Microsurgical Anatomy of the Labyrinthine Artery and Clinical Relevance.

ABSTRACT

AIM: To describe the origin, the course, and relationships of the labyrinthine artery (LA). MATERIAL AND METHODS: Thanks to a colored silicone mix preparation, ten cranial bases were examined using x3 to x40 magnification under surgical microscope. RESULTS: The LA often arose from the meatal loop of the anterior inferior cerebellar artery (AICA) (90%), or basilar artery (10%). The loop was extra-meatal of the internal auditory meatus (IAM) in 30%, at the opening of the internal auditory meatus in 20%, or intra-meatal in 35%. The AICA coursed in closed relationship to the VII and VIII cranial nerves. It coursed between VII and VIII cranial nerve roots in 85%, or passed over the ventral side of both VII and VIII cranial nerve. The average diameter of the LA was 0.2 +/- 0.05 mm. LA was single trunk in 60%, and bi-arterial in 40%. CONCLUSION: The implication of these anatomic findings for cerebello-pontine angle tumors surgery and neurovascular pathology such as infarction, aneurysm of the LA or the AICA are reviewed and discussed.