Spinal dysraphism
Key points
Spinal dysraphism is a group of congenital spinal anomalies resulting from defective closure of the neural tube during embryonic development
Includes spina bifida occulta, meningocele, and myelomeningocele
Most cases have Chiari II malformation and hydrocephalus, requiring VP shunt
Pathophysiology
Notochord, neural plate development then neural tube closure throughout week 3
Open vertebra and herniated cord at any level
Commonly lumbosacral spine
Dura mater fuses to dermis, pia mater to epidermis
Sacral dimples
If near coccyx and can see bottom - no need to refer
If higher e.g. Lumbar - always refer
If dimple in gluteal cleft, normal
If outside cleft, abnormal
If associated with cutaneous lesion, image
Bifurcated cleft is abnormal
Could indicate:
Tethered cord
Dermal sinus tract - risk of meningitis
Tethered cord
60% have normal urodynamics in infancy but only 20% at 3 years
25% risk of retethering
Need to continuously monitor as per spina bifida
USS if below 3 months
MRI spine if older
Abnormal urodynamic findings due to tethering of the cord:
Revert to normal in 60% of babies postop
Improvement in 30%
Worsening in 10%
Older children 27% each become normal, improve or stabilise while the remaining 19% worsen
Management of myelomeningocoele study (MOMS)
Inclusion criteria:
Singleton pregnancy
Myelomeningocele with upper boundary located between T1 and S1
Evidence of hindbrain herniation
Gestational age of 19.0–25.9 weeks at randomization
Normal karyotype
Exclusions:
Fetal anomaly unrelated to myelomeningocele
Severe kyphosis
Risk of preterm birth (including short cervix and previous short-term
birth)
Placental abruption
Body mass index greater than or equal to 35
Results:
68% in antenatal repair required VP shunt vs 98% in postnatal repair
Higher risk of preterm labour in antenatal group
42% antenatal walking at 30 months vs 21% postnatal
Foetal surgery for spina bifida may reduce need for CIC between 6-10 years of age - otherwise no major benefits for urinary function
Outcome of spina bifida
30% die before adulthood due to respiratory, urinary, and neurological complications
Sildenafil for erectile dysfunction - 80% effective
Spinal cord tethering after operation 3-5% - may manifest as changes in urodynamic profile
Standard scenario
Responsibility for long term bowel and bladder management to protect renal function
Ensure child is resuscitated and sepsis treated
Wrap defect
Nurse on side or prone
Call neurosurgeons
Antenatal history
Check for renal tract and other abnormalities
Check if counselling has taken place
If has had antenatal closure:
No benefits for bladder function but reduced need for VP shunt and increased mobility
Examination
Dysmorphic features
Abdomen + Genitalia + testes + Anus (OEIS) complex
At time of back closure - place indwelling urethral catheter
Keep for 1 week post op to allow spinal shock to resolve and analgesia to be weaned
Management following BAPU consensus paper
When stable post op:
USS KUB + renal function
Prophylactic antibiotics only if upper tract changes
Start CIC for all patients (No consensus, but will allow parents and child to get used to it)
Home when parents comfortable with CIC
Follow up with USS, DMSA if upper tract changes, and bladder diary in 3 months
Measure head circumference
Video urodynamics early - to predict hostile poorly compliant bladder that needs increased surveillance or drainage + VUR - start oxybutynin if in this case (not in BAPU consensus)
Joint review in nephro-urology clinic with Urology nurses - do post void bladder scan, check technique for CIC
Manage constipation - may need ACE/Caecostomy or rectal irrigation
Counsel about long term management including Mitrofanoff, bladder augment in later childhood
Aim to continue with yearly USS
Reserve urodynamics for those with clinical or radiological changes
Ladder if worsening renal function/upper tract dilatation/UTI on CIC
1. Check parents technique, manage constipation
2. Start prophylactic antibiotics, or review cultures and change antibiotics if already on
3. Oxybutynin
4. Add tolterodine/Solifenacin
5. Botox
6. Suprapubic catheter - drainage overnight, cycle bladder in day
7. Bladder augment if other measures fail and patient age >6 (ideally >12 and able to manage well)
High risk for obesity, refer early to dietician if needed
References
Brea CM, Munakomi S. Spina Bifida. [Updated 2023 Aug 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559265/
https://remedy.bnssg.icb.nhs.uk/children-young-people/neonatal/sacral-dimples-and-pits/
Weisbrod LJ, Thorell W. Tethered Cord Syndrome (TCS) [Updated 2023 Jul 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK585121/
Adzick NS, Thom EA, Spong CY, Brock JW 3rd, Burrows PK, Johnson MP, Howell LJ, Farrell JA, Dabrowiak ME, Sutton LN, Gupta N, Tulipan NB, D'Alton ME, Farmer DL; MOMS Investigators. A randomized trial of prenatal versus postnatal repair of myelomeningocele. N Engl J Med. 2011 Mar 17;364(11):993-1004. doi: 10.1056/NEJMoa1014379. Epub 2011 Feb 9. PMID: 21306277; PMCID: PMC3770179.
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.