Case 18: "carotid" bruit

posted: April 20, 1997

Resident: Ian Angel, MD
Attending: John Connors, MD (neuroradiology) and Deepak Awasthi, MD (neurosurgery)

CLINICAL PRESENTATION: This 55 year old black woman was referred to the neurosurgery clinic by an internist for evaluation of an "asymptomatic carotid bruit". Patient describes about 3-4 month history of progressive malaise and multiple episodes of dizziness and "nearly passing out". She denies any visual changes, focal weakness or sensory changes (except those associated with removal of right ulnar nerve tumor- most likely a neurofibroma). Patient also denies any history of seizures, swallowing difficulty, hoarseness, hearing changes, tinnitus, transient neurological symptoms, difficulty walking. Patient does have mild global headaches, but no nausea or vomiting, no neck pain or stiffness.
Patient's past medical history is significant for neurofibromatosis, pheochromocytoma (resected once- without recurrence), hypertension. She denies diabetes mellitus, heart disease, cigarette smoking, lung or other GI disease.

EXAMINATION: Vital signs: pulse- 75; blood pressure- 185/90; RR-20; temp- 99. Patient is in good general medical condition. She is awake and alert and in no apparent distress.
There are multiple small "skin tags or neurfibromas" throughout her body including face. Also noticeable are cafe au lait spots.
Auscultation of the neck elicits a very loud bruit in the region of the left carotid. There is mild decrease in sensation in the right medial (ulnar) aspect of the hand. There are no other focal sensory deficits.
Good strength bilaterallly. No ataxia or dysmetria. Reflexes are normal and symmetric. No pathological reflexes.
Remainder of the exam was normal.

What is your differential diagnosis? What steps would you take at this time- diagnostic studies?

Please comment: dawast@lsuhsc.edu

DIAGNOSTIC STUDIES: Two conflicting doppler studies of the carotid vessels were performed- one study revealed miminal stenosis of the left cervical ICA, while the other revealed a moderate-high grade stenosis of the left cervical ICA. This led to a cerebral angiogram. Select vertebral films are shown below:

Left: right AP vertebral injection showing a large dural arteriovenous fistula (AVF) with vertebrobasilar steal into the origin of this AVF on the left. Right: left lateral vertebral injection revealing the orgin of the large dural AVF from the left VA without any distal filling of this VA from the left. Of note: both carotid vessels (cervical ICA) revealed no significant stenosis.

Thus, we were faced with a high flow dural AVF being supplied from the left VA and also "stealing" blood from the right VA. In retrospect, the patient was probably describing symptoms of vertebrobasilar insufficiency.

How would you proceed at this time- endovascular v. surgical v. conservative?

Please comment: dawast@lsuhsc.edu

STEPS TAKEN AT LSU: We felt that this fistula was symptomatic and thus needed to be obliterarted. The AVF was between the left VA and the paravertebral venous plexus. It was decided, in concert with our interventional neuroradiology team, to approach this endovascularly. An attempt was made to navigate a balloon from the right VA into the proximal part of the AVF in the left VA. This was not successful because of the tortousity of the vertebrobasilar junction. Next, an attempt was made to guide a balloon from the left VA into the distal part of the AVF. The balloon could not close the fistula. Thus, multiple coils were deployed into the fistula along with occluding the distal left VA (near the origin of the fistula). This significantly reduced the fistula- but another right VA injection still revealed filling of this fistula- see below:

Right VA AP projection. Note the persistent filling of the AVF from the right. There is no filling from the left VA.

A catheter could not be guided through the left VA and, as mentioned above, we could not navigate a balloon from the right VA.

How would you proceed at this time?

Please comment: dawast@lsuhsc.edu

We decided to enter the fistula percutaneously (under fluroscopic guidance)- see below:

Note the guide wire entering the dural AVF from a percutaneous route in the neck.

At this point, more coils were deployed into the fistula near its persistent inflow from the right VA into the proximal left VA. This completely eleiminated the dural AVF and significantly improved the caliber of basilar artery as well- see below:

Post-embolization right VA AP projection showing complete elimination of the dural AVF.

POSTOPERATIVE COURSE: Patient did very well postoperatively. She had no focal neurological deficits and discharged 1 day after embolization in satisfactory condition.

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