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354 Complex lower extremity revascularization

Important lesion-related factors in determin-

ing long-term success include lesion length and

whether the lesion presented as an occlusion.

With respect to recanalizing occlusions, other

important factors in achieving success include

whether thelesion crossed a joint space and also

whether the entry and exit segments into the sub-

intimal space were well treated at the time of the

reconstruction. ere are multiple adjunctive tools

for getting across lesions and also multiple tools

forreconstructing arteries.

For the femoral and popliteal arteries, there are

several dierent methods of reconstruction aer

crossing a stenotic or occluded lesion (Figure 25.7).

Patients may be selected on the basis of presenta-

tion and lesion type, and physician experience and

preference also play an important role when there

are several choices. e method of reconstruction

with the longest track record is standard balloon

angioplasty. is is still a reasonable option in very

focal lesions and has a decent long-term outlook.

e problem with standard balloon angioplasty

is that the patencies are only very satisfactory

for focal lesions. Lesions that develop dissection

aer angioplasty should be managed with dissec-

tion repair. Drug-coated balloons, accompanied

by focal dissection repair, also appear to oer

improved patency for femoral–popliteal lesions;

as lesion length and complexity increase, the less

likely is plain angioplasty the best solution for the

patient’s problem. e longer and more complex

the lesion becomes, the less satisfactory the long-

term patency. Another option is balloon angio-

plasty with selective stenting. is is an option that

has been practiced widely and remains a common

approach. In this situation, balloon angioplasty

alone is performed for an SFA or popliteal artery

lesion and if aer balloon angioplasty there is

evidence of signicant dissection, stent placement

is performed. Stent placement has improved sig-

nicantly over the past several years, as there are

multiple choices of dierent kinds of stents, multi-

ple dierent types of designs, and many options for

stent placement. Because stents are relatively low

in prole, none require more than a 6-Fr sheath.

ey do not add much morbidity or time and the

added risk of stent replacement is quite low, at least

during the immediate time frame or rst 30 days.

e longer-term issue around stent placement has

to do with the fact that recurrent in-stent stenosis

occurs oen and has no treatment. When recurrent

stenosis develops, it oen involves the whole length

of the stent. Stents also develop fractures, which

are related to external compressive forces. Because

of the combined issues around recurrent stenosis

and stent fracture, there is enthusiasm for the idea

that stent placement should be as limited as pos-

sible. Another option is to proceed with primary

stenting. ere is some evidence that at 1 year, pri-

mary stenting produces better results than balloon

angioplasty and selective stenting. In addition to

having no treatment for recurrent stenosis and

B C

E F

Fig. 25.7 Multiple methods of reconstruction

are available for superﬁcial femoral and popliteal

artery lesions. (A) Plain old balloon angioplasty

(POBA). (B) Cryoplasty. (C) Self-expanding

stents. (D) Atherectomy. (E) Laser atherectomy.

(F)Stent–graft.

https://t.me/med1917

Femoral–popliteal occlusive disease 355

stent fractures, stents that are placed at specic

locations may cause other problems. Between the

adductor canal and the origin of the tibial vessels,

the popliteal arter y must be exible with bending at

the knee. Stents in this location should be avoided

if possible. Because of these issues, the idea has

developed in recent years that as little scaolding

as possible should be le behind aer treatment.

In this setting, focal dissection repair can be used

to manage the acute negative eects of angioplasty

and ensure lumen gain, and drug-coated balloons

can be used to deliver medication that will improve

long-term results by reducing recurrent stenosis.

Other options include cryoplasty, atherectomy,

stent–gras, and cutting balloon angioplasty.

ese are described in Chapter 20. e advantage

of stent–gra placement is that there is no potential

for tissue ingrowth, since there are no open spaces

in the stent. ese tend to fail at the ends (“candy

wrapper lesion”) or thrombose if adequate lumen

cannot be created along its length, due to external

impingement from bulky plaque. Atherectomy is

particularly useful for heavily calcied lesions,

especially if the disease is diuse or eccentric.

Atherectomy may nd a new role now that drug-

coated balloon angioplasty is readily available to

ameliorate the negative or inammatory eects of

shaving the plaque.

