新生乳兔右心室超负荷模型的初步构建和分析

Preliminary Construction and Analysis of Right Ventricular Overload Model in Newborn Rabbits

目的探讨构建新生乳兔右心室(RV)超负荷模型的方法,以便研究先天性心脏病患儿RV后负荷增加的病理生理重塑过程和机制。方法选取出生当日乳兔30只,随机分为肺动脉环缩(PAB)组和假手术(Sham)组,每组各15只。PAB组于左侧第二、三肋间隙开胸,打开心包,暴露肺动脉,然后用6-0丝线环缩肺动脉;除环缩步骤外,Sham组操作同PAB组。在术后14 d进行超声心动图检测以明确肺动脉的环缩程度,通过心导管检测RV收缩压和舒张压,尔后处死动物,取心脏组织行病理学检查,以评估两组动物心脏结构大体变化和右心室游离壁厚度。结果环缩乳兔肺动脉可以显著增加RV后负荷。术后14 d时PAB乳兔存活率为80%,相对于Sham组, PAB组RV的收缩期峰值压力梯度、收缩压、舒张压和RV游离壁厚度均显著增加(P<0.01)。结论通过新生乳兔PAB手术可成功构建RV超负荷模型。

Objective To construct a neonatal rabbit model of right ventricular overload for studying the pathophysiological remodeling of right ventricle in congenital heart disease patients with right ventricular overload. Methods Thirty neonatal rabbits were selected and randomly divided into two groups. According to different surgical procedures, they were divided into surgery of pulmonary artery banding(PAB) group and sham surgery group, each group with 15 rabbits. The surgical methods of the PAB group were as follows: horizontal thoracotomy was performed through dissecting intercostal muscles and splitting the sternum along the intercostal space. Pulmonary artery was banded by a 6-0 silk thread.At 14 days after surgery, the constriction of pulmonary artery was confirmed by echocardiography. The right ventricular systolic and diastolic pressures were measured by cardiac catheterization. The histological changes of the hearts from sham and PAB group were evaluated after Hematoxylin and Eosin staining.Results Right ventricular overload was successfully established by constriction of the pulmonary artery in neonatal rabbits with the survival rate 73.33% at 14 days after surgery. Relative to a sham operation group, the peak pressure gradient across pulmonary artery constriction, right ventricular systolic and diastolic pressures, and free wall thickness were significantly increased in PAB group at 14 days after surgery(P<0.01). Conclusion The right ventricular overload model was successfully established through pulmonary arterybanding in neonatal rabbits, which may be used for studying the pathophysiological changes of congenital heart disease with right ventricular overload.