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414 Technical aspects of treating aortic aneurysms
placed in the proximal le subclavian artery. e
proximal le subclavian artery can also be ligated,
but it must be ligated proximal to the origin of the
le vertebral artery. is can be dicult when the
origin of the vertebral artery is quite proximal.
MANAGEMENT OF ENDOLEAKS
AFTER ENDOVASCULAR
ABDOMINAL AORTIC ANEURYSM
REPAIR
Type I endoleak
When a type I endoleak (Figure 28.17) is identi-
ed during the procedure, it should be addressed
at that time. A type I endoleak can be managed
using some of the techniques described earlier
(see “Management of a dicult aortic neck”). If
a type I endoleak is identied at some later time,
aer the operation, the appropriate measurements
and tools can be gathered to raise the proximal
end of the endogra to a more proximal level. is
may require a fenestrated gra or a snorkel gra.
Aortic cus are commonly used when the dis-
tance from the implanted gra to the renal arteries
leaves additional space for coverage. Endo staples
and balloon-expandable stents are other methods
of xation and sealing of the proximal end of the
gra.
Type II endoleak
Type II endoleaks (Figure 28.18) are oen iden-
tied at the time of the procedure. ese are not
E
F
G
H
Fig. 28.16 (Continued) Hybrid procedures: Carotid-to-subclavian bypass and thoracic stent–graft.
(E)Acarotid-to-subclavian artery bypass is performed. The graft is tunneled posterior to the internal
jugular vein. (F) The thoracic aortic stent–graft is inserted through a transfemoral route and placed
at the distal portion of the origin of the left common carotid artery. The endograft covers the origin
of the left subclavian artery. (G) Sheath access is obtained through the left brachial artery. A vessel
occluder is placed at the origin of the left subclavian artery. (H) Occlusion can also be performed
through a transfemoral sheath. In this case, the patient has an aneurysm that does not involve the very
origin of the subclavian artery and it is safe to place a vessel occluder in this manner. This is per-
formed after a carotid-to-subclavian bypass and prior to stent–graft placement.
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Management of endoleaks after endovascular abdominal aortic aneurysm repair 415
typically addressed at the time of the procedure,
except to ensure that there is not some other type
of endoleak present that requires treatment. If a
persistent type II endoleak is associated with aneu-
rysm growth, it oen requires treatment. e best
way to treat a type II endoleak is to treat the inow
and the outow and to obliterate the sac in between.
Transarterial embolization is a useful tool and this
can be performed through collateral routes from
the superior mesenteric artery to the inferior mes-
enteric artery. Lumbar arteries can be reached
through the internal iliac arteries. Laparoscopic
ligation of the inferior mesenteric and/or lum-
bar arteries has also been reported. Obliteration
of the sac may be performed using CT-guided
placement of either a thrombotic agent or glue,
or both, directly into the sac through a le ank
puncture. e sac and some of the branches can
also be reached using a transfemoral/around the
gra approach. A transfemoral arterial puncture
is performed, a 6-Fr sheath placed, and an angle
tip catheter pointed toward the interface between
the iliac gra limb and the artery. AGlidewire
®
is
advanced and passed into the space between the
gra and the artery. e Glidewire
®
is followed
with the catheter until the type II endoleak sac is
entered. e sheath can also be advanced along
the outside of the gra limb, if needed. e sac
is lled with coils, occluders, thrombin, glue, or
a combination of these. e branches feeding the
sac, usually through lumbar arteries, can also be
cannulated and coiled.
Type III endoleak
Type III endoleaks (Figure 28.19) originate from
the location of separation between gra com-
ponents. e more complex an aneurysm repair
and the more remodeling that subsequently takes
place, the more chance that a type III endoleak
could occur. Usually, this is identied in the set-
ting of seemingly sudden growth of the aneurysm.
A
B
C
D
Fig. 28.17 Type I endoleak. (A) An endovascular
graft has been placed in the aorta distal to the
location of the renal arteries. An aortic cuff is
added proximal to the previously placed graft in
order to obtain additional seal between the ori-
gins of the renal arteries in the proximal portion
of the graft. (B) Endo anchors are placed in the
proximal portion of the endograft using delivery
through an articulating sheet. (C) APalmaz™
stent is placed at the proximal segment of the
aortic graft, extending into the aorta above the
graft and crossing over the origins of the renal
arteries. (D) A snorkel graft is added to pro-
vide perfusion to the most distally originating
renal artery and to extend the aortic graft more
proximally to gain more seal. This can also be
performed using a fenestrated graft.
