Meningocele
☛ Congenital defect in vertebral arches with cystic dilatation of meninges .

Meningomyelocel
☛Congenital defect in vertebral arches with cystic dilatation of meninges and structural or functional abnormality of spinal cord & meninges.

Development
☛ It is developmental abnormality of neural tube.
Defect in

1 . Primary nervation

2. Secondary nervation

• Meningocele is a secondary neural tube defect.
• Meningomyeleocele is primary neural tube defect.
• Encephalocele is the outpouching of dura with or without brain.
• Other neural tube defects
  ☛ Anancephaly, sacral agenesis ,myelocytocele.

Etiology

• Low socioeconomic condition.
• Deficiency of folic acid.
• Hypervitaminoses A.
• Maternal IDDM.
• Chromosomal abnormalities – Trisomy13, 18.
• Intrauterine drug exposure.

Diagnosis

Intra-uterine by USG.
Amniotic fluid fetoprotein assay.
☛ ↑ed Sr. AFP
☛ Postnatal diagnosisis immediately obvious at birth.

Syndromes Associated with Meningomyelocoele

1. Club feet
2. Arnold – chiari syndrome.
3. Hydrocephalous
4. Neurogenic bladder.
5. Musculoskeletal defects
6. Facial clefts
7. Umbilical hernia
8. VACTERL –  Vertebral anomalies , anal atresia , tracheoesophageal fistula, esophageal atresia , renal,Limb anomalies.

☛ Clinical features

• Paraplegia
• Hydrocephalous
• Cranial nerve dysfunction
• Renal failure
• Progressive bony ,spine ,joint deformities.
• Pathological

Pre- operative Examination
☛ Specific history

• Antenatal history of exposure of drugs.
• H/o birth asphyxia due to hydrocephalus
• Seizures
• H/o congenital heart defects.
• Limb movements to r/o paraplegia.

General assessment

• Overall development & nutrition.
• E/O neurological deficit.

Back Examination

• Defect à size ,shape ,location
• Curvature of spine.
• Palpate the deformity like spine bifida
• Latex allergy is known & can cause life threatening reaction and hence caution should be exercised.

Neurological Examinations

• Activity to sensory stimulus
• Reflexes – may be absent
• E/O neurological deficit
• S/O associated hydrocephalous.
• Cranial N involvement.

Airway Assesment

• Rule out facial cleft
• Rule out Arnold chiari malformation à inspiratory stridor, apneic episodes are common
• Rule out associated congenital anomalies.
• Orthopedic opinion – for musculoskeletal deformities, urologic opinion – for renal anomalies.
• Neonatologist – for associated anomalies.

Pre-op investigations

• WBC – can be ↑ ed due to infection
• Platelet count
• Renal function tests.
• Urine routine and microscopy to rule out UTI.
• X-ray chest – to Rule out RTI & cardiomegaly.
• Bl .gr. & cross matching – with large defects, blood loss may be significant.
• CT scan / MRI brain à To Rule out any malformation / hydrocephalous.
• Other specific investigations like 2 D echo – for congenital heart defects, ultrasound of urinary tract, urodynamic studies.

Surgical options If lesion is ruptured-

• Antibiotics
• Coverage with soaked sponges in NS or RL  to avoid desiccation.
• Avoid latex exposure.
• Trendelenberg position
• Prone position – to avoid pressure on lesion
• Monitor for signs of meningitis.

Sx -options

1. In utero – if possible
2. If diagnosed antenatally and in utero sx at possible – early sx is option.

It doesn’t revert the neurological defect but prevent infection.
The defect should be closed within 24 hrs whether or not membrane is intact.

3. Simultaneous repair and shunting à in overt hydrocephalous, meningomyelocoele repair & VP shunt is done simultaneously.

If VP shunt is not performed, an ↑ed risk of meningomyelocoele repair breakdown is present.

Outcome

• With modern treatment 85 % survival.
• Mortality depends upon – associated congenital anomalies.

Peri- operative problems

• Problems related to age – Neonate/infant.
• Problems related to airway

☛ Hydrocephalus
☛ Facial cleft, abnormalities
☛ Paediatric airway.

Problem with associated syndromes

• Hydrocephalous
• Arnold chiari syndrome
• Heart defects
• Renal

Problems with surgery

• Prone position.
• CSF leak
• Blood loss
• Hypothermia
• Nerve studies.

☛ Extreme head flexion may cause brainstem compression.
☛ Venous congestion if abd – compression
☛ Venous congestion of face, eyes, togne &  lung compliance.

Premedication

• Neonates don’t require anxiolytics.
• Infants – midazolam syrup 0.5 mg/kg avoid separation anxiety.
• Ketamine avoided due to associated ↑ICT.

Induction

• Anticipated difficut intubation – intubate on spontaneous Ventilation.
• Scoline avoided due to musculoskeutal abnormalities & in ↑ ICT.
• Normothermia maintained.
• Blood loss and third space loss corrected.

Positioning

• Prone position, acute flexion avoided.
• Avoid pressure on eyes, face, bony points padded.
• Abdomen should be fixed.
• Use of muscle relaxant should be timed properly, in case nerve studies are required.

Monitoring

• Stethoscope in axilla .
• Pulse oximetry.

• Etco2
• Temperature monitoring                                                                              dr.nagesh