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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3585_Библиотеки_им_академика_М_И_Перельмана
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a
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c
POBA POBA NSE POBA NSE POBA POBA NSE NSE NSE
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Fig. 2.28 Bifurcation lesion with calcied plaque. In
a bifurcation lesion with calcied plaque (a),
alternating balloon ination appears to have
sufciently dilated both the MB and SB, since there
are no indentations when the balloon is inated in
either branch (b). However, alternating balloon
ination has caused carina shift and deformation of the
SB shoulder, which have transiently eliminated the
indentations in the body of the SB balloon so that the
SB ostium seems to have been dilated sufciently (b).
During KBI, one or more indentations may reappear in
the body of the balloon (c). In this setting, it is
uncertain whether such indentations can be eliminated
by raising the KBI pressure. Since high- pressure KBI
is associated with a signicant risk of dissection or
perforation, performing KBI with two scoring balloons
(e.g., a Lacrosse NSE) at a low pressure is better
2 Stenting ofBifurcation Lesions
Fig. 2.29 Optimal selection
of scoring balloon angioplasty
or POBA according to the
severity of stenosis and
calcication
Bifurcation lesions should be adequately prepared by
appropriate use of a scoring balloon (e.g., a Lacrosse NSE)
as required. The scoring balloon should usually be onequarter size smaller than the diameter of the target vessel
2.3.2 KBI forPost-dilatation
Except in these situations, stenting should generally be
followed by KBI.If the proximal MB has a large diameter,
POT should be performed before nal KBI.The reasons for
this recommendation are as follows: (1) POT alone cannot
achieve sufcient dilation of a bifurcation, including the
carina (accurate POT is possible for an LAD-Dg ostial lesion
that can be viewed en face on angiograms, but not for an
LM-LAD-LCX lesion that is difcult or sometimes impos-
Even if the side branch is protected with a guidewire, KBI
may not need to be performed for pre-dilatation or postdilatation in the following situations: (1) if the SB has a relatively small diameter (<2.0mm) and only perfuses a small
territory (Fig. 2.30), (2) if the proximal MB has a similar
diameter to the distal MB, (3) if there is little plaque at the
ostium of the SB, (4) if coronary angiography shows no signicant stenosis at the SB ostium after stenting or POT of a
LAD-Dg bifurcation lesion, and (5) if SB blood ow does
not decrease after removal of the SB guidewire or after high-
sible to view en face). (2) An attempt to perform POT along
the carina without knowing its true position may lead to
over-dilatation and injure the proximal segment of the distal
MB. (3) A balloon employed for POT, even if it reaches the
carina, cannot be used to evenly dilate the proximal MB if
plaques show maldistribution in this segment. (4) Considering
that the proximal MB originally has an elliptical lumen, POT
should be combined with KBI to dilate the proximal MB to
an ellipse and thus achieve complete stent apposition
(Fig.2.31).
pressure balloon ination in the SB.
KBIPOTAfter stent implantation
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KBI (+) KBI (-)
*1
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*2
*3
Fig. 2.30 A situation where KBI may not be required. In a bifurcation
with a small SB <2mm in diameter (*1, *2), only guidewire protection
is adequate without addition of KBI if there is no decrease of blood ow
through the SB after stenting (+ post-dilatation). However, KBI should
be considered if the SB is larger and perfuses a large territory (*3)
Column 14 Selection of the Balloon Type and Ination Pressure
Fig. 2.31 Achieving complete stent apposition. Since the proximal
MB has an elliptical lumen, POT combined with KBI should be used to
dilate the proximal MB to an ellipse and thus achieve complete stent
apposition
Here, I will explain my ideas about how to select the ideal type of balloon (including stent) and the ideal balloon size, as
well as how to determine the balloon ination pressure. These points are also applicable to PCI for non-bifurcation lesions.
For pre-dilatation, you should basically choose a slightly undersized balloon that can be inated to the desired diameter at its rated burst pressure plus 4atm. You should steadily pre-dilate the lesion to adequately prepare it for stenting
while preventing stent edge dissection due to over-dilatation of the lesion. If the lesion is severely calcied and is not
dilated sufciently by POBA (even after rotablation), you should perform scoring balloon or cutting balloon angioplasty, since this is the best way to completely avoid suboptimal dilatation after stenting. The Lacrosse NSE balloon for
this purpose should be one-quarter size smaller than the diameter of the target vessel, so that it can be inated to the
optimal size at its RBP plus 4atm. The balloon ination pressure should generally be escalated to the RBP plus 4atm.
