Comparative Study Between One-Shot Dilatation Versus Serial Dilatation Techniques for Access in Percutaneous Nephrolithotomy in Adult Patients

Inclusion Criteria: * Patients aged between 18 and 70 years. * Patients with renal stones which their size in maximum diameter is more than 2cm and indicated for percutaneous nephrolithotomy. * Patients clinically fit for surgery. * Patients with normal anatomy of urinary tract. * Patients able to understand the procedure and accept to sign the informed consent. Exclusion Criteria: * Patients aged below 18 or above 70 years. * Patients with renal stones which their size in maximum diameter is less than 2cm or contraindicated for endoscopic management. * Patients with urinary tract infection, abnormal coagulopathy state or clinically unfit for surgery. * Patients with nephrostomy tube in situ. * Patients with more than single access tract. * Patients undergoing simultaneous bilateral stone procedures. * Patients with urinary tract abnormalities or history of renal transplantation. * Renal insufficiency with serum creatinine above 3.0mg/dL * Patients unable to understand the procedure or refuse to sign the informed consent.