Coronary Bifurcation Interventions Guide

Bifurcation
Intervention
- Dr. Akif Baig

 A coronary bifurcation consists of a flow divider
(carina) and three vessel segments:
 The proximal main vessel (PMV)
 The distal main vessel (DMV) and
 The side branch (SB)
Kırat T. Fundamentals of percutaneous coronary bifurcation interventions.
World J Cardiol 2022

 There is a constant relationship between these
three vessels that was identified by Murray’s law
95 years ago
(Diameter of PMV)3 = (Diameter of DMV)3 +
(Diameter of SB)3

 This law was modified by the Huo-Kassab law
as:
(Diameter of PMV)7/3 = (Diameter of
DMV)7/3 + (Diameter of SB)7/3

 Finet’s formula was created by IVUS
measurements in normal human coronary arteries
as:
(Diameter of PMV) = 0.678 (i.e.,
approximately 2/3) × (Diameter of DMV +
Diameter of SB)

Definition
 A bifurcation lesion is a major epicardial
coronary artery stenosis next to and/or including
the ostium of a significant side branch
 A significant SB is a branch whose severe
narrowing or acute occlusion before or during
intervention can cause considerable ischemia or
a new infarction area that will worsen the clinical
course of a particular patient

 Other important elements to consider that are not
inherent in the bifurcation classifications include:
 Extent of disease on the SB (limited to the ostium
or involving the vessel beyond the ostium)
 Its size (over 2.5mm in reference diameter)
 Bifurcation angle, and
 Disease distribution

 To determine the significance of the SB
 not only the diameter
 Length
 location and
 collateral function of the SB
 but also the symptoms,
 left ventricular function and
 viability of the supplied myocardium should be evaluated

 A bifurcation coronary lesion is a stenosis
involving or adjacent to the origin of an arterial
side branch ≥2mm in diameter
 The stenosis can involve the large branch (main
branch, MB), the smaller branch

Classification
 Various angiographic classifications of CBL have
been proposed
 Because of its simplicity, the easiest to remember
and most prevalently used is the Medina
classification
 This classification is established on the presence
(“1”) or absence (“0”) of significant stenosis (≥
50%) in the proximal main vessel (MV), distal MV
and SB in CBLs, respectively

 The most important distinction is to divide
bifurcation lesions into “true” bifurcations,
where the MB and SB are both significantly
narrowed (>50% diameter stenosis), and
 “Nontrue” bifurcations, which include all the
other lesions involving a bifurcation

 Medina 1,1,1/1,0,1 and 0,1,1 classes are defined
as “true”
 All others are defined as “non-true“ CBL
Kırat T. Fundamentals of percutaneous coronary bifurcation interventions. World J Car

 “True” bifurcation lesions are more complex
and more difficult to treat with poorer outcomes
than “non-true“ types
 However, in true bifurcation lesions, Medina 1,1,1
and 0,1,1 lesions were found to have a higher
risk of cardiac death, myocardial infarction (MI),
and more SB occlusion than Medina 1,0,1 lesions

Limitations of Medina
classification
 Finally, the Medina classification does not consider
other important information that may direct treatment
strategies, such as:
 Lesion size and length,
 Calcification and bifurcation angles
 Therefore, additional modalities such as multislice
computed tomography (MSCT), intravascular
ultrasound (IVUS), optical coherence tomography
(OCT) and fractional flow reserve (FFR) or other
functional tests may be necessary to clarify the true
classification of a bifurcation lesion and to determine
the treatment strategy

-RVD: Reference vessel diameter

Percutaneous Coronary
Intervention (PCI) Techniques

 The objective of bifurcation PCI is to end the
procedure with both branches open and an
optimal result in the MB

 However, bifurcations vary not only in
anatomy (plaque burden, location of plaque,
angle between branches, diameterof branches,
bifurcation site) but also in the dynamic changes
in anatomy during treatment (plaque shift, carina
shift, dissection)
 As a result, no two bifurcations are identical
and there is no single strategy that can be
applied to every bifurcation

 Thus, the more important issue in bifurcation PCI
is selecting the most appropriate strategy for
an individual bifurcation and optimizing the
performance of this technique