Some of the new devices and techniques are

based on the 0.014- or 0.018-inch platform. One of

the best ways to gain experience with low-prole

systems is to use them routinely for infrainguinal

interventions. Experience may be gained with a

variety of dierent types of wires from the soest,

oppiest, and least traumatic to hydrophilic coated

to stier wires, which can be used as exchange

guidewires. ere are numerous balloon catheters,

both monorail and coax ial, that are compatible with

low-prole systems. ere are also numerous stents

available on low-prole systems. When the desired

stent is only available on a 0.035-inch system, it

can still be placed over a 0.014-inch or 0.018-inch

guidewire. e 0.014-inch and 0.018-inch guide-

wires have the added advantage of being com-

patible with multiple other devices including

aspiration catheters, atherectomy devices, and re-

entry devices.

When initiating a case, a standard Glidewire

™

and diagnostic catheter can be used to pass over

the aortic bifurcation and then, once the aortic

bifurcation has been crossed, place a sti exchange

guidewire through the catheter and then remove

the catheter. A series of dilators are used at the

femoral access site and then the access sheath

is placed over the exchange wire. e tip of the

exchange wire is placed into the largest branch

or collateral near to the lesion in order to get the

tip of the sheath as close to the lesion as possible.

Adecision must be made in infrainguinal work as

to whether the tip of the sheath will enter the SFA

or whether it will be placed in the common femoral

artery in order to treat an SFA lesion. is deci-

sion is made based on the location of the lesion.

If a popliteal or even tibial artery lesion is being

treated and the SFA is relatively free of occlusive

disease, the sheath is advanced well into the SFA. If

the SFA has signicant disease, this inow disease

must be treated prior to crossing with a sheath. If

the SFA is small and tortuous, the sheath may stop

ow and care must be taken when making a deci-

sion on whether the sheath should be advanced

through it. In general, the more challenging it is to

advance the sheath, the more challenging it will be

to remove it.

Subsequently, the sti exchange wire and the

dilator for the sheath are removed and the 0.014-

inch or 0.018-inch diameter guidewire is placed.

Acurve is created at the tip of the wire if dealing

with a stenosis. An acute bend (as discussed previ-

ously) is created if the lesion is an occlusion. e

wire is advanced into the sheath. Aer the wire

reaches the tip of the sheath, contrast is admin-

istered though the side arm of the sheath and the

lesion and the area that must be crossed is road

mapped. e wire has a steerable tip. A torque

device is placed on the guidewire and the lesion is

crossed using the road map and the steerable wire.

e choice of subintimal versus translumi-

nal recanalization of the supercial femoral and

popliteal arteries has been discussed previously.

e operator has to choose which method to use

(Figure 25.8). ese are dierent techniques

and the advantages of each are described in

Chapter16 (“Crossing occlusions”, Table 16.1, and

Figures16.2 and 16. 3). In general, it makes sense

to attempt transluminal crossing initially. If this

is not possible, subintimal crossing is a reasonable

default position.

Aer traversal of the lesion has been com-

pleted, a catheter is usually advanced over the wire

and contrast administered to prove that the wire

is in the true lumen. is is especially important

https://t.me/med1917

356 Complex lower extremity revascularization

aer crossing a dicult lesion. e desired repair

devices or reconstruction devices are used next.

is might include vessel preparation with modi-

ed balloons, atherectomy, or plain balloons fol-

lowed by denitive therapy with drug-coated

balloons, self-expanding nitinol stents, woven

nitinol stents, stent–gras, drug-eluting stents,

or other devices. During this process, manipula-

tion and handling of the low-prole guidewire is

performed on a regular basis. Experience in keep-

ing the tip of the wire stable and also in passing

these low-prole devices can be obtained by focus-

ing on this attentively during revascularization

procedures. e operator learns how to get the tip

of the sheath close to the target lesion and how to

save contrast and manipulate the imaging so that

the most direct information can be obtained. e

likelihood that a low-prole guidewire or the low-

prole catheters would occlude ow is low, and this

also helps with visualization.

