Calculus of kidney
Conditions
Interventions
This is a two-arm prospective randomized clinical trial. One hundred adult patients with kidney stones who are candidates for retrograde intrarenal surgery (RIRS) will be included. Patients will be ra
the radiologist responsible for the assessment of computed tomography (CT) scans will be blinded to group assignment. In both groups, RIRS will be performed under general anesthesia. The procedure wil
Sponsors
Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFM/USP)
Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFM/USP)
Eligibility
Age
18 Years to No maximum
Inclusion criteria
Inclusion criteria: Patients aged 18 years or older; both sexes; renal calculi with volume between 1600 and 4000 mm³; candidates for lithotripsy by retrograde ureterorenolithotripsy; provision of written informed consent
Exclusion criteria
Exclusion criteria: Impossibility of performing retrograde ureteroscopy (e.g., prior urinary tract reconstruction); inability to introduce a ureteral access sheath; contraindications to surgery, such as untreated urinary tract infection; concomitant ureteral stone; uncontrolled comorbidities; refusal to provide informed consent
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| It is expected to find higher ablation efficiency (mm³/J) in patients undergoing endoscopic ureterorenolithotripsy (RIRS – Retrograde Intrarenal Surgery) with FANS using the p-Tm:YAG laser in the “Flex long pulse” setting with 2 J and 10 Hz (power of 20 W) compared with the “Flex long pulse” setting with 0.4 J and 50 Hz (power of 20 W). Ablation efficiency will be assessed by calculating the ratio between the volume of stone ablated and the total energy delivered by the laser, using the initial and residual renal stone volumes measured in cubic millimeters (mm³) on non-contrast abdominal and pelvic computed tomography scans performed preoperatively and at 8 weeks postoperatively, with three-dimensional reconstruction and volumetric analysis in the 3DSlicer software. Total energy (J) will be obtained directly from the laser device records at the end of the procedure. The mean ablation efficiency (mm³/J) will be calculated for each group and the difference between the two configurations will be compared | — |
Secondary
| Measure | Time frame |
|---|---|
| It is expected to find a difference in total laser activation time between the two evaluated p-Tm:YAG configurations in patients undergoing retrograde intrarenal surgery (RIRS) with FANS. Total laser time will be assessed using the automatic records from the laser device at the end of the procedure, measured in seconds. The mean laser activation time will be calculated for each group, and the difference between the “Flex long pulse” 2 J × 10 Hz (20 W) and “Flex long pulse” 0.4 J × 50 Hz (20 W) configurations will be compared;It is expected to find a difference in ureteroscopy time between the two laser configurations evaluated. Ureteroscopy time will be assessed using the operative record, defined as the interval between the introduction of the flexible and navigable ureteral access sheath with aspiration (FANS) and its removal at the end of the procedure, measured in minutes. The mean ureteroscopy time will be calculated for each group, and the difference between the two configurations will be compared;It is expected to find a difference in the stone-free rate between the two laser configurations. The stone-free status will be assessed by non-contrast abdominal and pelvic computed tomography performed 8 weeks postoperatively, evaluated by a radiologist blinded to the treatment group, considering “stone-free” as the absence of residual fragments with a diameter = 2 mm. The proportion (%) of stone-free patients will be calculated for each group, and the difference between the two configurations will be compared;It is expected to find a difference in the rate of patients with complete absence of residual fragments (“zero fragments”) between the two configurations evaluated. The presence of “zero fragments” will be assessed by non-contrast abdominal and pelvic computed tomography performed 8 weeks postoperatively, defining “zero fragments” as the absence of any visible stone fragment. The proportion (%) of patients with zero fragments will be calculated for each group, | — |
Countries
Brazil
Contacts
Public ContactHenri Morgan
Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFM/USP)
Outcome results
None listed