Surgical Outcomes Of Syringomyelia With Craniocervical Junction Malformation: An Analysis Of 68 Cases

Objective: To study the clinical efficacy and imaging changes of surgical treatment of 68 cases of syringomyelia with craniocervical junction malformation,and to find out the causes of poor recovery of neurological function in patients with syringomyelia.Methods: Clinical data from 68 cases of syringomyelia with craniocervical junction malformation who met the inclusion and exclusion criteria from January 2019 to August2021 were collected and retrospectively analyzed.There were three main surgical methods:S1 including 39 cases underwent posterior fossa decompression,sharp separation of the adhesions and thickened arachnoid,cerebellar tonsillectomy and duraplasty.S2 including15 cases underwent posterior fossa decompression,sharp separation of the adhesions and thickened arachnoid,cerebellar tonsillectomy,duraplasty,syringosubarachnoid shunt using T-tube shunt.S3 including 14 cases posterior fossa decompression,occipitocervical fixation and fusion.The postoperative curative effect was evaluated by The Chicago Chiari Outcome Scale(CCOS).Evaluation of spinal cord function by modified Japanese Orthopaedic Association(m JOA)scores.The syrinx antero-posterior width,syrinx segment and tonsillar herniation were measured.Results: The results showed that 41 cases(60.29%)were improved,including 24 cases of S1 operation,7 cases of S2 operation and 10 cases of S3 operation.26 cases(38.24%)were stable,including 15 cases of S1 operation,7 cases of S2 operation and 4 cases of S3 operation.1 case(1.47%)deteriorated from S2 operation.CCOS pain score,non-pain score,function score,complication score and total score were lower after S2 operation.The changes of m JOA cervical vertebra score before and after operation were statistically significant.The spinal cord function recovery rates of patients with syringomyelia before and after operation were 66.67%,33.33% and 58.33% respectively.The score of spinal cord function of patients with syringomyelia in S2 was lower before and after operation.Compared with the images pre and post operation,the changes of the syrinx antero-posterior width and the syrinx segment of the three operations were statistically significant(P>0.05).The reduction rates of syrinx antero-posterior width were 31.86%,68.28% and 44.13%,respectively.The reduction rates of syrinx segment were 9.94%,33.44% and 14.17%,respectively.There was significant difference in the tonsillar herniation pre and post operation in S1 and S2(P<0.05),but there was no significant difference in S3(P>0.05).Conclusion: The three surgical methods all have good clinical effects.The therapeutic effect is related to the degree of cavity.The larger the syringomyelia,the more serious the compression of the spinal cord,the worse the recovery of related neurological defects,and even spinal cord atrophy and degeneration,resulting in irreversible damage of spinal cord function.Therefore,we suggest that patients with syringomyelia complicated with craniocervical junction malformation should be treated by operation as soon as possible after diagnosis.For each patient,individualized treatment should be made according to clinical symptoms and imaging findings.S1 operation is mostly used in patients with syringomyelia complicated with Chiari malformation type I,which can effectively reduce the syrinx and improve the symptoms.S2 operation is used in patients with Chiari malformation type I whose ratio of maximum diameter of syrinx to spinal cord diameter is more than 50%,which can significantly reduce the syrinx without recurrence.S3 operation is used in patients with syringomyelia complicated with bony malformation of craniocervical junction,which can improve clinical symptoms,reduce the syrinx and maintain the stability of craniocervical junction.