动物模型 z-bo 2020-08-10 520

　　(1) Replication method Rats were anesthetized by intraperitoneal injection with 30 mg/kg body weight of 1% barbiturate sodium, then the animals protruded on the spine stereotaxic instrument, fixed the skull and transverse processes on both sides of T11～L4, and performed a posterior median incision. , Expose T12～L3, and perform vertebral arch osteotomy (1～2 vertebral bodies, 3～4 lamina) from both sides of the level of T12～L3. Do not damage the spinal cord and nerve roots. Keep the dura mater intact. Observe the changes of the spinal cord from the excised upper and lower lamina, adjust the spine stereotaxic device to relax the spinal cord along the longitudinal axis of the spine, and gradually retract into the spinal canal to cause injury, shorten the spine at a speed of 2mm/30min, and use a vernier caliper and a stereotaxic device Determine the shortened distance.

　　(2) Model characteristics Before shortening the spine, stable spinal motor sensory evoked potentials (MEP, SEP) can be recorded. When the spine is shortened by 4 mm, there is no significant change in MEP. When the spine is shortened by 4 mm, the peak latency is extended by more than 10%, and the amplitude is reduced by more than 50%. , And 60% of the wave amplitude disappeared. At 8mm, only some traces of MEP remained, and 90% of the wave disappeared. The change trend of SEP is similar to that of MEP, but the degree is slightly lower; when shortened by 6mm, blood vessels dilate significantly, blood flow is slow, thrombosis can be seen, red blood cell aggregation is obvious, and bleeding around blood vessels presents congestion; during the shortening of the spine, the compression segment ( Both T13) and adjacent segment (L1) spinal cord gray matter blood flow decreased progressively. Observed by naked eyes, the shortened spinal cord showed a progressive longitudinal comb-shaped expansion, the spinal cord was loosened and horizontal folds appeared, and the spread was in the adjacent vertebral body, and it increased with the increase of compression. When shortened by 4mm, we can see a little spot-like oozing blood; when shortened by 6mm, there are multiple focal bleeding spots around the small capillary veins, more gray matter bleeding spots, fewer white matter bleeding spots, central canal deformation, and obvious bleeding, and the posterior spinal cord Focal hemorrhage is accompanied by rupture of the pia mater, severe hemorrhage and venous thrombosis, neuronal cells are eosinophilic with black basic nucleus cell bodies open, loss of staining ability is typical shadow cells, and nerve fibers have bubble-like changes. Axoplasmic fracture; when shortened by 8mm, extensive diffuse bleeding can be seen, and the structure is unclear.

　　(3) Comparative medicine According to the characteristics of the longitudinal movement of the spinal cord from the osteotomy to the spinal canal, the rat thoracolumbar segment was selected to simulate the vertebral arch vertebral osteotomy. When the spine is shortened and relaxed to a certain extent (about 6mm), the spinal cord at the osteotomy site will have neurological dysfunction, which spreads to the upper and lower vertebrae, and is mainly manifested by congestive ischemia. It is suggested that when multiple osteotomies are used clinically, each two should be adjacent to more than one vertebra, so that the function of the spinal cord is not affected by the adjacent osteotomies and the superimposed effect occurs. At the same time, it is pointed out that the shortening of the spine after osteotomy is limited, and it will cause irreversible damage if it is too large. It should not be used clinically to correct the angle of a large osteotomy, and appropriate osteotomy should be divided to improve the total osteotomy effect.