Skov Søren N, Røpcke Diana M, Tjørnild Marcell J, Ilkjær Christine, Rasmussen Jonas, Nygaard Hans, M Hasenkam J, Jensen Morten O, Nielsen Sten L
Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.
Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark. Electrnic correspondence:
J Heart Valve Dis. 2017 May;26(3):295-303.
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.
All measurements were performed in vivo using a porcine model. A total of 28 pigs (bodyweight ca. 80 kg) were randomized to four groups: (i) with no ring; (ii) with a novel remodeling ring; (iii) with a semi-rigid ring (Physio I Ring, Edwards Lifesciences); and (iv) with a rigid ring (Classic Annuloplasty Ring, Edwards Lifesciences). Force measurements were performed using a dedicated transducer to determine remodeling capacity of the annuloplasty rings. Geometric parameters were measured by implanting sonomicrometry crystals along the mitral annulus.
All ring groups significantly restricted the cyclic change of the mitral annulus compared with the 'no-ring' group. The change and maximum value of the annular height were maintained for the novel ring but were significantly decreased for the rigid and semi-rigid rings compared with the 'no-ring' group. Mitral annular force measurements confirmed that the overall remodeling capacity of the novel ring was comparable with the conventional ring groups, and significantly higher in the septal-lateral direction compared to the semi-rigid ring.
In-vivo geometry and force measurements indicated that the intended design features of the new device were successfully provided. The novel ring concept with remodeling properties, combined with the advantages of a flexible annuloplasty ring, is unique. The maintenance of annular saddle shape and cyclic change in annular height may be an important step towards improved mitral valve repair.
天然瓣环的形态在舒张期近乎扁平，而在收缩期变为鞍形。本研究旨在测试一种新型的具有内置间隔 - 侧壁固定和瓣环连合处轴向灵活性的重塑瓣环成形环，以维持瓣环鞍形的变化。研究目的是评估这种新型瓣环成形环与天然瓣膜以及半刚性和刚性瓣环成形环相比的体内生物力学性能。
所有测量均在猪模型体内进行。总共28头猪（体重约80千克）被随机分为四组：（i）不植入环；（ii）植入新型重塑环；（iii）植入半刚性环（Physio I Ring，爱德华生命科学公司）；（iv）植入刚性环（Classic Annuloplasty Ring，爱德华生命科学公司）。使用专用传感器进行力测量，以确定瓣环成形环的重塑能力。通过沿二尖瓣环植入超声测微晶体来测量几何参数。
与“无环”组相比，所有环组均显著限制了二尖瓣环的周期性变化。新型环能维持瓣环高度的变化和最大值，但与“无环”组相比，刚性和半刚性环的瓣环高度变化和最大值显著降低。二尖瓣环力测量证实，新型环的整体重塑能力与传统环组相当，且在间隔 - 侧壁方向上比半刚性环显著更高。
体内几何形状和力测量表明，新装置成功具备了预期的设计特征。具有重塑特性的新型环概念，结合了柔性瓣环成形环的优点，是独一无二的。维持瓣环鞍形和瓣环高度的周期性变化可能是改善二尖瓣修复的重要一步。
