Craniosynostosis is a rare disorder characterized by a premature fusion of one or more sutures of the skull. Craniosynostosis is usually diagnosed in the first years of life. Several complications may be identified if untreated, notably, developmental delay, and vision problems.

In some patients with craniosynostosis a decrease in cerebral blood perfusion can be identified. It might be related to the constriction of the brain caused by premature sutural fusion or the localized constriction of venous sinuses.

In this study the investigator use the NIRS which is defined as a non-invasive technique to monitor hemodynamic parameters and hemoglobin oxygen saturation of the brain during the surgical correction of the craniosynostosis. By applying this method the investigator will be able to analyse the changes in cerebral hemoglobin oxygen saturation related to the modification of the skull.

Determining changes in brain oxygen saturation by using NIRS before, during and after surgery will help both to better understanding the impact of surgical decompression on improving cerebral oxygenation and to better adapt anaesthesia strategies during surgery.

Inclusion Criteria:

• Boys and girls.
• Aged 3 to 18 months old.
• Subjects with a craniosynostosis diagnosis confirmed by imaging.
• Craniosynostosis requiring a corrective surgery in ventral position.
• Parents/ legal guardian must provide non opposition prior to participation in the study.

Exclusion Criteria:

- Craniosynostosis planned to be corrected by an endoscopic craniectomy or in dorsal position.

Children with craniosynostosis.