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284 Brachiocephalic interventions
carotid artery. Before placing the exchange guide-
wire, check to make sure that there is backbleed-
ing from the catheter. If the catheter has been
advanced into a very small branch or if spasm has
occurred and there is no backbleeding, the inner
catheter surface may become lined with air bub-
bles. When the exchange guidewire is introduced,
these microbubbles may be pushed into the cere-
bral circulation and become emboli. Occasionally,
the catheter must be very slightly withdrawn to
restore backbleeding. When the sti exchange
guidewire is advanced, it is usually best to posi-
tion the image intensier in the LAO position. e
eld of view should include the top of the arch on
the inferior aspect of the monitor so that the last
turn from the arch into the common carotid artery
can be visualized as the sti guidewire rounds the
turn. Superiorly on the monitor, the tip of the cath-
eter is visualized and its position established using
bony landmarks. If there is signicant arch tortu-
osity, the last turn from the arch into the common
carotid artery may be a challenging angle. As the
sti guidewire enters the common carotid artery, it
may start to pull the catheter down from the exter-
nal carotid artery. If the tip of the catheter starts to
migrate inferiorly, this serves as an early warning
system that the catheter–guidewire apparatus has
too much tension in it and that an alternative plan
is required.
Aer the sti exchange guidewire is placed,
thesimple curve catheter is withdrawn leaving the
sti guidewire in the external carotid artery. e
access sheath in the groin is removed. A 6-Fr or
7-Fr 90-cm sheath is advanced over the sti guide-
wire into the common carotid artery. ere are
many sheath choices for this maneuver. Two good
choices are the Flexor
®
Shuttle
®
Guiding sheath
and the Destination
®
Peripheral Guiding sheath.
As the sheath is advanced, image the distal end of
the sti wire in the external carotid artery, includ-
ing the last turn exiting the arch and the tip of the
guidewire. If the tip of the guidewire starts to back
up, it indicates that the sheath is not advancing
appropriately over the wire.
e dilator tip for the carotid sheath is several
centimeters longer than the sheath itself and could
be inadvertently advanced into the bifurcation. e
outline of the dilator tip can usually be identied
under uoroscopy even though it does not have
a radiopaque marker. When the dilator reaches
its desired location in the mid- or distal common
carotid artery, it is held steady and the sheath may
be advanced over the dilator itself. Aer the sheath
is in place, the dilator is withdrawn and carotid
angiography performed through the sheath to be
sure that the tip of the sheath is optimally placed.
e tip of the sheath should be a minimum of
5–10cm inside the common carotid artery so that
the position of the sheath is stable. Aer the lter
is deployed, if the sheath begins to back up, options
for managing this are limited. e sti guidewire
is removed, and the image intensier optimally
positioned to road map the bifurcation.
Some type of embolic protection is standard
in CAS placement. Embolic protection may be
performed using one of a variety of distal protec-
tion devices. Several distal lters are available and
some examples are discussed in Chapter 20. ere
are also occlusive devices, which use a balloon for
either proximal or distal occlusion. e lter may
be either a free wire or xed wire system. Either
way, the tip of the 0.014-inch guidewire is shaped
appropriately to aid access to the internal carotid
artery. Aer crossing the stenosis, the tip of the
guidewire is placed close to the skull base but not
into the intracranial portion of the artery. It is
important to avoid advancing the tip of the guide-
wire any further. e intracranial portion of the
carotid artery is prone to dissection with guide-
wire manipulations. e image intensier posi-
tion is then set, with the tip of the sheath visible
at the lower margin of the view, the bifurcation in
themiddle, and the tip of the guidewire on which
the lter is based located at the upper end of the
eld of view.
