Staghorn calculi treated by percutaneous nephrolithotomy: risk factors for recurrence.

Since 1985 our primary mode of therapy for staghorn calculi has been by percutaneous nephrolithotomy. Between January 1985 and June 1988 we have treated 57 cases using this method. We reviewed the rate of recurrence at a minimum of one-year follow-up and observed a 17 percent recurrence rate. Factors identified that were associated with an increased rate of recurrence were: positive urine cultures during follow-up (55% recurrence vs 12%); stone remnant greater than 5 mm (27.3% recurrence vs 13.8%); and stone complexity (25% recurrence for complex or complete staghorn vs 9.7% for noncomplex or partial staghorn). By identifying these risk factors we think that stone recurrence can be reduced and, with close follow-up, detected earlier to permit less invasive therapy if needed.