From the Department of Neurology (J.W., S.A., F.D.), and the Division of
Cardiology, Department of Medicine (R.H., M.G.), The Mount Sinai School of
Medicine, New York, NY.
Correspondence to Jesse Weinberger, MD, Department of Neurology, Box 1052, The Mount Sinai School of Medicine, 1 Gustav Levy Place, New York, NY 10029. E-mail JesseWeinberger{at}mstplink.mssm.edu
Methods—In the current study, transcutaneous B-mode
ultrasonography was performed to image the aortic arch through a
lateral supraclavicular window, and the results were compared with
those of TEE in 20 patients. The aorta was subdivided into the proximal
ascending (PAsc), distal ascending (DAsc), proximal aortic arch (PAA),
and distal aortic arch (DAA) to be certain the plaques identified by
each technique were the same. Plaques were characterized as simple
(<4 mm thick) or complex (>4 mm thick).
Results—In the PAsc, 8 simple plaques were identified with TEE
but not with B-mode. In the DAsc, 1 complex plaque was identified with
both techniques, and B-mode identified 1 additional complex and 1
simple plaque. In the PAA, 6 simple and 5 complex plaques were
identified by both techniques, and TEE identified 1 additional complex
plaque. In the DAA, TEE identified 2 simple and 2 complex plaques;
B-mode identified 3 complex plaques.
Conclusions—B-mode imaging compared favorably with TEE in
identification of plaques in the aortic arch and distal ascending
aorta, although it could not identify simple plaques in the proximal
ascending. B-mode could visualize plaques not seen by TEE in the distal
ascending aorta. B-mode ultrasonography is complementary to TEE in
performance of a comprehensive assessment of plaque in the
aortic arch and provides a noninvasive method for sequential studies of
plaques that can be visualized.
In the current study, noninvasive percutaneous
real-time B-mode ultrasonography was used to visualize the aortic arch
and identify atherosclerotic plaque. B-mode ultrasonography is an
established technique for defining atheroma in the carotid
artery bifurcation and has provided the basis for many studies of the
relationship between plaque morphology and atheroembolic stroke from
the carotid.12 13 14 15 16 17 18 19 Correlation with TEE was made
in 20 consecutive stroke patients to determine whether B-mode was able
to visualize aortic plaque and to compare the morphological
characteristics revealed by B-mode with those shown by TEE.
The B-mode studies were performed by one of the investigators (J.W.),
who was aware of the clinical findings of the patient. The TEE studies
were performed without knowledge of the clinical findings in the
patient.
B-Mode Ultrasonography
For purposes of comparing TEE and B-mode ultrasonography, the arch was
subdivided into segments: the proximal ascending aorta, distal
ascending aorta, proximal aortic arch, and distal aortic arch. This
ensured that the same plaque was being imaged by each technique. The
origin of the innominate artery was taken as the border between the
proximal and distal arch, as seen in the schematic diagram of the arch
(Fig 2
TEE was performed with the patient in the lateral decubitus position. A
multiplane probe (ATL HDI 300 or Hewlett Packard HP-2500), with
frequencies ranging from 5 to 7 Mhz, was used. Topical
anesthesia was accomplished with Cetacaine (Cetylite
Industries) and lidocaine, and intravenous sedation when
needed was titrated with Demerol (Sanofi Winthrop) and Versed (Roche
Laboratories). Twenty sections of the arch were visualized and aortic
plaque was identified. The aorta was subdivided into the same segments
as the B-mode scans for comparison. Calculations of sensitivity and
specificity comparing B-mode and TEE were not made, because it is known
that TEE does not visualize all aortic plaques that can be seen with
open aortography, particularly in the distal ascending
aorta.11
Plaques were characterized as simple if they were <4 mm thick and
complex if they were >4 mm thick.7 9 They
were also described as sessile, crescentic, pedunculated, or flat.
