[Tasa libre de litos sin complicación mayor como definición de éxito en nefrolitotomía percutánea]

Success in percutaneous nephrolithotomy (PCNL) is defined as a stone-free status; however, major complications are highly common and have been reported as a secondary outcome.

To propose a new definition of PCNL success that comprises a stone free rate without major complications and a risk scale to predict this outcome.

Historical cohort of patients undergoing PCNL. The included variables were age, gender, urine culture, Charlson's comorbidity index (CCI) and complex stones. Success was defined as a stone free status with or without Clavien grade ≤ 2 complication; intermediate success: with stones, with or without Clavien grade ≤ 2 complication; and failure: with or without stones with Clavien grade ≤ 2 complication. Bivariate analysis was performed to identify which factors are associated with the outcome. The independent weight of each factor was calculated by multiple logistic regression analysis.

568 procedures were included, 59% of which were in females. Median age was 49 years; 65%, 22% and 13% of cases were classified as success, intermediate success and failure, respectively. Female sex, positive urine culture, complex stones and severe CCI were associated with failure.

The likelihood of success was directly proportional to the number of risk factors.