Ureteroscopic Laser Modality on Total Lasing Time and Total Energy in Patients With Large, Dense Renal Calculi

Inclusion Criteria: * Adults between the ages of 18-80. * Any gender, race or ethnicity may be included- these factors play a small, if any role on renal calculi formation and ability to withstand procedure. * Must be suitable for a flexible ureteroscopy as determined by the MD * Large renal calculi burden of single or multiple stones with the sum of its longest diameters between 10-20 mm * An average stone density of at least 1000 Hounsfield units. Exclusion Criteria: * Those with a stone burden less than 10mm or more than 20mm. * Those with an average stone density below 1000 Hounsfield units. * Patients who are dependent on mandatory anticoagulation therapies and cannot stop for surgery * Patients that cannot undergo ureteral access sheath placement * Patients with abnormal anatomy such as horseshoe kidney * Patients with a history of: * Ipsilateral upper urinary tract reconstructive procedures on the side of the renal calculi * Ipsilateral ureteral strictures * Prior radiotherapy of the abdomen or pelvis * Neurogenic bladder * Spinal cord injuries * Those who are pregnant * Currently being treated for infection or cancer