Gates R N, Laks H, Drinkwater D C, Ardehali A, Aharon A S, Zaragoza A M, Chang P A
Department of Surgery, University of California, Los Angeles, Medical Center 90024, USA.
Ann Thorac Surg. 1995 Nov;60(5):1308-11. doi: 10.1016/0003-4975(95)00645-2.
The complete and uniform distribution of cardioplegia to the microvasculature of the heart is considered critical for myocardial protection. This study explores the hypothesis that enhanced microvascular perfusion can be achieved by using both antegrade and retrograde cardioplegia.
Infant piglet hearts (n = 15) were arrested with antegrade blood cardioplegia, excised, and fixed with 2.5% glutaraldehyde by retrograde perfusion. Hearts were then perfused retrograde with an inert intracapillary marker (NTB-2). Six of these hearts served as controls (group 1) to anatomically demonstrate the degree of capillary perfusion achieved by the retrograde delivery route. Nine experimental hearts (group 2) underwent a subsequent infusion of antegrade blood cardioplegia to wash out NTB-2 capillaries coperfused by both the antegrade and retrograde delivery techniques. Sections of the left ventricular free wall and anterior-mid interventricular septum were taken and examined by light microscopy at four separate sites (average, 126 capillaries per section).
In control hearts, 91.9% +/- 0.9% of ventricular capillaries and 91.4% +/- 5.8% of septal capillaries were perfused by retrograde cardioplegia. After antegrade blood cardioplegia washed out group 2 hearts, 14.0% +/- 4.1% of capillaries in the ventricle still contained NTB-2, as did 12.5% +/- 5.4% of capillaries in the septum.
In this experimental model, antegrade blood cardioplegia did not coperfuse (and therefore washout) 12.5% to 14% (p < 0.05) of capillaries perfused by retrograde cardioplegia. This suggests that an additional 12.5% to 14% of capillaries within the myocardium may receive cardioplegia if retrograde cardioplegia is used in addition to antegrade cardioplegia. We conclude that by combining both antegrade and retrograde cardioplegia, there is a potential for enhanced overall microvascular perfusion.
心脏停搏液在心脏微血管中的完全且均匀分布被认为对心肌保护至关重要。本研究探讨了通过顺行和逆行心脏停搏液灌注可实现增强微血管灌注的这一假设。
用顺行血液心脏停搏液使15只幼猪心脏停搏，切除后通过逆行灌注用2.5%戊二醛固定。然后用惰性毛细血管标记物（NTB - 2）对心脏进行逆行灌注。其中6只心脏作为对照组（第1组），用于从解剖学上证明逆行灌注途径实现的毛细血管灌注程度。9只实验心脏（第2组）随后进行顺行血液心脏停搏液灌注，以冲洗掉由顺行和逆行灌注技术共同灌注的含有NTB - 2的毛细血管。取左心室游离壁和室间隔前中部的切片，在四个不同部位进行光学显微镜检查（平均每组切片126条毛细血管）。
在对照心脏中，91.9%±0.9%的心室毛细血管和91.4%±5.8%的间隔毛细血管通过逆行心脏停搏液灌注。在第2组心脏经顺行血液心脏停搏液冲洗后，心室中14.0%±4.1%的毛细血管仍含有NTB - 2，间隔中12.5%±5.4%的毛细血管也含有NTB - 2。
在该实验模型中，顺行血液心脏停搏液并未与逆行心脏停搏液共同灌注（因此也未冲洗掉）12.5%至14%（p<0.05）由逆行心脏停搏液灌注的毛细血管。这表明，如果除了顺行心脏停搏液外还使用逆行心脏停搏液，心肌内可能另有12.5%至14%的毛细血管会接受心脏停搏液。我们得出结论，通过联合使用顺行和逆行心脏停搏液，有可能增强整体微血管灌注。
