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294 Brachiocephalic interventions

is a stenosis or occlusion near the origin of the le

subclavian artery. e planning varies depending

on whether the lesion is on the patient’s right or le

side and whether it is located at the origin of the

artery or a location more distal.

Transfemoral approach to the

subclavian and axillary arteries

A 6-Fr or 7-Fr sheath is placed in the femoral

artery. Arch aortography is performed to iden-

tify the location of the subclavian artery. Very

oen, if the lesion is near the origin of the le

subclavian artery, it can also be located by look-

ing for its positional variation with pulsatility,

while observing with uoroscopy. If the lesion

is on the patient’s le side, a LAO projection is

best. If the lesion is on the patient’s right side, the

innominate artery is cannulated and a RAO pro-

jection performed to identify the location of the

right subclavian artery origin. Heparin is admin-

istered (75–100 U/kg). AGlidewire

is placed in

the aortic arch in exchange for the ush catheter.

An angled catheter, usually 100 cm in length with

a simple curve tip, such as a vertebral catheter, is

placed over the Glidewire

. If the origin of the

artery is relatively free of disease, the catheter is

used to cannulate the subclavian artery and the

Glidewire

is advanced. If there is a signicant

lesion at the origin of the subclavian artery, the

catheter is used to direct the Glidewire

toward

the artery orice. e Glidewire

is used to

probe the lesion with the intent of crossing it. If

the lesion at the origin of the subclavian artery is

very challenging to traverse with this relatively

unstable platform, another approach is as follows.

A 6-Fr or 7-Fr, 70-cm or 90-cm long, straight

sheath with a radiopaque tip is passed and the tip

advanced to within a few centimeters of the orice

of the subclavian artery. e dilator is removed

and the appropriate selective cerebral catheter

(see Chapter 9), 100–120 cm in length, is placed

through the sheath. e tip of the selective cath-

eter is placed beyond the end of the sheath. e

steerable guidewire probes the orice of the artery

with support and direction provided by the selec-

tive catheter. e guidewire is advanced across

the lesion and as far into the artery as possible to

provide support for the catheter to be advanced

(Figure 21.11). e catheter is advanced into the

subclavian artery. Selective arteriography may be

performed if necessary. A stier guidewire, such

as an Amplatz Super Sti

or other exchange wire,

is placed. e selective catheter is removed, the

dilator placed, and the sheath advanced into the

artery origin. Arteriography and heparin ush

administration is performed through the side arm

of the sheath.

e best lesions for angioplasty and stenting in

this area are short and located well proximal or

distal to the vertebral artery. A lesion juxtaposed

to the vertebral artery might be better treated

with open surgery. e endovascular option usu-

ally involves stent placement in the vertebral and

subclavian arteries. e balloon diameter is usu-

ally between 6 and 8 mm. e balloon catheter is

placed across the lesion. e balloon is inated and

resolution of the atherosclerotic waist is observed

using uoroscopy. Oen the location of the origin

of the subclavian artery can be visualized during

balloon ination. Because the subclavian artery is

so and a rupture in this location has potentially

disastrous consequences, it is important to avoid

overdilation. Subclavian artery orice lesions are

usually treated with balloon-expandable stents

since these lesions are oen heavily calcied and

spillover lesions from the aortic arch and the artery

are relatively xed in position at this site. Lesions

in more distal locations are best treated with self-

expanding stents, since the artery is more exible

and mobile in these areas and may be aected by

external structures and forces. Stents should be

avoided near the crossing of the rst rib and distal

to the humeral head since these are areas of very

high exibility and with potential for external

impingement.

