Predictive factors for intraoperative blood loss in surgery for adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity. Posterior spinal fusion remains an important surgical treatment for AIS. This study aims to determine the predictive factors for intraoperative blood loss in AIS surgery.

Patients who had undergone posterior spinal fusion for adolescent idiopathic scoliosis in a single university hospital were reviewed over a 7-year period. Predictive factors for intra-operative blood loss were studied by multivariate analysis to derive a regression model. Receiver operating characteristic analysis was performed to determine the cut-off values of factors contributing to significant intraoperative blood loss (≥500 ml).

Two hundred and twelve patients were included. Intraoperative blood loss was found to be correlated with gender (r_s = 0.30 (0.17-0.43)), preoperative hemoglobin level (r_s = 0.20 (0.04-0.31)), preoperative Cobb angle (r_s = 0.20 (0.02-0.29)), number of fused levels (r_s = 0.46 (0.34-0.58)), operation duration (r_s = 0.65 (0.54-0.75)), number of anchors (r_s = 0.47 (0.35-0.59)), and p-value ranged from < 0.001 to < 0.05. Significant intraoperative blood loss was influenced by the male gender, operation duration greater than 257.5 min and more than 10 anchors used.

Male gender, increased operation duration and higher number of anchors predicted higher intra-operative blood loss.