[Ultrasonography-guided alcohol injection in simple renal cysts. Long-term results]

The percutaneous treatment of simple renal cysts must be restricted to symptomatic lesions. It consists in a guided puncture, fluid aspiration and the injection of a sclerosing agent. The authors describe the procedure they followed, which has been made possible by technical progress. It consists in US guidance, a Trocar catheter drainage set and the injection of absolute alcohol. Moreover, the long-term results are reported of a retrospective study of 69/148 treated patients who underwent one or more US exams 15 days to 5 years after the procedure. Eleven of 69 patients (15.9%) exhibited complete regression, 42 of 69 (60.9%) had lesion relapse < 5 cm phi and 16 of 69 (23.2%) had > 5 cm relapse. On the whole, 53 (76.8%) positive results were obtained after the first treatment; positive results were obtained after the second treatment in 4 of 16 patients with > 5 cm relapse. US follow-up showed changes in the sizes of the relapsed cysts, which sometimes shrunk in the long run. All treated cysts reduced in volume; nevertheless, it would be useful to look for new sclerosing agents allowing a higher rate of complete regressions.