Microsurgical Anatomy Of The Anterior Cerebeller Artery And The Superior Cerebellar Artery

ObjectiveTo study the microsurgery variation characteristics of the Anterior Cerebeller Artery (AICA) and the Superior Cerebellar Artery(SCA); make clear the neighbouring strucural relationships between the ACIA, the SCA, and the adjacent crinial bones and nerves, and their blood-supply as well; and therefore provide anatomical bases for relevant clinical operations in this area such as the cerebellar tumor operation, the microvarscular decompression and the intervention operation.MethodsThe AICA and the SCA of 40 formalin-fixed adult brain specimens (80 cerebral hemispheres) with intact dura mater were dissected under the surgical microscope. The length, diameter and number of these vessels were measured and counted; their shapes, courses, branches and connections were observed and recorded.ResultsThe diameter size of the AICA ranged between 0.48 and 2.32 mm (mean±standard deviation: 1.15±0.41 mm), and averagely 1.16 branches in each cerebral hemisphere were identified. 5.4 % of the total experimented ACIAs originated from the upper segment of the basilar artery (BA), 22.6 % from the middle segment, and 72 % from the lower segment. Approximately 64.5 % of these AICAs had inner and outer branches arising in the front of fasial nerve and acusticus nerve. The short stem type AICAs accounted for 7.5 %, and the long stem type 14 %. About 5.4 % of the AICAs were hypoplastic. The diameter size of the SCA ranged between 0.40 and 2.50 mm, with mean±standard deviation: 1.36±0.37 mm. 5.9 % of them originated from the posterior cerebral artery (PCA), one of which derived from the P2 segment. Totally 63 SCAs formed caudal loop, and 21 of them had a point of contacting with the trigeminal nerve, accounting for 33.3 %.ConclusionsSignificant microanatomical variations were found in the AICA and the SCA, which were closely related to the adjacent trigeminal nerve,fasial nerve and acusticus nerve. To improve the safety and reliability of surgeries in this area, it can be eminently helpful for neurosurgeons to have an intimate knowledge of microanatomy of the basilar vessels, and pay great attention to complex variations of the vessels.