Radiologically guided percutaneous aspiration and sclerotherapy of symptomatic simple renal cysts: a systematic review of outcomes.

Simple renal cysts are common benign lesions of the kidney with up to 4% of patients developing symptoms necessitating intervention including pain and haematuria. We conducted a systematic review of the literature to determine the efficacy and safety of aspiration-sclerotherapy of symptomatic simple renal cysts. A systematic review using Cochrane guidelines was conducted on published literature from 1990 to 2020. RCTs, cohort studies and case series meeting the inclusion criteria were reviewed and cumulative analysis of outcomes was performed. A total of 4071 patients from 57 studies underwent aspiration ± sclerotherapy for their simple renal cysts. 87.7% of patients who had aspiration with sclerotherapy demonstrated 'treatment success' with a >50% reduction in cyst size and complete resolution of symptoms. 453 minor, transient complications occurred (11.2%) whilst a major complication rate of less than 0.1% (4 patients) was reported. Pooled analysis of all available current literature demonstrates that aspiration-sclerotherapy is a safe and effective first-line therapy for symptomatic simple renal cysts. Although we are unable to compare those undergoing aspiration alone to aspiration-sclerotherapy, it is evident the use of a sclerosing agent is integral to treatment success; however, the optimum agent, volume, injection frequency, and dwelling time are yet to be defined. Cyst size should be considered when discussing treatment options; however, we conclude it reasonable for aspiration-sclerotherapy to be used in the first instance in all cases of symptomatic simple renal cysts. Furthermore, we propose definitions of treatment outcome measures in order to allow direct comparative analysis across future studies.