胎儿血管灌注 z-bo 2020-10-15 281

　　We have a certain understanding of the vascular development of the fetus at different gestational ages, but the relationship between different interventions on the formation of blood vessels and the occurrence of congenital malformations is not clear. The vascular perfusion model of the pig fetus can be established Explore this area. In fact, our knowledge of fetal vascular anatomy in pigs is also very limited. To clarify the branches and developmental nodes of fetal blood vessels in different gestational stages on the pig model is helpful to further study the growth of fetuses in different gestational stages, the influence of anesthetics on the fetus, and surgery. The technology stimulates the development of blood vessels, which will help improve the safety of the mother and the fetus when fetal surgery is widely used clinically in the future. Miscarriage and premature delivery are currently the key issues that limit the pace of development of fetal surgery, which has also attracted wide attention from researchers. However, at present, the fetal vascular anatomy, basic fetal physiology, and the complicated relationship between the mother and the fetus are not very clear. The solution of these problems will affect the development of fetal surgery and plastic surgery in the next 10 years, whether in clinical or research. Will cause important breakthroughs. Researchers linked branches and developmental nodes in fetal blood vessel development with gestational age, and guessed its role in fetal surgery and malformations. They believe that a better understanding of the fetal blood vessel anatomy can improve the safety of the mother and the fetus. It can not only treat life-threatening congenital defects, but also perform routine fetal surgery on non-life-threatening congenital defects. The anatomical structure of the blood vessels of the fetus is different from that of adults. The transition of the blood vessel structure from the fetus to the newborn is relatively clear. However, the time course of fetal blood vessel development is not clear. This is mainly due to technical reasons. The extremely delicate mechanical operation of fetal blood vessels hinders the effective use of previous perfusion methods in fetal vascular research. For example, infusing barium sulfate into the artery branches of a 30-week-old fetus, most attempts will result in vascular rupture. The knowledge reported in the literature about fetal vascular development mainly comes from developing chickens. Although it is more valuable at the anatomical level, it is far from placental mammals. There were also previous studies on the ultrastructure of blood vessels, but not all blood vessel structures, and only involved a certain cycle rather than the whole process of pregnancy. The emergence of a new type of perfusion reagent promotes the establishment of a vascular perfusion model, namely lead oxide particles suspended in detergent-stable emulsion buffer and mineral oil. This perfusion reagent has obtained good results in the study of vascular perfusion in pig autopsy.

　　Research model example: fetal vascular perfusion model

　　(1) Experimental method: Continuous infusion of lead oxide particles in 19 fetal pigs at different developmental stages, the pressure is less than 30mmHg, there are always weak points in the fetal blood vessel structure, which may be the breakpoint of fetal malformation. It is also the basis of extravasation. Determine the extent of blood vessel development by angiography.

　　(2) Results: Comparing the head-buttock length (gestational age) and the development of the main branch blood vessels, from these data (Table 4-7), the biphasic rate of vascular development can be analyzed at 40% and 50% of the entire pregnancy. The appearance time is consistent with the first 3 months and the second 3 months of fetal development.

　　The clinical application of the porcine vascular perfusion model includes: one of the key factors for the success of fetal surgery is time, so these critical time points for the development of vascular branches should be avoided. Any interruption of the formation of this vascular network will It may disturb the initial structure and cause congenital abnormalities; for different gestational ages, the vascular structure is different and needs to be carefully delineated. This is related to improving the safety of clinical fetal surgery; the development type and development rate of blood vessels in different gestational ages are It is foreseeable that this can be used in the research of fetal blood vessel growth, angiogenesis regulation, anesthetic evaluation, and vascular response of fetal surgical trauma of different gestational ages; fetal malformations are not just bad luck, perhaps congenital defects and some parts of the fetus. The blood supply is directly or indirectly related, such as cleft deformities in the lips and palate; further understanding of fetal vascular anatomy and delineation of weaknesses in biphasic development will help us explore vascular access, anesthesia, surgery and other technologies. Thereby reducing fetal mortality and improving the safety of the fetus and the mother. However, there are still problems. Whether the data obtained on the pig model is consistent with humans needs to be further confirmed.