Spontaneous carotid dissection: Duplex scanning in diagnosis and management T o d d F. Early, MD, Roger T. Gregory, MD, Jock R. Wheeler, MD, Stanley O. Snyder, Jr., MD, Robert G. Gayle, MD, F. Noel Parent, III, MD, and Kathy Sorrell, R N , Norfolk, Va. The clinical, duplex, and angiographic findings in six patients with seven spontaneous
extracranial carotid artery dissections are reported. Four dissections resulted in internal carotid artery occlusion. These patients complained of ipsilateral headache followed by contralateral hemiplegia. The other three dissections involved the common carotid artery and resulted in dual (one true and one false) lumens. Two of these dissections were asymptomatic. All dissections were treated nonoperatively with anticoagulant therapy. Neurologic deficits improved or disappeared in all symptomatic patients. On follow-up studies, one of the four internal carotid occlusions completely resolved with normalization of the duplex examination. All three dual lumen dissections remained patent on serial studies. Diagnostic duplex characteristics, both conclusive and supportive, of carotid dissections are described. Duplex scanning is shown to be accurate in diagnosing and ideally suited for serially following spontaneous carotid dissections. (J VAse SuR~ 1991;14:391-7.)
Spontaneous carotid dissection is an uncommon but increasingly identified cause of cerebral ischemia. 13 Appropriate treatment requires early recognition with an accurate diagnosis. Carotid angiography has been the usual modality to obtain this diagnosis. Also, because of the frequently evolving nature of these lesions, serial arteriographic studies have been required to determine the outcome of the dissection. Several articles in the literature describe angiographic features of carotid dissections. 1'4"s Duplex imaging characteristics of spontaneous carotid dissections are described in this report. Duplex scanning is shown to be ideally suited for the initial evaluation and serial follow-up of carotid dissections. PATIENTS A N D M E T H O D S
From July 1987 through May 1990 six patients with seven spontaneous carotid artery dissections (bilateral in one patient) were admitted to the Vascular Surgery Division of the Eastern Virginia Graduate School of Medicine. The medical records of From the Divisionof VascularSurgery,EasternVirginia Graduate School of Medicine, Norfolk. Dr. Early is currently at the Universityof Tennessee,Memphis. Presented at the Fifteenth Annual Meeting of the Southern Association for Vascular Surgery, Palm Springs, Calif., Jan. 23-26, 1991. Reprint requests: Roger T. Gregory,MD, 250 W. Brambleton Ave., Suite 101, Norfolk, VA 23510.
24[6/30273
these patients were reviewed to determine presenting symptoms, carotid duplex and angiographic findings, treatment, complications, and outcome. Carotid arteriograms were available for review in five patients. The remaining patient was transferred from another hospital for follow-up, and only the angiographic report was available. All patients had initial bilateral duplex scans. Serial duplex studies were then obtained to determine the outcome of the dissection. Follow-up ranged from 2 to 38 months. Patients in the early years of the study were examined with gray-scale duplex scanning. When color-flow duplex scanning became available, this modality was applied as well. RESULTS Patient data including age, sex, symptoms, and treatment are shown on Table I. The group was made up of five men and one woman. Ages ranged from 35 to 89 years (mean, 55 years). Table II describes the duplex and angiographic findings. In five patients the duplex findings were confirmed by angiography. In one patient (no. 6), the duplex scan was interpreted as demonstrating a common carotid artery (CCA) dissection and an occlusion of the internal carotid artery (ICA). An arteriogram later the same day confirmed the CCA dissection but demonstrated a patent ICA. This most likely represents a false interpretation of the duplex scan; however, the possibility of resolution of the ICA occlusion during 391
392
Journal of VASCULAR SURGERY
Early et aI.
intramural thrombus
B
intimal flap
Fig. 1. A, Longitudinal duplex scan of an occluded internal carotid artery. The intima (white line) is seen overlying the intramural thrombus. B, Schematic drawing demonstrates the dissection.
Table I. Carotid dissection patient data Patient
Age~sex
Symptoms
1
35/F
2
40/M
3
46/M
4
44/M
Left eye amaurosis fugax and left occipital headache; 24 hours later, right hemiplegia and aphasia Right eye amaurosis fugax and right temporal headache followed by left arm weakness Left facial, ear pain and left headache; several days later developed aphasia and right hemiplegia Left hemiplegia
5
78/M
Left eye amaurosis fugax
6
89/M
Right hemiplegia and aphasia
ICAD, Internal carotid artery dissection; CCAD, common carotid artery dissection.
