Increased risk of postoperative wound complications among obesity classes II & III after ALIF in 10-year ACS-NSQIP analysis of 10,934 cases

BACKGROUND CONTEXT Anterior lumbar interbody fusion (ALIF) procedures for lumbar spine disease have been increasing amid a growing obese patient population with limited studies available focusing exclusively on risk-factors for post-operative ALIF complications. PURPOSE The objective of this study was to compare 30-day post-operative complications among different obesity World Health Organization (WHO) classes according to body mass index (BMI) in comparison to non-obese patients who underwent an ALIF procedure. STUDY DESIGN/SETTING Retrospective cohort study of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) from 2009 to 2019. PATIENT SAMPLE A total of 10,934 patients undergoing an ALIF. OUTCOME MEASURES Primary outcome measures include 30-day cardiac, pulmonary, urinary, infectious, and wound complications. Secondary outcomes included rates of blood transfusion, reintubation, deep vein thrombosis, pulmonary embolism, 30-day return to the operating room (OR), and 30-day mortality. METHODS Patients were identified by use of the current procedural terminology codes 22558 & 22585 from 2009 to 2019. Patients were divided into the following groups: non-obese (BMI 18.5–29.9 kg/m2), Obese I (BMI 30–34.9 kg/m2), Obese II (BMI 35–39.9 kg/m2), and Obese III (BMI ≥40 kg/m2). Age, gender, race, American Society of Anesthesiologists (ASA) status, smoking status, hypertension requiring medication, steroid used, chronic obstructive pulmonary disease (COPD), history of a bleeding disorder, & diabetes were identified as risk factors after a univariate analysis conducted for demographic variables and pre-operative comorbidities. A multivariate logistic regression analysis was then performed to adjust for these preoperative risk factors and compare obesity classes I-III to non-obese patients. RESULTS Obesity classes II and III had a significant odds ratio (OR) for superficial infection (OR:2.7, 95%CI(1.7-4.5); OR:2.8, 95%CI(1.5-5.2) respectively), organ space infection (OR:3.8, 95%CI(1.6-7.4); OR:3.2, 95%CI(1.1-9.9) respectively), wound disruption (OR:2.8, 95%CI(1..1-7.4); OR:4.6, 95%CI(1.6-13.6) respectively), and total wound complication (OR:2.6, 95%CI(1.8-3.9); OR:3.4, 95%CI(2.2-5.4) respectively) following a multivariate logistic regression analysis. CONCLUSIONS Risk for post-operative wound complications following an ALIF were found to be significantly higher for obesity classes II-III in comparison to non-obese patients. These findings can further support the use of additional wound care in the perioperative setting for certain levels of obesity.