Renal angiomyolipoma (AML) is the most common benign renal tumor. Whilst generally asymptomatic, they can cause life-threatening bleeding. Selective angioembolization (SAE) may be used to treat large symptomatic and asymptomatic AMLs. We aimed to evaluate the efficacy of SAE for symptomatic and asymptomatic renal AMLs and determine characteristics that predict spontaneous bleeding. Patients and Methods: Data were retrospectively collected from a prospectively maintained database from July 2011 to April 2022. Patients were included if AML was >4cm and they underwent subsequent SAE. Follow-up imaging was analyzed to calculate mean reduction in AML size. Clinical notes were reviewed to analyze lesion characteristics including vascularity, fat content and presence of aneurysm as well as post-procedural complications. Results: 26 patients with 30 AMLs were identified. Interval of follow-up imaging ranged from 1 to 60 months. 25 AMLs were embolized electively with 5 emergency embolizations performed for bleeding. Mean reduction in AML volume was 41% at 3 months (p=0.013) and 63% at 12 months (p=0.007). All 5 bleeding AMLs had a rich vascularity with 60% also having either aneurysms or a low fat content. Complications included post-embolic syndrome (n=9), segmental renal parenchyma devascularization (n=3), acute bleeding requiring re-embolization (n=2), nephrectomy for ongoing bleeding (n=1) and delayed bleeding managed conservatively (n=1). No deterioration in renal function was observed. Conclusion: SAE is an effective procedure for managing symptomatic and asymptomatic renal AML, with minimal significant complications. AML vascularity, fat content and aneurysms may be useful characteristics to assess future risk of bleeding in patients with renal AML.

Objective: The objective was to determine whether giant renal angiomyolipomas (AMLs) can be managed through selective angioembolisation (SA) and compare outcomes to nephron-sparing surgery (NSS) and nephrectomy. Methods: A retrospective case series was compiled from a prospectively maintained database, commenced in 2011 of renal AMLs that underwent SA. We extracted patient demographics, size of AMLs, intervention and outcomes. A literature review of case reports and case series was performed on the management of giant renal AMLs managed through SA, NSS or nephrectomy. Results: Of 30 AMLs that underwent SA, 6 patients met the inclusion criteria. The mean diameter of AMLs prior to embolisation was 14.3 cm. All embolised AMLs decreased in size post-embolisation by an average of 18% (mean: 39-month follow-up). There were no complications in our cohort’s follow-up period, including no rise in any patients’ creatinine associated with SA. Our literature review of 284 articles found 82 articles pertaining to 102 giant renal AMLs. Our review identified SA, NSS and nephrectomy to all be effective management pathways for giant AMLs with minimal complications. Total nephrectomy did result in five patients requiring dialysis post-procedure. Conclusions: SA is an effective intervention for giant AMLs with comparable outcomes to NSS and nephrectomy and should be considered a suitable management option for giant renal AMLs. Level of evidence: Not applicable