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_3924_Библиотеки_им_академика_М_И_Перельмана
.pdf
https://t.me/med1917
275
21
Brachiocephalic interventions
INTRODUCTION
Brachiocephalic interventions are being per-
formed with increasing frequency. Endovascular
approaches have replaced open surgery for most
cases of common carotid and subclavian diseases.
e role of carotid bifurcation stents is not yet
determined, but they will have some role in treat-
ment. In this chapter, these areas are described.
ARCH ASSESSMENT
As more data has been gathered about carotid
bifurcation stent placement using a transfemoral
approach, it has become clear that a signicant por-
tion of the stroke risk associated with the procedure
is related to the aortic arch. Because of this, patients
with arch disease or signicant angulation may
be at increased risk for carotid artery stent (CAS)
placement. Assessment of the arch, therefore, is
an important part of patient assessment and pro-
cedural planning. Preoperative assessment is best
performed using CTA. is permits simultaneous
assessment of arch conguration, calcication, and
associated atherosclerotic or thrombotic lesions.
Patients with signicant atherosclerotic and/or cal-
cic disease of the arch should be excluded from a
transfemoral approach to repair of an innominate,
common carotid or carotid bifurcation lesion.
Arch tortuosity is best assessed using the method
described in Figure 21.1. An elongated or tortuous
arch is common in elderly patients, especially those
with a long history of hypertension.
INNOMINATE AND COMMON
CAROTID ARTERY
ere are signicant dierences between interven-
tions in the carotid bifurcation and those in the
common carotid and subclavian–axillary arter-
ies. Most symptomatic carotid bifurcation lesions
present as a result of cerebral embolization, and
the potential for embolization with manipula-
tion is probably higher than for lesions of the
arch. Carotid bifurcation stent placement is per-
formed with some type of cerebral protection,
almost always just a single self-expanding stent,
and is performed with a 0.014 platform. Lesions
of the innominate and common carotid arteries
that require treatment occur less frequently than
carotid bifurcation stenoses. Subclavian artery ste-
noses and occlusions are common but oen they
do not need to be treated. Innominate, common
carotid, and subclavian lesions, compared with
the carotid bifurcation, are less likely to present
with embolization and are more likely to present
with hypoperfusion syndromes. Inow lesions of
the innominate or common carotid arteries may
require treatment prior to carotid bifurcation
repair and lesions of the subclavian artery may
require treatment prior to dialysis access place-
ment or the occasional case of upper extremity
bypass. ese are usually treated without a cere-
bral protection device and may be managed with
either a 0.014 or 0.035 system and with either self-
expanding or balloon-expandable stents. e most
common disease to occur in the innominate, com-
mon carotid, and subclavian arteries that requires
angioplasty and stent placement is disease that
occurs at the origins of these arteries. ese lesions
tend to be heavily calcied. ey also tend to occur
at the origin of the artery where the location of the
sheath for delivery of the stent is less stable. Lesions
at the origin of the innominate, common carotid,
and subclavian arteries are treated with balloon-
expandable stents for accuracy of placement and
crush resistance appropriate for highly calcied
lesions.
https://t.me/med1917
276 Brachiocephalic interventions
A detailed discussion of selective catheteriza-
tion of these arteries can be found in Chapter 9.
Chapter 11 covers arch aortography and selective
branch vessel arteriography. Supplies required for
interventions of the innominate, common carotid,
and subclavian arteries are listed in Table 21.1.
Focal lesions of the common carotid artery are
usually approached antegrade through a femo-
ral access. In the situation of combined common
carotid and bifurcation lesions requiring treat-
ment, a hybrid procedure may be performed,
which includes retrograde access through an
open exposure to treat the common carotid artery
lesion combined with carotid endarterectomy.
Occasionally, retrograde access through a distal
common carotid artery exposure is appropriate for
treatment of a de novo common carotid artery ori-
gin lesion in a patient with severe arch disease or in
conjunction with stent–gra placement for arch or
thoracic aortic disease.
