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374 Salvage of previous reconstructions
mind that thrombolysis may be required. Failing
endovascular sites are more likely to acquire fresh
thrombus or other material that could form an
embolus. Consider administering adequate hepa-
rin and avoid crossing lesions that appear likely
to embolize.
If the previous reconstruction was a stent, the
key maneuver in repeat treatment is to be cer-
tain that the guidewire is placed across the stent,
within the lumen, and not under the struts of the
stent. Guidewires in general, and Glidewires
®
in particular, may pass through the struts of a
stent and potentially lead to a stent-deforming
balloon angioplasty. If the operator cannot be
certain that the guidewire position is intralu-
minal, a catheter may be passed over the wire.
If the catheter is intraluminal, the catheter does
not catch on the side wall of the stent. The best
way to pass the wire through a stent is with a
loop on the leading end of the wire. Because
this may not be possible in the setting of in-
stent restenosis, it is best to magnify the field,
support the wire with a catheter, and pass the
wire very deliberately through the restenosis.
If the end of a previously placed stent is at the
origin of a branch artery, such as the common
iliac, renal, or subclavian artery, additional care
should be taken when crossing the stent. There
may be an exposed metal edge, which is not
opposed to the arterial wall, but is in the f low
lumen. This situation is one where passing a
wire through the stent struts is even more com-
mon. A soft-tipped guiding catheter or sheath
may be used to encounter the end of the stent.
Repeat balloon angioplasty within a previously
placed stent may cause balloon rupture, espe-
cially if it is a stainless steel, balloon-expandable
stent with sharp metal edges. The balloon may
occasionally catch on the stent, which prevents
it from being withdrawn. If the balloon seems to
get caught by the stent, consider advancing the
supporting guide catheter or sheath over the bal-
loon shaft closer to the stent to support the stent
in its position as the balloon is being removed.
If additional stents need to be placed, consider
overlapping slightly with the previously placed
stent. Assessment of recurrent stenosis within a
stent is sometimes difficult to assess with angi-
ography alone. IVUS typically offers more accu-
racy in the severity of the disease and the quality
of repair. IVUS is also helpful in attempting to
optimize the size of the stent lumen with the
reconstruction.
MANAGING OCCLUDED STENTS
Recanalizing an occluded stent can be challeng-
ing and has a higher risk of complications. e
long-term patency of recanalized occluded stents
is generally poor. Reintervention prior to occlusion
using the techniques described is more likely to
be successful and less risky. It also is important to
note that the risk of embolization during recanali-
zation of an occluded stent is higher than for most
other endovascular procedures.
e method of reconstr uction is usually planned
prior to the procedure, as the operator should con-
sider whether to use a distal lter, whether debulk-
ing is desirable, and how the lumen will be treated
(drug-coated balloon versus reline with covered
stent versus other method). e initial step is to
set up a platform that can be used to cross the
stent. Aspecic set of maneuvers are used to cross
the stent, and having a method of reconstruction
planned is also helpful, as it may take time to set
up various tools. It is appropriate to place a sheath
close to the origin of the occluded stent. In some
settings, there may be signicant disease in the
inow vessels approaching the occluded stent,
which would preclude full sheath advancement.
e operator must decide whether to cross the
entire lesion, including the diseased stent, prior to
treatment. is is usually the best strategy. If this is
not possible, the other option is to treat the diseased
inow rst, and then advance the sheath through
this area to get the tip closer to the occluded stent.
e sheath should be of a size adequate to serve as
a platform for whatever reconstructive tools are
being considered. Tools for reconstruction include
plain balloon angioplasty, drug-coated balloon
angioplasty, drug-eluting stent, covered stent, and
debulking with atherectomy.
After the sheath is in place, a 0.014- or 0.018-
inch diameter guidewire is modified with the
definitive angled bend in the wire about 3–5mm
from the leading end of the wire. The guidewire
is advanced into the occluded stent with the
help of a chronic total occlusion (CTO) cathe-
ter. It is unpredictable as to whether the mate-
rial within the stent will be hard, soft, or mixed.
