Risk factors for upper urinary tract deterioration in adult patients with spina bifida

Neurogenic bladder associated with spina bifida disease remains a major cause for mortality or morbidity due to kidney damages. However, we currently do not know which urodynamic findings are associated with an higher risk of upper tract damages in spina bifida patients. The objective of the present study was to evaluate urodynamic findings associated with functional kidney failure and/or with morphological kidney damages.

A large single-center restrospective study was conducted in our national referral center for spina bifida patients using our patients' files. All urodynamics curves were assessed by the same examinator. Functional and/or morphological evaluation of the upper urinary tract were done at the same moment as the urodynamic exam (between 1 week before and 1 month after). Kidney function was assessed using creatinine serum levels or 24 h urinary creatinine levels (creatinine clearance) for walking patients, or with the 24 h urinary creatinine level for wheelchair-users.

We included 262 spina bifida patients in this study. Fifty-five patients had a poor bladder compliance (21.4%) and 88 of them had detrusor overactivity (33.6%). Twenty patients had a stage 2 kidney failure (eGFR < 60 ml/min) and 81 patients out of 254 (30.9%) had an abnormal morphological examination. There were three urodynamic findings significantly associated with UUTD: bladder compliance (OR = 0.18; p = 0.007), Pdetmax (OR = 14.7; p = 0.003) and detrusor overactivity (OR = 1.84; p = 0.03).

In this large series of spina bifida patients, maximum detrusor pressure and bladder compliance are the main urodynamic findings determinants of UUTD risk.