Neuropathic bladder

Key points

Bladder anatomy

Sympathetic – hypogastric nerve (T12 – L2) bladder filling - detrusor relaxation

Parasympathetic – pelvic nerve (S2-S4) - bladder emptying - contraction of the detrusor

Somatic – pudendal nerve (S2-4) supplies external urethral sphincter - voluntary

Arteries:

Superior (from patent part of umbilical artery remnant) and inferior vesical from internal iliac

Veins:

Venous plexus

Bladder capacity calculations:

 <2 years old: Kg x 8

2-12 year olds: (Age+2) x 30

Post void residual of <10% expected capacity is acceptable

Classify neuropathic bladder by over/underactive detrusor/sphincter:

Management aims

1. Protect kidneys

2. Control of dryness

Management of:

Overactive detrusor: Anticholingergics, Botox, Bladder augment

Underactive detrusor: clean intermittent catheterisation (CIC), diversion e.g. suprapubic catheter (SPC)

Overactive sphincter: CIC, diversion

Underactive sphincter: Bladder neck continence procedures (beware high pressure setrusor post op)

Terminology: Detrusor Sphincter Dyssynergia should only be used in the context of neuropathic bladder. If not neuropathic, it should be termed bladder dysfunction

2016 BAPU consensus paper

Reserve urodynamics for only those with clinical or radiological complications

Yearly USS KUB for stable patients (no consensus on DMSA)

50:50 consensus for CIC for all spina bifida patients

50:50 consensus for routine anticholinergics for patients on CIC

Botox injection acceptable for use

Ileum first choice for augment

Post augment DMSA and cystoscopy for malignancy only when clinically indicated

Bladder Augmentation

Ideally older patients (but can do it at age 6-7 if sensible) wishing to achieve continence, or with unsafe bladder not responding to Anticholinergics/Botox

Criteria:

Bladders <50% of expected capacity

Reduced compliance <10ml/cm H2O

Detrusor fill pressure >40 cmH20

High leak point pressure >35 cm H2O

Mitrofanoff: easier catheterisation e.g. overweight patients in wheelchair, more socially acceptable

Do they need ACE at same time - in which case will need Monti

Grafts for augment:

Ileum - best

Colon - slightly higher risk of cancer compared to ileum, more mucus production

Gastric - high risk of cancer, difficult to mobilise

Method:

Midline laparotomy - can extend, better for reoperations

Take 30cm ileum, 30cm from ICJ

Can open bladder AP or transverse

Catheterise UOs continue incision to within 1cm of UOs

What to do with bladder neck? : bulking reflux, sling, closure

SPC as part of anastomotic line

Mitrofanoff- do from umbilicus to anterior bladder - able to find and catheterise umbilicus with proprioception

Complications

Stenosis of Mitrofanoff if not in use

Hyperchloraemic metabolic acidosis

B12 deficiency if terminal ileum used

Long term

Bladder stones (do USS yearly), from mucous production, prevented by daily washouts with or without NAC, internal hernia/volvulus, rupture/leak

Can do gentamicin washouts for recurrent UTI

Cancer risk not higher than non-augmented bladders in spina bifida but worse if needing transplant immunosuppression - consider cystoscopy before transition in old reconstructions

Bladder functional voiding disorders

Giggle incontinence

Narcolepsy spectrum

Management: Bladder training and emptying + methylphenidate

Non-Neuropathic neuropathic bladder

Hinmans syndrome

Classic Xmas tree appearance

Usually history of domestic turmoil around age of toilet training - overuse of external sphincter

Manage as usual neuropathic bladder

Diurnal urinary frequency

Males age 4-7

Resolves after <3 months

"Lazy bladder"

Low pressure retention in girls

Resolves at puberty

Void infrequently or void just enough to relieve the pressure

MCUG - larger-than-normal capacity bladder high residual volumes

Treatment - changing voiding habits, rarely CIC

Small capacity hypertonic bladder

Inflammation of the bladder wall secondary to recurrent UTIs causes detrusor irritability

‘stop and start’ voiding

MCUG - thickened and trabeculated bladder wall, dilated urethra- ‘spinning top deformity’

Treatment - long-term prophylactic antibiotics, oxybutynin for 6–9 months

Standard scenario

Dysfunctional voiding/Incontinence

Concerns:

1. Underlying anatomical issue

2. Psychological effects on patient and family

History:

Classify day/night/both

Primary/secondary

Other LUTS

UTI/Haematuria

Fluid intake and especially around bedtime

Problem with waking?

Constipation

Systemic features - diabetes

Examination:

Abdomen for faecalomas and bladder

External genitalia for phimosis/labial adhesions

Spine

Investigations:

Urine dip

Bladder diary

USS + pre, post void if cause not obvious from history - looking for duplex and bladder emptying

Management:

Manage bladder/bowel dysfunction/fluid intake pattern

Oxybutynin if daytime problems or bladder capacity

Desmopressin if not

(Vasopressin acts on V1 (vasoconstriction) and V2 receptor (aquaporins) Desmopressin acts on V2 only)

Nocturnal enuresis alarm if problems waking and family motivated

ERIC website

Urodynamics if compliance and no improvement

References

Lee B, Featherstone N, Nagappan P, McCarthy L, O'Toole S. British Association of Paediatric Urologists consensus statement on the management of the neuropathic bladder. J Pediatr Urol. 2016 Apr;12(2):76-87. doi: 10.1016/j.jpurol.2016.01.002. Epub 2016 Jan 29. PMID: 26946946.

Verpoorten, C., Buyse, G.M. The neurogenic bladder: medical treatment. Pediatr Nephrol 23, 717–725 (2008). https://doi.org/10.1007/s00467-007-0691-z

Succeeding in Paediatic Surgery Examinations Volume 1 2012, Chapter 60 Neurogenic Bladder A Rajimwale