Diagnosis Left ICAD Right ICAD Left ICAD Right ICAD Left CCAD Right CCAD Left ICA stenosis Left CCAD
Volume 14 Number 3 September 1991
Duplex scanning of carotid dissections 393
Fig. 2. Longitudinal color-flow scan (black and white copy) shows a tapered occlusion of the distal internal carotid artery.
Fig. 3. Carotid angiogram demonstrates a tapered internal carotid artery occlusion.
Table II. Carotid duplex and angiogram results
Patient
Diagnosis
Duplex scan
Angiogram
1 2
Left ICAD Right ICAD
Left ICA occlusion Right ICA occlusion
3
Left ICAD
4
Right ICAD Left CCAD Right CCAD Left ICA stenosis
Left ICA occlusion, intimal flap overlying intramural thrombus Right ICA occlusion Left CCA DLD Right CCA DLD Left ICA stenosis
Left CCAD
Left CCA DLD and occluded left ICA
5 6
Left ICA occlusion Right IGA occlusion 2 cm distal to the carotid bifurcation Tapered IGA occlusion Angiogram report: occluded right ICA Right CCA DLD, 2 cm from origin to 2 cm proximal to the bifurcation; left ICA stenosis, greater than 90% Left CCA DLD and patent left ICA
ICAD, Internal carotid artery dissection; CCAD, common carotid artery dissection; DLD, dual lumen dissection.
the short time interval between studies could not be ruled out. Two patterns of carotid dissection were seen. Dissections resulting in total occlusion of the 1CA occurred in four patients. The other three were CCA dissections resulting in dual carotid lumens with one true and one false lumen. The clinical manifestation of the dissections varied depending on which disease pattern was seen. In the dissections resulting in 1CA occlusions, ipsilateral headache was the presenting
symptom with contralateral hemiparesis occurring several hours to several days later. In contrast, two of the three CCA dissections resulting in dual lumens were asymptomatic. One of these was discovered contralateral to an occluding ICA dissection, and the other was contralateral to a symptomatic ICA stenosis. It is interesting to note that the only symptomatic CCA dual lumen dissection was in the patient with the initial duplex interpretation of ICA occlusion with the arteriogram showing ICA patency.
Journal of VASCULAR SURGERY
394 Early et al.
Fig. 4. B-mode duplex image of the common carotid artery demonstrates the dissected intima (arrow) and distal reentry point.
Fig. 1 is a gray-scale image demonstrating a dissection resulting in an occluded ICA. Blood dissecting behind the proximal tear causes a tapered occlusion. The intimal flap is seen overlying the intramural thrombus. Fig. 2 is a black and white copy of a color-flow duplex scan of the same patient revealing proximal patency with a distal occlusion. Fig. 3 is the arteriogram of this patient once again demonstrating the characteristic tapering occlusion of the ICA distal to the carotid sinus. Fig. 4 is an example of a dissection resulting in dual lumens. This gray-scale image shows the CCA with an intimal flap and the distal reentry point of the dissection proximal to the carotid bifurcation. Fig. 5, _A is a color-flow image of this patient demonstrating flow through both lumens. Different flow velocity in each lumen is depicted by different color intensity. Fig. 5, B is a cross-sectional view again showing the intimal flap with flow in the true and false lumen. Fig. 6 is the angiogram of this patient confirming the CCA dissection. Spectral analysis of the Doppler signal in these patients with dual lumens also demonstrated different flow velocities in each lumen. Serial follow-up duplex examinations were obtained on all patients. In all three patients with
dissections resulting in dual lumens, both lumens remained patent. Three of the four ICA occlusions remained occluded on follow-up scans. One patient (no. 1) had resolution of her occlusion with complete restoration of flow in the ICA with no evidence of an abnormality on follow-up duplex scanning. All carotid dissections were treated nonoperatively. Five patients were treated with initial heparin sodium therapy followed by conversion to oral warfarin for long-term anticoagulation. In the remaining patient a symptomatic ICA stenosis, contralateral to a spontaneous dissection, was treated with carotid endarterectomy followed by postoperative warfarin therapy. No complications as a result of anticoagulation developed in any patients. Both patients with asymptomatic CCA dissections remained asymptomatic during the follow-up period. All patients with symptoms from their carotid dissection had either complete resolution of symptoms or improvement with minimal residual neurologic deficit. DISCUSSION
