Objectives: To study safety and efficacy of selective endovascular trans-arterial embolization (TAE) of renal angiomyolipoma (AML) in a 10-year period at a regional tertiary referral center in Denmark.

Patients and methods: All 56 patients who underwent TAE of renal AML at Departments of Urology and Radiology, Copenhagen University Hospital - Rigshospitalet, Denmark, from 2009 to 2020 were included. Seven without preoperative and postoperative imaging were excluded, leaving 49 patients for analysis. From national electronic medical records, we retrieved patient characteristics, surgical data, and follow-up data. Tumor size at the time of embolization and during follow-up was compared using Student's paired t test. Estimated glomerular filtration rate (eGFR) pre- and post-embolization were compared using Wilcoxon rank sum test.

Results: We included 49 patients of whom 4 had two tumors treated in the same TAE procedure. Median age was 50 years (interquartile range [IQR]: [29-67 years]), and the median follow-up time was 4.6 years [IQR: 3.0-6.7 years]. Post-embolization syndrome (PES) was experienced in 27 patients, and non-PES in 5 patients. Median length of hospital stay was 0 days [IQR, 0-1]. Postoperative Everolimus immunosuppressive treatment was offered to seven patients. Median tumor size was 6.0 cm [IQR: 4.6-7.9 cm] and was significantly reduced to 3.7 cm [IQR: 2.5-5.2 cm] after treatment (p < 0.001). Kidney function was not affected by TAE. Three deaths, not related to AML, were noted during follow-up.

Conclusion: Embolization of AML was in this cohort effective to significantly reduce tumor size without serious adverse events and loss of renal function. TAE is a safe and efficacious treatment and the preferred minimally invasive treatment option of AML.