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416 Technical aspects of treating aortic aneurysms
edisconnected components can be cannulated
from proximally or distally, or both. Very oen, the
previously aligned gra segments become severely
misaligned when they become disconnected. It
could be postulated that these same forces that
promoted the separation have also caused signi-
cant misalignment. Aer guidewire crossing, a
catheter is placed followed by a sti exchange wire.
A larger sheath, usually a 12-Fr sheath, is placed
and advanced over the sti exchange wire. e
entire distance is relined with an extending limb
to create as much friction seal as possible.
Type IV endoleak
Type IV endoleaks have become much less
common with newer generation grafts and graft
materials. These typically occur as a result of a
hole in the graft material, with direct flow of
blood out of the graft and into the sac. They
may be difficult to discern from other types
of endoleaks, such as a type II endoleak that is
surrounding a graft limb. Often, the only way
to diagnose a type IV endoleak with certainty is
to perform a retrograde arteriogram of the graft
limb with balloon occlusion of the inf low to the
graft. This permits contrast to flow in high vol-
ume through any breach in the graft material.
Whenever a type IV endoleak is considered, the
operator should be prepared to reline the limbs
with new grafts placed internally. The operator
should also be prepared to treat other types of
endoleaks in case it is something other than a
type IV endoleak.
A
B C
Fig. 28.18 Type II endoleak. (A) Transarterial coiling of the inferior mesenteric artery is performed.
This is typically best accomplished using a telescoping system. A sheath is placed in the origin of the
superior mesenteric artery and a series of catheters and microcatheters are used to cannulatethe
branches of the superior mesenteric artery, which feed the inferior mesenteric artery. Coils are
advanced to the origin of the inferior mesenteric artery and deployed. The same process can be
used to coil the lumbar arteries through the internal iliac artery. (B) Under CT guidance, direct sac
puncture can be performed using a needle placed in the left flank area. The needle is advanced
into an area of identified endoleak and the sac may be obliterated with occluders, coils, thrombotic
agents, glue, or a combination of these. (C) A transfemoral/around the graft approach can be per-
formed as an alternative. The angled catheter is pointed toward the interface between the graft limb
and the artery. The Glidewire
®
is advanced into the potential space between the graft limb and the
artery. Usually, a loop of Glidewire
®
forms at its tip and this can be advanced. The catheter is then
advanced into the type II endoleak sac and the sac may be obliterated. Lumbar branches may also
be cannulated using this approach.
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Management of endoleaks after endovascular abdominal aortic aneurysm repair 417
A
B C
Fig. 28.19 Type III endoleak. (A) In this example, component separation has occurred. The compo-
nent parts are usually significantly misaligned and can be difficult to cannulate. (B) When the proximal
segment is cannulated, the guidewire is advanced and the platform gradually stiffened until a sheath
can be used to cross the breach between the separated components. (C) The entire segment from
the origin of the graft limb and extending well into the iliac artery is relined to create a long-segment
friction seal.
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419
29
Coiling of peripheral aneurysms
COILS
ese devices are designed to occlude blood vessels
in various situations (Figure 29.1). ere are many
dierent scenarios in which coils and/or occlu-
sion devices may be of value. Coiling of a hyper-
vascular tumor is sometimes undertaken prior to
removal. Coiling and/or occlusion of the internal
iliac artery may be performed on one or both sides
prior to abdominal aortic stent–gra placement
to avoid a type I or major type II endoleak. e
internal iliac artery may itself be aneurysmal and
require occlusion. Coiling and occlusion devices
may be required in all sorts of arrangements in
which an aneurysm is being treated. Coiling is also
required whenever there is ow in undesired side
branches. When there is an iatrogenic or traumatic
event, which creates an unwanted leak or commu-
nication between artery and vein, coiling should
be considered. Available coils are delivered using
standard catheters. Larger coils t through either
a standard 4-Fr or 5-Fr angiographic catheter and
are 0.035 inch in diameter, the same as a guidewire
that would be used for that catheter. e smaller
caliber coils for peripheral use t through a micro-
catheter of approximately 2.5-Fr and the coils are
0.018 inch in diameter.