The first case of spontaneous carotid artery dissection was reported by Jentzer in 1954. 6 A review of the literature in 1972 produced only 11 cases; five of these patients died of massive cerebral infarcts. 7 Carotid dissections were thought to be rare occurrences with poor outcome. With the increased use of carotid angiography to evaluate patients with cerebral ischemia, carotid dissections were reported more frequently. 1'2 Bogousslavsky et al.3 discovered carotid artery dissection in 2.5% of 1200 patients with a first stroke. Along with more frequent recognition of dissections, the typically less severe neurologic deficits resulting from carotid dissections were also realized, with several authors reporting complete resolution of dissections on serial arteriograms.3'8"10 Treatment in early reports included a variety of surgical procedures including external carotid artery to internal carotid artery bypass grafting, carotid ligation, carotid resection with vein graft interposition, thrombectomy, carotid endarterectomy, and superficial temporal to middle cerebral artery bypass grafting5 '9'~-13 These procedures produced varying success. With the recognition of less severe deficits and frequent complete resolution of symptoms, later series recommend nonoperative treatment with antiplatclet drugs or anticoagulation with serial arteriograms to monitor the response to therapy? -3'1+
Volume 14 Number 3 September 1991
Duplex scanning of carotid dissectiom 395
Fig. 5. Color-flow duplex scan of a common carotid artery dissection. L~t, Longitudinal view demonstrates different flow velocity in each lumen. Right, Transverse view demonstrates the common carotid artery (blue) dissection. Anticoagulation is proposed to reduce cerebral emboli and to prevent intraluminal and intramural clotting. Although angiography has been the standard for diagnosing and following carotid dissections, several other modalities have been described including ocular pneumoplethysmography, ''~ CT scanning, 16 magnetic resonance imaging, 17"I8 and duplex scanning. 3,~8,~9 Duplex scanning has several advantages over angiography. Duplex scanning can image the arterial lumen as well as the arterial wall to detect intramural thrombus. Both longitudinal and cross-sectional
views can be imaged. Duplex scanning can provide hemodynamic information regarding the severity of stenosis resulting from a dissection. Duplex scanning is noninvasive, less expensive than angiography, and can be performed on an inpatient or outpatient basis. Duplex scanning also has limitations. Since most dissections occur distal to the carotid bifurcation, imaging a high dissection may be impossible. Also, duplex scanning gives no information regarding intracerebral dissections or emboli. Therefore, angiography is required initially to detect intracerebral abnormalities. The pattern of carotid dissection in this series
396
lou~naaof VASCULAR SURGERY
Early et al.
serially observing patients with spontaneous carotid dissection. Table I I I lists duplex characteristics o f dissections. O u r current practice is to screen patients with suspected carotid dissection using duplex scanning. Those patients with evidence o f a dissection or other carotid abnormality u n d e r g o carotid a n g i o g r a p h y to confirm the diagnosis and determine the distal extent o f the dissection. T r e a t m e n t o f carotid dissection is controversial; no controlled study is available to determine the optimal therapy. O u r current practice is to initially anticoagulate these patients with intravenous heparin s o d i u m and follow this with longterm oral warfarin. Duplex scanning is then used to serially follow the response to anticoagulant therapy. REFERENCES
Fig. 6. Digital subtraction angiogram demonstrates a right common carotid artery dual lumen dissection.
T a b l e I I I . Duplex diagnostic characteristics o f carotid dissections Conclusive Two ICA or CCA lumens imaged, separated by an intimal flap Two separate ICA or CCA frequency curves on spectral analysis Stenotic carotid lumen with intima overlying intramural thrombus Tapered ICA occlusion with an intima! flap overlying occluding thrombus Supportive Long smoothly tapered ICA stenosis Occluded ICA in the presence of a typical clinical history ICA, Internal carotid artery; CCA, common carotid artery.
