The incidence of stroke among selected patients undergoing elective posterior lumbar fusion: a retrospective cohort study
Abstract Background: Although stroke is a rare complication among spinal surgery patients, the recognition of this adverse event is critical given the aging population undergoing surgical procedures. The objective of this study was to estimate the incidence of stroke among selected adults undergoing elective posterior lumbar fusion (PLF) during post-operative risk windows and among different subgroups.Methods: A retrospective cohort study using a longitudinal electronic healthcare record (EHR) database was conducted from January 1, 2007 to June 30, 2018. Elective PLF, stroke, and select clinical characteristics were defined based on International Classification of Disease codes. Patients aged 18 to 85 years with ≥ 183 days of enrollment in the database prior to undergoing elective PLF were followed from the index date until the occurrence of stroke, death, loss to follow-up, or end of study period, whichever occurred first. Incidence proportions (IPs) and rates (IRs) of stroke were estimated in the following risk windows: index hospitalization, ≤ 30 days, ≤ 90 days, ≤ 180 days, and ≤ 365 days post-operationResults: A total of 43,063 patients were eligible for the study. The IP of stroke following elective PLF ranged from 0.29% (95% confidence interval [CI]: 0.25%, 0.35%) during index hospitalization to 1.12% (95% CI: 1.03%, 1.23%) ≤ 365 days post-operation; the IR of stroke following elective PLF per 1000 person-years decreased consistently from 229.08 (95% CI: 192.38, 272.78) during index hospitalization to 13.68 (95% CI: 12.51, 14.96) ≤ 365 days post-operation. Stratified analyses revealed that older patients had a higher incidence of stroke. Additionally, black patients had higher stroke incidences. Post-operative stroke incidence was higher among patients with a history of type 2 diabetes than among patients without such history.Conclusions: The incidence of stroke following elective PLF using an EHR database in this study is slightly higher than that reported in the literature. Our results suggest that stroke risk modification prior to PLF may be important for patients who are older, black, type 2 diabetic, and/or have a history of stroke.