Keywords cerebral aneurysm - hypertension - Takayasu arteritis
Introduction
Takayasu arteritis (TA) is a large vessel vasculitis.[1 ] Anesthesia for patients with TA is challenging due to severe hypertension and its
effect on end-organs, vascular narrowing affecting distal circulation, and difficulties
faced in arterial blood pressure monitoring. Twenty percent of TA cases present with
central nervous system involvement, but intracranial aneurysms in patients with TA
is rare. We describe anesthetic management of an adolescent female suffering from
incidentally detected type IV TA and multiple cerebral aneurysms scheduled for aneurysmal
neck clipping following subarachnoid hemorrhage (SAH).
Case Report
A 16-year-old female patient weighing 42 kg presented to our tertiary care hospital
with complaints of sudden onset severe headache and vomiting followed by loss of consciousness
for 3 hours. It was not associated with fever, seizure, or any trauma. She had suffered
an episode of cerebrovascular accident at 8 years of age. On admission, her Glasgow
Coma Score (GCS) was E2V2M5, pulse rate 66/min, noninvasive blood pressure (NIBP)
in right arm 210/116 mm Hg, and respiratory rate 16/min, and bilateral pupils were
3 mm and equally reacting to light. Post resuscitation, her GCS improved to 15/15.
The patient was then shifted for emergency noncontrast computed tomography (NCCT)
brain, which revealed SAH. Urgent CT angiography of cerebral vessels was planned,
which demonstrated left internal carotid artery (ICA) bifurcation aneurysm measuring
4.2 × 3.7 mm (neck 4 mm) and right communicating segment ICA aneurysm measuring 2.3
× 2.6 mm (neck 2.5 mm) ([Fig. 1 ]) along with diffuse marked vasospasm. Hence, patient was posted for emergency craniotomy
for aneurysmal neck clipping. Her preoperative blood investigations were within normal
limits. Electrocardiograph showed left ventricular hypertrophy (LVH) with voltage
criteria.
Fig. 1 Left ICA bifurcation aneurysm measuring 4.2 × 3.7 mm (neck 4 mm) and right communicating
segment ICA aneurysm measuring 2.3 × 2.6 mm (neck 2.5 mm). ICA, internal carotid artery.
Preoperative NIBP in the right and left arms in supine position were 240/120 and 250/122
mm Hg, respectively. To our surprise, NIBP readings in the right and left lower limb
(LL) were 90/60 and 94/62 mm Hg, respectively. As the possibility of coarctation of
aorta (descending aorta narrowing) was raised, cardiology consultation was sought.
We had suspected coarctation of aorta in this patient because of young age, multiple
aneurysms, and discrepancy in lower and upper limb blood pressure. Limited transthoracic
echocardiography was done in preoperative period, which showed presence of LVH. Keeping
in mind emergent nature of surgery, it was decided to proceed for emergency clipping
with the goals of maintaining cerebral hemodynamics, reducing intracranial pressure,
and keeping lower limb mean BP of at least 70 mm Hg to avoid spinal cord ischemia.
In the operation theater, preinduction left radial artery was cannulated under local
anesthesia for invasive BP monitoring, while BP in the right LL was monitored noninvasively.
After preoxygenation, general anesthesia was induced with intravenous morphine 6 mg
and propofol titrated to loss of verbal contact. Muscle relaxation was achieved using
vecuronium 4 mg. Stress response of laryngoscopy and intubation was suppressed using
bolus doses of intravenous esmolol. Right subclavian venous cannulation was done for
central venous pressure (CVP) monitoring. Pin response was prevented by local pin
site infiltration of injection of Xylocard. BP changes during skin incision, craniotomy,
bone flap removal, and throughout the surgery were managed by titrated injection of
nitroglycerine infusion. Anesthesia was maintained with a mixture of oxygen (50%)
and nitrous oxide (50%) along with propofol infusion titrated to bispectral index
(BIS) of 40 to 60 and intermittent boluses of vecuronium. Intraoperatively, her upper
and lower limbs mean BP readings were targeted to 110 mm Hg and 70 mm Hg, respectively.
Intraoperative period was uneventful, and both the aneurysms were clipped successfully.