Aer the guidewire is placed across the lesion,
the lter is rapidly deployed. e length of the lter
and the location of the stenosis must be taken into
account. Each lter requires an appropriate land-
ing zone, preferably in a straight and nondiseased
artery segment at least 2 cm distal to the loca-
tion intended for the upper end of the stent. is
requirement may also inuence lter selection.
e lesion is predilated with a 3-mm diameter,
monorail-based, 2-cm or 4-cm length balloon.
Prior to specic events, such as predilation, stent
placement, or poststent balloon angioplasty, small
doses of atropine (0.25–0.50 mg each time) or other
vagolytic should be administered intravenously to
prevent or blunt the bradycardic response that may
occur. e duration of the predilation depends on
the appearance and behavior of the balloon but is
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Carotid bifurcation stent placement 285
usually kept as short as possible. e predilation
balloon is inated only once and the ination time
varies depending on the lesion. e purpose of pre-
dilation is to create a safe tract for the stent deliv-
ery catheter. Some operators practice “primary
stenting” without predilation on a regular basis.
However, with any signicant stenosis, a 6-Fr stent
delivery catheter will have a dottering eect on the
lesion unless predilation is performed.
Carotid bifurcation lesions may be treated with
any one of the variety of self-expanding stents that
are available for use in this position. e stents
vary from 2 cm to 4 cm in length. e stents may
be open cell or closed cell. Most available stents
are constructed of nitinol, may be tapered or tube
structure, and vary from 6 mm to 10 mm in diam-
eter. e stent diameter is selected based on the
largest diameter that must be tted to the stent,
usually that of the common carotid artery.
e self-expanding stent is deployed using
road mapping. It is postdilated with a 5 mm ×
20mm balloon over a 0.014-inch wire, depending
on the size of the internal carotid artery. is is
usually easily performed by placing the balloon
in the location where any residual stenosis is seen
to be crimping the stent. A 5-mm balloon percu-
taneous transluminal angioplasty (PTA) is oen
adequate; rarely is a 5.5- or 6-mm PTA required
poststent deployment. A mild or even moderate
residual stenosis may be acceptable, as the self-
expanding stents continue to expand with time.
e risks of overdoing it with poststent balloon
dilation include embolization of plaque contents,
severe bradycardia and hypotension, balloon
rupture, and, very rarely, vessel rupture. e bal-
loon used for poststent PTA is always maintained
within the stent and does not extend to the native
artery. is is usually simple since carotid bifur-
cation lesions are focal and the artery proximal
and distal to the lesion tends to be healthier and
of nominal diameter. Nominal pressure is used to
fully expand the balloon and the stent, and it is
not kept inated any longer than necessary. High
pressures are not used. In the majority of cases,
the stent is placed across the bifurcation into the
common carotid artery, crossing the origin of the
external carotid artery.
Occasionally, with poststent angiography, some
ow of contrast is visible outside the stent prole
and into an ulcer. No attempt should be made to
obliterate this by using larger balloons or higher
pressures as this almost always smooths out in the
ensuing weeks and is usually of no consequence.
ere should also be ow of contrast outside the
stent at the location of the origin of the external
carotid artery. Patients with >2-cm long carotid
lesions, dense calcication (seen on plain uoro-
scopic images), and large ulcerated plaques are at
higher risk for complications of CAS placement.
Tortuosity of the common carotid artery, bifur-
cation, or, more commonly, the distal internal
carotid artery may be challenging to manage dur-
ing CAS placement. Tortuous inow causes prob-
lems in creating and maintaining a safe and stable
access. Kinks and bends near the lesion and in the
distal internal carotid artery may pose a problem
with stent implants. As the carotid bifurcation
lesion narrows and plaque thickens and hardens,
it frequently leads to a lengthening of the segment
where the disease is worst. Consequently, at the
location where the lesion ends and the artery is
so, there is oen an eerent turn out of the lesion
that is quite angulated or even kinked. Tortuosity
cannot be removed, only transferred to another
location. As a stent is placed that partially straight-
ens a curved or kinked segment, another segment
juxtaposed to the stented location usually becomes
more tortuous. Deploy stents across bends only if
they are isolated and only when necessary. Avoid
placing the distal end of the stent into kinks and
tortuosities of the internal carotid artery if more
than a single bend is noted. A very tortuous inter-
nal carotid artery should be considered a relative
contraindication for CAS placement.
