Scaling laws and the left main coronary artery bifurcation. A combination of geometric and simulation analyses.

The geometry of coronary arteries is believed to play the role as an atherosclerotic risk factor on its own. The full characterization of the normal coronary network has been reported in the literature. Reports on the integration of geometry and functional data for normal coronary vessels started to proliferate more recently. In this work, we analyze and integrate the geometric data retrieved from angiography images of the left main coronary bifurcation in angiographically normal patients and hemodynamic data generated from blood flow models to analyze the role of allometric laws and the connection between flow distribution and wall shear stress loads on the left anterior descending and left circumflex arteries. This in-silico study contributes to the characterization of normal coronary anatomy and its impact on the hemodynamic shear stresses acting over the vessel wall, shedding light on the impact of geometry-based versus simulation-based hypotheses to define boundary conditions for numerical simulations. We discuss the role of the wall shear stress corresponding to scenarios adopted by the scientific community and the ones proposed in this study. For the simulation-based hypothesis, we propose an iterative strategy to define boundary conditions at the main left coronary bifurcation, such that wall shear stresses are matched between the left descending and left circumflex arteries. From this study, we conclude that a one-fits-all power law exponent of 7/3 results in an good trade-off between computational cost and wall shear stress balance between daughter vessels.

Robotic-assisted intervention strategy to minimize air exposure during the procedure: a case report of myocardial infarction and COVID-19.

Percutaneous coronary interventions (PCI) is traditionally a manual procedure executed by one or more operators positioned at a close distance from the patient. The ongoing pandemic of coronavirus disease 2019 (COVID-19) has imposed severe restrictions to such an interventional environment. The novel SARS-CoV-2 virus that causes COVID-19 is transmitted mainly through expelled respiratory particles, which are known to travel approximately 3-6 feet away from infected persons. During PCI, that contamination range obligatorily poses the team and the patient to direct air exposure. We herein present a case report with the description of a minimum-contact strategy to reduce interpersonal air exposure during PCI. The approach designed to minimize proximity between the patient and the healthcare team included the performance of robotic-assisted PCI, operated by unscrubbed cardiac interventionalists from a control cockpit located outside the catheterization suite. Also included, was the delineation of the potential zone of respiratory particle spread; a circle measuring 4 meters (13.1 feet) in diameter was traced on the floor of the cath lab with red tape, centered on the patient's mouth and nose. The team was rigorously trained and advised to minimize time spent within the 4-meter perimeter as much as possible during the procedure. Following this strategy, a 60-year-old male with non-ST-elevation myocardial infarction and COVID-19 was treated with successful coronary implantation of two stents in the obtuse marginal branch and one stent in the circumflex artery. The total duration of the procedure was 103 minutes and 22 seconds. During most of the procedure, the 4-meter spread zone was not entered by any personnel. For each individual team member, the proposed strategy was effective in ensuring that they stayed outside of the 4-meter area for the majority of their work time, ranging from 96.9% to 59.7% of their respective participation. This case report illustrates the potential of robotic-assisted percutaneous coronary intervention in reducing physical proximity between the team and the patient during the procedure.