Subintimal angioplasty

Subintimal angioplasty is a generalized description

of use of the subintimal plane in order to pass the

guidewire beyond the lesion. ere is a potential

space outside the lesion and within the adventitia

that is usually smooth. e general nomenclature

of subintimal angioplasty includes all types of

reconstruction that are placed in the subintimal

space. ere are dierences between transluminal

and subintimal passage. For example, with translu-

minal passage of the guidewire, the operator leads

with the tip. In the subintimal space, the operator

leads with the loop of the guidewire, which dis-

sects along the plane just outside the plaque. In

complex lesions, especially if short occlusions are

present, sometimes the operator does not know if

the guidewire is subintimal or transluminal. e

endovascular treatment of long occlusions (i.e.,

more than a few centimeters) depends on pas-

sage in the subintimal plane. is technique, more

than any other single maneuver, has signicantly

decreased the need for femoral–popliteal bypass.

Use of the subintimal space for reconstruction is all

about passing the guidewire out of the true lumen

and into the subintimal segment, then along the

subintimal passageway, and then re-entering into

the true lumen. ese specic steps are described

below.

Set yourself up for success by placing an ade-

quately sized sheath and placing its tip close to

the lesion. Obtain good runo pictures so you

know where the reconstitution site is located and

that it is not an isolated segment. You will also

know that by opening the lesion, it will have the

desired eect from a hemodynamic standpoint.

Anticoagulate the patient well, even before enter-

ing the occlusion, because thrombus formation is

enhanced in these low ow circuits. Subintimal

angioplasty is described in more detail in

Chapter20.

e key to entering the subintimal space

is locating the correct origin of the occlusion

A B C

Fig. 25.8 Subintimal versus transluminal recana-

lization of the superﬁcial femoral and popliteal

arteries. (A) An SFA occlusion is approached

with a telescoping platform. A 6-Fr sheath is

placed just proximal to the occlusion. A 4-Fr

catheter or a microcatheter is placed through

the sheath and the tip of the catheter is used to

direct and support a crossing guidewire, usually a

0.018-inch or 0.014-inch wire. (B) The low-proﬁle

wire has a bend at the tip of the wire. The wire

is rotated rapidly to drill into the lesion. As the

wire advances, the microcatheter and/or the

4-Fr catheter can be advanced intermittently to

support the wire. (C) If progress in the intralumi-

nal space stalls and the wire cannot be advanced

transluminally, the crossing procedure can be

converted to a subintimal approach. The wire can

be advanced more forcefully until the tip bends

and forms a loop. The loop typically advances

into the subintimal space.

https://t.me/med1917

Femoral–popliteal occlusive disease 357

(Figure 25.9). If there is a stump of open SFA,

an angle tip catheter is placed in the stump with

the end of the catheter pointed at the plaque/

artery wall interface. It is usually best to point the

catheter opposite to the side with the largest col-

lateral. Put the tip of the catheter right into the

plaque and push the Glidewire

forward. e tip

of the Glidewire

catches and a loop forms right

behind it, which travels along the subintimal plane.

Ifthere is no stump of proximal SFA, the location

of the artery can oen be identied by the presence

of calcication or engorged vasa vasorum lining

the wall of the occluded artery. Point the catheter

tip away from the profunda femoris artery and

toward the side of the SFA and push the guidewire

forward. A selective catheter with a relatively sti

tip and a hockey stick shape works best for this.

Aer the guidewire is in the subintimal space,

advance the catheter behind it (Figure 25.10).

Leave the loop of guidewire intact, but advance the

B C

D E

Fig. 25.9 Entering the subintimal space. (A) A sheath is placed in proximity to the occlusion. In this

case, since the occlusion begins in the proximal SFA, a sheath is placed over the aortic bifurcation,

using the profunda femoris artery to anchor an exchange guidewire during sheath insertion. (B) An

angle tip catheter is used to direct the guidewire tip away from the profunda femoris artery or any

large branches. Take advantage of any available stump that provides entry to the occlusion. (C) The

tip of the Glidewire

buckles and advances into the subintimal space. (D) The catheter is advanced

over the guidewire. (E) The loop is carefully maintained.

https://t.me/med1917

358 Complex lower extremity revascularization

catheter to support it and enhance the pushability.

e loop works best if it is not too wide. is tends

to occur if the guidewire gets too much ahead of the

catheter. e best part of the guidewire to lead the

loop is the segment right behind the more exible

couple of centimeters of tip. If the loop becomes

too wide, it tends to spiral around the artery more

and is also less successful at forcing its way into the

true lumen at the distal reconstitution site.

