Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3643_Библиотеки_им_академика_М_И_Перельмана.pdf
123
Fig. 5.18 Carotid dissection (A) and Carotid dissection (B). ECD with
spectral analysis and Duplex demonstrate stump fl ow at the level of the
carotid bulb ( upper panels ). Echography ( black and white ) demon-
strates the hypoechogenic thrombus in the ICA ( lower left panel ) and
with color-coded echo, the disappearance of fl ow distal to the bulb
( lower right panel )
5 Diagnostic Approach to Cerebrovascular Disease: Ultrasound
124
Fig. 5.19 Carotid artery dissection (2). Spontaneous bilateral dissection of the ICA: ECD examination demonstrating stump fl o w
Fig. 5.20 Transposition (inversion) of the carotid bifurcation. This variation can be readily demonstrated with ICA placed medially and the ECA
laterally. Note that in this patient, the ICA is thrombosed (absent fl ow – right panel )
A. Nistorescu and H. Muresian
125
Fig. 5.21 CAS. Echotomographic aspect of the stented ICA and of the carotid bifurcation, seen longitudinally ( upper panels ) and transversally
( left lower panel ). The fl ow in the ICA appears normalized ( right lower panel )
Fig. 5.22 Aneurysm of the ICA – endovascular repair (1). A black and white ( left panel ) and color ( right panel ) imaging of an internal carotid
artery stenting (after ICA traumatic dissection). Normal fl ow pattern
5 Diagnostic Approach to Cerebrovascular Disease: Ultrasound
126
Fig. 5.23 Intrastent stenosis. The same patient as in Fig. 5.22 at 1-year
checkup. There is an intrastent stenosis; the hypoechogenic thrombus is
well visible ( upper panels ). Restriction of fl ow and stenosis measure-
ment ( lower panels ): the degree of stenosis amounting at approximately
50–60 %
Fig. 5.24 CEA and patching. The aspect of the carotid bifurcation after CEA and insertion of a synthetic patch
A. Nistorescu and H. Muresian
127
Fig. 5.25 SBCE. Panel ( a ): echographic aspect of a severely stenosed
carotid bifurcation in a patient demonstrating the same type of lesion on
the opposite side also. The patient underwent SBCE. Panel ( b ): the
result of SBCE. Both carotid bifurcations are enlarged with synthetic
patches. Flow is normalized. Note the slight folding of the patch ( upper
left panel ) but with no consequences on fl o w
5 Diagnostic Approach to Cerebrovascular Disease: Ultrasound
128
Fig. 5.26 Control of bypasses in the superior aortic system (1). SCA-
to- ICA bypass by using a PTFE graft. This patient had occlusion of the
CCA on the left side. The carotid bifurcation and the ICA were patent
(patency was maintained through retrograde fl ow in the ECA from the
numerous collaterals in the neck). The graft was inserted between the
SCA and the carotid bifurcation (it is still patent after 7 years) and is
tunneled under the SCM
Fig. 5.27 Control of bypasses in the superior aortic system (2). The
superior limb of an ascending aorta-to-right carotid artery bypass (as
performed for aortic arch syndrome). In this case, the right CCA was
occluded. The bypass comprised a common trunk of the graft and two
or more branches, reaching the supraaortic trunks. In case of concomitant lesions at the level of the carotid bifurcation, CEA is concomitantly
performed (see Chap.
14 )
A. Nistorescu and H. Muresian
129
References
1. Johnston DC, Goldstein LB. Clinical carotid endarterectomy decision making: noninvasive vascular imaging versus angiography.
Neurology. 2001;56(8):1009.
2. Nederkoorn PJ, Mali WP, Eikelboom BC, Elgersma OE, Buskens
E, Hunink MG, Kappelle LJ, Buijs PC, Wüst AF, van der Lugt A,
van der Graaf Y. Preoperative diagnosis of carotid artery stenosis:
accuracy of noninvasive testing. Stroke. 2002;33(8):2003.
3. Sabeti S, Schillinger M, Mlekusch W, Willfort A, Haumer M,
Nachtmann T, Müllner M, Lang W, Ahmadi R, Minar
E. Quantifi cation of internal carotid artery stenosis with duplex US:
comparative analysis of different fl ow velocity criteria. Radiology.
2004;232(2):431.
4. Dawson DL, Zierler RE, Strandness Jr DE, Clowes AW, Kohler
TR. The role of duplex scanning and arteriography before carotid
endarterectomy: a prospective study. J Vasc Surg. 1993;18(4):673.
