The Lost and Variable Cause: A Systematic Review of Shunt-Related Craniosynostosis Occurrence

Shunt-related craniosynostosis (SRC) is the premature fusion of cranial sutures possibly due to a loss of tension across dura and suture lines after placement of a shunt for hydrocephalus. As modifications in approaches toward shunting represent a modifiable risk factor, prior literature has investigated the determinants and outcomes. However, the data remain highly variable and are limited by single-institution studies.

A systematic search of PubMed, Embase, and Web of Science from inception to February 2022 was conducted. Studies were screened by 2 reviewers for eligibility based on predefined inclusion/exclusion criteria.

In the 9 included articles, the average follow-up time for the entire cohort ranged from 1.5 to 4.2 years. The pooled incidence of SRC across all 9 studies was 6.5% (140/2142), with an individual range of 0.53% (1/188) to 48.8% (61/125). The average time from shunt placement to SRC diagnosis ranged from 0.25 years to 4.6 years. 61% (65/110) of cases included only one suture, 88% (25/28) of these involved the sagittal suture, and those cases with multiple fusions also had 98% involvement of the sagittal suture (45/46). Overall, 94% (1783/1888) of patients had a fixed shunt placed.

Shunt-related craniosynostosis is likely an underreported complication in the treatment of hydrocephalus. Older age at shunt placement, increased number of shunt revision procedures, and lower valve pressure settings may be risk factors for SRC development. Results also indicate that craniosynostosis can develop months to years after shunting. Future quality studies with standardization of data reporting processes are warranted to investigate this clinical problem.