 An individualized approach to treating a
bifurcation is dictated by the SB through
evaluating the following factors:
Factors impacting bifurcation procedure decision
Importance of SB for that patient and for that specific
anatomy
Distribution of disease
Size and territory of distribution
Extent of SB disease
Bifurcation angle
Presence of concomitant distal disease in the SB

Approach for bifurcation
stenting

Importance of SB for that patient
and for that specific anatomy
 The territory of viable myocardium supplied by
the SB and risk of SB occlusion is usually the
most important factor when evaluating the
bifurcation approach

Distribution of disease
 An important distinction is whether the disease at
the bifurcation only involves one branch of the
bifurcation or if it extends into both branches

Size and territory of
distribution
 The size of the branch is not considered in
isolation but in combination with the severity and
length of disease
 In general, SBs that are <2.5mm will not be
stented unless they are long with a somewhat
large territory of distribution or the branch is in
danger of occlusion

Extent of SB disease
 The severity and length of disease in the SB
are probably the most common reasons for
performing double stenting rather than provisional
SB stenting
 Focal ostial SB disease should be treated with a
provisional approach

 However, if the:
 SB is large (≥2.5mm),
 Supplies a relatively large territory of
myocardium, and
 Significant disease that extends 10 mm to 20mm
or more from the ostium
 Favors a double stenting technique from the
outset

Bifurcation angle
 The bifurcation angle is the angle between the MB and SB distal to
the bifurcation
 The bifurcation angle has an influence on the accessibility of the SB
and may frequently be a reason for initially stenting the SB
 A wide angle may make initial wiring of the SB difficult and may also
impede recrossing into the SB with a wire, balloon, or stent after MB
stenting
 However, the decision to electively implant a stent on the SB should
be made only after wire insertion, which may favorably modify this
angle
 An acute bifurcation angle is a predictor of SB occlusion during MB
stenting, that is, the more acute the angle, the higher the risk of
plaque shift, compromise of the ostium, and SB occlusion

Presence of concomitant distal
disease in the SB
 If the ostium is nondiseased but there is distal
disease close to it that can be covered by a long
stent from the MB, prefer double stenting
 However, if the distal disease cannot be treated
with the MB stent and requires a second stent
to be implanted distally, prefer implanting the
distal stent first if possible and then treating the
bifurcation
 This approach avoids difficulty later in passing a
stent through stent struts at the bifurcation

 Many stenting techniques have been developed
and published.
 For simplicity, these techniques were classified by
the European Bifurcation Club (EBC) as “MADS”
in 2008
 However, some techniques have been
abandoned due to adverse outcomes or lack of
effectivity
 Therefore, an updated new classification called
“MADS-2” was created by the EBC in 2020

 Although MADS-2 involves many stenting
techniques, the most widely used major
bifurcation stenting techniques recommended by
the EBC are as follows:
 One-stent techniques: The provisional stenting
technique (PST) and inverted provisional stenting
technique; and
 Two-stent techniques (Elective, or bail-out in
PST):
 T/T and protrusion (TAP) stenting;
 Culotte/inverted Culotte stenting techniques; and

Braunwald intervention cardiology

Technical Aspects Of
Bifurcation PCI

Vascular access and guiding
catheter selection
 In one-stent techniques, most CBLs can be
treated transradially or transfemorally using a 6
Fr guiding catheter (GC)
 Two-stent techniques can also be performed
using 6 Fr GC except when there are two stents
in the GC at the same time, such as mini-crush, V
or simultaneous kissing stenting techniques

 Due to the challenging interventional nature of
CBLs, guiding catheters with strong support, such
as:
 Extra back-up guiding catheters for the left coronary
artery and
 AL 0.75, AL1 or AR2 for the right coronary artery
(RCA)) should be preferred

Wiring Both Branches of the
Bifurcation and Jailed Guidewires
 Two wires should be placed in most bifurcations
and the SB wire should be “jailed” in the majority,
following deployment of the stent on the MB
 This approach of wiring both branches during
bifurcation stenting is important in protecting the
SB from closure due to plaque shift, carina shift,
and/or stent struts during MB stenting
 Even SBs with minimal disease may occlude
during MB stenting