All complex plaques visualized with TEE were also identified with
B-mode sonography. The morphological conformation of the plaques were
also similar, indicating that the same plaques were being seen. Both
techniques showed the plaques as pedunculated (Fig 3
Toyoda et al5 reported a 42% prevalence of
aortic atheroma identified by TEE in 62 patients with
clinical criteria of embolic stroke. Amarenco et
al4 found complex aortic plaques in 50% of 12
patients with embolic stroke for which no other etiology had been
determined. Horowitz et al6 reported mobile
aortic plaques in 4% of 183 patients with cerebral infarction.
Amarenco et al7 demonstrated that the prevalence
of complex aortic plaques >4 mm thick on TEE was significantly
higher in stroke patients compared with control patients, a finding
confirmed by Jones et al.8 The French Study of
Aortic Plaques in Stroke Study Group9 documented
an incidence of recurrent brain infarction of 11.9 per 100 person-years
in stroke patients with aortic wall thickness of >4 mm and 3.5
per 100 person-years in stroke patients with aortic wall thickness of
<4 mm, indicating that complex atherosclerotic plaque in the
aortic arch is a significant predictor of recurrent brain infarction.
The increased frequency of recurrent brain infarction in patients with
complex aortic plaques was confirmed by Mitusch et
al.10 In these studies the population was small,
and treatment modalities and concomitant risk factors were not
accounted for.20 21 22 Repeat TEE to document
changes in aortic plaque morphology consistent with an embolic
event was not performed, so it is uncertain whether embolization of
aortic plaque was the etiology or whether aortic arch
atherosclerosis was a marker for more severe
cerebrovascular disease.20 21 22
Correlation of the plaque morphology of ultrasound images of aortic
plaque on TEE and pathological specimens has been limited because most
aortic plaques are not removed surgically. Tunick et
al2 reported morphological correlation of one
complex symptomatic plaque removed surgically with the
presence of thrombus. Amarenco et al3 identified
ulceration on pathological specimens of aortic plaque described at
autopsy but did not correlate these findings with ultrasound
images.
The correlation of ultrasonographic carotid plaque morphology and
histology has been described in several studies.
Heterogeneous lucencies have been associated with
intraplaque and intraluminal thrombus and acute hemorrhage into
plaque.12 13 18 These findings are significantly
more frequent in symptomatic
plaques12 13 and have predictive value for future
symptoms.14 15 19 Plaque configuration also
appears to play a role, with crescentic plaques with scalloped borders
having a greater frequency of ipsilateral ischemic
events.17 19 Recurrent symptoms are associated
with plaque growth in a crescentic
configuration.19 Imaging aortic plaque with the
same linear real-time B-mode ultrasonographic technique used to image
carotid plaque may allow for extrapolation of plaque characteristics
from the carotid to the aortic arch.
Noninvasive B-mode imaging can visualize atherosclerotic plaque in the
distal ascending aorta and aortic arch. Plaques in the proximal
ascending aorta that are seen with TEE cannot be visualized, but almost
all of these are simple plaques. Complex plaques visualized with
epiaortography during cardiac surgery are located primarily in the
curvature of the arch from the distal ascending aorta to the proximal
descending aorta,11 which can all be seen with
B-mode ultrasonography in most patients. B-mode may be more sensitive
than TEE in identifying plaques at the junction of the ascending aorta
and the arch, which can be obscured by the
bronchi.11
Real-time B-mode ultrasonography of the aortic arch is a noninvasive
method that can be incorporated into the neurovascular evaluation of
patients with stroke and transient ischemic attack at the time
duplex examination of the carotid bifurcation is performed. Patients
who would not normally undergo TEE can be screened for aortic plaque,
and if plaque is identified a TEE can be performed to corroborate the
findings. In patients for whom visualization of the aortic arch is not
definitive with B-mode, TEE can be performed if there is a clinical
indication that the stroke was embolic. TEE is often performed in
patients suspected of having a cardioembolic stroke. In these patients,
B-mode can supplement the TEE to visualize the portions of the arch
that may be difficult to visualize with TEE. A combination of
transthoracic echocardiography and
B-mode ultrasonography of the aortic arch may be sufficient in some
patients to rule out an embolic source. B-mode imaging of the aortic
arch should also be useful for sequential studies of plaques identified
with TEE that can be visualized with B-mode without subjecting the
patient to the discomfort of repetitive TEE examinations. This may be
of value in therapeutic trials of agents to prevent stroke from aortic
arch plaque, so that morphologic changes in plaque can be correlated
with method of treatment and cerebrovascular events.
