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404 Technical aspects of treating aortic aneurysms
A
B C
D E
Fig. 28.10 Through-and-through wire. (A) A through-and-through wire is not often required but it can
be the difference between completing a challenging case or not. The patient’s left arm is extended
to the side. The left brachial sheath may be placed percutaneously or through open exposure.
Nitroglycerine may be administered through the sheath in order to prevent spasm of the brachial artery.
(B) A guidewire is advanced retrograde through the axillary and subclavian vessels. The guidewire tends
to direct itself into the ascending aorta. (C) A hook-shaped catheter is advanced over the wire and into
the distal arch. The catheter is used to direct the guidewire into the descending aorta. (D) The catheter
is advanced into the descending aorta. A long, angle tip catheter is better in this position than the hook-
shaped catheter that was used for directing the wire into the descending aorta. (E) A femoral sheath has
been placed and a catheter and guidewire advanced through it. (Continued)
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Balloon angioplasty after endograft placement 405
slowly as the angles in the platform oen shi
and the wire may try to fall out of the contralat-
eral gate. Once the Glidewire
®
is advanced into
the body of the aortic gra, the catheter can usu-
ally be advanced over it. Sometimes, the catheter
catches on the lip or rim of the contralateral gate.
e catheter in this position has minimal support
and care must be taken while advancing it; some-
times, twisting the catheter helps. If this concept of
an angulated sheath tip and an angulated catheter
together is not helpful, an articulating sheath can
be used. An articulating sheath only gives curva-
ture in one direction, but the degree of curvature
can be controlled and an angled catheter can be
used through it, if necessary. If all of these maneu-
vers fail, consider upper extremity access. Coming
from the proximal direction, it is usually a straight
trajectory. Once the guidewire has come out of the
contralateral gate, it must be snared and pulled out
of the femoral sheath. As the wire is retracted from
the femoral sheath, it must be fed in at the brachial
level. e proximal le subclavian artery must be
protected with a catheter or sheath so that injury
does not occur to this vessel.
BALLOON ANGIOPLASTY AFTER
ENDOGRAFT PLACEMENT
Aer the endogra has been placed, a compliant
shaping balloon is used to seal both ends of the
gra and also the overlapping points. e bal-
loon must not be overinated. Visualization of
the balloon under uoroscopy demonstrates the
shoulders of the balloon becoming square. At the
proximal end, it is best to have a substantial length
of the balloon proximal to the gra. If the balloon
is placed too distal, when it opens it may form a
pear shape, the lower end of which could prolapse
distal to the neck into the wider aneurysm. is
tends to pull the gra distally. All of the connect-
ing points for the friction seal between gra seg-
ments should also be treated with angioplasty. If
there is any residual stenosis at the bifurcation
or in the proximal common iliac arteries, kissing
angioplasty balloons of 8 mm, 10 mm, or 12 mm
in diameter should be considered. If a completion
angiogram shows an endoleak, consider repeat
angioplasty of the neck and the endogra ends and
components.
F G H
Fig. 28.10 (Continued) Through-and-through wire. (F) A snare is advanced through the femoral
sheath. (G) The proximally approaching guidewire is captured through the snare placed in the femoral
sheath. (H) The guidewire is withdrawn from the femoral sheath. As the wire is pulled into the brachial
artery and out of the femoral artery, the proximal subclavian artery is protected using a catheter to
prevent guidewire injury to the artery. The brachial wire must be manually fed into the brachial artery
sheath and not dragged. As long as the through-and-through wire is in place, a catheter or sheath
must be maintained over the wire to prevent it from injuring the proximal subclavian artery.
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406 Technical aspects of treating aortic aneurysms
A
C
D
B
Fig. 28.11 Cannulating the contralateral gate. (A) The body of the
endograft has been placed and the contralateral gate exposed. The
contralateral femoral sheath access is maintained in the aneurysm sac.
Asimple angle tip catheter is used and a Glidewire
®
is advanced into the
contralateral gate. (B)If additional angulation is required, a 6-Fr angle
tip sheath can be advanced further into the aneurysm sac. The combi-
nation of the curvature at the tip of the sheath, the angulated catheter,
and the curvature at the tip of the Glidewire
®
can be used to help can-
nulate the contralateral gate. (C)If additional angulation is required to
cannulate the contralateral gate, an articulating sheath of 6.5-Fr caliber
can be inserted and used to direct the tip of the sheath and guidewire
into the contralateral gate. The tip of the articulating sheath can be
deflected and controlled by the operator through rotation of the handle
mechanism. (D)Ifthese maneuvers fail, which rarely occurs, a wire can
be placed approximately from the brachial artery and advanced into the
contralateral gate. The wire is then ensnared and brought out through
the femoral sheath.
