Entire Mitral Valve Reconstruction Using Porcine Extracellular Matrix: Adding a Ring Annuloplasty.

Purpose: This study investigated the implications of inserting a flexible annuloplasty ring after reconstructing the entire mitral valve in a porcine model using a previously investigated tube graft design made of 2-ply small intestinal submucosa extracellular matrix (CorMatrix®).

Methods: An acute model with eight 80-kg pigs, each acting as its own control, was used. The entire mitral valve was reconstructed with a 2-ply small intestinal submucosa extracellular matrix tube graft (CorMatrix®).

Reverse remodeling of tricuspid valve morphology and function in chronic thromboembolic pulmonary hypertension patients following pulmonary thromboendarterectomy: a cardiac magnetic resonance imaging and invasive hemodynamic study.

Background: To investigate changes in tricuspid annulus (TA) and tricuspid valve (TV) morphology among chronic thromboembolic pulmonary hypertension (CTEPH) patients before and 12 months after pulmonary thromboendarterectomy (PEA) and compare these findings to normal control subjects.

Methods: 20 CTEPH patients and 20 controls were enrolled in the study. The patients were examined with echocardiography, right heart catherization and cardiac magnetic resonance imaging prior to PEA and 12 months after.

Annular and subvalvular dynamics after extracellular matrix mitral tube graft implantation in pigs.

Objectives: Entire mitral valve reconstruction with an extracellular matrix tube graft is a potential candidate to overcome the current limitations of mechanical and bioprosthetic valves. However, clinical data have raised concern with respect to patch failure. The aim of our study was to evaluate the impact of extracellular matrix mitral tube graft implantation on mitral annular and subvalvular regional dynamics in pigs.

Annular Dynamics and Leaflet Geometry in Patch Reconstruction of the Posterior Mitral Leaflet After Adding a Flexible Annuloplasty Ring.

Purpose: Patch reconstruction of the posterior mitral leaflet using small intestinal submucosa extracellular matrix has been successfully performed in a porcine study. The patch reconstruction, however, resulted in non-physiological systolic widening of the mitral annulus, suggesting the need for an annuloplasty ring. The objective was to characterize the impact on annular dynamics and leaflet geometry of adding a flexible annuloplasty ring to the posterior mitral leaflet patch reconstruction.

Mitral Valve Posterior Leaflet Reconstruction Using Extracellular Matrix: In Vitro Evaluation.

Purpose: To investigate the anatomical and functional effects of complete surgical reconstruction of the posterior mitral leaflet and associated chordae tendineae with a patch made of 2-ply small intestinal submucosal extracellular matrix in vitro.

Methods: Seven explanted mitral valves with intact subvalvular apparatus from 80-kg pigs were evaluated in a left heart simulator and served as their own controls. After testing the native valve, the mitral posterior leaflet and associated chordae tendineae were excised and reconstructed by using the 2-ply small intestinal submucosa extracellular matrix patch.

Long-term changes of exercise hemodynamics and physical capacity in chronic thromboembolic pulmonary hypertension after pulmonary thromboendarterectomy.

Background: A substantial number of chronic thromboembolic pulmonary hypertension (CTEPH) patients experience dyspnea on exertion and limited exercise capacity despite surgically successful pulmonary endarterectomy (PEA). We sought to prospectively evaluate resting and peak exercise hemodynamics before, 3 and 12 months after PEA in consecutive CTEPH-patients and correlate it to physical functional capacity.

Methods And Results: Twenty consecutive CTEPH-patients were examined.

Altered stresses and dynamics after single and double annuloplasty ring for aortic valve repair.

Objectives: Aortic valve repair procedures for the treatment of isolated aortic valve insufficiency may be improved by stabilizing the functional aortic annulus using a double annuloplasty ring at the aortic annulus and sinotubular junction (STJ). The objective of this study was to compare the geometrical changes and aortic root stress distribution when using a single subvalvular ring and a double sub- and supravalvular ring in vivo.

Methods: Both the single- and double-ring procedures were performed successively in nine 80-kg pigs.

Long-term changes of right ventricular myocardial deformation and remodeling studied by cardiac magnetic resonance imaging in patients with chronic thromboembolic pulmonary hypertension following pulmonary thromboendarterectomy.

Background: Right ventricular (RV) afterload in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is associated with reduced myocardial contractility and ventriculoarterial coupling. The impact of increased afterload on RV myocardial deformation was assessed by comparing the characteristics of CTEPH patients to healthy controls at baseline, and by comparing characteristics of CTEPH patients before and 12 months after pulmonary endarterectomy (PEA).

