Stevens D M, Weiss D D, Koller W A, Bianchi D A
Department of Otolaryngology--Head and Neck Surgery, National Naval Medical Center, Bethesda, Maryland, USA.
Otolaryngol Head Neck Surg. 1996 Oct;115(4):360-4. doi: 10.1016/S0194-5998(96)70051-7.
Although hyperbaric oxygen has been shown to improve the survival rate of ischemic grafts and flaps of many types, it has not been studied extensively in free tissue transfer. This study was designed to evaluate the effect of hyperbaric oxygen on flap survival when exposed to critical combinations of primary ischemia, reperfusion, and secondary ischemia times. Unilateral abdominal adipocutaneous island flaps based on the superficial inferior epigastric vessels were raised in 133 Sprague-Dawley rats. Primary normothermic ischemia was induced by applying a microvascular clamp to the vascular pedicle for 6 hours. The clamp was removed for 2 hours of reperfusion and then reapplied for a 6-, 10-, or 14-hour period of secondary ischemia. After completion of the secondary ischemia time, the clamp was removed, and the animals were randomly assigned to one of three treatment regimens. The control animals breathed normobaric air, and the others breathed normobaric 100% oxygen or hyperbaric oxygen (100% oxygen at the equivalent of 33 feet of seawater, 2.0 atmospheres absolute), respectively, for two periods of 90 minutes for 7 days. Flap survival was assessed at postoperative day 7 and was found to be an all-or-none phenomenon. Maximum likelihood-derived survival curves were fitted to the data and used to calculate the secondary ischemic time at which 50% of the flaps survived (D50). The D50 for the air and 100% oxygen groups was 6 hours, whereas that for the hyperbaric oxygen group was 10 hours. This difference in D50 was found to be statistically significant (analysis of variance, p < 0.05). Chi-squared statistical evaluation of pooled data reaffirmed a statistically significant increase in flap survival of the animals treated with hyperbaric oxygen vs. those treated with air or 100% oxygen (p < 0.03 and p < 0.01, respectively). Hyperbaric oxygen enhances the tolerance of normothermic, microvascular flaps to prolonged secondary ischemia. A similar effect was not noted in the 100% oxygen group; therefore the additional expense and technology of a hyperbaric chamber system is necessary to achieve this effect.
尽管高压氧已被证明可提高多种类型缺血移植物和皮瓣的存活率，但在游离组织移植中尚未得到广泛研究。本研究旨在评估高压氧对皮瓣在经历原发性缺血、再灌注和继发性缺血时间的关键组合时存活率的影响。在133只Sprague-Dawley大鼠中掀起以腹壁下浅血管为蒂的单侧腹部脂肪皮岛瓣。通过对血管蒂施加微血管夹6小时诱导原发性常温缺血。移除夹子进行2小时再灌注，然后重新施加夹子进行6、10或14小时的继发性缺血。继发性缺血时间结束后，移除夹子，将动物随机分配到三种治疗方案之一。对照动物呼吸常压空气，其他动物分别呼吸常压100%氧气或高压氧（相当于33英尺海水深度的100%氧气，绝对压力2.0个大气压），分两个90分钟时段，持续7天。在术后第7天评估皮瓣存活情况，发现其为全或无现象。将最大似然法得出的存活曲线拟合到数据中，并用于计算50%皮瓣存活时的继发性缺血时间（D50）。空气组和100%氧气组的D50为6小时，而高压氧组为10小时。发现D50的这种差异具有统计学意义（方差分析，p<0.05）。对汇总数据的卡方统计评估再次证实，与呼吸空气或100%氧气的动物相比，接受高压氧治疗的动物皮瓣存活率有统计学意义的增加（分别为p<0.03和p<0.01）。高压氧可增强常温微血管皮瓣对延长的继发性缺血的耐受性。在100%氧气组中未观察到类似效果；因此，要实现这种效果，高压氧舱系统的额外费用和技术是必要的。
