Transarterial embolization of renal arteriovenous malformations: treatment outcomes according to angiographic classification

Purpose To assess whether transarterial embolization using adjunctive techniques according to angioarchitectural types is effective for treating renal arteriovenous malformations (rAVMs). Materials and Methods Overall, 18 patients with rAVM (type 1, n=7; type 2, n=2; type 3, n=9; mean age: 53.8) who underwent 25 procedures, in total, between 2011 and 2022 were reviewed. The clinical characteristics, endovascular techniques, AVM occlusion rate, adverse events (including the incidence of renal infarction), and clinical outcomes (including recurrence/aggravation of AVM) and symptoms were analyzed according to the angioarchitectual types. Post-treatment renal infarction was classified as no infarction, small (<12.5%), medium (12.5–25%), and large infarction (>25%) using contrast-enhanced computed tomography or magnetic resonance imaging. Results Hematuria and heart failure were observed in 10 and 2 patients, respectively. The embolic materials used were as follows: type 1 AVM, coil alone or with n-butyl-2-cyanoacrylate (NBCA); type 2 AVM, NBCA alone or with coils; and type 3 AVMs, NBCA alone. Fourteen patients underwent adjunctive techniques, including flow control with a balloon catheter and multiple microcatheter techniques, alone or in combination. Immediate post-procedure angiography revealed complete occlusion in 15 patients (83%) and marked regression of AVM in 3. Small asymptomatic renal infarctions were observed in six patients with type 3 AVMs without any decrease in renal function. No major adverse events were observed. All symptomatic patients experienced symptom resolution. Recurrence/aggravation of AVM was not observed during the 32.4-month follow-up (2–120). Conclusions Transarterial embolization using adjunctive techniques according to angioarchitectural types can be an effective treatment for rAVMs.