Cutting for Stone in Augmented Bladders—What is the Risk of Recurrence and is it Impacted by Treatment Modality?

Abstract

Bladder stones are common after bladder augmentation, often resulting in numerous procedures for recurrence. We sought to determine whether surgical technique and stone fragmentation are significant predictors of bladder stone recurrence after bladder augmentation. We retrospectively reviewed 107 patients treated for first bladder stones at our institution. Patient demographics, details of surgeries, stone therapy and recurrence were reviewed. Kaplan-Meier survival and Cox proportional hazards analysis were used to determine predictors of time to first stone recurrence. Of 107 patients 55.1% were female and 79.4% had neuropathic bladder. Patients underwent augmentation at a median age of 8.0 years (range 2.4 to 22.8) and were followed for a median of 12.4 years (1.8 to 34). Segments used for augmentation included ileum (72.9% of cases), sigmoid (16.8%), cecum/ileocecum (9.4%) and other (ureter, stomach/ileum, 1.8%). Bladder neck procedures were performed in 63.6% of patients and catheterizable channels in 75.7%. First stone surgery occurred at a median of 3.1 years after augmentation (range 5 months to 21.8 years). Endoscopy was used in 66.4% of cases and open cystolithotomy in 33.6%. Overall 47.7% of stones were fragmented. Bladder stones recurred in 47.7% of patients (median recurrence time 9.5 years, range 3 months to 14.7 years). Recurrence risk was greatest in the first 2 years postoperatively (12.1% per patient per year, p = 0.03). Recurrence risk did not change with technique (endoscopic vs open) or fragmentation, even after controlling for surgical and clinical variables. Bladder stones recurred in almost half of the patients at 9 years postoperatively independent of treatment technique and patient characteristics. As a high risk group, yearly x-ray of the kidneys, ureters and bladder, and ultrasound of the kidneys and bladder are recommended in these patients.