In clinical practice, we often encounter people who have undergone tubal revascularization after ligation due to remarriage or accidental death of a child, and most of them are lucky enough to have their tubes successfully revascularized and become happy mothers again. However, there are a small number of cases where one or both tubes are reobstructed after ligation. To answer this question, we must first know that the site of ligation is at the isthmus of the fallopian tubes, where the tubes are ligated with silver clips or silk threads to close the tubal lumen so that sperm and eggs cannot meet and fertilize, thus achieving sterilization. The fallopian tubes before and after the ligation are normal and open. If the isthmus of the fallopian tube is open, the fallopian tube is normally reopened after the laparotomy. If the isthmus of the fallopian tube is obstructed, the obstruction may be caused by the growth of fibrous connective tissue at the anastomosis, and such obstruction is not suitable for interventional recanalization. If the blockage is in the distal part of the isthmus or in the umbrella, interventional recanalization can be tried. In short, an obstruction in the isthmus is not suitable for interventional recanalization; if the obstruction is in the distal part of the isthmus or in the umbrella, interventional recanalization can be tried.