differs f r o m other reports. Dissections limited t o the C C A were seen in three patients. I n a recent review o f the literature, G r a h a m et al.2o f o t m d 264 cases o f spontaneous extracranial carotid artery dissections and reported only one case o f dissection limited to the CCA. A further review discovered only three other cases o f C C A dissection in the literature. 21'2~ T h e three cases in this report suggest that C C A dissection is n o t as rare as previously thought. This series o f patients demonstrates that duplex scanning is an accurate m e t h o d o f diagnosing and
1. Mokri B, Sun& TM Jr, Houser OW, Piepgras DG. Spontaneous dissection of the cervical internal carotid artery. Ann Neurol 1986;19:126-38. 2. Biller J, Hingtgen WL, Adams FIP Jr, Smoker WRK, Godersky JC, Toffol GL Cervieocephalic arterial dissections. A ten-year experience. Arch Neurol 1986;43:1234-8. 3. BogousslavskyJ, Despland PA, Regli F. Spontaneous carotid dissection with acute stroke. Arch Neurol 1987;44:137-40. 4. Fisher CM, Ojemann RG, Roberson GH. Spontaneous dissection of cervicocerebral arteries. Can J Neurol Sci 1978;5:9-19. 5. Houser OW, Mokri B, Sundt TM Jr, Baker HL Jr, Recse DF. Spontaneous cervical cephalic arterial dissection and its residuum: angiographic spectrum. AINR 1984;5:27-34. 6. Jentzer A. Dissecting aneurysm of the left internal carotid artery. Angiology 1954;5:232-4. 7. Ojemann RG, Fisher CM, Rich JC. Spontaneous dissecting aneurysm of the internal carotid artery. Stroke 1972;3:43440. 8. McNeill DH Jr, Dreisbach J, Marsden RJ. Spontaneous dissection of the internal carotid artery. Its conservative management with heparin sodium. Arch Neurol 1980;37: 54-5. 9. Pozzati E, Gaist G, Poppi M. Resolution of occlusion in spontaneously dissected carotid arteries. J Neurosurg 1982; 56:857-60. 10. Geeraert AJ, AI Saigh All. Spontaneous dissection of the carotid artery: an unusual cause of stroke in younger patients. Can Med Assoc J 1987;136:51-3. 11. Ehrenfeld WK, Wylie ES. Spontaneous dissection of the internal carotid artery. Arch Surg 1976;111:1294-301. 12. Roome NS, Aberfeld DC. Spontaneous dissecting aneurysm of the internal carotid artery. Arch Neurol 1977;34:251-2. 13. Miyamoto S, Kikuchi H, Karasawa J, Kuriyama Y. Surgical treatment for spontaneous carotid dissection with impending stroke. J Neurosurg 1984;61:382-6. 14. Hart RG, Easton JD. Dissections of cervical and cerebral arteries. Neurol Clin 1983;1:155-82. 15. Gee W, Kanpp HA, McDonald KM, Lin FZ, Curry JL. Spontaneous dissection of internal carotid arteries: spontaneous resolution documented by serial ocular pneumoplethysmography and angiography. Arch Surg 1980;115:944-9. 16. Petro GR, Witwer GA, Cacayorin ED, et al. Spontaneous
Volume 14 Number 3 September 1991
Duplex scanning of carotid dissections 397
dissection of the cervicalinternal carotid artery: correlation of arteriography, CT, and pathology. MR 1987;148:393-8. 17. Goldberg HI, Grossman R_I, Gomori JM, Asbury AK, Bilaniuk LT, Zimmerman RA. Cervical internal carotid artery dissecting hemorrhage: diagnosis using MR. Radiology 1986;158:157-61. 18. Rothrock IF, Lira V, Press G, Gosink B. Serial magnetic resonance and carotid duplex examinations in the management of carotid dissection. Neurology 1989;39:686-92. 19. Zirkie PK, Wheeler JR, Gregory RT, Snyder SO Jr, Gayle RG, Sorrell K. Carotid involvement in aortic dissection diagnosed by duplex scanning. J VAsc SURG 1984;1:700-3.
20. Graham JM, Miller T, Stinnert DM. Spontaneous dissection of the common carotid artcry. J VAsc SURG 1988;7: 811-3. 21. O'Dwyer JA, Moscow N, Trevor R, Ehrenfeld WK, Newton TH. Spontaneous dissection of the carotid artery. Radiology 1980;137:379-85. 22. Burklund CW. Spontaneous dissecting aneurysm of the cervical carotid artery, lohns Hopkins Med J 1970;126: I54-9. Submitted Feb. 2, 1991; accepted Apr. 18, 1991.
