invasive-hemodynamic-assessment-for-right-ventricular-system-hypoxia

Invasive Hemodynamic Assessment for the Right Ventricular System and Hypoxia-Induced Pulmonary Arterial Hypertension in Mice

Pulmonary arterial hypertension (PAH) is a chronic and severe cardiopulmonary disorder. Mice are a popular animal model used to mimic this disease. ...

Chinese Academy of Medical Sciences and Peking Union Medical College

The tip structure is one of the key factors to determine the performance of left ventricular assist device (LVAD) inflow cannulas. The tip structure influences the thrombosis, hemolysis in cannula and left ventricle and suction leading to obstruction in ventricle. We designed four kinds of inflow cannulas that had different tips and built the numerical models of the four historical used inflow cannulas inserted into the apex of left ventricle. We computed the hemodynamic characteristics of inflow cannulas insertion by Fluent software. We researched the backflow, turbulent flow and pressure distribution of the four inflow cannulas. The results showed that the trumpet tipped inflow cannula had smooth flow velocity distribution without backflow or low velocity flow. The trumpet tipped inflow cannula had the best blood compatibility characteristics. The trumpet structure could prevent obstruction. The caged tipped cannula had serious turbulent flow which could possibly cause thrombosis and the low pressure near left ventricle wall and easily lead to ventricle collapse. The trumpet tipped inflow cannula has the best blood compatibility and is difficult to be obstructed. The trumpet tipped inflow cannula is fit to long-term use LVAD.

[Numerical simulation of LVAD inflow cannulas with different tips].

To evaluate a new transapical system which utilizes a novel designed positioning element and a two-step positioning mechanism for easy and accurate implantation of transcatheter valves.

Transapical implantation of a self-expandable aortic valve prosthesis utilizing a novel designed positioning element.

Existing simulators for off-pump coronary artery (CA) bypass grafting training are unable to provide cardiac surgery residents all necessary skills they need entering the operation room. In this study, we introduced a secure and high-fidelity live animal model to supplement the in vitro simulators for off-pump CA bypass grafting training.

A Secure and High-Fidelity Live Animal Model for Off-Pump Coronary Bypass Surgery Training.

The porcine mitral regurgitation (MR) model is a common cardiovascular animal model. Standardized manufacturing processes can improve the uniformity and success rate of the model, and systematic research can evaluate its potential use. In this study, 17 pigs were divided into an experimental group (n=11) and a control group (n=6). We used a homemade retractor to cut the mitral chordae via the left atrial appendage to establish a model of MR; the control group underwent a sham surgery. The model animals were followed for 30 months after the surgery. Enlargement and fibrosis of the left atrium were significant in the experimental group compared with those in the control group, and left atrial systolic function decreased significantly. In addition, model animals showed preserved left ventricular systolic function. There were no differences in left atrial potential or left ventricular myocardial fibrosis between the two groups. Atrial fibrillation susceptibility in the experimental group was higher than that in the control group. Our method enables the simple and effective production of a MR model with severe reflux that can be used for pathophysiological studies of MR, as well as for the development of preclinical surgical instruments and their evaluation. This model could also be used to study atrial fibrillation and myocardial fibrosis but is not suitable for studies of heart failure.

The characteristics of a porcine mitral regurgitation model.

Services for the preclinical development and evaluation of cardiovascular implant devices (CVIDs) is a new industry. However, there is still no indicator system for quality evaluation. Our aim is to construct a service for quality evaluation system for the preclinical research and development of CVIDs based on Fuzzy Analytical Hierarchy Process (FAHP).

Construction and application of service quality evaluation system in the preclinical research on cardiovascular implant devices.

The mechanism by which atrial fibrosis leads to the production and maintenance of atrial fibrillation (AF) is unclear. Myocardial biopsies, which have often been used in previous studies, are taken from a single site and do not always reflect the overall condition of atrial fibrosis.

Effects of atrial fibrosis induced by mitral regurgitation on atrial electrophysiology and susceptibility to atrial fibrillation in pigs.

There is still no satisfactory large-animal model of ischemic heart failure (IHF) with ideal survival rate and model time. The aim of this study is to explore a novel chronic IHF model in swine. 23 healthy Ba-Ma miniature pigs were included. Pigs in the experimental group underwent multiple strategic ligations on side branches of the left anterior descending (LAD) and circumflex coronary arteries. One week later, sequential intervention occlusion of the distal end of the LAD trunk was performed. In the experimental groups, LV end-diastolic (LVEDV) and end-systolic volume (LVESV) gradually increased starting at 4 weeks post operation. At 12 WPO, LVEDV increased from 45.0 ± 2.9 ml at baseline to 110.0 ± 9.8 ml and LVESV increased from 17.0 ± 1.4 ml at baseline to 42.0 ± 3.6 ml. Meanwhile, left ventricular ejection fraction significantly decreased from 73.8 ± 4.2 % at baseline to 31.0 ± 2.5%. According to histomorphometric assessment, viable cells were observed in infarction lesions, indicating the model has replicated the structural and functional features of chronic IHF.

Structural, functional and histological features of a novel ischemic heart failure model.

A "boot camp" program is commonly adopted in surgical skills training. Due to a shortage of cardiac surgeons, establishment of a well-designed training curriculum for cardiac surgery residents is needed in developing countries.

Article	Year
[Numerical simulation of LVAD inflow cannulas with different tips]. Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi\| PubMed ID: 23488155	2013
Transapical implantation of a self-expandable aortic valve prosthesis utilizing a novel designed positioning element. Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions\| PubMed ID: 26811261	2017
A Secure and High-Fidelity Live Animal Model for Off-Pump Coronary Bypass Surgery Training. Journal of surgical education\| PubMed ID: 27168385	2016
The characteristics of a porcine mitral regurgitation model. Experimental animals\| PubMed ID: 29794373	2018
Construction and application of service quality evaluation system in the preclinical research on cardiovascular implant devices. BMC medical informatics and decision making\| PubMed ID: 30819177	2019
Effects of atrial fibrosis induced by mitral regurgitation on atrial electrophysiology and susceptibility to atrial fibrillation in pigs. Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology\| PubMed ID: 30836303	2019
Structural, functional and histological features of a novel ischemic heart failure model. Frontiers in bioscience (Landmark edition)\| PubMed ID: 30844708	2019
An exploration of the surgical skill training curriculum for cardiac surgery residents. Journal of cardiac surgery\| PubMed ID: 30998835	2019

Fuliang Luo

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