A Microanatomic Study On The Anterior Communicating Artery Complex

As the development of the microneurosurgical techniques, more and more neurosurgeons have paid attention to the studies of the microsurgical anatomy. The anterior communicating artery complex (ACoAC) lies in the boundary of the anterior cranial fossa and the middle cranial fossa, because of its deep location and many vital structures involved, neurosurgeons have to master the anatomy, and the adjacent relationships of the ACoAC. This region can be the site of vascular, neoplastic, degenerative, congenital, or traumatological diseases. At present, the operative approaches in which related to this region and ACoA include subfrontal extraduaral approach, extensive subfrontal extraduaral approach, pterional approach and so on. We studied the microsurgical anatomy of this region concentrating on the Al segments of the anterior cerebral artery, the recurrent artery of Heubner ,the anterior communicating artery and it's branches. The relationship between their anatomical elements and their variation and their surrounding structures are discussed.Objective: To anatomise and measure ACoAC as well as its perforating branches under microscope, and expect to provide useful anatomic data for neurosurgeons.Methods: ACoAC and its perforating branches were dissected and measured under microscope in 15 formalin-fixed adult cadaver heads via trans-frontal approaches. The anatomical marks that are important to the surgical approach were investigated, for the purpose of obtaining some important anatomic parameters for neurosurgeons, guiding the procedures and avoiding severe complications as possible in the clinical operation. The distance between these landmarks were measured, and the adjacent structures, blood supplying and their variations were also recorded. The data were analyzed with SPSS 10.0 software.Results: The asymmetric caliber of bilateral Al segments of anterior cerebral artery (ACA) were found in 80% cadaver heads, while the number of their perforating branches between bilateral Al segments was no difference statistically (P>0.05) 83.87% of recurrent arteries of Heubner arose from the junction of ACA and ACoA or proximal A2 segment, while only 16.13% of their origin were at the distal Al segment near ACoA. 85.71% of ACoA anastomosed bilateral ACA simply by one channel, 86.67% of them were just over the optic chiasm. Branches were found in all of ACoAs. The little branches originated from any segment of the anterior communicating artery, but most of their sources tended to lie in the anterior cerebral atery in which had dominant blood flow, that is, left anterior cerebral artery in most cases. One ACA-A2 variation was found in this study, in which Left Al segment divided into a A2 segment, this single A2 segment supplied bilateral frontal lobes.Conclusions: The ACoACs have many variations in structure in native Chinese. Understanding the brain vascular anatomy sufficiently is helpful to improve the surgical outcome and reduce the severe complication as well.