Retrospective Investigation of Cranial Volume and Cephalic Index in Patients with Nonsyndromic Sagittal Synostosis Operated by Total Vault Remodeling

Background: Premature fusion of cranial sutures affects skull development and leads to head deformity. Intracranial pressure increase and brain growth restriction can occur in untreated craniosynostosis. Operative treatment aims to achieve an immediate and long-lasting correction of skull shape that is close to the average and to prevent or release possible increased intracranial pressure by increasing the intracranial volume (ICV) or normalizing the ICV if it is already below the standards. This study was designed to evaluate the effect of a total calvarial reconstruction on skull development in patients with nonsyndromic sagittal synostosis. Material and Methods: The study population included 19 male and 5 female patients with isolated nonsyndromic sagittal suture synostosis. During the operation, temporarily fixed prebent metal plates provided an intraoperative reference for the desired cranial expansion gain of height and shortening. Preoperative and postoperative ICVs and cephalic indices were measured on computed tomography datasets using the software program ImageJ and were compared with one another and with normative data. Results: The male population presented with a preoperative mean ICV of 863.3 cm³. A postoperative mean ICV increase of 243.5 cm³ (p < 0.001) and a further ICV enlargement (p < 0.001) was measured. The mean CI changed from 71.0% preoperatively to 75.4% postoperatively (p = 0.002) and decreased insignificantly in the follow-up (p = 0.546). The female population had a preoperative mean ICV of 804.9 cm³. Postoperatively, the mean ICV increased by 211.1 cm³ (p = 0.043) and also increased in the follow-up (p = 0.043). Their mean CI values increased from 66.5% preoperatively to 72.8% (p = 0.043) postoperatively and decreased insignificantly in the follow-up (p = 0.345). Conclusion: This method of total vault remodeling provides reliable ICV increase and improvement in length and width of skull proportions beyond the immediate postoperative period together with an ICV increase.