经颞下入路对基底动脉顶端区域显微解剖研究

The microsurgical anatomy study of basilar artery apex via subtemporal approach

目的通过尸头标本模拟颞下入路观察基底动脉分叉部显露范围,为临床基底动脉(BA)顶端区域病变手术入路提供参考依据。方法 10具(20侧)成人尸头标本,显微镜下模拟颞下入路解剖观察基底动脉顶端区域主要神经血管结构之间的关系,明确到达基底动脉分叉部所暴露的视野范围。结果颞下入路颧弓(颧弓后根前1/3处的颅骨内板)至小脑幕游离缘的最短距离为39.24±1.27mm,发现滑车神经自后床突后外方15.72±3.81mm处穿入小脑幕游离缘,在幕中潜行6.82±1.81mm,在未切开小脑幕游离缘之前,可暴露中颅窝底,斜坡面可暴露后床突鞍背及基底动脉分叉部、大脑后动脉的后穿支动脉;切开部分小脑幕游离缘增加向下的暴露,可见基底动脉分叉部及其主要分支,并扩大了对脑桥中部外侧面的视野。结论颞下入路可从侧方直视下观察基底动脉分叉部及P1段后方穿支动脉,利于对于动脉瘤顶部指向后和后下方动脉瘤的处理。在后床突后外方17mm以后切开小脑幕,是避免滑车神经损伤较为安全的方法。打开小脑幕后,增加了BA向下的暴露并扩大了对脑桥中部外侧面的视野。

Objective To explore the scope of the bifurcation of basilar artery （BA） via subtemporal approach, and provide reference for the microsurgery of BA apex lesion. Methods Ten （ 20 sides） adult cadaveric specimens which perfused with colored silicone were studied by using suhtemporal approach under the microscope, We observed and measured the relationship among the important neurovascular structures and described the exposure scope of the bifurcation of basilar artery. Results The shortest distances from the zygomatic arch to the edge of tentorium incisura was 39.24 ±1.27mm. We found that the trochlear nerve entered the edge of tentorium in post- lateral PCP. The mean distance was 15.72± 3.81ram. The subtemporal approach could provide wide exposure for the base of the middle cranial fassa and perforating arteries arising from BA bifurcation and P1 segment. Conclusion The subtemporal approach has advantages such as shorter distance of operation, bigger straight visual angle. We can observe the perforating branches arising from BA bifurcation and P1 segment though lateral wider visual field, when clipping the aneurysm which directed backward. Cutting the tentorium at the post-lateral 17mm point away from PCP can avoid damaging the trochlear nerve. The exposure of the BA apex can be increased after cutting tentorium, and a wider scope of expoure is obtained to the lateral aspect of the brainstem.