Urolithiasis in adult spina bifida patients: study in 260 patients and discussion of the literature.

PURPOSE

To describe incidence and risk factors of urinary tract stones in adult spina bifida (SB) patients. Although spina bifida patients have an allegedly higher risk of urinary tract stones, only two small non-English case series are available and do not provide adequate epidemiological data and analyses on risk factors.

METHODS

A total of 260 adult SB patients followed in our centre for 10 years were retrospectively analysed for stone disease. Both a univariate analysis (Fisher's exact, two-sided Student's t test) and a binary logistic regression analysis were performed to identify independent risk factors for stone disease.

RESULTS

Of the 260 patients, 24 (9.2 %) were identified with a history of urolithiasis. Fourteen patients (5.4 %) had bladder stones in 26 episodes. Sixteen patients (6.2 %) had upper urinary tract stones: 14 kidney stones and two ureteral stones. Lifetime incidence of both bladder stones and upper tract stones was 2.25 per 1,000 patient-years. Recurrent urinary tract infections (OR 4.34, p = 0.013) and incorporation of bowel tissue into a continent reservoir (including enterocystoplasty) (OR 4.80, p = 0.012) were independent risk factors for bladder stone disease in a multivariate model. An indwelling catheter was an independent predictor for upper tract stones (OR 5.89, p = 0.02).

CONCLUSIONS

Urolithiasis, especially in the bladder, is a frequent finding in patients with SB. Bladder stones occur about 10 times more often in SB patients than in the population. In patients without risk factors, frequent ultrasound of the urinary tract is not necessary for the sole detection of stones.