Introdution

Encephalocele is a rare congenital condition in which the neural tube does not close and forms a sac-like bulge with brain tissue and spinal fluid that pokes through the skull. This neural tube defect can be seen in 1 in 5000 births worldwide. The improper closure of the cranial part of the neural tube results in a defect.^1,2

The size of an encephalocele varies from a few centimetres to a large swelling. When the size of an encephalocele exceeds the head size, it is termed a giant encephalocele.^1,2 Around 80 to 90 per cent of encephalocele cases are from the western hemisphere.

Encephalocele is a birth defect which is caused by many factors, including genetic or environmental factors. People with a family history of neural tube defects are most likely to suffer from encephalocele.²

Suwanwela and Suwanwela in 1972 classified encephalocele based on its location in the brain: there are occipital encephalocele, sincipital, intrafrontal encephalocele, convexity, and basal encephalocele. Around 75% of encephalocele cases are of the occipital type.³

In this article, we discuss the anaesthetic challenges and perioperative care in encephalocele. Anaesthetic challenges, such as airway management, newborn susceptibility to hypoxemia, complex size and site, and risk of hypothermia, are discussed.

Perioperative care has three distinct phases: preoperative care, intraoperative care, and postoperative care. 

In preoperative care, cardiovascular, respiratory, haematological and biochemical aspects are evaluated. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) are among the utilsed devices.

Intraoperative care, during surgery, the premature rupture of an encephalocele has to be prevented, and intraoperative fluid loss and blood loss should be managed along with the respiratory issues.

Postoperative care is also significant. post-operation, patients may face difficulties such as infection, sepsis, brain abscess, and seizure, which are crucial factors that affect the patient.⁴ So, preventative antiepileptic and antibacterial treatments are essential.⁴

Anesthetic challenges

1. Airway management

• When the patient is in a prone position (lying face down), it's very difficult to establish a secure airway⁵
• Maintaining a suitable position of a newborn on the operating theatre table during induction and securing afterwards is crucial⁴
• The presence of mass will make respiratory support a challenging task⁴
• Mask ventilation and endotracheal intubation will become difficult or not possible due to limited neck extension and inappropriate positioning⁴

2. Newborn susceptibility to hypoxemia

After the induction of general anaesthesia, the low functional residual capacity, high oxygen consumption, small closing capacity, and increased risk of airway collapse lead to early bradycardia and even cardiac arrest.⁴

3. Complex size and site

The complex site and size of encephalocele will lead to intracranial anomalies, intraoperative blood loss, and prolonged anaesthesia.⁵

4. Hypothermia risk

The sudden hypothermia risk will develop due to the autonomic dysfunction.⁵

Perioperative care

In perioperative care, there are three distinct phases in patient management and surgical procedure:

1. Preoperative care
2. Intraoperative care
3. Postoperative care

1. Preoperative care

• Preoperative care includes the examination of the cardiovascular and respiratory systems of a patient⁴
• Preoperative haematological and biochemical tests are also done⁴
• Before surgery, the baby should be fasted for breast milk, and maintenance fluids should be given⁴
• Magnetic resonance imaging (MRI) has to be done before surgery to recognise the bone defect, the location of the sac, and the contents present in it. Doctors prefer a brain MRI because the patient will not be exposed to any ionising radiation²
• Before surgery, an MRI and an MRA (magnetic resonance angiography) scan should be thoroughly evaluated to minimise the damage to the blood vessels that supply the sac to feed the brain parenchyma²

2. Intraoperative care

• Anesthesiologist must take care of an encephalocele to prevent its premature rupture⁵
• The operative procedure also involves managing probable loss of an abundant volume of cerebrospinal fluid (CSF), which leads to an imbalance in electrolytes⁵ 
• During encephalocele surgery, dysfunction of autonomic control may lead to the sudden development of hypothermia. So, immediate consideration and management should be given to hypothermia, blood loss, and other related complications⁵ 
• Blood transfusion harms newborns. Maintaining minimal blood loss is crucial during surgery⁴ 
• During the surgery of a large encephalocele, blood loss may occur behind the dura mater, which leads to hemodynamic instability. In that case, estimating the blood loss and replacing it with warm fluid, blood, along with a vasopressor, will help maintain stable hemodynamics⁴ 
• Management of respiratory complications during surgery is also important⁴
• The patients with neural tube defects (NTDs) are commonly allergic to latex, with a reaction that may lead to intraoperative bronchospasm (tightening of the airways) or sudden cardiorespiratory arrest. So the masks, gloves, etc, should be free from latex⁴
• The newborn with multiple NTDs has a significant risk of hypothermia; thus, the ambient operating theatre temperature should be maintained at around 27 degrees Celsius. Administering warmed blood and fluid is also important.⁴ The extremities should be covered with a cotton blanket, and heated, humidified gases should be used. Intraoperative temperature should be monitored continuously⁴

3. Postoperative care

• Postoperative care is critical because postoperative outcomes such as wound infection, sepsis, brain abscess, and seizures are the crucial factors that affect the patient. So, prophylactic antiepileptic and antibacterial treatment are essential⁴
• In some patients, postoperative complications such as cardiac arrest, apnea, CSF leak, hypothermia, and raised intracranial pressure (ICP) may arise, so this should be managed carefully¹

FAQs

What is encephalocele?

Encephalocele is a rare congenital condition where the neural tube does not close, causing a sac-like bulge with brain tissue and spinal fluid that pokes through the skull.

What is a giant encephalocele?

When the size of an encephalocele is larger than the head, it's termed as a giant encephalocele.

What scans should be done before surgery? Why?

Magnetic resonance imaging (MRI) and Magnetic Resonance Angiography (MRA) are usually done. These scans are conducted to identify the bone defect, the location of the sac, and the contents present in it.

Why do doctors prefer an MRI scan?

Doctors prefer an MRI scan because it does not expose the patient to any harmful radiation.

What precautions should be taken for patients who are born with multiple Neural Tube Defects (NTDs)?

The newborn with multiple NTDs has a risk of hypothermia, so the operating theatre temperature should be maintained at 27 degrees Celsius, and warmed mattresses should be used. Additionally, administering warm blood and fluid is important; extremities should be covered with cotton blankets, and the intraoperative temperature should be monitored continuously.

Why should latex-free masks and gloves be used during surgery?

Latex-free masks and gloves should be used during surgery because patients with neural tube defects are commonly allergic to latex, which may lead to intraoperative bronchospasm (tightening of the airways) or sudden cardiorespiratory arrest.

Why is postoperative care critical?

Postoperative complications such as cardiac arrest, apnea, CSF leak, hypothermia, and raised intracranial pressure (ICP) may arise, so postoperative care is critical.

What challenges are faced by the anaesthetist during surgery?

Airway management, newborn susceptibility to hypoxemia, complex size and site, and hypothermia risk are challenges faced by the anaesthetist.

Summary

Encephalocele is a rare congenital condition (one in 5,000 newborns) in which the neural tube remains open, causing a sac-like bulge outside brain tissue and spinal fluid that pokes through the skull. It may be caused by factors such as genetic or environmental factors. In the Western Hemisphere, around 80 to 90 per cent of cases have been identified as occipital encephaloceles. Based on its location, there are occipital encephalocele, sincipital encephalocele, intrafrontal encephalocele, convexity, and basal encephalocele. In the above text, we have discussed related anaesthetic challenges and perioperative care. In perioperative care, there are three phases: preoperative care, intraoperative care, and postoperative care.