Dynamic Computed Tomography Angiography is More Accurate in Diagnosing Endoleaks than Standard Triphasic Computed Tomography Angiography and Enables Targeted Embolization

Abstract

The primary objective was to compare the accuracy of dynamic computed tomography (CT) angiography (d-CTA) with standardized triphasic contrast enhanced CT angiography (t-CTA) in diagnosing endoleak type after endovascular aortic repair (EVAR) using digital subtraction angiography (DSA) as reference standard. The secondary objective was to study the impact of d-CTA on image fusion-guided endoleak embolization. A retrospective review of patients who underwent d-CTA imaging after EVAR between March 2019 and July 2021 was performed. Deidentified images were independently reviewed by two-two blinded readers to document endoleak type and target vessels. An impact of d-CTA-guided embolization was evaluated by a number of planning angiograms, radiation exposure, and accuracy of target vessel overlay. During the study period, 52 patients underwent d-CTA and 19 had all 3 modalities available for analysis. DSA imaging confirmed 4 (21.0%) type-I, 14 (73.7%) type-II, and 1 (5.3%) type-III endoleak. Findings from d-CTA matched with DSA in 19/19 cases (100%), whereas t-CTA matched in 14/19 cases (73.7%). In type-II endoleaks, the number of target vessels identified by d-CTA, t-CTA, and DSA were 23, 17, and 16, respectively. Mean dose-length product from d-CTA and t-CTA was 1,445±551 and 1,612±530mGy × cm (P=0.26). Nine patients underwent d-CTA-guided type-II endoleak embolization, using a median of 1 (range: 1-4) planning angiogram before embolization using 21.6 (± 8.7)% of total procedural radiation dose. Target vessel overlay was accurate in 9/9 (100%) cases. Dynamic, time-resolved CTA is more accurate compared to standardized triphasic contrast enhanced CTA in diagnosing endoleak type after EVAR. In type-II endoleak, d-CTA better identified target vessels and enabled safe, targeted embolization.