The fallopian tube performs multiple functions in human reproduction and is a necessary route for sperm-egg union, and any factor affecting the transit and secretory function of the tube can affect normal pregnancy. Transvaginal non-surgical tubal embolization DD sterilization method is currently receiving attention from medical practitioners around the world, and with the development of interventional techniques, the application in the field of obstetrics and gynecology is expanding. Selective tubal cannulation is a new obstetrical and gynecological treatment technique resulting from the development of interventional techniques. In tubal embolization, the main research focus is currently on the application of embolic agents, from drug embolization to microspring coil embolization, and this paper only briefly reviews the application of tubal embolization techniques. Selective tubal cannulation technique Selective tubal cannulation technique is preferred in the treatment of tubal obstruction infertility and was first reported by Platia et al. in 1985, using a 5F polyethylene catheter with end holes and pushing its head end directly to the opening of the fallopian tube. In 1992, a homemade coaxial catheter (8F and 4F catheter) was firstly reported in China for interventional treatment. 1994, the vacuum suction cup catheter method was reported. 1996, the bulb-end catheter guidance method was reported, which was the first report on the application of bulb-end catheter for interventional treatment of tubal obstruction in China. 2000, the literature reported the double balloon catheter guidance for selective tubal cannulation technique. Selective tubal intubation technique is to insert a microcatheter with a guidewire into the fallopian tube through a guiding catheter via the vaginal uterine cavity, and then perform various treatments. One, the treatment of tubal obstruction infertility; two, the treatment of tubal pregnancy; and three, the sterilization of tubal embolization [8]. 2, History of tubal embolization As early as 1849, there were reports of successful transvaginal adhesion of silver nitrate to block the fallopian tubes, and later there were methods such as freezing method, tissue adhesion method, corrosive method, etc. to close the fallopian tubes for sterilization purposes, but all of them were not promoted because of too many side effects or too complicated surgical operations. In the late 1960s, Zipper, inspired by the tissue proliferation effect of adiponectin on human thoracic and peritoneal membranes, used adiponectin suspension to inject into the fallopian tubes of rats to stimulate the wall to proliferate, resulting in the successful closure of the fallopian tubes, and the adiponectin pills developed later were also used in clinical practice for more than 20 years. In the 1970s, the Shanghai Xinyi Pharmaceutical Factory produced a compound phenol lake agent, used for clinical results are more satisfactory. The formula of the compound phenol lake agent is 30% phenol (corrosive effect, destroying the mucous membrane of the fallopian tube), 35% adipine (promoting the proliferation of granulation tissue, making the lumen of the fallopian tube occluded), and 35% bile shadow acid (to facilitate intraoperative film or fluoroscopy to understand the drug filling situation in the fallopian tube, and the drug is usually gradually absorbed about 5 days after surgery). In the 1990s, the study of solid embolic agents in tubal sterilization was started, and success was achieved in animal experiments with metal spring coils. post et al. designed steel coils of 0.5 mm and platinum straight guide wires, each with a 3 mm end, with the flap tail located in the fallopian tube and the other end left in the uterine cavity to facilitate future removal. The technique was successful in all 10 rabbits, and no one of the rabbits had a dislodged coil. In 2005, Rosenfield et al. performed hysteroscopic embolization of the proximal portion of the fallopian tube by delivering a microspring coil through the hysteroscope with the assistance of the hysteroscope. 3. The role of tubal embolization in the management of tubal effusion prior to IVF There is a consensus on the effect of tubal effusion on IVF, which was initially used for 30 years to treat infertility caused by tubal factors. It was widely believed that because IVF treatment bypassed the damaged fallopian tubes, its pregnancy rate should be close to that of the normal population, whereas the first successful pregnancy with IVF-ET assistance in the world was actually a tubal pregnancy in 1976. hydrosalpinx was first identified and proposed to reduce the implantation rate of IVF in 1991, and many studies have shown that the presence of hydrosalpinx reduces the pregnancy rate of IVF. 1978 After the first IVF case was born in the UK, the pregnancy rate of IVF has been around 30% since then. In a retrospective analysis, IVF pregnancy rates were reduced by 50% and spontaneous abortion rates were increased twofold in cases of hydrosalpinx. In order to improve the pregnancy rate of IVF, the preoperative treatment of hydrosalpinx is the key. It is now common to pre-treat hydrosalpinx before IVF treatment, and the four methods currently used in clinical practice are tubal resection, ligation, windowing, or aspiration. The first two have surgical risks and are prone to damage the uterine ovarian vessels and have an impact on the ovarian blood supply. Some studies have shown that the ovary on the side of tubal resection during IVF has low responsiveness to superovulation treatment; the latter two are prone to recurrence of hydrocele and have a higher tubal pregnancy rate. Interventional treatment with tubal embolization can avoid both the risk of surgery and the alteration of ovarian blood supply, as well as the recurrence of tubal pregnancy and tubal effusion. 