125. Impact of preoperative bariatric surgery on elective spine fusion and decompression: a systematic review and meta-analysis

Abstract

<h3>BACKGROUND CONTEXT</h3> For decades, the obesity rate in the United States has been climbing. Concurrently, the number of bariatric surgeries has also been steadily increasing. Therefore, the incidence of patients undergoing elective spine surgery who have had bariatric surgery in the past is also rising. Studies have investigated outcomes of other orthopedic procedures, such as arthroplasty, in patients who have had bariatric surgery previously. However, the effects of bariatric surgery on the outcomes of spine surgery have only been explored in studies with notable limitations. This network meta-analysis (NMA) of more than 330,000 patients across four retrospective cohort studies compares the outcomes of patients receiving spine surgery after bariatric surgery to two control sets of patients also reciving spine surgery who are either obese or nonobese. <h3>PURPOSE</h3> In this study, we present a comprehensive network meta-analysis of 330,226 patients across four retrospective cohort studies who received spine surgery. Of these patients, 34,962 underwent bariatric surgery prior to their spinal operation. Our goal is to understand how outcomes of spine surgery compare amongst those who have undergone bariatric surgery prior to spine surgery compared to obese patients receiving spine surgery and nonobese patients receiving spine surgery. <h3>METHODS</h3> A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Guidelines was performed on peer-reviewed articles from PUBMED, Medline, Web of Knowledge and Google Scholar. Studies evaluating outcomes of patients receiving bariatric surgery prior to elective spine surgery were compared to obese and nonobese controls. Four comparative retrospective or prospective cohort studies (2018-2021) were identified that met inclusion criteria. A network meta-analysis was performed to assess outcomes of bariatric patients receiving elective spine surgery compared to obese and non-obese control groups. <h3>RESULTS</h3> Four studies consisting of 330,226 total patients were included. Of these patients, 34,962 were bariatric patients, 145,069 were obese control patients, and 150,195 were nonobese control patients who underwent spine surgery. NMA found that postsurgical complications including the following categories DVT/PE, renal, cardiac and total wound were more likely to occur in obese patients than in bariatric patients (odds ratios (OR) of 0.31, 0.27, 0.44, 0.62 respectively; p <0.05 for all categories). Additionally, 90-day readmission for bariatric patients was less likely than obese patients (OR=0.47, p <0.05). Mortality was found to be lower amongst bariatric patients receiving spine surgery compared to obese control patients (OR=0.14, p <0.05). One continuous outcome measured was hospitalization length, which was found to be less in bariatric patients compared to obese control patients (OR=0.18, p <0.05). NMA found a significant difference between bariatric patients and nonobese control patients in total wound complications and 90-day readmission. Bariatric patients were found to be more likely to experience wound complications and be readmitted within 90 days of operation compared to nonobese patients (OR=4.18, p 0.05 wound; OR=5.08, p < 0.05 readmission). Other outcomes comparing bariatric patients to nonobese patients showed no significant difference. <h3>CONCLUSIONS</h3> Our NMA suggests that bariatric patients undergoing elective spine surgery have generally better postsurgical outcomes than obese patients undergoing spine surgery. However, bariatric patients compared to nonobese patients have a higher likelihood of readmission in 90 days and a higher wound complication likelihood. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.