How early is early? Effect of oxybutynin on bladder dynamics within the first year of life in patients with spina bifida

Abstract

Introduction: Early proactive treatment of patients with high-risk neurogenic bladder from spina bifida (SB) may preserve renal function and decrease the need for bladder augmentation later in life. Timing of initiation of anticholinergic therapy (AC) medication and clean intermittent catheterization (CIC) is variable and based on imprecise studies. The authors hypothesized that initiation of AC after the initial video-urodynamic study (VUDS) may benefit bladder capacity even in children who do not meet the standard hostile criteria for starting AC.

Study design: A retrospective review of a prospectively maintained VUDS database from August 2015 to March 2019 was performed. Patients with SB who had undergone initial VUDS between 1 and 7 months of age and had a subsequent follow-up study between 9 and 18 months of age were included. Multiple VUDS and clinical parameters including expected bladder capacity, actual capacity reached, pressure at actual capacity, presence of detrusor overactivity, presence of urinary tract dilation and reflux, and whether or not AC was started were extracted and compared. P-value of <0.05 was considered statistically significant.

Results: A total of 69 patients completed an initial study at median age of 2 months, and follow-up study at median age of 13 months. Anticholinergic therapy was started in 21 patients (10 F, 11 M). Decision to initiate AC was at discretion of the attending pediatric urologist performing the VUDS in real time. Changes between the initial and repeat VUDS are listed in the summary table below. Adverse effects of AC were reported in 25% (5/21) patients: urinary retention/UTIs (3), allergic reaction (1), and fatigue (1).

Discussion: The authors findings suggest that AC stabilizes storage pressure for those who initially have a higher storage pressure, while in those with initial low storage pressures, storage pressures worsened over time in the absence of AC. Patients started on AC experienced a faster rate of increase in bladder capacity. Limitations to this study included the unknown long term and sustainability of the improvement in bladder parameters, the lack of uniform criteria for the initiation of AC or CIC, and an unknown long-term degree of upper tract protection.

Conclusion: This study found early initiation of AC in SB at 2 months of age had significant positive effects on growth of bladder capacity and stabilization of storage pressure. However, long-term effects of AC are still undetermined, and thus, longitudinal studies are needed to understand the precise indications for initiation of early AC treatment.

Keywords: Anticholinergics; Myelomeningocele; Neurogenic bladder.