Intimal Fibroplasia: An Unusual Etiology of Stroke

Robert A. Schwartz, MD, Camilo R. Gomez, MD, Syracuse, New York, and St . Louis, Missouri

Individuals with arterial intimal fibroplasia represent a rare subset of patients with proliferative disorders of the arterial wall. This case describes the successful antemortem management of intimal fibroplasia of the internal carotid artery which had caused ipsilateral cerebral infarction. The noninvasive and invasive imaging characteristics of the lesion are also described. (Ann Vasc Surg 1989;3:384-386)

KEY WORDS: lntimal fibroplasia; cerebral infarction; carotid artery.

Arterial fibrody splasia (arterial fibromuscular dysplasia) was first uniformly classified by Harrison and McCormack in 1971 [l]. Using their classifica- tion, other authors have estimated that intimal fibroplasia constitutes a rare subset of approxi- mately 5% of all the individuals with arterial fibro- dysplasia [2]. Review of the literature reveals a paucity of information on the clinical course and management of patients with intimal fibroplasia of their cervical carotid arteries. This case report illustrates the radiographic findings and successful management of a patient who experienced a stroke caused by intimal fibroplasia of the extracranial internal carotid artery.

CASE REPORT In March 1987, a 52-year-old woman was admitted for

evaluation of a stroke which involved predominately her right hand. A week earlier, the patient had noted the sudden onset of dysesthesia and partial paresis of the right hand which was followed by a generalized myoclonic-tonic seizure. Upon retrospective review, the patient related a history of numer-

From the Department of Surgery, State University of New York Health Science Center, Syracuse, New York, and the Department of Neurology, S t . Louis University Hospitals, St. Louis, Missouri. Reprint requests: Robert A . Schwartz, MD, Department of Surgery, SUNY Health Science Center, 750 East Adurns Street, Syracuse, New York 13210.

ous episodes of short duration right upper extremity dyses- thesia which had spontaneously occurred and remitted over the previous one year.

Physical exam revealed that the patient was awake and oriented, with intact attention, language, memory, and judg- ment. Motor examination of the right upper extremity dem- onstrated residual weakness of the wrist and hand flexor and extensor musculature. No other motor abnormalities were present. Sensory, cerebellar, and brain stem functions were normal. A loud left cervical bruit was noted.

A color Doppler ultrasound imaging examination dem- onstrated a smooth, hypoechoic mass in the bulb of the left internal carotid artery. The mass created a hemody- namically significant stenosis of the internal carotid artery (Fig. 1). There was no sonographic evidence of athero- sclerosis in any of the cervical carotid arteries.

Computerized tomography of the patient’s head re- vealed a left parietal cerebral infarction which enhanced with intravenous iodinated contrast (Fig. 2). CT images of the neck once again verified the presence of a mass in the left internal carotid artery bulb which caused a significant stenosis and was radiolucent with little internal structural architecture (Fig. 3). Selective contrast arteriography illustrated the smooth intraluminal mass without evidence of cerebrovascular atherosclerosis (Fig. 4).

The radiographic evidence derived from the diagnostic testing suggested that the mass in the left internal carotid artery represented soft material with a relatively high water content. Since this type of material when present in the arterial circulation may embolize, the patient under- went immediate exploration of her left cervical carotid arteries with local anesthesia. The patient tolerated ca- rotid cross-clamping without temporary shunting and the ulcerated mass was removed by dissection along with a

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Fig. 1. Color Doppler ultrasound image (sagittal view) of left carotid bulb showing near total luminal occlu- sion by hypoechogenic material (insert represents

rayscale enhancement). Pulse gated Doppler signal 9 rom area of stenosis also displayed.

naturally occumng cleavage plane (Fig. 5). The longitudinal arteriotomy was closed primarily. The patient’s postopera- tive course was uncomplicated. Pathologic examination of the specimen revealed histologic evidence of intimal fibro- plasia (Fig. 6). Secondary verification was also obtained by consultation with the Armed Forces Institute of Pathology. Color Doppler imaging six months after surgery showed no evidence of recurrence or restenosis.

DISCUSSION

Although intimal fibroplasia is classified as a subcat- egory of fibromuscular dysplasia, this case report sug-

Fig. 2. CT scan demonstrating enhancement of ln- farcted cerebral cortex by iodinated, intravenously administered contrast.

Fig. 3. CT scan of the cervical internal carotid artery showing radiolucent mass nearly occludlng lumen with intravenously administered iodinated contrast enhancement (arrows).

gests that the disease entity has a markedly different radiologic appearance. The ultrasonographic charac- teristics of fibromuscular dysplasia include increased echogenicity of the arterial muscularis with discernible thickening. In contradistinction, intimal fibroplasia in our patient presented as a hypoechogenic eccentric mass with a sonographic reflectivity similar to that of intraluminal thrombus. Similarly, computerized to- mography demonstrated the lesion to be radiolucent and eccentric.

Previous retrospective studies have documented the increased morbidity and mortality of operative inter- vention in cerebrovascular occlusive disease immedi- ately following stroke [3]. The intravascular lesion in our patient underwent degeneration and had ulcerated with a large quantity of recent thrombus in the ulcer bed. The thrombus fragmented easily as did the ulcer- ated intimal fibroplastic mass suggesting that the pa- tient was at signficant risk for recurrent embolization. Thus, in the patient who displays the triad of ultraso- nographic, Computerized tomographic, and arterio- graphic imaging evidence suggesting intimal fibroplasia as the etiology of stroke, surgical intervention appears to be the appropriate therapy. The gross appearance of the lesions with friability of the intimal tissue suggests that antiplatelet and anticoagulation therapy offers less protection against embolization than surgical extrica- tion.

The recurrence rate of restenosis or embolization after reconstruction of a carotid artery with intimal fibroplasia is unknown. This case report describes initial successful reconstruction by removal of the

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Fig. 4. Selective injection iodinated contrast arteriog- raphy of left cervical carotid arterles (2 views).

intraluminal mass along a naturally occurring cleav- age plane and primary closure. This choice of reconstruction was based on the surgeon’s percep- tion that the mass represented thrombus of cardiac origin without knowledge of its histologic character. Longitudinal follow-up of this patient as well as the reports of other cases will clarify the optimal method of reconstruction.

REFERENCES

1. HARRISON Jr EG, McCORMACK LJ. Pathologic classifi- cation of renal arterial disease in renovascular hypertension. Mayo Clin Proc 1971;46:161-167.

Fig. 6. Photomicrograph of intimal fibroplastic lesion demonstrating irregularly arranged mesenchymal cells underlying the dlsrupted endothelial surface of the area of ulceration (hemotoxylin-eosin, X 120).

2. LUSCHER TF, LIE JT, STANSON AW, HOUSER OW, HOLLIER LH, SHEPS SG. Arterial fibromuscular dyspla- sia. Mayo Clin Proc 1987;62:931-952.

3. McCOLLOUGH JL, MENTZER Jr RM, HARMEN PK, KAISER DL, KRON IL, CROSBY IK. Carotid endarterec- tomy after a completed stroke: reduction in long term neuro- logic deterioration. J Vasc Surg 1985;2:7-14.