Initial care of newborns with spina bifida centers on preventing bladder and upper tract damage from detrusor leak point pressure of greater than 40 cm H 2 O. The authors recommend using urodynamic-based management to select patients with elevated pressures for anticholinergic therapy and intermittent catheterization (CIC), using diapers and observation with biannual renal sonography for the remainder. At the age of toilet training, children who have urodynamic evidence of uninhibited contractions or rising pressure during filling are started on anticholinergics and CIC, or have their dosage increased until pressures less than 40 cm H 2 O and areflexia are achieved. Sphincter incompetency is diagnosed in incontinent children with pressures less than 40 cm H 2 O and areflexia or stress incontinence. Augmentation is indicated in patients with hydronephrosis or reflux and end-filling pressures or DLPP less than 40 cm H 2 O despite medical management to the point of patient tolerance. A minority of patients, not yet well-defined, will also need augmentation after bladder outlet surgery for similar postoperative indications.
Initial management
In a prior article, the authors reviewed controversies regarding the urologic care of infants diagnosed with neurogenic bladder, primarily caused by spina bifida. Briefly summarized, initial management options include (1) universal institution of anticholinergics and intermittent catheterization (CIC), (2) observation using periodic radiologic imaging, reserving anticholinergics and CIC for infants developing bladder trabeculation, reflux, and/or hydronephrosis, or (3) urodynamic-based management using preemptive anticholinergics and CIC for infants with adverse findings.
Proposed advantages of urodynamic-based management include avoidance of therapy in infants with low intravesical pressures, and prevention of bladder and upper tract damage in those with high pressures. Risk assessment according to bladder pressures is based on the observation by McGuire and colleagues that 80% of patients with intravesical pressures greater than 40 cm H 2 0 at urinary leakage (detrusor leak point pressure [DLPP]) had reflux and/or hydronephrosis. Accordingly, infants with DLPP greater than 40 cm H 2 0, and/or detrusor sphincter dyssynergia believed to be an additional risk factor, have been prescribed anticholinergics and CIC prophylactically rather than at observation of secondary radiologic deterioration.
Although McGuire found a DLPP greater than 40 cm H 2 0 predictive for upper tract risk, others subsequently suggested that sustained intravesical pressures as low as 20 cm H 2 O increase likelihood for bladder damage. Furthermore, how many infants with initially low intravesical pressures will subsequently manifest increased pressures with risk for bladder and upper tract deterioration is unclear, although two reports suggest it occurs in up to 40% of patients, usually within the first 6 months of life. Together, these observations have led to early treatment of more infants.
However, determining DLPP in infants has potential pitfalls, because intravesical pressures vary according to infusion rate and catheter size. Similarly, ability to diagnose detrusor sphincter dyssynergia with commonly used perineal patch electrodes rather than concentric needles has been questioned.
Current Texas Scottish Rite Hospital protocol
The authors perform initial evaluation using renal ultrasound and fluoroscopic urodynamic evaluation at approximately 6 weeks of age, when spinal shock from newborn back closure appears resolved. A 5-French transurethral urodynamic catheter and a rectal balloon are used to measure detrusor and intra-abdominal pressures, respectively. Contrast medium is infused through a pump with a filling rate based on 10% of estimated bladder capacity (approximately 5 mL/min). Infants with areflexic detrusor pressures exceeding 40 cm H 2 0 start oxybutynin (0.2 mg/kg twice daily) and CIC (every 3 hours), with repeat testing within 12 weeks to confirm lower pressures.
The authors do not treat uninhibited contractions (UBC), which can be seen in normal infants, unless baseline pressures before contraction exceed 40 cm H 2 0, nor do they diagnose detrusor sphincter dyssynergia. All others with pressures less than 40 cm H 2 O are observed without active bladder management.
