Efficacy Of Minimally Invasive Posterior Fossa Decompression Treatment For Chiari Ⅰ Malformation Combined With Syringomyelia

Objective.To summarize the advantages and disadvantages of the modified procedure and to discuss it’s clinical value by reviewing the clinical data and literature on patients who suffered ChiariⅠ malformation combined with syringomyelia.Materials and Methods.Clinical data of 54 patients with ChiariⅠ malformation combined with syringomyelia treated surgically at the China-Japan union Hospital of Jilin University from January 2017 to February 2022 were selected for retrospective analysis.The patients were divided into other surgery group and modified surgery group according to the surgery performed,and the improvement rates of various symptoms in both patients before and after surgery were analyzed to evaluate the effectiveness of the modified surgery for the treatment of ChiariⅠ malformation combined with syringomyelia.Results.Ⅰ.At the time of discharge,the number of effective cases in the other operation group was 19,and the number of ineffective cases was 3,with an effective rate of50.00%;the number of improved cases in the modified operation group was 11,and the number of ineffective cases was 1,with an effective rate of 68.75%,and the difference was not statistically significant（P=0.243>0.05）;the number of effective cases in the other operation group was 20,and the number of ineffective cases was 18,with an effective rate of 52.63%;the number of improved cases in the modified operation group was 11,and the number of ineffective cases was 1,with an effective rate of 68.75%.At3 months after surgery,the number of effective cases in the other surgery group was 20,and the number of ineffective cases was 18,with an effective rate of 52.63%.The difference was statistically significant（P=0.029<0.05）;at 6 months after surgery,the number of effective cases was 20 and ineffective cases was 18 in the other surgery group at 6 months after surgery,with an effective rate of 52.63%;at 3 months after surgery,the number of effective cases was 15 and ineffective cases was 1 in the modified surgery group,with an effective rate of 93.75%.The difference was statistically significant（P=0.243<0.05）.Ⅱ.Electromyography results of the extremities.Other operation groups: there were 16 patients with abnormal sensory nerve conduction,10 patients with abnormal motor nerve conduction,6 patients with abnormal F wave and 3 patients with abnormal H-reflex in 20 patients with preoperative extremity electromyography.There were 3 cases of partial remission and 0 cases of complete remission in the postoperative patients with abnormal sensory nerve conduction in the extremities,2 cases of partial remission and 0 cases of complete remission in the postoperative patients with abnormal motor nerve conduction in the extremities,0 cases of complete remission in the postoperative F waves,and 0 cases of partial remission in the postoperative H reflex.In the modified procedure group,there were 8 patients with abnormal sensory nerve conduction,5 patients with abnormal motor nerve conduction,2 patients with abnormal F waves,and 1 patient with abnormal H reflex in the 13 patients who had preoperative electrographic examination of extremities.Postoperatively,there were 4 cases of partial remission and 1 case of complete remission of sensory nerve conduction abnormalities in the extremities,1 case of partial remission and 0 case of complete remission of motor nerve conduction abnormalities in the extremities,1 case of complete remission of F waves after surgery,and 0 case of partial remission of H reflex after surgery.The improvement rate of preoperative and postoperative nerve conduction abnormalities Fisher value=0.021<0.05,the difference was statistically significant;the improvement rate of preoperative and postoperative motor nerve conduction abnormalities compared with Fisher value=0.013<0.05,the difference was statistically significant;the improvement rate of preoperative and postoperative F wave abnormalities compared with Fisher value=0.002 < 0.05,the difference was statistically significant;preoperative Postoperative H-reflex improvement rate compared to Fisher value = 0.222 > 0.05 the difference was not statistically significant.Conclusion.This study shows that the modified procedure is an effective procedure for the treatment of Chiari Ⅰ malformation combined with syringomyelia,and its long-term efficacy（6 months post-operative）is especially significant compared with other traditional procedures.