# Concurrent posterior vault expansion and extradural Chiari decompression in syndromic and non-syndromic craniosynostosis: a case series

## TL;DR

This case series examines a combined surgical approach for treating craniosynostosis and Chiari malformation, showing symptom improvement in most patients.

## Contribution

The study introduces a concurrent surgical technique for managing Chiari malformation and craniosynostosis with posterior vault expansion.

## Key findings

- All patients reported symptom resolution at first follow-up, with 85.7% at last follow-up.
- Half of the patients showed improvement or stable presentation of Chiari malformation on post-operative imaging.
- One patient experienced a post-operative complication (distractor infection) without long-term effects.

## Abstract

Chiari malformation (CM) may occur in patients with craniosynostosis, and the presence of both in anatomically similar locations allows for simultaneous treatment. In this study, we analyze concurrent posterior vault distraction osteogenesis (PVDO) or posterior vault reconstruction (PVR) with extradural Chiari decompression for the management of suspected increased intracranial pressure (ICP) in patients with syndromic and atypical non-syndromic craniosynostosis.

Patients who underwent concurrent PVDO/PVR and extradural Chiari decompression at a single institution from 2008 to 2024 were included. Of interest were patient/caregiver-reported symptomatology and radiographic findings related to CM reported by a board-certified neuroradiologist. Descriptive, Chi-square, and Fisher’s exact tests were utilized for analysis.

Eight patients met the inclusion criteria. Fifty percent (n = 4) had syndromic craniosynostosis and 50% (n = 4) had non-syndromic craniosynostosis; half (n = 4) underwent PVDO, and half (n = 4) underwent PVR. One patient (12.5%) had a post-operative complication (distractor infection), with no long-term sequelae. One hundred percent (n = 8) had resolution of clinical symptoms at the first follow-up, and 85.7% (n = 6/7) at the last follow-up; 50.0% (n = 4) of patients had improvement, and 50.0% (n = 4) had a stable presentation of CM on post-operative imaging. While most patients with radiologic improvement in CM were in the PVDO group compared to PVR (75% (n = 3/4) vs. 25% (n = 1/4), p = 0.5), this study was underpowered to detect a significant difference between techniques.

Posterior vault expansion with extradural Chiari decompression in patients with concomitant suspected increased ICP and craniosynostosis appears safe and relatively effective at extended follow-up. Additional study of its long-term effects, patient selection, and comparison of PVDO vs PVR is warranted.