Transarterial Embolization of Angiomyolipoma: A Systematic Review

INTRODUCTION: Transarterial embolization is increasingly used in the management of renal angiomyolipoma. The level of evidence establishing the safety and efficacy of transarterial embolization has not increased in parallel. MATERIALS AND METHODS: Using the MOOSE (Meta-analysis Of Observational Studies in Epidemiology) criteria a systematic review of transarterial embolization of angiomyolipoma was performed to establish procedural safety and efficacy. A MEDLINE® PubMed® search revealed 1,739 publications, of which 31 studies met eligibility criteria. RESULTS: A total of 524 cases of transarterial embolization of angiomyolipoma were included in analysis. Self-limiting post-embolization syndrome developed following 35.9% of embolizations and further morbidity developed in 6.9%. No procedural mortality was reported. At a mean followup of 39 months the mean size reduction was 3.4 cm (-38.3% of angiomyolipoma diameter). Unplanned repeat embolization or surgery was required in 20.9% of cases during this period. The most frequent indications for repeat procedures included angiomyolipoma revascularization in 30.0% of cases, unchanged or increasing size in 22.6%, refractory or recurring symptoms in 16.7% and representation with acute retroperitoneal hemorrhage in 14.3%. Treatment included a combination of 2 or more embolic agents in 46.8% of cases, ethanol monotherapy in 41.7%, coil monotherapy in 6.2% and foam or microparticle monotherapy in 5.2%. CONCLUSIONS: Transarterial embolization of angiomyolipoma demonstrates low rates of mortality and serious complications. Re-treatment rates and size reduction at a mean followup of 39 months are presented. Longitudinal data assessing long-term size reduction and re-treatment rates are lacking. Recommendations guiding the indications for transarterial embolization and clear followup require further longitudinal data.