The optimal balloon size depends on the situation. To determine the optimal size, you should assess the risk/benet
ratio by considering the vessel diameter (external elastic membrane), inner diameter, and plaque eccentricity (particularly calcied plaques).
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c
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2 Stenting ofBifurcation Lesions
2.3.3 Basic Procedures forStenting withKBI
proximal to the bifurcation. Orient the tip of the SB guidewire toward the SB (Fig.2.32c) and slowly pull it back
2.3.3.1 SB Rewiring
There are three key points to keep in mind when recrossing a
guidewire into the SB again across the MB stent.
while maintaining this orientation. A guidewire that has
been pre-shaped with an optimal tip curve (Fig.2.32d★)
is better able to cross into the SB through the most distal
cell at the bifurcation.
Dual Lumen Catheter (Crusade Catheter)
The Crusade catheter is used for SB (MB) wiring. If SB wir-
4. If the guidewire crosses the stent to reach the SB, you can
advance it into the branch (Fig.2.32e).
ing is performed before stent implantation, the bare wire
technique can generally be employed. If SB wiring is found
to be difcult after MB wiring or if MB wiring is difcult
after SB wiring (intentionally done before MB wiring), you
should advance a Crusade catheter over the rst guidewire. If
If the stent has an open cell design, it is optimal for the SB
guidewire to cross the MB stent into the SB through the most
distal cell near the carina, or it should cross through the cell at
the center of the SB lumen if the stent has a closed cell design.
you are treating a bifurcation lesion distal to a long CIO, you
should also use the Crusade catheter for SB wiring.
I always use a Crusade catheter for SB wiring after MB
stenting. Although some interventionalists may criticize the
overuse of limited medical resources, employing the Crusade
catheter ensures wire crossing through the optimal cell of the
stent, thus reducing the risk of SB jailing and difculty
implanting a stent in the SB.It also alleviates possible problems related to future SB intervention.
The Crusade catheter is also advantageous for SB wiring
after ostial dissection or occlusion of the SB.If a Crusade is
not used (bare wire technique), SB wiring will be difcult
because the guidewire tip tends to become stuck on the proximal stent struts. Attempts at SB wiring by using a single
guidewire with its original tip shape tend to fail and may
rather enlarge the dissection. If you use a Crusade catheter,
SB wiring can be retried many times by advancing the guidewire from the tip of the catheter, and there is no stress on the
wire from the proximal part of the stent. The Crusade also
facilitates SB rewiring by using the same guidewire after
modifying the tip shape or with a different guidewire. Thus,
the Crusade catheter is useful for SB rewiring in most occlusions with most types of dissection.
Overall, use of the Crusade catheter improves the quality
of PCI and eventually reduces the impact on medical
resources.
R
Using a Crusade Catheter (SB Wiring After Stenting)
1. You should insert an SB guidewire into the over-the-
wire (OTW) lumen of the Crusade catheter (but do not
allow the tip to protrude from the catheter) and advance
the Crusade along the MB guidewire in the stent
(Fig.2.32a).
2. Advance the tip of the SB guidewire through a side hole
at the tip of the OTW lumen to reliably place the guide-
wire tip distal to the SB ostium in the stent (Fig.2.32b).
3. While keeping the two guidewires in place, you should
pull the Crusade catheter back so that its tip is 1–2 cm
R+1~1.5 mm
Fig. 2.32 Using the Crusade catheter (a–e)
GW
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Removing the Crusade Catheter
1. Trapping technique (Fig.2.33)
While maintaining the two guidewires in position, withdraw the Crusade catheter into the guiding catheter. Introduce
a Kusabi® trapping balloon or a large-diameter (2.0 to
2.5mm) balloon catheter directly into the guiding catheter.
Inate the balloon at about 10atm to trap the two guidewires
and pull them back together with the balloon catheter. Never
fail to remove the air trapped in the guiding catheter after
deating the balloon. This is the safest and most reliable
method for removing the Crusade.