Arch aortography is performed through a femo-
ral approach using a pigtail catheter and a pressure
injector, as described in Chapter 11. e image
intensier is best placed in the le anterior oblique
(LAO) position (see Chapter 9, Figure 9.1). An
image of the arch, the origins of its branches, and
the carotid bifurcation is saved on the monitor and
the image intensier is not moved until the artery
origin is cannulated. It is best to include within
the image the mid-ascending aorta on the bottom
of the eld and the carotid bifurcation on the top
ofthe eld.
ASSESSMENT OF ARCH BRANCH
LESIONS
Because these lesions are typically at the origins
of the arteries and are associated with the arch of
the aorta, imaging of the arch must be performed
in order to fully understand the extent of lesions
in these locations. Arch aortography in the LAO
position is one way to evaluate the origins of the
innominate, le common carotid, and le subcla-
vian arteries. To visualize the innominate bifur-
cation, which includes the origins of the right
subclavian and right common carotid arteries, a
right anterior oblique (RAO) projection is usually
required. If there is associated disease in the arch
of the aorta or lesions in middle segments of the
arch branches, it may inuence catheter placement
in an eort to avoid the worst part of the disease
and avoid embolization as a result of encountering
Table 21.1 Supplies for interventions of the innominate, common carotid, and subclavian arteries
a
Length Diameter
Guidewire Starting guidewire Bentson 180 cm 0.035 inch
Selective guidewire Glidewire
®
180 cm 0.035 inch (angled tip)
Exchange guidewire Amplatz Super Stiff
®
260 cm 0.035 inch
Catheter Flush catheter Pigtail 90 cm 5-Fr
Selective cerebral
catheter
Vertebral (Vert) 100 or 125 cm 5-Fr
Headhunter H1 100 cm 5-Fr
Vitek 125 cm 5-Fr
Simmons 1, 2 100 cm 5-Fr
Sheath Cerebral guide sheath Shuttle or Destination 90 cm 6-Fr or 7-Fr
Balloon Balloon angioplasty
catheter
Balloon diameter 5, 6, 7, 8, 9, 10 mm
Balloon length 2, 4 cm
Catheter shaft 120 cm 3-Fr or 5-Fr
Stent
b
Balloon-expandable
stent (premounted)
Stent diameter 6, 7, 8, 10 mm
Stent length 15–35 mm
Shaft length 135 cm
Self-expanding stent
(nitinol)
Stent diameter 8, 10, 12, 14 mm
Stent length 20, 40 mm
Delivery catheter 120 cm
a
Excluding carotid bifurcation balloon angioplasty and stenting.
b
No stents are approved by the FDA for routine usage in this vascular bed.
https://t.me/med1917
Principal techniques 277
arch disease. e arch and its proximal branches
may also be assessed using MRA or CTA. ese
are useful for planning the access and approach,
but are somewhat limited in accurate assessment
of lesion severity since they tend to overemphasize
the degree of stenosis. In addition, CTA tends to
overemphasize the calcium and these lesions are
generally heavily calcied. Both methods are very
helpful at delineating the anatomy of the area.
Prepare for the case by assessing the length of
the disease to be treated and choosing the stent
that is most likely to be used during the procedure.
Placement of stents using a transfemoral approach
will require a 70-cm sheath in a short person and
a 90-cm sheath in a normal sized to tall person.
If there is signicant calcium in the aorta, it may
inuence the type of catheter. A simple curve cath-
eter choice for crossing these lesions includes a
vertebral catheter and, for a complex curve cath-
eter, a Vitek catheter is frequently useful since it
may be pushed into the arch from the descending
aorta rather than dragged backward from the right
side of the arch to the le side of the arch. ere is
a choice with arch branch lesions as to whether a
small caliber (0.014- or 0.018-inch) or a 0.035-inch
diameter system would be best. In addition, with
respect to the planning and treatment of subclavian
lesions, it is quite oen valuable to approach these
lesions for either part of or all of the treatment by
using a brachial access, and this is discussed later.
is, however, should be decided, to the best extent
possible, at the beginning of the procedure.
PRINCIPAL TECHNIQUES
Access is obtained in the femoral artery. Systemic
anticoagulation is administered. A 5-Fr or 6-Fr
sheath is placed in the femoral artery and a 100-
cm length 5-Fr pigtail catheter is advanced so that
the head of the catheter is in the ascending aorta.