Stent placement considerations in the subcla-

vian artery are similar to those for the common

carotid artery. Aer angioplasty, if the sheath is

in a stable position for stent placement, it is le in

position. If the position is a bit unstable, the tip of

the sheath can be advanced a centimeter, or a few

centimeters, over the actively deating balloon in

order to get the sheath into a slightly more stable

position prior to stent placement. A premounted

stent on the appropriately sized balloon with a

90–120-cm sha length is used for orice lesions

(Figure 21.11). e balloon-expandable stent size

for the proximal common carotid artery is usually

6–8 mm. e balloon and stent are passed through

the sheath and across the lesion and the stent is

deployed. Advancing the sheath across the lesion

https://t.me/med1917

The subclavian and axillary arteries 295

for stent delivery is usually not necessary as long as

the sheath tip has a secure purchase on the artery

origin and the lesion has been predilated enough

to permit passage of the catheter. Self-expanding

stents are more likely to be used in the subclavian

artery, when the lesion is distal to the origin, and

also in the axillary artery. e self-expanding stent

diameter should be 8 or 10 mm and the delivery

catheters are 120 cm in length. e delivery cath-

eter is passed through the sheath and across the

lesion, and the stent is deployed. Poststent balloon

angioplasty is performed. Completion arteriogra-

phy is performed through the sheath.

Lesions at the orice of the subclavian artery

pose similar challenges to those that occur at the

common carotid artery origin. When the sheath is

withdrawn to expose the stent, the tip of the sheath

loses its purchase on the artery. When treating this

type of lesion from a transfemoral approach, pull

the sheath back slowly and place its tip in the arch

but close to the origin of the artery. Another option

is to place the stent through a retrograde, transbra-

chial approach.

If the lesion extends to the vertebral artery, care

must be taken when deploying stents at this loca-

tion as the origin of the vertebral artery is at risk

for injury. is is also a location in the subclavian

artery where there is some signicant curvature.

A self-expanding stent may potentially be use-

ful when the lesion is distal to the origin and in a

tortuous segment of the artery. Avoid choosing a

stent that is too long; a calibrated catheter is useful

for this. To obtain the best view of the origin of the

vertebral artery, sometimes it proceeds directly

from the superior aspect of the subclavian artery but

sometimes also it comes o the posterior aspect of

the subclavian artery. A slight craniocaudal angula-

tion (5–10 degrees) may help visualize the vertebral

artery origin. Aer placement of a self-expanding

stent, the balloon may be gradually upsized so that

B C

E F

Fig. 21.11 Balloon angioplasty and stenting of the subclavian artery through a transfemoral approach.

(A) A guidewire is placed in the subclavian artery and across the lesion. (B) A long sheath is placed

with its tip in or near the origin of the subclavian artery. An angioplasty catheter is placed. (C)Balloon

angioplasty of the subclavian artery lesion is performed. (D) The stent is delivered to the site of

the lesion. (E) Stent deployment is performed. Caution is exercised during stent deployment to

avoid engaging the tip of the sheath with the stent and deployment in proximity to the origin of the

vertebral artery. (F) Completion arteriography is performed through the sheath.

https://t.me/med1917

296 Brachiocephalic interventions

the artery is gently dilated and the risk of rupture

is diminished. If the brachial approach is chosen,

the catheter is advanced from the brachial side of

the lesion and there is only really one place for this

guidewire and catheter system to go, and that is ret-

rograde directly into the lesion.

Retrograde approach to the

subclavian and axillary arteries

e transbrachial or transradial, retrograde

approach to the subclavian and axillary arteries is

direct and does not require selective catheteriza-

tion from as remote an entry site as does the trans-

femoral approach (Figure 21.12). e patient’s

ipsilateral arm is extended at the side. A work-

ing table is placed at the end of the arm board to

accommodate the guidewires and catheters. e

transbrachial approach may be performed through

either an open exposure of the artery or a percuta-

neous puncture.

e guidewire is advanced retrograde using u-

oroscopy. A 6-Fr sheath is usually required, either

30 cm or 45 cm in length. It is sometimes useful to

place a longer sheath, depending on the location of

the lesion, and to perform retrograde arteriogra-

phy through the side arm of the sheath. Heparin is

administered. e guidewire is advanced through

the lesion. When the lesion of interest is at or near

the origin of the subclavian artery, it is usually

best to place a pigtail catheter through the femoral

artery and perform arch aortography using a pres-

sure injector. Retrograde arteriography through

a short sheath is usually not possible. Aer the

guidewire is advanced across the lesion, a straight

catheter with multiple side holes may be advanced

over the wire until its tip is proximal to the lesion,

and this catheter may be used for arteriography.

