Trileaflet Semilunar Valve Reconstruction: Acute Porcine in Vivo Evaluation.

Objective: The surgical treatment of malformed semilunar valves in congenital heart defects is challenging in terms of providing both longevity and the potential to grow with the recipient. We investigated a new surgical technique "Trileaflet Semilunar Valve Reconstruction" in an acute porcine model, a technique with geometrical properties that could remain sufficient and allow for some growth with the child. Methods: An acute 60-kg porcine model was used. With echocardiography, baseline pulmonary valvular geometry and hemodynamics were investigated. On cardiopulmonary bypass, the pulmonary leaflets were explanted, and the Trileaflet Semilunar Valve Reconstruction was performed with customized homograft-treated pericardial neo-leaflets. Off bypass, hemodynamics was reassessed. Results: Twelve animals were investigated. The neo-valves were found sufficient in ten animals and with minimal regurgitation in two animals. The neo-valve had a peak gradient of 3 ± 2 mm Hg with a peak velocity of 0.8 ± 0.2 m/s. The coaptation in the neo-valve had a mean increase of 4 ± 3 mm, P < .001. The neo-valve had a windmill shape in the echocardiographic short-axis view, and the neo-leaflets billowed at the annular plane in the long-axis view. Conclusions: In this acute porcine model, the neo-valve had no clinically significant regurgitation or stenosis. The neo-valve had an increased coaptation, a windmill shape, and leaflets that billowed at the annular plane. These geometric findings may allow for sustained sufficiency as the annular and pulmonary artery dimension increase with the child's growth. Further long-term studies should be performed to evaluate the efficacy and the growth potential.

The matter of "unbalance" in right dominant atrioventricular septal defect.

Unbalance in atrioventricular septal defect can be found in more than one anatomic level and in different degrees at each level. The definition of "unbalance" has historically been focused in comparing the dimensions of main cardiac structures, such as the atrioventricular valve and the ventricles. However, the hemodynamic aspects of unbalance need to be considered as having, at least, similar relevance. New concepts and already described parameters must be combined and understood as a whole to help the surgical decision-making process.

Feasibility of Biventricular Repair in Right Dominant Unbalanced Atrioventricular Septal Defect: A New Echocardiographic Metric to Refine Surgical Decision-Making.

BACKGROUND: Unbalanced forms of atrioventricular septal defect continue to be challenging and present poor surgical outcomes. Echocardiographic indicators such as atrioventricular valve index, right ventricle/left ventricle inflow angle, and size of the ventricular septal defect have been identified as relevant discriminators that may guide surgical strategy. Our purpose is to describe another metric to refine surgical decision-making. METHODS: We outline a geometrical description of the anatomic features of atrioventricular septal defect and describe equations that help explain the interplay between the main echocardiographic variables. RESULTS: A new metric called "indexed ventricular septal defect" is defined as the size of the defect in relation to the valve diameter. We derive a final equation relating this index with the atrioventricular valve index and the right ventricle/left ventricle inflow angle. In the light of that equation, we discuss the interdependence of variables and employ data from a Congenital Heart Surgeons' Society study to set the limits of the new index. CONCLUSION: Combined use of indexed ventricular septal defect and atrioventricular valve index might help clarify surgical decision-making in patients with mild and moderate unbalance (modified atrioventricular valve index between 0.2 and 0.39). For indexed ventricular septal defect smaller than 0.2, biventricular repair may be recommended. Between 0.2 and 0.35, this strategy could probably be achieved depending on other factors. However, other strategies should be considered for those patients showing an indexed ventricular septal defect between 0.35 and 0.5. For values above 0.5 to 0.55, univentricular palliation might be a reasonable strategy.