Okamoto F, Allen B S, Buckberg G D, Bugyi H, Leaf J
J Thorac Cardiovasc Surg. 1986 Sep;92(3 Pt 2):613-20.
This study tests the hypothesis that more muscle salvage after acute ischemia is possible by "gentle," temporary reperfusion than with sudden, complete revascularization. Ten dogs underwent 4 hours of left anterior descending coronary artery ligation with reperfusion during total vented bypass for 1 hour of the 2-hour reperfusion period. In five dogs, reperfusion was accomplished by release of the occlusion suddenly and completely. The five others received selective low-pressure (40 to 50 mm Hg) coronary reperfusion with normal blood for 20 minutes at 30 ml/min before the occlusion was relieved completely. Systolic shortening with ultrasonic crystals, triphenyltetrazolium chloride staining, and myocardial wet and dry weights were measured. Sudden relief of occlusion failed to restore contractility spontaneously (-7 +/- 1% systolic shortening, p less than 0.05) or with inotropic infusion (-2 +/- 4% systolic shortening, p less than 0.05) and caused the greatest amount of edema (82.2%, systolic shortening, p less than 0.05) and triphenyltetrazolium chloride nonstaining (76% area at risk, p less than 0.05). In contrast, temporary, gentle reperfusion allowed slight spontaneous recovery in four of five hearts (4 +/- 2% systolic shortening), increasing to 26 +/- 12% systolic shortening (p less than 0.05) with inotropic stimulation, limited edema (80.7%, p less than 0.05), and reduced triphenyltetrazolium chloride nonstaining to 55% (p less than 0.05). Early temporary, gentle reperfusion limits the postischemic damage that occurs with sudden, complete revascularization (aortic unclamping without control of reperfusion pressure or flow). These findings may have implications during revascularization for acute myocardial infarction when perfusion pressure and flow can be controlled.
本研究检验了这样一种假设，即与突然、完全的血管再通相比，通过“温和的”临时再灌注在急性缺血后挽救更多肌肉是可能的。十只狗在完全通气旁路的情况下，左前降支冠状动脉结扎4小时，在2小时再灌注期的1小时内进行再灌注。五只狗通过突然完全解除阻塞来实现再灌注。另外五只狗在完全解除阻塞前，以30毫升/分钟的速度用正常血液进行选择性低压（40至50毫米汞柱）冠状动脉再灌注20分钟。用超声晶体测量收缩期缩短、用氯化三苯基四氮唑染色，并测量心肌湿重和干重。突然解除阻塞未能自发恢复收缩力（收缩期缩短-7±1%，p<0.05）或在使用正性肌力药物输注时恢复（收缩期缩短-2±4%，p<0.05），并导致最大量的水肿（82.2%，收缩期缩短，p<0.05）和氯化三苯基四氮唑不着色（76%的危险区域，p<0.05）。相比之下，临时、温和的再灌注使五只心脏中的四只出现轻微的自发恢复（收缩期缩短4±2%），在正性肌力刺激下增加到收缩期缩短26±12%（p<0.05），水肿有限（80.7%，p<0.05），氯化三苯基四氮唑不着色减少到55%（p<0.05）。早期临时、温和的再灌注限制了突然、完全血管再通（在不控制再灌注压力或流量的情况下解除主动脉夹闭）时发生的缺血后损伤。当灌注压力和流量可以控制时，这些发现可能对急性心肌梗死的血管再通有影响。
