Laser Imaging: Unraveling Laser Atherectomy Mechanisms of Action with Optical Coherence Tomography

Purpose of Review: The goal is to review the current data regarding excimer laser coronary atherectomy (ELCA) through optical coherence tomography (OCT) imaging. We aim to reveal the mechanisms of action and principles of use for laser, and to analyze the current supportive data. Recent Findings: ELCA is an adjuvant procedure to percutaneous coronary intervention, aimed at properly preparing coronary lesions to optimize stenting. It is an effective atherectomy device that requires a short period of training and works on a standard 0.014″ guidewire. Laser modifies coronary vessels by three distinct mechanisms: photoablation, chemoablation and thermoablation. Accordingly, it plays an important role in the management of lesions that require appropriate debulking, such as in-stent restenosis, chronic coronary occlusions (chronic total occlusion), stent underexpansion, and non-crossable/non-expandable lesions. Summary: OCT imaging of ELCA demonstrates that the most important mechanism of action is tissue debulking, facilitating pressure delivery to the vessel and tissue compression. In addition, laser light pulses weaken the connection between tissues, facilitating expansion. With combined laser use and OCT guidance, procedures may be properly planned to maximize final lumen gain and decrease predictors of restenosis.