Basic Anatomy Of Occipital-vertebral Artery Anastomosis For Extracranial Vertebral Artery Stenosis

Objective:We used cadaveric head simulation to explore the route of revascularization for extracranial vertebral artery stenosis and the matching degree of V3 segment of vertebral artery and occipital artery bridging vessel,providing anatomical basis for clinical neurosurgical bypass surgery.Methods:This study intends to select 8(16 sides)cadaveric head specimens,adopt a v-shaped incision.This incision since ear on the mastoid 3 cm,going straight down along the sternocleidomastoid muscle fibers(SCMM),to the mastoid tip 2 cm below,then turning obliquely upward,finally,stopping at the external occipital protuberance level 4.5 cm outside.In turn,to cut off the SCMM and Splenius capitis muscle(SCM),and turn the muscle flap up,so we can anterograde the occipital artery(OA)with occipital artery sulcus for anatomical marks;This incision allows the suboccipital triangle to be simultaneously exposed.Cut off the lateral tendon of the obliquus capitis superior muscle(SOM),and turn this muscle upward.Carefully separate the suboccipital triangle,for exposing the third vertebral artery(V3).After fully exposed,measured the diameter of OA suboccipital segment and V3 segment,the effective free length of OA suboccipital segment,and the distance from the OA sulcus to the V3 sulcus(measured data are the average for 3 times),using EXCEL software to organize the measured data and designing W inspection,determine the Ⅱ error probability is P = 0.05.After statistics analysis,determining each group data obey the normal distribution with P > 0.05;The experimental results were described as mean ± standard deviation(X±S).Results:1.The incision since ear on the mastoid 3 cm,going straight down along the sternocleidomastoid muscle fibers(SCMM),to the mastoid tip 2 cm below,then turning obliquely upward,finally,stopping at the external occipital protuberance level 4.5 cm outside.In turn,to cut off the SCMM and Splenius capitis muscle(SCM),and turn the muscle flap up,so we can anterograde the occipital artery(OA)with occipital artery sulcus for anatomical marks;This incision allows the suboccipital triangle to be simultaneously exposed.Cut off the lateral tendon of the obliquus capitis superior muscle(SOM),and turn this muscle upward.This incision allows the suboccipital triangle to be simultaneously exposed.The lateral tendon of the SOM was dissected bluntly,and then the V3 sulcus segment was visible.2.The average diameter of OA suboccipital segment is(range:1.23±0.13-1.86±0.14)mm,the effective free length of OA suboccipital segment is(7.63±0.43)cm,the distance from the OA sulcus to the V3 sulcus is(1.47±0.11)cm,and that of V3 segment is(3.02±0.23)mm.Theoretically,the suboccipital segment of OA can provide sufficient blood flow for VA.Conclusion:1.The pillow to extracranial vertebral artery blood supply reconstruction,in order to reduce the wounds,shorten the operation time,we explore the design of a new "V" incision and the incision can be quickly and safely anterograde the suboccipital segment of OA,the surgical field more intuitive easy to operate,feasible on anatomy,the clinical application effect,still need a variety of means to further test and verify.2.The average diameter of OA suboccipital segment is(range:1.23±0.13-1.86±0.14)mm,the effective free length of OA suboccipital segment is(7.63±0.43)cm,the distance from the OA sulcus to the V3 sulcus is(1.47±0.11)cm,and the average diameter of V3 segment is(3.02±0.23)mm.Theoretically,the OA suboccipital segment can provide sufficient blood flow for V3 segment,providing theoretical support for the progress of revascularization from occipital artery to extracranial vertebral artery.