The investigator will compare between holmium laser setting during miniPCNL for renal stones as regard safety & efficacy

The first 80 consecutive Patients presented to the department of urology, Mansoura Urology and Nephrology Center and fulfilling the inclusion criteria will be included in the present study.

Preoperatively, all patients will be thoroughly evaluated by medical history and physical examination including body mass index (BMI), laboratory assessment (including urine analysis/culture, serum biochemistry, CBC, bleeding profile).

Radiological assessment will include plain X-ray Kidney-Ureter-Bladder (KUB), abdominal ultrasound and non-contrast computed tomography (NCCT).

NCCT images will be obtained from above the kidneys through the bladder base. For each renal stone, location, largest diameter, burden and density will be assessed.

Culture based antibiotic is given. Under spinal anaesthesia, the patient is initially placed in lithotomy position for retrograde ureteral catheter placement, then repositioned to prone or modified supine position for percutaneous access.

Under fluoroscopic guidance, an 18G Chiba needle is used to access a posterior calyx or the appropriate target calyx). Contrast confirms the collecting system entry.

Dilation is performed, typically up to 14-20 Fr. A mini-nephroscope (15 Fr) is inserted through an appropriate sheath. Irrigation is maintained using gravity or low-pressure systems.

Holmium: YAG laser is used for lithotripsy. high pulse power will be capped at 40 W, while low pulse power settings will remain between 10-20 W. Fragments are evacuated via vacuum cleaner effect or basket through the sheath.

Depending on intraoperative findings, a nephrostomy tube and/or double-J stent may be placed. Tubeless approach may be considered.

Inclusion Criteria:

• Age ≥ 18 years
• Renal Stones < 20 mm indicated for intervention (pain, infection, obstructing stone causing hydronephrosis or parenchymal affection)
• Informed consent obtained

Exclusion Criteria:

• Active urinary tract infection
• Bleeding diathesis
• Pregnancy
• Anatomical anomalies impeding access e.g. ectopic malrotated kidneys, crossed fused kidneys...etc.)