CPT® Code 61684

An arteriovenous malformation (AVM) is a pathological condition characterized by an abnormal connection between the arterial and venous systems, where one or more arteries and veins connect directly without the intermediary of capillaries. This congenital malformation can lead to significant complications due to the high-pressure blood flow directly from arteries into veins, bypassing the normal capillary network. Intracranial AVMs can be classified based on their location within the brain, with infratentorial AVMs situated below the tentorium cerebelli, which separates the cerebellum and brainstem from the cerebrum. The infratentorial region includes critical structures such as the cerebellum, cerebellopontine angle, fourth ventricle, and brainstem. The surgical procedure coded as CPT® 61684 specifically addresses the surgical intervention for a simple infratentorial AVM. This procedure involves a craniotomy, where the scalp is incised to create flaps, burr holes are drilled into the skull, and a bone flap is elevated to access the dura mater. The AVM is then meticulously exposed, and using microsurgical techniques, the arterial feeders and draining veins are identified, ligated, and excised. The goal of the surgery is to completely remove the AVM to prevent potential complications such as hemorrhage, which can arise from the high-pressure blood flow associated with these malformations.