Intra-ureteric Aminophylline Instillation on Flexible Ureteroscopy Procedure

in this study we are going to evaluate the efficacy of intra-ureteric aminophylline instillation in facilitating ureteric access sheath placement prior to flexible ureteroscopy in reducing ureteric injury rates.

Urolithiasis (kidney and ureteral stones) is a common urologic condition with increasing prevalence. Flexible ureteroscopy (FURS) is a minimally invasive technique widely used for upper ureteric and renal stones. Aminophylline, a methylxanthine derivative, has been shown to relax smooth muscles and was previously used intravesically to facilitate rigid ureteroscopy with reduced complications. This study aims to assess whether intra-ureteric aminophylline instillation improves the ease of ureteral access sheath (UAS) placement during FURS and reduces ureteric injuries. patients will be divided into 3 groups: 1. Group A (Aminophylline Group): Intra-ureteric instillation of aminophylline 2. Group B (Ureteral Dilator Group): Traditional ureteral dilators 3. Group C (Combination Group): Aminophylline instillation + Ureteral dilators follow up of the patients will be through the success rate or failure of ureteric access sheath placement, operative time, bleeding, intra/postoperative complications and stone clearance (3-week follow-up with CT scan)