Applied Anatomy And Clinical Study Of Minimally Invasive Spinal Endoscopic Technique In The Treatment Of The Thoracic Disc Herniation

Objective: Percutaneous endoscopy thoracic discectomy(PETD)is a minimally invasive spinal surgery.However,due to the large anatomical differences between thoracic vertebrae and lumbar vertebrae,the storage space of thoracic spinal canal is very limited,and the anatomy of thoracic intervertebral foramen region is very complex.The spinal cord has relatively poor tolerance,and is affected by rib and thoracic cavity,so the space of operation is limited.The adjacent spinal cord,blood vessel or spinal nerve are damaged in the limited operating space during the operation.Therefore,there are few reports on the treatment of thoracic disc herniation by percutaneous foramen technique at home and abroad.This research will be aimed at the region of intervertebral foramen of thoracic vertebrae.To investigate the feasibility and effect of the technique in the treatment of thoracic disc herniation.Methods: 12 formalin immersion cadavers(6 males and 6 females)were selected as adult specimens.There were no other pathological conditions affecting the anatomy of thoracic vertebrae and a set of anatomical instruments.The CT MRI data of thoracic vertebrae of 30 adult patients with nonthoracic vertebra lesions in our hospital in recent 5 years were collected,including 15 male and 15 female patients aged 15-65 years.The data were scanned by 640 T CT scan and 1.5T MRI scan.At the same time,the vessels were displayed by CTA,and the anatomical structure of thoracic vertebrae was reconstructed by three-dimensional(3-D)technology.The original imaging data were preserved for DICOM format.Bone,nerve and blood vessels were reconstructed by MIMICS 16.0 software.The transverse diameter of intervertebral foramen of the thoracic disc plane were measured.The maximum diameter of the intervertebral foramen and the distance from the external orifice to the median line of the interforaminal foramen of the thoracic vertebrae were measured too.Results: The average horizontal transverse diameter of the intervertebral foramen was(9.7±1.6)mm,n=30,and the data of horizontal transverse diameter of the intervertebral foramen showed F=22.78,P < 0.01,and there was a statistical difference.It showed that the horizontal transverse diameter of the intervertebral foramen was not exactly the same;the mean diameter of the thoracic vertebral intervertebral foramen was(9.9±1.4)mm,n= 30,the data of the maximum diameter of the thoracic vertebral foramen showed F=23.57,P < 0.01,with statistical difference,indicating that the maximum diameter of the vertebral foramen was not exactly the same.Both in the level of the intervertebral foramen in the thoracic vertebra,or on the maximum diameter of the vertebral foramen,the mean value of both can be larger than the transverse diameter of the intervertebral foramen mirror,and can be successfully placed in the thoracic vertebra foramen area to perform the related operation.The mean distance between the external foramen and the median line of thoracic vertebra was(17.3 ± 4.6)mm,n=30.With this data,we can help judge the distance between the puncture points and the median line.The spinal intervertebral foramen contains the following main components: the spinal nerve and the nerve root,the segmental artery,the intraspinal venous plexus and the root vein,the thoracic vertebra foramen ligament,the shape of the thoracic vertebra and so on.Their adjacent anatomical structures are detailed in the body diagram.The anatomical features show the nerve root of the thoracic vertebra,the root vessel and the sinus vertebrae.It is located in the upper part of the foramen,and the lower part of the intervertebral foramen provides a potential operation space for the insertion of the spinal endoscopy,making it possible to apply the spinal endoscope to the thoracic vertebra.However,the lower wall of the intervertebral foramen often has an intervertebral vein,which should be avoided during the operation.Based on the results of the study,5cases of thoracic disc herniation were successfully performed by endoscopic surgery,and a standardized procedure was developed.Conclusion: The results of the study and clinical application show that the minimally invasive technique of the spinal endoscopy(intervertebral foraminoscopy)is feasible for the treatment of thoracic disc herniation.The accurate measurement of the related data of the thoracic vertebra on the imaging data and a scientific operation plan can improve the safety of the operation and achieve a satisfactory surgical effect.This study can provide a new,minimally invasive and reliable treatment for surgical treatment of thoracic disc herniation.