If the lesion is proximal to the vertebral artery,

the guidewire must be advanced into the descend-

ing aorta to maintain adequate control at the inter-

vention site. e guidewire is directed into the

descending thoracic aorta using a selective cath-

eter with a bend at the tip. A balloon catheter with

a 75-cm sha is placed and the balloon inated.

Stenting of the orice of the subclavian artery

should be performed with a balloon-expandable

stent. A premounted balloon-expandable stent is

advanced to the origin of the artery and deployed.

Tortuous segments of the artery can be stented

with self-expanding stents, as with the transfemo-

ral approach. e sha length for self-expanding

or balloon-expandable stents through a brachial

approach is 80 cm.

Occasionally, when the lesion is juxtaposed to

the vertebral artery and an endovascular option is

better than a carotid–subclavian bypass, a subcla-

vian artery stent can be placed through a femoral

artery access and a wire and/or distal lter placed

in the vertebral artery using a brachial approach.

A B C D

Fig. 21.12 Balloon angioplasty and stenting of the subclavian artery through a transbrachial approach.

(A) A guidewire and sheath are placed through a brachial artery puncture or cutdown. (B) A balloon

catheter is advanced through the sheath and into the lesion and balloon angioplasty is performed.

performed using a retrograde approach through the sheath.

https://t.me/med1917

297

Visceral and renal artery interventions

APPROACH TO THE VISCERAL

ARTERIES

e operator must decide whether to approach the

visceral arteries through a femoral access or an upper

extremity access. e advantages of the femoral

access are that it is commonly performed, clinicians

are comfortable with the procedure, and closure

devices may be used. e development of options for

an articulated sheath has made access from an infe-

rior direction simpler for treatment of downsloping

vessels such as the superior mesenteric artery (SMA).

When the downsloping angle is severe, it may make

more sense to come from a radial artery or brachial

artery access. e distance is slightly longer, but

passage of a crossing wire and placement of a stent

become simpler when the direction of the platform

is consistent with the overall direction of the visceral

vessel being treated. In some patients, the anatomy

along the access route can be hostile. If the infra-

renal aorta or the supraceliac aorta is severely dis-

eased, this may aect the decision about which way

to approach the visceral vessels. Preoperative CTA

can be used to help make this decision. e trajec-

tory of each of the vessels on these imaging studies

can be assessed. A6.5-Fr articulating sheath, which

allows the sheath tip to be manipulated into various

degrees of curvature, is available. is is quite help-

ful in supporting visceral and renal artery treatment

since these vessels come o the aorta at an angle.

CELIAC AND SUPERIOR

MESENTERIC ARTERY

ANGIOPLASTY AND STENTING

Visceral artery stenoses or occlusions may be visu-

alized by CTA. Many are asymptomatic, but when

accompanied by abdominal pain or other signs of

visceral ischemia, they may requi re urgent treatment.

A visceral artery lesion identied on angiography

oen appears longer than it actually is. An occlusion

or stenosis usually starts at the origin of the artery

and the precise location of the origin can some-

times be dicult to identify during the procedure.

