P38. Intraoperative 3D navigation versus fluoroscopy: a comparison of time-demand, radiation exposure and outcomes in minimally invasive transforaminal lumbar interbody fusion (MI-TLIF)

Abstract

BACKGROUND CONTEXT Real time image-guidance and intra-operative 3-dimensional navigation (ION), which utilize either a bone- or skin-anchored tracker, are increasingly being utilized in spine surgery to provide better visualization of abnormal anatomy, improve accuracy and enable less invasive procedures. However, ION is also associated with considerable upfront costs, intra-operative time-demand and potentially greater radiation exposure. PURPOSE To compare the time demand, radiation exposure and outcomes of 3D ION using a skin-anchored tracker (Stryker SpineMap 3D Navigation System, Stryker SpineMask Tracker) and conventional 2D fluoroscopy in Minimally Invasive Transforaminal Lumbar Interbody Fusion (MI-TLIF). STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE All patients who underwent single-level MI-TLIF by a single surgeon between 2011 and 2018. OUTCOME MEASURES Operative time, fluoroscopy time and radiation dose. METHODS Demographics, operative factors and radiation exposure were compared using chi square test for categorical, and independent sample t-test and median t-test for normally and non-normally distributed continuous variables, respectively. RESULTS Of the 169 patients in this study, 94 underwent MI-TLIF using fluoroscopy and 75 using skin-based ION. There were no significant differences in demographics (age:p=0.632; sex:p=0.877, BMI:p=0.732) or level of surgery (p=0.614), with L4-L5 being the most common level in both cohorts. The time required for ION set-up, measured as the time taken from completion of anesthesia induction to the start of the surgical procedure was a median of 24 minutes [IQR 21–28]. This accounts for the time required for patient positioning, preparing and draping the incision site, placing the skin-anchored navigation tracker and acquiring a three-dimensional image for real-time navigation. The use of ION resulted in significantly shorter operative times (median 92 minutes [IQR 77–101] vs 108 [IQR 95–124.5] for fluoroscopy, p CONCLUSIONS The results of our study show that the use of intra-operative navigation using a skin-anchored navigation tracker is a feasible, safe and accurate approach that does not increase the total time-demand of the surgery. In addition, intra-operative navigation was advantageous in terms of shorter operative times, reduced fluoroscopy time and lower total radiation exposure compared to traditional fluoroscopy. FDA DEVICE/DRUG STATUS Stryker SpineMap 3D Navigation System, Stryker SpineMask Tracker (Approved for this indication)