Risk factors of massive blood loss during posterior long-level instrumentation surgery in degenerative lumbar scoliosis

English Keywords:Degenerative lumbar scoliosis  Long levels fusion  Massive blood loss  Risk factors

English Abstract:

  【Abstract】 Objectives: To investigate the risk factors of massive blood loss during posterior long-level instrumentation in degenerative lumbar scoliosis(DLS). Methods: The study retrospectively included 173 patients with DLS who underwent long-segmental segmentation(≥4 levels). They were divided into two groups according to the intraoperative blood loss, massive blood loss group (proportion of blood loss ≥30%) and non-large blood loss group(proportion of blood loss <30%). The data of the two groups before, during and after operation were compared, including gender, age, body mass index(BMI), smoking, drinking status, preoperative bone quality, preoperative American Society of Anesthesiologists(ASA), preoperative Cobb angle, coronal vertical axis(CVA) and sagittal vertical axis(SVA) imbalance, apical vertebral translation(AVT), lumbar lordosis(LL), Cobb and LL change, operation time, fusion levels, decompression levels, intervertebral fusion segments, intraoperative osteotomy and osteotomy level, sacrum fixation, tranexamic acid(TXA) usage, intraoperative blood loss, intraoperative and postoperative blood transfusion, medical expenses. Outcome parameters included proportion of blood loss, perioperative blood transfusion and blood transfusion rate. Univariate analysis and multiple regression analysis were used to explore the risk factors that led to massive blood loss during surgery. Results: There were 66 patients enrolled in the massive blood loss group, and 106 patients in the control group. When compared to data in the non-large blood loss group by using Univariate analysis, in the massive blood loss group the BMI was significantly lower(P=0.046), the preoperative Cobb angle was larger(P<0.001), the preoperative vertebral offset distance was larger(P=0.002), the fusion levels were more(P<0.001), and the intervertebral fusion segment was more(P=0.043), the osteotomy level was higher(P<0.001), the proportion of intraoperative TXA usage was smaller(P=0.046), and perioperative blood transfusion(P=0.015), blood transfusion rate(P=0.035), postoperative hospital time(P=0.035), hospitalization cost(P=0.023) were higher. Multivariate logistics binary regression analysis showed that when BMI increased 1kg/m2, the risk of massive blood loss during surgery decreased by 9.3%. When the value of Cobb angle correction increased by 1° or the fusion levels increased by 1 segment, the risk of massive blood loss increased by 5.9% and 58.9%, respectively. For each additional unit of intervertebral fusion segment, the risk of massive blood loss increased by 1.174 times. Intraoperative third or higher level osteotomy increased the risk of massive blood loss during surgery by 9.262 times. The usage of TXA during surgery reduced the risk of massive blood loss during surgery by 71.2%. Conclusions: Smaller BMI, larger preoperative Cobb angle, larger preoperative AVT, increased Cobb angle correction, increased fusion level, increased intervertebral fusion level and intraoperative osteotomy, higher osteotomy grade and no use of TXA are potential risk factors of massive blood loss in long-level fusion surgery in patients with DLS. Among them, smaller BMI, increased Cobb angle correction, increased fusion levels, increased intervertebral fusion levels, third or higher level osteotomy and no use of TXA during surgery are independent risk factors for massive blood loss during surgery.