A Combinatorial Approach with Cerebellar Tonsil Suspension to Treating Symptomatic Chiari Malformation Type I in Adults: A Retrospective Study

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Patients With Chiari Malformation: Surgical Interventions

BACKGROUND

Chiari malformation type I (CIM) diagnoses have increased in recent years. Controversy regarding the best operative management prompted a review of the literature to offer guidance on surgical interventions.

OBJECTIVE

To assess the literature to determine (1) whether posterior fossa decompression or posterior fossa decompression with duraplasty is more effective in preoperative symptom resolution; (2) whether there is benefit from cerebellar tonsillar resection/reduction; (3) the role of intraoperative neuromonitoring; (4) in patients with a syrinx, how long should a syrinx be observed for improvement before additional surgery is performed; and 5) what is the optimal duration of follow-up care after preoperative symptom resolution.

METHODS

A systematic review was performed using the National Library of Medicine/PubMed and Embase databases for studies on CIM in children and adults. The most appropriate surgical interventions, the use of neuromonitoring, and clinical improvement during follow-up were reviewed for studies published between 1946 and January 23, 2021.

RESULTS

A total of 80 studies met inclusion criteria. Posterior fossa decompression with or without duraplasty or cerebellar tonsil reduction all appeared to show some benefit for symptom relief and syrinx reduction. There was insufficient evidence to determine whether duraplasty or cerebellar tonsil reduction was needed for specific patient groups. There was no strong correlation between symptom relief and syringomyelia resolution. Many surgeons follow patients for 6-12 months before considering reoperation for persistent syringomyelia. No benefit or harm was seen with the use of neuromonitoring.

CONCLUSION

This evidence-based clinical guidelines for the treatment of CIM provide 1 Class II and 4 Class III recommendations. In patients with CIM with or without syringomyelia, treatment options include bone decompression with or without duraplasty or cerebellar tonsil reduction. Improved syrinx resolution may potentially be seen with dural patch grafting. Symptom resolution and syrinx resolution did not correlate directly. Reoperation for a persistent syrinx was potentially beneficial if the syrinx had not improved 6 to 12 months after the initial operation. The full guidelines can be seen online at https://www.cns.org/guidelines/browse-guidelines-detail/3-surgical-interventions .

Pain and Depression Account for More Than One Half of the Neck Disability Variance Among Adult Women with Chiari I

OBJECTIVE

We sought to quantify the neck-related disability in adult women with Chiari malformation type I and identify the significantly related variables.

METHODS

A total of 70 variables were selected from the self-report history questionnaires (12 variables; n = 474), standardized scales (15 variables; n = 474), and morphometric data (43 variables; n = 293-474) of adult women with Chiari malformation type I. The variables were tested independently to identify those with a significant relationship to the Neck Disability Index (NDI; P < 0.00071) and those that might be associated with the NDI (P < 0.05). A forward selection regression model was constructed to identify the variables contributing unique variance to the NDI. In addition, a mediation analysis was performed to determine whether depression mediated the relationship between pain and disability.

RESULTS

Overall, 79.5% of the patients had scored at a moderate level of disability or higher. Independent testing identified 16 significant variables, including symptom duration, tonsillar position, and measures of psychological distress. The short-form McGill pain questionnaire-2 (r = 0.69; P < 0.00001) and CES-D scale for depression (r = 0.56; P < 0.00001) exhibited the highest correlations with the NDI. The forward selection regression model produced an R2 of 0.6178. Pain and depression accounted for more than one half of the NDI variance.

CONCLUSIONS

We found that high levels of disability are common among adult women with Chiari malformation type I, independent of surgical status. Pain and depression were the primary factors related to this disability. Depression mediated the relationship between pain intensity and disability at a modest level (5%). Patients who had experienced symptoms for >2 years before diagnosis had had, on average, 77% higher NDI scores, highlighting the importance of a timely diagnosis.

