Complications Following Minimally Invasive Transforaminal Lumbar Interbody Fusion: Incidence, Independent Risk Factors, and Clinical Impact.

STUDY DESIGN: This was a retrospective study. OBJECTIVE: The objective of this study was to determine the incidence and risk factors for postoperative complications following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). SUMMARY OF BACKGROUND DATA: The identification of independent risk factors that predispose patients to postoperative complications following MIS TLIF may allow for improved outcomes and the optimization of modifiable conditions before surgical intervention. MATERIALS AND METHODS: Patients undergoing a single-level MIS TLIF were retrospectively reviewed. Demographic information and the presence of baseline medical conditions was recorded for all patients. Postsurgical complications that arose following the MIS TLIF procedure were recorded. The incidence of postoperative complications was tested for association with patient and surgical characteristics using bivariate Poisson regression. Independent risk factors for complications were identified through a backward stepwise regression model. RESULTS: A total of 421 patients who underwent a primary, single-level MIS TLIF procedure were included in our analysis. The most common complication was urinary retention requiring catheterization (n=43, 10.2%), followed by pseudarthrosis (n=37, 8.8%), and then altered mental status (n=11, 2.6%). Multivariate analysis was conducted to determine the independent risk factors predictive of complications. The significant factors were obesity status (relative risk=2.2, P=0.001), the presence of diabetes (relative risk=2.6, P=0.002), and operative duration >105 minutes (relative risk=2.5, P=0.008). CONCLUSIONS: The present study provides the incidence of complications following MIS TLIF, as well as risk factors that are predictive of complications that may arise following the procedure. Independent variables for increased complication rates included extended operative duration, obesity, and diabetes status. The identification of these factors may be clinically useful to spine surgeons in terms of preoperative discussion and planning.