Comparative Analysis of 2D and 3D Metrics for Evaluation of Postoperative Outcomes Following Endoscopic Suturectomy for Sagittal Craniosynostosis

Abstract

To assess whether 3-dimensional (3D) volumetrics can be used to track and evaluate postoperative course of patients treated with endoscopic suturectomy for nonsyndromic sagittal synostosis, we compared changes in 2-dimensional (2D) measurements along with 3D volumetric correlates throughout the period of helmet therapy. Forty-six patients treated at our institution with endoscopic suturectomy for sagittal synostosis were retrospectively reviewed. Head circumference (HC), cephalic index (CI), and total cranial volumes (TCVs) were measured at 3 timepoints following surgery using optical surface scans obtained for helmet orthotics. All measurements showed significant differences between timepoints on the analysis of variance ( P <0.001). There was a significant correlation between CI and TCV (r=0.35, P =0.004) and between HC and TCV (r=0.81, P <0.001). The normalized rate of change over the course of treatment was significantly higher for TCV (36.7%) than for CI (8.8%) and HC (8.4%, P <0.001), with no difference between HC and CI. The authors conclude that 3D metrics were able to reliably follow the course of postoperative 2D metrics. There was a direct and linear correlation between HC and CI with TCV. Total cranial volumes showed the highest rate of sustained change at every timepoint. Although CI and HC plateau after the first measurement, TCV continues to adapt over the course of treatment. These results demonstrate the feasibility and value of volumetrics from 3D imaging to provide a more comprehensive evaluation of postoperative surgical outcomes than traditional 2D metrics without the ionizing radiation traditionally utilized for CT to obtain 3D metrics.