[Technique, indications, and results of "mini-percutaneous" nephrolithotomy]

In 1997, Jackman and Helal described a miniaturized PCNL technique in children using an 11 F introducer sheath: "mini-percutaneous" nephrolithotomy. Preliminary studies showed that the success rate of this new technique for stones less than 20 mm diameter was comparable to that of standard PCNL. Jackman reported a success rate of 85% in children. In adults, using a 13 F sheath, Chan reported a success rate of 94% in 17 patients and Jackman reported a success rate of 92% in 11 patients. With a 20 F sheath, Monga reported a success rate of 90% in 21 patients. All authors emphasized the value of a small calibre sheath (11 to 20 F) to decrease the morbidity and parenchymal lesions associated with conventional PCNL. However, no randomized prospective study has compared the morbidity of the two types of access. The repercussions of "mini-percutaneous" nephrolithotomy and conventional PCNL (11 F versus 30 F) on the renal parenchyma were recently evaluated. No significant difference in terms of parenchymal scarring was demonstrated. The volume of damaged renal parenchyma represented less than 1% of the total volume for the two types of access. There is therefore no advantage to use a small calibre nephrolithotomy exclusively 2 to preserve the renal parenchyma. This article reviews this new technique, its indications and its results.