Re-entry into the true lumen is usually accom-

plished with the loop itself (Figure25.11). e tip

of the sheath proximally should be at a location

where contrast administration will illuminate the

distal reconstituting segment by ow through col-

laterals. e advancing loop is supported by the

catheter right behind the loop. e ability of the

loop to enter the true lumen depends on a dieren-

tial in wall stiness between the occluded segment

and the patent, reconstituted segment. At some

point, the path of least resistance for the loop is to

enter the true lumen rather than the more resistive

space of the subintimal space in a soer and patent

artery. Keeping the loop small in diameter seems to

facilitate this. When the loop breaks into the true

lumen, it changes in appearance as the wire enters

a free space. Aer this occurs, advance the cath-

eter into the true lumen and pull the guidewire out

to make sure there is backbleeding. If so, admin-

ister contrast in order to visualize the runo.

Occasionally, the catheter will be in a collateral. If

the distal re-entry site is heavily calcied, the loop

may bounce o of it and fail to re-enter. ere are

some tricks that can be used, but none of them

work very well. One is to remove the loop and push

the sti catheter tip up to the reconstituted seg-

ment and push with the guidewire, directed and

with maximum support. Another option is to place

an angioplasty balloon over the subintimal wire

and perform angioplasty to fracture the plaque and

create a space to re-enter. Yet another option is to

inate the angioplasty balloon, use this as support,

and push the guidewire through it.

e best option if the loop does not re-enter is

to go straight to a re-entry catheter (Figure 25.12).

ere are several reasons why. One is that you can

spend a lot of valuable time attempting maneuvers

with only a low likelihood of success. Another is

that the subintimal space at the level of the recon-

stituted segment may become beaten up and pat-

ulous with all these maneuvers. is makes the

re-entry catheters less eective. Re-entry catheters

rely on the ability to be passed into a tight subin-

timal space and to use that for leverage to support

needle passage into the true lumen. Re-entry cath-

eters are useful when no other maneuver will do

the job. A 6-Fr sheath is required. A 7-Fr sheath

A B C

E F

Fig. 25.10 Passing along the subintimal space.

(A) The guidewire loop must be well managed.

The best way to do this is to advance the

catheter incrementally to support the wire.

(B)The guidewire is advanced as long as the loop

itself passes easily and the loop remains nar-

row. (C) After several centimeters of guidewire

have passed out of the catheter, the catheter is

advanced. If the loop has hit an area of increased

resistance in the occlusion, the catheter may be

advanced up to the base of the loop. (D) The

guidewire may then be advanced again ahead of

the catheter. (E) If the guidewire is advanced too

far ahead of the catheter, it may begin to follow

a spiral or diagonal pattern. (F) Avoid permitting

the loop to get too big. It will follow less pre-

dictable patterns and will not be effective as a

re-entry tool.

https://t.me/med1917

Femoral–popliteal occlusive disease 359

may be advisable if the approach is up-and-over

the aortic bifurcation, the bifurcation is narrow,

or the iliac arteries are tortuous. e subintimal

space may be gently dilated over the length of the

occlusion with a 3- or 4-mm balloon if the device

will not advance along the subintimal space. Do

not dilate the distal most segment of the subinti-

mal space near the re-entry zone; this space is best

when it is tight. Support for the device is limited by

the fact that a 0.014-inch guidewire is used and also

that the device must be passed right to the end of

the wire. is does not provide much of a rail over

which to work. Pass the re-entry catheter along the

subintimal space so that the location from which

the needle protrudes (which is not at the very tip)

is opposite the segment desired for re-entry. Even

if the guidewire has slipped too far down the artery

on previous attempts, the catheter can be directed

toward the best place to re-enter. is oen means,

however, that the actual tip of the device will be

nestled in a tight spot more distal to the location

where the needle will be placed. e device is ori-

ented using either IVUS (Pioneer Plus catheter)

or an external marker under uoroscopic visual-

ization (Outback

catheter). e needle is placed

in the true lumen and the 0.014-inch guidewire

advanced. e needle is retracted. e guidewire is

carefully maintained in place as the re-entry cath-

eter is withdrawn. Be careful to use a long guide-

wire initially, usually 300 cm, to accommodate the

long re-entry catheter and also the distance inside

the patient.

