Angel M F, Knight K R, Biavati M J, Mellow C G, Wanebo J, Amiss L R, Morgan R M
Department of Plastic Surgery, University of Virginia.
J Reconstr Microsurg. 1991 Oct;7(4):335-7. doi: 10.1055/s-2007-1006793.
The first ischemic insult a tissue suffers is primary (1 degree) ischemia. A second ischemic episode, such as thrombosis after free tissue transfer, may be regarded as secondary (2 degrees) ischemia. Timing relationships were studied in a rodent epigastric-flap model. In a first experiment, the interval between 1 degree ischemia and 2 degrees ischemia was varied. Flaps which had 2 degrees ischemia 12 and 36 hr after the 1 degree episode, had decreased ischemic tolerance, compared with 1 degree ischemic flaps; 2 degrees ischemic flaps, after an interval of 72 hr, had an ischemic tolerance similar to 1 degree ischemic flaps. In a second experiment, the length of the 1 degree ischemia was varied. It was found that as little as 5 min of 1 degree ischemia significantly decreased the subsequent tolerance of 2 degrees ischemia. The possible clinical significance of these results is discussed.
组织遭受的首次缺血性损伤为原发性（1级）缺血。第二次缺血发作，如游离组织移植后的血栓形成，可视为继发性（2级）缺血。在啮齿动物上腹部皮瓣模型中研究了时间关系。在第一个实验中，改变1级缺血和2级缺血之间的间隔时间。在1级发作后12小时和36小时出现2级缺血的皮瓣，与1级缺血皮瓣相比，缺血耐受性降低；间隔72小时后，2级缺血皮瓣的缺血耐受性与1级缺血皮瓣相似。在第二个实验中，改变1级缺血的时长。结果发现，仅5分钟的1级缺血就会显著降低随后对2级缺血的耐受性。讨论了这些结果可能的临床意义。
