Optical coherence tomography (OCT), a high resolution intravascular imaging technique, requires blood displacement for reliable image acquisition and the current technique uses a soft occlusion balloon plus saline injection in the coronary artery. A non-occlusive technique based on manual infusion of a viscous iso-osmolar solution has been developed and tested and validated through a 2-phase study. OCT assessment was performed with the M2 LightLab OCT (LightLab Imaging, Westford, MA, USA) image-wire in 3 swine by infusing 30 ml of each of 3 solutions differing in viscosity, osmolarity and electrolytic composition (A: iodixanol 320 and Lactated Ringer's; B: iodixanol 320 and 50% albumin; C: iodixanol 320). Image quality and adverse effects were evaluated. The solution with the best image quality/side-effect ratio was tested in 44 patients. The best image quality/side-effect ratio was obtained in the swine model with solution C, which enabled the study of arterial segments of 29.8+/-2.1 mm in length. The results were confirmed in the human study (average length of 28.3+/-2.5 mm and absence of major complications and/or major arrhythmias). Repeated OCT pull-back in the first 10 patients enabled comparison of 1,572 matched cross-sections with an excellent correlation for reproducibility (R=0.96; p<0.001). The non-occlusive technique using iodixanol 320 has an excellent ratio of safety, feasibility and efficacy.

This study aimed to compare two commercially available off the shelf branched endografts for thoraco-abdominal aortic aneurysm (TAAA) repair, namely the E-nside (Artivion) and Zenith t-Branch (Cook Medical) devices. This multicentre retrospective study (2020 - 2023) included patients treated by branched endovascular aortic repair (BEVAR) for TAAA using the inner branched E-nside or the outer branched t-Branch. Endpoints were 30 day technical success and major adverse events (MAEs) as well as 1 year freedom from target vessel instability and main endograft instability. The study included 163 patients: 79 (307 target vessels) treated with E-nside and 84 (325 target vessels) with t-branch. Aneurysm extent was I - III in 91 patients (55.8%; 47% of E-nside and 66% of t-Branch) and IV in 72 patients (44.2%; 53% of E-nside and 34% of t-Branch) (p = .011). An adjunctive proximal thoracic endograft was used in 43% of E-nside vs. 69% of t-Branch (p < .001), with less frequent thoracic endografting (14% vs. 76%; p < .001) and shorter length of coverage (p = .024) in extent IV TAAA treated by E-nside. E-nside cases had shorter bridging length of renal arteries (66 ± 17 mm vs. 76 ± 20 mm; p < .010) and less frequent use of a distal bifurcated endograft (53% vs. 80%; p < .001). Comparing 30 day results, mortality was 1% vs. 2% (p = .62), any MAE occurred in 18% vs. 21% (p = .55), the stroke rate was 3% vs. 0% (p = .23), and the elective spinal cord ischaemia rate was 5% vs. 8% (p = .40) for E-nside and t-Branch, respectively. At 1 year, freedom from target vessel instability was 96 ± 3% for E-nside and 95 ± 3% for t-Branch (p = .58), and freedom from endograft instability was 98 ± 2% vs. 97 ± 3% (p = .46) respectively. Both off the shelf devices provided excellent early and 1 year results. The E-nside may require shorter thoracic aorta coverage and bridging length for the renal arteries, and less frequent implantation of concomitant proximal thoracic or distal abdominal bifurcated endograft. However, these aspects did not determine significant differences in clinical outcomes.