Middle Meningeal Artery to Premeatal Anterior Inferior Cerebellar Artery Bypass Via Anterior Petrosectomy: An Anatomic Feasibility Study.

INTRODUCTION: Anterior-inferior cerebellar artery (AICA) aneurysms are rare with no optimal consensus on management strategies. When the treatment requires parent artery occlusion post-operative ischemic or neuropathic, complications can occur.

OBJECTIVE: To evaluate the feasibility of direct revascularization of premeatal AICA using the middle meningeal artery (MMA) as the donor through an anterior petrosectomy (APA) window.

METHODS: Ten specimens were used for the surgical simulation of the MMA-AICA bypass. The MMA was harvested from the dura down to the foramen spinosum (FS). An APA was performed on each specimen and the AICA was exposed up to its origin from the basilar artery. The lateral pontine (a2) segment was mobilized laterally and the end-to-end anastomosis was completed. Measurements of the required length of the AICA, MMA and their calibers at the anastomotic site were recorded.

RESULTS: The MMA-AICA bypass was feasible in all the specimens. The mean length of AICA from the origin at the anastomotic site was 7.3±1.7 mm, with the mean length of MMA from FS being 34.6±5.1 mm. The mean calibers of the MMA were 2.1±0.2 mm at FS and 1.7±0.2 mm at the anastomosis. The a2 caliber was 1.6±0.3 mm with an average lateral mobilization of 7.6±2.7mm.

CONCLUSION: Our study establishes the feasibility of an MMA-AICA bypass via a middle fossa approach. The matching caliber of the two arteries makes the end-to-end anastomosis easy to achieve. The MMA is a suitable donor artery that avoids the use of interposition graft and the complications of an extracranial-intracranial bypass.