To investigate the feasibility and safety of a treatment system for stentless discharge after flexible ureteroscopic lithotripsy assisted by flexible negative pressure sheath.

The clinical data of 72 patients with upper urinary calculi admitted to the Second Hospital of Tianjin Medical University from November 2022 to February 2023 were retrospectively analyzed. All patients achieved stentless discharge after flexible ureteroscopic lithotripsy assisted by flexible negative pressure sheath. There were 50 males and 22 females. The average age was (54.7±12.1) years. Preoperative urine culture was positive in 14 cases, negative in 3 cases (4.2%)with nitrite positive, and 11 cases were negative for urine culture and nitrites but positive of white blood cells (+ + + ). There were 29 cases of renal calculi, 33 cases of upper ureteral calculi, and 10 cases of upper ureteral calculi combined with renal calculi.The mean stone diameter was 17.0(14.0, 24.0)mm. CT value was (1 049.3±258.6)HU. Twenty-four patients carried ureteral stents before operation. A total of 42 cases used ureteral sheaths with diameters of F11/13, and 30 cases used sheaths with diameters of F12/14.During the operation, an infusion pump was used to provide sufficient irrigation pressure. The negative pressure suction was attached to the distal end of the sheath. The flexible head of the sheath was guided to the target renal calyx, to completely aspirate stone fragments. Stone baskets was used in 11 cases during the procedure. The level of ureteral injury was assessed according to the Traxer grading system at the end of the operation. A ureteral stent with extraction string was retained.On the first day postoperatively, CT scanning was performed to evaluate the residual stone fragments. Patients were discharged on postoperative day 2-3 after the removal of the ureteral stent and catheter. Follow-up was conducted for 30 days postoperatively, during which the Ureteral Stent Symptom Questionnaire (USSQ) was used to assess voiding symptoms and pain. Painkiller usage and emergency revisit situations were recorded. CT scans were performed to evaluate the stone-free rate on postoperative day 30.

The average operation time was 30.0 (20.0, 44.5) minutes. A total of 70 cases had no ureteral injuries, and 2 cases had Grade 1 ureteral injuries (minor mucosal damage). Three cases developed fever within 72 hours postoperatively, with no cases of septic shock or fever after stent removal. Eight patients reported waist and abdominal discomfort after discharge and took oral pain medication. Among them, one patient returned to the emergency department for pain treatment. Five patients reported moderate or severe genitourinary symptoms (including voiding frequency, nocturia, urgency/incontinence, dysuria, hematuria, and incomplete emptying) based on subjective evaluation. All patients could work and recovered a normal daily life after discharge and there was no readmission or additional surgical procedures. There were 61 patients achieved immediate stone-free status on the first day after surgery, and 66 patients achieved stone-free status during follow-up at 30 days postoperatively.

Stentless discharge after flexible ureteroscopic lithotripsy assisted by flexible negative pressure sheath is safe and feasible.

Urinarycalculi; Flexible ureteroscopic lithotripsy; Ureteral stent; Stentless