Frequently, there are hints as to where the origin of

the artery is located or if there is a beak of contrast

or a signicant amount of calcication in the area

where the artery is located. During cannulation of

the visceral arteries, imaging is best conducted with

the C-arm in a straight lateral position. e position

of the arms is problematic since in the straight lat-

eral imaging position, the upper extremities inter-

fere with the uoroscopic image. Sometimes, a steep

oblique is adequate to visualize the origins of the vis-

ceral arteries. If a lateral position of the image inten-

sier is required, the arms can be stretched above the

patient’s head or they can rest over the anterior chest

and abdomen. Balloon-expandable stents are gen-

erally used to treat these lesions since they usually

occur at the origin of the artery.

is procedure may be approached from either

a transfemoral route or a transbrachial route, as

described above (Figure 22.1). e angles for can-

nulating a ush occlusion of the SMA are fairly

unfavorable from a transfemoral route. e celiac

artery trajectory from the aorta may be perpendic-

ular, or nearly so, and if this is the case, there is no

particular advantage to one or the other approach

to an occlusion. However, if the artery is patent but

stenotic or if there is a beak of entry contrast into

the artery, then it may be possible to cannulate it

from either direction. It is usually a good idea to

undertake a preprocedure study, such as CTA,

which will indicate the location and severity of

visceral artery occlusive disease. In addition, a full

array of angle tip delivery sheaths or guide catheters

https://t.me/med1917

298 Visceral and renal artery interventions

and premounted, balloon-expandable stents should

be available, including low-prole systems.

Systemic anticoagulation is administered.

A ush paravisceral aortogram is obtained. e

location of the origin of the visceral vessel of inter-

est is identied. A sheath is placed, which is usu-

ally 6-Fr in diameter, and this sheath may have an

angled tip, a curved or renal double curve (RDC)

shape, or it may be straight. e length of the sheath

must be adequate so that the tip of the sheath is

near the origin of the vessel. If a challenging angle

is present during a transfemoral approach, consider

using a curved sheath or guiding catheter such as

a RDC or inferior mesenteric artery (IMA) shape.

From the brachial route, a straight or hockey stick-

shaped sheath tip is used. Aer sheath placement,

the appropriately curved or angled 4-Fr or 5-Fr

catheter is placed (Figure 22.2).

e advantage of a more dramatically curved

catheter is t hat it gives more angulation to the trajec-

tory of the guidewire as attempts are made to can-

nulate an aortic side branch with an abrupt angle.

e disadvantage of the more curved catheter is

that as the guidewire enters the lesion, the catheter

may buckle in an unfavorable way and create insta-

bility in the system. A catheter that is well shaped

to cannulate may be dierent from one that is well

shaped to follow. If the origin of the artery is identi-

able and open, the catheter is used to cannulate it.

If there is a ush occlusion, the catheter and sheath

are used to support the wire as it is used to probe

for the opening through the lesion. Sometimes, a

0.014-inch guidewire with the lowest possible pro-

le is required for this task. Aer the guidewire is

in place, the catheter must be exchanged out, and

in this setting the curvature in the catheter may

attempt to drag the wire out of the artery. e

artery may be cannulated using either a 0.014- or

0.035-inch steerable guidewire. Choose the catheter

with the least amount of curve needed to make the

gap from the tip of the sheath to the origin of the

diseased artery. Oen, it becomes apparent that

it is helpful to withdraw the sheath a little bit to

allow the catheter to take its full shape and have a

full degree of mobility when attempting to cannu-

late the artery. If it transpires that this position is

Fig. 22.1 Considerations for proxi-

mal versus distal approach to the

visceral arteries. (A) A lateral view

of the celiac and superior mesen-

teric arteries is demonstrated. In

patients with standard anatomy, the

sheath approach can be either from

a proximal or distal direction. (B) In

situations where the visceral arteries

have an acute angle of origin from the

aorta, with a severely downsloping

trajectory, a proximal approach may

make the entire procedure simpler.

celiac aorta is severely diseased or

aneurysmal, or has signiﬁcant mural

thrombus associated with it, it is usu-

ally safer to approach the visceral ves-

sels from an inferior direction. (D) In

situations where the infrarenal aorta is

severely diseased and there is a large

amount of pararenal atherosclerosis

or mural thrombus, it is usually safer

to approach the visceral vessels from

a proximal direction through an upper

extremity access.

