Success in treating renal calculi with single-access, single-event percutaneous nephrolithotomy: Is a routine "second look" necessary?

Background and Purpose: Percutaneous nephrolithotomy (PCNL) is an effective procedure for the treatment of large renal calculi. An important consideration for patients undergoing PCNL is the management of any residual stone burden, which may include "second-look" nephroscopy. The utility of this practice is unproven, and we present our data on a series of patients in which second-look procedures were not performed. Patients and Methods: We retrospectively reviewed the records of 43 consecutive patients undergoing a total of 45 procedures by a single surgeon at a tertiary-care center. Patients were considered stone free if no calculi were evident by either plain film or noncontrast CT scan. Statistical analysis was used to look for correlations between radiographic stone clearance and various patient and stone characteristics. Results: Of these procedures, 15% had immediate postoperative evidence of residual fragments. At a mean follow-up of 8 months, 32.5% had residual or recurrent stone. There were statistically significant correlations between both patient age and stone size and the risk of recurrent or residual stone. Conclusions: In our study, PCNL was effective for the single-stage treatment of large renal calculi. Aggressive stone clearance obviated the need for routine second-look nephroscopy. Factors leading to an increased risk of residual or recurrent calculi included the presence of a staghorn calculus and younger patient age. The excellent stone-free rates achieved suggest that routine second-look nephroscopy may not be necessary for the majority of patients undergoing PCNL.