Nicolosi A C, Weng Z C, Detwiler P W, Spotnitz H M
Department of Surgery, Columbia University College of Physicians and Surgeons, New York, N.Y. 10032.
J Thorac Cardiovasc Surg. 1990 Nov;100(5):745-55.
Patch reconstruction of left ventricular aneurysm may be superior to linear closure, but this hypothesis has not been tested experimentally. Accordingly, six anesthetized domestic pigs were instrumented to measure regional left ventricular wall thickening, stroke volume, systolic left ventricular pressure, and myocardial oxygen consumption. With total bypass and cardioplegia, a 6 by 8 cm Dacron patch was inserted into the anteroapical left ventricle. Simulations were as follows: left ventricular aneurysm, patch open; patch reconstruction, 50% patch plication; standard repair, ventriculotomy edges approximated. Global function, from stroke work (stroke volume x integral of left ventricular pressure)-left ventricular end-diastolic pressure curves, was depressed in all three simulations compared with control. A tendency for stroke work to be greater for standard repair than for left ventricular aneurysm and patch reconstruction at higher preloads was not statistically significant. Mechanical efficiency, from stroke work/myocardial oxygen consumption (joules per milliliter oxygen per beat), was 2.43 +/- 0.52 (mean +/- standard error of the mean) (control), 2.22 +/- 0.94 (standard repair), 1.27 +/- 0.39 (patch reconstruction), and 1.09 +/- 0.37 (left ventricular aneurysm) (no significant differences). Regional work was calculated as regional left ventricular wall thickening x integral of left ventricular pressure. The slope of the regional work-end-diastolic wall thickness relation decreased in the posterior wall 14.0 +/- 2.9 (control) versus 8.4 +/- 2.0 (left ventricular aneurysm), 6.9 +/- 1.4 (patch reconstruction), and 7.4 +/- 1.4 (standard repair) (p less than 0.05). In the anterior wall, contractility did not change significantly (7.4 +/- 1.2, control; 7.8 +/- 2.7, left ventricular aneurysm; 5.0 +/- 0.4, patch reconstruction; and 5.3 +/- 0.4, standard repair). Decreased end-diastolic wall thinning anteriorly suggested tethering. These results in the normal left ventricle suggest that patch ventriculoplasty is of no greater benefit than linear repair. Either repair may impede function of adjacent myocardium through restriction of regional diastolic lengthening.
左心室动脉瘤的补片重建可能优于线性闭合，但这一假设尚未经过实验验证。因此，对6只麻醉的家猪进行仪器植入，以测量局部左心室壁增厚、每搏输出量、左心室收缩压和心肌耗氧量。在完全体外循环和心脏停搏的情况下，将一块6×8厘米的涤纶补片插入左心室前尖部。模拟情况如下：左心室动脉瘤，补片开放；补片重建，补片折叠50%；标准修复，心室切口边缘对合。与对照组相比，在所有三种模拟情况下，根据每搏功（每搏输出量×左心室压力积分）-左心室舒张末期压力曲线得出的整体功能均降低。在较高前负荷下，标准修复的每搏功有高于左心室动脉瘤和补片重建的趋势，但无统计学意义。机械效率由每搏功/心肌耗氧量（每搏每毫升氧的焦耳数）得出，分别为2.43±0.52（平均值±平均标准误差）（对照组）、2.22±0.94（标准修复）、1.27±0.39（补片重建）和1.09±0.37（左心室动脉瘤）（无显著差异）。局部功计算为局部左心室壁增厚×左心室压力积分。后壁局部功-舒张末期壁厚度关系的斜率降低，分别为14.0±2.9（对照组）、8.4±2.0（左心室动脉瘤）、6.9±1.4（补片重建）和7.4±1.4（标准修复）（p<0.05）。在前壁，收缩性无显著变化（7.4±1.2，对照组；7.8±2.7，左心室动脉瘤；5.0±0.4，补片重建；5.3±0.4，标准修复）。前壁舒张末期壁变薄减少提示有牵拉。在正常左心室中的这些结果表明，补片心室成形术并不比线性修复有更大益处。两种修复方式都可能通过限制局部舒张期延长而妨碍相邻心肌的功能。