5. Ten Kate GL, van den Oord SC, Sijbrands EJ, van der Lugt A, de
Jong N, Bosch JG, van der Steen AF, Schinkel A. Current status and
future developments of contrast-enhanced ultrasound of carotid
atherosclerosis. J Vasc Surg. 2013;57(2):539–46.
6. Partovi S, Loebe M, Aschwanden M, Baldi T, Jäger KA, Feinstein SB,
Staub D. Contrast-enhanced ultrasound for assessing carotid atherosclerotic plaque lesions. AJR Am J Roentgenol. 2012;198(1):W13–9.
7. Wasserman BA, Wityk RJ, Trout 3rd HH, Virmani R. Low-grade
carotid stenosis: looking beyond the lumen with MRI. Stroke.
2005;36(11):2504–13.
8. Kobayashi M, Ogasawara K, Inoue T, Saito H, Suga Y, Ogawa
A. Endarterectomy for mild cervical carotid artery stenosis in
patients with ischemic stroke events refractory to medical treatment. Neurol Med Chir (Tokyo). 2008;48:211–5.
9. De Bray JM, Glatt B. Quantifi cation of atheromatous stenosis in the
extracranial internal carotid artery. Cerebrovasc Dis.
1995;5:416–26.
10. Gray-Weale AC, Graham JC, Burnett JR, Byrne K, Lusby
RJ. Carotid artery atheroma: comparison of preoperative B-mode
ultrasound appearance with carotid endarterectomy specimen
pathology. J Cardiovasc Surg (Torino). 1988;29(6):676–81.
11. Lammie GA, Wardlaw J, Allan P, Ruckley CV, Peek R, Signorini
DF. What pathological components indicate carotid atheroma activity and can these be identifi ed reliably using ultrasound? Eur
J Ultrasound. 2000;11(2):77–86.
12. Schulz UG, Rothwell PM. Association between arterial bifurcation
anatomy and angiographic plaque ulceration among 4,627 carotid
stenoses. Cerebrovasc Dis. 2003;15(4):244–51.
13. North American Symptomatic Carotid Endarterectomy Trial
Collaborators. Benefi cial effects of carotid endarterectomy in
symptomatic patients with length-grade carotid stenosis. N Engl
J Med. 1991;325:445–53.
14. European Carotid Surgery Trialist’Collaborative Group. MRC
European carotid surgery trial: interim results for symptomatic
patients with severe (70–99 %) stenosis or with mild (0–29%) stenosis. Lancet. 1991;337:1235–43.
Fig. 5.28 Spontaneous contrast in the IJV. Faint hypodensities resem-
bling a moving cloud are sometimes noticed in the lumen of the IJV. On
transversal sections these appear as concentric waves with a center-toperiphery development. At times, these hypodense shapes depict a fl ow
in opposite direction toward the head. The spontaneous contrast is
encountered postoperatively (possible after excessive traction of the
IJV), after placement of a central venous catheter and in hypercoagulable states. The phenomenon may also appear in patients with TIAs or
minor ischemic events. The low fl ow in the IJV was confi rmed at
MRA. No obstructive venous lesions are encountered in these cases,
and this may refl ect a predisposition for a hypercoagulable state
(although this was not certifi ed by coagulation tests). Should these
patients be put on oral anticoagulant medication still remains an open
question. In some cases, the same spontaneous contrast was noticed at
the level of CCAs with a heavier atherosclerotic load, after CEA of the
bifurcation. This raises again the question of performing or not more
extended endarterectomies over the CCA also (even in cases with CCAs
that show only diffuse atherosclerotic lesions with no critical stenosis)
5 Diagnostic Approach to Cerebrovascular Disease: Ultrasound
131
© Springer International Publishing Switzerland 2016
H. Muresian (ed.), Arterial Revascularization of the Head and Neck, DOI 10.1007/978-3-319-34193-4_6
Endovascular Approach: From Diagnosis to Therapy
Horia Muresian and Bodgan Dorobat
In cardiovascular medicine, angiography, while included
among the diagnostic procedures, is continuously reappraised and compared with other techniques and, not least,
criticized for its invasive potential regarding the need for
direct arterial access, administration of contrast agent, and
the radiation dose applied to the patient. Although initially
considered as “the golden standard” for imaging carotid and
vertebral artery lesions, a more recent inconsideration of the
method developed when compared to complementary techniques allegedly more innocuous or less invasive and which
may offer comparable diagnostic data.