POSTPLACEMENT STENTING OF
ILIAC ARTERIES
Iliac stent placement aer aortic endogra place-
ment is rarely required. Nevertheless, injuries may
occur, especially if the patient had unfavorable
iliac anatomy requiring treatment or manipula-
tion. Temporary straightening of the arteries with
sti exchange wires and placement of large cali-
ber sheaths can cause dissection and also could
disrupt previously identied occlusive lesions
(Figure 28.12). Completion imaging of the gra
limbs and iliac access vessels is routine. is can
be performed with a hand injection of contrast
through the side arm of the femoral sheath. An
oblique view with caudocranial angulation may
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Management of a difficult aortic neck 407
be required. It is usually best to withdraw the
sheath as far as possible so that there will not be
any articial stiening of the iliac artery. Control
of the vessel can be maintained with a so cath-
eter or wire extending through the iliac artery.
Ifan injury to the iliac vessels is identied, there is
little added risk of stent placement, usually with a
self- expanding nitinol of 8–12 mm in diameter. If
the vessel is tortuous, no more length of the artery
should be covered than is absolutely required.
MANAGEMENT OF A DIFFICULT
AORTIC NECK
ere are several ways in which an aortic neck may
be considered dicult. An aortic neck may be tor-
tuous, it may be a very short neck, it may contain
thrombus, or it may be signicantly calcied. If
there is a combination of these factors, the chal-
lenge may be even greater. Ultimately, the goal is
to obtain a seal in this area. ere are a variety of
ways to manage this from an endovascular stand-
point. ese include aortic cus, snorkel gras
to allow for a longer proximal sealing zone, endo
staples in order to provide greater xation of the
gra to the wall, Palmaz™ stents, and occasion-
ally aortic cus if the initial gra placement is
distal to the desired location. Note that this is the
subject of ongoing debate. Some of these patients
may be better treated with fenestrated aortic gras
with specic aortic branch gras, but the anatomic
requirements for existing gras are fairly narrow.
Another school of thought is that these patients are
best treated with open repair for long-term success
and durability.
e purpose of a snorkel gra is to lengthen the
sealing zone of the aortic endogra (Figure 28.13).
e snorkel serves to bring perfusion to the most
inferior, and yet still signicant, aortic branch.
erefore, a snorkel gra is typically placed in the
most inferior renal artery. is permits the aortic
gra to reach a more proximal location for sealing,
A
B C
Fig. 28.12 Checking the iliac arteries after stent–graft placement. (A) A stent–graft limb has been
placed and the end of the stent–graft is located at the iliac bifurcation. Because of tortuosity of the
iliac artery, with sheath and wire placement, the iliac artery has become corrugated and its actual flow
surface cannot be evaluated. (B) A soft catheter or soft wire is used to maintain access through the
iliac artery, and the sheath is partly withdrawn. This permits the extra iliac artery to take some of its
normal shape. (C) With an oblique view, dissection may be identified in the external iliac artery that
may require repair.
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408 Technical aspects of treating aortic aneurysms
A B
C D
E F
Fig. 28.13 Snorkel graft placement. (A) An infraclavicular incision is performed and the axillary artery
exposed. (B) The left axillary artery is encircled with the dacron tape. A micropuncture needle is used
to initiate the access and a sheath is placed. (C) The wire, typically a Rosen wire, is advanced from
the axillary artery access to the renal artery intended for snorkel graft placement. (D) A long 6- or
7-Fr sheath is placed over the wire so that the tip of the sheath is advanced into the renal artery. Care
must be taken to avoid advancing the wire or sheath too far into the renal artery and risking injury
to the parenchyma. (E) The femoral sheath delivering the body and limb of the aortic endograft is
advanced. Deployment at the desired location is initiated. (F) The body of the aortic endograft and
the snorkel graft are fully deployed at the same time. Postplacement balloon angioplasty is also per-
formed at the same time, with an angioplasty balloon in the snorkel graft and a shaping balloon in the
aortic endograft. Depending on the type of graft used for the snorkel, it may require reinforcement
with a bare metal nitinol stent.
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Management of a difficult aortic neck 409
up to the level of the more proximally placed renal
artery. At times, it may be more appropriate to
include the bilateral renal arteries with snorkels. If
more than two side branches or snorkels are placed,
patency is diminished. Snorkel gras are not use-
ful for small renal arteries (<5 mm in diameter).