2. Nanto’s technique (Fig.2.34)
This technique involves xing the guidewire in the monorail lumen and removing the Crusade catheter while advancing the guidewire in the OTW lumen. It is safer to use an
ination device (indeator) to advance the guidewire. I prefer this technique because it is quicker than the trapping
technique.
1. First, you x the guidewire in the monorail lumen of the
Crusade catheter. While checking the position of the tip
of the guidewire in the OTW lumen by cineangiography,
pull the hub of the Crusade catheter back to the proximal
end of the OTW guidewire.
2. Monitor the pressure waveform and conrm that the cath-
eter is not wedged in the vessel. If the catheter becomes
wedged, air may be aspirated, or air that unexpectedly
enters the vessel from an ination device may not be let
out, possibly leading to air embolization.
3. Completely remove air from the ination device and con-
rm that the wire passes through the center of the ina-
tion device connector and is not caught by the connector.
Then connect the ination device to the Crusade
catheter.
4. Apply pressure on the OTW lumen of the catheter by
using the ination device.
5. In reaction to the advancing OTW guidewire, the Crusade
catheter will move back through the guiding catheter. To
prevent unexpected air embolization, keep the O-ring of
the Y-connector open.
6. You must continue to hold the guidewire in the monorail
lumen with your left hand or the guidewire will come out
spontaneously. Place your right hand lightly on the
Crusade catheter to support it.
7. When removing the Crusade catheter, the exit port of its
monorail lumen will get stuck on your left hand. While
continuing to apply pressure on the OTW lumen, move
your left hand to a more proximal part of the monorail
lumen guidewire. Then slowly withdraw the Crusade
catheter while monitoring the position of the OTW lumen
guidewire by cineangiography to conrm that it is still in
place. When the exit port of its monorail lumen gets stuck
on your left hand again, stop removing the catheter and
repeat the above procedure. As is done during removal of
monorail (rapid exchange) devices, you continue to apply
pressure on the OTW lumen and to hold the Crusade
catheter.
8. When the tip of the Crusade catheter exits the Y- connector,
you reduce the pressure on the OTW lumen to atmospheric
pressure. Carefully hold and x the guidewires in both
lumens near the O-ring and remove the Crusade catheter.
9. If a jailed guidewire remains after SB rewiring, it must be
the third guidewire (not the two guidewires you are holding). Remove the jailed guidewire as soon as possible
after removing the Crusade catheter (after the wire is conrmed to be jailed).
3. Extension wire technique
This technique involves xing the guidewire in the mono-
rail lumen, xing the guidewire extended by an extension
wire or guidewire, and removing the Crusade catheter.
I do not use this technique because of the complexity of
the procedures required to simultaneously x the two
guidewires.
Fig. 2.33 Trapping technique. This technique requires a Kusabi trap-
ping balloon or a large-diameter (2.0–2.5mm) balloon
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Fig. 2.34 Nanto’s technique
Column 15 Preventing Guidewire Entanglement and Countermeasures
2 Stenting ofBifurcation Lesions
22446688
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[Crusade catheter]
Using a Crusade catheter to facilitate SB wiring also contributes to preventing guidewire entanglement. A Crusade
catheter allows delivery of a guidewire within its OTW lumen beyond the carina, which is associated with a much
lower risk of guidewire entanglement compared with the bare wire method.
[Organizing guidewires]
Organizing the guidewires is also important to prevent entanglement. I recommend organizing your guidewires in the
order of the directions in which they are viewed by uoroscopy. Two kissing balloons are difcult to withdraw individually because the other may also be withdrawn spontaneously while removing one balloon. However, simultaneous withdrawal of two kissing balloons may disturb the organization of your guidewires. Therefore, I recommend reorganizing the
two guidewires by separating their proximal parts while keeping the topological relationship at the O-ring. The same
applies to wiring with the assistance of a Crusade. You should put the proximal parts of the two guidewires in the correct
order while keeping their topological relationship at the O-ring, and cover them with wet gauze for stabilization.
