Please select the eligibility criteria that correspond to the clinical trial below.
Title: N/A
Brief Summary: Purpose: to investigate the postoperative outcomes of Retrograde intrarenal surgery versus percutaneous nephrolithotomy in 2 to 4 cm kidney stones.


Options:
A: Inclusion Criteria:

1. 10-20mm lower pole renal stone measured by KUB or CT;
2. Age between 18-60 years, no gender limitation;
3. Participators can understand the research and sign the consent form without mental illness nor language disorder;
4. Low pole renal stone left after lithotripsy;
5. Lower pole infundibulopelvic angle which measured by IVP or CTU will less than 30 degree;
6. Asymptomatic patients with positive urine white blood cells and negative preoperative urine culture should be treated with antibiotics for 3days before operation;
7. Patients with symptoms of urinary infections, positive urine withe blood cells and positive preoperative urine culture should be treated with suitable antibiotics based on the culture sensitivity result for at least 7days before operation.

Exclusion Criteria:

1. Transplant kidney stone;
2. Renal malformations, such as UPJO, medullary sponge kidney, polycystic kidney, horseshoe kidney, etc.;
3. Combine other part of urinary stones need to be handle at the same procedure, for example ureteral stone, renal pelvic stone, middle or upper pole renal stone;
4. Hematological Disease or Coagulation disorders;
5. Withdraw anticoagulant medicine less than two weeks;
6. Fever or urinary infections without treatment according to the inclusion criteria;
7. Sevier renal dysfunction(endogenous creatinine clearance rate≤50ml/min)
8. Middle or severe hydronephrosis(dilatation of the renal pelvis ≥20mm by ultrasound);
9. Women in menstrual period or pregnancy;
10. Patients have severe disease, such as heart disease, lung dysfunction, and multiple organ failure that cannot tolerate anesthesia or operation.
B: Inclusion Criteria:

* The patients who have 2 to 4 cm kidney stones
* ASA score within 1 to 3

Exclusion Criteria:

* Previous surgical treatment including SWL
* Congenital abnormalities
C: Inclusion Criteria:

* renal stone measuring 6 to 20 mm
* signing informed consent
* WHO performance status 0-2

Exclusion Criteria:

* Other stone \>5 mm
* concomitant ureteral stones
* BMI \> 35
* severe coagulopathy
* impossibility to sign informed consent
* pregnancy
* age \< 18 years old or \> 85
D: Inclusion Criteria:

1. Patients aged \> 18 years old
2. Patients with renal stone or stones of 10-30 mm in maximal diameter measured in computed tomography scan.
3. Decision of the patient to receive surgical treatment
4. Ability to understand and provide a written informed consent to participate in the study.

Exclusion Criteria:

1. Solitary kidney (functional or organic)
2. Ureteral stone in the same system causing obstruction
3. Malignant tumor in the treated kidney
4. Stone in diverticulum
5. Diabetes or coronary heart disease.
6. History of surgery in the treated kidney
7. Recent intake of drugs that affect renal function or intravenous contrast agent
8. Concomitant urinary infection
9. Congenital anomalies of the urinary tract
10. Patients of whom incomplete clinical data or incomplete samples are available

Answer: B