Age-based risk of end-stage kidney disease in patients with myelomeningocele

Abstract

Objective We aimed to quantify end-stage kidney disease (ESKD) risk after infancy in individuals with myelomeningocele (MMC) followed by urology in the modern medical era and to assess if ESKD risk was higher after surgery related to a hostile bladder.

Methods We retrospectively reviewed patients with MMC followed by urology at our institution born ≥ 1972 (when clean intermittent catheterization was introduced) past 1 year of age (when mortality is highest, sometimes before establishing urology care). ESKD was defined as requiring permanent peritoneal/hemodialysis or renal transplantation. Early surgery related to hostile bladder included incontinent vesicostomy, bladder augmentation, detrusor Botulinum A toxin injection, ureteral reimplantation, or nephrectomy for recurrent urinary tract infections. Survival analysis and proportional hazards regression were used. Sensitivity analyses included: risk factor analysis with only vesicostomy, timing of surgery, including the entire population without minimal follow-up (n = 1054) and only patients with ≥ 5 years of follow-up (n = 925).

Results Overall, 1029 patients with MMC were followed for a median of 17.0 years (49% female, 76% shunted). Seven patients (0.7%) developed ESKD at a median 24.3 years old (5 hemodialysis, 1 peritoneal dialysis, 1 transplantation). On survival analysis, the ESKD risk was 0.3% at 20 years old and 2.1% at 30 years old (Figure). This was ∼100 times higher than the general population (0.003% by 21 years old, p < 0.001). Patients who underwent early surgery for hostile bladder had higher ESKD risk (HR 8.3, p = 0.001, 6% vs. 1.5% at 30 years). On exploratory analyses, gender, birth year, shunt status and wheelchair use were not associated with ESKD risk (p ≥ 0.16). Thirty-year ESKD risk was 10% after early vesicostomy vs. 1.4% among children without one (p = 0.001). Children undergoing bladder surgery between 1.5 and 5 years old had a higher risk of ESKD. No other statistically/clinically significant differences were noted.

Comment Patients with MMC remain at risk of progressive renal damage throughout life. We relied on the final binary ESKD outcome to quantify this risk, rather than imprecise glomerular filtration rate formulas. Analysis was limited by few people developing ESKD, inconsistent documentation of early urodynamic findings and indications for bladder-related surgery.

Conclusions While ESKD is relatively uncommon in the MMC population receiving routine urological care, affecting 2.1% of individuals in the first 3 decades, it is significantly higher than the general population. Children with poor bladder function are likely at high risk, underlining the need for routine urological care, particularly in adulthood.