Patient: Hydronephrosis caused by congenital ureteral stenosis was found during B-ultrasound in 2001. After many tests, the degree of hydronephrosis changed from the original left kidney to double hydronephrosis. The left kidney had more hydronephrosis than the right kidney. Song Shaokang, Department of Urology, Henan Provincial People's Hospital: Pelvic-ureteral junction stenosis is the most common site of ureteral stenosis, and its causes are diverse, such as congenital developmental abnormalities, ureteral inflammatory stenosis and twist, ureteral valve, vagal compression, etc. Although the causes are different, the pathophysiological processes are basically the same, that is, due to mechanical or dynamic factors, urine transmission at the renal pelvic ureteral junction is gradually blocked, causing retention in the renal pelvis, and the pressure in the renal pelvis, renal interstitium, and collecting duct gradually increases. Increases lead to nephron damage, renal parenchyma gradually shrinks and becomes thinner, is replaced by fibrous tissue, and hydronephrosis expands. This may be complicated by infection and stone formation, eventually leading to progressive destruction and loss of kidney function. Song Shaokang, Department of Urology, Henan Provincial People's Hospital: Although the success rate of open dissociated pyeloplasty exceeds 90%, it has the widest indications and the best long-term results and is known as the "gold standard" for the treatment of UPJ obstruction, but due to the surgical The incision is long, the trauma is large, the patient stays in bed for a long time after the operation, the recovery is slow, and the impact on the labor force is also great. In recent years, UPJO surgical methods have developed in the direction of minimally invasive surgery, such as endoscopic balloon dilatation, laser intrapyeloplasty, percutaneous nephroscopic pyeloplasty, and transcystoscopic retrograde pyeloplasty. These are the future development directions of UPJO treatment. Whether it is open surgery or minimally invasive intracavitary surgery, the ultimate goal is to improve kidney function and relieve symptoms.