Postoperatively, the patient was monitored and was mechanically ventilated in neurosurgical
intensive care unit in view of intraoperative brain swelling. Bedside transthoracic
echocardiography was performed, which showed concentric LVH and normal left ventricular
systolic function. CT angiography of thorax displayed concentric circumferential mural
thickening with calcification involving distal arch, descending thoracic, and abdominal
aorta (TA type IV: chronic phase) ([Fig. 2 ]). She was started on multidrug oral antihypertensive therapy including telmisartan,
amlodipine, prazosin, and clonidine.
Fig. 2 The CT-angiography of thorax displayed concentric circumferential mural thickening
with calcification involving distal arch, descending thoracic and abdominal aorta
(TA type IV: chronic phase). Upper arrow: irregularities in outline and thickened
wall of descending thoracic aorta. Middle arrow: mural thickening with severe stenosis
proximal to origin of celiac artery. Lower arrow: mild mural thickening and narrowing
involving infra renal aorta. CT, computed tomography; TA, Takayasu's arteritis.
On postoperative day (POD) 3, the patient developed delayed ischemic neurologic deficits
for which NCCT of the head was done, which showed left middle cerebral artery territory
infarct. She was tracheostomized in view of prolonged mechanical ventilation. The
patient was discharged on POD14 with GCS of E4VTM6, right hemiplegia, and stable hemodynamics.
On 3-month postoperative follow-up, she was conscious and oriented with no sensory
or motor deficit.
Discussion
Takayasu's arteritis was first described by an Italian pathologist Gian Bathista Morgagni
in 1761.[2 ] Takayasu disease was first described in 1908 by a Japanese ophthalmologist, Takayasu.
The incidence of TA was found to be 2.6 new cases/million/year in the United States.[3 ] Females are predominantly affected, with the overall incidence being 85% of all
affected. The disease has multiple etiological factors, such as tuberculosis, syphilis,
streptococcal infection, rheumatic fever, collagen vascular disease, genetic factors,
and hypersensitivity.
Takayasu's arteritis is graded on the presence of four major complications: hypertension,
retinopathy, aneurysm formation, and aortic regurgitation.[4 ] Our patient belonged to stage III as per Ishikawa's grading. Based on angiographic
classification of TA, index case had stage IV disease.[5 ] Unlike other types of TA, type IV TA has feeble pulse in lower limbs, while pulse
can be felt in upper limbs. This accidental finding in our patient led to modifications
in hemodynamic goals (target mean BP) and monitoring (BP recordings in both upper
and lower limbs, application of pulse oximetry in the lower limb).
Avoidance of hypertension is of paramount importance while managing such cases. Wide
swings in BP can occur during craniotomy due to laryngoscopy, endotracheal intubation,
pin insertion, skin incision, and dural opening. These surges may result in rupture
of cerebral aneurysms, which were prevented in the index case by managing BP (using
antihypertensive agents) and maintaining adequate depth of anesthesia.
Prevention of hypotension is equally crucial for end-organ protection. Cerebrovascular
ischemia occurs in about one-third of these patients; hence, maintenance of cerebral
perfusion pressure is of utmost importance. We recorded BP from both the upper and
lower limbs during the perioperative period. The lower limb BP was considered significant
to identify the spinal cord ischemia in our patient having suspected coarctation in
descending aorta (later found to have TA type IV). We maintained target mean BP of
at least 70 mm Hg as it was baseline mean BP in lower limbs. Similarly, lower limb
was used for pulse oximetry monitoring for early identification of ischemia. CVP and
systolic pressure variation measurements provided adequate information about cardiac
preload and fluid status in our patient during the intraoperative period.
In addition to these considerations, patients with TA should be evaluated for clinical
features suggestive of carotid involvement, such as dizziness and syncope on head
extension and carotid bruit during preoperative visit. It is advisable to keep the
head in a neutral position avoiding hyperextension of the head during laryngoscopy,
which can lead to postoperative visual disturbances, vertigo, hemiparesis, and seizures.
Conclusion
To conclude, patients having multiple aneurysms should be suspected for presence of
vasculitis such as TA. Meticulous execution of predetermined anesthesia plans and
vigilant perioperative monitoring is warranted for the delivery of safe anesthesia
in these patients.