Urodynamic evaluation is repeated at 12 months and approximately 36 months of age. Renal ultrasonography provides surveillance for hydronephrosis every 6 months. Development of hydronephrosis, or new onset of febrile urinary tracts infections, prompts additional fluoroscopic urodynamic evaluation. Data from this protocol are being collected prospectively to document the number of infants diagnosed with high pressures through initial urodynamics at 6 weeks, and the number of patients initially believed to be at low risk who develop high pressures, reflux, or hydronephrosis over time.
Assuming fewer than 10% of children with congenital neurogenic bladder will develop satisfactory bladder control without need for CIC, all parents are initially counseled and reminded at periodic follow-ups to expect this intervention by the age of toilet training if urodynamic evaluation does not indicate earlier management.
Current Texas Scottish Rite Hospital protocol
The authors perform initial evaluation using renal ultrasound and fluoroscopic urodynamic evaluation at approximately 6 weeks of age, when spinal shock from newborn back closure appears resolved. A 5-French transurethral urodynamic catheter and a rectal balloon are used to measure detrusor and intra-abdominal pressures, respectively. Contrast medium is infused through a pump with a filling rate based on 10% of estimated bladder capacity (approximately 5 mL/min). Infants with areflexic detrusor pressures exceeding 40 cm H 2 0 start oxybutynin (0.2 mg/kg twice daily) and CIC (every 3 hours), with repeat testing within 12 weeks to confirm lower pressures.
The authors do not treat uninhibited contractions (UBC), which can be seen in normal infants, unless baseline pressures before contraction exceed 40 cm H 2 0, nor do they diagnose detrusor sphincter dyssynergia. All others with pressures less than 40 cm H 2 O are observed without active bladder management.
Urodynamic evaluation is repeated at 12 months and approximately 36 months of age. Renal ultrasonography provides surveillance for hydronephrosis every 6 months. Development of hydronephrosis, or new onset of febrile urinary tracts infections, prompts additional fluoroscopic urodynamic evaluation. Data from this protocol are being collected prospectively to document the number of infants diagnosed with high pressures through initial urodynamics at 6 weeks, and the number of patients initially believed to be at low risk who develop high pressures, reflux, or hydronephrosis over time.
Assuming fewer than 10% of children with congenital neurogenic bladder will develop satisfactory bladder control without need for CIC, all parents are initially counseled and reminded at periodic follow-ups to expect this intervention by the age of toilet training if urodynamic evaluation does not indicate earlier management.
Management at toilet training age
Classifying the neurogenic bladder into high and low pressures also helps predict continence at toilet training ( Fig. 1 ). Those with baseline pressures greater than 40 cm H 2 0 often become dry with anticholinergics (oxybutynin 0.2 mg/kg three to four times daily) and CIC (every 3 hours) alone. Most patients with high pressures have already been diagnosed and started on this medical regimen as a result of earlier urodynamic study. Those with persistent incontinence undergo repeat testing to determine adequacy of oxybutynin for reducing pressures to less than 40 cm H 2 0 and abolishing UBC. Persistent high pressure or UBC is treated by increasing oral oxybutynin to tolerance and/or adding intravesical instillation of 5 mg twice to three times daily as needed. In unusual cases with continued UBC, Botox injection is recommended. The indication for augmentation is persistent high pressure or UBC despite these medical treatments.
Sphincteric Insufficiency
Children who are incontinent on CIC and/or have a history of stress urinary incontinence and found to have detrusor areflexia and pressures less than 40 cm H 2 O are diagnosed with sphincteric insufficiency. Treatment requires surgical enhancement of outlet resistance using one of several bladder neck (BN) options: injection, reconstruction, sling, artificial sphincter, or closure.
In a series of patients with mixed causes of incontinence and mean follow-up of 28 months, BN injection using dextranomer/hyaluronic acid polymer resulted in a dry interval of 4 hours in 48% of 27 children with neuropathic bladders, 4 of whom underwent failed treatment with slings. Similarly, polydimethylsiloxane injection ended pad use in 34% of 44 children with neurogenic bladders, 24 of whom underwent prior bladder neck procedures, at median follow-up of 28 months. No difference in outcomes was seen between those who underwent prior interventions and those who did not. Both series used a mean volume per injection of approximately 3.5 mL, found that more than 2 additional injections were unlikely to succeed, and noted that the number of patients considered continent declined during the first 12 months and then seemed to stabilize.