e lter is removed only aer an arteriogram
has conrmed forward ow through the lter and
no lling defect in the stent or lter. If there is slow
ow or a large amount of debris in the lter, con-
sider using an over-the-wire aspiration catheter to
remove this material. e lter is removed and nal
angiograms are acquired in the projection that had
demonstrated the maximum stenosis. Attention
is paid to the internal carotid artery immediately
cephalad to the stent. Spasm in this segment may
be encountered. e best treatment for inter-
nal carotid artery spasm is to nish the case and
remove the distal protection device. A small dose
of intra-arterial nitroglycerine (50–100 mcg) is
directly administered into the artery. Post-CAS
placement intracranial angiograms are obtained
by many operators as a routine. e sheath is then
removed.
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286 Brachiocephalic interventions
Patients are monitored overnight for cardiac
and neurologic problems. It is not uncommon,
especially in patients with a history of coronary
artery disease, to have a heightened response to
carotid sinus distension. It may require inotropic
support for a time before the carotid sinus adapts
to the radial force of the self-expanding stents.
Avoiding extreme oversizing of the stents helps
to decrease the incidence of post-CAS placement
bradycardia and hypotension. e presence of sig-
nicant hypotension in the absence of bradycardia
is unusual in the immediate postprocedure period;
it is worth emphasizing that other causes (e.g., ret-
roperitoneal bleed related to access site problems)
should also be excluded as the cause. Medications
include aspirin (325 mg each day indenitely)
and clopidogrel (75 mg each day for 1 month).
Follow-up includes duplex scan at intervals, as is
performed aer carotid endarterectomy.
OPEN CELL, CLOSED CELL, AND
MESH COVERED CAROTID STENTS
(
FIGURE21.5)
Both open cell stents and closed cell stents are
available for treatment of carotid bifurcation ste-
nosis. Self-expanding nitinol stents can be viewed
as a series of rings with an oscillating pattern,
which are connected together to form a wire mesh
tube. Open cell stents have connections between
only some of the rings that the stent comprises.
is allows the open cell stent to be signicantly
more exible than other stents. It also means that
the cells or openings of the stent are signicantly
larger than closed cell stents. When an open cell
stent goes around a tortuous segment, some of
the cells on the outside curvature of the bend will
likely be quite large in comparison to the usual size
of the cell if the stent is maintained in a straight
position. Closed cell stents provide more outward
force and crush resistance. ey are usually easier
to visualize uoroscopically because they contain
more metal. At each of the apices of the wire cross-
ings, the rings are typically connected. is leads
to much smaller cells and much more metal cover-
age of the lesion.
ere is some data to suggest that closed cell
stents could provide better results, especially in
symptomatic patients, by providing more metal
coverage of the carotid lesion. is may permit
fewer emboli and provide better scaolding of the
lesion. Most of the data that suggest this possibil-
ity are nonrandomized, so may suer from patient
and lesion selection bias. Nevertheless, there is a
common sense idea that more lesion coverage
is better, and there is no evidence to suggest that
closed cell stents are associated with more resteno-
sis than open cell stents.
Taking that concept a step further is the idea of
a mesh covered carotid stent that would make the
A B C
Fig. 21.5 Relative differences between open cell, closed cell, and mesh covered carotid stents.
(A)Design of a typical open cell stent. The stent is made of nitinol rings. The rings are bridged over
every few oscillations. This pattern of connection provides more flexibility but also leaves larger
spaces between the stent struts. (B) Design of a typical closed cell stent. The separate rings of nitinol
are connected at every possible juncture. This creates better outward force and crush resistance
and better visibility due to the increased amount of metal. However, these stents are not as flexible.
