经前路颈椎多节段椎管扩大术的实验研究及临床应用(附6例临床报告)

Experiment study of anterior enlargement of cervical spine canal and primary clinical application (with report of six cases)

目的设计颈椎前路椎管扩大术式并探讨该术式的可行性,为颈椎管的多节段狭窄的治疗提供一个新的手术方法。方法①标本实验:C1～T1尸体颈椎4个,在横突孔中穿入直径3mm橡胶管,注入造影剂。沿C4～6椎体前正中纵行劈开,横向撑开3～12mm,在CT下观察椎管,椎动脉及神经根管变化。②动物实验:成年绵羊4只,将C3,4纵向劈开,横向撑开9mm,取同侧胫骨骨块植入撑开区。术后观察其四肢运动恢复情况。③临床应用:对4例陈旧外伤性颈椎骨折伴完全性截瘫及2例多节段颈椎管狭窄伴不全截瘫患者行经颈椎管前路扩大术,观察手术效果。结果①椎体标本在撑开3mm、6mm、9mm后,椎管前后径平均增加1.14%、3.53%、5.15%,横径增加7.92%、14.62%、22.74%,截面积增加8.52%,17.99%,25.01%。两侧椎动脉走行间距平行,无折曲、受压。撑开前后神经根管各径及长度无变化。标本在撑开≤12mm时未见骨折,撑开>12mm时2例左侧,1例右侧椎板靠近棘突部骨折,均为裂纹骨折,无移位。4只绵羊术后第2d四肢可以自由行走,无神经、血管损伤征兆。②4例陈旧外伤性颈椎骨折伴完全性截瘫患者,术后截瘫未见恢复,但术后植骨愈合稳定,其中3例上肢感觉略有改善。2例多节段颈椎管狭窄伴不全截瘫患者术后3周截瘫完全恢复。结论①经前路颈椎体纵向劈开扩大术,可以增加椎管容积,由撑开所形成的骨间隙,对颈髓前方起到减压作用。②在撑开间隙内植骨,均获得骨性愈合。其优点是对脊柱三柱稳定不构成损害。③动物实验及初步临床应用表明:撑开间隙在一定范围内(≤9mm),对颈髓及周围组织均无损伤迹象。初步证明此术式具可行性及安全性。

Objective To study the feasibility of a new designed anterior enlargement of the cervical spine canal through vertebral body and provide a new method for the treatment of muhisegmental cervical spinal stenosis. Methods ① Specimen experiment： Four corps cervical spine were collected, The vertebral foramina were dissected and a latex pipe 3mm in diameter was inserted as the vertebral artery. The contrast agent was injected into the the pipe. The C4 to C6 vertebral bodies were split longitudinally along the midline to the posterior longitudinal ligament, and then the gap was separated to 3, 6, 9 and 12 mm, the spine canal, vertebral arteries and the neuroformen were observed on the CT scan. ② Animal experiment： Four adult sheep were used for animal experimental study. The C3 to C4 vertebra were split longitudinally through anterior approach and enlarged the gap to 9 mm under general anesthesia, and then the bone harvested from ipsilateral proximal tibia was grafted in place. The motion of the extremities was observed. ③ clinical application ： 4 old traumatic cervical spine fracture-dislocation with complete paralysis and 2 cases of muti-level cervical spondylosis with incomplete paralysis were treated with anterior enlargement of the cervical spine canal, clinical results were observed. Results When the gaps were separated to 3, 6, 9mm. the anterior-posterior diameter of the canal were increased by 1.14%, 3.53 % and 5.15%, the transverse diameter increased by 7.92%, 14.62% and 22.74%, and the section area increased by 8.52%, 17.99% and 25.10% respectively. The bilateral vertebral arteries run parallel without distortion and the diameter and length of the nerve root canal remain intact. There was no fracture found when the enlargement less than 9 mm . The fracture with minimal displacement were found in the left junction of the lamina and spinous process in 3 of 4 specimens when the gap was enlarged to 12 mm. Animal experiment demonstrated that the animal could move the extremities freely the day after the operation with no sign of nerve or blood vessel injury. The 4 cases of traumatic paralysis have no evidence of recovery but the bone graft were consolidate union after operation. The sensation of upper limbs of 3 cases were improved. The paralysis of 2 cases multi-level cervical spondylosis were complete recovered after 3 weeks of operation. Conclusion Anterior enlargement of the cervical spine canal can significantly increased volume as well as depress anterior part of the spinal cannel. Bone union can be obtained without damage to the three columns structure. Animals and clinical study showed there was no damage to spinal cord and surrounding tissues when the vertebral body was separated less than 9 mm. Therefore. The anterior enlargement of the canal is safe and practicable.