B O U N D VOLUMES AVAILABLE TO SUBSCRIBERS Bound volumes of the JOURN~ OF VASCULARSURGERY for 1991 are available to subscribers only. They may be purchased from the publisher at a cost of $59.00 for domestic, $79.13 for Canadian, and $75.00 for international subscribers for Vol. 13 (January to June) and Vol. 14 (luly to December). Price includes shipping charges. Each bound volume contains a subject and author index, and all advertising is removed. Copies are shipped within 60 days after publication of the last issue in the volume. The binding is durable buckram with the journal name, volume number, and year stamped in gold on the spine. Payment must accompany all orders. Contact Subscription Services, Mosby-Year Book, Inc., 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, USA. In the United States call toll free: (800)325-4177, ext. 435I. In Missouri call collect: (314)872-8370, ext, 4351. Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular JOURNALsubscription.
extracranial carotid artery dissections are reported. Four dissections resulted in internal carotid artery occlusion. These patients complained of ipsilateral headache followed by contralateral hemiplegia. The other three dissections involved the common carotid artery and resulted in dual (one true and one false) lumens. Two of these dissections were asymptomatic. All dissections were treated nonoperatively with anticoagulant therapy. Neurologic deficits improved or disappeared in all symptomatic patients. On follow-up studies, one of the four internal carotid occlusions completely resolved with normalization of the duplex examination. All three dual lumen dissections remained patent on serial studies. Diagnostic duplex characteristics, both conclusive and supportive, of carotid dissections are described. Duplex scanning is shown to be accurate in diagnosing and ideally suited for serially following spontaneous carotid dissections. (J VAse SuR~ 1991;14:391-7.)
Spontaneous carotid dissection is an uncommon but increasingly identified cause of cerebral ischemia. 13 Appropriate treatment requires early recognition with an accurate diagnosis. Carotid angiography has been the usual modality to obtain this diagnosis. Also, because of the frequently evolving nature of these lesions, serial arteriographic studies have been required to determine the outcome of the dissection. Several articles in the literature describe angiographic features of carotid dissections. 1'4"s Duplex imaging characteristics of spontaneous carotid dissections are described in this report. Duplex scanning is shown to be ideally suited for the initial evaluation and serial follow-up of carotid dissections. PATIENTS A N D M E T H O D S
From July 1987 through May 1990 six patients with seven spontaneous carotid artery dissections (bilateral in one patient) were admitted to the Vascular Surgery Division of the Eastern Virginia Graduate School of Medicine. The medical records of From the Divisionof VascularSurgery,EasternVirginia Graduate School of Medicine, Norfolk. Dr. Early is currently at the Universityof Tennessee,Memphis. Presented at the Fifteenth Annual Meeting of the Southern Association for Vascular Surgery, Palm Springs, Calif., Jan. 23-26, 1991. Reprint requests: Roger T. Gregory,MD, 250 W. Brambleton Ave., Suite 101, Norfolk, VA 23510.
24[6/30273
these patients were reviewed to determine presenting symptoms, carotid duplex and angiographic findings, treatment, complications, and outcome. Carotid arteriograms were available for review in five patients. The remaining patient was transferred from another hospital for follow-up, and only the angiographic report was available. All patients had initial bilateral duplex scans. Serial duplex studies were then obtained to determine the outcome of the dissection. Follow-up ranged from 2 to 38 months. Patients in the early years of the study were examined with gray-scale duplex scanning. When color-flow duplex scanning became available, this modality was applied as well. RESULTS Patient data including age, sex, symptoms, and treatment are shown on Table I. The group was made up of five men and one woman. Ages ranged from 35 to 89 years (mean, 55 years). Table II describes the duplex and angiographic findings. In five patients the duplex findings were confirmed by angiography. In one patient (no. 6), the duplex scan was interpreted as demonstrating a common carotid artery (CCA) dissection and an occlusion of the internal carotid artery (ICA). An arteriogram later the same day confirmed the CCA dissection but demonstrated a patent ICA. This most likely represents a false interpretation of the duplex scan; however, the possibility of resolution of the ICA occlusion during 391
392
Journal of VASCULAR SURGERY
Early et aI.
intramural thrombus
B
intimal flap
Fig. 1. A, Longitudinal duplex scan of an occluded internal carotid artery. The intima (white line) is seen overlying the intramural thrombus. B, Schematic drawing demonstrates the dissection.
