Reversibility of long-standing urinary tract obstruction requiring long-term dialysis.

Urinary tract obstruction of longer than 4 to 6 weeks' duration is usually said to be irreversible. Older reports of unilateral obstruction have documented return of kidney function after longer periods of obstruction. The duration of bilateral obstruction compatible with return of life-sustaining renal function is poorly defined. We report herein three cases of long-standing urinary tract obstruction leading to apparent dialysis-dependent end-stage renal disease, where relief of obstruction eventually led to discontinuation of dialysis.