Bidirectional approach

Chapter 16 describes how to cross crossing chal-

lenging lesions and includes a discussion about

when to approach a lesion from the opposite direc-

tion. is is a lso known as a bidirectional approach.

e strategy for this is described in Figure 16.6.

If an occlusion of the femoral–popliteal segment

cannot be crossed using an antegrade approach,

Fig. 25.11 Re-entry into the true lumen. (A) The patent distal segment is visualized by administering

contrast through the sheath and having it travel through profunda femoris artery collaterals. The loop

of Glidewire

and supporting catheter are advanced. (B) The loop of guidewire itself usually re-enters

the true lumen. (C) The loop is withdrawn and the guidewire rotated to show that it is free and not

trapped in the subintimal space. (D) Contrast is administered to conﬁrm the presence of the catheter

in the distal reconstituted true lumen.

https://t.me/med1917

360 Complex lower extremity revascularization

a bidirectional approach may be appropriate.

e technique used for a bidirectional approach

is demonstrated in Figure 25.13. A guidewire

passed from a distal access site typically penetrates

the distal cap of the occlusion with a higher rate

of success than with a wire passed from an ante-

grade direction that encounters the proximal cap.

e retrograde wire is advanced into the area of

the catheter that has been passed over the ante-

grade wire. e wires are oen in separate planes.

e tissue between these planes can be disrupted

using balloon angioplasty. It is best if the wires

meet along the length of the occlusion and not

proximal or distal to the occlusion. is preserves

collaterals proximal and distal to the occlusion.

Figure25.14 demonstrates dierent ways in which

balloon angioplasty can be used to disrupt the tis-

sue between the two wires that have been passed

using a bidirectional approach. Aer the tissue

between the planes has been disrupted, the retro-

grade wire is passed into the antegrade catheter to

permit through-and-through wire access.

Other tools to treat infrainguinal

disease

Other tools for revascularization, such as atherec-

tomy, stent–gras, and modied balloons, are dis-

cussed briey in Chapter 20. ey play some role

in infrainguinal revascularization. is is prob-

ably because no one option is dominant in terms of

clinical and technical success, aordability, or ease

of use. Whether the guidewire passage was trans-

luminal or subintimal, there are multiple options

for reconstruction of the artery. Atherectomy

provides the potential to debulk the lesion. Stent–

gras oer the most complete type of reconstruc-

tion considering the lesion is completely covered

and the new pathway is relined. Scoring and ser-

ration angioplasty will likely play a role in vessel

preparation and, possibly, as denitive therapy

in focal femoral–popliteal lesions. Cutting bal-

loon angioplasty is mostly of value for stenoses in

infrainguinal vein gras.

Atherectomy catheters are discussed in

Chapter20. Atherectomy may be directional, rota-

tional, or orbital. Atherectomy plays a particularly

important role in patients with heavily calcied

lesions. Atherectomy may be performed with

the concomitant use of a distal protection device

(Figure 25.15). Most operators use atherectomy for

reconstruction in areas where stent placement is

not desirable. ese include the common femoral

artery, profunda femoris artery origin, the proxi-

mal SFA, and also the popliteal artery segment

(from the adductor canal to the popliteal artery).

Atherectomy catheters pass over a 0.014-inch

guidewire. e tip of the sheath is placed close

to the lesion. e catheter is advanced over the

guidewire in its nonengaged state. When using

directional atherectomy, the catheter is with-

drawn and oriented so that the cutting chamber

B C

E F

Fig. 25.12 Using a re-entry catheter. (A) The

guidewire and catheter have been advanced

along the subintimal space but are unableto

re-enter. (B) The guidewire and catheter are

advanced in the subintimal space past the lesion.

subintimal space along a segment of artery

that is even with the true lumen. (D)Are-entry

catheter is advanced, in this case an Outback

catheter, and oriented toward the true lumen.

(E) The needle on the tip of the catheter

is deployed. (F) The 0.014-inch guidewire

isadvanced into the true lumen. The needle is

withdrawn and the re-entry catheter removed,

leaving the wire in place.