Arch aortography is performed. is demonstrates
the location of the lesion as well as its length and
approximate diameter. Subsequently, a Glidewire
®
is passed through the pigtail catheter and the
catheter is removed. An angled catheter, usually
a simple curve catheter or a vertebral catheter, is
advanced over the Glidewire
®
. e Glidewire
®
is withdrawn into the sha of the catheter. e
catheter is then withdrawn slightly and pointed
toward the location of the lesion at the artery ori-
gin that is intended for crossing. e so-called “no
touch” technique is used if possible. e catheter is
pointed in the appropriate direction. Occasionally,
a pu of contrast may be used to assist visualiza-
tion. e guidewire is used to gently probe the
roof of the arch to feel for the lesion and to get
across the lesion. Aer the Glidewire
®
has crossed
the lesion, it is then advanced into the mid-distal
A B
Fig. 21.1 Arch assessment. (A) Normal aortic arch in segments. The branches generally originate from
the “top” or superior aspect of the arch. All the branch origins are a substantial distance superior to
the horizontal line drawn across the upper, inner aspect (the inner curve) of the arch. (B) An elongated
arch, which is common in the elderly and those with hypertension. A line drawn across the upper inner
aspect of the arch readily demonstrates that the origin of the innominate artery is inferior to the line.
If the arch branch is inferior to or near this line, catheterization will be more challenging, may require
more attempts, and the arch branch origin may be resistant to sheath placement.
https://t.me/med1917
278 Brachiocephalic interventions
common carotid artery. If possible, the simple
curve catheter is advanced over the Glidewire
®
and
the carotid artery is road mapped to identify the
location of the carotid bifurcation to avoid inad-
vertently crossing it if crossing the bifurcation is
not required. Subsequently, a 0.035-inch diameter
sti exchange wire is advanced through the cath-
eter. e tip of the exchange wire is placed in a
way that is consistent with the degree of tortuosity
through which the sheath must pass. e tip of the
wire is usually placed in the distal common carotid
artery. For a tortuous arch, it may require place-
ment in the distal external carotid artery. is way,
there is more sti wire distal to the arch to create
a better rail. e sheath is then advanced over this
system with the sti exchange wire. Be careful to
not inadvertently advance the tip of the dilator for
the sheath across the lesion if this is not planned.
At some point, the dilator is held steady and the
sheath advanced over the dilator to achieve the last
couple of centimeters.
If the planned procedure is to take place using
0.035-inch compatible balloon catheters and
stent delivery catheters, the same sti guidewire
is maintained in place and used for treatment.
If it is desirable to switch to a 0.014-inch-based
system, then this is the time to do so, aer the
sheath is in place. Lesions distal to the origin of
the arch branch may be treated by placing a sti
0.014-inch diameter guidewire wire into the
external carotid artery. Lesions at the very ori-
gin of the arch branches leave no place within
the branch artery to put the sheath tip to make a
stable system. A0.014-inch diameter guidewire is
not as sturdy as a 0.035-inch diameter guidewire.
Because of the location of the lesion at the origin
of the artery, the only way to obtain a stable sheath
position and get the sheath close enough is to put
the tip of the sheath up close to the lesion using
a fairly heavy exchange guidewire. e lesion
may be predilated and then stented or managed
with primary placement. is is a judgment call.
Primary stent placement requires one less step
and one less opportunity to challenge the stability
of the system. However, when using a 0.035-inch
system, the caliber of the premounted stent may
be too large to cross a tight lesion without predila-
tion. A premounted, balloon-expandable stent is
advanced over the guidewire and then advanced
across the lesion. Small pus of contrast may
be administered to help position it. Just before
placement of the stent, the sheath must be with-
drawn slightly so that the lower end of the stent is
able to clear the upper end of the sheath when the
stent is expanded. When the sheath is withdrawn,
it creates an inherently less stable situation, so care
must be taken to maintain the guidewire position
without any withdrawal of the wire and to line up
and deploy the stent without wasting time.
e advantage of the 0.035-inch system in this
case is that this is a sturdier platform. e disad-
vantages are that the wire manipulation is quite
limited and also that the stent delivery catheter
lls the sheath and a larger sheath is required to
maintain the ability to inject contrast around the
stent delivery catheter in order to perform adjust-
ments in position prior to deployment. Ventilatory
motion and arch movement with the cardiac cycle
make this ne tuning of position necessary. e
capability should be maintained so that contrast
can be administered in small pus through the
sheath to conrm the optimal placement of the
stent prior to deploying it.
