Factors Related to Blood Loss During Fronto-Orbital Advancement

BACKGROUND: Blood loss during fronto-orbital advancement (FOA) remains a significant potential source of morbidity. This study explored variables that might correlate with calculated blood loss (CBL) during this procedure. METHODS: The authors reviewed infants with craniosynostosis who underwent primary FOA (1997-2009). Patient demographics, operative time, and mean arterial pressure (MAP) were recorded. Serial MAPs were averaged for a MAPmean and subtracted from preoperative baseline to calculate MAP%decrease. This provided indicators of both absolute and relative hypotension, respectively. Calculated blood loss was based on preoperative/postoperative hemoglobin values and transfusion volumes and accounted for hemodilutional effects. RESULTS: Ninety infants underwent FOA at an average age of 10.7 ± 12.9 months and mean weight of 9.0 ± 7.0 kg. Average operative time was 4.2 hours, and intraoperative MAP was 56.1 mm Hg, 22.6% lower than baseline. Mean CBL was 259.3 mL, or 39.3% of estimated blood volume, negatively correlating with surgical age (r = -0.033, P < 0.05) and positively trending with operative time (r = 0.55, P < 0.05). Absolute hypotension was associated with greater blood loss, as demonstrated by an inverse relationship between CBL and MAPmean (r = -0.19, P < 0.05). From the perspective of relative hypotension, no association was found between CBL and MAP%decrease. CONCLUSIONS: Greater operative efficiency and deferring operative correction to a later age may diminish blood loss during FOA. The study results also raise serious concerns regarding the hemodynamic benefits of controlled systemic hypotension.