Microarteriovenous Fistulas Causing Refractory Skin Ulcers: Feasibility and Safety of Transcatheter Embolization.

PURPOSE: Microarteriovenous fistulas (m-AVFs) have been proposed as a potential cause of lower limb ulcers that are refractory to standard therapies. This study evaluated the feasibility and safety of transcatheter arterial embolization (TAE) using imipenem/cilastatin sodium (IPM/CS) in patients with m-AVF-related refractory skin ulcers. METHODS: This retrospective study included 17 patients with lower limb refractory skin ulcers treated with TAE from 2013 to 2023. M-AVFs were diagnosed via Doppler and confirmed by angiography. Embolizations were done under local anesthesia through femoral artery access, using imipenem/cilastatin mixed with contrast, injected until flow stagnation or a 0.5 g max. Technical success was defined as the elimination of early venous shunting on angiography. Clinical success was defined as a ≥ 50% reduction in ulcer size. Repeated TAE procedures were performed at 1-2-month intervals when clinical improvement was deemed insufficient, primarily based on physician judgment regarding ulcer size and pain. While no strict quantitative threshold was used, the decision to proceed with additional sessions beyond three was based on discussion between the patient and physician. The outcome evaluation included assessments of ulceration and pain severity. RESULTS: We performed 41 embolizations on 17 patients, with repeat sessions every 1-2 months if needed. Technical success was achieved in all cases (100%). No major complications occurred; minor pain was reported in ~ 20% of cases. Over an average 11.5-month follow-up, clinical success was observed in 88% of patients. CONCLUSION: TAE with IPM/CS is a feasible and safe treatment option for refractory lower limb skin ulcers caused by m-AVFs.