Objective To evaluate the feasibility and safety of PT Scope(short for intelligent pressure and temperature controlled flexible ureteroscopy)combined with Thulium laser in the intracavitary treatment of upper urinary tract stones.Methods A retrospective analysis was conducted on the clinical data of 13 patients with upper urinary tract stones who were treated with PT Scope combined with Thulium laser lithotripsy in Sun Yat-Sen Memorial Hospital from February to April 2024.There were 7 males and 6 females.The patients had a mean age of(46±10)years old,with an accumulated stone diameter of(25.8±13.3)mm.There were 7 cases of lower calyx stones(53.8%),and 3 cases of concomitant ureteral stones(23.1%).Four patients(30.8%)had positive preoperative urine cultures,and six patients(46.2%)had leukocyte counts greater than 100 cells/μl in their urine tests.The Thulium laser power was set at 45 W(1.5 J at 30 Hz,0.3 J at 150 Hz).The renal pelvic pressure threshold was set at 30 mmHg(1 mmHg=0.133 kPa),and the temperature threshold at 43 ℃.Postoperatively,double J stents were placed for 2 to 4 weeks.Results All 13 patients successfully completed the surgery.The median operative time was 30(25,90)minutes.The intraoperative average renal pelvic pressure in these 13 patients ranged from 8 mmHg to 24 mmHg,and the average renal pelvic temperature ranged from 25 ℃ to 34 ℃.Postoperatively,1 patient experienced a fever(38.0 ℃)and 2 patients required analgesic treatment due to postoperative pain.There were no other intraoperative or postoperative complications.The median postoperative hospital stay was(1.5±0.8)days.The stone-free rate of 1 month was 84.6%(11/13).Conclusions PT Scope combined with Thulium laser could effectively control renal pelvic pressure and temperature,achieve a high stone-free rate,and have a low complication rate.It is a safe and effective treatment for upper urinary tract stones.