Endoscopic Anterior Approach To Upper Cervical Vertebra Applied Anatomic Study

Objective: The purpose of the cadaveric study was to determinate the safety,usefulness and convenience of Endoscopic anterior cervical surgery to upper cervical vertebra by evaluating available space for guide tube,the relationship between guide tube and surrounding structure,inserted angle of guide tube,the cervical sympathetic chain distances between right side and right side whether it is affordable for guide tube.The conclusion would be to support clinical application of the technique.Methods: three embalmed adult cadavers came from Anatomic department of Medicine university of Guangxi.After inserting guide tube,gradual dissection was performed.Then evaluating the space for tube,measuring the vertical distances between the posterolateral rim of thyroid cartilage and upper thyroid artery,assessing the relation between guide tube and surrounding structure,ascertaining distances of the right and left cervical sympathetic chain at C1~C2,finding out the angle consisting of cervical sympathetic chain and anterior axial line,observing anatomic shape of longus colli and longus capitis were done.Results: 1.All cadaver were inserted successfully with tube system;2.The transverse incision was located in C4~C5 medially to sternocleidomastoid,below the posterolateral rim of thyroid cartilage.The space between upper thyroid artery and common carotid artery was enough to get 18 mm tube in.The origin of upper thyroid artery was above the posterolateral rim of thyroid cartilage;3.When it was in-depth,there were a assuming gate consisting of the esophagus and trachea medially,and the sternocleidomastoid muscle and carotid sheath and its contents laterally,upper thyroid artery above.The vertical distances between the posterolateral rim of thyroid cartilage and upper thyroid artery is(6.54±1.04)mm.At the time,the tube traversed below upper thyroid artery vessel;4.In retropharyngeal space,there were the esophagus and trachea anteriorly,prevertebral fascia posteriorly.At C1~C2 level,guide tube getting inside the space,the tube was separated from surface vessels and nerves by laryngopharynx.At the time,the tube attached to posterior pharyngeal;5.Both cervical sympathetic chains were located in posterior part of retropharyngeal space,distributing both side of vertebra,covered by muscle fascia of longus colli,with a “v”shape.The distances of right and left side were(49.22±1.99)mm.The angle consisting of cervical sympathetic chain and anterior axial line is(11.33゜±1.41゜).In front of cervical vertebra,anterior longitudinal ligament integrate with muscle fascia.At the moment,guide tube was in the place of anterior longitudinal ligament,whole tube obliquely traversing cervical sympathetic chains,with carotid sheath and its contents laterally,the esophagus and trachea medially.Conclusion(s): Endoscopic anterior cervical surgery to upper cervical vertebra using guide is relative security,usefulness,convenience.