From the pure diagnostic point of view, angiography however has particular advantages and conveys unparalleled
information. Furthermore, the therapeutic potential is mostly
overlooked. It is worthwhile underscoring the fact that angiography is generally performed in larger centers where the
possibility of applying endovascular procedures and the surgical backup does normally exist. Trained interventionalists
and surgical teams usually complete the background of the
angiography laboratory. This holds true especially in cardiovascular medicine and particularly for cerebrovascular disease, where the both endovascular and surgical treatments
should be readily available and, most often, complete each
other. As a consequence, this chapter will display and
endorse the particular role and advantage of a technique that
should be perceived in its entirety .
Angiography consents the evaluation of the entire cerebral arterial system: carotid and vertebral extra- and intracranial circulation and of the remainder superior aortic system.
Particulars on the direction of fl ow, velocity of fl ow, collateral
circulation, and parenchymal distribution complete the pure
arterial mapping. Venous circulation can be also optimally
visualized. Complex atherosclerotic lesions and characteristics of the plaque are adequately imaged particularly tandem
stenoses, ulcerated plaques, and thrombus formation on
plaque. An accurate evaluation of the intracerebral arterial
disease is of utmost importance as this will select a category
of patients who will benefi t from CEA: patients with moderate carotid stenosis and intracranial arterial disease [
1 ].
Eccentric plaques may not be precisely and rigorously evaluated especially if only standard projections are employed.
Plaque morphology evaluation does not represent a main
characteristic of angiography with the exception of ulcerated
and calcifi ed plaques. Whenever required, an angiographic
imaging of the coronary circulation, renal arteries, and inferior aortic system can be also performed. Generally speaking, a patient undergoing angiographic interrogation has a
complete and precise vascular assessment in a relative short
period of time and in a single session. Digital subtraction
angiography (DSA) has enabled reduction of the dosage of
contrast agent along with the use of smaller-caliber catheters
and has shortened the duration of the examination.
The main limits of angiographic diagnosis include its
invasive nature (arterial puncture, contrast agent, radiation),
costs, and periprocedural morbidity and mortality (hematoma at puncture site, arterial dissection, distal embolism in
the cerebral circulation, and stroke; death). The risk is proportional with age and comorbidities: diabetes, arterial
hypertension, renal failure, cerebrovascular disease, and
peripheral artery disease. Patients under dual antiplatelet
therapy or triple antithrombotic therapy are at particular risk
for the development of rapidly extensive hematoma from the
puncture site. Subclinical or silent cerebral embolism after
angiography may occur with a higher frequency than
expected [ 2 ] most probably from the manipulation of dis-
eased arteries or from inadvertently passed air, in spite of
rigorous preventive measures. The best imaging is obtained
by selective catheterization of each main vessel; in patients
with more severe and extensive lesions of the supra-aortic
6
H. Muresian (*)
Cardiovascular Surgery Department , The University
Hospital of Bucharest , Bucharest , Romania
e-mail:
cvsurg@hotmail.com
B. Dorobat
Interventional Radiology Laboratory , The University
Hospital of Bucharest , Bucharest , Romania
e-mail:
bdorobat@gmail.com
132
arteries, the hazard of cerebral embolism is consequently far
greater. Not least, the selective catheterization of the neck
vessels is best achieved from the femoral route; in patients
with aorto-iliac disease, the angiographic imaging resulting
from accessing the brachial route may result unsatisfactory.
In the context of no-nil risk, angiography will remain a
second-choice diagnostic tool in asymptomatic patients and
in patients in whom no surgical or endovascular therapy is
contemplated. In these patients, ultrasound examination is
followed by either angio-CT or MRA if there is suspected
disease at more proximal level (origin of CCA, aortic arch).
Even in severe multivessel disease (carotid and vertebral
artery disease, subclavian arteries, vertebral steal syndrome,
etc.), valid information can be obtained by using noninvasive methods (a detailed diagnostic workup also appears
questionable in asymptomatic patients, and some authors
prefer performing only a periodic follow-up by ultrasound). Angiography remains to be indicated in symptomatic patients and in patients who will theoretically undergo
endovascular or surgical repair or when non-atherosclerotic
disease is suspected (vasculitis, dissection). CT and MRI
also have the additional advantage of imaging the cerebral
parenchyma and are more indicated in patients with recent
stroke. Detection of silent or multiple small brain infarcts
may change the therapeutical strategy, and CT and MRI have
particular advantages over angiography in these cases.
