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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Safety And Efficacy Of Ultra-Mini Percutaneous Nephrolithotomy In Comparison With Standard Percutaneous Nephrolithotomy For Management Of Renal Calyceal Calculi 1 Cm To 2 Cm In Size. Comparative Randomized Prospective Study

Conditions
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Stone, Kidney

Intervention / Treatment
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* Procedure: percutaneous nephrolithotomy
* Procedure: ultra-mini percutaneous nephrolithotomy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: adult patient aged over 18 with renal stone between 1 and 2 cm Exclusion Criteria: patient with a single kidney. Renal stones larger than 2 cm or less than 1 cm. Patients with uncontrolled co-morbidities (hypertension, diabetes mellitus, cardiac disease, chest disease). Patients with active urinary tract infection. Patients with other anatomic renal abnormalities (congenital renal malformations such as horseshoe kidney, polycystic kidney disease, etc.). and Patients with severe skeletal deformity. Pregnant women. Patients with Uncorrectable bleeding disorder. Patients who underwent renal transplantation or urinary diversion

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: To compare the difference between the two procedures regarding stone-free rates, operative time, hospital stay, procedures cost, and operative complications including blood loss, the need for blood transfusion, and extravasation or urine leakage
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: percutaneous nephrolithotomy<br>Patients are positioned in the lithotomy position and a 6F ureteral catheter is placed and the bladder is drained with a 16F urethral Foley catheter. After ureteral catheterization, patients are placed in the prone position, and percutaneous access of the desired calyx is achieved under fluoroscopic guidance with the use of an 18-gauge needle and a guidewire passage. Tract dilation is accomplished by using Amplatz dilators up to 30F. Pneumatic lithotripter is used for fragmentation and stone removal is accomplished with retrieval graspers through a rigid 22F nephroscope. An 18-24 F nephrostomy tube is placed at the end of the operation. | Procedure: percutaneous nephrolithotomy<br>* percutaneous access of the desired calyx is achieved under fluoroscopic guidance with the use of an 18-gauge needle and a guidewire passage. Tract dilation is accomplished by using Amplatz dilators up to 30F.<br>|
| Experimental: ultra-mini percutaneous nephrolithotomy<br>Patients are positioned in the lithotomy position and a 6 F ureteral catheter is placed and the bladder is drained with a 16F urethral Foley catheter. After ureteral catheterization, patients are placed in the prone position, and percutaneous access of the desired calyx is achieved under fluoroscopic guidance with the use of an 18-gauge needle and a guidewire passage. Tract dilation is accomplished by using Amplatz dilators up to 12-14 F fascial dilator was used to dilate the nephrostomy tract to pass the 13 F semi-rigid plastic sheath. Then, a 9.5-F, rigid ureteroscope (KARL STORZ Medical Instruments) was introduced to the sheath. The renal stones were broken into pieces using holmium laser lithotripsy. Finally, the ureteroscope and sheath were removed and the tract site was packed for 2-3 min. then placement of double J stent will be done according to the decision of the operating surgeon for 3 to 4 weeks. | Procedure: ultra-mini percutaneous nephrolithotomy<br>* percutaneous access of the desired calyx is achieved under fluoroscopic guidance with the use of an 18-gauge needle and a guidewire passage. Tract dilation is accomplished by using Amplatz dilators up to 12-14 F fascial dilator was used to dilate the nephrostomy tract to pass the 13 F semi-rigid plastic sheath.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| stone free rate of patients with renal stones by non contrast CT scan | efficacy of the procedure to clear renal stones completely in single session, non contrast CT will evaluate the stone burden and compare it to the preoperative measurement | first day postoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| operative time of both procedures | time of each procedure in minutes from the lithotomy positioning till completion of the procedure | intraoperative finding | 
| hospital stay of the patient | duration till patient is discharged in days | 1 to 3 days postoperative | 
| hemoglobin drop of the patients | decrease in the hemoglobin level in comparison to the preoperative results | first day postoperative | 
| postoperative urine leakage from the surgical wound | urine leakage from the nephrostomy site if it present or not as document during surgical dressing by the attending physician | first day postoperative | 
| cost analysis of both procedure | cost of each procedure including operative cost and postoperative stay in Egyptian Pound | 3 days postoperative |