Implications of surgical infection on surgical and hospital outcomes after spine surgery: A NSQIP study of 410,930 patients

Study design

Retrospective cohort study.

Objectives

Surgical infections are unfortunately a fairly common occurrence in spine surgery, with rates reported as high as 16 %. However, there is a relative paucity of studies that look to understand how surgical infections may impact outcome variables. The aim of this study was to assess the impact of surgical infection on other perioperative complications, extended hospital length of stay (LOS), discharge disposition, and unplanned readmission following spine surgery.

Methods

A retrospective cohort study was performed using the 2016–2022 ACS NSQIP database. Adults receiving spine surgery for trauma, degenerative disease, and tumors were identified using CPT and ICD-9/10 codes. Patients were divided into two cohorts: surgical infection (superficial surgical site infection, deep surgical site infection, organ space surgical site infection, or wound dehiscence) and no surgical infection (those who did not experience any infection). Patient demographics, comorbidities, intraoperative variables, postoperative adverse events (AEs), and healthcare resource utilization were assessed. Multivariate logistic regression analysis was utilized to identify predictors of AEs, extended hospital length of stay, non-routine discharge, and unplanned readmission.

Results

In our cohort of 410,930 patients, 7854 (2.2 %) were found to have experienced a surgical infection. Regarding preoperative variables, a greater proportion of the surgical infection cohort was a female (p < 0.001) and had a higher mean BMI (p < 0.001), greater frailty and ASA scores (p < 0.001), and higher rates of all presenting comorbidities included in the study. Rates of AEs (p < 0.001), unplanned readmission (p < 0.001), reoperation (p < 0.001), non-home discharge (p < 0.001), and 30-day mortality were all greater in the surgical infection group when compared to the group without surgical infection. On multivariate analysis, surgical infection was found to be an independent predictor of experiencing postoperative complications [aOR: 6.15, 95 % CI: (5.72, 6.60), p < 0.001], prolonged LOS [2.71, 95 % CI: (2.54, 2.89), p < 0.001], non-routine discharge [aOR: 1.74, 95 % CI: (1.61, 1.88), p < 0.001], and unplanned readmission [aOR: 22.57, 95 % CI: (21.06, 24.19), p < 0.001].

Conclusions

Our study found that surgical infection increases the risk of complications, extended LOS, non-routine discharge, and unplanned readmission. Such findings warrant further studies that aim to validate these results and identify risk factors for surgical infections.