e key to coil embolization is to provide excel-
lent positioning and platform support. One of the
challenges associated with coiling is obtaining
an adequate position of the delivery catheter and
keeping it stable during the coiling process. Even
when the catheter is perfectly positioned for coil
delivery, the act of passing the coil and the pusher
through the catheter may change the catheter posi-
tion. e best way to set up a coiling case is to do
it in a telescoping manner. An example of this
would be to use a 6-Fr sheath and advance the tip
of the sheath as close to the target lesion as pos-
sible. en extend a 5-Fr catheter from beyond
the tip of the sheath; this could be used to enter
the lesion and deliver the coils. Additional levels
of telescoping can also be performed by using a
sheath within a sheath, then a catheter, and then
the coils delivered to that. Another maneuver that
is not oen required is to place a microcatheter
(2.5-Fr) through the 5-Fr angiographic catheter to
approach the lesion. is is performed whenever
the larger caliber diagnostic catheter cannot be
advanced into the lesion as desired.
It is usually best to place the catheter into the
area of treatment a little farther than you think
it needs to be. Everything that happens aer that
tends to put force on the catheter, which makes it
back out. If the catheter retracts or buckles back-
ward a little because it has been stiened slightly
when the coil is advanced, it will still be in an
adequate position. It is usually best to advance
the coil all the way to the end of the catheter and
recheck the position. If the catheter is in too far
at that point, withdraw the catheter partly and
then go ahead and push the coil through. As soon
as the leading end of the coil extends beyond the
end of the catheter, it begins to take its shape. e
catheter can still be pushed or pulled back a bit if
more precise placement is needed. When the rst
coil is placed it should be placed in the deepest
position anticipated. When placing subsequent
coils, the catheter tip may be pushed through the
coils that are already placed, but this is not a reli-
able plan and it is best to place them sequentially
and deliberately if possible. As the coils are being
placed, the tip of the catheter may be used to
tamp down, bunch up, or compact the coils. is
helps to create a good plug to serve as a nidus for
thrombus formation and occlusion.
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420 Coiling of peripheral aneurysms
Several companies make coils. The coil is
straight while it is within the catheter, but as
soon as it reaches an environment that allows it
to expand to a larger diameter, it will immedi-
ately begin to coil. Be sure to match the appro-
priately sized coils with the appropriately sized
delivery catheter. If a 0.018-inch coil is placed
inadvertently into a standard 4- or 5-Fr catheter,
it will begin to coil within the catheter and the
catheter will have to be removed and replaced
because it will not be possible to remove the coil
or push it out. The patient should be anticoagu-
lated during coiling. There are numerous dif-
ferent shapes of coils but there is no clinically
A
B
C
D
E
F
Fig. 29.1 Coils in the peripheral arteries and coil placement. (A) Multiple different configurations of
coils are available. The diameter of the coil should be oversized to the artery that is being treated
to help prevent the coils from migrating after placement. (B) Coils are prepackaged in a metal tube.
The tube has an adapter that is connected to the angiographic catheter that has been placed at the
site intended for coil placement. A guidewire tip is used to advance the coil through the catheter.
(C)Theguidewire is used to push the coil out of the catheter. Immediately on exiting the catheter, the
coil begins to assume its shape. (D) The coil is permitted to wander along a short segment of artery.
(E)The catheter is readvanced and additional coils are placed. (F) The coils are interwoven with each
other. The tip of the catheter can be used to tamp the coils and compress them into a plug.
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Coils 421
apparent advantage of one shape over another
for peripheral indications. The final resting
diameter intended for each coil is the impor-
tant factor. Whether the coil is tapered or a tube
shape, the diameter should be oversized by at
least a couple of millimeters to the artery to be
treated. If the coil is undersized, it will be free
floating when placed in the artery. Some coils
have thrombogenic attachments on them that
are designed to generate thrombus around the
coil. When the coils are tightly packed, they act
as a plug, which will induce thrombus formation
and cause occlusion of the intended artery.
