Microanatomy relation of carotid artery bifurcation with lateral branch of the superior laryngeal nerve / 中华神经医学杂志

ABSTRACT

Objective To discuss the microsurgical anatomy of carotid bifurcation and external branch of the superior laryngeal nerve (EBSLN),and to explore the operative techniques in carotid endarterectomy.Methods The carotid bifurcation (20 sides) of 10 cadaveric heads was studied by using microanatomy from January 2017 to January 2018.The distance between bifurcation of carotid artery to peripheral bone structure,and the distances between point of EBSLN to medial margin of the carotid artery to mandibular angle,most prominent point of the larynx,apex of the mastoid,and bifurcation of carotid artery were measured.Results (1) The vertical distance from carotid bifurcation to larynx point and mandibular angle was 24.32 (18.8-35.78) mm and 13.55 (9.26-19.60) mm.The straight distance from carotid bifurcation to mastoid tip was 68.59 (49.48-76.94) ram.According to the vertical distance of larynx point to carotid bifurcation,the height of bifurcation of the carotid artery was consistent with the results of wain measurement (K=0.90),and the difference was statistically significant (P＜0.05).(2) The distances between the point of EBSLN to medial margin of the carotid artery to carotid artery bifurcation,upper thyroid artery bifurcation,mandibular angle and mastoid process were 17.81 (15.24-25.58) mm,19.42 (17.08-29.12) mm,20.51 (17.98-22.20) mm,71.00 (69.00-74.50) mm in normal bifurcations.Those in the high bifurcation specimens were 6.40 (2.44-9.20) mm,8.84(4.74-10.88) mm,12.15(10.64-13.54),60.90 (59.80-66.50) mm,respectively.Conclusions The position of the laryngeal prominence is fixed,which can be used as a marker for surgical incision.When the vertical distance from the larynx point to the bifurcation of the carotid artery is greater than or equal to 2.5 cm,it is highly bifurcated;the bifurcation is normal when less than 2.5 cm.In patients with normal carotid bifurcation,1.5 cm of the carotid artery bifurcation can be used as a safety mark limit during the operation.For patients with high carotid artery,the EBSLN is almost parallel to or down the superior thyroid artery,and it should be closely attached to the bifurcation of the carotid artery and the outer membrane of the superior thyroid artery,and there is no safety margin.