The spectrum of peritoneal fibrosing syndromes in peritoneal dialysis.

A variable degree of diffuse peritoneal fibrosis has been documented in all patients who have been on long-term peritoneal dialysis. Peritoneal dialysis-induced diffuse peritoneal fibrosis varies from opacification and "tanning" of the peritoneum, which may have only a moderate detrimental effect on peritoneal transport kinetics, to a progressive, sclerosing encapsulating peritonitis (SEP), which may lead to cessation of peritoneal dialysis and to death. Fewer than 1% of peritoneal dialysis patients develop overt SEP as manifested by combinations of intestinal obstruction, weight loss, and ultrafiltration failure. The diagnosis of SEP depends on a combination of laparotomy and radiological features in suspected cases and consequently the true incidence of SEP is most likely underestimated. Several predisposing, interrelated risk factors for both peritoneal fibrosis and sclerosing encapsulating peritonitis have been identified: prolonged duration of peritoneal dialysis, history of severe or recurrent episodes of peritonitis, and higher exposure to hypertonic glucose-based dialysis solutions. Nevertheless, the etiology of SEP is unknown and several causal factors may simultaneously or sequentially initiate and maintain a low-grade serositis that leads to uncontrolled fibroneogenesis. The high mortality rate of SEP has emphasized the need to develop preventive strategies. These strategies include early peritoneal catheter removal to avoid refractory peritonitis, the development of more biocompatible dialysis solutions, restriction of the use of hypertonic glucose-based dialysis solutions during and after episodes of peritonitis, and, perhaps, limiting the duration of peritoneal dialysis in at-risk patients. This approach was followed in a Japanese unit where a subgroup of all patients who had been on peritoneal dialysis for more than 5 years and who had poor ultrafiltration and peritoneal calcification on computed tomography (CT) scan were shown to have peritoneal sclerosis on peritoneal biopsy and were therefore electively transferred to hemodialysis. This acquired spectrum of peritoneal fibrosing syndromes leads to long-term complications in peritoneal dialysis, whereas localized fibrous adhesions secondary to prior abdominal surgery may prevent the successful initiation of peritoneal dialysis.