A Novel Aortic Regurgitation Model from Cusp Prolapse with Hemodynamic Validation Using an Ex Vivo Left Heart Simulator

Biomechanical engineering comparison of four leaflet repair techniques for mitral regurgitation using a novel 3-dimensional–printed left heart simulator

“…A 3-dimensional (3D)-printed customized and modular left heart simulator, which we have previously described extensively, was used as our testing platform to compare various mitral valve repair techniques ( Figure 1 , A ). 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 Briefly, a 3D printer (M2, Carbon 3D, Redwood City, Calif) was used to rapidly prototype a modular left heart which was mounted to a pulsatile linear actuator (Vivitro Superpump, Vivitro Labs, Victoria, BC, Canada). The device was equipped with pressure and flow sensors to record atrial, ventricular, and aortic pressures as well as transmitral and transaortic flow probes The chamber itself is mostly rigid, with the exception of elastomeric seals and the elastomeric annular mount.…”

Heart Valve Biomechanics: The Frontiers of Modeling Modalities and the Expansive Capabilities of Ex Vivo Heart Simulation

“…From these studies, it was concluded that straight grafts were associated with lower regurgitant fractions and more favorable leaflet mechanics, specifically lower cusp opening and closing velocities and relative forces (p ≤ 0.01 for each), most closely recapitulating native aortic root biomechanics. Additionally, work on novel AR models has led to detailed understandings behind disease mechanisms, such as cusp prolapse, bicuspid AV, and root aneurysm, and repairs, such as free margin suspension, free margin plication, and VSARR, which will lead to important insights on optimal repair strategies for AR (93)(94)(95). In these studies, while a wide variety of hemodynamic parameters were measured and extracted from pressure and flow data, regurgitation was specifically derived from flow measurements through the AV by integrating flow through the aorta during diastole.…”

Cusp repair techniques in bicuspid and tricuspid aortic valves

“…In fact, commissure malalignment in height or orientation has been biomechanically shown to critically contribute to cusp prolapse in both bicuspid and tricuspid aortic valve regurgitation. 3 , 17 VSRR is a highly versatile technique and has been adopted to address a wide variety of aortic and even pulmonary autograft valve dysfunctions. 7 , 23 , 24 , 25 Although VSRR repair has undergone several iterations, the detailed repair techniques remain largely similar.…”

“… 1 The pathophysiology of AR is dependent on the acuity of the disease and the dysfunction of the aortic valvular apparatus. 2 Functionally, AR can be classified into type I, with normal cusp motion but dilated functional aortic annulus (FAA) or cusp perforation; type II, with cusp prolapse due to excess cusp tissue or commissural disruption 3 ; or type III, with cusp restriction typically seen in bicuspid aortic valve (BAV), degenerative, or rheumatic valvular disease. 2 This functional AR classification allows a systematic approach to the surgical treatment options for AR.…”