远外侧入路中枕动脉的解剖特点及其在后循环搭桥手术中的意义

Anatomy of occipital artery through far lateral approach and its nuance in vessel bypass of posterior circulation

目的了解远外侧入路中枕动脉的解剖特点，为后循环搭桥手术提供解剖学依据。方法对血管注入染色乳胶的成人头颈标本10例（共20侧枕动脉）采用远外侧入路显微解剖开颅，观察枕动脉的起源、行程、邻近结构、血管分支，记录枕动脉各段的直径、可移植段的长度、椎动脉V3的直径以及与周围邻近结构的距离。结果枕动脉在下颌角水平起自颈外动脉的后壁，在颈外动脉内侧、颈静脉外侧上行，到达茎突后内侧区，转向后外侧行走，行于二腹肌后腹与头外侧直肌之间、二腹肌后腹与上斜肌之间，向内侧行走，在头长肌深面或表面行走．在上项线下方上斜肌、头半棘肌表面继续向内行走，经斜方肌、头半棘肌上项线附着点处穿出上项线上行，与枕大神经相伴，继续在头皮浅筋膜内上行，并分出1个或2个终末支，远端分布于头皮。枕动脉起点直径为f2．4±0．4）mm，寰椎横突上缘处的外径为（2．0±0．2）mm，越过上项线处的外径为（1．7±0．1）mm，寰椎横突上缘至越过上项线处的长度为（93．3±2．4）mm。枕动脉距枕外隆突的距离为（21．6±0．81mm。椎动脉V3段中点的直径为（3．3±1.3）mm。结论远外侧入路可以充分暴露枕动脉、椎动脉、寰枕交界区。以乳突尖、二腹肌后腹、寰椎横突为标志，能准确确定枕动脉位置，其直径和长度可满足后循环搭桥手术的需求。

Objective To observe the anatomical course of occipital artery through far lateral approach and make preparation for posterior circulation vascular bypass operation. Methods Far lateral approach was performed to observe the 20 occipital arteries in 10 cadaveric heads with color silicon glue perfusion. The origin, course branches, adjacent structure and diameter of related segments were observed and measured. The distance from the adjacent structures and the diameter of vertebral arteries were measured at the same time. The anatomical structures were recorded by taking photos. Results The occipital artery originated from posterior wall of external carotid artery at the level of mandibular angle and raised up between medial to external carotid artery and lateral to Jugular vein. Then it coursed to posteriorlateral direction, raising up between digastric posterior belly and rectus capitis lateralis, going up digastric posterior belly and superior oblique muscle. And then, it crossed longus scapitis on or beneath its surface and coursed medially on the surface of superior oblique muscle and semispinalis capitis muscle below the superior nuchal line. The occipital artery crossed up the superior nuchal line where trapezius muscle and semispinalis capitis muscle attached, accompanied with greater occipital nerve. And then, it outgrew 1 or 2 branches distributing the distal scalp beneath the superficial fascia of scalp. The diameter of occipital artery was （2.4±0.4） mm, （2.0±0.2） mm, （1.7±0.1） mm at the original point, superior border of transverse process and superior nuchal line, respectively. The length of occipital artery from point of superior border of transverse process to the point of superior nuchal line was （93.3±2.4） mm, from the point of superior nuchal line to external occipital protuberance was （21.6±0.8） mm. Diameter of the midpoint of V3 segment of vertebral artery was （3.3±1.3） mm. Conclusions The far lateral approach focusing on the vertebral artery could expose the course of occipital artery, vertebral artery, and atlas-occipital junction widely. The occipital artery could locate the position by mastoidale, digastric posterior belly, and transverse process of atlas. Its diameter and length are suitable for vessel bypass of posterior circulation.