Proactively managed myelmomeningocele patients undergo urodynamic testing, renal ultrasound, and voiding cystometrogram during infancy to assess for elevated bladder pressures, vesicoureteral reflux, and/or hydronephrosis. Although these results often impact clinical decision making, the significance of those findings remains undefined. We hypothesized that infants born with elevated bladder pressures, vesicoureteral reflux, and/or hydronephrosis have persistent risk of upper tract damage despite early initiation of clean intermittent catheterization and pharmacotherapy, thus carry higher odds of requiring augmentation cystoplasty in the future.

We retrospectively identified all patients with myelomeningocele followed since infancy at a single institution from 1984 to 2017. Infancy was defined as younger than 1 year of age. All patients underwent cystometrogram, voiding cystourethrogram, and renal ultrasound during infancy. Patients with persistently elevated bladder pressures despite clean intermittent catheterization and pharmacotherapy underwent augmentation cystoplasty to prevent upper tract damage. Socially unacceptable urinary incontinence significantly bothersome to the patient was also an indication for augmentation cystoplasty. Patients without at least 8 years of follow-up were excluded from our study. 

The primary outcomes were augmentation cystoplasty, augmentation cystoplasty due to persistently elevated bladder pressures, and augmentation cystoplasty for urinary incontinence. Chi-square analysis was performed to assess whether presence of detrusor leak point pressure or end fill pressure (DLPP/EFP) above 40 cm H2O, vesicoureteral reflux, or hydronephrosis during infancy were more likely to undergo augmentation cystoplasty, augmentation cystoplasty due to persistently elevated bladder pressures, or augmentation cystoplasty for urinary incontinence. If univariate analysis was significant for the given dependent variable, a binary logistic regression was run with DLPP/EFP above 40 cm H2O, vesicoureteral reflux, and hydronephrosis during infancy as the independent variables.

The study included 111 patients with a mean follow up time of 17.0 years (SD 6.6 years). Augmentation cystoplasty was performed in 27 patients (24.3%). The primary indication for augmentation cystoplasty was worsening bladder pressures in 17 (63.0%) patients while 10 (37.0%) underwent surgical intervention to achieve urinary continence. Patients with DLPP/EFP above 40 cm H2O and vesicoureteral reflux during infancy were more likely to undergo augmentation cystoplasty for elevated bladder pressures (p = 0.04, p = 0.05, respectively). Patients with hydronephrosis during infancy were not more likely to undergo augmentation cystoplasty for elevated bladder pressures (p = 0.97). 

Binary logistic regression revealed that patients with infancy DLPP/EFP above 40 cm H2O (p = 0.02, OR 3.75, 95% CI 1.20 – 11.72 ) and vesicoureteral reflux (p = 0.03, OR 3.48, 95% CI 1.11 – 10.92) are predictive of future augmentation for high pressure bladder, while infant hydronephrosis (p=0.53, OR 0.62, 95% CI 0.14 – 2.74) is not.  Alternatively, myelomeningocele infants with DLPP/EFP above 40 cm H2O, vesicoureteral reflux, or hydronephrosis were not more likely to undergo augmentation cystoplasty for urinary incontinence (p = 0.40, p = 0.55, p = 0.12) or augmentation cystoplasty in general (p = 0.24, p = 0.23, p = 0.28, respectively) compared to their counterparts.

Our findings demonstrate that myelomeningocele infants with elevated DLPP/EFP or vesicoureteral reflux are at higher risk of later augmentation for the indication of persistently elevated bladder pressures. Nonetheless, it should be noted that the majority of patients with DLPP/EFP greater than 40 cm H2O and presence of vesicoureteral reflux during infancy did not undergo augmentation cystoplasty, regardless of indication. Thus, patients requiring augmentation remain in the minority despite the presence of risk factors. Pediatric urologists can counsel parents and guardians that the majority of myelomeningocele patients respond to clean intermittent catheterization and pharmacotherapy until adulthood, regardless of infant testing results. 

Augmentation cystoplasty rates for proactively managed myelomeningocele patients may be higher than previously reported when including urinary incontinence as an indication for surgical intervention. Kaefer et al and Wu et al (references) have reported augmentation rates of 10.9 and 16.7%, respectively, but the average age of follow-up in those studies were 8.6 and 11.9 years, respectively, and urinary incontinence was not included as an indication for surgical intervention. Long-term, longitudinal follow-up of our myelomeningocele population allowed us to capture a realistic rate of augmentation until adulthood. Our findings highlight the fact that there will be parents and patients who will undergo augmentation with the primary goal of improving quality of life and gaining independence. This is a pertinent finding in the setting of growing emphasis on improving quality of life and independence in the aging myelmomeningocele population.

Ultimately, these findings will help pediatric urologists counsel parents and guardians during infancy and beyond. If infant test results reveal elevated pressures and vesicoureteral reflux, it would be appropriate to counsel parents and guardians on the importance of adherence to proactive management strategies given the higher risk for future augmentation cystoplasty due to persistently elevated bladder pressures. It should be expected that despite proactive management, a select group of patients will require surgical intervention to prevent upper tract damage. In addition, with a growing emphasis on improving quality of life and independence among patients with myelomeningocele, surgical intervention should remain an option with the goal of achieving urinary continence. Evaluating the value and significance of urodynamic testing and imaging studies during infancy may be more accurately and objectively studied with rigorously designed standardized clinical pathways that include long-term outcomes, but until then, our findings provide useful information for pediatric urologists providing care for myelomeningocele children.

Kaefer M, Pabby A, Kelly M, Darbey M, Bauer SB. Improved bladder function after prophylactic treatment of the high risk neurogenic bladder in newborns with myelomentingocele. The Journal of urology. Sep 1999;162(3 Pt 2):1068-1071.
Wu HY, Baskin LS, Kogan BA. Neurogenic bladder dysfunction due to myelomeningocele: neonatal versus childhood treatment. The Journal of urology. Jun 1997;157(6):2295-2297.