Predicting Surgical Outcomes in Type 1 Chiari Malformation: The Role of Preoperative Radiographic Indicators

Saturday, May 4, 2024

4:46 PM – 4:48 PM CT

Location: S405b

Presenting Author(s)

Jonathan Tangsrivimol, MD (he/him/his)

Medical Doctor
Department of Neurosurgery, Chulabhorn Hospital, Chulabhorn Royal Academy
Bangkok, Thailand

Co-Author(s)

Daniel M. Prevedello, MD (he/him/his)

Professor of Neurological Surgery
The Ohio State Wexner Medical Center Department of Neurological Surgery
Columbus, Ohio, United States

Co-Author(s)

MA

Mohammad Bilal Alsavaf, n/a

Medical Doctor
Department of Otolarygology Head and Neck Surgery, United States
GF

Guilherme Finger, MD

Neurosurgical Oncology Fellow
The Ohio State Wexner Medical Center Department of Neurological Surgery, United States
Kyle C. Wu, MD

Assistant Professor of Neurological Surgery
The Ohio State Wexner Medical Center Department of Neurological Surgery
Columbus, OH, US

Disclosure(s):

Daniel M. Prevedello, MD: ACE Medical: Royalty Recipient (Ongoing); BK Medical: Consultant (Ongoing); Integra: Consultant (Ongoing); KLS Martin: Royalty Recipient (Ongoing); Mizuho America: Royalty Recipient (Ongoing); Stryker: Consultant (Ongoing)

Jonathan Alan Tangsrivimol, MD: No financial relationships to disclose

Kyle C. Wu, MD: No financial relationships to disclose

Introduction: Type 1 Chiari Malformation (CMI) patients most commonly present with suboccipital headache thought to be caused by obstructed cerebrospinal fluid flow at the foramen magnum. A characteristic finding among these patients is cough-induced headaches, which may be a positive predictor of a favorable surgical outcome. suggesting that posterior cerebral fossa area measurements could aid in surgical decision-making. The authors aimed to identify preoperative radiographic indicators that could predict surgical outcome after posterior fossa decompression in CMI.

Methods: Following approval from the Institutional Review Board, the authors performed a retrospective chart review including symptomatic patients diagnosed with CMI that were surgically treated at a single institution from July 2010 to Dec 2022. The data collected include demographic variables, clinical presentation, imaging parameters, and treatment outcomes. Imaging parameters were obtained based on a preoperative magnetic resoinance imaging (MRI) and the same measurements were performed postoperatively.

Results: A total of 95 patients were included in the analysis. Correlative analyses indicated significant improvements in multiple symptoms following surgery, primarily headache. Significant differences were observed in the width of the 4th ventricle, cerebellar-to-pons width, and height of the cerebellum (P value = 0.007, 0.002, and < 0.001 retrospectively). Changes in measurements were not significantly associated with changes in pain score, except for 4th ventricle width, which negatively correlated with postoperative pain score (r= -0.25 ; P value = 0.014). Comparing preoperative values with the normal population, the cerebellar width, 4th ventricle width, tentorial angle, and McRae line exhibited significant differences.

Conclusion : Surgical decision making for patients with CM1 can be challenging with a dearth of objective data to inform prognosis after surgery. Here, we demonstrate that the degree of radiologic abnormality found in posterior fossa structures may be a useful indicator to help select which patients with CM1 may benefit from surgery