"Mini-percutaneous" percutaneous nephrolithotomy: technique and indications

Since Helal and Jackman developed the mini-percutaneous ("mini-perc") percutaneous nephrolithotomy (PCNL) for the treatment of pediatric renal lithiasis various authors have used is technique in adults with the aim to preserve renal parenchyma and diminish morbidity associated with the standard PCNL. We describe the surgical technique of "mini-perc" PCNL in the treatment of renal lithiasis. We review various case series from the literature of "mini perc" PCNL for the treatment of adult renal lithiasis, its current indications, percentages of stone free patients, and associated problems, mainly the required instruments. Morbidity associated with "miniperc" PCNL seems to be lower than with the standard PCNL, but the use a smaller calibre tract with the only aim to preserve renal parenchyma does not offer advantages. It is a complementary technique to the standard PCNL; however, the diameter of the percutaneous access is not well defined yet and depends on the calibre of the instruments used.