门控心肌灌注和心肌代谢显像评价新方法制作小型猪室壁瘤模型的可行性

目的 应用门控心肌灌注和心肌代谢显像评价新方法建立小型猪室壁瘤模型的可行性。方法 中华小型猪16只,采用结扎冠状动脉钝缘支远端,并在左前降支(LAD)第1对角支分叉处以下1cm处放置Ameroid 环的方法建立模型。在建模后第4周采用门控心肌灌注/代谢显像观测左心室灌注受损情况(TPD)、存活心肌占左心室百分比(Mismatch)、室壁瘤形成情况以及左心室射血分数(LVEF)、左心室舒张末期容积(EDV)、左心室收缩末期容积(ESV)等指标。建模后第8周处死动物,取病理结果进行分析。结果 建模总体病死率为31.2% (11/16),病理结果证实,8头小猪心尖部有室壁瘤形成。8头小猪完成术后第4周显像,显像结果提示,6头小猪心尖部有室壁瘤形成,2头小猪仅呈现非透壁性心肌梗死表现。与心肌梗死组获得的参数相比较,室壁瘤组的左心室灌注总受损范围(TPD)、舒张末期容积(EDV)、收缩末期容积(ESV)明显增高,左心室射血分数(LVEF)及存活心肌百分比(Mismatch)明显下将,差异有统计学意义(P<0.05)。结论 通过门控心肌灌注和心肌代谢显像评价结扎冠状动脉钝缘支远端并在左前降支第1对角支下1cm处放置Ameroid 环的方法,是比较理想的建立室壁瘤模型的方法,该方法操作简单、可行,建模成功率高,动物存活率满意,建模后第4周左心室重构明显。

A New Method to Make Left Ventricular Aneurysm Pig Model with Obvious Ventricular Dysfunction and Remodeling as Evaluated by Gated 99mTc-MIBI SPECT Perfusion and Gated 18F-FDG PET Metabolic Imaging

Objective To assess a new method for establishment of pig model with left ventricular aneurysm(LVA) leading to left ventricular (LV) dysfunction and remodeling by gated ^99mTc-MIBI SPECT perfusion (GSPECT) and gated ¹⁸F-FDG PET metabolic (GPET) imaging. Methods Sixteen Chinese Mini-Pigs were included in our study and LV Aneurysm was induced by occlusion of left circumflex artery (LCX) and then placing an ameroid constrictor at proximal left anterior descending artery (LAD). On the 4^th week after surgery, total perfusion defect(TPD), percentage of viable myocardium (Mismatch), LV ejection fraction (LVEF), end diastolic volume (EDV) and end systolic volume (ESV) were evaluated by GSPECT and GPET.LV aneurysm was defined as with one or more dyskinetic or akinetic and with wall thickening disappeared myocardial segments revealed by GPET. Results The death rate was 31.2% (11/16) in surgery, the survival rate was 100% and 54.5% respectively on the 1^st and on the 4^th week. LV aneurysms were confirmed in eight pigs on the 8^th week by pathological results.Eight pigs took part into GSPECT and GPET imaging protocol and were divided into two groups according to imaging results on the 4^th week after surgery. Compared with myocardial infarction(MI) group, there was progressive increase in left ventricular end diastolic volume (LVEDV) and left ventricular end systolic volume (LVESV) at LV aneurysm group (P<0.05). LV ejection fraction (LVEF) and percentage of viable myocardium were significantly decreased at LV aneurysm group (P<0.05). Conclusion Through GSPECT and GPET imaging,we found that ligation of the distal end of LCX and installation an ameroid constrictor at the proximal LAD play an important role in establishing LV aneurysm pig model, accompanied with obvious LV remodeling.