Coiling technique
A sti wire is placed near the target. e patient
is heparinized. A sheath is advanced, usually 5-Fr
or 6-Fr. If an occlusion device other than standard
coils will be required, a larger sheath will be needed
and this must be checked prior to the procedure. If
the target is too delicate to have an exchange guide-
wire go through it, as in the case of a splenic artery
aneurysm, do not overdo it by attempting to get the
sheath tip too close. Place the sheath as far as it will
comfortably go. Place a 5-Fr angiographic catheter
over the sti guidewire and through the sheath. If
the sheath position is inadequate, it can usually be
advanced a bit further toward the target by pushing
it over the combination of the angiographic cath-
eter and the sti guidewire. e 5-Fr angiographic
catheter, usually a simple curve, angle tip catheter,
oen a Glidecath
®
, is advanced to the end of the
exchange guidewire. e exchange guidewire is
removed and a Glidewire
®
placed. e anatomy is
road mapped, usually by administering contrast
through the sheath. e Glidewire
®
is advanced
beyond the site where the coils will be placed and
the Glidecath
®
passed over it. When the catheter
is in the appropriate position, the Glidewire
®
is
removed.
e coils with the intended diameter are pre-
pared one by one since they are packaged sepa-
rately. e metal tube housing the coil is locked
onto the catheter. e stier end or back end of
a Bentson guidewire is used to push the coil out
of its canister and for several centimeters into the
catheter. Once that is accomplished, the guide-
wire is turned around and the so end of the wire
is passed into the catheter and used to deliver
the coil. Although the sti end of the guidewire
could be used to deliver the coil, this may pres-
ent a problem at the treatment end by inappropri-
ately stiening the catheter, and the entire system
may begin to move in an unwanted direction.
erefore, a relatively oppy guidewire tip is used
to advance the coil into position. e guidewire
used to push the coil must be of the same diameter
as the coil itself (use a 0.035-inch guidewire for a
0.035-inch coil). e coil is pushed quickly along
the long distance of the catheter, but as it nears the
treatment site, it is best to slow down so that the
catheter does not whip around. e coil is radi-
opaque and can be visualized using uoroscopy.
e coil begins to twist as soon as it exits the cath-
eter and can be observed as it begins to twist. e
coil and the guidewire used to push it have about
the same radiographic consistency. is means
that it is not always easy to know when the coil has
been fully deployed from the catheter. Watch the
coil carefully so that it can be observed separat-
ing from the catheter. e key thing is not to let
the catheter tip withdraw or retract and allow the
following end of the coil to end up in an unwanted
position. During coil delivery, sometimes it is nec-
essary to administer forward pressure on the cath-
eter. In between placing coils, the catheter itself
may be advanced on its own and the blunt edge of
the catheter used to reposition or clump the coils
together.
When a very remote target requires emboliza-
tion or the vessels along the pathway to the tar-
get are small in caliber, even more telescoping is
required. Embolization of a type II endoleak in an
aortic aneurysm sac through the collaterals of the
superior mesenteric artery is an example of this
type of situation. A 6-Fr sheath is placed well into
the superior mesenteric artery. A long 5-Fr angio-
graphic catheter is used to select the best superior
mesenteric artery branch to use as a pathway and
the catheter is placed as far into that branch as pos-
sible. A microcatheter, usually 2.5-Fr and 150 cm
in length, is advanced through the 5-Fr catheter
and advanced to the target. e coils are placed
through the microcatheter. Because of the small
diameter of the microcatheter, it is not easily aspi-
rated of blood and the system is usually quite cir-
cuitous. It also may be challenging to push the coil
with a guidewire all the way through the micro-
catheter. If this is the case, a 1 cc or 3 cc syringe
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422 Coiling of peripheral aneurysms
lled with saline may be used to ush the coil out
of the microcatheter by injecting into the micro-
catheter forcefully. e coil will shoot out the other
end. is is a very fast way of delivering the coil but
is somewhat less accurate and care should be taken
to position the catheter carefully prior to injecting
with saline.
It is quite common in the fully heparinized
state for the patient to still have some ow of
blood through the area that has been coiled. is
makes it extra challenging to decide if additional
coils are required. In general, it is best to make a
plug of coils but it is preferable to try to be pre-
cise in the placement so that additional areas are
not occluded. In addition, at some point in creat-
ing a plug, there will be insucient room to place
additional coils and the trailing end of the most
recently placed coil may drag into another blood
vessel. is should be carefully monitored to avoid
it happening.
Coiling the internal iliac artery
A very common maneuver that is used as an
adjunct to stent–gra treatment of aortic aneu-
rysms is coiling of the internal iliac artery. is
may be required to treat an internal iliac artery
aneurysm. It may also be required so that a rela-
tively normal internal iliac artery can be coiled to
prevent backbleeding aer it is covered by a stent–
gra limb (Figure 29.2).
