Predictive factors for percutaneous nephrolithotomy outcomes in neurogenic bladder population

To review experience performing percutaneous nephrolithotomy (PCNL) on patients with neurogenic bladder, evaluating predictors for increased length of stay (LOS), intensive care unit (ICU) stay, stone-free rate, and number of procedures and outcomes measures between spinal cord injury (SCI) and spina bifida (SB) patients.

We retrospectively reviewed our PCNLs from January 1, 2002 to December 31, 2009 and identified 47 patients. Data collected included LOS, ICU stay, stone-free rate, complications, and total procedures.

A total of 66 PCNLs were performed on 47 patients. The mean LOS was 5.3 days, and nine patients needed ICU stay (mean 13.9 d). Initial stone-free rate was 60.6%, and final stone-free rate was 69.7%. Multiple access was associated with increased LOS (P=0.01), ICU stay (P<0.01), transfusion (P<0.01), and pulmonary complications (P=0.03). Upper-pole access was associated with decreased initial stone-free rate (P=0.04). Midpolar access predicted increased final stone-free rate (P=0.04). Mean stone size was 3.31 cm and was predictive of an increased number of procedures (P=0.04). Larger stone size was also predictive of decreased initial stone-free rate (P=0.03) and final stone-free rate (P=0.05). There were no statistically significant differences between SCI and SB patients in terms of outcomes.

Increasing stone size and multiple access were predictors of adverse outcomes, and location of access affected stone-free status. We found no differences in outcomes between SB and SCI patients. To our knowledge, this is the largest series reported regarding PCNLs in this patient population.