Risk factors analysis of early complications in posterior long-level fusion and fixation for adult degenerative scoliosis

English Keywords:Adult degenerative scoliosis  Long levels fusion  Early complications  Risk factors

English Abstract:

  【Abstract】 Objectives: To investigate the risk factors of early complications during posterior long-level instrumentation in the treatment of adult degenerative scoliosis(ADS). Methods: The data of 216 patients with ADS who underwent posterior long-segmental instrumentation(≥4 levels) were reviewed retrospectively. According to whether complications occurred within 6 weeks or not after operation, the patients were divided into the early complications group and non-early complications group. The perioperative data of the two groups were compared. General data included gender, age, duration of lumbar and leg symptoms, past medical history, smoking history, T-value of osteoporosis, and preoperative classification by American Society of Anesthesiologists(ASA). The operative data included operation time, number of fixation and fused levels, osteotomy grade, and intraoperative blood loss. Postoperative data included whether there were postoperative complications, the situation of complications, volume of drainage, postoperative red blood cell count, and hemoglobin level. Potential risk factors were identified by univariate logistic regression analysis after comparing the difference of clinical data in the two groups. Multivariate logistic regression analysis was performed to verify the independent risk factors of early complications. Results: There were 89(41.2%) patients enrolled in the early complications group, and 127(58.8%) in the control group. There were statistically significant differences between the two groups(P<0.05) in terms of the duration of low back pain(P=0.034), count of red blood cell on the first day after surgery(P=0.017), anesthesia time(P<0.001), operation time(P<0.001), fixation and fusion levels(P<0.001), intraoperative osteotomy(P=0.027), the osteotomy grade(P=0.002) and level(P=0.049), intraoperative blood loss(P=0.048), intraoperative urinary volume(P=0.022), total intraoperative input liquid(P=0.005), volume of autologous blood transfusion(P=0.022), postoperative drainage volume(P=0.002), and hospital stay(P<0.001). These parameters were analyzed by univariate logistic regression, which showed that the increase of fixation and fusion levels, longer duration of surgery, more intraoperative blood loss, more total intraoperative liquid input, grade 3 and above Osteotomy, more volume of autologous blood transfusion, more postoperative drainage volume, and fewer count of red blood cell on the first day after surgery were the potential risk factors of early complications. Analysis of the multivariate logistic regression showed that more total postoperative drainage volume and grade 3 or above osteotomy were independent risk factors for early postoperative complications. When patients underwent grade 3 or above osteotomy, the risk of early complications was 4.577 times that of those who underwent grade 2 or below or even no osteotomy(P=0.041). The risk of early complications increased 12.7% with every 100ml increase of postoperative drainage volume (P<0.001). The predictive accuracy of the potential risk factors was analyzed using the area under the receiver operating characteristic(ROC) curve(AUC). The result was that the duration of surgery ≥244 minutes, the fixation and fusion levels ≥6 levels, and the total postoperative drainage volume ≥1745ml had certain accuracy in predicting the occurrence of early postoperative complications. Conclusions: High drainage volume and grade 3 or above osteotomy are closely related to early postoperative complications, it is beneficial to reduce the early postoperative complications by reducing the operative time and choosing the appropriate fixation and fusion level.