[Acquired stenosis of the upper urinary tract after percutaneous nephrolithotomy]

The authors present two well documented cases of extensive acquired stenosis of the infra-pelvic upper urinary tract following percutaneous nephrolithotomy. This type of complication appears to be exceptional as, by combining the series of two centres, it represents only two cases out of more than five hundred cases treated. The delay in appearance is of the order of six months. The more or less complex nature of the procedure does not appear to be responsible. It is difficult to determine the exact mechanism fo this complication: several hypotheses are proposed. A few rare cases have been reported in the literature without raising any particular attention. These complications required difficult reconstructive surgery with a good result in both cases. Although these complications seem to be difficult to prevent, they should be systematically detected by ultrasonography at two months and at six months to avoid delay in the diagnosis of functional renal exclusion.