Table I. Carotid dissection patient data Patient
Age~sex
Symptoms
1
35/F
2
40/M
3
46/M
4
44/M
Left eye amaurosis fugax and left occipital headache; 24 hours later, right hemiplegia and aphasia Right eye amaurosis fugax and right temporal headache followed by left arm weakness Left facial, ear pain and left headache; several days later developed aphasia and right hemiplegia Left hemiplegia
5
78/M
Left eye amaurosis fugax
6
89/M
Right hemiplegia and aphasia
ICAD, Internal carotid artery dissection; CCAD, common carotid artery dissection.
Diagnosis Left ICAD Right ICAD Left ICAD Right ICAD Left CCAD Right CCAD Left ICA stenosis Left CCAD
Volume 14 Number 3 September 1991
Duplex scanning of carotid dissections 393
Fig. 2. Longitudinal color-flow scan (black and white copy) shows a tapered occlusion of the distal internal carotid artery.
Fig. 3. Carotid angiogram demonstrates a tapered internal carotid artery occlusion.
Table II. Carotid duplex and angiogram results
Patient
Diagnosis
Duplex scan
Angiogram
1 2
Left ICAD Right ICAD
Left ICA occlusion Right ICA occlusion
3
Left ICAD
4
Right ICAD Left CCAD Right CCAD Left ICA stenosis
Left ICA occlusion, intimal flap overlying intramural thrombus Right ICA occlusion Left CCA DLD Right CCA DLD Left ICA stenosis
Left CCAD
Left CCA DLD and occluded left ICA
5 6
Left ICA occlusion Right IGA occlusion 2 cm distal to the carotid bifurcation Tapered IGA occlusion Angiogram report: occluded right ICA Right CCA DLD, 2 cm from origin to 2 cm proximal to the bifurcation; left ICA stenosis, greater than 90% Left CCA DLD and patent left ICA
ICAD, Internal carotid artery dissection; CCAD, common carotid artery dissection; DLD, dual lumen dissection.
the short time interval between studies could not be ruled out. Two patterns of carotid dissection were seen. Dissections resulting in total occlusion of the 1CA occurred in four patients. The other three were CCA dissections resulting in dual carotid lumens with one true and one false lumen. The clinical manifestation of the dissections varied depending on which disease pattern was seen. In the dissections resulting in 1CA occlusions, ipsilateral headache was the presenting
symptom with contralateral hemiparesis occurring several hours to several days later. In contrast, two of the three CCA dissections resulting in dual lumens were asymptomatic. One of these was discovered contralateral to an occluding ICA dissection, and the other was contralateral to a symptomatic ICA stenosis. It is interesting to note that the only symptomatic CCA dual lumen dissection was in the patient with the initial duplex interpretation of ICA occlusion with the arteriogram showing ICA patency.
Journal of VASCULAR SURGERY
394 Early et al.
Fig. 4. B-mode duplex image of the common carotid artery demonstrates the dissected intima (arrow) and distal reentry point.
Fig. 1 is a gray-scale image demonstrating a dissection resulting in an occluded ICA. Blood dissecting behind the proximal tear causes a tapered occlusion. The intimal flap is seen overlying the intramural thrombus. Fig. 2 is a black and white copy of a color-flow duplex scan of the same patient revealing proximal patency with a distal occlusion. Fig. 3 is the arteriogram of this patient once again demonstrating the characteristic tapering occlusion of the ICA distal to the carotid sinus. Fig. 4 is an example of a dissection resulting in dual lumens. This gray-scale image shows the CCA with an intimal flap and the distal reentry point of the dissection proximal to the carotid bifurcation. Fig. 5, _A is a color-flow image of this patient demonstrating flow through both lumens. Different flow velocity in each lumen is depicted by different color intensity. Fig. 5, B is a cross-sectional view again showing the intimal flap with flow in the true and false lumen. Fig. 6 is the angiogram of this patient confirming the CCA dissection. Spectral analysis of the Doppler signal in these patients with dual lumens also demonstrated different flow velocities in each lumen. Serial follow-up duplex examinations were obtained on all patients. In all three patients with
dissections resulting in dual lumens, both lumens remained patent. Three of the four ICA occlusions remained occluded on follow-up scans. One patient (no. 1) had resolution of her occlusion with complete restoration of flow in the ICA with no evidence of an abnormality on follow-up duplex scanning. All carotid dissections were treated nonoperatively. Five patients were treated with initial heparin sodium therapy followed by conversion to oral warfarin for long-term anticoagulation. In the remaining patient a symptomatic ICA stenosis, contralateral to a spontaneous dissection, was treated with carotid endarterectomy followed by postoperative warfarin therapy. No complications as a result of anticoagulation developed in any patients. Both patients with asymptomatic CCA dissections remained asymptomatic during the follow-up period. All patients with symptoms from their carotid dissection had either complete resolution of symptoms or improvement with minimal residual neurologic deficit. DISCUSSION