The current study was performed to establish the technique of
percutaneous B-mode imaging of the aortic arch and
determine whether the plaques identified were similar to those seen
with TEE. The number of patients was small, and correlation with
methods of treatment and risk factors was not obtained. Further studies
will be required to establish the interobserver and intraobserver
reliability of the technique, and the sensitivity and specificity must
be documented in large numbers of patients before the technique can
achieve general applicability.
The technique has the potential for become a standard method of
visualizing atherosclerotic plaque in the arch of the aorta.
Received October 2, 1997;
revision received January 5, 1998;
accepted January 5, 1998.
2.
Tunick PA, Culliford AT, Lamparello PJ, Kronzon I.
Atheromatosis of the aortic arch as an occult source of
multiple systemic emboli. Ann Int Med. 1991;114:391–392.
3.
Amarenco P, Duyckaerts C, Tzourio C, Henin D, Bousser
M-G, Hauw J-J. The prevalence of ulcerated plaques in the aortic arch
in patients with stroke. N Engl J Med. 1992;326:221–225.[Abstract]
4.
Amarenco P, Cohen A, Baudrimont M, Bousser M-G.
Transesophageal echocardiographic
detection of aortic arch disease in patients with cerebral infarction.
Stroke. 1992;23:1005–1009.
5.
Toyoda K, Yasaka M, Nagata S, Yamaguchi T. Aortogenic
embolic stroke: a transesophageal
echocardiographic approach. Stroke. 1992;23:1056–1061.
6.
Horowitz DR, Tuhrim S, Budd J, Goldman ME. Aortic
plaque in patients with brain ischemia: diagnosis by
transesophageal echocardiography.
Neurology. 1992;42:1602–1604.
7.
Amarenco P, Cohen A, Tzourio C, Bertrand B, Hommel M,
Besson G, Chauvel C, Touboul P-J, Bousser M-G. Atherosclerotic disease
of the aortic arch and the risk of ischemic stroke.
N Engl J Med. 1994;331:1474–1479.
8.
Jones EF, Kalman JM, Calafiore P, Tonkin AM, Donnan
GA. Proximal aortic atheroma: an independent risk factor
for cerebral ischemia. Stroke. 1995;26:218–224.
9.
The French Study of Aortic Plaques in Stroke Group.
Atherosclerotic disease of the aortic arch as a risk factor for
recurrent ischemic stroke. N Engl J Med. 1996;334:1216–1221.
10.
Mitusch R, Doherty C, Wucherpfennig H., Memmesheimer C,
Tepe C, Stierle U, Kessler C, Sheikhzadeh A. Vascular events during
follow-up in patients with aortic arch atherosclerosis.
Stroke. 1997;28:36–39.
11.
Konstadt SN, Reich DL, Quintana C, Levy M. The
ascending aorta: how much does transesophageal
echocardiography see? Anesth Analg. 1994;78:240–244.[Medline]
[Order article via Infotrieve]
12.
Reilly LM, Lusby RJ, Hughes I Ferrel LD, Stoney RJ,
Ehrenfeld WK. Carotid plaque histology using real-time ultrasonography:
clinical and therapeutic implications. Am J Surg. 1983;146:188–193.[Medline]
[Order article via Infotrieve]
13.
Steffen CM, Gray-Weale AC, Byrne KE, Lusby RJ.
Carotid artery atheroma: ultrasound appearance in
symptomatic and asymptomatic vessels.