[Countermeasures for entanglement]
1. Case 1
The rst device (e.g., balloon and stent) to be delivered into the MB may not go beyond the bifurcation due to
guidewire entanglement. In this case, you should pull the device back to the hub and advance it again, which often
allows you to successfully deliver the device into the MB.If this maneuver fails, retract the guidewire into the device
and then push it gently forward while slightly pressing the device into the bifurcation. The device will often become
disentangled, permitting it to advance beyond the bifurcation.
2. Case 2
A previously inated balloon may become entangled due to poor rewrapping of the balloon or twisting of the shaft.
Therefore, I recommend selecting a balloon that rewraps well with a shaft that is strong near the exit port. A balloon
that has become entangled should be exchanged for a new one, which can often be delivered smoothly
3. Blocking of the second device by the guidewire exit port of the rst device
The guidewire exit port of a device that has already been advanced into the guiding catheter may block advancement
of a second device. In such a situation, you should pull the latter device back to the hub and then advance it again. This
maneuver often allows the device to be delivered successfully. If it fails, you should withdraw both devices and then
readvance them simultaneously.
a
c
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2.3.3.2 Optimal Projections
The optimal projection for visualizing each coronary bifurcation should permit en face observation of the plane in
which both the MB and SB lie (Fig.2.35). However, it is not
Fig. 2.35 Optimal
projections. CAG guidance
(a) using a projection that
deviates considerably from
that perpendicular to the plane
of the MB and SB (b or d)
will only allow successful
wiring of the MB or SB by
chance, since it is impossible
to assess whether the wire has
come into contact with the
carina. Conversely, CAG in a
projection perpendicular to
the plane of the two branches
(c or e) facilitates SB wiring
and assessment of whether the
guidewire has contacted the
carina
always easy to nd the specic projection for each situation,
and interventionalists can sometimes be mistaken about the
optimal projections for visualizing bifurcations.
b
e
d
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2 Stenting ofBifurcation Lesions
Examples of Wrong Projections
The most frequently chosen wrong projection is use of the
RAO cranial projection for separating the Dg from the proximal LAD.The RAO is relatively parallel to the plane of the
proximal LAD and the Dg, so the two vessels overlap in
most parts when viewed in this projection. The cranial projection is good for separating the Dg from the mid-distal
LAD, but not for visualizing the LAD-Dg bifurcation.
According to standard practice, the LAO cranial projection is
optimal for separating the Dg from the proximal
LAD.Figure2.36 shows typical CAGs explaining this point.
It is easy to understand that the longest view of the LAD is
obtained in the cranial projection as this artery runs leftward
and anteriorly. The Dg is located posterior to the LAD and
left of the LAD in the AP cranial view. The LAO projection
is excellent for visualizing a bifurcation with leftward and
posterior SB angulation. As the longitudinal axis of the LAD
is oriented anteriorly, marked cranial angulation is better.
The LAO cranial projection separates the Dg from the LAD
very well (Fig.2.36c). If the LAD takes extremely anterior
course, even greater cranial angulation may be needed to
achieve good separation from the LCX, but such a projection
imposes stricter radiographic conditions. Some interventionalists prefer the RAO cranial projection, probably because
this projection had better radiographic conditions and provides clearer images than the LAO view. However, the RAO
cranial projection is not optimal for visualizing the LAD-Dg
bifurcation.
runs caudally in the LL cranial projection, while it is on the
a bc
Fig. 2.36 Optimal projection for separating the Dg from the LAD. (a) AP cranial view. (b) AP/LL view. (c) LAO cranial view. The LAO cranial
projection is optimal for separating the Dg from the LAD
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Typical Projections Allowing En Face Observation of
Various Coronary Bifurcations (Table2.1)
The projections presented in the table often allow the SB to
be separated from the MB at individual bifurcations and
should be tried rst. If the recommended projection is not
appropriate, you will generally need to adjust the uoroscopy angle to optimize it.
