Efficacy of Intra-Ureteric Aminophylline Installation After Failed Stone Accessibility by Semi-rigid Ureteroscopy. Prospective Trial

Direct semi-rigid ureteroscopy will initially be attempted without endodilatation (KARL STORZ, 43 cm, 6°, 7 Fr.). On failure to advance the semi-rigid ureteroscope through the ureter, intra-ureteric instillation of 20 ml of aminophylline (250 mg/10 mL) through ureteric stent and another trial to pass the same scope will be done after 10 minutes of intra-ureteral aminophylline instillation.