Embolic Agent Selection and Outcomes in Renal Angiomyolipoma Embolisation

PURPOSE: To evaluate whether embolic agent selection influences outcomes following selective arterial embolisation (SAE) of renal angiomyolipomas (r-AMLs) and to assess procedural safety and effects on renal function. MATERIALS AND METHODS: A retrospective observational study was performed of all r-AML SAEs undertaken at a tertiary institution between 2015 and 2024. Change in tumour size on pre- and 3-6-month post-procedural imaging was the primary outcome. Secondary outcomes included technical success, re-intervention rates, complications (Clavien-Dindo), renal function change and length of hospital stay. Outcomes were compared across embolic agents including microparticles, liquid embolic agents, coils and combined approaches. RESULTS: Forty-nine patients (51 lesions) underwent angiography, with SAE attempted in 54 procedures. Technical success was achieved in 91%. Tumour size reduction occurred in 91% of lesions with follow-up imaging, with a mean reduction of 1.75 cm (p < 0.0001). Liquid embolic agents alone demonstrated the greatest mean tumour reduction with a mean reduction of 2.4 cm and a 0% re-intervention rate. Microparticles alone achieved significant size reduction with a low re-intervention rate, while coil-only embolisation was associated with inferior outcomes and higher re-intervention rates. Combined embolisation strategies achieved significant tumour reduction but did not outperform liquid agents alone. Complications occurred in 10% of patients and were predominantly minor. No patient required renal replacement therapy, and the median eGFR did not change significantly. CONCLUSION: SAE is a safe and effective treatment for r-AML in both elective and emergency settings. Liquid embolic agents achieved the greatest tumour reduction with low re-intervention rates, while coil-only embolisation showed inferior outcomes and should be avoided where possible.