Because there is more metal and the cells are smaller, closed cell stents provide more scaffolding
and more coverage of the lesion. (C ) Mesh covered stent. The backbone is typically a very open cell,
nitinol frame covered by a mesh. This creates much smaller pores and much more extensive lesion
coverage. The mesh may be constructed of nitinol, PET, or PTFE.
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Distal and proximal protection devices for transfemoral carotid stenting 287
spaces in the coverage even smaller. Several dier-
ent mesh covered carotid stents are in clinical tri-
als. e mesh may consist of nitinol, polyethylene
terephthalate (PET), or polytetrauoroethylene
(PTFE). e theoretical advantage would be to
provide the smallest possible cells through which
an embolus could occur and still maintain the
patency of the external carotid artery. e poten-
tial disadvantages are a slightly larger caliber deliv-
ery of the mesh covered stent and also the potential
that the mesh will take up some of the lumen and
result in a higher degree of residual stenosis or
increased recurrent stenosis. Data so far show that
the external carotid artery generally maintains
its patency. e mesh covered stent may make a
signicant contribution to endovascular manage-
ment of carotid disease in the future.
DISTAL AND PROXIMAL
PROTECTION DEVICES FOR
TRANSFEMORAL CAROTID
STENTING (
FIGURE 21.6)
Most of the protection devices in the carotid stent
trials so far have been performed using distal lters
as the cerebral protection device. ere are several
dierent lters that have been approved for use and
been well studied. Many resemble an umbrella or
a badminton birdie. ese lters are mounted on
a wire and must be placed across the lesion prior
to establishing protection. Filters typically com-
prise of a nitinol scaolding and a porous cover-
ing over the “top” of the umbrella. When a lter
is unsheathed, the lter opens. e lter must be
placed in a segment distal to the lesion. erefore, a
A B C
Fig. 21.6 Methods of cerebral protection for transfemoral carotid stent placement. (A) Distal
protection filter. The filter is mounted on a wire. The filter must cross the lesion in its constrained
state and then be unsheathed and opened in the distal internal carotid artery distal to the lesion. This
requires a filter landing zone. The filter must be opposed to the wall for it to work as well as possible.
The filter illustrated is a fixed wire filter because it is mounted directly on the wire. If the wire moves,
the filter moves. (See text for description of free wire systems.) (B) Distal occlusion balloon. The
balloon is mounted on a wire. The wire is actually a hypotube, which can be used to inflate the balloon
and stop antegrade flow into the internal carotid artery distal to the lesion. The crossing profile of this
device is typically less than that of a constrained filter. This is not commonly used in the US but is used
in many countries. (C) Mo.Ma
™
Ultra proximal protection device. The sheath is slightly larger at 8-Fr.
Ithas a balloon mounted on its tip, which can be inflated to stop flow from the common carotid artery
and into the bifurcation. There is also a catheter that connects to a smaller balloon, which is used
to occlude the external carotid artery. The remaining lumen of the sheath is then used to perform
carotid angioplasty and stenting. The bifurcation is aspirated before flow is restored into the internal
carotid artery.
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288 Brachiocephalic interventions
relatively stra ight segment of artery must be present
for a lter landing zone. e lter must be placed
far enough distal to the lesion that the stent can be
placed with its superior end extending beyond the
lesion into healthier distal artery without encoun-
tering the lter. If the artery distal to the lesion is
very tortuous, it may not be possible to place the
lter. Once the lter is in place, the goal is not to
move it during the time that the angioplasty and
stenting of the carotid lesion is being performed.
