Short-term mortality and its association with independent risk factors in adult spinal deformity surgery

STUDY DESIGN. Retrospective review. OBJECTIVES. To determine postoperative mortality after adult spinal deformity surgery. To determine whether independent risk factors can predict mortality. SUMMARY OF BACKGROUND DATA. Although mortality after adult spinal surgery is reported to range from 0.03% to 3.52%, there is a general paucity of data on mortality and its associated risk factors after adult spinal deformity surgery. METHODS. Three hundred sixty-one adults with spinal deformity underwent 407 corrective procedures. For patients who died within 30 days of the procedure, the following risk factors were examined to determine if each could independently predict mortality: demographic information, American Society of Anesthesiologists' (ASA) classification, operative time, surgical approach, number of fusion levels, primary versus revision surgery, and intraoperative blood loss. RESULTS. Ten of the 407 procedures resulted in death (2.4% mortality): 1 intraoperatively secondary to cardiac ischemia, 3 secondary to sepsis/multiple organ failure, 2 each secondary to pulmonary embolus, uncal herniation/cerebral edema, and shock. The average preoperative ASA levels for patients who died and patients who survived were 3.0 and 2.3, respectively (P < 0.0001). Age, gender, operative time, surgical approach, number of fusion levels, revision status, and estimated blood loss did not have an independently significant correlation to mortality. CONCLUSION. There was a strong association (P < 0.0001) between increasing ASA class and increasing mortality. The other risk factors could not independently predict postoperative mortality within 30 days after adult spinal deformity surgery.