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.

A handsewn pericardial valved pulmonary conduit: pulsatile flow loop in vitro and acute porcine in vivo evaluation.

OBJECTIVES: Right ventricle to pulmonary artery anatomic discontinuity is common in complex congenital heart malformations. Handsewn conduits are a practised method of repair. In a proof-of-concept study, we evaluated pulmonary valve replacement with a handsewn pericardial valved pulmonary conduit in vitro and in vivo. METHODS: A pulsatile flow-loop model (in vitro) and an acute 60-kg porcine model (in vivo) were used. With echocardiography and pressure catheters, baseline geometry and fluid dynamics were measured. The pulmonary valve was replaced with a handsewn glutaraldehyde-treated pericardial valved pulmonary conduit corresponding to a 21-mm prosthetic valve, after which geometric measurements and fluid dynamics were reassessed. RESULTS: In vitro, 15 pulmonary trunks at 4 l/min and 13 trunks at 7 l/min, and in vivo, 11 animals were investigated. The valved pulmonary conduit was straightforward to produce at the operating table and easy to suture in place. All valves were clinically sufficient in vitro and in vivo. The mean transvalvular pressure gradient in the native valve and the conduit was 8 mmHg [standard deviation (SD): 2] and 7 mmHg (SD: 2) at 4 l/min in vitro, 19 mmHg (SD: 3) and 17 mmHg (SD: 4) at 7 l/min in vitro and 3 mmHg (SD: 2) and 6 mmHg (SD: 3) in vivo. CONCLUSIONS: Our proof-of-concept demonstrates no early evidence of structural damage to the conduit, and the fluid dynamic data were acceptable. The handsewn conduit can be produced at the operating table.