[Recurrence of upper urinary tract calculi].

Treatment of upper urinary tract stones has changed greatly. The recurrence of calculi after the discharge was studied in the 634 patients with urolithiasis admitted to our department during the 9 years up to the end of 1984. The recurrence rate in the 325 cases followed for more than 3 months after the disappearance of the original stones, was 15.6% after 2 years, 27.6% after 5 year and 51.4% after 8 years. In recurrent stone formers, the rate of recurrence thereafter was greater than that of primary stone formers. The growth of calculi was rapid in the renal stone former concomitant with urinary tract infection together with a past history of renal surgery. In relation to the composition of the stone, uric acid calculi tended to recur more often than calculi composed of other substances. In view of recurrence, pyelolithotomy is preferred to renal parenchymal incision.