. The estimated cumulative glucose exposure until the diagnosis of PS was made was larger in PS patients than in their controls. This difference was already present in the first year of PD treatment in 8 of 10 patients. The initial values for the MTAC creatinine were similar in both groups. CONCLUSIONS: The presenting symptoms of PS were bowel obstruction, ascites, and blood-stained effluent, often in combination with loss of net ultrafiltration. Peritoneal sclerosis is a complication of long-duration PD and could also become manifest after a successful renal transplant. Treatment should be conservative unless complications require surgical intervention. Patients with PS had lower net ultrafiltration and higher transport rates compared to controls who were matched for duration of PD. Although peritonitis incidence was similar, a relation of PS with severe peritonitis may be present in some patients. Glucose exposure is likely to be an important risk factor for PS