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Femoral–popliteal occlusive disease 361

A B C D E F

Fig. 25.13 Bidirectional approach to femoral–popliteal disease. (A) In this example, a long segment

of femoral–popliteal occlusion presents. Long segment lesions are less likely to be crossed from an

antegrade direction alone. (B) A sheath is placed from an antegrade direction and a wire advanced

supported by a catheter. (C) Antegrade advancement of the wire fails. There are numerous directions

in which the advancing wire may course. (D) A retrograde puncture and access are performed. In this

example the posterior tibial artery is the access site. The retrograde wire is advanced into the distal

cap and the occlusion. The wire is supported by a low-proﬁle CTO catheter. (E) In order to assist in

getting the wires into the same plane, balloon angioplasty is performed through the proximal sheath.

(F) The distal wire is advanced into the proximally placed catheter.

A B C D

Fig. 25.14 Recanalization of an occlusion using bidirectional angioplasty. (A) The proximal sheath is a

platform for passing any angioplasty balloon that is required. In this example, the angioplasty balloon

has been passed into the occlusion. A retrograde wire has been passed near the tip of the proximally

placed balloon. If angioplasty from the proximal direction is not adequate to disrupt the interven-

ing tissue and allow the wires to meet in the same plane, a low-proﬁle balloon can be introduced

over the retrograde wire. (B) A retrograde balloon has been introduced. The tips of the balloons are

juxtaposed. (C) An enlarged version of the mechanism shown in the wires on which the balloons are

mounted extend into the zone of the angioplasty provided by the opposing balloon. The wires act

as blades to cut through the tissue that separates the different planes. The tips of the balloons also

oppose each other to disrupt the tissue. (D) If the tissue is still present, the balloons can be advanced

again just past each other and reinﬂated.

https://t.me/med1917

362 Complex lower extremity revascularization

faces the plaque. On engaging the cutting motor,

the angle created in the catheter fully exposes

the cutting chamber. e device is advanced very

slowly alongthe artery. Despite attempts to remain

steady, there are segments of plaque where the

device skips a bit. is is not surprising since a very

heterogeneous substance is being cut. It is best to

start cutting 1–2 mm proximal to the lesion and to

conclude cutting 2 mm distal to the lesion. Aer

cutting in one orientation, the cutting chamber is

closed, the catheter withdrawn and reoriented in

another direction, and another cut is performed.

Usually, aer a few cuts, depending on how long

the lesion is, the chamber becomes full and the

catheter is withdrawn to clean the chamber. Aer

several cuts, angiography is performed. If possible,

the atherectomy device is used as the sole method

of reconstruction, but sometimes it requires stent

placement to treat loose aps. Rotational or orbital

atherectomy is performed by advancing the lead-

ing burr or sanding device over the 0.014-inch wire

close to the lesion. e motor is engaged and the

burr advanced slowly across the lesion, as slow as

1 mm per second. e progress of the device can

also be observed intermittently under uoroscopy.

ere is also signicant auditory feedback as the

burr encounters more heavily calcied plaque. e

same passage across the lesion can also be made

again at a higher speed, which allows a larger

lumen to be created. ere is typically a limit for

each device on how long a period of continuous

sanding is permissible. In order to keep the burr

in the appropriate line of the vessel, the guidewire

should be passed at least 5 cm, if possible, beyond

where the burr will engage the lesion. Aer several

passes, angiography is performed. e operator

must then decide on whether additional atherec-

tomy is required or if additional maneuvers such

as angioplasty or stenting is needed.

Another debulking option is excimer laser-

assisted angioplasty. e excimer laser is useful for

recanalizing occlusions and burring holes through

occlusions that will assist in guidewire place-

ment using a step-by-step approach with the wire.

A B C D E

Fig. 25.15 Using a distal embolic protection device. (A) An embolizing femoral–popliteal artery lesion

is identiﬁed by arteriography. (B) A free-wire system is used. The designated guidewire is passed

beyond the lesion and into the tibial runoff. (C) An Emboshield

ﬁlter is passed beyond the lesion and

deployed proximal to the trifurcation. The guidewire is permitted to ﬂoat distally in the tibial artery.

(D) Another free-wire ﬁlter choice is the SpiderRX™ ﬁlter. (E) After treatment of the lesion, a ﬁlter

capturing catheter is placed to retrieve the ﬁlter.

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Femoral–popliteal occlusive disease 363

eexcimer laser is also useful in debulking super-

cial femoral, popliteal, and tibial artery lesions.

