VESS24 - Role of Intravascular Ultrasound for In Situ Sizing and Technical Assessment of Directional Branches During Branched Endovascular Aortic Repair

Objectives: to compare intraoperative and early outcomes of branched endovascular aortic repair (BEVAR) of thoracoabdominal aortic aneurysms (TAAA) with or without the use of intravascular ultrasound (IVUS).

Methods: we conducted a single-center retrospective study on consecutive patients treated for TAAA with branched devices (2019-2021). Two groups were compared: in standard BEVAR (s-BEVAR), sizing was based exclusively on the preoperative computed tomography angiogram (CTA), and the technical assessment consisted in intraoperative angiography. From 2020 (iv-BEVAR), IVUS (Philips platform with 0.035’ Volcano IVUS catheter) was routinely used for in-situ sizing of the bridging stent (diameter and length of the distal landing zone, total bridging stent length) and for the technical assessment of the bridging stent after deployment (kink, compression, malapposition, or inadequate sealing).
S-BEVAR and iv-BEVAR patients were compared in terms of procedural metrics (duration of surgery, radiation dose, radiation time, and contrast volume), technical success (successful introduction and deployment of the device and bridging stents, in the absence of surgical conversion or mortality, type I or type III endoleak, branch occlusion, or graft limb obstruction), and 30-days outcomes.

Results: There were 59 target vessels (n=15 patients) in the s-BEVAR group and 56 (n=15 patients) in the iv-BEVAR group. Aneurysm anatomical classification was similar (Extent I-III: 73% vs 67%; Extent IV: 27% vs 33%; P=.999). Comparing s-BEVAR vs iv-BEVAR, total operating time (280±62 min vs 293±84 min; P=.073) and contrast volume (168±42 ml vs 153±38 ml; P=.312) were similar, while iv-BEVAR had a lower radiation time (119±35 min vs 92±42 min; P=.042) and dose (745±75 Gy vs 635±85 Gy; P=.010). The use of IVUS identified a significant branch technical defect in 8/56 target vessels (14%) not identified with the standard angiography; bridging stent compression in 5 cases and incomplete stent-to-wall apposition in 3. These were all intraoperatively corrected with success. Technical success was 100% for both groups and there were no post-operative deaths and no IVUS-related complications. At 30 days there were no complications related to the main endograft or directional branches.

Conclusions: the use of IVUS for in-situ sizing and technical assessment of BEVAR was safe, and allowed to reduce radiation time and exposure during BEVAR, maintaining a similar operating time. In comparison to the sole angiography, the intraoperative use of IVUS led to adjunctive intraoperative maneuvers in a non-negligible portion of target vessels. Further studies are needed to evaluate the clinical role of IVUS in BEVAR.