RS26 - Cone-beam computed tomography during fenestrated endovascular aortic repair avoids a significant number of structural defects that would otherwise demand reinterventions

Objectives: Structural defects during fenestrated endovascular aortic repair (FEVAR) can be difficult to identify on the completion angiography. This study aims to assess the potential value of routine intraoperative completion cone-beam computed tomography (CBCT) during FEVAR.

Methods: A retrospective review of all consecutive FEVARs performed at a tertiary aortic center between January 2013 and January 2023. Patients with intraoperative plain CBCT and postoperative CTA were selected. Baseline characteristics, operative data and follow-up data were collected. Endpoints included intraoperative adjunctive procedures and early secondary reinterventions due to structural defects. These were analyzed by type, frequency and indication (CBCT, first postoperative CTA or symptoms). Data is presented as mean ± SD or Median (IQR) depending on the normality of the distribution.

Results: Total of 269 patients were treated by FEVAR during the study period. Of these, 233 were included (195 male, 72  6 years old, 218 (92%) elective repairs). A median (IQR) of 4 (3-4) fenestrations were incorporated into the main body.
In 39 patients (17%), 44 adjunctive intraoperative procedures were needed due to structural defect based on CBCT with renal bridging stent compression being the most common (n=21, 49%). All structural defects treated intraoperatively are listed in Table I. Overall technical success was achieved in 200 patients (86%).
All patient had at least 1 follow-up CTA. Secondary reintervention was performed in 11 patients (5%) for 14 structural defects. Renal stent compression was once more the most common indication for reintervention (n=8). All the defects treated postoperatively are listed in Table 2. All these defects went unnoticed during the intraoperative review of the CBCT. In 4 instances the image quality was insufficient, while in the remaining 7 patients the finding was visible but went unidentified at the time of the FEVAR. There were two clinical implications of the 11 missed defects. One patient had renal stent occlusion and another developed claudication due to limb stenosis. Both these were successfully corrected.
None of the patients with an intraoperative adjunctive procedure based on CBCT needed reintervention postoperatively due to structural defect.

Conclusions: The use of an intraoperative plain CBCT allows the identification of a significant number of structural defects that can be corrected immediately, avoiding reinterventions. There is a small number of visible findings on the CBCT that went unnoticed requiring reinterventions, underlining the need of a careful review of the imaging.