胎儿镜引导下胎羊食管超声心脏监测手段的建立

Fetal lamb model of cardiac monitoring via transesophageal echocardiography guided by fetoscopy

目的探讨建立胎儿镜引导下食管超声评估胎羊心脏的监测手段，以解决宫内介入治疗先天性心脏病时影像条件不足的问题。方法取孕羊6只（zp105-119d），在体表超声探测下明确胎羊头部、四肢所在部位，评估穿刺羊膜腔部位及可行性。选择孕羊腹部前方合适位置经皮放置胎儿镜（2mm STORZ腔镜系统）至子宫内。在胎儿镜直视下寻找胎羊嘴部并进入胎羊口咽部，然后在胎儿镜引导下放置食管超声探头（心腔内超声探头）至胎羊食管，以食管超声监测胎羊心脏情况。结果6只胎羊均成功放置食管超声探头至食管，获取胎羊心脏监测数据及图像。实验前、后胎羊平均左心室每搏输出量为（3．29±1．29）ml／min和（3．12±1．24）ml／min，两者比较，差异无统计学意义（P〉0．05）。实验前、后胎羊平均右心室每搏输出量为（4．75±2．18）ml／min和（4．37±1．52）ml／min，两者比较，差异无统计学意义（P〉0．05）。结论胎儿镜引导下的胎羊食管超声监测技术可行，更能清晰显示胎羊左心系统解剖结构，心腔内超声探头应用于食管超声监测胎羊心脏情况对胎羊心脏功能影响小，相对于体表心脏超声监测存在优势。

Objective To explore the feasibility of monitoring fetal heart functions and structures via transesophageal echocardiography guided by fetoscopy in fetal lamb model. Methods A total of 6 pregnant ewes were selected. Firstly body-surface ultrasonography was performed to ascertain the positions of head and limbs for evaluating the possibility and puncture site. Then fetoscope （2 mrn STORZ endoscope system） was inserted into uterus at an appropriate site. After oropharynx was detected under fetoscope, ultrasonic probe was guided directly into esophagus to detect the cardiac structures and functions. Results All ultrasonic probes of esophagus were successfully inserted and high-quality cardiac images acquired. The stroke volume of left ventricle in fetal lamb pre-study had no significant difference with that post-study [（3.29 ±1.29） vs （3.12± 1.24） ml/min] and stroke volume of right ventricle in fetal lamb pre-study had no significant difference with that post-study [（4.75 ± 2.18） vs （4.37 ± 1.52） ml/min]. Conclusions Transesophageal echocardiography guided by fetoscope is feasible in fetal lamb model.