Editorial Comment

The American Urological Association Guidelines recommend percutaneous nephrolithotomy (PCNL) as the standard of care for patients with staghorn or large renal stones because of the high stone-free rates (SFRs) with minimal morbidity. Before the advent of flexible fiberoptic instruments and Holmium laser lithotripters, it was not unusual for PCNL to require multiple access tracts directly on calyces containing stones to achieve stone-free status. Some authors even suggested performing auxiliary procedures, such as shock wave lithotripsy (SWL) as combination or “sandwich” therapy with PCNL to fragment stones that could not be reached using rigid instruments. However, SFRs were lower when SWL was not followed with PCNL to remove stone fragments. With the invention of flexible nephroscopes and ureteroscopes in addition to the availability of flexible miniaturized lithotripters, such as Holmium laser using 200- or 365-μm fibers, PCNL through a single incision and a single tract (sPCNL) becomes possible for large renal stones and even staghorns. In the above manuscript, the authors present a retrospective series of 351 patients who underwent sPCNL from 2000 to 2010. Although this method was first proposed by Wong and Leveillee, the authors should be commended for their meticulous collection of data over the 10-year period. In addition to limiting the incision to a single site (laparo-endoscopic single site [LESS), they also used a flexible ureteroscope through a natural orifice (urethra) during second-look nephroscopy to access calyces inaccessible using a flexible nephroscope; thus combining LESS with natural orifice transurethral endoscopic surgery (NOTES).