Anesthetic management of spina bifida

Anesthetic management of spina bifida

1. Anesthetic Management of Tethered spinal cord syndrome and myelomeningocele Saeid Safari, MD. Assistant Prof. of Anesthesiology, Functional Neurosurgery Research Center, Shahid Beheshti University Of Medical Sciences, Tehran, Iran

2. Congenital and Degenerative Diseases of the Vertebral Column and Spinal Cord Spina Bifida Occulta Meningocele Myelomeningocele Tethered Spinal Cord Syndrome

3. Spina Bifida Occulta Incomplete formation of a single lamina in the lumbosacral spine without other abnormalities. A congenital defect that is present in an estimated 5% of individuals.

4. Spina Bifida Occulta It usually produces no symptoms and is often discovered as an incidental finding on radiographic examination during evaluation of some other unrelated disease process. Because there are no associated abnormalities, an increased risk with spinal anesthesia is not expected, and large numbers of these patients have undergone spinal anesthesia safely.

5. Meningocele and Myelomeningocele Failure of the neural tube to appropriately close in the caudal segments results in neural tube defects . Herniation of contents of the spinal canal result in meningocele and myelomeningocele if the herniated contents contain only meninges and cerebrospinal fluid (CSF) versus meninges, CSF,  and  neural elements, respectively.

6. pseudomeningocele A collection of CSF that does not contain meninges or neural elements and Usually results from trauma or surgery.  

7. Meningocele and Myelomeningocele Meningocele is relatively rare and usually associated with a lower incidence and severity of neurologic deficits. Myelomeningocele is the most common severe congenital anomaly of the spine. Although it usually occurs in the lumbosacral region, myelomeningocele can also occur in cervical or thoracic regions of the vertebral column and cord.

8. Myelomeningocele Increased risk for this defect is associated with maternal folate deficiency. Trisomy 13 , trisomy 18 , and type II Chiari malformations. Hydrocephalus can also occur, especially in the presence of a type II Chiari malformation.

9. Myelomeningocele A myelomeningocele often results in sensory and motor deficits that can be severe. Patients often have bowel and bladder dysfunction as well. In utero surgical repair of a myelomeningocele may reduce the incidence of associated hydrocephalus and improve overall neurologic function.

10. Conditions Associated with Spina Bifida Attention and Learning Difficulty Bladder Function Bowel Function Depression Epilepsy and Seizures Hip Displacement Hydrocephalus Latex Allergy Vision Lymphedema Obesity Pressure Injury Scoliosis Sleep Apnea Sexual Function and Infertility Tethered Spinal Cord  Weakness or Paralysis

11. Latex Allergy This is an extremely dangerous allergy to substances that contain latex. It is common in individuals with spina bifida. Latex allergy is a result of repeated exposure to latex, particularly in exposure to the mucous membranes. Some will develop a rash when latex touches their bodies, but many can develop severe breathing issues from inhaling latex dust and odor.

12. Latex Allergy Avoidance of latex products to reduce exposure is necessary. This includes many medical supplies and equipment (most are labeled as non-latex due to this severe allergy in many individuals), baby supplies like bottles, nipples and pacifiers, toys, latex balloons, and foods such as avocados, bananas, chestnuts, kiwi and passion fruit . Because latex allergy is so dangerous, parents and pediatric hospitals only allow mylar balloons.

13. Anesthetic Considerations: Latex sensitivity: so perioperative exposure to latex should be avoided. Avoidance of succinylcholine because of increased risk for hyperkalemia in the setting of motor deficits. Resistance to nondepolarizing muscle relaxants can occur in weak extremities, so titration of muscle relaxant dose should not be based on monitoring of the lower extremities. Be aware of other neurologic deficits that may be related to hydrocephalus, such as the presence of a CSF-diverting shunt or Chiari malformation.

14. Tethered Spinal Cord Syndrome During fetal development the vertebral column develops and elongates faster than the spinal cord. Abnormal attachments of the spinal cord to the vertebral column can result in stretching of the spinal cord and development of tethered spinal cord syndrome. These abnormal attachments can occur in the setting of myelomeningocele, dermal sinus tracts, lipomatous tissue in the spinal canal, diastematomyelia (a bifurcated spinal cord), or a filum terminale of reduced elasticity .

15. Tethered Spinal Cord Syndrome Also, trauma or injury to the spinal cord and vertebral column can cause scar formation that can lead to cord tethering. Spinal cord stretch leads to dysfunction. Depending on the cause and severity, tethered spinal cord syndrome can present at any stage of life from early childhood through adulthood. Many individuals with a tethered spinal cord have cutaneous manifestations overlying the anomaly, including tufts of hair, hyperpigmented areas, cutaneous lipomas, and skin dimples. Scoliosis and foot deformities such as clubfoot may also occur.

16. Tethered Spinal Cord Syndrome Spinal anesthesia in patients with a tethered spinal cord may increase the risk of cord injury. Normally the conus medullaris lies at the level of L1–L2 in adults. Patients with tethered spinal cord syndrome often have a conus medullaris that lies below the L2 level. There may also be stretch of the cord  without  a low conus medullaris , or there can be a functional cord stretch that may occur only with changes in position. Patients may present with motor and sensory deficits and bladder and bowel incontinence. Surgical management often involves release of tethering if possible.