Objective: The purpose of our study was to determine whether two injections of sclerosant were more effective than a single injection in treating symptomatic simple renal cysts.
Subjects and methods: We reviewed our results obtained by simple aspiration, by aspiration and a single sclerosant injection, and by aspiration followed by two injections of sclerosing agent over 48 hr. We used 95% alcohol because of its capacity to safely sclerose the epithelial lining of renal cyst walls without damaging the renal parenchyma. After 1-3 min of contact with the alcohol, the epithelial cells lining the cyst become fixed and nonviable; the cyst capsule is penetrated only after 4-12 hr. Longer contact of alcohol with the epithelial cell lining should theoretically result in the nonviability of more epithelial cells and therefore in a lower recurrence rate of cysts after aspiration and sclerotherapy. Our subjects were 46 patients, 30 men and 16 women, treated over a 13-year period. They ranged in age from 38 to 75 years old (mean age, 47 years). Fifty-two cysts were treated. Twenty patients (20 cysts) had simple aspiration only, 15 patients (19 cysts) had a single injection of sclerosant after aspiration, and 11 patients (13 cysts) had two sclerosant injections after aspiration.
Results: Of the 20 patients who had simple aspiration only, 16 cysts had recurred after 2 years. In the single-injection group of patients, we found six recurrences after 2 years. No recurrence has occurred in the group of patients who had two sclerosant injections after aspiration.
Conclusion: Our findings suggest that the results of treating symptomatic simple renal cysts are better in terms of recurrence with two successive injections of 95% alcohol, probably because of the nonviability of more epithelial cells lining the cyst as a result of a longer period of contact with the alcohol. Our sonographic finding of pseudotumors at the sites of previously aspirated giant cysts in two patients is recorded.