Methods: Cardiac deformation and function of CTEPH patients (n = 20) and healthy controls (n = 20) were assessed by cardiac magnetic resonance (CMR).

Entire mitral reconstruction with porcine extracellular matrix in an acute porcine model.

Objective: The objective of our study was to investigate the feasibility of reconstructing the entire mitral valvular and subvalvular apparatus in pigs using a modified tube graft design made of 2-ply small intestinal submucosa extracellular matrix.

Methods: The reconstructions were performed in an acute 80-kg porcine model with 8 pigs, each acting as its own control. A modified tube graft was designed from a sheet of 2-ply small intestinal submucosa extracellular matrix.

Long-term changes of resting and exercise right ventricular systolic performance in patients with chronic thromboembolic pulmonary hypertension following pulmonary thromboendarterectomy - A two-dimensional and three-dimensional echocardiographic study.

Aims: To characterize right ventricular (RV) geometry and function in chronic thromboembolic pulmonary hypertension (CTEPH) patients at rest and during exercise before pulmonary thromboendarterectomy (PEA), and at 3 and 12 months after PEA using two-dimensional and three-dimensional echocardiography with reference to clinical performance and exercise capacity.

Methods And Results: Forty subjects (20 CTEPH patients and 20 controls) were enrolled between December 2014 and January 2017. Three-dimensional echocardiography demonstrated a significant reduction and normalization of end-diastolic and end-systolic RV volumes in CTEPH patients 12 months after PEA.

Comparison of Dacron ring and suture annuloplasty for aortic valve repair-a porcine study.

Background: A subvalvular annuloplasty is often used for aortic valve repair in patients with isolated aortic regurgitation with aortic annulus dilatation. Our aim was to characterize and compare annulus geometry and dynamics of the Dacron ring and suture annuloplasty and compare it with the native aortic annulus under standardized conditions.

Methods: We randomized 29 pigs of 80 kg into a Dacron ring group, a suture annuloplasty group and a native control group.

Asymmetric Dynamics of the Native Aortic Annulus Evaluated by Force Transducer and Sonomicrometry in a Porcine Model.

Purpose: With new repair techniques of the aortic root and valve emerging, a detailed understanding of the dynamics of the aortic annulus and valve is required for optimal results. The objective of this study was to characterize geometrical changes and force distribution of the native porcine aortic annulus throughout the cardiac cycle.

Methods: Measurements were performed in an acute 80 kg porcine model (n = 7) using sonomicrometry crystals in the aortic annulus for evaluation of geometry and dynamics, annular force transducer evaluating force distribution, and pressure measurements and echocardiography evaluating valve performance.

Entire mitral valve reconstruction using porcine extracellular matrix: static in vitro evaluation.

Objectives: To investigate the feasibility of reconstruction of the entire mitral valve using a tube graft made of 2-ply small intestinal submucosa extracellular matrix in vitro.

Methods: Seven explanted mitral valves with intact subvalvular apparatus from 80 kg pigs were evaluated in a left heart simulator and served as controls. After testing the native valve, the leaflets and chordae tendineae were explanted, and the 2-ply small intestinal submucosa extracellular matrix (CorMatrix®; Cardiovascular Inc.

New Mitral Valve Annuloplasty Concept: Optimizing Annular Dynamics and Force Distribution.

Background: Temporal three-dimensional (3D) analysis of the mitral valve biomechanics has prompted a re-evaluation of surgical approaches and repair device designs to accommodate the natural dynamics of the valve. Such new designs strive to obtain lower annulus restraining forces, resulting in more natural leaflet and chordal stresses. A new annuloplasty system was evaluated using 3D motion and out-of-plane force analysis.

Mitral annuloplasty ring with selective flexibility for septal-lateral contraction and remodelling properties.

Objectives: To develop and evaluate a novel mitral annuloplasty ring with selective flexibility for septal-lateral contraction and rigidity for septal-lateral dilatation in an acute porcine model.

Methods: The novel mitral annuloplasty ring was designed with slits in the luminal posterior segment and annular lateral segments. The slits were designed to allow inward motion during contraction and to block outward motion during dilation.

Biomechanical characterization and comparison of different aortic root surgical techniques.

Objectives: Understanding the biomechanical impact of aortic valve-sparing techniques is important in an era in which surgical techniques are developing and are increasingly being used based on biomechanical understanding that is essential in the refining of existing techniques. The objective of this study was to describe how the valve-sparing remodelling (Yacoub) and reimplantation (David Type-1) techniques affect the biomechanics of the native aortic root in terms of force distribution and geometrical changes.

