Peritoneal Dialysis in the Patient with a Failing Renal Allograft

Abstract

Background Patients returning to dialysis treatment after a period with a functioning allograft represent a special case in the integrated care model of renal replacement therapy. They are known to nephrologists— and thus are ideal candidates for a timely commencement of dialysis—but they have had time to accrue additional cardiovascular risk. Furthermore, they have been exposed to prolonged immunosuppression. Purpose The present study aimed to establish the clinical outcomes of patients returning to peritoneal dialysis (PD) with failing allografts [survival, technique survival, longitudinal residual renal function (Kt/VR), peritoneal membrane function (solute transport), and plasma albumin] and to compare those outcomes with outcomes in new, contemporary patients. Setting The study was conducted in a single center where prospective collection of data now known to be important in determining outcome on peritoneal dialysis (age, comorbidity, albumin, Kt/VR, and solute transport) has been performed since 1989. Methods All patients commencing PD between 1989 and 2001 after failure of an allograft that had functioned for more than 6 months were identified. Outcomes in that group were compared to outcomes in all new PD patients and in all dialysis patients with failed grafts who were returning to hemodialysis (HD) in the same period. Results The study identified 45 patients with failed allografts: 28 were commencing PD treatment, and 17 were commencing HD treatment. Those patients were significantly younger than the 469 new patients commencing PD [FailedTx→ PD 41.2 years, FailedTx→ HD 38.9 years, NewPD 54.7 years; analysis of variance (ANOVA): p < 0.001]. We saw no significant difference in the survival of failed transplant patients commencing PD as compared with those commencing HD (log rank: p = 0.11). Kaplan–Meier plots of patient survival were better for failed transplant patients as compared with all new PD patients. When corrected using Cox regression, the survival advantage was seen to be due to age and comorbidity at start of PD. Pure technique failure (excluding death) was not different between the groups. Compared with all new PD patients, patients with failed allografts had similar longitudinal plasma albumin and a tendency toward an earlier increase in solute transport, but a more rapid loss of Kt/VR, ( p < 0.05 at 6 – 48 months). Conclusions Peritoneal dialysis would appear to be a good option for patients with failing allografts. Co-morbidity is the predominant determinant of survival. That finding underlines the need for attention to factors that might prevent accrual of cardiovascular risk during the post-transplantation period. The earlier loss of Kt/VR in those patients might be prevented by developing strategies of continued immunosuppression after commencement of dialysis, although infection risk is an important issue.