A 45-year-old woman with a history of depression and headaches presented after an MRI examination raised the question of a possible pseudoaneurysm of the right internal carotid artery. She had no history of significant trauma to the neck or elsewhere, and no history of hypertension. On physical examination, the patient was alert and oriented. She had full strength and sensation in all four extremities.
A 45-year-old woman with a history of depression and headaches
presented after an MRI examination raised the question of a
possible pseudoaneurysm of the right internal carotid artery. She
had no history of significant trauma to the neck or else-where, and
no history of hypertension. On physical examination, the patient
was alert and oriented. She had full strength and sensation in all
four extremities. Her cranial nerve examination was remarkable for
unequal pupils, the right pupil being approximately 2 mm smaller
than the left; however, both pupils were reactive. The patient had
not recognized her own pupillary asymmetry and therefore could not
establish a date at which this finding may have occurred. Her
neurologic examination was otherwise within normal limits. What is
the most likely diagnosis?
A common carotid artery injection demonstrates a high cervical
internal carotid artery pseudoaneurysm measuring approximately
11×5 mm with a 5-mm neck.
A Palmaz-Schatz stent on a 3.4 microcatheter positioned across
the neck of the pseudoaneurysm.
This radiograph demonstrates the stent deployed in the internal
This common carotid artery arteriogram demonstrates the
appearance poststenting and coil placement.
A cerebral arteriogram revealed that the patient had a
moderately wide-necked pseudoaneurysm arising from the distal
cervical internal carotid artery, quite possibly resulting from an
unrecognized dissection secondary to fibromuscular dysplasia (FMD).
The aneurysm measured approximately 11×5 mm with a 5-mm neck
The patient was admitted to the hospital under the
interventional neuroradiology service, and vascular surgery and
neurosurgery were consulted. The treatment team agreed that a
surgical approach to the pseudoaneurysm would be a challenge
because distal control of the high cervical internal carotid artery
would be difficult. The cerebral arteriogram revealed no other
abnormalities. The patient had good collaterals, with a moderately
large right posterior communicating artery and a patent anterior
communicating artery visualized.
The patient was taken to the angio suite and, under neuroleptic
anesthesia, a 7-F sheath was placed in the right common carotid
artery. Repeat cerebral arteriography was performed with Visipaque
(iodixanol 270mgI\mL, Nycomed Amersham, Princeton, NJ). Because of
the patient's FMD and the high location of the lesion, the team was
reluctant to try to place a Wallstent. Consequently, a 4×15 mm
Palmaz-Schatz Crown balloonexpandable stent on a 3.5-F
microcatheter was advanced across the neck of the aneurysm and
deployed (figures 2,3). A control angiogram demonstrated that the
stent was in proper location; however, there was significant
residual filling of the aneurysm. Consequently, a Prowler 10
microcatheter (Cordis Endovascular, Miami, FL) was advanced through
the stent into the aneurysm. Four GDC coils were placed in the
aneurysm (figure 4). A final control angiogram demonstrated a small
amount of residual neck remnant. No further coils were placed
because of a concern for the possibility of extrinsic compression
of the stent from the coils.
The patient tolerated the procedure well, without neurologic
compromise at the end of the procedure. She had an uneventful
postoperative course, and was discharged two days
Fibromuscular dysplasia is a vasculopathy of unknown etiology
that affects the renal arteries, the internal carotid arteries, and
the vertebral arteries. SUP>>1A characteristic "string of
beads" appearance usually is seen in the mid-cervical internal
carotid artery. The internal carotid artery is affected in
approximately three-fourths of all cases; the vertebral artery is
involved in 15 to 25%.
Dissection is a well known complication of FMD; pseudoaneurysm
formation is an unusual secondary finding. Patients with FMD also
are subjected to an increased risk of intracranial aneurysms.
S imilar cases of internal carotid artery pseudoaneurysms treated
with coils and stents have previously been reported.
This case was somewhat unusual, as the aneurysm was able to be
found and the patient had been asymptomatic at presentation. In
this case, the use of a small, balloon-expandable stent catheter
made for a very safe and low profile means of placing the
This case demonstrates that new, low profile flexible stents can
be quite useful in treating surgically difficult-to- access
vessels. The combination of stents and coils can be quite
effective, providing a low risk, non-invasive means of treating
arterial dissections and pseudoaneurysms.
Prepared by John S. Sarzier, MD; Bruce Zweibel, MD; Avery J.
Evans, MD, Radiology Associates of Tampa, Tampa, FL.