Reassessing the Role of the Subarcuate Artery in Hearing Preservation during Microvascular Decompression

The subarcuate artery, a branch of the anterior inferior cerebellar artery, has traditionally been considered a nonessential vessel whose sacrifice during cerebellopontine angle surgery is believed to produce no sequelae. Despite anatomical studies documenting the course and distribution of the subarcuate artery, no clinical reports have directly linked subarcuate artery injury to hearing impairment, reinforcing this traditional understanding. We retrospectively analyzed 3 cases of hearing impairment following subarcuate artery injury during microvascular decompression procedures, drawn from a series of 109 surgeries performed between January 2011 and December 2024 at our institution. All patients underwent continuous intraoperative auditory brainstem response monitoring, with detailed documentation of vascular events and corresponding signal changes. In all cases, intraoperative assessment confirmed that the labyrinthine artery remained intact, whereas the subarcuate artery was compromised. Each patient showed delayed auditory brainstem response deterioration, with complete signal loss occurring within 15-20 min after subarcuate artery manipulation. In 2 cases, deliberate transection or inadvertent avulsion of the subarcuate artery resulted in complete and permanent hearing loss. In the third case, a bleeding subarcuate artery was managed using compression hemostasis without coagulation, and serviceable hearing was preserved. To the best of our knowledge, this is the first clinical evidence that subarcuate artery injury can lead to hearing impairment, challenging the conventional understanding. The delayed auditory brainstem response deterioration pattern suggests that subarcuate artery injury affects inner ear perfusion through anastomotic connections with the labyrinthine artery, particularly in patients with anatomical variations. Therefore, we recommend preserving the subarcuate artery whenever possible to minimize the risk of postoperative hearing deficits.