The first case of spontaneous carotid artery dissection was reported by Jentzer in 1954. 6 A review of the literature in 1972 produced only 11 cases; five of these patients died of massive cerebral infarcts. 7 Carotid dissections were thought to be rare occurrences with poor outcome. With the increased use of carotid angiography to evaluate patients with cerebral ischemia, carotid dissections were reported more frequently. 1'2 Bogousslavsky et al.3 discovered carotid artery dissection in 2.5% of 1200 patients with a first stroke. Along with more frequent recognition of dissections, the typically less severe neurologic deficits resulting from carotid dissections were also realized, with several authors reporting complete resolution of dissections on serial arteriograms.3'8"10 Treatment in early reports included a variety of surgical procedures including external carotid artery to internal carotid artery bypass grafting, carotid ligation, carotid resection with vein graft interposition, thrombectomy, carotid endarterectomy, and superficial temporal to middle cerebral artery bypass grafting5 '9'~-13 These procedures produced varying success. With the recognition of less severe deficits and frequent complete resolution of symptoms, later series recommend nonoperative treatment with antiplatclet drugs or anticoagulation with serial arteriograms to monitor the response to therapy? -3'1+
Volume 14 Number 3 September 1991
Duplex scanning of carotid dissectiom 395
Fig. 5. Color-flow duplex scan of a common carotid artery dissection. L~t, Longitudinal view demonstrates different flow velocity in each lumen. Right, Transverse view demonstrates the common carotid artery (blue) dissection. Anticoagulation is proposed to reduce cerebral emboli and to prevent intraluminal and intramural clotting. Although angiography has been the standard for diagnosing and following carotid dissections, several other modalities have been described including ocular pneumoplethysmography, ''~ CT scanning, 16 magnetic resonance imaging, 17"I8 and duplex scanning. 3,~8,~9 Duplex scanning has several advantages over angiography. Duplex scanning can image the arterial lumen as well as the arterial wall to detect intramural thrombus. Both longitudinal and cross-sectional
views can be imaged. Duplex scanning can provide hemodynamic information regarding the severity of stenosis resulting from a dissection. Duplex scanning is noninvasive, less expensive than angiography, and can be performed on an inpatient or outpatient basis. Duplex scanning also has limitations. Since most dissections occur distal to the carotid bifurcation, imaging a high dissection may be impossible. Also, duplex scanning gives no information regarding intracerebral dissections or emboli. Therefore, angiography is required initially to detect intracerebral abnormalities. The pattern of carotid dissection in this series
396
lou~naaof VASCULAR SURGERY
Early et al.
serially observing patients with spontaneous carotid dissection. Table I I I lists duplex characteristics o f dissections. O u r current practice is to screen patients with suspected carotid dissection using duplex scanning. Those patients with evidence o f a dissection or other carotid abnormality u n d e r g o carotid a n g i o g r a p h y to confirm the diagnosis and determine the distal extent o f the dissection. T r e a t m e n t o f carotid dissection is controversial; no controlled study is available to determine the optimal therapy. O u r current practice is to initially anticoagulate these patients with intravenous heparin s o d i u m and follow this with longterm oral warfarin. Duplex scanning is then used to serially follow the response to anticoagulant therapy. REFERENCES
Fig. 6. Digital subtraction angiogram demonstrates a right common carotid artery dual lumen dissection.
T a b l e I I I . Duplex diagnostic characteristics o f carotid dissections Conclusive Two ICA or CCA lumens imaged, separated by an intimal flap Two separate ICA or CCA frequency curves on spectral analysis Stenotic carotid lumen with intima overlying intramural thrombus Tapered ICA occlusion with an intima! flap overlying occluding thrombus Supportive Long smoothly tapered ICA stenosis Occluded ICA in the presence of a typical clinical history ICA, Internal carotid artery; CCA, common carotid artery.
