Publications by authors named "Pedro del Nido"

Recognition of late problems following repair of tetralogy of Fallot (TOF) with a transannular patch has stimulated modifications to preserve pulmonary valve (PV) function. This study assesses the ability of technical performance score (TPS) to determine the need for post-discharge reinterventions (RIs) in valve-sparing TOF repair. We retrospectively reviewed 157 patients following valve-sparing repair of TOF from 2007-2012.

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The network of collagen fibers in the aortic valve leaflet is believed to play an important role in the strength and durability of the valve. However, in addition to its stress-bearing role, such a fiber network has the potential to produce functionally important shape changes in the closed valve under pressure load. We measured the average pattern of the collagen network in porcine aortic valve leaflets after staining for collagen.

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Objectives: Patients with congenitally corrected transposition of the great arteries can present with tricuspid regurgitation (TR) and Ebsteinoid dysplasia of the tricuspid valve. To determine the fate of the tricuspid valve after anatomic repair and the effectiveness of tricuspid valvuloplasty, we reviewed our experience with anatomic repair of congenitally corrected transposition of the great arteries.

Methods: From 1992 to 2012, 106 patients with congenitally corrected transposition of the great arteries underwent anatomic repair.

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Objective: Recently, there has been increased interest in minimally invasive mitral valve prolapse repair techniques; however, these techniques have limitations. A new technique was developed for treating mitral valve prolapse that uses a novel leaflet plication clip to selectively plicate the prolapsed leaflet segment. The clip's efficacy was tested in an animal model.

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Objective: Early results for anatomic repair of congenitally corrected transposition of the great arteries (ccTGA) are excellent. However, the development of left ventricular dysfunction late after repair remains a concern. In this study we sought to determine factors leading to late left ventricular dysfunction and the impact of cardiac resynchronization as a primary and secondary (upgrade) mode of pacing.

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Background: Mechanisms and treatments of nonischemic functional mitral regurgitation (NIMR) are not fully established, in part, because of a lack of proper large animal models. We developed a novel technique of NIMR creation in a swine model by making multiple small incisions in the mitral annulus.

Methods And Results: Ex vivo experiments using isolated swine hearts (n=10) showed a 15% increase in annular area (6.

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Objectives: Previous work in our institution has indicated that the Technical Performance Score (TPS) is highly associated with early outcomes in select subsets of procedures and age groups. We hypothesized that the TPS could predict early outcomes in a wide range of diagnoses and age groups.

Methods: Consecutive patients discharged from January 2011 to March 2013 were prospectively evaluated.

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Background: Patients with borderline small left heart (LH) structures who initially undergo single ventricle palliation (SVP) may eventually become candidates for biventricular conversion (BC). The purpose of this study was to describe our surgical experience with BC in patients with small LH.

Methods: We reviewed our institution's records for patients who underwent BC after an initial SVP between 1995 and 2012.

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Background: Beating-heart image-guided intracardiac interventions have been evolving rapidly. To extend the domain of catheter-based and transcardiac interventions into reconstructive surgery, a new robotic tool delivery platform and a tissue approximation device have been developed. Initial results using these tools to perform patent foramen ovale closure are described.

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Background: The optimal age and duration of left ventricular (LV) training in congenitally corrected transposition (ccTGA) with an unprepared LV is unknown. The objective of this study was to review the effect of age at pulmonary artery banding (PAB) and duration of ventricular training on LV function and aortic regurgitation (AR) after anatomic repair.

Methods: The medical records of all patients who underwent PA banding for LV training between 1998 and 2011 were retrospectively reviewed.

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Surgical repair of the aortic valve with the use of leaflet grafts made from pericardium has been shown to be a viable option, particularly in children, in whom valve replacement has strong disadvantages. We present guidelines for sizing treated autologous pericardium to fabricate a leaflet graft for single-leaflet replacement. Both our clinical experience and experimental evidence indicate that effective repairs are best achieved by use of a semicircular graft with a diameter 10% to 15% greater than the sinotubular junction diameter in diastole.

