27. Parietal Bone Thickness Predicts Intraoperative Blood Loss and Transfusion in Patients Undergoing Spring Mediated Cranioplasty for Non-syndromic Sagittal Craniosynostosis

Abstract

Purpose: Variables that can predict outcomes in patients with craniosynostosis, including bone thickness, are important for surgical decision making but incompletely understood. Recent studies have demonstrated relative risks and benefits of surgical techniques for correcting head shape in patients with non-syndromic sagittal craniosynostosis. The purpose of this study was to characterize relationships between parietal bone thickness and perioperative outcomes in patients undergoing spring mediated cranioplasty (SMC) for non-syndromic sagittal craniosynostosis. Methods: Patients undergoing craniectomy and SMC for non-syndromic sagittal craniosynostosis at a quaternary pediatric hospital between 2014 and 2021 were included. Parietal bone thickness was determined from patient preoperative CTs at 27 suture-related points on parietal bones: at the suture line and at 0.5 cm, 1.0 cm, 1.5 cm, and 2.0 cm from the suture anteriorly, medially, and posteriorly. Preoperative skull thickness was correlated to intraoperative blood loss, need for intraoperative transfusion, and duration of hospital stay. Results: During the study interval, 124 patients with mean surgery age of 3.59 ± 0.87 months and average parietal bone thickness 1.83 ± 0.38 mm were included in this study. Estimated blood loss (EBL) and EBL/kg were associated with parietal bone thickness 0.5 cm (ρ = 0.376, p < 0.001; ρ = 0.331, p = 0.004, respectively) and 1.0 cm (ρ = 0.324, p = 0.007; ρ = 0.245, p = 0.033, respectively) from the suture line. Patients with thicker parietal bone 0.5 cm (OR: 18.08, p = 0.007), 1.0 cm (OR = 7.16, p = 0.031), and 1.5 cm (OR: 7.24, p = 0.046) from suture line were significantly more likely to have undergone transfusion when controlling for age, sex, and race. Parietal bone thickness was associated with length of hospital admission (β = 0.575, p = 0.019) when controlling for age, sex, and race. Age at time of surgery was not independently associated with these perioperative outcomes. Conclusion: Parietal bone thickness, but not age at surgery, may predict perioperative outcomes including transfusion, EBL, and length of hospital admission. Need for intraoperative transfusion and EBL were most significant for parietal bone thickness 0.5 - 1.5 cm from the suture line, within the anticipated area of suturectomy. Parietal bone thickness may have important implications for patients undergoing craniofacial surgery to anticipate transfusion and length of hospital admission.