https://t.me/med1917

Celiac and superior mesenteric artery angioplasty and stenting 299

not supportive enough, usually the sheath can be

advanced directly over the catheter with the guide-

wire in it and protruding. e “no touch” technique

is frequently employed when an artery origin lesion

is present. When the lesion is slightly farther from

the origin of the artery so that there is a stump of

relatively nondiseased vessel, cannulation is usu-

ally a simpler procedure. e opening of the artery

is cannulated with the catheter rst and then the

wire is placed through that location. Once the wire

is in the lesion, care must be taken as the lesion is

being crossed not to catch the wire on any undesir-

able locations or create a subintimal channel. Keep

in mind that the shape of the catheter will change

as a longer distance of guidewire and a stier por-

tion of the wire is passed through the lesion and

also through the catheter head. Once the guidewire

is across the lesion, the same catheter can usually

be used to exchange for a more favorable guidewire

with which to perform the stent placement. As in

the case of other aortic branch lesions, the celiac

artery and SMA can be treated using either a 0.035

system or a lower-prole system (i.e., 0.014- or

0.018-inch diameter system).

e advantage of the 0.014-inch diameter system

is that the sheath required is not quite as large and

despite using a 6-Fr sheath or even a 5-Fr sheath,

you can consistently obtain interim angiographic

images by injecting contrast through the side arm

of the sheath and around the treatment catheters.

e other advantage of the small caliber system is

that low-prole balloons and stents are more likely

to make any sharp turns in the access sheath and

pass across the lesion since they are so much lower

prole. e 0.035 systems frequently require pre-

dilation in order to pass the stent into the lesion.

e advantage of the 0.035 system is that it can be

used with a larger and very sti guidewire, which

can make the whole system, including the guiding

sheath or guiding catheter, quite a bit more stable.

e wire length accommodated by the celiac artery

is usually shorter than the SMA. e celiac artery

and its branches are shorter and a lot more tortu-

ous. Aer feeding a certain length of guidewire into

a tortuous artery, there is usually a build-up of ten-

sion and eventually push back against the wire. In

the SMA, there is usually a relatively lengthy seg-

ment distal to the lesion. is makes the system

more stable. However, the usually fairly severe angle

of origin from the aorta increases the tension and

makes the system comparatively a little less stable.

Once the guidewire is across the lesion, care

must be taken to ensure that it is actually in the cor-

rect location. Even if it is in the correct artery, care

must be taken to ensure that it has not gone into

some small branch or collateral branch out of the

main artery just distal to the lesion. With regard to

the SMA, a le anterior oblique (LAO) projection is

oen best to follow the guidewire since the artery

tends to extend anteriorly and toward the right at

its root. With regard to the celiac artery, a straight

lateral or steep oblique is usually best to follow the

wire, but a substantial amount of image quality

is lost in doing this since you are shooting X-rays

through the wider part of the person from one side

laterally to the other. e wire going into the SMA

can extend for many centimeters distal to the lesion

and into the distal SMA, and this can provide a

fairly good rail over which to work (Figure 22.3).

An alternative method of access is demon-

strated in Figure 22.4. Steerable guide sheaths are

available that signicantly improve the ability to

place a sheath into an inferiorly slanting visceral

A B

Fig. 22.2 Catheterization of the celiac and supe-

rior mesenteric arteries. (A) A hook-shaped cath-

eter is selected. The image intensiﬁer is placed in

the lateral or near lateral position. Thecatheter

tip is used to engage the oriﬁce of the artery.

A 0.035-inch Glidewire

or a low- proﬁle guide-

wire (0.018 or 0.014 inch) is advanced. The celiac

artery is usually short and the guidewire tip

usually ﬁnds an early branch of the artery and

follows a curving path. Guidewire placement in

the SMA usually follows a straighter, diagonal

and downward course. (B) After the catheter tip

is engaged and the wire advanced, the catheter

shaft is withdrawn slightly and the tip usually

engages and slides into the visceral artery.

