Ultra-Mini Versus Standard Percutaneous Nephrolithotomy For Management Of Renal Calculi. A Randomized Controlled Trial.

Renal stones are one of the most common urological problems and there are multiple methods for their management such as percutaneous nephrolithotomy, mini and ultra-mini percutaneous nephrolithotomy, flexible ureteroscopy and laser lithotripsy, and extracorporeal shock wave lithotripsy. percutaneous nephrolithotomy is the treatment of choice for the management of renal calculi, in spite of the increasing stone clearance rate, the complication rate of this procedure is relatively higher.

Nephrolithiasis is a major worldwide source of morbidity, constituting a common urological disease affecting 10-15% of the world population. Consistent technical advancements provide surgeons and patients with several options for the treatment of renal calculi, including extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), and conventional open surgery.

Percutaneous nephrolithotomy (PCNL) is generally considered a gold standard in renal stones particularly larger than 2cm or lower calyceal larger than 1cm offering high stone-free rates after the first treatment as compared to the other minimal invasive lithotripsy techniques.

Percutaneous nephrolithotripsy (PCNL)is a procedure to remove kidney stones from the kidney through a small incision in the skin and it was initially described in the literature by Fernström and Johansson in 1976. Traditionally, the prone position was considered the only position to obtain renal access for PCNL. In 1987, Valdivia Urìa presented the supine PCNL.

PCNL is also recommended in the case of smaller stones in patients with contraindications for shockwave lithotripsy (SWL), such as shockwave resistant stones and anatomical malformations, or when a patient elects PCNL as a procedure of higher efficacy. However, serious complications although rare should be expected following this percutaneous procedure as, Perioperative bleeding, urine leakage from nephrocutaneous tract, pelvicalyceal system injury, pain.( Kyriazis et al 2015) colon injury, hydrothorax, pneumothorax, prolonged leak, sepsis, ureteral stone, vascular injury and acute loss of kidney, all are individually confronted complications after PCNL.

PCNL techniques include: standard PCNL (S-PCNL), mini-PCNL (also called miniperc), ultra-mini-PCNL (UM-PCNL) and the recently introduced micro-PCNL. One of the most important differences between the various PCNL techniques is the size of renal access, which contributes to the broad spectrum of complications and outcomes.

Eligibility Criteria:
Inclusion Criteria:

* adult patient aged over 18 with renal stone between 1 and 2 cm

Exclusion Criteria:

1. patient with a single kidney.
2. Renal stones larger than 2 cm or less than 1 cm.
3. Patients with uncontrolled co-morbidities (hypertension, diabetes mellitus, cardiac disease, chest disease).
4. Patients with active urinary tract infection.
5. Patients with other anatomic renal abnormalities (congenital renal malformations such as horseshoe kidney, polycystic kidney disease, etc.). and Patients with severe skeletal deformity.
6. Pregnant women.
7. Patients with Uncorrectable bleeding disorder.
8. Patients who underwent renal transplantation or urinary diversion