Angiography appears to be superior to other diagnostic
tests in detecting near occlusion of the ICA – an important
detail for further therapeutic planning, as total occlusion of the
ICA contraindicates any revascularization maneuver. On the
other hand, the accuracy of noninvasive methods appears to be
reduced in diagnosing carotid stenoses between 50 and 69 %
(as compared with stenoses of higher degree); in this respect,
angiography may select a particular category of patients in
whom a complete mapping of the cerebral circulation may be
benefi cial for stroke prevention (patients with concomitant
intracranial stenotic lesions). Angiography allows the clear
distinction between near occlusion of the ICA and occlusion
of the same but with a patent ascending pharyngeal artery
simulating on ultrasound interrogation a near-occluded ICA
(the ascending pharyngeal artery having a deep cervical course
similar to that of the ICA toward the cranial base). Longstanding stenoses of the ICA at origin may complicate with
hypoplasia of the distal (intracranial) ICA and with the development of collateral circulation from the contralateral carotid
and/or from the vertebrobasilar system. In these cases, revascularization has little (if any) effect and the therapeutic indication can be adjudicated with angiography.
Angiography is not routinely used as a screening test or as
initial diagnostic tool. Patients are generally selected following the clinical examination and the ultrasound interrogation.
Bypassing angiography before surgery requires that noninvasive tests be highly specifi c as well as sensitive [ 3 ].
Combining ultrasound and MRA may obviate the need for
angiography but only when the two diagnostic methods do
agree [
4 , 5 ]. (The particular indications of each of the remain-
der diagnostic methods are presented in Chaps.
5 and 7 ).
As mentioned before, the evaluation of fl ow represents an
important feature of angiographic evaluation. The direction
of fl ow (e.g., the presence of inverted fl ow in one of the VAs),
the velocity, and, not least, the direction of fl ow in collateral
vessels are all details easily and quickly obtainable with
angiography (as compared with other diagnostic techniques).
The signifi cance of a carotid stenosis can be readily appreciated when the ACA and MCA are fi lling from the opposite
ICA. The same applies when arteries pertaining to the anterior circulation are fi lled from the posterior circulation
through the PCommA.
Angiography allows a speedier evaluation of technical
failures after CAS or CEA and the prompt treatment of these.
Distal stenosis, spasm of the ICA, distal embolization,
thrombus developing at the origin of the ICA, distortion of
the carotid bifurcation after CAS of CEA, intimal fl aps (plus/
minus more distal dissection), and so forth are all amendable
by the endovascular route after completion angiogram.
Longer, tandem, serial, or atypical arterial stenoses (e.g.,
spur-like; stenosis and adjacent ulceration) are diffi cult to
appreciate by echo, CT-angio, or MRA and especially regarding the hemodynamic impact of the lesions, considered both
singularly and in conjunction. An important question arises
however at this point: “what is the real hemodynamic impact
of serial carotid stenoses or do these become critical under
certain conditions?” Two comparisons are offered by the coronary circulation and by the arterial circulation in the lower
legs: with augmented demand (as under stress or effort),
sequential stenoses may have similar hemodynamic impact
as a singular high-degree lesion leading to angina or claudication. Should this apply in the cerebral circulation, it will
select a category of patients who could benefi t from CEA.
Lesions at the level of the CCA may build up additional
hemodynamic burden over those at the origin of the ICA, but
some other aspects merit a more detailed discussion. The
CCA may appear more diffusely diseased in some instances
with plaques that do not appear as “hemodynamically signifi cant” but which will limit clamping either due to calcifi cations or due to their unstable nature. Not least, the evolving
potential of such lesions is diffi cult to envisage. Occlusion of
the CCA may occur postoperatively at some time, leading
either to total occlusion of the CCA and ICA or only to a
limited occlusion of the CCA up to the level of the bifurcation (the ICA remaining still patent while fed through the
ECA). Angiographic evaluation can assist in determining
which patients could benefi t from a more extensive surgery.
In our experience, we carefully examine the CCAs both
angiographically and intraoperatively; a safe clamping is
obtained by a more extensive exposure of the CCA and by
H. Muresian and B. Dorobat
133
choosing a disease-free segment of the CCA. If multiple and
especially “unstable, vulnerable, soft, or ulcerated” plaques
are encountered, the CCA is treated also either by performing an enlarged CEA and patching or by segmental excision
of the CCA and replacement with a vascular graft (Fig.
6.1 ).
Alternatively, the carotid bifurcation is treated surgically and
the lesion(s) on the CCA is stented (Fig. 6.2 ).
Another advantage of angiography resides in the evalua-
tion of the disease in the ECA (Fig. 6.3 ). Carotid plaques fre-
quently extend into the ECA for variable distances. The
atheroma in the ECA is generally pulled out during
CEA. More severe or more extended lesions in the ECA cannot however be removed safely in this manner, and occlusion
of the ECA may supervene after CEA; thrombosis may
either propagate or embolize into the ICA. Advanced disease
involving the ECA can be identifi ed during the routine preoperative angiographic evaluation and, thereupon, effi ciently
treated by endarterectomy extended into the ECA, double
patching, etc.