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300 Visceral and renal artery interventions

A B C

D E

Fig. 22.3 Stenting of a superior mesenteric artery lesion. (A) The guiding sheath or catheter is

advanced so that its tip is in proximity to the SMA. A hook-shaped angiographic catheter is placed.

(B) A 0.014-inch guidewire is advanced. The angiographic catheter is used to support and direct

the guidewire. (C) The catheter is removed. The guidewire is advanced into a stable position.

(D)A premounted, low-proﬁle, balloon-expandable stent is advanced directly into the lesion.

(E)Thestent is placed at the oriﬁce of the artery.

Fig. 22.4 Use of a steerable guide sheath to access the superior mesenteric artery. Shown is a 6.5-Fr

sheath that offers the operator the opportunity to control the shape of the sheath in one direction,

providing angulation on the basis of a control knob.

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Celiac and superior mesenteric artery angioplasty and stenting 301

vessel using a femoral approach. e steerable

guide sheath may also be used in the same manner

when approaching the renal arteries.

e celiac artery has some technical dier-

ences that distinguish it from the SMA. e artery

begins to make turns immediately aer its origin.

It is not at all uncommon to place the guidewire

within the celiac artery and for it to be only within

the artery for a few centimeters before it encoun-

ters resistance due to the tortuosity of the branches

of the artery. e celiac artery is usually quite short

and this requires great accuracy in placing stents.

e celiac artery also usually has an early branch

point with an abrupt change in caliber and is more

likely than the SMA to exhibit poststenotic dila-

tion. ere is usually no available length of celiac

artery in which the access sheath can be seeded.

Try to choose the best celiac artery branch to pro-

vide stability. Once the guidewire is in place, the

right length and diameter of stent must be selected

and placed in the right spot so that the trailing

end of the stent is ush with the aorta or protrud-

ing slightly into the aorta so that the entire lesion

may be treated. Because the celiac artery is oen

so short, the lesion may be the whole length of the

celiac artery, with branches immediately distal to

that. Usual stent lengths in the celiac artery are

12–18 mm, rarely longer. e usual stent diameter

is 6–8 mm. Aer stent placement, follow up with

poststent angioplasty. If the artery is very short

and the distal end of the lesion is very close to

the branches, it is occasionally necessary to place

a couple of guidewires into dierent celiac artery

branches. SMA treatment likewise has its nuances.

Passage of the stent through the bend from the

aorta into the SMA is sometimes dicult. e

combination of the angle and a tight lesion make

it more likely than the celiac artery to require pre-

dilation prior to stent placement. Poststenotic dila-

tion is less likely but can denitely happen and the

stent should not be matched to this diameter. SMA

stents are typically balloon-expandable and are

usually a little longer; up to 3 cm is not unusual.

e common diameters range from 6 mm to 8 mm.

ere are challenges in stent placement in the

visceral segment. Fluoroscopic image clarity is

diminished because of the depth of the location

and the thickness of the tissue that must be pen-

etrated. ere is a continuous movement of vascu-

lar structures. Bowel gas oen obscures the target

site. is is an area where heavy calcications may

occur, especially along the anterior wall at the ori-

gins of the visceral arteries and sometimes along

the posterior wall, where it is desirable to avoid

embolization by disrupting this material. If there

is a severe angle of exit from the aorta, and espe-

cially if it is a SMA or there is signicant infra-

renal pathology, then a transbrachial approach is

more desirable. It is usually best to place the tip of

the delivery sheath either inside the origin of the

artery or very close to it to support treatment.

Covered stents may also be used for treatment of

the celiac artery and SMA. ere are some data to

suggest that the patency of covered stents is better

than that of bare metal stents. ere are some low-

prole balloon-expandable covered stents that can

be used, ranging from 5 cm to 7 cm. e expected

foreshortening is a little less than with bare metal

stents. One potential advantage of covered stents is

that they remove one mechanism of intimal hyper-

plastic recurrent stenosis through the open spaces

between the struts of the stent. ere are two poten-

tial disadvantages. One is that the gra material

takes up some of the lumen. e other is that some

arteries have early branches. is is especially true

of the celiac artery, and in these situations, coverage

of branch arteries is not desirable.

