Management of Pre-existing Ventriculoperitoneal Shunt in Posterior Vault Distraction for Lambdoid Craniosynostosis: A Case Report and Technical Note

Abstract

Posterior vault distraction osteogenesis (DO) is an emerging treatment option for craniosynostosis. Operative nuances detailing surgical management are being described with increasing use and experience. In this article, we discuss the surgical management of an 8-month-old male with a ventriculoperitoneal shunt (VPS) diagnosed with bilateral lambdoid craniosynostosis and Chiari I malformation. The patient underwent successful bilateral posterior fossa DO without surgical re-implantation of the shunt. Pre- and post-operative imaging confirmed no migration of the VPS. Intracranial volume increased by 20.1% and posterior fossa volume increased by 39.9%. Our experience illustrates that posterior vault DO can be done safely in the setting of a parieto-occipital VPS, in a single operative setting, without the need of additional procedures.

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

“…Some of the systematically reviewed articles were published before the advent of distraction osteogenesis, but the predominance of cranial vault remodeling in SRC treatment may be partly explained by remarks in some case reports that surgeons would have to contend with potential shunt movement and the complications of installing hardware around the shunt. 20,22 In addition to those present in every systematic review, our study did have several limitations. First, the true incidence of SRC may also be lower than our reported pooled rate as we excluded studies discussing complications of patients shunted for hydrocephalus, but without a single case of SRC.…”

“…In the included studies, the sagittal suture was most involved, cited to be the site of fusion in 88% of single-involvement cases, and was also fused in 98% of cases when more than one suture was involved. Other reports of SRC in the literature share this prevalence of sagittal closure and it is also known to be characteristic of all-cause craniosynostosis 1,18,20,23–25 . Whether this is related to the site of shunt placement was addressed by Golinko et al, 1 who found that there is no relationship between the location of shunt placement and involved sutures.…”

“…There is also debate regarding whether craniosynostosis diagnosed <1 year after shunt placement could be due to a hereditary course versus causal shunt disruption. 1,[19][20][21][22] In addition, diagnosis relative to the timing of shunt placement may be complicated as even if suture closure is not fully visualized on a CT scan, it may be visibly open but functionally fused due to the pathological interplay between the dura and cranial bone. 1 In the included studies, the sagittal suture was most involved, cited to be the site of fusion in 88% of single-involvement cases, and was also fused in 98% of cases when more than one suture was involved.…”

“…Other reports of SRC in the literature share this prevalence of sagittal closure and it is also known to be characteristic of all-cause craniosynostosis. 1,18,20,[23][24][25] Whether this is related to the site of shunt placement was addressed by Golinko et al, 1 who found that there is no relationship between the location of shunt placement and involved sutures. While overall shunt revisions in the entire cohort were comparable to those that developed SRC in our included studies, a multivariate logistic regression conducted by Bryant et al 18 found that having 2 or more shunt revisions was an independent predictor of SRC.…”

“…The range in average time between initial shunt placement and SRC suggests that development can take place in months to years after shunting. There is also debate regarding whether craniosynostosis diagnosed <1 year after shunt placement could be due to a hereditary course versus causal shunt disruption 1,19–22 . In addition, diagnosis relative to the timing of shunt placement may be complicated as even if suture closure is not fully visualized on a CT scan, it may be visibly open but functionally fused due to the pathological interplay between the dura and cranial bone 1 …”