Treatment of renal cysts with single-session percutaneous drainage and ethanol sclerotherapy: long-term outcome

Abstract

Objectives. To evaluate the safety, efficacy, and long-term outcome of single-session ethanol sclerotherapy for non-neoplastic renal cysts. Methods. In a prospective study, 32 patients with a simple renal cyst were treated with ultrasound-guided percutaneous aspiration, and no more than 100 mL sterile 99% ethanol was injected into the cyst. The procedure was performed under local anesthesia, and the patients were hospitalized overnight. The serum concentrations of alcohol immediately after the sclerotherapy and 1 hour later and the corresponding urine concentrations were measured. The mean follow-up period was 55 months (range 12 to 156). Control checkups were scheduled at 1, 3, 6, 9, and 12 months after the sclerotherapy. During the control visits, the patients underwent ultrasound measurement of the size of the cyst. The history concerning renal pain especially was evaluated by the urologist. The patients were asked if they did or did not have pain. The severity of pain was not evaluated. Results. Sclerotherapy with ethanol was performed successfully in all 32 patients with a simple renal cyst. The cyst disappeared completely in 7 patients (22%). The mean size of all cysts decreased from 7.8 cm (range 3 to 16) to 1.7 cm (range 0 to 9; P <0.0001). Before the sclerotherapy, 24 patients had symptoms due to the cyst, and 18 of these (75%) were asymptomatic after the ethanol sclerotherapy. In 2 patients the pain decreased, 2 patients were without change, and in 2 patients the pain increased. There was no correlation between the size of the cyst and the intensity of pain. No major complications occurred. The serum concentration of alcohol varied from 0 to 0.30 g/L and that in urine from 0.04 to 0.27 g/L. Conclusions. Percutaneous aspiration and sclerotherapy with ethanol for simple renal cysts is simple, fast, safe, effective, and inexpensive. The results are comparable to those reported earlier. The treatment is without major complications. We propose sclerotherapy with 99% ethanol as the primary treatment of simple renal cyst. The treatment can be done in an outpatient clinic.