If performing a transbrachial approach, place a

4-Fr access sheath in the le brachial artery using a

micropuncture needle and a 4-Fr sheath. Aerplace-

ment of a 4-Fr sheath, administer systemic antico-

agulation. A 90-cm Omni

Flush catheter is passed

along with a Glidewire

. In the arch of the aorta, the

Omni

Flush catheter is turned posteriorly and used

to direct the guidewire into the descending aorta.

e image intensier is placed in the LAO position

for this maneuver. e ush catheter is advanced

and a visceral aortogram obtained. e approximate

distance to the lesion is estimated against the length

of the catheter. A sti guidewire is passed through

the catheter and the catheter is removed. e 4-Fr

sheath is removed from the arm, dilators are used,

and then a long 6-Fr sheath is placed so that the tip of

the sheath is in the aorta near the target lesion. Once

the 6-Fr sheath is placed in the appropriate location,

oblique projections of the SMA and celiac artery can

be obtained and an angle tip, long catheter, such as

a 125-cm length 5-Fr vertebral catheter, is placed.

Aer placement of the catheter, it becomes apparent

where the tip of the sheath needs to be and the sheath

is withdrawn slightly as needed. It is not possible at

this point to advance the sheath on its own without

https://t.me/med1917

302 Visceral and renal artery interventions

the dilator and the sti guidewire and, therefore, it is

inserted beyond the point that is required and then

slightly withdrawn when the time comes. By pointing

the angle tip catheter toward the origin of either the

celiac artery or the SMA, whichever requires treat-

ment, the guidewire may then be advanced from the

tip of the catheter. e shape of the aorta oen causes

a rotational bias in the sheath. When this happens it

may point toward the lesion intended for treatment or

it may point away.

e same steps are followed as described above

when using the transfemoral route to accomplish

stent placement, with the obvious dierence of

length requirements. e major dierence in the

transfemoral route is that access site management

is a little simpler but the actual access to the visceral

artery for stenting is oen more complex due to

angulation. is is because of the extreme angles of

origin of some visceral arteries. Aer the sheath is

placed and the lesion is crossed, the sheath and the

guidewire may try to pop out during the procedure.

RENAL ANGIOPLASTY AND

STENTING

e technique of renal angioplasty and stent-

ing has been greatly simplied by the introduc-

tion of the 0.014-inch diameter systems in renal

revascularization. e renal arteries are usually

approached retrograde using a femoral access, but

an antegrade approach through a brachial puncture

site or radial access may occasionally be used when

the angle of the renal artery takeo from the aorta

is narrow or when severe aortoiliac disease prohibits

catheterization of this segment. Renal revasculariza-

tion may also be performed using an IMA-shaped

guiding catheter, with the use of a manifold device

and also the possibility of a distal protection device.

A detailed discussion of renal artery catheteriza-

tion can be found in Chapter 9. Information about

aortorenal and selective renal arteriography can be

found in Chapter 11. Supplies required for renal

artery intervention are listed in Table 22.1.

In deciding whether to treat a renal artery from

the transfemoral route or the transbrachial route,

there are a few considerations. Most of the time it

is fairly straightforward to treat a renal artery ste-

nosis from a transfemoral route. e distance is

shorter, the imaging is simpler, and the procedure

is overall safe and reliable. One disadvantage of

the transfemoral route is that there may be some

associated infrarenal aortic pathology, such as an

abdominal aortic aneurysm, mural thrombus or

atherosclerosis, or other lesion, which may substan-

tially inuence the safety of the case. If there is sig-

nicant iliac tortuosity, this will bias the catheter

Table 22.1 Supplies for renal artery intervention

Length Diameter

Guidewire Starting guidewire Bentson 145 cm 0.035 inch

Selective guidewire Magic torque 180 cm 0.035 inch (marker tip)

