FEVAR pitch: 3D CT cuts radiation exposure

The complexity of fenestrated endovascular aortic repair (FEVAR) makes it a radiation hog, but it may not have to be that way. Using advanced imaging technology, one facility reduced FEVAR’s radiation exposure, contrast usage and procedure time significantly.

Michael M. McNally, MD, and colleagues at the vascular surgery and endovascular therapy division at the University of Florida College of Medicine in Gainesville, compared two imaging modalities by measuring radiation exposure in patients undergoing FEVAR at their facility. Before September 2013, physicians performed this complex procedure in a hybrid operating room with a fixed imaging ceiling-mounted single-plane system (Toshiba). After September 2013, their institution inaugurated a 3D fusion CT-capable hybrid operating room that included an Artis zee system (Siemens).

A total of 31 patients underwent FEVAR with 3D CT capability and 41 without CT capability.  Radiation exposure, fluoroscopy time and contrast use were all lower in the CT group compared with the no CT group. Patients in the CT vs. no CT groups had radiation exposure of 2,200 mGy vs. 5,000 mGy; fluoroscopy time of 55 minutes vs. 84 minutes; and overall contrast use of 34 mL vs. 86 mL.

These differences remained when they broke patients into subgroups of two-vessel fenestration and three- and four-vessel fenestration. Overall procedure time also was lower. In the three- and four-vessel fenestration group, for instance, the procedure time was 230 minutes with CT and 330 minutes without CT.

Inconsistent wearing of radiation badges meant they couldn’t make a valid assessment of radiation exposure to staff. “Although we were not able to reliably calculate the radiation dosage to the provider who performed these procedures, one may reasonably assume that the substantial reduction in radiation exposure to the patient also translated to decreased exposure to all health care providers participating in these repairs,” McNally et al wrote.

The CT group had a significantly lower body mass index than the no-CT group, which could have biased results. Also, the study involved a single surgeon and a single center, and other hospitals might have different experiences. Nonetheless, they proposed, using advanced imaging with FEVAR has the potential to improve patient safety.    

The study was published in the January issue of the Journal of Vascular Surgery.