4. The application of microspring coils in tubal embolization interventions Tubal drug embolization is prone to cause chemical peritonitis and changes to the intrauterine environment, which is not suitable for the treatment of hydrosalpinx before IVF. Proximal tubal embolization with microspring coils is mechanical and does not alter the intrauterine environment. A selective tubal cannula is first used to deliver the spring coil through a microcatheter into the interstitial tubules and isthmus. The microspring coil is made of platinum alloy and is used clinically for vascular embolization. The wire diameter of the spring coil is 0.018in (0.45mm), the length of the spring coil is 30-50mm when straightened and 3-5mm when curled, the spring coil has a villi attached to it to increase the compatibility with the tubal wall. Mechanism of action: (1) complete mechanical blockage of the tubal lumen; (2) change of the local microenvironment of the embolization, due to the release of alkaline phosphatase from the mild mechanical necrotic tissue caused by the implantation, causing auxiliary lymphocyte aggregation and proliferation of fibrovascular tissue to strengthen the tubal lumen obstruction; (3) the spring steel wire with villi attached to it, increasing the compatibility with the tubal lining. The advantage is that it does not damage the arterial arch in the fallopian tube tract, does not affect the blood supply to the ovarian arteries, and improves the pregnancy rate of IVF. Rosenfield et al. performed a case of tubal embolization with hysteroscopic insertion of a microspring coil into the proximal portion of the fallopian tube, followed by IVF and delivery of twin fetuses by cesarean section at 34 weeks. It was demonstrated that hysteroscopic placement of a microspring coil into the proximal part of the fallopian tube may be an alternative treatment to laparoscopic proximal tubal obstruction or tubectomy for patients with hydrocele who want to undergo IVF. A group of data from the author: Under X-ray surveillance, a microspring coil was delivered into the proximal fallopian tube by selective tubal cannulation to embolize the hydronephrosis tube in 36 patients, 25 patients underwent bilateral tubal embolization and 11 patients underwent unilateral tubal embolization. One month after tubal embolization, hysterosalpingography was performed, and 61 tubes were shown to be effective, accounting for 100.00%. Among them, 42 tubes (82.35%) showed the best results. The number of ineffective cases was 0%. Efficacy evaluation criteria: Hysterosalpingography was performed one month after tubal embolization to observe the position of the microspring ring in the fallopian tube, as well as the degree of blockage of the fallopian tube and whether the contrast agent entered the distal end of the fallopian tube. ①Best results: Hysterosalpingography showed that the microspring ring was in the fallopian tube and its proximal end was within 10 mm of the ionophore opening, and the contrast agent could not enter the distal end of the fallopian tube. ②Effective: Hysterosalpingography showed that the microspring coil was within the fallopian tube and the proximal end of the tube showed 10-30mm, and the contrast agent could not enter the distal end of the tube. (iii) Ineffective; hysterosalpingography showed that the microspring coil was in the fallopian tube and the contrast agent could enter the distal part of the tube, or the microspring coil was leaking into the umbilical end of the tube or the uterine cavity. When comparing the intra-operative indicators of tubal embolization with those of the control group (those without tubal effusion), there was no significant difference in the number of eggs obtained, fertilization rate, and clinical pregnancy rate, but there was a significant difference in the ectopic pregnancy rate and miscarriage rate, which eliminated ectopic pregnancy and reduced the miscarriage rate. It was concluded that for patients with hydrosalpinx who want to undergo IVF, microspring coil placement into the proximal blocked hydrosalpinx is at least another alternative treatment to tubectomy and is effective. 5. Prospects for interventional treatment of tubal embolism Nowadays, patients suffering from infertility are increasing year by year, and the use of in vitro fertilization-embryo transfer is expanding. The impact of tubal effusion on IVF has been agreed upon, and how to pretreat tubal effusion before IVF is a matter of urgent concern. After tubal embolization, the fertilization rate and egg cleavage rate in IVF treatment cycle are similar to those of patients with proximal tubal obstruction without hydrosalpinx. Compared with the four methods currently used in clinical practice, it is simple, safe, economical, has no complications from surgical anesthesia, has no effect on ovarian function, fills a gap in the application of interventional treatment in in vitro fertilization-embryo transfer, and is a new breakthrough in the development of in vitro fertilization-embryo transfer with a significant increase in pregnancy rate. . And it can eliminate the occurrence of tubal pregnancy. It has a very good development prospect.