P85. Delayed staging during same hospitalization increases complication risk following adult spinal deformity surgery

Abstract

<h3>BACKGROUND CONTEXT</h3> Since circumferential adult spinal deformity (ASD) surgery can lead to high surgical burden for the patient, surgeons may elect to stage these procedures during the same hospitalization. As a result, there is a trend toward planning same-hospitalization staged ASD surgeries by performing an anterior lumbar interbody fusion (ALIF) prior to a subsequent staged posterior fusion. <h3>PURPOSE</h3> The aim of this study was to determine optimal timing for staging (early vs delayed) thoracolumbar ASD surgery within the same hospitalization. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of a multicenter database. <h3>PATIENT SAMPLE</h3> A total of 158 surgical ASD patients undergoing anterior and staged posterior spinal fusion ≥5 levels. <h3>OUTCOME MEASURES</h3> Our outcome measures were 90-day complication rates, postoperative alignment, and 2-year ODI. <h3>METHODS</h3> Using a prospective, multicenter database, we identified 158 surgical ASD patients undergoing first an anterior surgery followed by a staged posterior spinal fusion ≥5 levels during the same hospitalization. Stratum-specific likelihood ratio (SSLR) analysis was performed to calculate a cutoff point beyond which 90-day complications were increased. The cutoff generated through SSLR were confirmed with multivariable logistic regression analysis controlling for age, gender, levels fused for each stage, preoperative alignment, three-column osteotomy, and Charlson Comorbidity Index. The outcome measures were 90-day complication rates, postoperative alignment, and 2-year ODI. Multivariable analyses were performed with logistic, Poisson and linear regressions where appropriate. <h3>RESULTS</h3> Utilization of staged procedures increased 4x from 2008-2019, and the mean staging interval was 3 days (range 1-8). On SSLR analysis, patients were divided into two staging categories based on complication risk: early (<6 days, range 1-5, N=139) versus delayed (≥ 6 day, range 6-8, N=19). On bivariate analysis, the delayed group had higher 90-day complication rates (68.4% vs 32.4%, p=0.002) and longer operative times (638 min vs 739 min, p=0.020) relative to the early group. Adjusting for covariates on multivariable analysis, patients with delayed staging had significantly greater odds of 90-day complications (OR=7.57, p=0.006), and longer total operative time (beta=119, p=0.035). With respect to specific complications, delayed staging carries increased odds of infection compared to early staging (OR=11.8 p=0.031). There were no significant differences in postoperative alignment or 2-year ODI between the groups (p>0.05 for all). <h3>CONCLUSIONS</h3> Compared to early staging (< 6 days) of ALIF and subsequent staged posterior fusion, delayed staging (≥ 6 days) is associated with greater odds of 90-day complications, particularly infection. With the growing trend toward staged ASD surgeries, efforts should be made to shorten the interval between ALIF and subsequent posterior fusion. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.