Timek Tomasz A, Lai David T, Tibayan Frederick A, Daughters George T, Liang David, Dagum Paul, Ingels Neil B, Miller D Craig
Department of Cardiothoracic Surgery, Stanford University School of Medicine, CA 94305-5407, USA.
J Heart Valve Dis. 2002 Jan;11(1):2-9; discussion 10.
Septal-lateral (S-L) mitral annular diameter reduction is thought to be central to the efficacy of ring annuloplasty in correcting functional mitral regurgitation (MR), but rings perturb mitral annulus (MA) dynamic motion and limit posterior leaflet excursion. The effects of S-L annular cinching ('SLAC'), a novel method for mitral annular reduction, were investigated.
Eight adult sheep had multiple radioopaque markers placed on the left ventricle, leaflet edges, and around the MA. The S-L trans-annular suture was anchored to the mid-septal MA and externalized through the mid-lateral MA and left ventricular wall. Animals were studied immediately postoperatively with biplane videofluoroscopy before and after suture cinching to reduce annular size. MA area (MAA) and S-L dimension were calculated throughout the cardiac cycle from the annular marker coordinates. MAA contraction (AMAA) was expressed as percentage decrease from maximum to minimum MAA. Anterior (AML) and posterior (PML) leaflet angular excursion were calculated as the change in angle between each leaflet edge marker and the S-L annular dimension during the cardiac cycle. MA folding was calculated as the change in distance during systole of the mid-septal annular marker from a plane fitted to the lateral MA markers.
SLAC reduced end-diastolic (ED) S-L diameter (21.6+/-2.8 versus 17.1+/-2.6 mm; p = 0.0005) and ED MAA (618+/-126 versus 525+/-114 mm2; p = 0.0004), but did not perturb normal AMAA (15.8+/-4.1 versus 15.1+/-4.8%; p = 0.4), annular flexion (2.0+/-0.7 versus 1.8+/-0.7 mm; p = 0.3) or AML excursion (55+/-7 versus 53+/-7 degrees; p = 0.1). PML excursion was decreased only slightly (52+/-11 versus 44+/-12 degrees; p = 0.002).
SLAC substantially reduced S-L annular size, but without perturbing normal MA contraction dynamics, MA flexion, or anterior leaflet excursion. This novel surgical method might represent an alternative to mitral annuloplasty for patients with certain types of mitral pathology.
二尖瓣环隔侧-外侧（S-L）径线缩小被认为是环成形术纠正功能性二尖瓣反流（MR）疗效的关键，但人工瓣环会干扰二尖瓣环（MA）的动态运动并限制后叶活动。本研究探讨了一种新的二尖瓣环缩小方法——S-L环缩术（‘SLAC’）的效果。
对8只成年绵羊的左心室、瓣叶边缘及二尖瓣环周围放置多个不透X线的标记物。S-L跨瓣环缝线固定于二尖瓣环隔侧中点并经二尖瓣环外侧中点及左心室壁引出。术后立即通过双平面荧光透视检查在缝线收紧以缩小瓣环尺寸前后对动物进行研究。根据瓣环标记物坐标在整个心动周期计算二尖瓣环面积（MAA）和S-L径线。MAA收缩（AMAA）以MAA从最大值到最小值的百分比下降表示。前叶（AML）和后叶（PML）角位移计算为心动周期中每个瓣叶边缘标记物与S-L瓣环径线之间角度的变化。二尖瓣环折叠计算为收缩期二尖瓣环隔侧标记物与拟合二尖瓣环外侧标记物平面之间距离的变化。
SLAC使舒张末期（ED）S-L径线减小（21.6±2.8对17.1±2.6mm；p = 0.0005）以及ED MAA减小（618±126对525±114mm²；p = 0.0004），但未干扰正常的AMAA（15.8±4.1对15.1±4.8%；p = 0.4）、瓣环弯曲（2.0±0.7对1.8±0.7mm；p = 0.3）或AML位移（55±7对53±7度；p = 0.1）。PML位移仅略有减小（52±11对44±12度；p = 0.002）。
SLAC显著减小了S-L瓣环尺寸，但未干扰正常的二尖瓣环收缩动力学、二尖瓣环弯曲或前叶位移。这种新的手术方法可能为某些类型二尖瓣病变患者提供二尖瓣环成形术的替代方案。
