The authors thank the team at the Laboratory of Surgical Research, Marie Lannelongue Hospital, for technical assistance and animal care. The VividE9 cardiac ultrasound system (General Electric Medical System) was financed by a grant from the Cardio-vasculaire-Ob&#233;sit&#233; Domaine D&#39;Int&#233;r&#234;t Majeur (CODDIM cod 100158, R&#233;gionIle-de-France, France).

This protocol was approved by the local ethics committee on animal experiments and by the Institutional Committee on Animal Welfare of our institution. All animals received humane care in compliance with the &#8220;Principles of Laboratory Animal Care&#8221; formulated by the National Society for Medical Research and the &#8220;Guide for the Care and Use of Laboratory Animals&#8221; prepared by the Institute of Laboratory Animal Resources and published by the National Institutes of Health (NIH Publication No. 86-23, revi...

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As in human clinical practice, respect of asepsis rules is mandatory during all surgical procedures. In the original CTEPH piglet model described by O. Mercier et al., the left pulmonary artery ligation was performed after opening the pericardium, through a median sternotomy14. Because the pericardium was left opened, the interaction between the right ventricle and the pericardium was impaired and right heart failure was delayed. Adverse effect of RV enlargement on cardiac output has been demonstrated...

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) is a subtype of Pulmonary Hypertension (PH) due to chronic pulmonary vascular bed obstruction by persistent and organized clots related to one or more acute pulmonary embolisms1-3. A combination of obstructive and non-obstructive microvascular disease leads to an additional increase in pulmonary vascular resistance4. The right ventricle must first adapt with compensated hypertrophy to maintain the cardiac output. Without treatment, the right ventricle dilates and fails over time. In the modern era, PH remains a progressive and often fatal disease despite the use of modern targeted therapies5. Many studies have shown that right ventricular (RV) adaptation to pressure overload is the main determinant of survival in PH patients. For that reason, understanding the mechanisms underlying the transition from adaptive to maladaptive RV remodeling is a keystone for treatment and development of new therapies. Because PH is rare and tissue sampling is almost infeasible in these frail patients, experimental studies are required. Furthermore, preclinical studies are mandatory to ascertain that a drug with benefit in the pulmonary vasculature does not cause RV impairment.
For many years, different experimental models of PH and RV failure have been developed with advantages and limitations6,7. In the pharmacological murine models (Monocrotaline, SU5416, Hypoxia), PH and RV failure occur secondary to a massive inflammation, ischemia or toxic stressor that might induce several &#8220;sides effects&#8221; and bias in molecular pathway analysis. Furthemore, RV endomyocardial biopsies in a murine model should be very challenging without sacrifying the animal. Surgical models in larger animals are more physiological but do not affect the pulmonary vasculature (pulmonary artery banding, systemic-to-pulmonary shunt) or induce acute PH and RVF (acute pulmonary embolism). The aim of this article is to describe an original model of CTEPH in piglet that is more representative of CTEPH pathophysiology. This large animal model enables repeated noninvasive and invasive measurements usually performed in clinical practice (right heart catheterization) to follow changes in pulmonary hemodynamics and RV function.

chronic thromboembolic pulmonary hypertension and assessment of right ventricular function in the piglet

An original piglet model of Chronic Thromboembolic Pulmonary Hypertension (CTEPH) associated with chronic Right Ventricular (RV) dysfunction is described. Pulmonary Hypertension (PH) was induced in 3-week-old piglets by a progressive obstruction of the pulmonary vascular bed. A ligation of the left Pulmonary Artery (PA) was performed first through a mini-thoracotomy. Second, weekly embolizations of the right lower pulmonary lobe were done under fluoroscopic guidance with n-butyl-2-cyanoacrylate during 5 weeks. Mean Pulmonary Arterial Pressure (mPAP) measured by ritght heart catheterism, increased progressively, as well as Right Atrial pressure and Pulmonary Vascular Resistances (PVR) after 5 weeks compared to sham animals. Right Ventricular (RV) structural and functional remodeling were assessed by transthoracic echocardiography (RV diameters, RV wall thickness, RV systolic function). RV elastance and RV-pulmonary coupling were assessed by Pressure-Volume Loops (PVL) analysis with conductance method. Histologic study of the lung and the right ventricle were also performed. Molecular analyses on RV fresh tissues could be performed through repeated transcutaneous endomyocardial biopsies. Pulmonary microvascular disease in obstructed and unobstructed territories was studied from lung biopsies using molecular analyses and pathology. Furthermore, the reliability and the reproducibility was associated with a range of PH severity in animals. Most aspects of the human CTEPH disease were reproduced in this model, which allows new perspectives for the understanding of the underlying mechanisms (mitochondria, inflammation) and new therapeutic approaches (targeted, cellular or gene therapies) of the overloaded right ventricle but also pulmonary microvascular disease.

Feasability
This piglet model of chronic post-embolic pulmonary hypertension has been established in our laboratory in 2009-2010. Since 2011, we used 70 piglets and we performed 63 completed models. In our experience, the realization of this model required a learning curve.&#160;
Regarding the mortality, we observed 5 unplanned deaths (7.1%), mainly in the first part of our experience. The two critical steps were first, the pulmonary embolization and s...

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Chronic Thromboembolic Pulmonary Hypertension and Assessment of Right Ventricular Function in the Piglet

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) and Right Ventricular (RV) dysfunction were induced in piglets by progressive obstruction of the pulmonary arteries. Consequences were remarkably similar to those observed in CTEPH patients. This animal model would be a very useful tool for pathophysiology and therapeutic experiments on CTEPH and RV failure.

An original piglet model of Chronic Thromboembolic Pulmonary Hypertension (CTEPH) associated with chronic Right Ventricular (RV) dysfunction is described. ...

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12.1K visualizações.  Marie Lannelongue Hospital. Chronic Thromboembolic Pulmonary Hypertension (CTEPH) and Right Ventricular (RV) dysfunction were induced in piglets by progressive obstruction of the pulmonary arteries. Consequences were remarkably similar to those observed in CTEPH patients. This animal model would be a very useful tool for pathophysiology and therapeutic experiments on CTEPH and RV failure.