Grand Slam 180 cm 0.035 inch (angled tip)

Catheter Exchange guidewire Rosen 180 cm 0.014 inch (soft tip)

Flush catheter Omni

Flush 65 cm 5-Fr

Selective catheter Cobra C1, C2 65, 80 cm 5-Fr

Renal double curve 65, 80 cm 5-Fr

Renal curve 1, 2 65, 80 cm 5-Fr

SOS Omni

2 80 cm 5-Fr

Sheath Selective guide sheath Destination

angled 45 cm 6-Fr, 7-Fr

Renal double curve 55 cm 5-Fr

Balloon Balloon angioplasty catheter Balloon diameter 4, 5, 6, 7 mm

Balloon length 2, 4 cm

Catheter shaft 75 cm

Stent Balloon-expandable stent

(premounted– 0.014inch)

Stent diameter 5, 6, 7 mm

Stent length 12–29 mm

Shaft length 80 cm

https://t.me/med1917

Renal angioplasty and stenting 303

or sheath toward one side or the other and create

extra challenge. is may work to your favor if this

is the side you are treating; however, it may work

aggressively against you and serve to turn the cath-

eter and/or sheath to the opposite side to which you

desire throughout the procedure. Another situation

in which it is helpful to abandon the transfemoral

route and go with the transbrachial or transradial

route is when there is a severe and acute angle of

takeo of the renal artery so that it is signicantly

downsloping, similar to a SMA. Although this

is usually possible to do through a transfemoral

route, having a critical or even preocclusive lesion

near the origin of the renal artery is sometimes

extremely dicult to cannulate when coming from

the transfemoral route. e combination of a criti-

cal lesion that must be crossed and a severe angu-

lation at nearly the same location can make access

and stability of the platform challenging. Aer the

guidewire is across the lesion, the more angulated

the approach, due to the curvature imposed by the

turn from the aorta into the renal artery, the less

stable the system and the less pushability and track-

ability the operator has. Usually, a low-prole sys-

tem using an 0.014- or 0.018-inch platform works

best. A low-prole system also facilitates the possi-

bility of using a rapid exchange system and primary

stenting with fewer exchanges.

Aer retrograde femoral puncture, the guidewire

is passed to t he level above the upper abdominalaorta.

A 4-Fr or 5-Fr ush catheter is placed and the guide-

wire removed. e catheter head is placed at the junc-

tion of the rst and second lumbar vertebral bodies. It

is best to perform a complete aortoiliac arteriography

if renal function permits. is allows accessory renal

arteries and other variations to be identied, as well

as disease that is present along the approach to the

renal arteries. e operator then knows where other

disease is located that may potentially cause compli-

cations during intervention. Aer this is performed,

a magnied view of the aorta and renal artery origins

should be obtained. e image intensier usually

has an oblique orientation slightly toward the side of

probable intervention. Aer the image intensier is

optimally located, it is usually best to leave it in that

position until aer the artery is cannulated.

The renal arteries are unique in terms of their

mobility with breathing. The origins of the renal

arteries are relatively fixed in place bythe dia-

phragmatic crus. The renal parenchyma and

surrounding tissues within Gerota’s fascia are

mobile with diaphragmatic excursion. The result

of this anatomic arrangement is that the angle

of takeoff of the renal arteries from the aorta

varies with the ventilatory cycle. The anatomic

picture portrayed varies depending on how the

diaphragm was held during the arteriography.

Afully held breath tends to accentuate the acute

angle at the origin of the renal artery by pushing

the kidney caudad (Figure 22.5). Because the

A B C

Fig. 22.5 Renal artery position is dependent on diaphragmatic motion. (A) At full exhalation, the kidney

position is high in the retroperitoneum and the angle at the renal artery origin is affected accordingly.

(B) During mid-inhalation, the angle of takeoff at the renal artery origin becomes more acute. (C) At full

inspiration, the renal artery origin is at an even more acute angle.

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