Renal papillary necrosis - A sixteen-year clinical experience

This study sought to characterize patients with renal papillary necrosis seen at one tertiary referral center by reviewing medical records of patients with a confirmed diagnosis between January 1, 1976 and September 1, 1992. One hundred sixty-five cases were identified. The mean age at diagnosis was 57 yr (SD 15). The female-to-male ratio was 1.1:1.0. Ninety-two percent of patients were white. Seventy-seven percent of cases were unsuspected before diagnosis, and 16% were diagnosed at autopsy. The most common associated conditions were urinary tract infection, analgesic abuse, urinary tract obstruction, diabetes mellitus, and sickle cell disease. There was considerable overlap in the presence of these conditions, with two or more identified in 36% of patients. In addition, 11% of patients had none of these well-recognized risks. Other diagnoses in this group included lupus nephritis, Wegener's granulomatosis, and renal artery stenosis. A decline in case numbers of approximately 50% was demonstrated over the last 10 yr studied. This period was associated with a 57% reduction in the number of excretory urograms carried out, suggesting that changes in diagnostic imaging preference may have contributed. Vital status and renal outcome data after diagnosis were obtained in 93% of cases. Of those diagnosed while living, survival was lowest among diabetic patients. Ten-year survival for nondiabetics was not significantly different from the expected survival of an age- and sex-matched cohort. The overall risk for requiring renal replacement therapy after the diagnosis of renal papillary necrosis in surviving patients was low (7% of 136 patients at risk). Diabetes was the only factor associated with an increased risk of end-stage renal failure. This study emphasizes that continued recognition of papillary necrosis will necessitate an awareness of its clinical spectrum in the context of current diagnostic and therapeutic practice.