H. Weissler1, K. Southerland1, S. Nag1, C. Long1, B. Gilmore1, M. Turner1, L. Olivere1, M. Cox1, C. Shortell1 1Duke University Medical Center,Vascular Surgery,Durham, NC, USA
Introduction: Fenestrated endovascular aortic aneurysm repair (FEVAR) has expanded the benefits of endovascular aortic aneurysm repair (EVAR) to a population of patients who would have otherwise been anatomically unfit for endovascular repair. However, FEVAR is associated with high radiation doses and contrast loads due to its increased complexity. Three-dimensional (3D) fusion computed tomography (CT) merges the preoperative CT with intraoperative imaging to create a vascular mask and has been shown to decrease radiation and contrast use during FEVAR. Currently available 3D fusion systems use hardware-based (i.e. operating table) tracking to position the overlay on the fluoroscopic image. This is labor intensive and often leads to inaccurate overlays. Our institution recently implemented a novel, cloud-based 3D fusion system which uses the patient’s vertebral anatomy rather than the operating table to register and create the overlay. This system has been shown in prior studies to be highly accurate and decrease radiation dose required for EVAR. The purpose of this study was to determine if radiation dose reduction during FEVAR would occur with this new 3D fusion strategy.
Methods:
Our institutional database was reviewed to identify patients who underwent elective FEVAR. Patients treated using our cloud-based 3D fusion software CT were compared to patients treated in the immediate 6 months prior to the implementation of 3D fusion CT. Primary end points included patient radiation exposure (mGy), contrast use (mL), and fluoroscopy and procedure times (minutes).
Results:
Thirty-three patients underwent FEVAR from October 2016 through June 2018, twenty prior to implementation of 3D fusion CT and thirteen after. There was no difference between these groups regarding demographics, BMI or comorbidities. Radiation dose was significantly decreased following 3D fusion CT implementation (5735 ± 2651 mGy versus 3503 ± 2422 mGy, p=0.019). In addition, there was a significant decrease in the number of FEVARs requiring a high radiation dose (> 2Gy) with 3D fusion CT (9 vs 19, p=0.044). There was no difference in fluoroscopy time (72.7 ± 16.9 minutes versus 62.9 ± 15.1 minutes, p=0.061), procedure time (257.6 ± 100.1 minutes versus 213.3 ± 41.1 minutes, p=0.118) and contrast volume (94.5 ± 34.7 mL versus 72.8 ± 37.8 mL, p=0.168) between the two groups.
Conclusions:
These results demonstrate that the use of an intraoperative image-based 3D fusion CT strategy based on the patient’s vertebral anatomy rather than hardware can significantly decrease radiation exposure during FEVAR. Endovascular solutions to aortic pathology will undoubtedly continue to expand; therefore radiation safety will be paramount. Image based 3D fusion CT has the potential to improve clinical and safety outcomes for both patients and providers.