Aer the lesion has been treated, a lter capture
catheter is passed through the fully opened carotid
stent to capture the lter. When the lter is cap-
tured, if there is signicant debris within the lter,
an attempt is made to close the nitinol loop that
supports the lter without squeezing the entire l-
ter into the capture catheter. is provides some
room for debris in the lter to prevent it from being
released into the circulation. Spasm can occur at
the location where the lter is resting just distal
to the lesion, and the operator should be ready to
administer a vasodilator if this is the case. If the
lter is full, an aspiration catheter can be used on
the wire prior to lter retrieval to remove some of
the debris from the area. is is especially the case
if the lter is so full that ow through it is impeded.
Filters may be xed to the wire (xed wire sys-
tem) or may be oating on the wire (free wire sys-
tem). Either system can be used in most carotid
stent procedures. With a xed wire system, when-
ever the wire moves, the lter also moves. e free
wire system permits the wire to cross and the lter
to be advanced over it. is may have an advantage
over the xed wire system in patients with tortuos-
ity to facilitate lter crossing. Free wire systems are
preferred in the lower extremity where more wire
movement is expected. Some of the free wire sys-
tems that are used for distal protection are demon-
strated in Chapter 20, Figure 20.14.
A Mo.Ma
™
Ultra proximal protection device
includes a common carotid artery occlusion bal-
loon on the tip of the sheath and a catheter in the
external carotid artery. e proximal occlusion
balloon on the tip of the sheath stops forward ow
through the common carotid artery. e exter-
nal carotid artery occlusion balloon prevents ow
coming in a reverse manner from the external
carotid to the internal carotid artery. Aer the
external carotid artery balloon and proximal com-
mon carotid artery occlusion balloon are in place,
ow through the carotid bifurcation is stopped.
Under cessation of ow, the carotid stent is placed.
Aer the stent is placed, the carotid bifurcation
and the stented segment are aspirated of debris.
When this is done, the balloons are released and
ow is restored.
TRANSCERVICAL APPROACH
TO CAROTID STENTING
(
FIGURES21.7–21.9)
Transcarotid artery revascularization (TCAR)
provides an alternative method of access and pro-
tection for carotid artery stenting. TCAR oers
the potential of avoiding the aortic arch, establish-
ing protection prior to wire crossing, and more
ecient particle capture during the carotid stent
procedure.
Particle capture by distal lters appears to be
inadequate. is is based on a number of MRI
studies of the brain, which show that the appear-
ance of new cerebral white matter lesions aer
transfemoral, distal lter-mediated carotid stent-
ing is substantially more than is seen with carotid
endarterectomy. In addition, studies of TCAR have
shown that a signicant minority of the strokes
associated with the procedure occur in the con-
tralateral hemisphere. During proximal protection
with common carotid artery balloon occlusion
there are also strokes that occur in the contra-
lateral hemisphere. is suggests that the arch of
the aorta may be a signicant source of strokes.
In addition, both of these protection maneuvers
require signicant manipulation of the bifurcation
prior to establishing protection.
In the TCAR approach, the proximal common
carotid artery is accessed through a n open cutdown
and proximal protection is achieved with a clamp
on the common carotid artery and a reversed ow
circuit with ow into the femoral vein. e pro-
cedure may be performed under local or general
anesthesia. A short, approximately 1-inch (2.5cm)
incision is performed, usually transverse and just
superior to the clavicle. e dissection is car-
ried down through the platysma and in between
the sternal head and the clavicular head of the
sternocleidomastoid muscle. It is usually best to
dissec t between the muscle heads rat her than divide
them. e jugular vein is identied and retracted
laterally. e common carotid artery is usually just
deep to the jug ular vein. e common ca rotid artery
is identied and dissected out. A 5-0 prolene
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Transcervical approach to carotid stenting 289
purse-string suture is placed along the anterior
wall of the artery at the location where the sheath
access will be placed. A small self-retaining retrac-
tor is usually helpful. Anatomic specications
require that the distance between the clavicle and
the carotid bifurcation lesion should be 5 cm or
more. If the patient has a very thick neck or a deep
neck, a distance of more than 5 cm is better.