A lesion in the mid-common carotid artery
may also be encountered that is not at the com-
mon carotid artery origin. Because this is a rela-
tively mobile artery, if the lesion does not involve
the origin of the common carotid artery and there
is a length of at least 1 cm of reasonably sized and
nondiseased artery at the origin of the common
carotid artery, an option in this case is to use a
self-expanding nitinol stent. Although the trail-
ing end of the stent is dicult to place with a high
degree of accuracy, if there is a centimeter of open
space in the artery distal to its origin, this is usu-
ally adequate.
With respect to the innominate artery, sizing
issues are oen a problem. Because the artery is
somewhat short and there is oen a calcied ori-
gin lesion, placement of a self-expanding stent
is not advisable and a balloon-expandable stent
should be used. e innominate artery is larger
in diameter than the other arch branches and the
balloon-expandable stent must have a diameter of
10 mm or more and is usually delivered through a
sheath with a larger crossing prole, which must be
placed across the lesion in order to place the stent.
Imaging during stent placement should be deter-
mined by whether the lesion is directly at the origin
of the blood vessel or located more distally close to
the bifurcation. is is because the origin of the
innominate artery is better visualized in the LAO
https://t.me/med1917
Transfemoral approach to the common carotid artery 279
position and the bifurcation of the artery is better
seen in the RAO position of the image intensier.
e other concern with the innominate artery is
that it is typically a very unstable place to have a
sheath, especially when the origin of the artery is
being treated. Because this is an unstable system,
consider using a sti guidewire that extends out
into the right subclavian artery and can be placed
all the way into the axillary artery if necessary to
obtain more purchase and stability. Another way
to obtain more stability is to place two separate
0.014-inch diameter guidewires, one into the com-
mon carotid artery and one into the subclavian
artery, and then place a 0.035-inch compatible
stent delivery catheter over the combination of the
two wires. e combination of two dierent 0.014-
inch diameter guidewires is less than the diameter
of a single 0.035-inch diameter guidewire.
Most of these lesions can be treated using a
transfemoral approach, but sometimes the adjunc-
tive addition of a transbrachial approach is quite
helpful. Aer stent placement a follow-up bal-
loon angioplasty is usually performed. Care must
be taken with placement of balloon-expandable
stents to expand them adequately so that they are
in a stable position, but not to overexpand them
and cause injury to the artery and surrounding
tissues. Acompletion arteriographic study is then
performed through the sheath and if this is satis-
factory, the guidewire and sheath are removed.
TRANSFEMORAL APPROACH TO
THE COMMON CAROTID ARTERY
In proceeding with a transfemoral approach to the
common carotid artery, a guidewire and access
sheath are inserted (Figure 21.2). Heparin is
administered intravenously (75–100 U/kg). e tip
of the guidewire is placed in the arch. A 6-Fr or
7-Fr, 90-cm long, straight sheath with a radiopaque
tip is passed and the tip advanced to within a few
centimeters of the origin of the artery. e opera-
tor must decide whether to lead with the guide-
wire or with the catheter. If the lesion is located
at the very origin of the common carotid artery,
either the catheter or the guidewire may be used
to lead. Neither of these is optimal to lead because
they will be protruding from the end of the sheath,
which is mobile within the arch, and this is a rela-
tively unstable position for the whole platform.
Ifthe lesion is distal to the origin of the vessel, lead
with the catheter to cannulate the artery and then
advance the guidewire. e appropriate selective
cerebral catheter, 100–120 cm in length, is placed
through the sheath. e head of the selective cere-
bral catheter extends beyond the end of the sheath.
e cerebral catheter directs the guidewire into the
origin of the common carotid artery.