Outcome evaluation of decompression surgery combined with cerebellar tonsillectomy compared without cerebellar tonsillectomy for Chiari type I malformation patients

BACKGROUND

Surgical intervention is an important treatment option to improve the prognosis for Chiari type I malformation (CM-I) patients. However, there is no consensus about surgical strategies. The article intends to evaluate the effect of decompression combined with or without cerebellar tonsillectomy in the treatment of CM-I.

METHOD

Following PRISMA's principles, Embase, PubMed, Web of Science, and Cochrane databases and references to relevant articles were searched to include only original articles on decompression combined with or without cerebellar tonsillectomy in CM-I patients. Through meta-analysis, the data on clinical improvement, radiological improvement, and complications were pooled.

RESULTS

Nine articles, including 399 CM-I patients undergoing decompression alone and 343 undergoing decompression with cerebellar tonsillectomy, meet the inclusion standard. In comparison, the improvement rate of clinical symptoms or signs in patients with cerebellar tonsillectomy is higher and statistically significant (RR: 0.85, 95% CI: 0.75-0.95; P = 0.006). However, decompression with cerebellar tonsillectomy is also significantly higher in the incidence of postoperative complications (RR: 0.54, 95% CI: 0.36-0.80; P = 0.002). No statistical difference is discovered between the two groups in the improvement rate of syringomyelia (RR: 0.77, 95% CI: 0.57-1.03; P = 0.08).

CONCLUSIONS

Although decompression with cerebellar tonsillectomy is superior than decompression alone in clinical improvement for CM-I patients, it also faces a higher risk of postoperative complications. The reduction of syringomyelia in the two groups can be considered equally effective without significant differences. In the future, the results of the research require multicenter and large-scale randomized controlled trials to verify in clinical practice.

TRIAL REGISTRATION

CRD42022321750 (PROSPERO).

Comparative Assessment of Three Posterior Fossa Decompression Techniques and Evaluation of the Evidence Supporting the Efficacy of Syrinx Shunting and Filum Terminale Sectioning in Chiari Malformation Type I. A Systematic Review and Network Meta-Analysis

BACKGROUND

This study aimed to compare the effectiveness of posterior fossa decompression (PFD), posterior fossa decompression with duraplasty (PFDD), and posterior fossa decompression with resection of tonsils (PFDRT) in Chiari malformation type I (CMI). Furthermore, we aimed to evaluate the evidence supporting the efficacy of filum terminale sectioning (FTS), syringosubarachnoid shunting (SSS), and syringoperitoneal shunting (SPS) in CMI.

METHODS

PubMed, Cochrane, and Embase databases were screened for English-language studies published from inception until August 11, 2020. A total of 3593 studies were identified through the searching process. Fifteen cohort studies were included in the systematic review and network meta-analysis.

RESULTS

No studies concerning FTS, SSS, and SPS were found eligible. Therefore, only PFD, PFDD, and PFDRT were compared. PFDD showed significantly higher incidence of complications (relative risk [RR], 3.79; 95% confidence interval [CI], 2.54-5.64) cerebrospinal fluid leak (RR, 9.74; 95% CI, 2.33-40.78) and neurologic deficit (RR, 8.76; 95% CI, 2.08-36.90) than did PFD. Both PFDD and PFDRT achieved higher syringomyelia improvement (RR, 1.23, 95% CI, 1.09-1.39 and RR, 1.32, 95% CI, 1.15-1.51, respectively) and greater clinical improvement (RR, 1.24, 95% CI, 1.10-1.39 and RR, 1.24, 95% CI, 1.08-1.44, respectively) than did PFD. No differences were found between PFDD and PFDRT.

CONCLUSIONS

PFDD and PFDRT are superior to PFD, especially in patients with syringomyelia-Chiari complex, because of greater syringomyelia reduction and better clinical improvement. However, PFDD and PFDRT can be considered equally efficient. There is no evidence pleading in favor of SFT, SSS, and SPS over any PFD technique.