In the urinary system, the kidneys produce urine, which is collected through the tubes in the kidneys and then discharged through the ureters to the bladder for storage, and then excreted through the urethra after reaching a certain amount. Although the urinary drainage ducts themselves have no function, narrowing of the ducts results in poor urine drainage, leading to hydronephrosis, which may have a significant impact on kidney function, and in severe cases, lead to loss of kidney function. Abnormalities of the urinary ducts are mainly manifested as stenosis or leakage of urine, with stenosis again being the mainstay. There are many reasons for urinary tract stenosis, mainly including: 1, congenital developmental abnormalities, that is, developmental defects, born with a narrow tube; 2, acquired diseases leading to tube stenosis, such as stones blocking the tube, the tube long tumors or inflammation and swelling of the tube can lead to lumen thinning, affecting the urine drainage, leukemia chemotherapy or bone marrow transplantation ureteral stenosis is also relatively common; 3, outside the tube disease invasion or Pressure on the ureter, such as gynecological tumor radiotherapy, intestinal tumors, retroperitoneal tumors and other invasion or pressure on the ureter; 4, trauma, especially urethral injury, commonly caused by falling from height or car accidents, etc.; 5, medical factors lead to pipeline injury and stenosis, due to the thin wall of urinary catheter, the need to do endo-luminal surgery with the need to pass through the urinary catheter, and sometimes need to be repeatedly in and out of urinary catheter, which may result in injury and lead to pipeline stenosis. In addition, the treatment of diseases in the ducts, such as stones or tumors, may also cause duct damage and narrowing. Therefore, minimally invasive surgery is not minor surgery, let alone non-invasive surgery, it only means that the damage is reduced compared to the previous traditional surgery, but the minimally invasive surgery itself may also have serious complications. Strictures due to injury or disease of the ureter itself are most often associated with scarring, and current technology is not able to restore the scarring to normal. The solution to scarring usually requires its removal. After the removal of a long scarred ureteral stricture, the defect is so long that the remaining tube cannot be connected directly and requires an external tube, and there is a lack of a perfect alternative material to use as an external tube for ureteral repair. This is the main reason why ureteral stenosis is not well treated.