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Objective: Congenital heart valve disease is one of the most common abnormalities in children. There are limited technological solutions available for treating children with congenital heart valve diseases. The aim of this study is to provide the details of the consensus reached in terms of pediatric definitions, design approach, in vitro testing, and clinical trials, which may be used as guidance for developing prosthetic heart valves for the pediatric indication.

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Background: We have shown previously that technical performance score (TPS) is strongly associated with early mortality and major postoperative adverse events in a diverse group of patients. We now report evaluation of the validity of TPS in predicting late outcomes in the same group of patients.

Methods: Patients who underwent surgery between June 1, 2005 and June 30, 2006 were included.

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Achieving superior outcomes through the use of robots in medical applications requires an integrated approach to the design of the robot, tooling and the procedure itself. In this paper, this approach is applied to develop a robotic technique for closing abnormal communication between the atria of the heart. The goal is to achieve the efficacy of surgical closure as performed on a stopped, open heart with the reduced risk and trauma of a beating-heart catheter-based procedure.

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Mitral valve repair is a complex procedure that requires the ability to predict closed valve shape through the examination of an unpressurized, accid valve. These procedures typically include the remodeling of the mitral annulus through the insertion of an annuloplasty ring. While simulations could facilitate the planning of the procedure, traditional finite-element models of mitral annuloplasty are too slow to be clinically feasible and have never been validated in tissue.

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Patients with repaired tetralogy of Fallot account for the majority of cases with late onset right ventricle (RV) failure. A new surgical procedure placing an elastic band in the right ventricle is proposed to improve RV function measured by ejection fraction. A multiphysics modeling approach is developed to combine cardiac magnetic resonance imaging, modeling, tissue engineering and mechanical testing to demonstrate feasibility of the new surgical procedure.

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Objectives: Truncal valve regurgitation remains a short- and long-term risk factor for patients with truncus arteriosus. There are limited data available on techniques and outcomes of truncal valve repair (TVR). The aim of this study was to report our experience with TVR in patients of all ages.

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Background: Management of unbalanced common atrioventricular canal (UCAVC) defect by a single-ventricle (SV) approach frequently results in poor outcomes, especially in trisomy 21 patients. In this report we describe our results with conversion to biventricular circulation in UCAVC patients with SV palliation.

Methods: Retrospective review of patients with UCAVC undergoing biventricular conversion from prior SV palliation between 2003 and 2011 was conducted.

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Although hypoplasia of left heart structures presents with a spectrum of severity, management decisions are typically dichotomous: single-ventricle palliation or biventricular repair. Since the long-term outcomes of single-ventricle palliation are sub-optimal, strategies to aggressively pursue biventricular circulation in patients with borderline left heart structures have been developed. Recent strategies and surgical techniques to rehabilitate the left heart in patients with borderline left heart are described.

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Background: Mitral valve replacement remains the last resort for treatment of congenital mitral valve disease. Enlarging the mitral annulus at the time of mitral valve replacement may allow implantation of a larger prosthesis in children.

Methods: All mitral valve replacement procedures from 1990 to 2012 were included, and mitral annulus enlargement techniques were analyzed.

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Objectives: A previously published randomized clinical trial comparing cardiac magnetic resonance (CMR) versus routine catheterization in patients with functional single ventricle before bidirectional Glenn (BDG) operation demonstrated similar short-term post-BDG outcomes. We sought to assess late outcomes in this cohort to ascertain any long-term effects of this evaluation strategy.

Methods: Retrospective review of enrolled patients through most recent follow-up was performed on all 82 patients in the original cohort, at a median age of 8.

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The hemodynamics in patients with total cavopulmonary connections (TCPC) is generally very complex and characterized by patient-to-patient variability. To better understand its effect on patients' outcome, CFD models are widely used, also to test and optimize surgical options before their implementation. These models often assume rigid geometries, despite the motion experienced by thoracic vessels that could influence the hemodynamics predictions.

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Right ventricular (RV) and left ventricular (LV) myocardium differ in their pathophysiological response to pressure-overload hypertrophy. In this report we use microarray and proteomic analyses to identify pathways modulated by LV-aortic banding (AOB) and RV-pulmonary artery banding (PAB) in the immature heart. Newborn New Zealand White rabbits underwent banding of the descending thoracic aorta [LV-AOB; n = 6].

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