Abstract:

Objective　To evaluate the feasibility of lower cervical transforaminal endoscopic surgery by lateral approach.　Methods　Applied anatomy in 40 sides of 20 adult cadavers were performed. Vertical incision at C3~7 levels along posterior margin of stenomastoid was performed through anterior or posterior space of brachial plexus (ASBP or PSBP) for lateral approach to target vertebra. Subsequently, dissection and anatomic measurement of important structures were carried out in mimic surgery.　Results　 (1) According to the lengths, root angles and root intervals of C5 to C8 nerve roots, sufficient exposure of these nerve roots was proved in transforaminal endoscopic surgery via anterior or posterior space of brachial plexus. (2) According to the distances between phrenic nerve (PN) and anterior tubercles of transverse processes (ATTP) of C4 to C6 vertebrae, PN was invulnerable in surgery through PSBP. (3) According to the distances between cervical sympathetic trunk (ST) and ATTPs of C3 to C7 vertebrae, lower risk in cervical ST injury was revealed in surgery via PSBP than that via ASBP.  (4) Thoracic duct (TD) ran into venous angle between C7 and T1 vertebra levels in 70% cases, and lower risk in TD injury was revealed in surgery via PSBP than that via ASBP. (5) Vertebral artery (VA) was distracted laterally by (2.5±0.4)cm at C7 vertebral level in mimic surgeries. Thus VA protection should be concerned in surgery both via ASBP and PSBP. (6) The distance between cervical pleura and C7 vertebral transverse process tip was (1.9±0.4)cm. Cervical pleura injury was observed in surgery via ASBP or PSBP.　Conclusions　Safe lateral approach through PSBP is proved for lower cervical transforaminal endoscopic surgery.

Key words: Lateral approach, Posterior space of brachial plexus, Transforaminal endoscopy, Applied anatomy