A Sutureless Vascular Closure Device for Emergent Bovine Xenograft Implantation.

A novel vascular staple (C-staple) was developed that does not enter the vasculature lumen during anastomoses. The objective of this study was to demonstrate C-staple safety when used with a bovine xenograft and compare efficacy of the C-staple procedure with Anastoclip surgical clips or suturing when used with a bovine xenograft. Eight sheep had an acute comparison between suturing and C-staples using both common carotid arteries.

Evaluation of a Bovine Vascular Graft in Sheep.

The study objective was to determine safety and efficacy of a treated bovine vascular xenograft, in two Good Laboratory Practice compliant studies in sheep following carotid graft implantation. In one study, a 3- to 5-mm diameter xenograft was implanted into the right carotid artery of male sheep and compared to autologous jugular vein and a polymeric grafts similarly implanted. In a second study, a 9.

Community-based walking exercise for peripheral artery disease: An exploratory pilot study.

Supervised walking exercise is an effective treatment to improve walking ability of patients with peripheral artery disease (PAD), but few exercise programs in community settings have been effective. The aim of this study was to determine the efficacy of a community-based walking exercise program with training, monitoring and coaching (TMC) components to improve exercise performance and patient-reported outcomes in PAD patients. This was a randomized, controlled trial including PAD patients (n=25) who previously received peripheral endovascular therapy or presented with stable claudication.

In vitro study of percutaneous aortic valve replacement: selection of a tissue valve.

Background: Selection of the best tissue valve is an essential step before percutaneous aortic valve replacement (PAVR) becomes a clinical reality. The aim of this study was to evaluate in vitro three different tissue valves mounted within the same endovascular stent.

Methods: Thirty stented valves (10 aortic porcine, 10 pulmonary porcine, and 10 pericardial tubular) were sutured within a 32-mm long by 23-mm diameter cobalt-nickel stent.

Further information from a sonometric study of the normal tricuspid valve annulus in sheep: geometric changes during the cardiac cycle.

Background And Aim Of The Study: In a previous sono-metric study, changes were described that occurred in the normal tricuspid valve during the cardiac cycle. However, the wealth of data available suggested the need for reporting further findings that should contribute to a better understanding of the dynamics of the tricuspid valve.

Methods: Thirteen sonomicrometry transducers were placed in the hearts of each of seven sheep.

Mitral valve basal chordae: comparative anatomy and terminology.

Background: Recent awareness of the importance of the mitral valve's basal chordae stimulated a comparative anatomic study of these chordae in 11 human, 10 ovine, and 10 porcine hearts.

Methods: The basal chordae were defined as the chordae that arise from the papillary muscles and insert into the ventricular aspect of the leaflets.

Results: All leaflet insertions of the basal chordae were close to the annulus, except at the anterior mitral leaflet, where insertion was at the junction of the smooth and rough zones.

Dimensional ratios of normal mitral valve structures: a tool for determining the degree of geometric distortion in individual patients.

Background And Aim Of The Study: One objective of mitral valve repair is to restore the distorted mitral apparatus geometry to its normal dimensions specific for each patient. Because all dimensions of the normal aortic and mitral valves should be related, it was hypothesized that, in the presence of a normal aortic annulus, it would be possible to determine the dimensions of the structures needed for mitral valve repair.

Methods: In seven sheep, sonometric ultrasound crystals were implanted at the left and right trigones (T1, T2), lateral annulus (P1, P2), and the tips of the anterior and posterior papillary muscles (Ml, M2).

Coronary flow obstruction in percutaneous aortic valve replacement. An in vitro study.

Objective: Coronary flow obstruction is a serious complication reported in percutaneous aortic valve replacement. In an in vitro study of porcine hearts, the effects of valved stent implantation on coronary artery flow were studied with the native valve's leaflets intact and excised.

Methods: The right and left main coronary arteries of porcine hearts were dissected 20mm distal to the aortic root and directed into lengths of latex tubing leading to collection flasks.

The papillary muscles as shock absorbers of the mitral valve complex. An experimental study.

Objective: Although it is known that the papillary muscles ensure the continuity between the left ventricle (LV) and the mitral apparatus, their precise mechanism needs further study. We hypothesize that the papillary muscles function as shock absorbers to maintain a constant distance between their tips and the mitral annulus during the entire cardiac cycle.

Materials And Methods: Sonomicrometry crystals were implanted in five sheep in the mitral annulus at the trigones (T1 and T2), mid anterior annulus (AA) mid posterior annulus (PA), base of the posterior lateral scallops (P1 and P2), tips of papillary muscles (M1 and M2), and LV apex.

Sutureless stented aortic valve implantation under direct vision: lessons from a negative experience in sheep.

Background And Aim Of The Study: Percutaneous aortic valve replacement has been proposed as a valid alternative to surgery in selected cases; however, it still has many problems. As a less radical preliminary step, we implanted a balloon-expandable stented aortic valve under direct vision in sheep.

Methods: Under cardiopulmonary bypass (CPB) and through a transverse aortotomy, an aortic valve mounted in a long tubular balloon-expandable stent was implanted in six acute sheep.

Functional terminology for the tricuspid valve.

Background And Aim Of The Study: Advances in echocardiography have awoken new interest in the tricuspid valve, which otherwise has been largely ignored by cardiologists and surgeons. These advances demand a precise terminology for the description of the tricuspid valve's different anatomic structures in health and disease. While simple nomenclatures have been developed for the mitral valve, no such system has been described for the tricuspid valve.

Progression of tricuspid regurgitation after repaired functional ischemic mitral regurgitation.

Background: Despite correction of left-sided cardiac lesions, associated functional tricuspid regurgitation (TR) that was surgically ignored can persist. It can also appear de novo. The aim of this study was to analyze TR in a group of patients who underwent successful revascularization and mitral valve repair (MVRep) for functional ischemic mitral regurgitation (MR).

