目的    探讨不同时长及缺血程度的延迟术式对皮瓣存活的影响。 方法   125只成年ICR小鼠随机等分为5组。对照组切取以髂腰血管为蒂的4.5 cm×1.5 cm皮瓣。4个延迟组按照延迟时间与切断胸背动脉尾侧支与否分为留血管7 d组与14 d组及切血管7 d与14 d组。在延迟结束后，建立与对照组同样的皮瓣模型。之后，计算皮瓣的坏死率，并用激光散斑衬比成像仪测量皮瓣的动脉管径及血流灌注、以及利用CD31抗体标示皮瓣内的血管。利用单因素方差分析对各组数据进行统计学比较。 结果   术后7 d各延迟组的皮瓣坏死率均小于对照组(P<0.001)。4个延迟组蒂部与choke动脉管径及灌注强度都显著大于对照组（P<0.05）。两切血管组皮瓣存活率、蒂部与choke动脉管径、血流灌注强度均显著大于两留血管组(P<0.05)；延迟7 d组之间与延迟14 d组之间各项指标的差异没有统计学意义(P>0.05)。术后0 d，4组延迟皮瓣的血管密度显著大于对照组(P<0.001)，但术后7 d各组皮瓣的血管密度没有统计学差异（P=0.883）。  结论    延迟只需要7 d便能达到最佳效果。此外，延迟期间应尽量使皮瓣处于缺血最严重但不致组织坏死的状态。

Objective    To investigate the effect of delayed surgery with different length and various degrees of ischemia on flap survival.    Methods    125 adult ICR mice were randomly divided into 5 groups. In the control group, flaps based on iliolumbar vessels with a size of 4.5 cm×1.5 cm were established. The four delayed groups were divided into vessels-preserved 1- and 2-week delay groups and vessels-transected 1-and 2-week delay groups. After the delay, the same flap model as the control group was established. Then, the necrosis rate of the flap was calculated, the arterial diameter and blood perfusion of the flap were measured by a laser speckle imaging device, and the blood vessels in the flap were marked by a CD31 antibody. The data of each group were statistically compared by one-way ANOVA.    Results    7 days after operation, the flap necrosis rate in each delayed group was lower than that in the control group (P<0.001). The diameter and perfusion intensity of the pedicle and the choke area in the four delayed groups were significantly higher than those in the control group (P<0.05). The survival rate of the flap, the diameter of the pedicle and choke arteries, and the blood perfusion intensity in the two vessels-transected groups were significantly higher than those in the two vessels-preserved groups (P<0.05); There was no significant difference in the various parameters between the 1-week delay group and the 2-week delay group (P>0.05). At 0 days after surgery, the vascular density in the four delayed groups was significantly higher than that in the control group (P<0.001), but there was no significant difference at 7 days after surgery (P=0.883).     Conclusion    The best efficacy can be achieved by delaying only one week. In addition, during the delay period, the flap should be in the state of the most serious ischemia without tissue necrosis.