Occult spinal dysraphism and urolithiasis: are patients at higher risk of stone disease?

ABSTRACT

BACKGROUND AND PURPOSE: Spinal dysraphism is associated with urinary-tract dysfunction in severe cases such as meningomyelocele, in part because of incomplete innervation of the lower urinary tract. Patients with meningomyelocele are at higher risk for stone formation, possibly secondary to stasis of urine from aberrant storage and emptying. However, minimal data exist on the risk of stone formation in patients with milder forms of spinal dysraphism. The purpose of this study was to examine whether an association exists between urolithiasis and occult spinal dysraphism (OSD). PATIENTS AND METHODS: All patients who underwent a non-contrast CT scan of the abdomen and pelvis during a 4-month period were included. The final dataset consisted of 374 consecutive patients (195 men, 179 women) with a mean age of 54.2 years (range 18-95 years). Scans were reviewed for evidence of urolithiasis and, independently, for skeletal abnormalities. Patients with urolithiasis included those with a kidney, ureteral, or bladder stone(s). Patients with OSD included those with bifid lumbosacral bony elements, posterior arch defects, or incomplete fusion or non-fusion of S1, S2, or S3. The association between urolithiasis and OSD was examined by calculating series of crude and adjusted odds ratios (ORs) with corresponding 95% confidence intervals (CIs). RESULTS: Of the 374 patients, 135 (36.1%) had urinary calculi, and 83 (22.2%) had OSD. No relation was found between the prevalence of OSD and stone disease (OR 1.22; 95% CI 0.72, 2.08), even after adjusting for potential confounders. CONCLUSION: Unlike severe spinal dysraphism, OSD does not appear to confer an increased risk of stone disease.