Effect of Preoperative Alpha-blockers on Successful Insertion Ureteral Access Sheath and Reduce Ureteral Injury in Non-prestented Patients During RIRS. Assessment of Factors for Successful Ureteral Access Sheath Insertion.

Study Title:

Effect of Preoperative Tamsulosin and Silodosin on Successful Insertion Ureteral Access Sheath and Reduce Ureteral Injury in Non-Prestented Patients During Retrograde Intrarenal Surgery (RIRS). Assessment of factors for successful ureteral access sheath insertion. Randomized clinical trial.

Study Design:

Prospective, randomized, open-label, controlled trial with four parallel arms. Conducted from July 2021 to June 2024.

Study Center:

Department of Urology, St. Luke's Clinical Hospital, St. Petersburg, Russia

Study Population:

140 patients, divided into four equal groups of 35 people each: Group I (Tamsulosin): Non-prestented patients receiving 0.4 mg of Tamsulosin daily for 7 days before RIRS.

Group II (Silodosin): Non-prestented patients receiving 8 mg of Silodosin daily for 7 days before RIRS.

Group III: Prestented patients. Group IV: Control group (non-prestented patients)

Interventions:

All patients received antibiotic prophylaxis with third-generation cephalosporins 30 minutes before surgery.

RIRS was performed using disposable flexible ureteroscopes. The UAS diameter was 11/13 Fr. Thulium fiber laser was used for lithotripsy. Stone fragmentation was performed in dusting and fragmentation modes, with a total power not exceeding 20 W and a fiber thickness of 200 µm.

Statistical Analysis:

Data were analyzed using Shapiro-Wilk, Mann-Whitney U, Kruskal-Wallis, and chi-square tests with Bonferroni correction (SPSS v26, JMP Pro 17). Statistical significance was set at p<0.05.

Key Findings:

Comparable baseline characteristics (p>0.05)

Significantly higher UAS success rates:

Tamsulosin: 31 (88.57%)

Silodosin: 32 (91.43%)

Prestented: 33 (94.29%)

Control: 62.86% (p=0.0008)

Preoperative taking Silodosin significantly reduced degree ureteral injury (p=0.0253).

Patients receiving alpha-blockers experienced less postoperative pain compared to the control group (p<0.0001) and less inflammatory changes in blood tests compared to prestented patients (WBC: p=0.0002; CRP: p<0.0001)

Patients with BMI ≥ 25 kg/m² and age ≥ 59 years had a higher success rate of UAS insertion (p<0,0001).

Patients with BMI ≥ 25 kg/m² and age ≥ 59 years have a lower degree of ureteral injury (p<0,0001).

Conclusions:

Preoperative taking of alpha-blockers (Tamsulosin or Silodosin) increases the success of UAS insertion.

Silodosin reduces the degree ureteral injury. Patients taking alpha-blockers less postoperative pain and inflammatory changes in blood tests.

A BMI ≥ 25 kg/m² and age ≥ 59 years increase the success of UAS insertion and reduce degree of ureteral injury

Clinical Implications:

This study provides evidence supporting the use of alpha-blockers, particularly silodosin, for passive ureteral dilation prior to RIRS in non-prestented patients, potentially reducing compications and improving patient outcomes.

Inclusion criteria

• Patients aged 18 years and older
• Kidney stone size: ≤2 cm
• Stone density >1000 Hounsfield units
• Sterile urine culture

Exclusion criteria

• Congenital anomalies of the urinary tract
• Urinary tract infections
• Upper urinary tract obstruction
• Prior reconstructive surgeries on the upper urinary tract