The steerable guidewire is advanced care-
fully beyond the common carotid artery lesion
and into the external carotid artery. The cere-
bral catheter may be advanced over the guide-
wire and into the external carotid artery. The
steerable guidewire is exchanged for an Amplatz
Super Stiff
®
guidewire or other long exchange
guidewire. After the stiff guidewire is in place
in the external carotid artery, the cerebral cath-
eter is removed. The dilator is replaced within
the long sheath and the sheath is advanced
carefully up to the artery origin. Avoid dotter-
ing the lesion with the dilator. It is usually best
to advance the sheath directly over the dilator
for the last few centimeters. After the tip of the
sheath is in place, additional arteriography and
heparin flushing may be performed through the
side arm of the sheath. The long sheath should
be flushed regularly and care must be taken to
avoid thrombus formation or microbubbles.
Carotid arteriography is performed through the
sheath with a small eld of view. e usual diam-
eters are 6–8 mm for the common carotid artery
and 8–12 mm for the innominate artery. e most
favorable lesions are focal and a 2-cm long bal-
loon is usually adequate. Usually, primary stent
placement is performed. Orice lesions are best
treated with a balloon-expandable stent. Other
lesions may be treated with either self-expanding
or balloon-expandable stents, since these are rela-
tively straight conduit arteries.
Self-expanding stent diameter should be 8 mm
for a 5–7 mm common carotid artery or 10 mm for
a 7–9 mm artery. e stent delivery catheters must
be 120 cm. e length of the stent should be kept to
a minimum. e stent delivery catheter is passed
over the guidewire, through the sheath, and into
position across the lesion (Figure 21.3). e stent is
deployed and postplacement dilation is performed,
followed by completion arteriography.
In each case, the sheath is close to the lesion
and it is withdrawn to uncover and deploy the
stent. If landmarks require rechecking, contrast
may be injected through the sheath prior to stent
https://t.me/med1917
280 Brachiocephalic interventions
deployment. Aerward, completion arteriography
may likewise be performed through the sheath.
Orice lesions require a very high degree of
placement accuracy since the proximal end of the
stent should protrude into the arch enough to con-
tain any arch plaque that has spilled over into the
common carotid artery. Orice lesions may also
be challenging from a femoral approach because
when the sheath is pulled back to expose the stent,
the tip of the sheath loses its purchase on the ori-
gin of the common carotid artery. e sheath
must be withdrawn carefully and the tip should be
parked as close to the end of the balloon as pos-
sible without impinging on it. Aer deployment,
A B C
D
F
G H
E
Fig. 21.2 Balloon angioplasty of the common carotid artery. (A) Arch aortography is performed
with a flush catheter. (B) The guidewire is replaced after the location of the common carotid artery
origin and the lesion is identified. (C) A long sheath is placed in the proximal descending aorta.
(D)Aselective cerebral catheter is advanced through the sheath and used to cannulate the common
carotid artery. The catheter must be at least 20 cm longer than the sheath. (E) The guidewire is
directed into the external carotid artery. (F) The sheath is advanced into the proximal common
carotid artery and an arteriogram is obtained. (G) Balloon angioplasty is performed. If the lesion
is in proximity to the bifurcation, the guidewire should be placed in the internal carotid artery.
(H)Completion arteriography is performed through the sheath.
https://t.me/med1917
Carotid bifurcation stent placement 281
postdilation of both ends of the stent is performed
using the same balloon.
CAROTID BIFURCATION STENT
PLACEMENT
Patient preparation for carotid bifurcation stenting
includes clopidogrel (75 mg/day for 5 days prior to
the procedure) and daily aspirin (325 mg). eaor-
tic arch, carotid arteries, and cerebral arteries are
evaluated prior to the stent procedure using arte-
riography, MRA, or CTA. Carotid bifurcation
stenting may be performed using a transfemoral or
a transcervical exposure, with a small number of
patients being best served by an approach through
the brachial or radial arteries. e procedure is
performed under local anesthesia with minimal
or no sedation to facilitate continuous neurologic
monitoring. An arterial line is placed for continu-
ous pressure monitoring and electrocardiography
leads for cardiac monitoring. Temporary pacer
pads should be available and patients with aortic
stenosis should have the temporary pacer pads in
place. Antihypertensive medications may be with-
held on the morning of the procedure, especially
beta blockers. Bradycardia occurs frequently with
balloon angioplasty of de novo carotid bifurcation
stenosis due to carotid sinus nerve stimulation,
and this may be sustained aer the procedure.
