Disposable 7.5Fr Electronic Flexible Ureteroscope Combined 10Fr Ureteral Access Sheath for Treatment of Renal Stone <2cm

Inclusion Criteria: 1. Patients with kidney stones less than 2cm who choose to perform "Flexible ureteroscopic holmium laser lithotripsy"; 2. Over 18 years old, male or female; 3. No hydronephrosis or mild to moderate hydronephrosis (collection system separation is less than 2cm); 4. The subject has no mental illness or language dysfunction, can understand the situation of this study and has signed an informed consent form, and is estimated to be able to cooperate with the completion of the entire study; 5. No urinary tract infection or no clinical manifestations of urinary tract infection; 6. Patients with urinary tract infection, negative urine culture, and no fever need to undergo antibiotic treatment for more than 3 days; urinary routine examination suggests urinary tract infection, positive urine culture, and patients without fever need to undergo antibiotic treatment for more than 7 days, till the urine culture turns negative. Exclusion Criteria: 1. Patients with a previous history of ureteral stenosis or who have undergone open, laparoscopic ureteral, nephrectomy and lithotripsy; 2. Fever or urinary tract infection is not treated according to the inclusion criteira; 3. Pregnant women and women's menstrual periods; 4. Cannot tolerate anaesthesia or surgery due to serious systemic diseases, heart disease, lung insufficiency and failure of important organs; 5. Anatomical malformations such as polycystic kidneys, horseshoe kidneys, and ectopic kidneys; 6. Patients with high suspicion of ureteral stenosis or diseases that are considered unsuitable to participate in this clinical study; 7. Patients indwelling double J stent preoperatively; 8. Patients who need bilateral upper urinary tract surgery at the same time.