Basic research for fetal cardiac surgery

背景：建立安全的胎儿心脏搭桥是实施胎儿心脏手术干预的必要条件。我们研究了与胎儿心脏搭桥相关的脐血管凋亡。方法：以13只怀孕母羊为研究对象。将胎羊分为心脏旁路组（CB）和对照组（n=6）。在CB组，使用离心泵维持心脏旁路30分钟。旁路手术后，观察胎儿60分钟，然后切除脐动脉。对照组行假手术，切除脐动脉。脐动脉组织样本用于TUNEL研究和细胞色素c、Bax、Bcl-2、Bcl-xL和Caspase 3的western blotting。结果：两组脐动脉tunel阳性核数相似（CB组每高倍视野阳性核数0.57±0.29，对照组0.33±0.21,p=0.37）。两组患者总caspase 3水平差异无统计学意义（CB组1.40±0.43，对照组0.99±0.09,p=0.39）。两组均未检测到Cleaved caspase 3。两组患者胞浆细胞色素c水平差异无统计学意义（CB组1.99±0.75，对照组2.80±1.41,p = 0.60）。两组患者Bax/Bc1-2比值（CB组1.66±0.66，对照组1.49±0.32,p = 0.83）差异无统计学意义。两组患者Bcl-xL水平差异无统计学意义（CB组0.59±0.07，对照组0.58±0.10,p=0.93）。结论：我们已经证明胎儿CB没有在脐带动脉中触发额外的凋亡信号，这表明胎儿心脏手术后脐带血管可能通畅

Background : To establish the safe fetal cardiac bypass is mandatory to perform the fetal cardiac surgical interventions. We investigated apoptosis in umbilical vessels related to fetal cardiac bypass. Methods : Thirteen pregnant ewes were used in the present study. Fetal lambs were divided into the cardiac bypass (CB) group (n=7) and the control group (n=6). In the CB group, cardiac bypass was maintained for 30 minutes using a centrifugal pump. After bypass, the fetuses were observed for 60 minutes and then the umbilical artery was harvested. In the control group, sham operation was performed and the umbilical artery was harvested. Umbilical artery tissue samples were used for TUNEL study and western blotting for Cytochrome c,Bax,Bcl-2,Bcl-xL, and Caspase 3. Results : The TUNEL-positive nuclei in umbilical artery were similar in both groups (CB group 0.57±0.29,control group 0.33±0.21 positive nuclei per high-power field, p=0.37). There were no significant differences in total caspase 3 levels between the 2 groups (CB group 1.40±0.43,control group 0.99±0.09,p=0.39). Cleaved caspase 3 were not detected in both groups. There were no significant differences in cytosolic cytochrome c levels between the 2 groups (CB group 1.99±0.75, control group 2.80±1.41,p = 0.60). There were no significant differences in Bax/Bc1-2 ratio between the 2 groups (CB group 1.66±0.66,control group 1.49±0.32,p = 0.83). There were no significant differences in Bcl-xL levels between the 2 groups (CB group 0.59±0.07,control group 0.58±0.10,p=0.93). Conclusions : We have demonstrated that fetal CB have not triggered additional apoptotic signals in the umbilical artery, suggesting that umbilical vessels may be patent after fetal cardiac surgery