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

BACKGROUND

Anterior inferior cerebellar artery (AICA) aneurysms are rare with no optimal consensus on management strategies. When treatment requires parent artery occlusion, postoperative ischemic or neuropathic complications can occur. This study evaluated the feasibility of direct revascularization of premeatal AICA using the middle meningeal artery (MMA) as the donor through an anterior petrosectomy window.

METHODS

Ten specimens were used for surgical simulation of MMA-AICA bypass. MMA was harvested from the dura down to the foramen spinosum. An anterior petrosectomy approach was performed on each specimen, and 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

MMA-AICA bypass was feasible in all specimens. The mean length of AICA from the origin at the anastomotic site was 7.3 ± 1.7 mm, and mean length of MMA from the foramen spinosum was 34.6 ± 5.1 mm. Mean calibers of MMA were 2.1 ± 0.2 mm at the foramen spinosum and 1.7 ± 0.2 mm at the anastomosis. A2 caliber was 1.6 ± 0.3 mm with average lateral mobilization of 7.6 ± 2.7 mm.

CONCLUSIONS

This study establishes the feasibility of MMA-AICA bypass via a middle fossa approach. The matching caliber of the 2 arteries makes end-to-end anastomosis easy to achieve. The MMA is a suitable donor artery that avoids the use of an interposition graft and the complications of extracranial-intracranial bypass.