Medical Complications After Adult Spinal Deformity Surgery: Incidence, Risk Factors, and Clinical Impact.

Study Design: Retrospective review of a prospective multicenter database evaluating surgical adult spinal deformity (ASD) patients.
Objective: This study aims to identify risk factors for medical complications in ASD patients undergoing surgery.
Summary of Background Data: ASD surgery is known for its high complication rate. This study examines baseline patient characteristics for predictors of medical complications in surgical ASD patients.
Methods: Intra and perioperative medical complications were included. Medical complications were: infection, pneumonia, urinary tract infection, c-difficile, sepsis, stroke, delirium, deep venous thrombosis, pulmonary embolism, myocardial infarction, arrhythmia, congestive heart failure, pneumothorax, atelectasis, adult respiratory distress syndrome, bowel obstruction, ileus, and renal failure. Potential predictors were identified using univariate testing. Multivariate Poisson regression was used to determine independent predictors of medical complications. Health-related quality of life (HRQL) was measured using the Oswestry Disability Index and SF-36. Multivariate repeated measures mixed models were used to examine HRQL.
Results: Four hundred forty-eight patients were included. The incidence of patients with at least one medical complication was 26.8%. Potential predictors included: age, BMI, anemia, arthritis, depression, cardiac history, hypertension, lung disease, history of PVD, Charlson Comorbidity Index, ASA, smoking, sex, and the number of years with spine problems. Independent predictors identified on multivariate logistic regression modeling included hypertension (IRR 2.43 P = 0.0001), smoking (IRR 2.49 P = 0.0001), and number of years with spine problems (IRR 1.23 P = 0.03). Despite medical complications, patients experienced significant improvements in HRQL, as measured by the SF-36 (P = 0.0001) and oswestry disability index (P = 0.0001). The rate of improvement and overall improvement compared with baseline were not statistically different than that of patients who did not experience medical complications.
Conclusion: Risk factors for the development of postoperative medical complications after correction of ASD include smoking, hypertension, and duration of symptoms. Patients who have one or more of these risk factors should be identified and informed during informed consent of their increased risks. They should be optimized preoperatively, and followed closely during the postoperative period.
Level of Evidence: 3.