[Percutaneous renal cyst puncture and ethanol instillation].

Under ultrasound guidance 79 simple renal cysts in 65 patients were punctured and aspirated with our contrivance, a 5 Fr single J catheter on a 19 gauge needle. Forty-eight renal cysts were successfully punctured, that is, they had no bloody fluid and did not have any leakage of contrast medium. These cysts were instilled with absolute ethanol for 5 minutes. To follow up the patients, consecutive observation was done by sonography or CT every three months. Ethanol-instilled renal cysts were more markedly reduced (reduction rate: 93 +/- 17%) than not-instilled cysts (reduction rate: 32 +/- 28%). Thus, ethanol-instillation was useful in the reduction of renal cysts. After the puncture of cysts, hematuria disappeared in most patients.