J Neurol Surg B 2020; 81(01): 068-074
DOI: 10.1055/s-0039-1681040
Original Article
Georg Thieme Verlag KG Stuttgart · New York

Analysis of Clinical and Radiographic Outcomes of the Angle between Clivus and Supraocciput in Patients with Chiari's Malformation Type I Following Surgical Decompression

Xin Wang
1  Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
,
Jun Gao
1  Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
,
Shiyuan Han
1  Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
,
Zhimin Li
1  Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
,
Yongning Li
1  Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
› Author Affiliations
Funding None.
Further Information

Publication History

04 November 2018

26 January 2019

Publication Date:
21 February 2019 (online)

Abstract

Background The objective of this study was to investigate whether different angles between the clivus and supraocciput (C–SO angle) in patients with Chiari's malformation type I (CMI) after posterior fossa decompression lead to different clinical and radiographic outcomes.

Methods A total of 73 patients who underwent surgical decompression at our institution between 2010 and 2016 were retrospectively divided into two groups: group A, with an angle less than 96 degrees, and group B, with an angle ≥ 96 degrees. Patient clinical outcomes were determined using the Chicago Chiari Outcome Scale (CCOS), and radiographic outcomes were determined by changes in the syrinx size before and after surgery. Direct comparisons were made between the two groups.

Results There were no statistically significant differences between the two groups regarding demographics, preoperative symptoms or radiographic characteristics (p > 0.05), except for the cerebellar tonsillar descent (p ≤ 0.001). The mean overall CCOS score was 13.11 ± 1.99. The total CCOS score was significantly different between the two patient groups (p < 0.05). Moreover, group A demonstrated significantly better postoperative improvements than group B in clinical outcome measures based on the CCOS system (p = 0.035). For radiographic outcomes, the change in the syrinx between the two groups was also significantly different, with a value p = 0.024.

Conclusions A direct comparison between the two groups revealed that a smaller C–OS angle (< 96 degrees) was related to unsatisfactory clinical and radiographic outcomes. Thus, the C–OS angle may emerge as a predictor of clinical or radiographic outcomes following surgical decompression in patients with CMI.

Author Contributions

Authors Y.L. and X.W. designed the research; authors X.W., J.G., S.H., and Z.L. performed the research; authors Y.L. and J.G. collected the data; X.W. analyzed and prepared the manuscript; besides, all authors reviewed and commented on the manuscript.


Ethics Approval and Consent to Participate

Not applicable.


Consent for Publication

The manuscript has not been published previously, in any language, in whole or in part, and is not currently under consideration elsewhere.


Competing Interests

The authors declare that they have no competing interests.