A sheath is placed in the femoral vein, usually on
the side contralateral to the carotid lesion to make
logistics simpler. A reversed ow circuit is created
between the common carotid artery and the femo-
ral vein. A micropuncture needle is placed in the
middle of the location of the purse-string suture in
the proximal common carotid artery, and a micro-
puncture guidewire is inserted, which is measured
prior to insertion to avoid encountering the bifur-
cation. A micropuncture catheter is inserted into
the artery for 1–2 cm and an arteriogram obtained.
If the runway to the lesion is quite short, the wire
is advanced into the external carotid artery and
a short specially designed exchange guidewire
placed in the external carotid artery. If the dis-
tance to the lesion is longer (i.e., more than 5 cm
from the puncture site), a sti exchange wire with
the atraumatic tip can be placed in the distal com-
mon carotid artery proximal to the lesion. Aspe-
cially designed sheath is inserted over the short
exchange wire. e sheath is larger (8-Fr) so that a
reversed ow circuit can be achieved while bifur-
cation stenting is being performed. e sheath has
an external stopper on its sha so that the tip of
the sheath only goes approximately 2 cm into the
arter y.
Aer the sheath is inserted, the exchange wire
and dilator are removed. e sheath is secured
in place. is must be performed carefully since
the sheath tip is only inside the artery by 2 cm.
A B C
Fig. 21.7 Transcervical exposure of the proximal common carotid artery for a TCAR procedure.
(A) A short transcervical incision is created between the sternal head and clavicular head of the
sternocleidomastoid muscle. The patient is positioned such that the neck is extended and the
head turned to the opposite side. The position of the incision is confirmed, using ultrasound,
prior to making the incision. An ultrasound probe is placed over the area in question to find the
shortest route to the common carotid artery. Almost always, this is between the two heads of the
sternocleidomastoid muscle. (B) After the transverse incision is created, the platysma is divided.
The muscle bellies of the clavicular head and the sternal head of the sternocleidomastoid muscle
are identified. The space in between the muscles is developed. The clavicular head of the muscle is
retracted laterally and the jugular vein typically lies directly over the common carotid artery. Care
must be taken to avoid vagus nerve injury, as it may be located anywhere within the carotid sheath.
Itis almost always deep to the area of dissection. The vein is retracted laterally to expose the
common carotid artery. (C) The common carotid artery is dissected free of surrounding tissue and
looped. A 5-0 prolene purse-string or U-shaped suture is placed in the anterior wall of the common
carotid artery where the sheath will be placed.
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290 Brachiocephalic interventions
esheath tip has a slightly curved shape to it so
that it conforms easily to the shape of the carotid
artery. Aer the sheath has been secured, the
reversed ow circuit is established. e reversed
ow circuit has a ow modulator that allows ow to
be regulated (stopped ow, slow ow, or highow)
at the press of a button. e circuit also contains a
lter that can be examined aer the procedure for
any particulate.
Heparin is administered prior to accessing the
carotid artery. e ACT is elevated to 250 seconds
or more. Aer the arterial sheath is placed and the
A B
C
D
Fig. 21.8 Establishment of a reversed flow circuit with common carotid artery clamping.
(A)Acontralateral femoral vein sheath is placed. (B) A micropuncture needle is inserted 1–2 mm
into the artery at the center of the purse-string suture on the anterior wall of the common carotid
artery. The micropuncture guidewire is advanced so that it extends into the artery only 2–3 cm.
Themicropuncture sheath is passed over the wire and an arteriogram obtained that demonstrates
the location of the bifurcation and also the distance to the lesion. An exchange wire is inserted either
into the external carotid artery or the distal common carotid artery. The sheath is advanced over
the exchange wire. (C) From the common carotid artery sheath, a reversed flow circuit is placed.
