Pierre Olivier Dionne1, Evan Wener2, Alexander Emmott2, Raymond Cartier1, Rosaire Mongrain3, Richard Leask2, Ismail El-Hamamsy4. 1. Division of Cardiac Surgery, Montreal Heart Institute and Université de Montréal, Montreal, Canada. 2. Department of Chemical Engineering, McGill University, Montreal, QC, Canada. 3. Department of Mechanical Engineering, McGill University, Montreal, QC, Canada. 4. Division of Cardiac Surgery, Montreal Heart Institute and Université de Montréal, Montreal, Canada i.elhamamsy@icm-mhi.org.
Abstract
OBJECTIVES: The aim of this study is to determine whether patients undergoing the Ross procedure with bicuspid aortic valves have pulmonary artery biomechanical properties different from those with tricuspid valves. METHODS: Thirty-two pulmonary arteries and 20 aortas were obtained from patients undergoing the Ross procedure at the time of surgery, from a cohort of 32 patients. The aortic valve was tricuspid in 5 patients (16%), bicuspid in 18 patients (56%) and unicuspid in 9 patients (28%). Histological analysis and ex vivo equi-biaxial tensile testing completed within 8 hours of surgery were used to evaluate differences in patient groups and between the pulmonary artery and the ascending aorta. RESULTS: There was no difference in thickness among pulmonary arteries when compared according to aortic valve phenotype (P = 0.94). There was no difference in the tensile tissue properties among aortas and pulmonary arteries when compared according to aortic valve phenotype, in either the circumferential or longitudinal axis. When compared according to the main surgical indication, pulmonary artery walls from patients with pure aortic regurgitation were less stiff than their counterparts (aortic regurgitation: 0.055 ± 0.037 MPa, aortic stenosis: 0.103 ± 0.051 MPa, mixed disease: 0.110 ± 0.044 MPa and aortic valve endocarditis: 0.216 ± 0.033 MPa, P = 0.002). There was no difference in the number of elastic lamellae in pulmonary artery specimens from the three different aortic valve phenotypes, as well as in the aortic specimens. CONCLUSIONS: No significant differences were observed in the biomechanical properties of pulmonary arteries when compared according to aortic valve phenotype.
OBJECTIVES: The aim of this study is to determine whether patients undergoing the Ross procedure with bicuspid aortic valves have pulmonary artery biomechanical properties different from those with tricuspid valves. METHODS: Thirty-two pulmonary arteries and 20 aortas were obtained from patients undergoing the Ross procedure at the time of surgery, from a cohort of 32 patients. The aortic valve was tricuspid in 5 patients (16%), bicuspid in 18 patients (56%) and unicuspid in 9 patients (28%). Histological analysis and ex vivo equi-biaxial tensile testing completed within 8 hours of surgery were used to evaluate differences in patient groups and between the pulmonary artery and the ascending aorta. RESULTS: There was no difference in thickness among pulmonary arteries when compared according to aortic valve phenotype (P = 0.94). There was no difference in the tensile tissue properties among aortas and pulmonary arteries when compared according to aortic valve phenotype, in either the circumferential or longitudinal axis. When compared according to the main surgical indication, pulmonary artery walls from patients with pure aortic regurgitation were less stiff than their counterparts (aortic regurgitation: 0.055 ± 0.037 MPa, aortic stenosis: 0.103 ± 0.051 MPa, mixed disease: 0.110 ± 0.044 MPa and aortic valve endocarditis: 0.216 ± 0.033 MPa, P = 0.002). There was no difference in the number of elastic lamellae in pulmonary artery specimens from the three different aortic valve phenotypes, as well as in the aortic specimens. CONCLUSIONS: No significant differences were observed in the biomechanical properties of pulmonary arteries when compared according to aortic valve phenotype.
Authors: Lucas Van Hoof; Peter Verbrugghe; Elizabeth A V Jones; Jay D Humphrey; Stefan Janssens; Nele Famaey; Filip Rega Journal: Front Cardiovasc Med Date: 2022-02-09