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Infrainguinal bypass graft 375
It is common for it to be mixed, even when the
occlusion is quite old from a clinical stand-
point. Usually, what is encountered is that the
wire moves well through most of the length of
the stent, suggesting that this is softer material,
but that there are typically one or several areas
along the length of the stent where the guidewire
encounters significant resistance. In this situa-
tion, it helps to have the support of the sheath,
with its tip close to the beginning of the occlu-
sion. Be patient, continue to drill, and advance
the CTO catheter closer to the tip for more lever-
age when a recalcitrant portion of the occlusion
is encountered. The wire is used to drill through
the occlusion. If the wire stalls and options have
been exhausted, the wire can be withdrawn a few
centimeters and then readvanced in an effort to
find an alternative pathway. The CTO catheter
is intermittently advanced to support the guide-
wire. As the wire makes progress through the
lumen of the occluded stent, it may take a mean-
dering course. The reconstituted segment dis-
tal to the stent occlusion can be evaluated with
proximal arteriography that feeds the distal run
up through collaterals. If the wire cannot pass
using these maneuvers, it can also be advanced
to form a knuckle or loop at the tip of the wire.
This can be advanced in the same manner as
might be used for a subintimal recanalization.
One of the risks is that the guidewire will bur-
row behind the stent and go into the wrong plane
between the stent and the arterial wall. If there
is any doubt about this, it can be resolved with
IVUS. However, oblique views of the stent on u-
oroscopy will usually show if the wire has passed
outside the stent. Using the drilling wire sup-
ported by a catheter, it is quite common for the
wire to drill through the stent occlusion and into
the true lumen of the artery distal to the stent.
Aer crossing the stent, a distal protection lter
should be considered. e risk of embolization
during reconstruction is higher than usual, as
mentioned above. Distal protection lters are dis-
cussed in Chapter 20. With the lter in place, the
operator can go on to perform a reconstruction.
One disadvantage of using a distal lter is that the
wire used for reconstruction is determined by the
wire required for the use of the lter. e support
provided by the wire may be poor, since it is a low-
prole 0.014-inch wire.
It is helpful to review previous angiograms or
duplex scans that might give a hint as to why the
stent occluded. Sometimes, there is residual ste-
nosis or restenosis identied that must be man-
aged. e key maneuver is to gain enough lumen
so that when ow is restored the reconstruction
will be adequate. is can be achieved by debulk-
ing or by very aggressive balloon expansion of the
lumen. is process can cause material to come
loose and to embolize, and this is why a distal l-
ter is helpful in this setting. e two approaches
with the best data for reconstruction here include
either drug-coated balloon angioplasty or relining
the occluded stent with a covered stent such as a
Viabahn™ stent.
INFRAINGUINAL BYPASS GRAFT
Failing infrainguinal bypass grafts present a
common application of endovascular interven-
tion for salvage. One of the most difficult facets
of bypass graft angioplasty is locating and enter-
ing the graft from its proximal end, especially if
the stenosis is severe and at the proximal anas-
tomosis. (See Chapter 9 for a detailed discussion
of the technique for entering an infrainguinal
graft.) It is useful to review pretreatment duplex
scans and any available completion angiograms
from the previous bypass procedure. If the graft
is placed subcutaneously, such as an in-situ
graft, a percutaneous puncture of the graft in
the subcutaneous position can be performed
using micropuncture technique with ultrasound
guidance. If this is chosen as the access method,
a 4-Fr sheath and 0.014-inch guidewire system
should be used. Most grafts are entered through
the proximal anastomosis using a directional
catheter and a 0.014-inch wire.
e method for approaching an infraingui-
nal bypass gra is dependent on the location of
its proximal anastomosis. Gras that originate
from the anterior wall of the common femo-
ral artery are accessed through a contralateral
femoral artery puncture and passage of the
guidewire and catheter over the aortic bifurca-
tion (Figure 26.1). Gras originating from the
supercial femoral artery, popliteal artery, or
deep femoral artery can be cannulated aer an
antegrade ipsilateral femoral artery puncture or
an up-and-over approach (Figure 26.2).
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376 Salvage of previous reconstructions
If the stenosis is preocclusive, it may be dicult
to identify the proximal origin of the gra because
of very low ow. Since most anastomoses are placed
on the anterior side of the artery of origin, steep
oblique views or near lateral views may be helpful
in localizing the area of interest. A stump or hood
of gra is sometimes visible when local contrast is
injected. is area should be probed with a steer-
able guidewire. Sometimes, multiple oblique views
are required.
Arteriography and confirmation of guide-
wire placement is performed through the side
arm of the hemostatic sheath, which has been
placed to provide an antegrade approach to the
A
B
C D E
Fig. 26.1 Balloon angioplasty of an infrainguinal bypass graft through an up-and-over approach.
(A)An infrainguinal bypass graft that originates from the common femoral artery has developed a
proximal graft lesion. (B) An up-and-over sheath is placed and arteriography performed. (C) The
guidewire is passed through the graft lesion. (D) Balloon angioplasty is performed. (E) Completion
arteriography is performed through the sheath.
