| ObjectiveMeeting the needs of the clinical application,the relevant anatomical studies were carried out by the approach of split laminectomy.We simulated this approach and performed operation on the specimen to clarify the maneuverability of split laminectomy.The deformation of lumbar vertebral via this approach was observed for discussing the safety of this operation.Further more,we measured related anatomic data and view Angle via this method and determine freedom of lumbar spine surgery by conducting experiments on a single vertebral unit to evaluate its effectiveness in the aspect of anatomy and provide guidance for clinical surgery.Finally,the study also discussed the advantages of the approach and explored the generalization related to the operation combine with the retrospective analysis of clinical cases.MethodsSection ?:1.Six adult cadaver specimens fixed with 10%formalin were selected.Firstly,the simulated surgical approach was performed on the specimens.the specimens were placed in prone position.the first and second lumbar segments were exposed to the roots and lamina of spinous process on one side(left side)of the first and second lumbar segments by positioning,incision and separation.A sutura was milled longitudinally along the roots of spinous process on one side(left side)with a milling cutter,which was about 2.0 mm wide and extended to the second lumbar spine.The fractures were gradually expanded to 0.6 cm,0.8 cm and 1.0 cm by a self-designed vertebral plate distractor.The anatomical structures which could be observed and operated under different distractor distances were recorded.When expanded to 10 mm,the spinal cord nerves were exposed and the dura mater was sutured by pulling and cutting the dura mater with corresponding instruments.After the operation is completed,loosen the vertebral plate distractor,close the operation cavity layer by layer,and record the operation flow;2.The adult cadaver specimens fixed with formalin were used to cut into lumbar vertebral segments and conduct in vitro experiments.Split-type vertebral plate cutting operation with different degrees is carried out on the selected lumbar segment respectively,the whole segment deformation is observed.Whether the upper and lower joint capsules of the expanded segment are damaged,whether the nerve root in the bilateral intervertebral foramen is subjected to bone clamping is also observed.Recording are carried out;3.The whole lumbar segment was cut into 5 vertebral body units for individual experiment.Plasticine and other tools were attached to the tissues around the vertebral body to simulate skin,fat,paravertebral muscles and other tissues.Split laminectomy was performed on a single vertebral body.The distraction distance was 0.8 cm(group A),1.0 cm(group B)and 1.2 cm(group C)respectively.Observe whether the vertebral body,lamina,pedicle and other structures are fractured during distraction.If there is fracture,record the fracture site and distraction distance(d)during distraction;4.The line of sight is simulated by using the kirschner wires,and the line of sight of the two kirschner wires and the line of sight positioning points of the spinal canal bottom wall are recorded under the conditions of positioning the spinal canal bottom wall from the left side to the right side and marking the intersection points of the two kirschner wires and the line of sight positioning points of the spinal canal bottom wall by using different colors.Measure the relevant numerical value.The cross angle of the kirschner wire under different distraction distances is obtained by the formula,which is the Effective angle that can be observed in practical operation.The data were analyzed statistically.Section ?:The clinical data of 10 patients with lumbar intraspinal canal tumor treated by split laminectomy in neurosurgery department of Northern Jiangsu People's Hospital were analyzed retrospectively.The time of operation,intraoperative bleeding and postoperative complications etc.were recorded.The advantages and generalization of this approach were discussed based on the anatomical study and literature review.ResultsSection ?:1.The first part:1.The whole body of adult cadavers fixed by 10%formalin was selected to carry out the simulated surgical approach experiment.The spinal dura mater and spinal canal structure could be clearly observed when the spinal cord was stretched to 10.0 mm,and the operations of dura mater pulling,incision,suture and spinal cord nerve stripping could be successfully performed.2.The lumbar segments were cut off from adult cadaver specimens and expanded in vitro.No obvious damage was found in the upper and lower articular capsules of the open side and the opposite side of the vertebral body,no obvious displacement was found in the upper and lower articular processes,and no bony compression was found in the nerve roots of the bilateral intervertebral foramen.3.The single experiment was carried out on each lumbar vertebra unit,and the vertebral plate was slowly and uniformly expanded by the vertebral plate expander.It was observed that the deformation mainly occurred in the the contralateral pedicle,The distraction distance(d)was(11.34±0.49)mm.4.Two kirschner needles were used to simulate the line of sight.The range of observation on Sipnal canal bottom wall from group A to group C is(10.64±0.89)mm?(13.44±0.36)mm?(17.76±0.76)mm in turn;According to the formula,the crossing angle of the kirschner wire from group A to group C is(26.11 ±2.10)°?(33.02±1.10)°?(44.27±1.99)°in turn.Section 2:The average time of unilateral operation was 239.5 min(150?335 min),intraoperative bleeding was 116 ml(50?200)ml,treatment improvement rate was 58%,postoperative bleeding,infection,intractable pain and other complications were not observed.After operation,the symptoms were improved in different degrees.ConclusionSection ?:Split laminectomy approach has the characteristics of direct approach,considerable operative field and Exact effect.Self-reset reduction of vertebral lamina was also a unique advantage of this approach.Mastery operation skills,fully understanding related anatomy and defining the safety range are the important prerequisites for ensuring the safety of operation.Section ?:Split laminectomy is a new approach for treating lumbar intraspinal canal tumors,which has the advantages of small tissue trauma,self-reset reduction,quick postoperative recovery,and fewer complications.It is suitable for clinical application. |
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