中文摘要：

目的通过腹主动脉腔内低压力灌注猪胰弹力蛋白酶建立兔腹主动脉瘤模型,探索不同浓度猪胰弹力蛋白酶对兔腹主动脉成瘤率的影响。方法新西兰雄兔50只,体质量（2.50±0.20）kg,随机分为5组：A组、B组、C组、D组、E组,每组各10只。A组经双腔导管注入生理盐水10μl,其余4组经双腔导管注入10μl浓度分别为1U/ml、10U/ml、100U/ml、200U/ml的猪胰弹力蛋白酶,灌注保持7min。术后第7天处死动物,分别于术前及术后第7天行腹主动脉彩超检查,观察灌注血管部位变化。结果 E组实验动物存活率较A组、B组、C组及D组明显下降（40%vs 90%、90%、90%及90%）。腹主动脉术后最大直径随给予灌注浓度增加而增大。与术前最大直径比较,A组及B组术后最大直径未见明显扩张;C组、D组及E组术后最大直径明显扩张;D组及E组较A组、B组及C组,术后第7天腹主动脉扩张率[（125.40±16.10）%及（248.20±5.60）%vs 0%、（24.90±2.50）%及（43.90±7.69）%,P〈0.05]及成瘤率[100.0%及100.0%vs 0%、0%及33.3%,P〈0.05]均明显升高。结论高浓度猪胰弹力蛋白酶（100U/ml）在低压力状态下较短时间灌注可成功建立兔腹主动脉瘤模型,且成瘤率高、死亡率低。

英文摘要：

Objective To study the effect of different elastase levels on abdominal aortic aneurysm（AAA）formation in rabbits by establishing a rabbit AAA model through perfusion of pig elastase under low pressure.Methods Fifty male New Zealand white rabbits were randomly divided into groups A—E（10in each group）.Tenμl normal saline was injected into group A and 10μl elastase at the concentration of 1U/ml,10U/ml,100U/ml,and 200U/ml was respectively injected into groups B-E through a double-lumen catheter for 7minutes.The animals were killed on day 7after operation.The stained abdominal aorta tissue sample was observed by Doppler ultrasonography before operation and on day 7after operation.Results The survival rate was significantly lower in group E than in groups A—D.The maximal diameter of abdominal aorta after operation increased with the inceasing elastase concentration.No significant dilation of the maximal abdominal aorta diameter was found between groups A and B before operatiom.However,the maximal abdominal aorta diameter was significantly dilated in groups C—E after operation.The dilation rate of abdominal aorta and AAA formation rate were signifiocantly higher in groups D and E than in groups A—C on day 7after operation.Conclusion A rabbit AAA model can be established by short-term perfusion of pig elastase at the concentration of 100 U/ml under low pressure,which is characterized by a high aneurysm formation rate and a low mortality.