Quantitative approach to aortic valve-sparing surgery.

Our goal was to understand why it is difficult to achieve reliable valve competence after aortic valve-sparing surgery, and to propose quantitative data aimed at improving the outcome of the procedure. Valve-sparing procedures were performed in patients with dilated aortic roots and aortic regurgitation, and reproduced in physical models to explore what should be the restored dimensions of the aortic root and leaflets for valve sparing to be successful. In parallel, a three-dimensional geometric model of the aortic valve was tested to evaluate its capability to predict the annulus diameter, sinotubular junction diameter, valve height, and leaflet free-edge length and height in competent spared valves.

Aortic root dilatation may alter the dimensions of the valve leaflets.

Objective: Valve-sparing surgery can be used in patients with dilated aortic roots and aortic insufficiency (AI) but has not become a common practice, in part because the spared valve may be incompetent. Our goal was to study how the dimensions of the aortic root and leaflets have changed in such patients.

Methods: Fourteen patients with dilated aortic root and AI were examined by transesophageal echocardiography.

Are there surgical implications to aortic root motion?

Background And Aim Of The Study: By increasing the longitudinal stress in the ascending aorta, downward movement of the aortic root might promote the proximal transverse tears seen in aortic dissections. The study aim was to evaluate the influence of five common cardiac conditions on the magnitude of aortic root displacement in cardiac patients.

Methods: Aortic root contrast injections were analyzed in 90 patients (mean age 68 years) to measure downward motion of the root perpendicular to the plane of the sinotubular junction (STJ).

Geometric modeling of functional trileaflet aortic valves: development and clinical applications.

The dimensions of the aortic valve components condition its ability to prevent blood from flowing back into the heart. While the theoretical parameters for best trileaflet valve performance have already been established, an effective approach to describe other less optimal, but functional models has been lacking. Our goal was to establish a method to determine by how much the dimensions of the aortic valve components can vary while still maintaining proper function.

Increased aortic wall stress in aortic insufficiency: clinical data and computer model.

Objective: The study was aimed at determining which cardiac pathologies are associated with increased longitudinal stress in the aorta and therefore may be responsible for the intimal transverse tears seen in aortic dissections.

Methods: Aortic root contrast injections were analyzed in 90 cardiac patients to measure the downward motion of the annulus during a cardiac cycle. A finite element model of the pressurized aortic root, arch and supra-aortic vessels was created to assess the influence of the aortic root motion on the aortic wall stress.

Does post-stenotic dilatation enhance collateral flow?

Our goal was to investigate whether post-stenotic dilatation (PSD) enhances collateral blood flow. In vitro experiments and computer modeling analysis were used to study the flow through stenotic segments and through collateral channels in the presence and absence of PSD. Pulsatile blood flow was provided by a left heart simulator primed with glycerol or normal saline.

Morphological changes of the aortic valve leaflets in non-compliant aortic roots: in-vivo experiments.

Background And Aim Of The Study: Age-related loss of elasticity of the naturally compliant aortic root disrupts the coordinated function of the valve leaflets. Morphological changes that developed over time in the aortic valve leaflets of non-compliant aortic roots were studied.

Methods: Stiffening of the aortic roots was achieved in vivo by applying Super Glue around the sinus of Valsalva in 27 New Zealand White rabbits.

Role of aortic root motion in the pathogenesis of aortic dissection.

Background: The downward movement of the aortic root during the cardiac cycle may be responsible for producing the circumferential tear observed in aortic dissections.

Methods And Results: Contrast injections were investigated in 40 cardiac patients, and a finite element model of the aortic root, arch, and branches of the arch was built to assess the influence of aortic root displacement and pressure on the aortic wall stress. The axial displacement of the aortic root ranged from 0 to 14 mm.

The congenitally bicuspid aortic valve: how does it function? Why does it fail?

Background: The study was intended to investigate the reason why congenitally bicuspid valves (CBAVs), which may function hemodynamically and clinically well, have a high early failure rate.

Methods: Observations were made on cryopreserved, then thawed human aortic roots containing CBAVs. Valvular function was studied in the left heart simulator using conventional and 500-frames/second cinematography, intravascular ultrasound, by preparation of silicone molds, and by computerized digital modeling.

Cause of degenerative disease of the trileaflet aortic valve: review of subject and presentation of a new theory.

Risk factors for both atherosclerotic aortic wall disease and degenerative disease of the trileaflet aortic valve are very similar if not identical. This correlation grows even stronger as the person advances in years. Because of this, it is the prevailing view that sclerosis of the trileaflet aortic valve, unless previously affected by septic or rheumatic endocarditis, is a disease similar in origin to sclerosis of the aortic wall, ie, degenerative aortic valve disease is arteriosclerosis of the aortic valve.