Development and Validation of an Ex-Vivo Porcine Model of Functional Tricuspid Regurgitation
Presented During:
Friday, May 5, 2023: 7:05AM - 7:10AM
New York Hilton Midtown
Posted Room Name:
Petit Trianon
Abstract No:
MO057
Submission Type:
Abstract Submission
Authors:
Hannah Rando (1), Emily Larson (1), Rachael Quinn (1), James Gammie (2)
Institutions:
(1) Johns Hopkins University, Baltimore, MD, (2) Johns Hopkins Hospital, Baltimore, MD
Submitting Author:
Hannah Rando
-
Contact Me
Johns Hopkins University
Johns Hopkins University
Co-Author(s):
Emily Larson
-
Contact Me
Johns Hopkins University
Johns Hopkins University
Rachael Quinn
-
Contact Me
Johns Hopkins University
Johns Hopkins University
*James Gammie
-
Contact Me
Johns Hopkins Hospital
Johns Hopkins Hospital
Presenting Author:
Emily Larson
-
Contact Me
N/A
N/A
Abstract:
Objective: Tricuspid annuloplasty is effective for the majority of patients with functional tricuspid regurgitation (FTR), but carries a risk of conduction abnormalities requiring permanent pacemaker, and is ineffective for a subset of patients with severe or torrential regurgitation. We are developing novel repair methods for FTR, and our objective was to create and validate an ex-vivo model to test these approaches.
Methods: In explanted porcine hearts, the right atrium was excised to visualize the tricuspid valve (TV). The pulmonary artery and aorta were clamped and cannulated, the coronary arteries ligated, and the right and left ventricles statically pressurized with air to 30 mmHg and 120 mmHg, respectively. FTR was induced by increasing right ventricular pressure to 80 mmHg for three hours, which resulted in progressive tricuspid annular enlargement, right ventricular dilation, papillary muscle displacement, and central tricuspid malcoaptation. A structured light scanner was used to image the 3D topography of the TV in both the native and FTR state, and images were exported into scan-to-CAD software which allowed for high-resolution 3D computational reconstruction. Relevant geometric measurements were sampled including annular circumference and area, major and minor axis diameter, and tenting height, angle, and area. Geometric measurements from the ex-vivo model were compared to clinical transthoracic echocardiographic (TTE) measurements using two-sample t-tests.
Results: Six porcine hearts were included. Measurements of the native valve were comparable to published TTE data (Table 1), with the exception of minor axis diameter, which was shorter in the ex-vivo model (2.9 vs 3.9 cm, p=0.010), and tenting angle, which was larger in the ex-vivo model (31° vs 22°, p=0.002). Induction of FTR in the ex-vivo model resulted in annular enlargement (FTR vs. native: circumference 13.7 vs.11.6 cm, p<0.001; area 14.7 vs.10.8 cm2, p<0.001) and leaflet tethering (tenting area 1.5 vs. 0.7 cm2, p<0.001). Geometric parameters in the FTR model were similar to published TTE data in the majority of cases, including annular circumference and area, major axis diameter, tenting height, tenting area, and effective regurgitant orifice area (EROA).
Conclusions: This ex-vivo pneumatically-pressurized porcine model closely models the geometry of both the native and regurgitant tricuspid valve complex in humans, and holds promise for testing novel FTR repair strategies.
Methods: In explanted porcine hearts, the right atrium was excised to visualize the tricuspid valve (TV). The pulmonary artery and aorta were clamped and cannulated, the coronary arteries ligated, and the right and left ventricles statically pressurized with air to 30 mmHg and 120 mmHg, respectively. FTR was induced by increasing right ventricular pressure to 80 mmHg for three hours, which resulted in progressive tricuspid annular enlargement, right ventricular dilation, papillary muscle displacement, and central tricuspid malcoaptation. A structured light scanner was used to image the 3D topography of the TV in both the native and FTR state, and images were exported into scan-to-CAD software which allowed for high-resolution 3D computational reconstruction. Relevant geometric measurements were sampled including annular circumference and area, major and minor axis diameter, and tenting height, angle, and area. Geometric measurements from the ex-vivo model were compared to clinical transthoracic echocardiographic (TTE) measurements using two-sample t-tests.
Results: Six porcine hearts were included. Measurements of the native valve were comparable to published TTE data (Table 1), with the exception of minor axis diameter, which was shorter in the ex-vivo model (2.9 vs 3.9 cm, p=0.010), and tenting angle, which was larger in the ex-vivo model (31° vs 22°, p=0.002). Induction of FTR in the ex-vivo model resulted in annular enlargement (FTR vs. native: circumference 13.7 vs.11.6 cm, p<0.001; area 14.7 vs.10.8 cm2, p<0.001) and leaflet tethering (tenting area 1.5 vs. 0.7 cm2, p<0.001). Geometric parameters in the FTR model were similar to published TTE data in the majority of cases, including annular circumference and area, major axis diameter, tenting height, tenting area, and effective regurgitant orifice area (EROA).
Conclusions: This ex-vivo pneumatically-pressurized porcine model closely models the geometry of both the native and regurgitant tricuspid valve complex in humans, and holds promise for testing novel FTR repair strategies.
Mitral Conclave:
Tricuspid Valve Diseases & Therapies
Image or Table
