A study on a minimally invasive fetal surgery for diaphragmatic hernia

(1)胎儿外科内窥镜的发展研制了两种类型的内窥镜，一种用于胎儿观察，另一种用于胎儿气管内阻塞。外径分别为2.4 mm和3.0 mm。(2)胎儿气管内球囊导管的研制制作外径1.2mm、长5 mm、厚0.1- 0.15mm的球囊，连接外径0.7mm、内径0.3mm的硅胶管。(3)用气囊导管阻断绵羊胎儿气管内给妊娠绵羊行氟烷麻醉下的剖宫产术。在子宫壁上做一个小切口，将内窥镜的尖端通过切口插入羊水中。将乳酸林格氏液注入羊膜腔内，以获得更宽的视野。使用用于胎儿观察的内窥镜将另一个内窥镜的头端引导至胎儿脐部。然而，内窥镜引导程序因困难而被放弃。然后，由操作者的手在子宫壁的切口下方保持胎儿输卵管，并将内窥镜的尖端插入输卵管中。将头端推进到会厌以外的声带，并通过内窥镜的工作通道将球囊导管成功置入气管。

(1) Development of endoscopes for fetal surgeryTwo types of endoscope were developed ; one was for fetal observation and the other for fetal endotracheal occlusion. The outside diameter was 2.4 mm and 3.0 mm respectively.(2) Development of a balloon catheter for fetal endotracheal occlusionA balloon (1.2 mm in outside diameter, 5 mm in length and 0.1-0.15 mm in thickness) was made and connected with a silicon tube (0.7 mm in outside diameter and 0.3 mm in inside diameter).(3) Fetal endotracheal occlusion with a balloon catheter in sheepA cesarean section was performed in pregnant sheep under halothane anesthesia. A small incision was made on the uterine wall and the tip of an endoscope was inserted into the amniotic fluid through the incision. Lactated Ringer's solution was infused into the amniotic cavity for a wider field of vision. An endoscope for fetal observation was used to guide the tip of the other endoscope to the fetal nostril. However, the procedure of endoscopical guidance was abandoned because of difficulty. Thereupon, the fetal nostril was kept hold of by the operator's hands underneath the incision of the uterine wall and the tip of endoscope was inserted into the nostril. The tip was advanced beyond the epiglottis to the vocal cord and a balloon catheter was successfully placed in the trachea through the working channel of the endoscope.