Purpose: To evaluate the feasibility of intraoperative 3-dimensional rotational angiography (DynaCT) as a single tool to assess suitability for endovascular aneurysm repair (EVAR) and for sizing the stent-graft.
Methods: Twenty elective patients undergoing EVAR were prospectively recruited. All had preoperative multidetector computed tomography (CT) scans and intraoperative (pre-stent deployment) DynaCT scans. Images were read independently by 4 experienced endovascular practitioners. A total of 17 morphological variables, including aneurysm neck diameter and length, were measured from the CT and DynaCT images and compared. Bland-Altman plots examined intraclass correlation of continuous outcomes; kappa correlation coefficient assessed agreement of ordinal results.
Results: The mean DynaCT radiation dose was 3751+/-835 microGym(2). The mean difference between DynaCT and multidetector CT in aneurysm neck diameter measurement was -1.5 mm (95% CI -4.9 to 1.9). Differences in left and right common iliac artery diameters were -1.9 mm (95% CI -6.3 to 2.4) and -2.1 mm (95% CI -6.9 to 2.7), respectively. For presence of neck thrombus, the group kappa statistic was 0.51 (p<0.0001); for neck calcification, the kappa was 0.07 (p = 0.29). Nine (45%) cases had incomplete information on DynaCT because external iliac arteries were not included in the scan.
Conclusion: DynaCT provides adequate preoperative imaging for morphological assessment of aortic anatomy. The greatest limitation is the evaluation of access vessels and underestimation of calcification. Due to current limited detector size, precise positioning is essential to attain all necessary sizing information using DynaCT.