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Infrainguinal bypass graft 377
infrainguinal bypass. Heparin is administered
(75–100 U/kg) prior to passage of the balloon
catheter, since the catheter itself may stop flow
in the graft and may risk occlusion of the bypass.
If the stenosis is preocclusive, simple wire pas-
sage may impede flow even further and create
a standing column of blood in the graft, with
a commensurate increase in thrombosis risk.
In this setting, early and aggressive anticoagu-
lation might be helpful. Consider placing the
guidewire through the length of the bypass graft
before beginning balloon angioplasty, just in
case low flow in the graft progresses to throm-
bosis of the graft. After the graft is entered, the
balloon angioplasty catheter is passed over the
guidewire.
A B C D
E F
Fig. 26.2 Balloon angioplasty of an infrainguinal bypass graft through an antegrade ipsilateral
approach. (A) This approach is useful for interventions in infrainguinal bypass grafts that originate
from the superficial femoral, popliteal, or profunda femoris arteries. (B) An antegrade femoral sheath
is placed and arteriography performed. (C) The guidewire is directed into the vein graft using a
selective catheter and passed across the vein graft lesion. (D) The selective catheter is removed.
(E)Balloon angioplasty of the infrainguinal bypass graft is performed. (F) Completion arteriography
isperformed while maintaining guidewire access.
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378 Salvage of previous reconstructions
High pressures (up to 20 atm) may be
required to reopen a segment of intimal hyper-
plastic disease. Stenoses within the graft or at an
anastomosis generally require higher pressures
and longer inflation times. The likelihood of
a localized dissection is low but the graft may
rupture if it is overdilated. After angioplasty, the
balloon is removed while the guidewire is main-
tained and completion arteriography performed
through the sheath.
EXTRA-ANATOMIC BYPASSES:
AXILLOFEMORAL AND
FEMORAL–FEMORAL
Extra-anatomic bypass grafts, such as an axillo-
femoral graft or a femoral–femoral bypass graft,
may be evaluated arteriographically by direct
puncture and catheter placement or through
entry into the native vasculature proximal or
distal to the graft and cannulation with a cathe-
ter. Selective catheterization of prosthetic grafts
is detailed in Chapter 9. When an axillofemoral
bypass graft is punctured and accessed, it is best
to direct the access either proximally or distally
toward the suspected lesion (either inflow or
outflow). The graft can be punctured where it is
palpable along the anterior axillary line but infe-
rior to the pectoralis major muscle. Interventions
to salvage axillofemoral bypass grafts usually
involve distal lesions, either at the femoral anas-
tomosis or in the runoff. Occasionally, a new
subclavian or axillary artery lesion will develop
that threatens graft patency. After arteriography,
an access sheath is placed. Dilators must be used
to permit the entry of the sheath, and the small-
est caliber sheath that is adequate for the inter-
vention should be placed. A balloon catheter is
passed over the guidewire and angioplasty per-
formed. After the intervention, pressure is held
at the site of the puncture so that the graft itself
maintains flow and a platelet plug is permitted
to form. There is no closure device approved for
percutaneous access to a prosthetic bypass graft.
A femoral–femoral graft can also be accessed
along its length, wherever it is most superficially
located. This can be evaluated by ultrasound.
Consideration should be given to making sure
that there is working room between the location
of the access and the lesion.
RECONSTRUCTIONS FOR
AORTOILIAC DISEASE:
AORTOFEMORAL, ILIOFEMORAL,
AND AORTOILIAC BYPASSES
Most failing in-line gras that were originally
performed for aortoiliac occlusive disease should
be treated with repeat surgery. e most common
lesions aecting these gras are at the distal anas-
tomosis. Nevertheless, endovascular intervention
is well suited to treat lesions that are at the proxi-
mal anastomosis and would be dicult to reach
surgically. Figure 26.3 demonstrates an aortic
gra that is failing due to progression of aortic
disease. Balloon angioplasty and stent placement
in the infrarenal aorta are used to prevent repeat
open aortic surgery.
Inflow disease may also occur proximal to an
iliofemoral bypass graft. This may be reached
through an ipsilateral or contralateral femoral
puncture, depending on the site of the proxi-
mal anastomosis. Grafts that end in the iliac
arteries may be difficult to cannulate through
an ipsilateral femoral puncture (Figure 26.4).
The guidewire naturally tends to remain within
the native circulation. An oblique view and steer-
able guidewire and angle tip selective catheter are
used to locate and enter the graft. Aortofemoral
bypass graft bifurcations are manufactured at a
fairly narrow angle, and crossing over the graft
bifurcation may be a challenge. It is usually
simpler to cross with an angiographic catheter
than with an access sheath, since the catheter is
more flexible. A selective catheter with a tight
hook, such as an RIM catheter, may be used with
a steerable 0.014-inch guidewire. However, if a
graft limb must be treated and cannot be reached
by an ipsilateral puncture, it is usually best to
approach from a proximal puncture in the upper
extremity to benefit from the relatively straight
pathway to the groin.
