Purpose: To compare follow-up results of sclerotherapy for renal cyst using 50% acetic acid with those using 99% ethanol as sclerosing agents.
Methods: Eighty-one patients underwent sclerotherapy and 58 patients, 23 males, 35 females, aged 6-76 years, having a total of 60 cysts, were included in this study; the others were lost to follow-up. The renal cysts were diagnosed by sonography, computed tomography (CT), or magnetic resonance imaging (MRI). Sclerotherapy was performed using 50% acetic acid for 32 cysts in 31 patients and 99% ethanol for 28 cysts in 27 patients. Under fluoroscopic guidance, cystic fluid was aspirated as completely as possible. After instillation of a sclerosing agent corresponding to 11.7%-25% (4-100 ml) of the aspirated volume, the patient changed position for 20 min and then the agent was removed. Patients were followed up by sonography for a period of 1-49 months. The volume of the renal cyst after sclerotherapy was compared with that of the renal cyst calculated before sclerotherapy. Medical records were reviewed to analyze complications.
Results: The mean volume after sclerotherapy of the 17 cysts followed for 3-4 months in the acetic acid group was 5.1% of the initial volume, and for the 14 cysts in the ethanol group it was 10.2%. Complete regression during follow-up was shown in 21 cysts (66%) in the acetic acid group; the mean volume of these cysts before the procedure was 245 ml. The mean volume of the nine (32%) completely regressed cysts in the ethanol group was 184 ml. Mild flank pain, which occurred in three patients in each group, was the only complication and resolved the next day.
Conclusion: Acetic acid was an effective and safe sclerosing agent for renal cysts, tending to induce faster and more complete regression than ethanol.