One major advantage of the excimer laser over the

atherectomy device is that the excimer laser is a

bit faster and it can also be used to dissolve some

emboli if they should occur during the process of

debulking. e laser may be passed more than once

at progressively higher power levels, but it achieves a

proscribed diameter of the artery, based on the size

of the catheter and whether a turbo booster is used.

Another method of reconstruction is to place

one or more stent–gras. e Viabahn

™

stent–

gra has an SFA indication and is the most widely

used in practice. One major advantage of the

Viabahn

™

is that the luminal ow surface is com-

pletely relined and the damaged or diseased ow

surface is excluded. In-stent restenosis is limited

because it is not possible for intimal hyperplastic

tissue to grow through the gra itself. Restenosis

may occur at the end of the gra. e Viabahn

™

stent–gra requires a slightly larger sheath so

this must be planned during sheath placement.

Viabahn

™

gras may be placed in a manner that

cover the collaterals and this should be avoided, if

possible. If the gra fails at a later time, it might

go into a fast fail mode where the outow throm-

boses when the gra goes down. Viabahn

™

stent–

gras may be used as an alternative to stenting in

the SFA and popliteal artery. If the stent–gra is

oversized too much, there is a potential for wrin-

kling and bunching of the material, so the sizing

in the instructions for use must be followed. Aer

placement, balloon angioplasty is performed, not

with an oversized balloon but with one that is

sized to the gra. Balloon angioplasty is restricted

to the length of the gra itself, to avoid dissection

along adjoining segments of artery. If more than

one stent–gra is required, major overlaps in the

devices will leave a lot of excess material in the

lumen, so this should be minimized. Stent–gras

may be placed across the knee joint in the treat-

ment of popliteal aneurysms, but this maneuver is

not as acceptable for occlusive disease.

Scoring angioplasty or serration angioplasty

should be considered in calcied arteries, re-

stenosis, or for overall improvement in angioplasty

results. Cutting balloon angioplasty works for

infrainguinal vein gra stenosis (Figure 25.16).

is tends to be composed of intimal hyperplas-

tic tissue, which is focal in the gra. e tip of the

sheath is placed close to the gra origin and the

patient is anticoagulated. A 0.014-inch guidewire is

passed into the gra and across the lesion. Balloon

ination with a cutting balloon is performed

slowly and with an undersized balloon. A stan-

dard angioplasty balloon of the size desired for the

nished diameter is placed to further enlarge the

gra. Focal tibial artery lesions and focal but heav-

ily calcied lesions of the supercial femoral and

popliteal arteries may also be treated with scoring

or serrating balloon angioplasty.

What is vessel preparation?

It has become clear, through a variety of trials

and dierent clinical experiences with the vari-

ous denitive therapies available, including drug-

coated balloon angioplasty, self-expanding nitinol

stents, drug-eluting stents, stent–gras, and woven

nitinol stents, that preparing the artery prior to

therapy will play a key role in the results.

Vessel preparation has not been perfectly

dened. Some of the features included in vessel

preparation are lumen gain, minimizing arterial

wall defects such as dissection, preparation of the

tissue for drug delivery, and improvement in vessel

compliance. In some of the pivotal trials of drug-

coated balloons, patients with poor results aer

vessel preparation with plain balloon angioplasty

were excluded. is is because patients with severe

postangioplasty dissections require additional

measures to manage dissections. Calcium has also

been shown to be a barrier to medication uptake.

Vessel preparation is probably also essential to

achieving best results in calcied arteries.

Methods of vessel preparation include the use

of plain balloon angioplasty, modied angioplasty

balloons, and dierent types of atherectomy. At

present, the most common method of vessel prepa-

ration is careful and prolonged predilation with a

plain balloon. A plain balloon, 1 mm smaller than

the intended reference vessel diameter or the same

size as the intended reference vessel diameter, is

used with a slow ination time and maintaining

balloon ination for 2–3 minutes. Various types of

modied balloons may also be used in an eort to

create a lumen without extensive dissection. ese

include balloons with spiral wires or longitudinal

wires or serrating balloons that create serration for

even distribution of angioplasty energy and por-

tals for medication uptake. Although vessel prepa-

ration (“vessel prep”) is not yet clearly dened, this

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