Femoral access is achieved and heparin adminis-
tered (100 U/kg). An activated clotting time (ACT)
is obtained and maintained at >250 seconds. e
same size femoral sheath access sheath is placed as
that anticipated for the procedure, usually either
6-Fr or 7-Fr. A oppy tip guidewire is placed in the
aortic arch and the image intensier rotated into
the LAO position to reect the best angle achieved
for viewing, as identied on the preoperative study.
e cerebral catheter of choice is placed over the
guidewire. Chapter 9 oers a discussion of carotid
catheterization and Chapter 11 discusses carotid
arteriography. e image intensier is maintained
A
B
C
Fig. 21.3 Stent placement in the common carotid artery. (A) After guidewire and sheath placement,
an arteriogram is obtained. (B) A self-expanding or balloon-expandable stent is delivered to the site
of the lesion or the angioplasty. (C) The stent is deployed while maintaining access to the common
carotid artery with the sheath.
https://t.me/med1917
282 Brachiocephalic interventions
in its xed LAO position and the bony landmarks
may be used to guide vessel cannulation. e
cerebral catheter is placed in the common carotid
artery origin. A hydrophilic, steerable guidewire is
advanced through the catheter and into the mid- to
distal common carotid artery. e location of the
carotid bifurcation can oen be identied on plain
uoroscopy due to the presence of vessel calcica-
tion. e guidewire is not permitted to pass into the
bifurcation. e cerebral cat heter is advanced so that
its tip is well seeded in the common carotid artery.
A road map of the carotid bifurcation is performed
(Figure 21.4). e position of the image intensier
may require adjustment to obtain the best image
showing the bifurcation and the separation of the
internal and external carotid arteries. Occasionally,
a lateral view is required. Multiple views may be
needed to best open the carotid bifurcation.
A B C
D
E F
Fig. 21.4 Carotid bifurcation stent placement. (A)The left common carotid artery is catheterized
and a road map is created of the bifurcation. (B) The Glidewire
®
is advanced into the external carotid
artery and the catheter advanced. (C) The stiff exchange guidewire is placed in the external carotid
ar ter y. (D) The angiographic catheter is withdrawn from the external carotid artery. (E) The sheath
is advanced over the stiff guidewire. (F) The tip of the sheath is placed in the mid- to distal common
carotid artery. (Continued)
https://t.me/med1917
Carotid bifurcation stent placement 283
e next step is selective cannulation of the
external carotid artery. is is performed with a
260-cm angled Glidewire
®
advanced under road
mapping and the cerebral catheter is advanced
into the external carotid artery. When common
carotid catheterization is performed with a simple
curve catheter, advancement of the catheter into
the external carotid artery is facilitated. When a
complex curve catheter is used to cannulate the
common carotid artery, it is sometimes possible
to advance the catheter into the external carotid
artery. However, frequently, it must be exchanged
for a simple curve catheter. An attempt should be
made to reach as distally into the external carotid
artery as possible. is allows adequate guide-
wire length beyond the bifurcation for subse-
quent placement of the carotid access sheath. e
Glidewire
®
is withdrawn from the cerebral cath-
eter and a 260-cm sti exchange guidewire, such
as an Amplatz Super Sti
®
, is placed in the external
L
M N O
G H I J K
Fig. 21.4 (Continued) Carotid bifurcation stent placement. (G) The exchange guidewire is withdrawn
from the external carotid artery. (H) The leading wire for the distal embolic protection device is
placed across the lesion. (I) The filter delivery catheter is passed across the carotid stenosis. (J) The
filter is deployed. (K) Predilation of the lesion. (L) The stent delivery catheter is advanced. (M) The
stent is deployed across the bifurcation. (N)Poststent dilation is performed, keeping the balloon
within the stent and only dilating the area of residual lesion within the stent. (O) After completion
angiography, the filter is removed.
https://t.me/med1917
Соседние файлы в папке Библиотека им академика М.И. Перельмана