To describe the indications, methods, efficacy and complications of transarterial management of renal angiomyolipomas (AMLs) in both elective and emergency settings.
Materials & Methods
A retrospective analysis of eight patients with nine renal angiomyolipoma treated in our centre from October 2004 to March 2008. Tumour size ranged from 5.0 cm to 10.5 cm. Six cases underwent prophylactic embolisation for large symptomatic as well as incidental angiomyolipomas whilst three cases required emergency embolisation due to presentation of acute retroperitoneal bleed.
Teaching Points
Renal AMLs are uncommon benign hamartomas composed of fat, smooth muscles and aggregates of thick-walled blood vessels with incomplete elastic layers. The incomplete elastic layers make the tumor blood vessels prone to aneurysmal formation and bleeding. Indications for embolization includes symptomatic tumours, high risk of morbidity or mortality due to surgery and patients' desire to obviate surgery. Large tumours (> 4cm) are more likely to present with spontaneous hemorrhage and therefore candidates for elective management to prevent bleeding and associated complications. The treatment options include surgery and transarterial embolization where the latter is preferred as it is minimally invasive. Surgery is performed when transarterial management fails to control the bleeding. We describe the imaging appearances of renal AMLs on ultrasound, CT, MRI and catheter angiography. The angiographic appearances and transcatheter management of the AMLs with different embolic materials will be illustrated with examples. The present accepted strategy of renal AML embolization is preservation of the normal renal parenchyma by super selective embolization of tumor vessels only. The various embolic agents used include gelfoam, poly vinyl alcohol (PVA) particles, metallic coils, absolute alcohol, and iodized oil. The reported complication rate with transarterial embolization is about 10% and most commonly is an abscess formation. Transarterial management of renal AMLs is an effective and safe procedure in both elective and emergency settings.
National University Hospital, Singapore, Singapore
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