Establishment of a canine model of acute pulmonary embolism with definite right ventricular dysfunction through introduced autologous blood clots.

Abstract

PURPOSE: To establish a canine model of acute pulmonary embolism (PE) with right ventricular (RV) dysfunction using autologous blood clots and evaluate by echocardiography and contrast-enhanced Computed Tomography (CT). MATERIALS AND METHODS: Autologous blood clots formed in vitro were introduced sequentially into the pulmonary arteries of eight healthy mixed-breed dogs while monitoring pulmonary and systemic hemodynamic function. Blood clots were injected until the mean pulmonary artery pressure (MPAP) reached two-three times the baseline pressure, which was maintained up to 1 hour. The RV function was assessed by echocardiography and ECG-gated dual-source contrast CT. RESULTS: All animals survived the imaging procedure. The post-injection pulmonary angiograms showed extensive PE, and MPAP increased from 16.50&#xb1;2.45 mmHg to 43.13&#xb1;4.91 mmHg (P<0.001). On echocardiography, the RV fractional area change decreased from 42.06&#xb1;3.36 to 27.96&#xb1;3.54 (P<0.001), and the RV myocardial performance increased from 0.20&#xb1;0.05 to 0.63&#xb1;0.16 (P<0.001). On CT, the RV end-systolic volume increased from 11.11&#xb1;1.81 ml to 24.71&#xb1;4.60 ml (P<0.001), RV end-diastolic volume from 20.73&#xb1;2.83 ml to 34.63&#xb1;5.76 ml (P<0.001), and the four-chamber RV/left ventricular diameter ratio from 0.38&#xb1;0.07 to 0.81&#xb1;0.14 (P<0.001). CONCLUSION: Acute PE with RV dysfunction was established in a large animal model through controlled injection of autologous blood clots, which may be useful for developing and evaluating new therapeutic approaches for acute PE with RV dysfunction.