Comparison of surgical invasiveness and morbidity of adult spinal deformity surgery to other major operations

Background Context: Adult spinal deformity (ASD) surgeries are complex, involving long operative times and surgical morbidity. It is currently unclear how the invasiveness of ASD surgery compares to other major operations. Purpose: To: (1) develop a quantitative score of surgical morbidity and invasiveness, and (2) compare this score between ASD surgery and other major operations. Study Design: Retrospective review of prospectively collected data. Patient Sample: A prospective surgical registry was used to identify all patients undergoing ASD surgery involving ≥ 7 segments. Seventeen additional procedures were included: coronary artery bypass grafting (CABG), pancreatectomy, and esophagectomy, among others. Outcome Measures: Perioperative factors (operative time, transfusions, ventilation) and complications were collected and combined with a previously validated Postoperative Morbidity Survey to create a Surgical Invasiveness and Morbidity Score (SIMS). Methods: Computed scores were compared across surgeries using Welch's t-test. Multiple linear regression modeling was used to compare the SIMS of major surgeries relative to ASD while controlling for patient demographics and comorbidities. Results: A total of 1,245,282 surgical patients were included, 4,656 of which underwent ASD surgery. After multiple regression modeling controlling for patient demographics and comorbidities, ASD surgery ranked fourth in SIMS. ASD surgery had a significantly greater SIMS than 13 other major procedures including 6th esophagectomy (adjusted mean difference=-0.05, 95%CI -0.01-0.09, p<.001), 8th pancreatectomy (-0.40, 0.37-0.44, p<.001), 11th craniotomy for tumor (-1.01, 0.98-1.04, p<.001), and 12th sacral chordoma resection (-1.31, 1.26-1.37, p<.001). Conclusions: ASD surgery was associated with significantly greater SIMS than many other major operations, even when controlling for important perioperative factors. These data have implications for patient counseling, resource allocation, and informed consent.