A Novel Technique of Ultra-Mini-Percutaneous Nephrolithotomy: Introduction and an Initial Experience for Treatment of Upper Urinary Calculi Less Than 2 cm

Table 1

Patient demographics and stone characteristics.

Mean ± SD age (yr)	48.2 ± 15.7 (2–79)
No. male/female	23 (63.9%)/13 (36.1%)
Mean ± SD stone area (mm^2)	160.6 ± 82.7 (30–380)
Mean ± SD stone size (mm)	14.9 ± 4.1 mm (6–20)
Left/right side stone	15 (41.7%)/21 (58.3%)
No. positive preoperative urine culture	None
No. medical comorbidity
Hypertension	2 (5.6%)
Diabetes	2 (5.6%)
Renal failure	1 (2.8%)
Spinal disease	1 (2.8%)
Poly renal cyst	1 (2.8%)
Stone locations
Pelvic calculi	5 (14%)
Upper calyceal stone	7 (19.4%)
Middle calyceal stone	8 (22.2%)
Lower calyceal stone	10 (27.8%)
Upper ureteral stone	3 (8.3%)
Multiple calyceal stones	3 (8.3%)
Patients with special situations
Transplanted kidney stone	1 (2.8%)
Diverticular renal stone	2 (5.6%)
Stone with narrow infundibulum	1 (2.8%)
Residual stones after ESWL	6 (16.7%)
Failed RIRS	5 (13.9%)
Residual stones after PCNL	4 (11.2%)
Preschool children	2 (5.6%)
Solitary kidney	1 (2.8%)