Timek Tomasz A, Lai David T, Tibayan Frederick, Liang David, Daughters George T, Dagum Paul, Ingels Neil B, Miller D Craig
Department of Cardiovascular Surgery and the Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, Calif, USA.
J Thorac Cardiovasc Surg. 2002 May;123(5):881-8. doi: 10.1067/mtc.2002.122296.
Ring annuloplasty prevents acute ischemic mitral regurgitation in sheep, but it also abolishes normal mitral annular and posterior leaflet dynamics. We investigated a novel surgical approach of simple septal-lateral annular cinching with sutures to treat acute ischemic mitral regurgitation.
Nine adult sheep underwent implantation of multiple radiopaque markers on the left ventricle, mitral anulus, and mitral leaflets. A septal-lateral transannular suture was anchored to the midseptal mitral anulus and externalized to a tourniquet through the midlateral mitral anulus and left ventricular wall. Open-chest animals were studied immediately postoperatively. Acute ischemic mitral regurgitation was induced by means of proximal left circumflex artery snare occlusion, and 3 progressive steps of septal-lateral annular cinching (each 2-3 mm suture tightening for 5 seconds) were performed with the transannular suture. Biplane videofluoroscopy for 3-dimensional marker coordinates and transesophageal echocardiography were performed continuously before and during left circumflex ischemia and septal-lateral annular cinching.
Acute left circumflex ischemia caused ischemic mitral regurgitation (+0.5 +/- 0.4 [baseline] vs +2.0 +/- 0.7 [ischemia]; P =.005; scale, +0-4), which decreased progressively with each step of septal-lateral annular cinching and was eliminated during the third step (ischemic mitral regurgitation, +0.6 +/- 0.5; P = not significant vs baseline). The third step of septal-lateral annular cinching decreased the septal-lateral diameter by 6.0 +/- 2.6 mm (P =.005); however, mitral anulus area reduction (8.5% +/- 1.0% and 6.9% +/- 1.9% for ischemic mitral regurgitation and septal-lateral annular cinching step 3, respectively; P =.006) and posterior leaflet excursion (50 degrees +/- 9 degrees and 44 degrees +/- 11 degrees for regurgitation and annular cinching step 3, respectively; P =.002) throughout the cardiac cycle were affected only mildly. Normal mitral annular 3-dimensional shape was maintained with septal-lateral annular cinching.
Isolated 22% +/- 10% reduction in mitral annular septal-lateral dimension abolished acute ischemic mitral regurgitation in normal sheep hearts while allowing near-normal mitral annular and posterior leaflet dynamic motion. Septal-lateral annular cinching may represent a simple method for the surgical treatment of ischemic mitral regurgitation, either as an adjunctive technique or alone, which helps preserve physiologic annular and leaflet function.
瓣环成形术可预防绵羊急性缺血性二尖瓣反流，但也会消除正常的二尖瓣环及后叶动力学。我们研究了一种用缝线进行单纯室间隔 - 侧壁瓣环缩窄的新型手术方法来治疗急性缺血性二尖瓣反流。
9只成年绵羊在左心室、二尖瓣环和二尖瓣叶上植入多个不透X线的标记物。一条室间隔 - 侧壁跨瓣缝线固定于室间隔中部的二尖瓣环，并通过二尖瓣环外侧中部和左心室壁引出至止血带。开胸动物在术后立即进行研究。通过近端左旋支动脉圈套器闭塞诱导急性缺血性二尖瓣反流，并用跨瓣缝线进行3个逐步的室间隔 - 侧壁瓣环缩窄步骤（每次缝线收紧2 - 3毫米，持续5秒）。在左旋支缺血和室间隔 - 侧壁瓣环缩窄之前及过程中持续进行双平面视频荧光透视以获取三维标记物坐标，并进行经食管超声心动图检查。
急性左旋支缺血导致缺血性二尖瓣反流（基线时为+0.5±0.4，缺血时为+2.0±0.7；P = 0.005；范围，+0 - 4），随着室间隔 - 侧壁瓣环缩窄的每个步骤逐渐减少，并在第三步时消除（缺血性二尖瓣反流，+0.6±0.5；与基线相比P无统计学意义）。室间隔 - 侧壁瓣环缩窄的第三步使室间隔 - 侧壁直径减少6.0±2.6毫米（P = 0.005）；然而，二尖瓣环面积减少（缺血性二尖瓣反流时为8.5%±1.0%，室间隔 - 侧壁瓣环缩窄第三步时为6.9%±1.9%；P = 0.006）以及整个心动周期中后叶活动度（反流时为50°±9°，瓣环缩窄第三步时为44°±11°；P = 0.002）仅受到轻微影响。室间隔 - 侧壁瓣环缩窄维持了正常的二尖瓣环三维形状。
在正常绵羊心脏中，二尖瓣环室间隔 - 侧壁尺寸单独减少22%±10%可消除急性缺血性二尖瓣反流，同时允许二尖瓣环和后叶进行接近正常的动态运动。室间隔 - 侧壁瓣环缩窄可能代表一种治疗缺血性二尖瓣反流的简单手术方法，可作为辅助技术或单独使用，有助于保留生理性瓣环和瓣叶功能。
