From bench to bedside: a novel technique of acquiring OCT images.

Background: 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.

Methods And Results: 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).

Conclusions: The non-occlusive technique using iodixanol 320 has an excellent ratio of safety, feasibility and efficacy.