Super-mini PCNL (SMP): Material, indications, technique, advantages and results

To introduce an emerging technique termed 'super-mini- percutaneous nephrolithotomy' (SMP) and describe its application in practice.We described the technique of SMP in the treatment of renal stones with emphasis on the material, indications, technique procedure, advantages, and results.SMP refers to a 7 Ch. nephroscope placed through a 10-14 Ch. metal access sheath with functions of both irrigation and suction-evacuation, to achieve stone fragmentation via laser or pneumatic lithotripsy. We reported our experience of this technique in 342 cases including 231 adults and 111 children. The mean stone size was 2.3 ± 0.9 cm resulted in 54.3 ± 27.7 min of mean operative time in adults, as well as 39.4 ± 26.2 min for stone size of 1.4 ± 0.5cm in children. In parallel, the initial stone-free rate (SFR) was 89.2% and 90.0% followed with a 94.4% and 95.5% of final SFR at 3 months in adults and children, respectively. No transfusions were needed in all patients. Tubeless was achieved in 93.9% and 100%of patients in adults and children respectively. The mean hospital stay was 2.3 ± 0.8 d and 2.7 ± 1.5 d respectively.SMP are suited for stones less than 2.5 cm in size. It is also suited for special situations such as pediatric moderate-sized stones, previously failed SWL or RIRS approaches. It has advantages of a shorter operative time and hospital stays, with a largely reduction use of drainage catheter after procedure. The indications of the SMP may also compete with those of SWL and RIRS.