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Reconstructions for aortoiliac disease: Aortofemoral, iliofemoral, and aortoiliac bypasses 379
A B C
D E
Fig. 26.3 Endovascular salvage of an aortofemoral bypass graft. (A) Disease has progressed in the
residual infrarenal aorta after prior aortofemoral graft placement. (B) A femoral sheath and guidewire
are placed. (C) Stent placement is performed distal to the renal arteries. (D) Poststent balloon angio-
plasty expands the stent to its correct profile. (E) Completion arteriography is performed through a
proximally placed flush catheter.
https://t.me/med1917
380 Salvage of previous reconstructions
A
B C D
Fig. 26.4 Retrograde guidewire placement after iliac anastomosis. (A) The iliac artery is the recipient
artery of a previously placed bypass graft and the common iliac artery has been ligated. (B) The ten-
dency of a guidewire placed retrograde is to remain in the native circulation. (C) A selective catheter
is placed and used to direct the guidewire. (D) The wire is passed across the anastomosis.
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381
27
Hybrid procedures
PRINCIPLES OF HYBRID
PROCEDURES
Hybrid procedures comprise both open and endo-
vascular components and may be required when
there is extensive or multilevel occlusive disease,
extensive or multilevel aneurysmal disease, or a
combination of open and aneurysmal disease. e
goal of a hybrid procedure is to tailor the opera-
tion to the patient’s needs and allow all levels to be
reconstructed in a single setting rather than per-
forming dierent procedures in a staged setting.
Another way to th ink about it is to consider a hybrid
procedure when a reconstruction is planned and
any inow or outow must be improved. Hybrid
procedures also allow control of the access site
and they permit the operation to be customized to
the specic patient’s needs. In some hybrid proce-
dures, there is no alternative staged approach and
the open component provides access for the endo-
vascular component, which may not otherwise be
easily available. An example of this is the combina-
tion of a femoral endarterectomy, which is open,
and using that as an access for a femoral–popliteal
or tibial endovascular reconstruction.
In cases of extensive aneurysmal disease, if the
endovascular technology is not adaptable to the
complex morphology, then a hybrid procedure
may be considered. An example of this is when
debranching procedures of the carotid and sub-
clavian arteries are performed in combination
with an arch or thoracic aortic stent–gra. e
debranching procedures include a le carotid-to-
subclavian bypass, a carotid-to-carotid bypass, an
ascending aorta-to-innominate artery bypass, or
some combination of these.
Procedures in which open access is required
form another category of hybrid cases. In this
case, the access sheath may be too large for
the artery to be inserted percutaneously. Open
exposure for sheath insertion is performed fol-
lowed by artery repair afterward. Occasionally,
in an emergency procedure, it makes more sense
to place the sheath percutaneously so that it
may be done rapidly, and then perform the open
exposure and repair the vessel after the recon-
struction. Some examples of hybrid procedures
are demonstrated in Figu r e 27.1. Examples of
hybrid procedures include, but are not limited
to: femoral endarterectomy plus proximal or dis-
tal endovascular intervention; inf low bypass at
the iliac level with outflow endovascular inter-
vention at the femoral–popliteal or tibial level;
inflow aortoiliac stent and infrainguinal bypass;
inflow bypass at the femoral–popliteal level and
outflow tibial intervention; and superficial fem-
oral artery (SFA) stent and popliteal-to-distal
bypass. Endovascular intervention can be com-
bined with any type of bypass including axil-
lofemoral bypass and femoral–femoral bypass.
Endovascular intervention can also be used to
create improved arterial inflow or venous out-
flow for dialysis procedures.
TECHNICAL POINTS FOR
PERFORMING HYBRID
PROCEDURES
Whenever a hybrid procedure is to be performed,
be sure to prep the patient such that alternative
access sites are available in case the planned pro-
cedure is not possible. e contralateral femoral
area or the upper extremity might be prepared for
backup access depending on the case plan. One of
these may be needed for inow control in some
circumstances.
https://t.me/med1917
382 Hybrid procedures
A
B
E
C
D
Fig. 27.1 Examples of hybrid procedures. (A) The patient presents with an iliac artery stenosis requir-
ing angioplasty and a stent and a common femoral artery lesion requiring endarterectomy. The
left iliac stent is placed followed by a left common femoral endarterectomy and patch angioplasty.