Aust N Z J Surg. 1989;59:529–534.[Medline]
[Order article via Infotrieve]
14.
Langsfeld M, Gray-Weale AC, Lusby RJ. The role of
plaque morphology and diameter reduction in the development of new
symptoms in asymptomatic carotid arteries. J Vasc
Surg. 1989;9:548–557.[Medline]
[Order article via Infotrieve]
15.
Johnson JM, Kennelly MM, Decesare D, Morgan S, Sparrow
A. Natural history of asymptomatic carotid plaque.
Arch Surg. 1985;120:1010–1012.
16.
Mercuri M, Bond MG. B-mode ultrasound characterization
of atherosclerosis. J Cardiovasc
Technol. 1992;10:277–291.
17.
Weinberger J, Robbins A. Neurologic symptoms associated
with nonobstructive plaque at carotid bifurcation: analysis by
real-time B-mode ultrasonography. Arch Neurol. 1983;40:489–492.
18.
Weinberger J, Marks SJ, Gaul JJ, Goldman B, Schanzer J,
Jacobson J, Dikman S. Atherosclerotic plaque at the carotid artery
bifurcations: correlation of ultrasonographic imaging with morphology.
J Ultrasound Med. 1987;6:363–366.[Abstract]
19.
Weinberger J, Ramos L, Ambrose JA, Fuster V.
Morphologic and dynamic changes of atherosclerotic plaque at the
carotid artery bifurcation: sequential imaging by real time B-mode
ultrasonography. J Am Coll Cardiol. 1988;12:1515–1521.[Abstract]
20.
Davila-Roman VG, Barzilai B, Wareing TH, Murphy SF,
Schectman KB, Kouchoukos NT. Atherosclerosis of the
ascending aorta: prevalence and role as an independent predictor of
cerebrovascular events in cardiac patients. Stroke. 1994;25:2010–2016.[Abstract]
21.
DiTullio MR, Sacco RL, Gersony D, Nayak H, Weslow RG,
Kargman DE, Homma S. Aortic atheromas and acute
ischemic stroke: a transesophageal
echocardiographic study in an ethnically mixed
population. Neurology. 1996;46:1560–1566.
22.
Di Tullio MR, Sacco RL, Homma S. Atherosclerotic
disease of the aortic arch as a risk factor for recurrent
ischemic stroke. N Engl J Med. 1996;335:1464. Letter.
© 1998 American Heart Association, Inc.
Original Contributions
A New Noninvasive Technique for Imaging Atherosclerotic Plaque in the Aortic Arch of Stroke Patients by Transcutaneous Real-Time B-Mode Ultrasonography
An Initial Report
Abstract
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
Background and Purpose—Aortic arch
atherosclerotic plaque is a probable source of atheroembolic stroke.
Transesophageal echocardiography
(TEE) has been used to image the aorta of patients with stroke to
identify atherosclerotic plaque. TEE is moderately invasive and does
not always visualize plaques present in the distal ascending aorta
and proximal aortic arch.
Key Words: aortic arch • atherosclerosis • echocardiography, transesophageal • ultrasonography
Introduction
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
Morphological studies
of postmortem specimens and clinical studies with
transesophageal echocardiography
(TEE) have established an association between atherosclerotic plaque in
the aortic arch and ischemic stroke for which no other
coexisting etiology could be identified.1 2 3 4 5 6 7 8 9 10 TEE
is now performed on a routine basis in stroke patients to identify
plaques in the aortic arch that could be a potential source of
atheroembolic stroke. TEE is moderately invasive and cannot be
tolerated by all patients. In addition, the distal ascending aorta as
it curves into the aortic arch often cannot be visualized well because
of obstruction by the bronchi.11
Subjects and Methods
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
Patients
B-mode ultrasonography of the aortic arch was performed on 20
consecutive stroke patients. TEE was performed on 20 of these patients
within 3 days of the B-mode study. The TEE was performed without
knowledge of the B-mode results, and the B-mode was performed without
knowledge of the TEE results. The results of both studies were compared
at the end of the collection of 20 sequential cases. The location of
the plaque and the morphology of the plaque were determined in each
study before comparison of the results.
