To explore the clinical efficacy of high-pressure balloon dilation for benign ureteral multinodular stenosis, we summarized the clinical data of 15 patients with benign ureteral multinodular stenosis admitted to our department from October 2008 to August 2009, which are reported below. Subjects and methods 1. Clinical data 15 patients (17 sides) in this group; 11 males, 4 females; age 20-65 years, mean age 40 years; 13 cases of unilateral multisegmental stenosis, 2 cases of bilateral multisegmental stenosis; 7 cases of postoperative scar stenosis; 5 cases of congenital stenosis; 3 cases of inflammatory stenosis; 13 sides by retrograde method of transurethral intubation; 4 sides by paracentesis method of percutaneous renal puncture. (1) Preoperative preparation: preoperative blood and urine routine, liver and kidney function, electrolytes, bleeding and coagulation function, hepatitis B and half, HIV antibody, electrocardiogram, chest X-ray, urological ultrasound, ECT nephrographic fractional renal function test, magnetic resonance water imaging; correction of bleeding and coagulation mechanism disorders; preoperative antibiotics to prevent infection. (2) Instrument preparation: cystoscope; X-ray fluoroscopy equipment (if preparing to perform percutaneous renal puncture by paracentesis also need to prepare ultrasound positioning); Bard balloon expansion kit, including: tiger tail catheter, ultra-slip guidewire, high-pressure expansion balloon, pressure gauge, double lumen sheath, double J tube. (3) Surgical procedure: insert the tiger tail catheter into the renal pelvis, inject the contrast agent and visualize the entire pelvic ureter, clarify the stenosis site, insert the ultra-slip guidewire along the tiger tail catheter into the renal pelvis, insert the high-pressure dilating balloon upward along the ultra-slip guidewire, locate the balloon position under fluoroscopy, dilate the stenotic ureter segment by segment until the wasp waist disappears, maintain the dilated state for 5 min, remove the balloon and cystoscope after the end of dilatation, and insert the ultra-slip guidewire upward If there is difficulty in retrograde intubation under cystoscopy, cystoscopy can be performed under B-ultrasound positioning, and the superslip guidewire can be inserted from the renal pelvis to the bladder along the puncture channel under fluoroscopy, and then the balloon can be dilated along the guidewire. The double D-J tubes were left in place for 3-5 months after the operation, during which the urinary routine, abdominal plain film and urological ultrasound were reviewed monthly. 3.Follow-up and efficacy evaluation Renal function, urinary ultrasound and ECT nephrogram score renal function check were repeated every 3 months after extubation. Cured: clinical symptoms disappeared, ultrasound or retrograde imaging showed significant improvement of pelvic fluid, and renal chart showed significant improvement of kidney function; Effective: symptoms disappeared or improved significantly, ultrasound or retrograde imaging showed improvement of pelvic fluid or no further aggravation, renal chart showed improvement of kidney function or no further deterioration; Ineffective: symptoms did not improve or reappeared after disappearance, ultrasound or retrograde imaging showed aggravation of pelvic fluid, and renal chart showed continued deterioration of kidney function. The nephrogram showed that the renal function continued to deteriorate. Results: All 15 cases (17 sides) were operated successfully without postoperative complications such as bleeding and urinary extravasation. After surgery, all 15 cases were followed up for 3-10 months, with 9 cured, 5 effective and 3 ineffective sides, with a total effective rate of 82.4%. Discussion The causes of benign ureteral multisegmental stenosis include stones, infection, postoperative scar contraction adhesions, congenital stenosis due to ureteral smooth muscle dysplasia, ectopic vascular compression, retroperitoneal fibrosis, and medically induced stenosis. Most patients have hydronephrosis and renal function impairment. In the past, most patients were treated by open surgery, but open surgery is very traumatic, slow to recover, and has many complications. If both upper and lower ureteral stenosis occur, it is difficult to choose the surgical incision, and a certain percentage of restenosis may still occur after surgery. Therefore, people have been exploring treatment methods with less trauma and higher success rate. With the development of endoluminal urology technology and equipment, minimally invasive treatment methods such as balloon dilation, ureteroscopic cold knife incision, and holmium laser endotomy have emerged in recent years. The mechanism of balloon catheter dilation for ureteral stenosis is to break the fibrous scar at the stenosis, increase the internal diameter of the stenotic segment, and allow ureteral recanalization. The action of the balloon on the ureteral wall is static, with radial expansion and uniform force on the wall, which is characterized by less trauma, easier operation, fewer complications and repeatable treatment. Some foreign scholars reviewed the efficacy of surgical open surgery and balloon dilation for ureteral stenosis and concluded that dilation should be preferred as long as the guidewire and catheter can pass through the stenotic segment. It is superior to open surgical treatment in terms of surgical success rate, complications and efficacy. However, the restenosis rate after common balloon dilation is still as high as 30% or more, and the reasons for this are related to incomplete dilation and poor postoperative drainage. The maximum pressure of ordinary balloon dilation is generally lower than 15 atmospheres, while many benign ureteral stenoses, especially those caused by postoperative scar contraction, require a dilation pressure of 20 atmospheres to achieve complete dilation. High-pressure balloon dilation pressure can reach a maximum of 30 atmospheres, which is a good solution to the problems caused by low pressure of ordinary balloon dilation. After dilatation, double “J” stent tubes are usually placed. The following functions are played by the placement of double “J” tubes: 1) the bent and angled ureter can be straightened to make the stenosis wider; 2) the local tissue is edematous and the lumen is narrowed after dilatation. The double “J” tube can drain the pelvic urine, protect the kidney function and promote the recovery of kidney function; 3) the double “J” tube plays a supporting role for the narrowed ureter. If the time is too short, the fibrous scar formed in the stenosed ureter after balloon expansion is unstable and prone to restenosis, we routinely keep double D-J tubes for 3-5 months after surgery. After the placement of the internal stent, the urine flow is mainly through the periampullary area of the internal stent, but not the lumen of the internal stent. However, in the case of ureteral stenosis, due to the fibrosis of the ureteral wall at the stenosis site, the ureter cannot be dilated, and in this case, the space between the endoprosthesis and the ureter shrinks or disappears, and the endoprosthesis placed at this time may become an obstruction, leading to poor drainage and extravasation of urine and infection, which will be the cause of restenosis. In contrast, placing two double “J” tubes in parallel not only dilates the ureter and reduces ureteral distortion, but also allows urine to flow down through the gap between the two stent tubes, playing a good drainage role; at the same time, the two double “J” tubes can also play a good support and expansion role, reducing the occurrence of restenosis. At the same time, the two double “J” tubes can play a good supporting and dilating role to reduce the occurrence of restenosis.