术后放疗对游离皮瓣影响的实验研究

AN EXPERIMENTAL STUDY ON THE EFFECT OF THE POSTOPERATIVE RADIATION ON FREE FLAPS

目的：研究术后放疗对游离皮瓣移植后病理变化的影响，为临床提供参考。方法：采用３０只新西兰白兔制作双侧耳背皮囊，术后３周分别行７Ｇｙ，９Ｇｙ，１３Ｇｙ×４次／ｗ的６０Ｃｏ照射，放疗后不同时间内进行大体观察以及病理血管铸型检测。结果：中低剂量组３２例皮瓣全部存活，高剂量组有５例（３１．２％）发生坏死。微血管铸型显示轴血管通畅，但高剂量组皮瓣微血管密度明显降低。结论：游离皮瓣对于临床常规剂量（＜７０Ｇｙ）术后放疗具有良好的耐受性，高剂量放疗时（＞９０Ｇｙ）应慎重对待，微血管系统的破坏是皮瓣放射性损害的重要病理环节。

Objective:The effect of postoperative radiation on free flap was studied in the experiment to provide referrence for clinical use.Methods:Bilateral dorsal auricular free flaps were made on 30 New Zealand rabbits and exposed to cobalt-60 radiation 3 weeks postoperatively with fractioned doses of 7,9,13Gy×4 times within a week.After radiation,the experimental animals were detected by means of macrological observation,pathologic examination and vascular corrosion casting.Result:Total 32 cases of free flaps in low and middle-dose groups survived the postoperative radiation while five cases (31.2%)mecrozed in high-dose group.The results of vascular corrosion castings indicated pedicled vessels remained patency,but the micro-vascular density of free flap in high-dose group reduced dramatically.Conclusions:The free flap presents sufficient tolerance to postoperative radiation with clinical routine dose (〈70Gy).Care must be taken while the dose exceeds 90 Gy.The destruction of micro-vascular system is an important etiologic factor for necrosis of flap due to postoperative radiation.