URINARY CALCULI AS A LATE COMPLICATION OF THE INDIANA CONTINENT URINARY-DIVERSION - COMPARISON WITH THE ROCK POUCH PROCEDURE

Purpose: Although urinary calculi have been frequent late complication s of the Rock continent urinary diversion, they have not been regarded as significant problems in patients with the Indiana pouch because of the lack of foreign material present. However, stones developed in a significant percentage of our patients with an Indiana pouch. We inves tigated the characteristics of stone formation in patients with the In diana pouch and compared them to those with a Rock pouch. Materials an d Methods: Detailed clinical courses regarding stone formation were re viewed in 72 patients with a Kock pouch and 54 with an Indiana pouch w ho had a minimum followup of 12 months. Results: Stones developed in 7 of 54 patients (12.9%) with an Indiana pouch compared to 31 of 72 (43 .1%) with a Kock pouch. The incidence gradually increased with longer followup but it was lower in the Indiana than in the Kock pouch group (5-year stone-free rate 84% versus 66%, respectively). Although the st ones consisted principally of a mixture of struvite, carbonate apatite and ammonium hydrogen urate, variable amounts of calcium oxalate were identified in 50% of the Indiana pouch calculi. Conclusions: Not only urinary infections but also metabolic factors were considered to be i nvolved in stone formation within the Indiana pouch. However, the subs tantially higher rate of stone formation in our Kock and Indiana pouch groups than has been reported in the United States suggested that no or infrequent pouch irrigations in our patients were important risk fa ctors for urinary calculi.