Endovascular embolization in the surgical treatment of renal angiomyolipoma

Introduction. Angiomyolipoma (AML) is the most common benign renal tumor. Selective arterial embolization of AML-feeding vessels is currently regarded as an effective organ-preserving treatment. However, the absence of unified criteria for predicting procedural success limits its widespread adoption.
Objective. To evaluate the outcomes of endovascular embolization of renal AML according to tumor angioarchitectonic type.
Materials & methods. This retrospective study included 30 patients with renal AML who underwent endovascular embolization between 2021 and 2024. Based on angiographic findings, all AMLs were classified into three types according to their vascular supply: type I (poor vascularization), type II (up to two major feeding arteries), and type III (multiple feeding arteries). Embolization was performed in patients with type II and III vascular patterns. Technical success of embolization, as well as changes in tumor size and volume at 6 and 12 months, were assessed.
Results. The distribution of AMLs by vascular type was as follows: type I in 5 (17%) patients, type II in 16 (53%), and type III in 9 (30%). Embolization was technically not feasible in type I. Overall embolization success was achieved in 88% of cases (22 patients). Technical success was 100% for type II (16/16) versus 66.7% for type III (6/9). Statistical analysis demonstrated that the probability of successful embolization was 3.67 times higher for type II compared with type III (OR 3.67; 95% CI 1.85–7.26; p = 0.014). In all cases of successful embolization, a significant reduction in AML size and volume was observed during long-term follow-up.
Conclusion. Selective embolization is an effective treatment for renal AML, achieving substantial tumor shrinkage. The proposed classification of AML vascular types is a clinically useful tool that allows stratification of patients by likelihood of technical success at the diagnostic angiography stage. The best embolization outcomes were observed in patients with type II angioarchitecture.

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