Objective: To introduce an emerging technique termed 'super-mini- percutaneous nephrolithotomy' (SMP) and describe its application in practice.
Methods: We described the technique of SMP in the treatment of renal stones with emphasis on the material, indications, technique procedure, advantages, and results.
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.
Conclusions: 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.