B-mode ultrasonography of the aortic arch was performed with an
Acuson XP 128 color-flow duplex Doppler instrument, with use of an
L7 phased-array linear probe at 7.5 MHz. Doppler examination was
performed at 5.0 MHz. A lateral supraclavicular approach was used to
visualize the ascending aorta, aortic arch, and proximal descending
aorta. The angle of insonation required to visualize the arch produces
an image that is inverse to the true direction of the arch, with the
ascending aorta to the right and the arch curving to the left toward
the descending aorta. A schematic diagram of the technique for imaging
the aortic arch is shown in Fig 1
.
View larger version (25K):
[in a new window]
Figure 1. Schematic diagram of the technique of performing
real-time B-mode ultrasonography of the aortic arch. The patient is
examined in a sitting or lying position, but the sitting position
provides better visualization. The probe is placed in the
supraclavicular fossa, imaging from the right to the left. The position
of the aortic arch in the sonographic beam is shown as it traverses
from right to left and posteriorly over the heart. The B-mode image is
seen in reverse, with the ascending on the left and the descending on
the right, because it is taken in a lateral view as the arch courses
posteriorly over the heart. ).
View larger version (24K):
[in a new window]
Figure 2. Schematic diagram of the results of B-mode and TEE
examination of the aortic arch is shown. The location of plaques in the
aortic arch was divided into subdivisions: proximal ascending aorta,
distal ascending aorta, proximal aortic arch, and distal aortic arch.
The locations of complex and simple plaques seen with B-mode imaging
and TEE in the subdivisions of the aortic arch are identified. Complex
plaques are denoted as large, irregular shapes and simple plaques as
small, regular shapes.
Results
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
TEE identified 8 simple plaques on the wall of the proximal
segment of the ascending aorta. This segment could not be visualized
well with B-mode ultrasonography, although the wall of the proximal
ascending aorta could be seen in 12 of the 20 cases with B-mode. In the
distal ascending aorta, B-mode identified 2 complex and 1 simple
plaque, whereas TEE identified only 1 complex plaque (Fig 2
). In the
proximal aortic arch, TEE identified 6 simple and 4 complex plaques,
and B-mode identified 6 simple and 3 complex plaques. In the distal
aortic arch, TEE identified 2 simple and 2 complex plaques; B-mode
identified 3 complex plaques. The additional complex plaque seen in the
distal aortic arch on B-mode was the same as the additional plaque seen
as being in the proximal aortic arch on TEE, but it was localized to
different segments by the two techniques. The results are summarized in
the Table and in a schematic diagram (Fig 2).
View this table:
[in a new window]
Table 1. Localization of Simple and Complex Plaques in the Proximal
Ascending Aorta, Distal Ascending Aorta, Proximal Aortic Arch, and
Distal Aortic Arch Visualized With B-Mode Ultrasonography and TEE ) and proliferative (Fig 4). Mobility of plaque could be seen as
well with both techniques. TEE was able to detect simple plaques not
seen with B-mode imaging, particularly in the proximal ascending
aorta.
View larger version (50K):
[in a new window]
Figure 3. A pedunculated plaque in the proximal aortic arch
visualized with B-mode ultrasonography (A) and TEE (B). The shape of
the plaque is the same, though linear scanning with B-mode appears to
delineate layers of density and lucency not visualized by sector
scanning with TEE.
View larger version (57K):
[in a new window]
Figure 4. A large proliferative plaque is seen with B-mode
(A) and TEE (B) at the curvature of the distal arch into the descending
aorta. The plaque is of intermediate echodensity, but no underlying
lucencies are seen.