Angiographic interrogation may also select patients with
occluded ICAs who will benefi t from either CAS or CEA of
the ECA . The assessment of the origin, divisions, and anastomoses of the ECA branches with the intracranial ICA will
best predict in which patients the mentioned procedure is
profi table. So far, no other diagnostic technique appears
superior to angiography in this respect. Computational fl uid
dynamics will undoubtedly deliver important and clinically
useful data in the future [ 6 – 8 ].
Particular lesions are also best evaluated and quantifi ed
with the aid of angiography: coexistence of aneurysm and
stenosis of the cervical ICA ± kinking. The 3-D reconstruction of the complex lesion brings unparalleled details of surgical relevance (Fig. 6.4 ).
Angiography allows also the best appraisal of fl ow in the
revascularized vertebral artery (VA reimplantation into the
CCA), including the intracerebral distribution and direction
of fl ow (Fig. 6.5 ).
Completion angiogram remains a rapid and most valuable
method of detecting and treating suspected problems and
complications presenting after the operation. The results of
the technique applied can be readily verifi ed and quantifi ed
with the aid of intraoperative ultrasound Doppler probes:
fl ow measurements, presence of inadvertent turbulences,
intimal fl aps, residual or recently formed thrombi, and such
protocols should ideally follow any carotid operation. When
Doppler examination is either not available or in cases with
suspected failures or imperfection of the surgical construction and/or distal embolization into the cerebral circulation,
the urgent angiographic examination is mandatory. Selective
catheterization of the carotid artery and multiple projections
are deployed. Extra- and intracranial circulations are visualized. Whenever the case, patients are selected for redo surgery or CAS. Cerebral vasodilators (e.g., nimodipine) are
administered if cerebral vasospasm is evidenced or in cases
with multiple distal embolisms (Fig. 6.6 ).
Angiography probably diagnoses best and speediest, certain anatomical variations of the arch vessels . In our surgical
experience, we operated on three patients with ARSA (aberrant right subclavian artery, with retroesophageal course), to
correct the anomaly associated with aneurysmatic dilatation,
voluminous Kommerell diverticulum, or esophageal compression (Fig. 6.7 ). The aortic origin of the left VA (the most
common variation of origin of the VA) must be accurately
diagnosed, differentiating this condition from the occlusion
of the VA. Atypical clinical symptoms may also appear in
relation with anatomical variations of the supra-aortic arteries and are best revealed through angiography [ 9 ].
Various patterns of vertebral steal syndrome are best evi-
denced with the aid of angiography including the atypical
situations with occluded V0 and V1 (and even V2) segments
of the VA but with important steal through collateral circulation (Fig. 6.8 ).
Some particular situations will be presented, in order to
underscore the signifi cant role of endovascular diagnosis and
therapy.
Mega-dolicho internal carotid artery (Fig. 6.9 ). The fi rst
case illustrated is that of a 22-year-old male patient with
aneurysma-like dilatations of the ICA with intervening arterial segments of almost normal caliber. It is interesting to
note the fact that the disease was unilateral and with normal
vertebrobasilar system also. The ICA distal to the lesions
was successfully obliterated. The second case (Fig. 6.10 )
comprised kinking, stenoses, and dilatations of the cervical
segment of the ICA, and the entire diseased portion was
stented (with three stents).
Thrombosis of the ICA origin developing on otherwise
normally appearing arterial wall and no history of trauma,
either unilateral or involving both ICA origins. No particular
risk factors were present, except smoking and hypercholesterolemia. The two cases serve as sound paradigms also, as
one patient was treated by endovascular thromboaspiration
(Fig. 6.11 ), while the other was referred to surgery
(Fig. 6.12 ) – see fi gure legend for details. The recanalization
can be obtained by either balloon angioplasty, mechanical
clot disruption and thrombolysis, endovascular microsnare
device, the whirling roto-rooter clot maceration (X-ciser),
EPAR (endovascular photoacoustic recanalization) laser
device, or self-expanding Nitinol capture baskets.
Excessive kinking of the CCA or ICA is not an absolute
contraindication for performing the CAS. Angio-CT and
MRA cannot offer the dynamic image of the carotid bifurcation and even less details about the feasibility of passing the
sheath beyond the loops of the CCA (Fig.
6.13 ).
Late restenosis after CEA is generally diagnosed by ultra-
sound, subsequently confi rmed, and treated by angiography
and CAS. However, early suspicion of restenosis or technical
6 Endovascular Approach: From Diagnosis to Therapy