Efficacy of single-session 99.5% ethanol sclerotherapy for incidentally found simple renal cysts

Simple renal cysts are the most common masses in the kidney. Most are asymptomatic and are incidentally detected on imaging examinations performed for other reasons. This study aimed to compare the results of 40 and 120 minutes ethanol sclerotherapies that were performed in a single session to treat incidentally found simple renal cysts. We retrospectively reviewed 63 renal cysts in 62 patients treated by single session percutaneous ethanol sclerotherapy. Thirty-one patients with 32 cysts underwent a 40 minutes sclerotherapy (group A), and 31 patients with 31 cysts underwent a 120 minutes retention technique (group B). Under ultrasonographic and fluoroscopic guidance, cystic fluid was completely aspirated, and 50% of the aspirated volume was replaced with 99.5% ethanol (a maximum of 100 mL). Imaging follow-up of the patients was performed 3 months after sclerotherapy. The technical success rates were 100% in both groups. Eighteen patients (29.0%) were symptomatic (flank pain or discomfort). Indications of the other patients were large cysts (>5 cm; 46%) and an increment in the diameter on serial studies (25.4%). A significant difference between the 2 groups in terms of age, cyst diameter, volume of aspirated fluid, volume of injected ethanol, and percentage of reduction in cyst diameter (P > .05) was not found. After treatment, flank pain or discomfort resolved in 17 of 18 (94.4%) symptomatic patients. One patient complained of persistent flank pain; however, no significant abnormality was detected on post-procedural computed tomography images. There were no other complications after therapy in the 2 groups. Single session ethanol sclerotherapy with a 40 minutes retention technique is an effective, safe, and cost-effective method for the treatment of incidentally found simple renal cysts. Although the procedural time was reduced, there was no significant difference in therapeutic efficacy between the 40 and 120 minutes therapies.