Regarding to the distribution of nephrostomy tube (NT) size usage by country. There was a clear distinction between countries that used solely the small bore (SB) NT (Chile and Australia) and those that used solely the large bore (LB) NT (Czech Republic and Japan). There is also a trend toward SB NT in North America (~75% in USA and Canada) and toward LB NT in South America (~80% in Argentina and Mexico). In Europe the trend is equal (~50% in Germany, France, Greece and UK). Based on previous data and in view of conflicting data about postoperative complication including extravasation, bleeding and hemoglobin change and pain between previous studies, we will conduct this randomised trial comparing SB and LB NT following PNL.

Our aim to evaluate the safety of small versus large bore NT reporting complications using the Clavien-Dindo system with categorisation of PNL-specific complications

Inclusion Criteria:

1. Staghorn calculi
2. Renal pelvis stones =>2 cm
3. Lower pole stones= >1.5 cm
4. upper ureteral calculi =>1.5 cm
5. SWL-resistant stones

Exclusion Criteria:

1. Age <18 years or Pregnancy
2. Tubeless PNL
3. Need for 3 percutaneous tracts intraoperative
4. Morbid obesity (BMI >40)
5. Refuse to complete study requirements
6. Tumour in the presumptive access tract area or Potential malignant kidney tumour