☛ Congenital defect in vertebral arches with cystic dilatation of meninges .
☛Congenital defect in vertebral arches with cystic dilatation of meninges and structural or functional abnormality of spinal cord & meninges.
☛ It is developmental abnormality of neural tube.
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.
- Low socioeconomic condition.
- Deficiency of folic acid.
- Hypervitaminoses A.
- Maternal IDDM.
- Chromosomal abnormalities – Trisomy13, 18.
- Intrauterine drug exposure.
Intra-uterine by USG.
Amniotic fluid fetoprotein assay.
☛ ↑ed Sr. AFP
☛ Postnatal diagnosisis immediately obvious at birth.
Syndromes Associated with Meningomyelocoele
- Club feet
- Arnold – chiari syndrome.
- Neurogenic bladder.
- Musculoskeletal defects
- Facial clefts
- Umbilical hernia
- VACTERL – Vertebral anomalies , anal atresia , tracheoesophageal fistula, esophageal atresia , renal,Limb anomalies.
☛ Clinical features
- Cranial nerve dysfunction
- Renal failure
- Progressive bony ,spine ,joint deformities.
Pre- operative Examination
☛ Specific history
- Antenatal history of exposure of drugs.
- H/o birth asphyxia due to hydrocephalus
- H/o congenital heart defects.
- Limb movements to r/o paraplegia.
- Overall development & nutrition.
- E/O neurological deficit.
- 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.
- Activity to sensory stimulus
- Reflexes – may be absent
- E/O neurological deficit
- S/O associated hydrocephalous.
- Cranial N involvement.
- 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.
- 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-
- 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.
- In utero – if possible
- 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.
- 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.
- With modern treatment 85 % survival.
- Mortality depends upon – associated congenital anomalies.
Peri- operative problems
- Problems related to age – Neonate/infant.
- Problems related to airway
☛ Facial cleft, abnormalities
☛ Paediatric airway.
Problem with associated syndromes
- Arnold chiari syndrome
- Heart defects
Problems with surgery
- Prone position.
- CSF leak
- Blood loss
- Nerve studies.
☛ Extreme head flexion may cause brainstem compression.
☛ Venous congestion if abd – compression
☛ Venous congestion of face, eyes, togne & lung compliance.
- Neonates don’t require anxiolytics.
- Infants – midazolam syrup 0.5 mg/kg avoid separation anxiety.
- Ketamine avoided due to associated ↑ICT.
- Anticipated difficut intubation – intubate on spontaneous Ventilation.
- Scoline avoided due to musculoskeutal abnormalities & in ↑ ICT.
- Normothermia maintained.
- Blood loss and third space loss corrected.
- 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.
- Stethoscope in axilla .
- Pulse oximetry.
- Temperature monitoring dr.nagesh