Access for a snorkel placement is typically
obtained through open exposure of the axillary
artery, usually on the patient’s le side. A trans-
verse infraclavicular incision is performed. e
muscle is split. e axillary vein, which is usually a
little bit anterior and superior to the artery, is dis-
sected away from the axillary artery. If the patient
has undergone a previous le internal mammary
artery gra to the coronary vasculature, the axil-
lary exposure is usually distal to this. However, the
operator should be aware if this is the case, since it
may aect the plan for clamping the artery. Aloop
is placed around the artery with dacron tape for
control. An axillary artery conduit may also be
used. A 6-Fr or 7-Fr sheath is advanced into the
suprarenal aorta. e renal artery in question is
cannulated. A Rosen guidewire is placed within
the renal artery.
e sheath is advanced so that the sheath and
the stent are all the way into the renal artery.
An appropriately sized covered stent, either a
Viabahn™, an atrium Icast balloon-expandable
stent, or a Gore
®
Viabahn® VBX, is used. e
sheath length must be adjusted based on the site
of insertion. Usually, a 65-cm or 70-cm sheath is
adequate, whether the access site is at the brachial
artery or the axillary artery. e dilator for the
sheath is removed and the balloon-expandable or
self-expanding stent is advanced so that it is still
within the sheath and also within the renal artery.
e aortic stent–gra is advanced. e gra can
then be deployed so that the upper edge of the
material extends to the more proximal of the
two renal arteries. If both renal arteries are being
treated with snorkels, the gra can be placed more
proximally up to the inferior aspect of the superior
mesenteric artery.
e aortic gra and the snorkel gra are placed
and opened simultaneously. e snorkel gra is
ideally placed 2–3 cm into the branch and extends
to 3 cm proximal to the proximal end of the aortic
gra. is takes some preoperative planning and
depends on the available lengths of the desired
branch gras. Both the gra at the neck of the
aneurysm and the renal artery branch gra are
treated with balloon angioplasty at the same time.
If a self-expanding nitinol stent–gra is used for
the renal artery branch gra, it is subsequently
reinforced with a self-expanding bare metal niti-
nol stent to give the renal stent more outward
force.
e snorkel gra will cause the formation of
a gutter in between the edges of the stent–gra
where the aortic gra may not have a complete seal
with the wall of the aorta. e longer this “gutter”
segment is and the fewer of them there are, the bet-
ter chance there is of an acceptable seal and a good
long-term result. Endo staples may also be used to
staple the aortic gra to the aortic wall at the edges
of the snorkel gra.
A snorkel gra may also be placed through the
brachial artery, especially in a large-sized person if
the brachia l artery is at least 4 –5 mm and the sheath
is 6- or 7-Fr. If multiple snorkels are required, the
conduit is placed on the axillary artery and each
of the required 6- or 7-Fr sheaths can be advanced
through the same conduit. Each one should be
labeled as to the gra that it contains. e length of
the snorkel gras are usually 10 cm or 15 cm, and a
6-mm diameter gra is a common size.
Endo staples may also be used to improve xa-
tion of the neck of the aortic gra. ese are placed
through an articulating sheath. e sheath can be
angled at 90° so that the tip sits ush with the gra
as it points to the wall of the aorta. With the press
of a button, the automated staple delivery extends
halfway into the wall of the aorta. If it appears to
be a straight trajectory, a second press of the button
allows completion of the insertion of the staple or
screw through the material and into the wall of the
aorta. e staples appear to be like small screws.
e sheath tip is straightened so that the articu-
lated tip does not drag on the gra. e articulating
sheath is reoriented, recurved, and redeployed and
a new staple can be put into place in a new position.
e ideal placement for a row of endo staples is a
few millimeters from the proximal end of the gra,
followed by a row that is a few millimeters deeper
into the gra. Typically, a row of endo staples is
placed such that there is one staple in each of four
quadrants of the aortic circumference.
A large Palmaz™ stent can also be used to
improve xation (Figure 28.14). is is an older
solution but is one that can manage a type I
endoleak due to an infolding gra, and it is also
able to moderately straighten a tortuous neck. e
https://t.me/med1917
410 Technical aspects of treating aortic aneurysms
Palmaz™ stent has a capability diameter of 25 mm
or 26 mm. e large stent is 5-cm long but is short-
ened to about a half its length on full expansion.
e stent is hand-crimped onto a large balloon. e
delivery sheath is advanced to an area proximal to
the area intended for stent placement. e goal of
the placement is to have approximately half of the
stent in the gra and half of the length extend-
ing proximal to the gra into the aorta. e stent
is placed across the origins of the renal arteries.
