Safety Analysis Of Anterior Percutaneous Endoscopic Cervical Discectomy

Objectives:This study aims to guide the application of anterior cervical spine surgery and to decrease the injury of vital tissues and organs by measuring and analyzing the safety angle and security distance based on the signal of cervical MRI collecting from the outpatients.Methods:The patients(2015-2016) were settled into 4 groups according to the age into 4 groups. Each group includes equal numbers(20 persons) of men and women. The axial view of cervical MRI in the sections of C3-4,C4-5,C5-6 and C6-7 is analyzed. For convenience, we set the point which quadrisect the front edge of the cervical intervertebral disc as a reference point. Percutaneous puncture should be divided into two parts. The first step starts from the surface of skin to the anterior edge of intervertebral disc. The tangents of the esophagus and carotid artery in terms of the reference point and the midperpendicular of the maximum transverse diameters of the intervertebral disc were drew. Then, we recorded the points of intersection of two tangents and the edge of the skin and then calculated the angles of the two tangents and the midperpendicular. Meanwhile, the distances between the intersection points and the midperpendicular were measured. The second step begins from the anterior of the intervertebral disc to the operative region. The tangents of the spinal cord and the vertebral artery along the same reference point were mentioned above. We recorded the point of tangency, calculated the angles between the two tangents and the midperpendicular and measured the distance between the reference points and the pointcuts. The statistics analysis was conducted using SPSS21.0.Results:The maximum angle between the tangent of carotid artery and the midperpendicular is 72.08 degree occuring in C3-4 segment with the age of 46-55, female. The minimum angle is 46.96 degree which lies in C6-7 segment with the age of 26-35, female. The maximum angle between the tangent of pharynx or esophagus and the midperpendicular is 40.14 degree which appears in C5-6 segment with the age of 56 to 65, male. Meanwhile, the minimum angle is 18.11 degree which lies in C6-7 segment with the age of 56 to 65, male. The maximum angle between the tangent of vertebral artery and the midperpendicular is 73.11 degree which lies in C6-7 segment with the age of 46 to 55, male,meanwhile, the minimum angle is 59.93 degree which lies in C3-4 segment with the age of 56 to 65, female. The maximum angle between the tangent of spinal cord and the midperpendicular is 38.50 degree which lies in C3-4 segment with the age of 46 to 55, female,meanwhile, the minimum angle is 30.99 degree which lies in C5-6 segment with the age of 56 to 65, female.Conclusions:The anatomy of the cervical region is very complex and the surgeon should master the applied anatomy knowledge of anterior cervial approach and have the rich clinical experience of the three-dimensional framework.Before performing the anterior approach endoscopic cervical discectomy, the surgeon should make a sufficient preoperative design of the patient individually.