differs f r o m other reports. Dissections limited t o the C C A were seen in three patients. I n a recent review o f the literature, G r a h a m et al.2o f o t m d 264 cases o f spontaneous extracranial carotid artery dissections and reported only one case o f dissection limited to the CCA. A further review discovered only three other cases o f C C A dissection in the literature. 21'2~ T h e three cases in this report suggest that C C A dissection is n o t as rare as previously thought. This series o f patients demonstrates that duplex scanning is an accurate m e t h o d o f diagnosing and
1. Mokri B, Sun& TM Jr, Houser OW, Piepgras DG. Spontaneous dissection of the cervical internal carotid artery. Ann Neurol 1986;19:126-38. 2. Biller J, Hingtgen WL, Adams FIP Jr, Smoker WRK, Godersky JC, Toffol GL Cervieocephalic arterial dissections. A ten-year experience. Arch Neurol 1986;43:1234-8. 3. BogousslavskyJ, Despland PA, Regli F. Spontaneous carotid dissection with acute stroke. Arch Neurol 1987;44:137-40. 4. Fisher CM, Ojemann RG, Roberson GH. Spontaneous dissection of cervicocerebral arteries. Can J Neurol Sci 1978;5:9-19. 5. Houser OW, Mokri B, Sundt TM Jr, Baker HL Jr, Recse DF. Spontaneous cervical cephalic arterial dissection and its residuum: angiographic spectrum. AINR 1984;5:27-34. 6. Jentzer A. Dissecting aneurysm of the left internal carotid artery. Angiology 1954;5:232-4. 7. Ojemann RG, Fisher CM, Rich JC. Spontaneous dissecting aneurysm of the internal carotid artery. Stroke 1972;3:43440. 8. McNeill DH Jr, Dreisbach J, Marsden RJ. Spontaneous dissection of the internal carotid artery. Its conservative management with heparin sodium. Arch Neurol 1980;37: 54-5. 9. Pozzati E, Gaist G, Poppi M. Resolution of occlusion in spontaneously dissected carotid arteries. J Neurosurg 1982; 56:857-60. 10. Geeraert AJ, AI Saigh All. Spontaneous dissection of the carotid artery: an unusual cause of stroke in younger patients. Can Med Assoc J 1987;136:51-3. 11. Ehrenfeld WK, Wylie ES. Spontaneous dissection of the internal carotid artery. Arch Surg 1976;111:1294-301. 12. Roome NS, Aberfeld DC. Spontaneous dissecting aneurysm of the internal carotid artery. Arch Neurol 1977;34:251-2. 13. Miyamoto S, Kikuchi H, Karasawa J, Kuriyama Y. Surgical treatment for spontaneous carotid dissection with impending stroke. J Neurosurg 1984;61:382-6. 14. Hart RG, Easton JD. Dissections of cervical and cerebral arteries. Neurol Clin 1983;1:155-82. 15. Gee W, Kanpp HA, McDonald KM, Lin FZ, Curry JL. Spontaneous dissection of internal carotid arteries: spontaneous resolution documented by serial ocular pneumoplethysmography and angiography. Arch Surg 1980;115:944-9. 16. Petro GR, Witwer GA, Cacayorin ED, et al. Spontaneous
Volume 14 Number 3 September 1991
Duplex scanning of carotid dissections 397
dissection of the cervicalinternal carotid artery: correlation of arteriography, CT, and pathology. MR 1987;148:393-8. 17. Goldberg HI, Grossman R_I, Gomori JM, Asbury AK, Bilaniuk LT, Zimmerman RA. Cervical internal carotid artery dissecting hemorrhage: diagnosis using MR. Radiology 1986;158:157-61. 18. Rothrock IF, Lira V, Press G, Gosink B. Serial magnetic resonance and carotid duplex examinations in the management of carotid dissection. Neurology 1989;39:686-92. 19. Zirkie PK, Wheeler JR, Gregory RT, Snyder SO Jr, Gayle RG, Sorrell K. Carotid involvement in aortic dissection diagnosed by duplex scanning. J VAsc SURG 1984;1:700-3.
20. Graham JM, Miller T, Stinnert DM. Spontaneous dissection of the common carotid artcry. J VAsc SURG 1988;7: 811-3. 21. O'Dwyer JA, Moscow N, Trevor R, Ehrenfeld WK, Newton TH. Spontaneous dissection of the carotid artery. Radiology 1980;137:379-85. 22. Burklund CW. Spontaneous dissecting aneurysm of the cervical carotid artery, lohns Hopkins Med J 1970;126: I54-9. Submitted Feb. 2, 1991; accepted Apr. 18, 1991.
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