Bendable Suction Ureteral Access Sheath Versus Conventional Ureteral Access Sheath in Management of Renal Stones Using Flexible Ureteroscopy

Inclusion Criteria: * Diagnosis: Radiologically confirmed renal stones (e.g., CT, ultrasound, or X-ray). * Stone size within a specific range (e.g., 5-20 mm). * Indication for Treatment: patients indicated for flexible ureteroscopy due to renal stones. * Anatomical Suitability: normal or mildly altered renal anatomy that allows safe use of the access sheath. * Willingness to participate and provide written informed consent. Exclusion Criteria: * \- Medical Conditions: Active urinary tract infection (UTI) or sepsis. Coagulopathy or inability to discontinue anticoagulation therapy. Significant comorbidities (e.g., severe cardiopulmonary disease). Pregnancy: Pregnant or breastfeeding individuals. * Anatomical or Surgical Factors: Severe ureteral stricture or obstruction preventing sheath placement. Congenital abnormalities affecting the urinary tract. - Stone Factors: Stones larger than the sheath's operational limit (e.g., \>20 mm). Multiple stones in different calyces that cannot be accessed in one session. \- Previous Treatment: Recent (\<6 weeks) or repeated interventions for the same stones (e.g., prior lithotripsy or ureteroscopy).