Microsurgical anatomy of the atlantal part of the vertebral artery

BACKGROUND Microanatomy of the vertebral artery has been the subject of multiple studies. However, none of them has covered every aspect of microvascular anatomy of the atlantal part of the vertebral artery. MATERIALS AND METHODS Microsurgical anatomy of the atlantal part of the vertebral artery was studied in 14 cadaveric specimens. The artery was dissected using the standard microsurgical technique under operative microscope magnification. The atlantal part of the vertebral artery was divided into five segments: the foraminal, sagittal, transverse, medial condylar, and dural. The length of each segment was measured, as was the diameter of the artery. The branches of this part of the artery were identified and the distance between the point of dural entry of the artery and the midline of the atlanto-occipital dura was measured. Distance between the mastoid tip and the artery and the distance between the mastoid tip and the tip of C1 transverse process were measured. RESULTS Results of all measurements are summarized in tables and text. We discuss various anomalies, branches, and lesions of the vertebral artery and surgical approaches with new methods of managing diseases in this area.