While selective arterial embolization is an accepted treatment option for patients with renal angiomyolipoma (AML) over 4 cm, embolization of very large AMLs poses unique challenges and risks. This study was conducted to evaluate the efficacy and safety of prophylactic embolization of AMLs over 10 cm in size.
Materials & Methods
16 consecutive patients (mean age=41.2; 14 females, 2 males) underwent embolization for 23 AMLs 10 cm or larger. 12 (75%) patients had tuberous sclerosis. All lesions were embolized using high flow microcatheters with ethanol (ETOH) and ethiodized oil (EO) mixed to a ratio of 7(ETOH):3(EO). Data that were retrospectively collected from the medical records and a QA database with IRB approval included pre and post treatment AML size and creatinine, technical success, volume of embolic material used, clinical success and complications.
Results
Mean pre-treatment AML size was 15 cm (range, 10-25 cm). Embolization was technically successful in all cases. 10 (62.5%) patients had all their AMLs treated in one session, while 6 (37.5%) required multiple sessions. A mean volume of 8.6 mL of the ETOH/EO mixture was administered (range, 2-20 mL) per lesion. Patients were followed for a mean of 26 months (range, 1 - 66). Mean follow-up AML size was 13.8 cm (8% decrease from pre-embolization). 2 (12.5%) patients required repeat embolization due to AML re-growth (n=1) or re-perfusion (n=1) seen on surveillance imaging 37 and 47 months after the initial treatment. One (6.3%) patient developed a clinically significant bleed 59 months after AML embolization. This required ICU hospitalization and an emergent repeat embolization. Complications following treatment occurred in 2 patients (12.5%), including a pneumothorax in one patient and a UTI in another. No patients experienced a significant (over 0.2 mg/dl) rise in serum creatinine.
Conclusion
Embolization of giant renal AMLs to decrease the risk of bleeding can be done safely without significant loss of renal function. Although recurrence was infrequent, additional treatment may be necessary and all giant renal AMLs should be followed with life-long serial imaging studies.
FULL TEXT