Thecircuit includes a flow modulator, which allows stopped flow, slow flow, or high flow. Distal to the
flow modulator there is a filter, which will contain any debris that is released and removed from the
carotid bifurcation. The flow circuit is plugged into the venous sheath and reversed flow is confirmed.
(D)When the procedure is ready to be performed, a proximal common carotid artery clamp is placed.
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Transcervical approach to carotid stenting 291
reversed ow circuit is in place, reversal of ow in
the circuit is conrmed. e proximal common
carotid artery clamp is then placed, proximal to
the sheath. Oxygenated blood from collaterals is
entrained to serve the ipsilateral hemisphere. is
also allows very thorough removal of debris during
the stenting process.
If the lesion is very near the tip of the sheath,
a 0.014-inch atraumatic guidewire is placed across
the lesion. A standard predilation angioplasty is
performed and a carotid stent placed. A stent sys-
tem on a shorter sha has been approved by the
FDA, and this can also be used to improve the ease
of use of the procedure. With each angiogram,
the ow can be stopped. e contrast is gently
administered and the bifurcation visualized. By
releasing the stop button immediately aer visu-
alizing the lesion, the injected contrast material
can be removed by ow reversal. Aer the stent is
placed, it is common to permit reversed ow for
a period of time aerward. is allows for more
complete ushing and removal of particulate. e
transcervical approach to CAS placement has the
same hemodynamic eects as transfemoral stent-
ing and is oen followed by hypotension and/or
bradycardia.
A B C D
Fig. 21.9 Carotid stent placement using a TCAR approach. (A) After the proximal common carotid
artery clamp is placed, flow reversal in the circuit is confirmed. Flow reversal brings oxygenated blood
into the ipsilateral hemisphere through collaterals using the process of entrainment. At this point it
is safer to place a guidewire across the internal carotid artery stenosis since flow through the carotid
artery is reversed. (B) While the flow is reversed, a predilation balloon is inserted to create a space for
stent placement. The same hemodynamic effects of any angioplasty and stenting procedure of the
carotid bifurcation should be expected, including hypotension and bradycardia. (C) The carotid stent
is placed through the sheath and into the usual position, with continuation of reversed flow. (D)After
stent placement, the wire is removed and flow reversal maintained for a few minutes. After that
the common carotid artery clamp is removed, the sheath may be safely removed, and the common
carotid artery purse-string suture is tied.
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292 Brachiocephalic interventions
RETROGRADE APPROACH TO THE
COMMON CAROTID ARTERY
Common carotid artery lesions may also be
approached retrograde, through open exposure
of the mid- or distal common carotid artery. is
approach is usually best in the following circum-
stances: angulated arch anatomy or arch disease
that is not favorable for an antegrade approach; or
a combined carotid bifurcation lesion that requires
simultaneous endarterectomy (Figure 21.10). e
two key factors for consideration in this approach
are the very short working room between the
access and the lesion and the need to clamp the
carotid for a short period of time without options
for a shunt.
Common carotid artery exposure is performed
through a short incision and the artery is looped.
Heparin is administered. It is usually best to place
a transfemoral pigtail catheter in the arch of the
aorta for arteriography, even if the intervention is
to be performed retrograde. is is because retro-
grade carotid arteriography is suboptimal at delin-
eating the origin of the artery, especially in the
setting of an orice lesion. e image intensier
is placed in the LAO position to best demonstrate
the separation between the common carotid or
innominate arteries and the other arch branches.
In situations where open exposure is performed
for treatment of an isolated arch branch lesion, a
5-0 Prolene
®
purse-string suture is placed in the
anterior surface of the common carotid artery.
e artery is punctured as distally along the com-
mon carotid artery as possible but in a location
that allows clamping and avoids any bifurcation
disease. is helps to maximize working room
between the access site and the lesion. e approx-
imate distance can be measured on pretreatment
CTA and an appropriate short sheath with a radi-
opaque tip can be selected. A short micropuncture
needle (4-cm length) with a directable guidewire is
usefu l here. e wire is inserted t hrough the needle,
and uoroscopy is initiated immediately since the
lesion will be encountered within a few centime-
ters. Aer the guidewire is across the lesion, steer
it into the descending aorta. e natural tendency
is for the guidewire to direct itself into the ascend-
ing aorta. e ascending aorta can only accom-
modate a short length of wire before it encounters
the aortic valve. A short, bent tip selective catheter,
such as a 40-cm long Kumpe catheter, is used to
direct the guidewire into the descending aorta.
