Case Report J Clin Ultrasound 14:732-734, November/December 1986

Carotid Artery Aneurysm Diagnosed by Duplex Scanning

David Rosenthal, MD, Robert G. Ellison, Jr, MD, Michael D. Clark, MD, Pano A. Lamis, MD, and Bruce R. Nilsen, RTR, RDMS

Aneurysms of the extracranial carotid arteries are rare, and reports of traumatic aneurysms from blunt trauma are anectodal.

An aneurysm of the high extracranial internal carotid artery presents a special problem not only in repair, because of the inaccessibility of the dis- tal artery, but in diagnosis as well. We believe this to be the first reported case of a posttraumatic

From the Department of Vascular Surgery, Georgia Baptist Medical Center, Medical College of Georgia, Atlanta, Georgia. For reprints contact David Rosenthal, MD, 315 Boulevard NE, Suite 412, Atlanta, Georgia 30312.

extracranial internal carotid artery aneurysm di- agnosed by duplex sonography.

CASE REPORT

A 63-year-old white female presented to her phy- sician with an “uncomfortable” left neck mass of 2 months’ duration. Pertinent past history in- cluded an automobile accident “whiplash injury approximately 20 years earlier, for which the pa- tient had been hospitalized. The patient’s physi- cian believed the mass was “metastatic lymph nodes overlying the carotid artery” and wished to biopsy it. Serendipitously, he referred the patient for EN” consultation; the consultant felt the mass was pul-

FIGURE l. Duplex scan demonstrating 2.8-cm internal carotid artery aneurysm (arrows) (CCA, common ca- rotid; ECA, external carotid; ICA, internal carotid; JV, jugular vein).

732 Q 1986 by John Wiley 81 Sons, Inc. 0091 -2751/86/090732-03 $04.00

CAROTID ARTERY ANEURYSM 733

flGURE 2. Computed tomographic scan of the neck demonstrating anatomic relationships of carotid aneurysm (arrows).

satile and referred the patient for vascular as- sessmen t .

On physical examination a gently pulsatile, nontender mass was appreciated at the edge of the angle of the mandible. A duplex scan (Tech- nicare Auto D Scanner) using a 7.5-MHz imaging probe with simultaneous 4.5-MHz Doppler spec- tral analysis was performed. A normal common carotid artery was imaged in the transverse and longitudinal planes, and a normal duplex spec- trogram was obtained. At the level of the internal carotid, a cystic mass was imaged, and pulsed Doppler assessment was performed to determine flow characteristics. A “dampened internal-like” flow pattern was recorded on spectral analysis. In view of these findings, the cystic mass was felt to represent an aneurysm of the internal carotid ar- tery, which measured 2.8 cm in diameter (Fig. 1). Cervical CT scans confirmed the dimensions and extent of the aneurysm (Fig. 21, and arteriography verified the extra- and intracranial anatomic re- lationships (Fig. 3). It was of interest to note that the arch, contralateral carotid, and vertebral ar- teries had no evidence of atherosclerotic occlusive or aneurysmal disease.

Under general anesthesia with continuous EEG surveillance, a n aneurysmectomy with ligation of the external carotid artery and saphenous vein interposition graft was performed. Prior to dis- charge a postoperative digital intravenous arte- riogram demonstrated patency of the saphenous vein interposition graft (Fig. 4). VOL. 14, NO. 9, NOVEMBERlDECEMBER 1986

FIGURE 3. Selective carotid arteriograms. Note tortuosity of internal carotid artery.

COMMENT

The bifurcation of the common carotid artery is the most frequently reported site of primary an- eurysm formation in the extracranial carotid sys- tem. There are several causes of extracranial an- eurysm formation, including atherosclerosis, syphilis, and local infection. These were the most common etiologic factors 50 years ago, but today trauma and previous carotid surgery cause the majority of extracranial carotid aneurysms.’ In fact, extracranial aneurysms of the high cervical internal carotid artery caused by blunt trauma are now the most frequently encountered aneu- rysms of the carotid distribution.2

Although patients with a carotid artery aneu- rysm usually present with a pulsatile mass in the cervical region, in many cases the mass has been unfortunately biopsied as a metastatic lesion, pro- ducing alarming h e m ~ r r h a g e . ~ Some aneurysms with pharyngeal presentation have been incised as peritonsillar abscesses with fatal result^.^

In patients with a history of “whiplash” injury, hyperextension and rotation of the neck may cause compression of the internal carotid artery against

734 CASE REPORT ROSENTHAL ET AL.

flGURE 4. Postoperative DIVA demonstrating patent saphenous vein interposition graft (arrow).

the transverse process of the atlas, and an intimal fracture may ultimately result in aneurysm for- mation.* These aneurysms tend to be fusiform rather than saccular in appearance.'

Ultrasonic duplex sonography and spectral analysis, with its high degree of sensitivity for the demonstration of carotid bifurcation pathology, is the noninvasive diagnostic screening test of choice. The only limitation of ultrasonic duplex sonog- raphy is in delineating the cephalad extent of a high cervical internal carotid artery aneurysm where i t passes beneath the mandible. As expe- rience continues to accumulate, the differentia- tion among carotid tortuosity, chemodectomy, and the rare primary carotid artery aneurysm will be- come more precise. We believe this to be the first

report of a posttraumatic carotid artery aneurysm diagnosed by duplex scanning.

REFERENCES

1. Goldstone J: Aneurysms of the extracranial carotid artery, in Rutherford RB (ed): Vascular Surgery (ed 2). Philadelphia, WB Saunders, 1984.

2. Rhodes EL, Stanley JC, Hoffman GL, et al: Aneu- rysms of extracranial carotid arteries. Arch Surg 11 1:339, 1976.

3. Weissman B, Rankow R Traumatic aneurysms of the carotid artery. Arch Otol88:543, 1968.

4. Wiaslow N: Extracranial aneurysms of the internal carotid artery. Arch Surg 13:689, 1926.

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