Endovascular treatment of renal angiomyolipomas: Mid-term and long-term results

Objective: Angiomyolipoma is the most common benign tumor in the kidney, which usually grows slowly and does not require treatment. However, treatment of large, rapidly growing, symptomatic and bleeding lesions with a distinctive vascular component is recommended. In our study, it was aimed to evaluate the mid-term and long-term outcomes of patients with renal angiomyolipomas treated endovascularly in one center. Materials and Methods: Between 2007-2017 patients treated endovascularly at Hacettepe University Vascular Interventional Radiology Unit were included in the study. Patients who did not have CT / MRI images and could not follow up were not included in the study. Demographic characteristics, pre-procedural symptoms, clinical features and laboratory values of the patients were recorded. The types, number, internal structures, pre- and post-surgical dimensions of the lesions were analyzed. Embolization techniques and complication rates were calculated. The patients were divided into two groups using microparticles alone and microparticles and coils in combination. Recurrence and surgical intervention levels were recorded. Results: Totally 24 patients aged between 20-78 years (mean 45.4) underwent angiography. Twenty-seven lesions (32 procedures) with an average diameter of 7,3±2,5 cm were embolized. The duration of follow-up ranged from 6 to 120 months, with an average follow-up of 33.8 months. The technical success rate was 93.3% and the clinical success rate was 85%. Following embolization the average diameter decreased by 1.8 ± 0.83 cm (28.4±13,4 %). The average post-treatment size decrease was found to be statistically significant (p = 0.005). The renal function values (glomerular filtration rate and creatinine) of all patients before and after the procedure were measured at normal limits. Bleeding rate was higher in lesions with aneurysm greater than 5 mm. Recurrence rate was calculated at 15%. Major or minor complications were not observed. Two patients with persistent complaints underwent surgery (with their own will). There was no significant difference in recurrence and lesion shrinkage rates between groups using the microparticle alone and microparticle and coil combination (p = 0,207). Conclusion: Transarterial embolization is an effective treatment modality with low morbidity and mortality in AML lesions. In syndromic (Tuberous sclerosis) group of patients with multiple and complex lesions, embolization is convenient for the preservation of renal function. Coil embolization of the proximal arteries in AML lesions embolized with microparticles does not provide additional significant difference in the recurrence rate and lesion shrinkage. Keywords: Angiomyolipoma (AML), Tuberous sclerosis (TSC), Transarterial embolization.