Avery short access sheath, preferably 8 cm or less,
is placed in the retrograde position. A retrograde
arteriogram is obtained. If the proximal common
carotid artery lesion is preocclusive or critical in
severity, it may not be possible to accurately iden-
tify the origin of the artery using a retrograde
contrast injection. Alternatively, consider an arch
aortogram through a transfemoral pigtail catheter.
e appropriate balloon and stent are selected and
placed. e diameter of the common carotid artery
can be measured on preoperative imaging studies
and the appropriately sized premounted, balloon-
expandable stent is prepared ready for insertion.
e distal common carotid artery may be clamped
during balloon angioplasty and stent placement as
a form of distal protection. e artery is ushed
and repaired aer intervention.
A hybrid procedure that combines simultane-
ous inow stenting of the common carotid artery
and carotid bifurcation endarterectomy is shown
in Figure 21.10. Some additional maneuvers
include the following steps. e carotid bifurca-
tion is exposed and prepared as usual for endar-
terectomy. Aer anticoagulation, the internal and
external carotid arteries are clamped. e micro-
puncture needle is placed in the common carotid
artery at the location where the proximal end of
the carotid arteriotomy is intended. e common
carotid stent is placed as described in the section
above. Aer completion arteriography, the guide-
wire is removed. e sheath is removed and the
common carotid artery immediately clamped
proximal to the arteriotomy site. e access site is
used to begin the longitudinal carotid arteriotomy.
Aer the artery has been opened in the usual man-
ner, a shunt may be inserted as needed. e endar-
terectomy is performed in the usual manner.
THE SUBCLAVIAN AND AXILLARY
ARTERIES
Subclavian and axillary artery lesions can be
approached antegrade (femoral artery access) or
retrograde (brachial or radial artery access). e
best candidates for this procedure have symptom-
atic vertebrobasilar insuciency or upper extrem-
ity ischemia and a lesion that does not involve the
origin of the vertebral artery. CTA of the arch is
useful for planning the approach to subclavian
artery lesions. e most commonly treated lesion
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The subclavian and axillary arteries 293
A B C
D E F
Fig. 21.10 Retrograde approach to the common carotid artery and hybrid approach to tandem
carotid lesions. (A) The patient has tandem lesions of the carotid artery, including a proximal
common carotid artery stenosis and a carotid bifurcation stenosis. (B) There is typically only a short
distance between the two lesions. These may be repaired using an open approach (inflow bypass plus
carotid endarterectomy), an endovascular approach (stent placement at the common carotid artery
and the carotid bifurcation), or a hybrid approach (stent placement in the proximal common carotid
artery and carotid endarterectomy). (C) The carotid bifurcation is prepared for open surgery. At the
location where the proximal end of the arteriotomy would usually be located, a needle is placed in a
retrograde direction. (D) The guidewire is placed and a 6-Fr short sheath with a bright tip inserted.
The internal carotid artery is clamped prior to sheath placement. The wire usually extends toward
the aortic valve. If desired, the wire must be directed into the descending aorta to avoid passing it
through the aortic valve. (E) A balloon-expandable stent is placed in the proximal common carotid
ar ter y. (F) The wire is removed. The internal and external carotid artery clamps are left in place. The
sheath is removed and the common carotid artery cross-clamped. The access site is used to initiate a
longitudinal arteriotomy for standard endarterectomy.
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