BN procedures designed to achieve continence through urethral lengthening for neuropathic outlet incompetency include those described by Kropp and Angwafo and Salle. Each uses the anterior bladder wall to extend the urethra beyond the bladder neck into the bladder, through tubularization versus an onlay-type flap, respectively. Reported outcomes for these reconstructions and various modifications are summarized in Table 1 .
| Authors | Number of Patient (Male/Female) | Mean Follow-up | Number of “Dry” (%) | New Vesicoureteral Reflux (%) | Augmentation | Total (%) | |
|---|---|---|---|---|---|---|---|
| Prior/Simultaneous | Subsequent | ||||||
| Nill et al | 24 (10/14) | 1.5–7 y | 20 (83) | 10 (42) | “all” | ||
| Belman, Kaplan | 18 (10/8) | ns | 14 (78) | 4 (22) | 16 | 1 | 17 (94) |
| Mollard et al | 16 (0/16) | 12–36 mo | 13 (81) | ns a | 7 | 7 (44) | |
| Snodgrass | 22 (13/9) | ns | 20 (91) | 9 (50) b | 19 | 19 (86) | |
| Salle et al | 17 (7/10) | 26 mo | 12 (70) | 2 (12) c | 12 | 1 | 13 (76) |
| Hayes et al | 28 (12/16) | 28 mo | 18 (64) | ns | 23 | 23 (82) | |
a Reimplant for refluxing or insufficient intraureteric distance for tube in 12 patients.
b Six underwent simultaneous reimplant.
c One of ten despite reimplant; one of seven without reimplant.
Fascial sling for neurogenic incontinence was first reported by McGuire and colleagues, and is currently the most commonly used procedure in the United States for this condition in children. Technical aspects in published series vary; for example, McGuire and colleagues described a pubovaginal fascial sling elevated until the bladder neck was observed cystoscopically to close. Others have placed the sling around the bladder neck/proximal urethra in a U or X configuration or 360° wrap, adjusting tension “loosely,” “snug,” or “tight” without cystoscopy. Increase in DLPP averaged approximately 10 to 15 cm H 2 O, regardless of technique. Outcomes are listed in Table 2 .
| Authors | Number of Patients (Male/Female) | Mean Follow-up (mo) | Number of “Dry” (%) | Augmentation | Total (%) | |
|---|---|---|---|---|---|---|
| Prior/Simultaneous | Subsequent | |||||
| Gormley et al | 10 (0/10) | 49 | 10 (100) | 3 | 0 | 3 (30) |
| Bauer et al | 11 (0/11) | 12 | 8 (73) | 4 | 4 (36) | |
| Elder | 14 (4/10) | 12 | 13 (93) | 13 | 13 (93) | |
| Decter | 10 (4/6) | 26 | 5 (50) | 6 | 3 | 9 (90) |
| Walker et al | 17 (8/9) | 16 | 16 (94) | 11 | 11 (65) | |
| Perez et al | 36 (13/23) | 17 | 22 (61) | 35 | 35 (90) a | |
| Kurzrock et al | 24 (15/9) | 9–14 | 19 (79) | 24 | 24 (100) | |
| Barthold et al | 27 (7/20) | ≥12 | 10 (37) | 20 | 2 | 22 (81) |
| Austin et al | 18 (8/10) | 21 | 14 (78) | 6 | 6 (33) | |
| Bugg, Joseph | 15 (1/14) | 10–36 | 9 (60) | 15 | 15 (100) | |
| Castellan et al | 58 (15/43) | 50 | 51 (88) | 58 | 58 (100) | |
| Snodgrass et al | 30 (18/12) | 22 | 17 (57) | 0 | 1 | 1 (3) |
| Chrzan et al | 89 (46/43) | 72 | 42 (47) | 11 | 9 | 20 (22) b |
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