Endoscopic intrauterine surgery in primates - Overcoming technical obstacles

Current protocols for fetal surgery require cesarean section and partial fe tal extraction, both of which impart significant risks to the mother and fe tus. Endoscopic fetal surgery is less invasive and will likely reduce some of these risks, but the technical difficulties and feasibility in a primate model have yet to be explored fully. Four pregnant baboons (95 days gestat ion) were anesthetized, their uteruses exposed via an abdominal incision, a nd blunt-tipped flanged endoscopic ports inserted. Amniotic fluid was remov ed, and warmed saline was infused to dilate the uterus. To evaluate instrum entation and wound closure, the tip of the snout was externalized and bilat eral cleft lip-like defects made. The lips were then endoscopically repaire d by suture (Endostitch, U.S, Surgical) or unique nonpenetrating clips (VCS , U.S. Surgical). The saline was then removed, amniotic fluid returned, and the ports carefully removed. After 4 weeks, the fetuses were delivered and evaluated. Eight cleft lip-like defects were successfully repaired in all four cases. Operative time averaged 83 min. No infections, amniotic leaks, or adhesions developed. Survival was 50% with two fetuses delivering within 48 hours postoperatively: one from preterm labor, the other with fetal dem ise from retroperitoneal hemorrhage after operative blunt abdominal trauma. We demonstrate the feasibility of endoscopic fetal surgery in primates. Th e use of blunt-tipped flanged ports provides a fluid tight seal and allows appropriate closure of the fetal membranes, but requires laparotomy and ute rine exposure. Distension of the uterus with warmed saline affords a larger operating field, enhancing visualization and instrumentation of the fetus. Grasping the fetus through the exposed uterus gives excellent control for repair. However, such control is also needed in a percutaneous approach. Fu rther instrumentation development is needed to accomplish similar control f or the percutaneous approach.