Prolonged operative time significantly impacts on the incidence of complications in spinal surgery

In spinal surgery adverse events (AE) and surgical complications (SC) significantly affect patient's outcome and quality of life. The duration of surgery has been investigated in different surgical field as risk factor for complications. The aim of this study is to analyze the correlation between operative time and adverse events in spinal surgery. We retrospectively analyzed data collected prospectively in a cohort of 336 patients surgically treated for spinal diseases of oncological and degenerative origin in a single center, between January 2017 to January 2018. Demographics and clinical data were collected. Adverse events were classified using Spinal Adverse Events Severity System version 2 (SAVES-V2) capture system. Focusing on degenerative patients, bivariate analysis and univariate logistic regression were used to determine the association between operative time and complications. A total of 105/336 patients experienced an AE related to surgery, respectively 38% in the oncological group and 28% in the degenerative group. The average age at surgery was 60.3 years (SD 17.1) and the mean operative time was 164.8 ± 138 min. A total of 206 adverse events (30 intraoperative, 135 early postoperative and 41 late postoperative AEs) were recorded. Early post-operative complications accounted for the most recorded AEs (55.5% in the oncological group and 73.2% in the degenerative group). Univariate logistic regression analyses confirmed that operative time correlated with increased risk of intra-operative (p-value = 0.0008), early post-operative (p-value