The bifurcation of LMT to form the LAD and the LCX is
a special case. At other coronary bifurcations, the two
branches run in the same plane on the surface of the ventricle
for some distance, so it is relatively easy to identify the plane
dicular to that plane. However, both the LAD and the LCX
immediately change directions at the LMT bifurcation, with
the former running to the left, anteriorly and caudally, while
the latter runs posteriorly. The LM bifurcation offers a point
of deection for both branches. In other words, there is no
plane which encompasses even the proximal segments of
both the LAD and LCX.It is hard to nd the optimal projection for visualizing the LMT bifurcation by reviewing various images of the proximal LAD/LCX, so you have to
estimate the take-off angle of each branch. This is sometimes
difcult and requires many ne adjustments.
encompassing both branches and nd a projection perpen-
Table 2.1 Projections allowing en face observation of different coronary bifurcations
Coronary bifurcation Projection perpendicular to the bifurcation plane Ancillary projection for biplane cineangiography
LAD and LCX LAO+CA(spider) AP(RAO)+CA
LAD and Dg(Prox) LAO+CR AP+CR(RAO+CR)
LAD and Dg(M~Dist) LAO~AP+CR
LAD and Sept RAO+CR
LCX and PL (Prox) RAO+CA LAO+CA
LCX and PL (M) RAO
LCX and PL (Dist) RAO+CR
4-AV and 4-PD LAO+CR AP+CR
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Rules for Fine Adjustment of Fluoroscopy Angles
1. If the standard Spider view cannot separate the LCX from
the LAD, a more steeply angled LAO projection is
needed. In a view with more caudal angulation, the LMTLAD often becomes “elevated” and easier to distinguish
2. When performing biplane coronary angiography of a
bifurcation, exploration along a line that is assumed to
connect the two branches can lead to identication of the
optimal uoroscopy angle. The two projections do not
necessarily need to be orthogonal to each other.
from the LCX (Fig.2.37).
ab
Fig. 2.37 Adjusting the Spider view. (a) LAO 44.3° and caudal 17°. In this shallow Spider view, there is poor separation of the LAD from the
LCX (occluded). (b) LAO 89.6° and caudal 37.2°. In this steeper Spider view, the LAD shows good separation from the LCX
LAD
LAD
LCX
LCX
b
a
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Reliable Method of Finding the Optimal Projection for
En Face Observation of a Specic Bifurcation
The optimal projection may be determined in an empirical
manner, as described above. However, if you have no idea
which projection will allow en face observation of the bifurcation, the following procedure can be followed to reliably
identify the correct projection. First, you should nd the projection that provides the longest view (red line) of the bifurcation (deep green) and the longitudinal axis of the MB
(green) (Fig.2.38). Then you should rotate the detector at 90
degrees around the line projected on the surface of the uoroscope. The longest view of the longitudinal axis of the MB
will be provided by the new projection, since the MB is
being viewed in a projection orthogonal to the plane of the
vessel (Fig.2.39). Subsequently, you should rotate the detector around the axis to nd a plane in which the branching
angle is maximal, i.e., a projection in which the bifurcation
can be viewed en face (Fig.2.40). The optimal projection is
not always required for simple wiring before stenting.
However, if the optimal projection is found in this way after
wiring the two branches, coronary angiography will not be
required. If SB wiring is difcult, you may leave the guidewire in the MB and inject small test doses of contrast medium
while seeking the optimal projection that displays the maximal branching angle.
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Fig. 2.39 Visualizing the longitudinal axis of the MB: 2. The longest
view of the longitudinal axis of the MB is obtained when the ROI is
seen in a projection orthogonal to the plane encompassing the axis
SB axis
Projected
longitudinal axis
FPD
SB axis
Projected
longitudinal
axis
Fig. 2.40 Finding a projection that allows en face observation of the
bifurcation plane after identifying the optimal projection for visualizing
the longitudinal axis of the MB.Assuming that the SB is viewed on the
Fig. 2.38 Visualizing the longitudinal axis of the MB: 1. The green
line represents the axis of the ROI (dark green). This axis is viewed as
the thick red line on the anterior detector. To visualize the true axis, you
rotate the detector 90 degrees around the projected axis
uoroscopy detector (FPD) as shown in (a), while the actual branching
pattern is shown in (b), a projection that is en face to the green plane
will be optimal. You should seek the green plane with the maximal
branching angle by rotating the red plane clockwise or anticlockwise
around the longitudinal axis projected on the detector. Several test
doses of contrast medium may be injected during this step
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