Evaluation of surgical outcomes in craniosynostosis

Abstract

Background: A continuous and objective evaluation of surgical outcomes must be an integrated part of the technical development. The present thesis has the ambition to innovate the evaluation of surgical results allowing systematic and objective assessment of the surgical procedures used for metopic and unicoronal craniosynostosis (UCS). Material & methods: The effect of springs on hypotelorism was studied by measuring the bony interorbital distance (BIOD) and the axes of the orbits on cephalograms. Thereafter, the pre- and post-operative BIOD in patients operated with spring-assisted surgery (SAS) was compared to that of patients operated using the traditional cranioplasty and to a control group. The effect on forehead symmetry of a fronto-orbital advancement (FOA) and of a more radical forehead substitution with a calvarial bone graft in UCS was measured. To be able to evaluate our results, a computer tool that measured frontal symmetry was developed. Intracranial volume in metopic synostosis, before and after surgery was measured by using a newly developed computer tool that measured volume in CT scans. Results: 1. Springs had effect on hypotelorism and orbital shape. 2. SAS before 6 months of age normalized BIOD, a result previously not achieved. 3. The computer was simple to use and gave a precise assessment of forehead symmetry. 4. Forehead reconstruction with a calvarial bone graft gives better forehead symmetry than FOA in UCS. 5. Total intracranial volume in metopic synostosis was normal before surgery but significantly lower than in controls at 3 years of age. The ratio frontal-to-total volume before surgery was low in patients with metopic synostosis. The ratio was improved, but not normalized, by surgery. Conclusion: Systematic evaluation with quantitative measurements of surgical results is important to be able to objectively assess outcomes and to develop and compare surgical techniques.