Neurosurgical interventions in pregnancy pose a dual challenge of optimizing cerebral
physiology without compromising fetal well-being. Intracranial pressure lowering strategies,
such as mannitol or furosemide administration, may have an adverse effect on the fetus.
More importantly, gestational hypertension or eclampsia may mimic the features of
intracranial pathology and compromise the management. Here, we describe the perioperative
management of a pregnant female posted for awake craniotomy (AC) and excision for
intracranial space occupying lesion at 22 weeks of gestation with a special emphasis
on selection of perioperative medications.
A 26-year-old right-handed female was presented in emergency room with new onset of
seizures. Magnetic resonance imaging brain described a space-occupying lesion in the
left temporal region (3 × 2.5 × 4 cm near Wernicke area's area [Fig. 1A ]) for which AC with cortical mapping and tractography was planned in lateral position
([Fig. 1B ]). Her preoperative workup was acceptable, and there were no neurological deficits.
The psychological preparation of the patient was done using standard protocol for
AC in addition to explaining the benefits of avoiding the exposure of fetus to the
anesthetic agents. The potential risks related to AC and the possibility of adverse
maternal and fetal outcomes were also explained. Standard American Society of Anesthesiologists
(ASA) guidelines for fasting were followed. Premedication included antiepileptics,
aspiration prophylaxis (tab. ranitidine 150 mg and metoclopramide 10 mg) the night
prior and on the day of surgery, and inj. progesterone (Proluton Depot 250 mg intramuscular)
for tocolysis. Intraoperative monitoring included standard ASA monitors, invasive
arterial blood pressure, and continuous cardiotocography. We planned the awake-awake-awake
technique. Infusion dexmedetomidine was started at 0.5 µg/kg/h to target Ramsay sedation
score 2, which was stopped before the dural opening. Scalp block was given with 2%
lignocaine adrenaline (1:2,00,000) and 0.25% bupivacaine, 15 mL each (total volume:
30 mL). After scalp block, head was fixed with Sugita four pin head holder. Absence
of pin response indicated the adequacy of scalp block. The needle electrodes were
placed to record the motor-evoked potentials on both right-sided upper and lower limbs.
The voltage was kept minimum to elicit the response during motor mapping as higher
voltages can incite hypercontraction of the gravid uterus.[1 ] Language testing was done by stimulation of the language area while continuously
communicating with the patient for the components of fluency and comprehension. The
patient was calm, conscious, and cooperative throughout the procedure and maintained
stable hemodynamics. Intraoperative medications included cefuroxime 1.5 g, ondansetron
4 mg, levetiracetam 1 g, and paracetamol 1 gm. The intraoperative course was uneventful.
Postoperatively, there was no deficit in the mother and a healthy baby was delivered
vaginally at 40 weeks gestational age.
Fig. 1 (A ) T2-weighted magnetic resonance imaging in coronal section showing hyperintense lesion
(black arrow) along the left inferior temporal location with mild gyral expansion.
(B ) Intraoperative position of the patient in lateral decubitus.
AC is preferred for lesions near eloquent areas and in high-risk patients. There is
very limited data in the form of isolated case reports or case series related to AC
in pregnant females. AC has a dual advantage of real-time neurological monitoring
and avoiding exposure of anesthetic agents to the developing fetus.[2 ]
There are a few challenges during AC in pregnant patients, which needs to be considered
during surgery. Antiedema drugs, such as mannitol, cross the placenta and may cause
fetal dehydration.[3 ]
[4 ] However, it had been safely used during pregnancy but in a smaller dosage, up to
0.5 g/kg. Dexamethasone is routinely given in intracranial space-occupying lesions
to reduce perilesional edema. In addition, it helps in fetal lung maturation and reduces
nausea and vomiting. Thus, it can be given safely to these patients.[5 ] These patients are at risk of excessive sedation due to internal endorphins release
and hormonal changes. We should give judicious sedation that too under strict monitoring.
Hence, we avoided loading dose of dexmedetomidine and other sedative analgesics.
We must be prepared for potential intraoperative complications too.[6 ] As antiepileptics have potential teratogenic effects, the drugs with minimal fetal
effects should be chosen. For intraoperative seizures, the management line includes
ice cold saline instillation in the surgical field followed by propofol boluses; if
not controlled, midazolam and levetiracetam should be used.[6 ] If seizures are uncontrolled, we should follow the status epilepticus protocol for
pregnant females.[7 ]
The hemodynamic target varies slightly from the nonpregnant patients, including maintaining
normotension (20% baseline), euvolemia, normoxia (partial pressure of oxygen > 80 mm Hg to avoid fetal hypoxia), normothermia, normocapnia in the early trimester,
and normoglycemia (110–150 mg/dL) should be considered.[8 ] Mild hyperventilation (28–32 mm Hg) may be continued to maintain physiological hyperventilation
in second and third trimester. It may not be possible to manipulate respiration in
awake patients, but deep sedation should be avoided to prevent respiratory depression.
Moderate-to-severe hyperventilation may reduce uterine blood flow. In advanced pregnancy,
left uterine displacement should be done to avoid aortocaval compression. The current
case was done in lateral position that displaced the uterus from aorta.
Pregnancy is a prothrombotic state that makes it deemed necessary to prescribe deep
vein thrombosis prophylaxis in patients with neurological deficits.[9 ] Mechanical thromboprophylaxis should be initiated in immediate postoperative period
in immobile patients. The pharmacological thromboprophylaxis may be started in high-risk
patients after 48 to 72 hours. The current case did not develop any deficit. Hence,
she was mobilized on the postoperative day 0.
Awake-awake-awake craniotomy with cortical mapping is safe for glioma resection in
pregnant females. The lateral position avoids aortocaval compression. Hemodynamic
and respiratory parameters should be targeted to strike the balance of cerebral and
fetal perfusion. Cerebral decongestants should be used with caution. A multidisciplinary
approach is required for keeping the mother and baby healthy.