(B)Thepatient presents with a left common femoral artery lesion and an SFA occlusion. The left femoral
endarterectomy is performed as well as an SFA stent placement. (C) This patient requires limb salvage
by treating both the SFA and tibial levels. SFA occlusion and multivessel tibial disease is treated by
crossing the left SFA occlusion and placing a stent, followed by a popliteal-to-distal vein bypass graft.
(D)The patient requires a femoral-to-popliteal bypass graft for a long segment SFA and popliteal artery
occlusion. The patient also has extensive multivessel tibial occlusive disease. In this case, the anterior
tibial artery stenosis is treated with angioplasty as a portion of the hybrid procedure. Performing tibial
angioplasty improves perfusion to the lower leg and also improves runoff for the femoral-to-popliteal
bypass. (E) Another type of hybrid procedure, which is described in more detail in Chapter 28, may be
performed when disease affects the aorta and its very proximal branches. In this case the patient pres-
ents with a type B aortic dissection that extends from the origin of the left subclavian artery. The patient
is treated with a left carotid-to-subclavian bypass and a stent–graft placed in the thoracic aorta.
https://t.me/med1917
Technical points for performing hybrid procedures 383
One of the key features of hybrid procedures is
that there is typically the requirement for “work-
ing room” or usable length of artery between the
open procedure and the endovascular procedure
(Figu r e 2 7. 2). e open procedure requires arte-
rial clamp placement in order to perform the
anastomosis or the endarterectomy, so there must
be at least 1 cm or more of clearance between the
lesion and the clamp site. e working room must
provide a safe place to clamp the artery and not
interfere with either of the two reconstructions.
If the end of the stent is nearby, for example, it is
best to avoid clamping on it or near it. Likewise,
if a clamp is too close to an endarterectomy site,
it may compromise the plaque removal or make
the procedure less safe. If a clamp site is too close
to an anastomosis site, it could lead to techni-
cal defects in the anastomosis. If the available
length of artery is too short or is not acceptable
for clamping, there is an alternative. Treatment of
the inow iliac lesion can be performed through
an alternative percutaneous access, such as the
contralateral common femoral artery, using an
up-and-over approach. e balloon can then
be reinated within the inow stent in order to
achieve inow control.
In general, it is best to perform the inow proce-
dure rst. If the time of the procedure is extended
due to the extensive levels of disease being treated,
adequate anticoagulation must be administered to
avoid thrombus formation.
If an endarterectomy is included in the pro-
cedure, it is usually best to avoid crossing the
endarterectomy point with a guidewire aer the
endarterectomy is completed (Fi g ure 27. 3). In this
setting, the guidewire can easily become trapped
under the edge of the plaque where it has been
divided and enter the subintimal plane. If the
reconstruction includes a vein gra, it is usually
best to avoid any aggressive maneuvers or sheath
insertion into the vein gra because it can be easily
injured or torn. Too much tension on the anasto-
mosis will cause bleeding and can cause avulsion
of the vein, even if the anastomosis was hemostatic
initially.
Hemostasis from the access artery that has
been fully exposed usually requires more secu-
rity than when hemostasis is achieved around a
percutaneous sheath. e natural tendency is for
bleeding to occur around the sheath, and when
there is no other tissue around the artery, as occurs
when open exposure has been achieved, hemosta-
sis is more challenging. A loop of dacron tape or
a vessel loop is required around the artery. is is
needed for control of the artery in case it requires
urgent clamp placement and also for hemostasis
while the sheath is in place. If hemostasis is not
adequate, two loops with a Ramel tourniquet may
be required. When the sheath is placed through
an open exposure of the artery, there is less tissue
in place to hold the sheath. erefore, the sheath
tends to slide outward and retract from the artery,
and this requires a little extra attention. If the
artery has substantial tortuosity, the artery may
attempt to assume its usual conguration and this
results in the sheath being continuously pressured
to push back out of the artery, since the sheath and
wire are a straightening force. Consider stitching
the sheath in place to secure it.
A B
Fig. 27.2 Working room. (A) The patient presents
with a long external iliac artery stenosis. The
common femoral artery is occluded. (B) In this
magnified view, the working room refers to the
available length of artery between the distal end
of the endovascular reconstruction and the proxi-
mal end of the open reconstruction. The safety
of the procedure depends on this segment, since
it must be clamped in order to perform the open
procedure. Another option to consider if the
working room is not adequate is to perform the
endovascular procedure through an up-and-over
approach from the contralateral side and then
use this approach for an inflow occlusion balloon
to provide hemostasis.
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