Discussion
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
An association has been established between aortic plaque
identified by TEE and atheroembolic cerebrovascular disease. Tunick et
al1 first described the identification of
protruding masses with mobile components with TEE in patients who had
systemic embolic events during cardiac catheterization.
These observations were further extended to patients with embolic
stroke, and it was confirmed through pathological examination that
these masses were atherosclerotic.2 Amarenco et
al3 performed pathological examinations of 500
consecutive patients with cerebrovascular and other neurological
diseases and found a prevalence of aortic plaque of 57.8% in patients
with no known cause of cerebral infarction and 22% in patients with
other possible etiologies of cerebral infarction.
References
Top
Abstract
Introduction
Subjects and Methods
Results
Discussion
References
1.
Tunick PA, Kronzon I. Protruding atherosclerotic
plaque in the aortic arch of patients with systemic embolization: a new
finding seen by transesophageal
echocardiography. Am Heart J. 1990;120:658–660.[Medline]
[Order article via Infotrieve]
This article has been cited by other articles:
 |
|
 |
|
  A. Hussein, D. Hilal, O. Hamoui, H. Hussein, L. Abouzahr, S. Kabbani, and E. Chammas Value of aortic arch analysis during routine transthoracic echocardiography in adults Eur J Echocardiogr, July 1, 2009; 10(5): 625 - 629. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A Harloff, P Dudler, A Frydrychowicz, C Strecker, A L Stroh, A Geibel, C Weiller, A Hetzel, J Hennig, and M Markl Reliability of aortic MRI at 3 Tesla in patients with acute cryptogenic stroke J. Neurol. Neurosurg. Psychiatry, May 1, 2008; 79(5): 540 - 546. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Kronzon and P. A. Tunick Aortic Atherosclerotic Disease and Stroke Circulation, July 4, 2006; 114(1): 63 - 75. [Full Text] [PDF]
|
|
|
|
 |
|
 J. A. Bittl and L. R. Caplan Stroke after percutaneous coronary interventions J. Am. Coll. Cardiol., April 7, 2004; 43(7): 1168 - 1169. [Full Text] [PDF]
|
|
|
|
|
|
E. Schwammenthal, Y. Schwammenthal, D. Tanne, A. Tenenbaum, A. Garniek, M. Motro, B. Rabinowitz, M. Eldar, and M. S. Feinberg Transcutaneous detection of aortic arch atheromas by suprasternal harmonic imaging J. Am. Coll. Cardiol., April 3, 2002; 39(7): 1127 - 1132. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. A. Fayad and V. Fuster Clinical Imaging of the High-Risk or Vulnerable Atherosclerotic Plaque Circ. Res., August 17, 2001; 89(4): 305 - 316. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. R. Caplan Lice, Fleas, and Strokes Arch Neurol, August 1, 2000; 57(8): 1113 - 1114. [Full Text] [PDF]
|
|
|
|
 |
|
 P. A. Tunick, G. A. Krinsky, V. S. Lee, and I. Kronzon Diagnostic Imaging of Thoracic Aortic Atherosclerosis Am. J. Roentgenol., April 1, 2000; 174(4): 1119 - 1125. [Full Text] [PDF]
|
|
|
|
 |
|
 L. R. Caplan Multiple Potential Risks for Stroke JAMA, March 15, 2000; 283(11): 1479 - 1480. [Full Text] [PDF]
|
|
|
|
|
|
P. A. Tunick and I. Kronzon Atheromas of the thoracic aorta: clinical and therapeutic update J. Am. Coll. Cardiol., March 1, 2000; 35(3): 545 - 554. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Geraci and J. Weinberger Natural history of aortic arch atherosclerotic plaque Neurology, February 8, 2000; 54(3): 749 - 749. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Weinberger, N. Papamitsakis, A. Newfield, J. Godbold, and M. Goldman Plaque Morphology Correlates With Cerebrovascular Symptoms in Patients With Complex Aortic Arch Plaque Arch Neurol, January 1, 2000; 57(1): 81 - 84. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||