Methods: Two force transducers were implanted into 22 pigs, randomized to 1 of 3 groups (David = 7, native = 7 and Yacoub = 8) along with 11 sonomicrometry crystals and 2 pressure catheters.

Mitral valve posterior leaflet reconstruction using extracellular matrix: an acute porcine study.

Objectives: To investigate mitral valve posterior leaflet and subvalvular reconstruction using a 2-ply small intestinal submucosal extracellular matrix sheet.

Methods: Mitral valve posterior leaflet and subvalvular reconstruction was characterized in an acute 80-kg porcine model with 7 pigs acting as their own controls. The characterization was based on pressure catheter measurements of pressure differences to identify mitral regurgitation, stenosis and systolic anterior motion.

Mid-term function and remodeling potential of tissue engineered tricuspid valve: Histology and biomechanics.

Objective: Tricuspid valve reconstruction using a small intestinal submucosal porcine extracellular matrix (ECM) tube graft is hypothesized to be durable for six months and show signs of recellularization and growth potential. The purpose was to histologically and biomechanically test ECM valves before and after six months of implantation in pigs for comparison with native valves.

Methods: Ten 60 kg pigs were included, which survived tricuspid valve tube graft insertion.

Remodeling Mitral Annuloplasty Ring Concept with Preserved Dynamics of Annular Height.

Background And Aim Of The Study: The configuration of the native annulus changes from nearly flat in the diastolic phase to saddle-shaped in the systolic phase. The present study was conducted to test a novel remodeling annuloplasty ring with built-in septal-lateral fixation and commissural axial flexibility so as to maintain the change in annular saddle shape. The study aim was to evaluate the in-vivo biomechanical performance of the novel annuloplasty ring, compared with the native valve and a semi-rigid and rigid annuloplasty ring.

The effect of different mitral annuloplasty rings on valve geometry and annular stress distribution†.

Objectives: To characterize the remodelling effects and deformational forces of normosized rigid, semirigid and flexible mitral annuloplasty rings after implantation in healthy pigs.

Methods: Measurements were performed in vivo with 80-kg porcine animals. Twenty-eight animals were randomized into a no ring group, a flexible ring group (Duran AnCore Ring, Medtronic, Minneapolis, MN, USA), a rigid ring group (Carpentier-Edwards Classic annuloplasty ring, Edwards Lifesciences, Irvine, CA, USA) and a semirigid ring group (Carpentier-Edwards Physio I annuloplasty ring, Edwards Lifesciences).

Small intestinal submucosa tricuspid valve tube graft shows growth potential, remodelling and physiological valve function in a porcine model†.

Objectives: Tricuspid valve reconstruction using small intestinal submucosal extracellular matrix (ECM) designed as a tube graft is possible in severe valve pathology. Using cardiac magnetic resonance imaging (MRI) and digital photograph imaging, valves were evaluated after 6 months in a porcine model.

Methods: Ten 60 kg pigs received a tricuspid valve tube graft.

Regional Changes in Leaflet Coaptation Dynamics After Total Tricuspid Reconstruction.

Background: Stentless porcine extracellular matrix tricuspid tube grafts were developed for tricuspid valve reconstruction. The purpose of this study was to conduct an echocardiographic assessment of the performance of native and tube graft leaflets in an acute porcine model.

Methods: Fourteen 65-kg pigs were randomly assigned to tube graft (n = 7) or control with native valve preservation (n = 7).

Semi-rigid mitral annuloplasty rings improve myocardial stress adaptation compared to rigid rings: insights from in vitro and in vivo experimental evaluation.

Objectives: Investigate myocardial stress adaptation and remodelling capacity of a rigid and semi-rigid mitral annuloplasty ring.

Methods: The annuloplasty rings were characterized in vitro in a mechanical setup with tensile and compressive forces from 0 to 3 N. The rings were tested with and without fixation of the ring to imitate the effect of annular implantation.

Current status of transcatheter mitral valve repair therapies - From surgical concepts towards future directions.

Transcatheter mitral valve (MV) intervention has emerged as an effective treatment option for symptomatic severe mitral regurgitation (MR) in patients considered to be inoperable or at high operative risk for surgical MV surgery. In primary mitral regurgitation, surgical repair is the standard of care. Transcatheter edge-to-edge MV repair with the MitraClip system has the largest clinical experience to date and offers a sustained clinical benefit in selected surgical high-risk patients.