BSUS patients were prospectively enrolled in this study, and non-randomly treated with "balloon dilation +CMUS" and "balloon dilation + tandem DJ stent". Perioperative data of the patients were recorded to compare their efficacy and complications, and the ureteral stent symptom questionnaire was used to compare their impact on patients' quality of life. CMUS and tandem DJ stents were removed after ≥3 months of indwelling. After the removal of stents, the patients' serum creatinine and renal pelvis width were followed up to compare their curative effect on BSUS.

The ureteral stricture is caused by various benign and malignant reasons, and then appears hydronephrosis and progressive decline of renal function. Benign short ureteral stenosis (BSUS) especially refers to ureteral stenosis of no more than 2cm in length caused by benign causes such as impacted ureteral stone or endoscopic lithotomy. Currently, BSUS can be treated with laparoscopic or open ureteroplasty, endoscopic balloon dilation or ureterotomy, ureteral stents insertion, or nephrostomy. Since its introduction, covered metal ureteral stent (CMUS) can be used to treat various types of ureteral stricture, achieving a long-term patency rate of more than 80% for BSUS and even curing some patients. It also has fewer complications than a double-J stent (DJ stent). However, there is still a lack of comparative studies on the therapeutic effect and complications of the two treatment methods, namely CMUS after balloon dilation and tandem DJ stent, for BSUS, especially the evaluation of the curative effect of BSUS. Therefore, BSUS patients were prospectively enrolled in this study, and non-randomly treated with "balloon dilation +CMUS" and "balloon dilation + tandem DJ stent". Perioperative data of the patients were recorded to compare their efficacy and complications, and the ureteral stent symptom questionnaire was used to compare their impact on patients' quality of life. CMUS and tandem DJ stents were removed after ≥3 months of indwelling. After the removal of stents, the patients' serum creatinine and renal pelvis width were followed up to compare their curative effect on BSUS.

Inclusion Criteria:

• BSUS patients from January 2023 to January 2024 in Peking University People's Hospital, no gender limitation, aged from 18 to 80, Benign ureteral stricture with definite reason (ureteropelvic junction obstruction, ischemic ureter stenosis caused by surgical separation, ureter partial excision anastomosis stricture after operation, ureteral stricture caused by ureteral endoscope surgery, ureteral stenosis caused by impacted ureteral calculi, ureteral anastomotic stricture after urinary flow diversion, ureteral anastomotic stricture after kidney transplantation, retroperitoneal fibrosis, ureteral stricture caused by trauma, idiopathic ureteral stricture), patients can tolerate anesthesia and surgery and obtain informed consent.

Exclusion Criteria:

• Patients with hypertonic neurogenic bladder, severe bladder outlet obstruction or bladder capacity less than 50ml, combined with sepsis, incomplete clinical data, failed stent implantation, insufficient indwelling time (< 3 months), postoperative loss of follow-up.