Risk determination for upper urinary tract damage in children with neuropathic bladder

Neuropathic bladder dysfunction (NBD) or neurogenic lower urinary tract dysfunction occurs as a result of a lesion at any level of central nervous system. The most common aetiology of NBD in children is abnormal development of spinal column. These defects cause neurogenic detrusor overactivity which contributes to detrusor-sphincter dysfunction and results in lower urinary tract symptoms such as incontinence. One of the more progressive and insidious, at the same time preventable result of neuropathic bladder is upper urinary tract deterioration. It is vital to aim reduction in bladder pressures and the minimisation of urine stasis in order to prevent or at least attenuate renal disease. Despite world-wide strategies for prevention of neural tube defects currently, we will still be involved in the care of spina bifida patients born every year with a neuropathic bladder and at risk of long-term renal damage. This study was planned for evaluation of results and detection of possible risk factors for upper urinary tract deterioration during routine visits of neuropathic bladder population.

The electronic medical records of the patients who were followed up for at least 1 year with the diagnosis of neuropathic bladder in Pediatric Urology and Nephrology units of Adana City Training and Research Hospital were reviewed retrospectively. A total of 117 patients, whose blood, urine, imaging and urodynamic study required for the evaluation of nephrological and urological status were completed and included in the study. Patients under the age of one were excluded from the study. Demographic characteristics, medical history, laboratory and imaging results were recorded. All statistical analyses were analysed by SPSS version 21 software package and analysed by descriptive statistical.

Of the 117 patients who participated in the study, 73 (62.4%) were female and 44 (37.6%) were male. Mean age of the patients was 6.7 ± 4.9 years. The leading cause of neuropathic bladder was neuro-spinal dysraphism with 103 (88.1%) patients. Urinary tract ultrasound imaging revealed hydronephrosis in 44 patients (35.9%), parenchymal thinning in 20 patients (17.1%), increased parenchymal echo in 20 patients (17.1%) and trabeculation or increase in wall thickness of the bladder in 51 patients (43.6%). Voiding cystogram revealed the presence of vesicoureteral reflux in a total of 37 patients (31.6%), with 28 patients being unilateral and 9 patients bilateral. More than half of the patients had abnormal bladder findings (52.1%). In the Tc 99 m DMSA scan of the patients, 24 patients (20.5%) had unilateral renal scars and 15 (12.8%) had bilateral. Loss of renal function was detected in 27 (23.1%) of the patients. Urodynamic study revealed decreased bladder capacity in 65 patients (55.6%) and increased detrusor leakage pressure was found in 60 patients (51.3%). The mean leak point pressure of the patients was 36 ± 26 cm H₂ O, and the mean leakage volume was determined as 157 ± 118 mL.

Findings obtained from imaging and urodynamic studies during routine investigation of neuropathic bladder patients can be a guide for the upper urinary tract. According to our results, age, bladder changes in ultrasound and voiding cystogram, high leak point pressure obtained during urodynamic studies are thought to have strong correlation with upper urinary tract damage. The prevalence of progressive chronic kidney disease in children and adults with spina bifida is remarkable and completely preventable. The strategies for prevention of renal disease in this patient population should be planned by coordinated work of urologist with nephrologist and requires family cooperation.