Aims: To facilitate OCT images acquisition we developed a novel, simplified, non-occlusive technique based on manual infusion of a viscous isosmolar solution. The aims of the present study was to address the safety and efficacy of non-occlusive OCT images acquisition modality in a patient population with complex coronary lesions, and in various clinical scenarios. Methods and results: OCT assessment was performed with the LightLab OCT Imagewire™ in 64 patients. The imaging acquisition technique was aimed at target lesion and proximal and distal reference segments. OCT images were deemed of good quality if they allowed both an accurate measurement of luminal area and a qualitative classification of the superficial plaque components. In 60 patients (93.7%), the procedure was successful. The mean images acquisition time was 5.3±1.4 minutes. No major complications such as death, myocardial infarction or major arrhythmias were recorded. The average length of imaged segments was 28.6±6.1 mm and 95.1% of the imaged segments were deemed of sufficient quality to evaluate luminal area and plaque morphology (intra-observer and inter-observer variability 0.71, p<0.0001 and 0.68, p<0.0001 respectively). Conclusions. The non-occlusive modality of OCT image acquisition is safe and effective, and promises to simplify the complex current occlusive technique, leading to a marked reduction of procedural time.

OCT is a promising means for monitoring stent strut coverage and vessel wall healing in vivo, the relevance of which will become even more significant with the increasing use of drug-eluting stents.

Radial artery occlusion after percutaneous coronary procedures was not associated with a reduction in hand and finger strength.

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ptical coherence tomography (OCT), which is based on infrared light emission, is a novel intravascular imaging modality that enables high resolution imaging of the arterial wall, in the range of 10-20 . 1,2 This feature allows visualization of specific components of atherosclerotic plaque, similar to histology. 3,4 However, the need for blood displacement to obtain reliable images is associated with a challenging process of image acquisition. Presently, the technique most widely used involves a soft occlusion balloon and saline injection in the coronary artery to obtain a long pull-back or, alternatively, a saline bolus to image only the target lesion. [1][2][3][4][5][6] In either case the imaging procedure is still complex, time consuming and may lead to endothelial trauma from balloon inflation, 6 which limits its widespread clinical and research application. To overcome this limitation we have developed a simplified method for OCT image acquisition that does not require vessel occlusion. The hypothesis that guided our study is that a sufficient amount of fluid infused in the coronary artery could displace the blood for the time necessary to obtain clear OCT images of a tract of coronary artery in order to define the atherosclerotic plaque and a reference segment of the artery itself. The basic idea is that the fluid Circulation Journal Vol.72, May 2008needs a viscosity higher than that of blood and that the higher the viscosity of the fluid the lower the volume required. The fluid has to be safe and iso-osmotic, with the same electrolytic composition of blood, so as not to create myocyte membrane alterations. Accordingly, the present study was designed to test solutions in an animal model and then apply the results in clinical practice. Methods Experimental Study: Testing the SolutionsThe institutional Animal Care and Use Committee approved the study. All research was conducted in compliance with the Animal Welfare Act and other Italian and European Community statutes and regulation related to experiments involving animals. The study adhered to the principles stated in the Guide for the Care and Use of Laboratory Animals, National Research Council, 1996 edition. Strict aseptic technique was used for all surgical procedures.Three female swine (weight, 45-65 kg) were anesthetized with an intramuscular injection of ketamine (10 mg/kg) and inhaled isoflurane (4% to 5%). After insertion of endotracheal tubes, isoflurane was reduced to 0.5% or 1%. All animals were allowed to breathe spontaneously using a mixture of oxygen and air administered through a Narkomed M ventilator. The animals were placed in the supine position and a 12-lead electrocardiographic (ECG) monitoring was performed. The femoral artery was cannulated with a 6F introducer sheath using a cut-down technique. A 22G angiocatheter was inserted in the right carotid artery for continuous blood pressure monitoring. After systemic heparinization (50 U/kg), the right coronary artery (RCA) was cannulated Background Optical coherence tomography (OCT), a hi...