Aortic root dynamics are asymmetric.

Background And Aim Of The Study: The presence of conformational changes in the aortic root during the cardiac cycle is well known, but precise information on time-related changes at each level of the root is lacking.

Methods: High-resolution, 3D sonomicrometry (200 Hz) was applied in an acute sheep model. Twelve crystals were implanted in eight sheep at each base (n = 3), commissure (n = 3), sinotubular junction (n = 3) and ascending aorta (n = 3).

Anterior mitral basal 'stay' chords are essential for left ventricular geometry and function.

Background And Aim Of The Study: Among the anterior mitral basal chords, two particularly strong and thick stay chords (SC) remain under tension during the entire cardiac cycle. Collagen fibers of the anterior mitral leaflet (AML) are oriented from insertion of the SC on the AML to the fibrous trigones (FT), suggesting that local stress is directed from the papillary muscles (PM) over the SC and AML to the FT, maintaining left ventricular (LV) geometry.

Methods: Sonomicrometry crystals were implanted in sheep at the LV apex (A), the anterior (AW) and septal (SW) LV wall, the PM tips (M1 and M2), the SC insertion into the AML (S1 and S2), the posterior (PMA) and lateral (P1 and P2) mitral annulus, the FT (T1 and T2), the tips of the anterior (AL) and posterior (PL) mitral leaflets, and the base of the aortic right coronary sinus (RCS).

Improving the results of small-bore vascular graft testing in rabbits: a technical primer.

Appropriate models to evaluate the in vivo behavior of small-diameter grafts are varied. To evaluate the behavior of small-diameter, bovine-derived grafts in the arterial circulation, we chose the rabbit abdominal aorta model. In the development of our procedure, we evaluated several models published in the literature, with unsatisfactory results.

Anterior mitral leaflet mobility is limited by the basal stay chords.

Background: We hypothesize that 2 tendon-like anterior basal stay chords, which remain taut during the entire cardiac cycle, limit the motion of the anterior mitral leaflet.

Methods And Results: Sonomicrometric crystals were implanted in 6 sheep at the insertion of stay chords at anterior mitral leaflet (S1 and S2), papillary muscle tips, fibrous trigones, mitral annulus, and the tip of the anterior leaflet (AL). Distances between crystals were recorded before and after section of stay chords.

Cellular expression of PCNA and procollagen in vital and ethanol-treated autologous pericardial implants in sheep.

Background And Aims Of The Study: Cardiovascular surgeries involving repair or reconstruction of heart valve leaflets with vital autologous pericardium have shown detrimental healing outcomes, mainly fibrosis with retraction. It is proposed that cells intrinsic to the pericardial implants may contribute to this fibrosis by becoming activated to proliferate and synthesize type I collagen.

Methods: Vital and ethanol-treated autologous pericardium were implanted as rectangular flaps bisecting the lumen in the descending aorta of sheep to simulate a heart valve leaflet.

An in vitro model of pericardial tissue healing.

Introduction: A previous study in our laboratory showed that a flap of fresh autologous pericardium bisecting the aorta of sheep retracted and became fibrotic. Histologic analyses suggested that activated cells within the pericardium contributed to the retraction of the implant. Here we report the development of an in vitro model to investigate the effects of serum on cellular proliferation and cell-mediated tissue contraction.

A temporarily stented, autologous pericardial aortic valve prosthesis.

Background And Aim Of The Study: A new bioprosthesis has been developed that is: (i) constructed from glutaraldehyde-treated autologous pericardium due to its lack of antigenicity and low cost; (ii) easily constructed in the operating room; (iii) stentless but easy to implant by using a temporary stent that is removed once its function is no longer necessary; and (iv) implanted with a single proximal suture and three commissural stitches.

Methods: This prosthesis was implanted in the subcoronary aortic position of six sheep. The mean prosthesis size was 19.

Aortic and pulmonary root: are their dynamics similar?

Objectives: The long-term behavior of the pulmonary autograft in the aortic position (Ross procedure) remains uncertain. Using three-dimensional (3D) sonomicrometry (200 Hz) we compared the dynamics of the aortic and pulmonary roots.

Methods: Twenty-four crystals were implanted in each aortic (eight sheep) and pulmonary roots (six sheep) at: base (3 x 2), commissures (3 x 2), sinotubular junction (3 x 2), ascending aorta (3) and pulmonary trunk (3).

A new method for the preservation of aortic valve homografts.

Background And Aim Of The Study: Aortic valve homografts were treated with 50% ethanol and glycerol followed by freeze-drying (D-Hydro). Comparative results of fresh versus D-Hydro-treated aortic roots implanted for up to nine months in the descending aorta of sheep with induced aortic regurgitation (AR) are reported.

Methods: Six fresh and six D-Hydro valves were implanted in 12 sheep for three, six and nine months, and echocardiography and pressures were taken at surgery and sacrifice.

Hemodynamic evaluation of a new stentless autologous pericardial mitral valve.

Background: There is no satisfactory mitral valve prosthesis. An ideal mitral valve substitute should be biologic, nonantigenic, and anatomically correct.

Methods: We developed a stentless, chordal-supported (including anterior basal stay chords) mitral valve made with glutaraldehyde-treated autologous pericardium.

Surgical techniques for the repair of anterior mitral leaflet prolapse.

Myxomatous disease is the leading cause of mitral valve regurgitation in the developed world. Although posterior mitral leaflet (PML) prolapse is the most common cause of regurgitation and of repair, lesions of the anterior mitral leaflet (AML) are often considered beyond the possibilities of repair. The surgical anatomy and pathology of the AML and a precise terminology for the location of the lesions are described.