Langer Frank, Rodriguez Filiberto, Cheng Allen, Ortiz Saskia, Nguyen Tom C, Zasio Mary K, Liang David, Daughters George T, Ingels Neil B, Miller D Craig
Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, Calif 94305-5247, USA.
J Thorac Cardiovasc Surg. 2006 Apr;131(4):868-77. doi: 10.1016/j.jtcvs.2005.11.027. Epub 2006 Mar 2.
Residual or recurrent mitral regurgitation frequently occurs after mitral valve repair for ischemic mitral regurgitation with an annuloplasty ring. Because annuloplasty primarily addresses annular dilatation, we studied an adjunctive technique that might correct restricted leaflet (Carpentier type IIIb) systolic closing motion, which often accompanies annular dilatation in patients with ischemic mitral regurgitation.
Six sheep had radiopaque markers placed on the left ventricle, mitral leaflets and annulus, and mitral subvalvular apparatus. A pericardial patch was sutured into the middle scallop of the posterior mitral valve leaflet and furled in with a reefing stitch placed in the radial axis. Posterolateral left ventricular myocardial ischemia was created by using proximal circumflex occlusion to induce acute ischemic mitral regurgitation. Under open-chest conditions, 3-dimensional marker coordinates were measured by using biplane videofluoroscopy at baseline and during acute ischemia both before and after release of the reefing stitch (leaflet extension); transesophageal echocardiography was used to grade ischemic mitral regurgitation.
Leaflet apical systolic tethering was not improved by leaflet extension, but ischemic mitral regurgitation decreased (control, 0.9 +/- 0.3*; ischemia, 2.4 +/- 0.3; leaflet extension, 1.5 +/- 0.3; P < 0.002). Posterior mitral valve leaflet midline length (control, 1.45 +/- 0.09; ischemia, 1.53 +/- 0.10; leaflet extension, 1.83 +/- 0.13*; P < 0.001) and posterior mitral valve leaflet middle scallop area (control, 1.66 +/- 0.20 cm2; ischemia, 1.91 +/- 0.22 cm2; leaflet extension, 2.36 +/- 0.22 cm2*; *P < 0.006) increased with leaflet extension because of patch unfurling (mean +/- 1 standard error of the mean; repeated-measures analysis of variance, Dunnet post-hoc test vs ischemia).
Posterior mitral valve leaflet extension ameliorated acute ischemic mitral regurgitation but did not correct the abnormal apically restricted systolic posterior mitral valve leaflet closing motion. This technique might be a useful adjunct repair in combination with ring annuloplasty for ischemic mitral regurgitation, but the clinical role of this adjunct remains to be defined in patients.
对于采用瓣环成形环修复缺血性二尖瓣反流的患者，二尖瓣反流残留或复发的情况经常出现。由于瓣环成形主要解决瓣环扩张问题，我们研究了一种辅助技术，该技术可能纠正受限瓣叶（Carpentier IIIb型）的收缩期关闭运动，这种运动在缺血性二尖瓣反流患者中常伴随瓣环扩张出现。
对6只绵羊在左心室、二尖瓣瓣叶、瓣环及二尖瓣瓣下结构放置不透X线的标记物。将心包补片缝合至二尖瓣后叶中间扇贝形区域，并通过沿径向轴放置的缩帆缝线进行内卷。通过近端回旋支闭塞诱导急性缺血性二尖瓣反流，从而造成左心室后外侧心肌缺血。在开胸状态下，在基线时以及急性缺血期间，于缩帆缝线松解（瓣叶伸展）前后，使用双平面视频荧光透视法测量三维标记物坐标；采用经食管超声心动图对缺血性二尖瓣反流进行分级。
瓣叶伸展并未改善瓣叶尖部收缩期的受限情况，但缺血性二尖瓣反流程度减轻（对照组，0.9±0.3*；缺血时，2.4±0.3；瓣叶伸展后，1.5±0.3；P<0.002）。二尖瓣后叶中线长度（对照组，1.45±0.09；缺血时，1.53±0.10；瓣叶伸展后，1.83±0.13*；P<0.001）以及二尖瓣后叶中间扇贝形区域面积（对照组，1.66±0.20 cm²；缺血时，1.91±0.22 cm²；瓣叶伸展后，2.36±0.22 cm²*；*P<0.006）随着瓣叶伸展而增加，这是由于补片展开所致（均值±均值的1个标准误；重复测量方差分析，Dunnet事后检验与缺血情况相比）。
二尖瓣后叶伸展改善了急性缺血性二尖瓣反流，但未纠正二尖瓣后叶异常的尖部受限收缩期关闭运动。该技术可能是与瓣环成形术联合用于缺血性二尖瓣反流修复的一种有用辅助方法，但这种辅助方法在患者中的临床作用仍有待确定。
