Polycystic kidney size and outcomes on peritoneal dialysis: comparison with haemodialysis

BACKGROUND For many nephrologists, patients with polycystic kidney disease (PKD) have an increased risk of complications and technique failure on peritoneal dialysis (PD) due to enlarged kidneys. The literature showed that PD can be as good a therapeutic option as haemodialysis (HD) for patients with PKD. However, no study has focused on the impact of polycystic kidney size on outcomes for patients on PD. METHODS This is a retrospective monocentric study. Fifty-eight patients with PKD started dialysis between January 2000 and December 2010: 24 on PD and 34 on HD. Kidney size assessed by abdominal computed tomography scans was available for 45 patients (19 on PD and 26 on HD). PD technique survival, specific PKD complications and mechanical and infectious PD complications, as need for pre-transplant nephrectomy and kidney transplantation, were considered. RESULTS The two cohorts were similar in terms of age and body surface area. The median kidney size was not significantly different between PD and HD patients [19.1 cm (12.5-32.5) versus 16.5 cm (11.8-33.8), respectively, P = 0.13]. However, we identified an increased number of PD patients with larger kidneys [(>25 cm) (27.8% on PD versus 7.7% on HD (P = 0.07)]. Neither cystic (infection or haemorrhage) nor mechanical complications (hernias and leaks) were different in PD or HD. Ten patients experienced PD-related peritonitis, mainly due to non-enteric bacterial pathogens. The main reason for stopping PD and HD was transplantation. Six PD patients underwent nephrectomy in order to access the transplant programme. Among them, five were maintained on PD after surgical procedure with good adequacy dialysis criteria. CONCLUSIONS We observed no deleterious impact of kidney size on outcomes on PD when compared with HD. A large kidney size in patients with PKD is not a contraindication to PD. Patients for whom a pre-transplant nephrectomy is mandatory can also safely opt for PD as a dialysis method.