The field of three-dimensional printing applied to patient-specific simulation is evolving as a tool to enhance intervention results. We report the first case of a fully simulated percutaneous coronary intervention in a three-dimensional patient-specific model to guide treatment. An 85-year-old female presented with symptomatic in-stent restenosis in the ostial circumflex and was scheduled for percutaneous coronary intervention. Considering the complexity of the anatomy, patient setting and intervention technique, we elected to replicate the coronary anatomy using a three-dimensional model. In this way, we simulated the intervention procedure beforehand in the catheterization laboratory using standard materials. The procedure was guided by optical coherence tomography, with pre-dilatation of the lesion, implantation of a single drug-eluting stent in the ostial circumflex and kissing balloon inflation to the left anterior descending artery and circumflex. Procedural steps were replicated in the real patient's treatment, with remarkable parallelism in angiographic outcome and luminal gain at intracoronary imaging. In this proof-of-concept report, we show that patient-specific simulation is feasible to guide the treatment strategy of complex coronary artery disease. It enables the surgical team to plan and practice the procedure beforehand, and possibly predict complications and gain confidence.
24 December 2016 in The International Journal of Cardiovascular Imaging
The flavonoids (-)-epigallocatechin-3-gallate (EGCg) and (-)-epicatechin-3-gallate (ECg) are major components of green tea and show numerous biological effects. We investigated the glucuronidation of these compounds and of quercetin by microsomes. Quercetin was almost fully glucuronidated by liver microsomes after 3 h, whereas ECg and ECGg were conjugated to a lesser extent ([Formula: See Text] and [Formula: See Text] respectively). The intestinal microsomes also glucuronidated quercetin much more efficiently than ECg and EGCg. Although the rates were lower than quercetin, intestinal microsomes exhibited higher activity on the galloyl group of ECg and EGCg compared to the flavonoid ring, whereas hepatic glucuronidation was higher on the flavonoid ring of EGCg and ECg compared to the galloyl groups. The low glucuronidation rates could partially explain why these flavanols are present in plasma as unconjugated forms.
Atrial fibrillation (AF) is a common cardiac arrhythmia characterized by irregular and rapid electrical activity in the atria, leading to ineffective contraction and poor blood flow. More than 90% of the left atrial (LA) thrombi that cause thromboembolic events during atrial fibrillation (AF) develop in the left atrial appendage (LAA). AF modifies the hemodynamics of the left atrium, which can result in thrombosis of the LAA, systemic embolism, and stroke. The current options to reduce thromboembolic events are oral anticoagulation, surgical LAA exclusion, or percutaneous LAA occlusion. However, the mechanism underlying thrombus development in the LAA remains poorly understood. Computational fluid dynamics (CFD) analysis can be used to better understand the risk of thrombus formation and subsequent embolic events. CFD enables the simulation and visualization of blood flow patterns within the heart, including complex structures such as the LAA. Using CFD, researchers can analyze the hemodynamics of blood flow, identify areas of stagnation or turbulence, and predict the risk of thrombus formation. The correlation between blood flow dynamics, atrial fibrillation, and the risk of stroke has been highlighted by CFD studies investigating the underlying mechanism of thrombus formation in the LAA. This review study intends to provide a comprehensive overview of the factors involved in thrombus formation and their implications for clinical practice by synthesizing the insights acquired from these CFD studies.