When coiling an internal iliac artery as an
adjunct to stent–gra exclusion of an aortic aneu-
rysm, it may be performed prior to aneurysm
treatment or at the same time. A 6-Fr sheath may
be placed from either the contralateral or ipsilat-
eral femoral access, depending on the angulation
revealed by aortography. Patients with nonaneu-
rysmal disease usually have an angle of origin of
the internal iliac artery that is acute and is not
simple to cannulate when coming from the ipsilat-
eral femoral artery. Internal iliac artery cannula-
tion is simpler in this case from the contralateral
side, coming over the aortic bifurcation. e tor-
tuosity of the aortoiliac segment in patients with
aneurysmal disease may completely change these
relationships and make ipsilateral access a reason-
able choice. In addition, there may be occasions
when it is not desirable to pass the sheath through
a particularly friable or diseased segment of the
contralateral iliac artery.
e tip of the sheath is placed in the origin of
the internal iliac artery if that is all that requires
coiling. A 5-Fr catheter is advanced over a guide-
wire and into the artery. e area of the neck
of the internal iliac artery is investigated, oen
with several dierent views. e usual goal is to
place a plug of coils in the origin of the artery
without occluding more branches than neces-
sary. Sometimes, the plug will migrate a little
further into the artery as the coils are being
placed. Aer the best view is identied, the posi-
tion of the image intensier is maintained. e
coil is selected, placed into the catheter with the
sti back end of a Bentson guidewire, and then
advanced the rest of the way to the target area by
Fig. 29.2 Coiling of an internal iliac artery aneu-
rysm. A telescoping system is constructed. A 6-Fr
sheath is placed in the internal iliac artery. A 5-Fr
catheter is then inserted through the sheath and
this is used to direct placement of the coils. The
coils are placed through the 5-Fr catheter.
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Vessel occluders 423
advancing the so end of the guidewire. Before
the coil comes out, the tip of the catheter is read-
justed, usually by withdrawing it slightly. e
coil is deployed. Aer several coils have been
deployed, the coil mass is shaped using the head
of the catheter to tamp them into a plug. Aer coil
placement is complete, a completion arteriogram
is obtained and the sheath removed.
With an internal iliac artery aneurysm, the
outlet branches to the artery must be occluded as
well as the artery itself. Finding all the branches
leading out of the aneurysm can be a challenge. It
helps to place the tip of the sheath all the way into
the aneurysm and then to use an angiographic
catheter to select out the branches and coil them
one at a time. e aneurysm itself is also lled
with coils. If the aneurysmal dilation is more
than 2 centimeters in diameter, it can be lled
with several coils or with a few longer pieces of
guidewire. is can be done by taking a remov-
able core guidewire, taking out the core, cutting it
into longer pieces that may be several centimeters
in length, and placing these as one would place a
coil. en the sheath is withdrawn so that its tip is
in the internal iliac artery proximal to the aneu-
rysmal dilation and coils are placed to occlude the
in ow.
VESSEL OCCLUDERS
Vessel occluders are nitinol-based cage-like
structures or self-expanding gras with one
end closed. ese devices open spontaneously
on being released. e cage-like structure func-
tions by means of a tight nitinol weave, which
generates thrombus formation and prevents
continued ow through the vessel in which it is
placed. One of the most common types of ves-
sel occluders is the Amplatz
™
closure device
(Figures 29.3, 29.4). A similar device is used
for minimally invasive closure of a patent fora-
men ovale. e closure device may have one lobe
or three lobes. is aects its stability, its con-
guration when deployed, and also its ability to
obstruct ow. e lobes of material are joined
together along the same stock. An appropriately
sized delivery sheath is placed so that the tip is at
the location where the vessel occluder is intended.
e guidewire is removed. At this point the sheath
can only be withdrawn and cannot be advanced.
e occluder is placed within the sheath. When it
is in the correct location, the sheath is withdrawn
to release the occluder. A torque device is placed
on the delivery wire. e torque and the wire are
rotated counterclockwise to release the device.
A
C
B
Fig. 29.3 Vessel occluder. (A) The vessel occluder is constrained within a small diameter feeding
tool that can be inserted into the hub of the sheath. The occluder is advanced in the constrained
shape into the sheath and is moved along the sheath by advancing the wire on which it is mounted.
(B)Thesheath has been withdrawn to expose the occluder and it has taken its trilobed shape.
Atorque device is affixed to the supporting delivery wire and the wire turned counterclockwise.
(C)The occluder is released into the vessel.
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