PD05-06: Prospective Randomized Trial of 2 Weeks vs 3 Months of Postoperative Antibiotics after Percutaneous Nephrolithotomy in Complex Patients with Infection-Related Kidney Stones.

Ben Chew*, Alina Reicherz, Vancouver, Canada, Amy E. Krambeck, Chicago, IL, Nicole Miller, Ryan Hsi, Nashville, TN, Kymora Scotland, Los Angeles, CA, David Miller, Pittsburgh, PA, Ryan Paterson, Victor KF Wong, Vancouver, Canada, Michelle Semins, Pittsburgh, PA, Dirk Lange, Vancouver, Canada

Introduction: Struvite kidney stones are associated with bacterial urinary tract infections (UTIs) and cause disproportionate mortality (up to 67%). Treatment of infection stones requires complete surgical stone removal followed by antibiotic therapy to reduce stone recurrence. The optimal duration of antibiotic therapy is unknown. We sought to determine if two weeks or three months of antibiotics post percutaneous nephrolithotomy (PNL) for infection stones resulted in better outcomes for stone recurrence and infection.

Methods: This multi-center, prospective randomized trial evaluated patients with the clinical diagnosis of infection stones.  Patients were randomized to two weeks or three months of postoperative oral antibiotics (nitrofurantoin or culture-specific antibiotic) if stone free or with residual fragments = 4mm on CT after PNL. CT and urine culture were performed at 3-, 6- and 12-months post-procedure. The study was powered to 80%, with 11 patients in each group.

Results: Thirty-eight patients were enrolled and randomized to either two weeks (n = 20) or three months (n=18) of antibiotic therapy post-PNL. Eleven patients were excluded due to residual fragments, and 3 patients were lost to follow-up. Age (49.4±5.0 vs 55.1±5.8y), BMI (29.5±2.3 vs 32.5±3.9kg/m2) and maximal stone diameters (22.4±2.3 vs 27.4±5.2 mm, p=0.36) were all similar. At 3-, 6-, and 12-months follow-up, positive urine cultures were 50.0% vs 37.5%, 50.0% vs 83.3%, and 37.5% vs 100% between 2 week and 3 month groups, respectively (p = ns).  At 3-, 6-, and 12-months follow-up, stone-free rates were 72.7% vs 80.0%, 70.0% vs 57.1%, 80.0% vs 57.1% (p = ns), between two week and three month groups, respectively.

Conclusions: For patients with stone removal following PNL, two weeks of postoperative oral antibiotics are sufficient to prevent stones and recurrent UTI. No significant difference was observed in stone-free rates or recurrent UTI comparing two weeks versus three months of postoperative antibiotics.

Source of Funding: None