Background: The exit strategy after ureteroscopy for stone treatment remains a topic for discussion. Current EAU guidelines on urolithiasis state that postoperative stenting is indicated in patients at increased risk of postoperative complications. Stenting is not considered necessary in all other cases, and after uncomplicated procedures.

Objective: To analyse the postoperative ureteral stenting strategy in clinical practice looking at the indication, type of stents used and the duration of stenting after ureteroscopy for stone treatment. Furthermore, the investigators will examine in what setting the stents are being removed postoperatively.

Study design: This study is a prospective, observational, international, multicentre registry study executed by uCARE.

Study population: All patients >18 years with a ureter or renal stone who are planned for ureteroscopic treatment by semi-rigid and/or flexible ureteroscopy are eligible for this study.

BACKGROUND AND RATIONALE

The majority of patients with stones receive an indication for its active removal by ureteroscopy. In the last two decades, endourological treatment techniques have evolved with several technological advances through miniaturisation of ureteroscopes, digital improvements, and optical imaging enhancement techniques leading to a better image quality, and the development of different disposables such as single-use digital ureteroscopes. This advancement has led to an increased number of indications for ureteroscopic treatment. Aside from this, there are no specific contraindications for ureteroscopic treatment, apart from general problems such as being unfit for anaesthesia or the presence of urinary tract infections, according to the EAU guidelines.

The indications for active stone removal of ureteral stones include persistent pain or obstruction, renal insufficiency, and in cases when spontaneous passage is less likely. The indications for active removal of renal stones include stone growth, stone formation in patients who are at high risk for stone formation, symptomatic patients, infection, obstruction, stones larger than 15 mm and the comorbidity profile, social situation and preference of the patient.

The procedure can be performed using semi-rigid instruments, mainly for ureter stones, and/or by flexible ureteroscopes, for complete inspection and treatment of the upper tract.

The exit strategy after stone treatment varies depending on patient characteristics and comorbidity, residual stone load, per-operative details and complications, and surgeons' preference. Stent placement is recommended by the EAU guidelines in case of increased postoperative complications; in cases of residual fragments, bleeding, perforation, pregnancy or urinary tract infections; as well as in all doubtful cases to avoid stressful emergencies.

Postoperative stenting increases postoperative morbidity and urologists should carefully balance the pros and cons of postoperative stenting in each individual case. The ideal stent duration is not known. Ureteral stents are usually removed 1-day postoperatively and most urologists will remove double Js 1-2 weeks postoperatively.

It remains a matter of debate whether to stent a patient postoperatively after a ureteroscopic procedure despite the EAU guidelines statement that routine stenting after an uncomplicated procedure with complete stone removal is not necessary.

STUDY OBJECTIVES

The aim of this registry is to review current clinical practice on postoperative ureteral stenting after ureteroscopy for stone treatment. The investigators will explore the answers to the following questions: What are the indications, predictors and outcomes for stent placement? What types of stents are used and what is the duration for stent placement? Hence, the investigators will assess in what setting the stents are being removed, looking at instrumentation, anaesthetics, and location.

Inclusion Criteria:

• Patient >18 years old
• Patient is a candidate for ureteroscopic treatment of a ureter or renal stone by semi-rigid and/or flexible ureteroscopy

Exclusion Criteria:

• Patient <18 years old

All patients >18 years old with a ureter or renal stone that are planned for ureteroscopic treatment are eligible for this registry.