A
B
D
E F
C
Fig. 28.14 Palmaz™ stent placement in the aortic neck. (A) A large bore angioplasty balloon is
brought on to the sterile field. (B) A large, 5-cm length, balloon-expandable Palmaz™ stent is hand-
crimped onto the balloon. If the operator has the option, it is usually best to load the stent in a
slightly eccentric way, with the tip of the balloon slightly exposed so that the tip can begin to expand
before the body of the balloon expands. (C) The delivery sheath is advanced to a location proximal
to the location of stent placement. (D) The balloon and mounted stent are advanced to the location
of desired placement. The sheath is only partially withdrawn, so that the stent is exposed but the bal-
loon is well supported by the sheath. (E) The exposed balloon at the tip inflates first and this prevents
the stent from migrating forward. The supporting sheath at the back end of the balloon prevents the
stent from migrating backward. (F) The stent is fully expanded with the sheath in full support at the
base of the balloon.
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Endovascular graft treatment of a ruptured abdominal aortic aneurysm 411
edelivery sheath is typically 12–14-Fr. e stent
is hand-crimped on to the balloon so that the stent
is placed o center toward the hub end of the bal-
loon, rather than toward the tip end. e sheath
is retracted so that the stent just clears the tip of
the sheath. When the balloon begins to inate at its
tip, it traps the stent so that it cannot shoot forward
o the end of the balloon. e stent is prevented
from migrating backwards because the sheath is
there to support it. e stent is then fully inated.
ENDOVASCULAR GRAFT
TREATMENT OF A RUPTURED
ABDOMINAL AORTIC ANEURYSM
Endovascular treatment of a ruptured aneurysm
has become a common approach (Figure 28.15).
Hypotension is permitted preoperatively in an
eort to diminish internal hemorrhage from the
aneurysm. Under local anesthesia, percutaneous
bilateral femoral access is performed. Especially
if the patient is unstable, the percutaneous tech-
nique should be performed. If there is no time for
a pre-close technique, the access can be closed by
performing open exposure of the femoral arteries
at the conclusion of the endovascular gra proce-
dure. e most important thing is to immediately
place a sti exchange wire into the thoracic aorta
and a 12-Fr sheath into the neck of the aneurysm to
obtain proximal control above the aneurysm rup-
ture site. An aortic occlusion balloon is inserted
and placed at or proximal to the renal arteries. e
balloon is inated under uoroscopy to check that
the shoulders begin to square o and to conrm
that the balloon appears stable against the pro-
grade aortic ow. If there has been time to obtain
a CT scan, rapid measurements can be made for
neck diameter and length. If there is doubt about
length, the shorter gra is selected and it is remea-
sured and extended as necessary intraoperatively.
If CT scanning was not possible prior to the
procedure, with the balloon inated proximal to
the neck, it is possible to obtain an angiogram and
assess the location and size of the neck. Contrast
administration through the sheath with the tip of
the sheath in the neck of the aneurysm and inow
occlusion with the aortic balloon will yield some
evidence of the anatomy but will not give precise
measurements. Contralateral femoral access is
performed. A larger sheath is inserted, which will
A C DB
Fig. 28.15 Managing a ruptured abdominal aortic aneurysm with an endovascular technique. (A) A 12-Fr
femoral sheath is placed and advanced into the neck of the aorta, and an occlusion balloon is inflated.
The inflation of the occlusion balloon is visualized under fluoroscopy to ensure that the balloon takes the
appropriate shape and is stable. Vital signs are monitored and if the balloon is correctly located, in most
cases the patient’s stability immediately improves. (B) In order to advance any contralateral wire for
sheath placement, the occlusion balloon must be temporarily deflated. (C) A larger contralateral sheath
is advanced in order to place the aortic endograft. (D) The inflow occlusion balloon must be advanced
to a more proximal level to allow the sheath to deliver the graft. (Continued)
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412 Technical aspects of treating aortic aneurysms
be the delivery sheath for the aortic gra. A14–18-
Fr sheath may be required depending on the endo-
vascular gra that is intended for placement. At
this point in the procedure, the operator will have
developed a sense for the rhythm of the case. If the
patient is unstable and requiring continuous resus-
citation, despite the placement of the occlusion bal-
loon, it is likely a free rupture and each maneuver
may provoke more instability. In other cases, with
permissive hypotension and inow aortic balloon
control, the patient is more stable. is is impor-
tant because each time the thoracic aorta must be
accessed, the aortic balloon must be temporarily
deated, usually to permit the wire to be passed.
e balloon must also be deated to move more
proximally when the endovascular gra is placed
in the aneurysm neck. It is this part of the proce-
dure where good assistance is helpful to allow the
rapid passage of a wire or device and then rapid
reination of the occlusion balloon.
Once there is an exchange guidewire on the con-
tralateral side, the larger sheath may be inserted
into the neck of the aneurysm. e time for gra
deployment is also the time to decide how inow
balloon control will be performed. ere are two
options:
●
e gra body and ipsilateral limb can be fully
deployed. e ipsilateral limb and exchange
wire that runs through it can then be used to
place the aortic balloon in the “true lumen”
proximal to the gra. is is an expedient
method but it has a major disadvantage. e
large sheath through which the main gra
body and ipsilateral limb are deployed also
provides support for the gra in the neck of the
aneurysm. If the anatomy at the neck is at all
unfavorable, the gra may be dislodged distally
before it is fully constructed.
●
e other option is to deploy the main body
and contralateral gate only and leave the large
delivery sheath in place for support. Cannulate
the contralateral gate, advance an exchange
wire and 12-Fr sheath through it, and advance
the aortic occlusion balloon.
With both of these options, the inow aortic
occlusion balloon must be deated for a period of
time before inow control is re-established. e pro-
cess is simpler if the patient is more stable and con-
tinuous balloon ination is not required. Aer the
contralateral gate is cannulated and the contralateral
limb deployed, gra placement can be completed.
E F
Fig. 28.15 (Continued) Managing a ruptured abdominal aortic aneurysm with an endovascular technique.
(E) During endograft placement a decision must be made about how the occlusion balloon will access
the aorta after the initial portion of the endograft is in place. In this example, the contralateral gate has
been cannulated, the 12-Fr sheath has been advanced, and the occlusion balloon has been replaced
proximal to the graft through the true lumen of the graft. The body of the aortic graft is supported by
the larger sheet that was used to deliver it. (F) Another option is to fully deploy the ipsilateral limb and
then use the wire to readvance the occlusion balloon.
https://t.me/med1917
Hybrid procedures associated with aortic disease: Arch debranching 413
Postplacement gra angioplasty is performed.
Special attention is paid to the aneurysm neck and
evaluation of the potential for type I endoleaks. If
there is aortic neck length to be gained proximal to
the gra, aortic cus should be considered. Endo
staples may also be of value in this situation.
HYBRID PROCEDURES ASSOCIATED
WITH AORTIC DISEASE: ARCH
DEBRANCHING
Debranching of the aortic arch branches is oen
required because of the need for coverage at the
respective branch artery origins in order to treat
disease of the arch or proximal descending aorta
and also obtain an acceptable length of seal along
the aortic wall. A bypass gra is usually performed
to accomplish this task and may include some
combination of a le carotid-to-subclavian bypass,
a carotid-to-carotid bypass, or a bypass from the
ascending aorta to the innominate artery. In asso-
ciation with these, if the origins of any of these
branches are covered, they will require occlusion,
usually with occlusion devices or ligation.
e most common of these procedures is
the le carotid-to-subclavian artery bypass
(Figu re28.16). is is because type B aortic dissec-
tion is increasingly being treated with stent–gra
coverage to manage short-term complications,
enhance long-term remodeling, and prevent aneu-
rysm degeneration. Because the pathology of type
B aortic dissection usually initiates at the level of
the le subclavian artery, it is common for this
area to require coverage in order to have gra seal-
ing in healthy aorta proximal to the dissection
site. e le carotid-to-subclavian artery bypass
is best performed by using a transverse supracla-
vicular incision. e proximal le common carotid
artery is exposed. e anterior scalene muscle is
divided. e phrenic nerve is located on the ante-
rior surface of the muscle and must be preserved.
Just posterior to the muscle is the le subclavian
artery. e jugular vein is located slightly anterior
and lateral to the common carotid artery. e gra
is usually tunneled posterior to the jugular vein.
Either anastomosis may be performed rst. Aer
the carotid-to-subclavian bypass has been carried
out, the aortic stent–gra is placed. Lastly, a plug is
A
C
D
B
Fig. 28.16 Hybrid procedures: Carotid-to-subclavian bypass and thoracic stent–graft. (A) A type B
aortic dissection has caused significant damage to the proximal descending aorta. (B) A transverse
supraclavicular incision is performed. (C) The anterior scalene muscle and common carotid artery have
been exposed. (D) The subclavian artery is exposed by removal or division of the anterior scalene
muscle. (Continued)
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