 Occlusion of SBs >1mm can be associated with a 14%
incidence of myocardial infarction, and SB (≥2mm)
compromise during a provisional approach can be
associated with a large periprocedural myocardial infarct
 The jailed SB wire not only protects it from closure but also
facilitates rewiring of the SB (if SB postdilatation-stenting
or final kissing inflation is needed or if the side branch
occludes)
 Finally, in the case of SB occlusion, the jailed wire can be
used to reopen the SB by pushing a small balloon
between the stent and the wall of the vessel
 There is no need to remove the jailed wire during high-
pressure stent dilatation in the MB.
Ref: Braunwald intervention cardiology

Difficult SB Access
 Safe guidewire placement in the MB and SB is the
first step to a successful bifurcation PCI procedure
 In some cases of complex bifurcation anatomy with
wide SB takeoff angles (≥90°) and/or severe
disease at the bifurcation, wiring the SB may be
extremely challenging, and if not properly performed,
it could result in dissection of the SB ostium and acute
closure
 An inability to wire the SB may be a reason not to
perform bifurcation PCI or to abort the procedure
because the risk of losing the SB will be too high
considering the size and distribution of the branch
(typically an angulated circumflex artery).

How to solve difficult side branch
access?
 Antegrade wiring
 Pullback wiring technique
 Reverse wire technique
 Venture wire control catheter or SuperCross angled
tip microcatheter
 Rotational atherectomy
 MB predilatation

Antegrade wiring
 Antegrade wiring with a change of guidewire to a
stiffer or hydrophilic polymer-coated wire, making
a single wide bend or double bend shape, with the
support of a microcatheter
 Stiffer wires enhance precision and torque control
and are usually our first option when a workhorse wire
fails
 Hydrophilic or polymer-jacket wires are usually our
last option because although they may shorten and
facilitate SB wiring, they have a greater risk of wire
perforation or subintimal navigation (especially if the
SB has been injured by balloon dilatation).

Pullback wiring technique
 A guidewire with a smooth, large, distal bend or
loop is advanced into the distal MB and pulled
back to the bifurcation; because of the hook-like
bend, the distal tip of the guidewire engages the
SB ostium; gentle counterclockwise rotation
advances the wire in the SB

Reverse wire technique
 A polymer-jacket hydrophilic guidewire with a
round shape (reverse bend) at about 3cm from
the distal tip is advanced distal to the bifurcation;
 The guidewire is pulled back to the bifurcation
and owing to the hairpin bend, the distal tip
engages the SB;
 A gentle counterclockwise rotation advances the
guidewire in the SB; at this stage, the reverse
guidewire is usually exchanged for a conventional
wire using a microcatheter

Venture wire control catheter
 or SuperCross angled tip
microcatheter
 Enables the guidewire to be
directed toward the SB after active
or passive deflection of the catheter
tip
 The SuperCross catheter tip
changes from a straight tip to its
preformed curve (45, 90, or 120,
depending on which catheter is
selected)
 Venture catheter is actively
deflected to the required angulation;
once the catheter is adequately
oriented to the SB ostium, the
guidewire can be easily advanced.

Rotational atherectomy
 Rotational atherectomy on the MB with the intent
to remove the plaque that prevents entry toward
the SB and facilitate SB wiring

MB predilatation
 MB predilatation with the rationale that the plaque
modification and a favorable plaque shift will
facilitate access toward the SB
 This is usually a last resort, as it may result in
occlusion of the SB

Predilation of the MV and the
SB
 Optimal preparation of the MV is necessary before
stenting
 Therefore, the operator can decide to predilate the
MV and/or perform any debulking procedure
according to the MV lesion properties
 Routine predilation of the SB has been a
controversial issue in the PST
 Predilation aims to prevent SB closure after MV
stenting; however, it can cause dissection that may
prevent guidewire advancement during wire exchange
or may require an extra stent in the SB

 Consequently, it seems that routine predilation
of the SB cannot be recommended currently
Conditions that favor SB predilation:
Severe ostial SB narrowing
Extensive SB calcification
Difficult SB access or decreased flow after MB predilation and/or
debulking

Scenario 1: The SB is not suitable (too
small) for stenting or clinically irrelevant
AND has ostial or diffuse disease
 In these bifurcations, the Keep It Open strategy is
utilized, which is performed as follows:
 Wire both branches
 Dilate the MB if needed but not the SB
 Stent the MB and leave the wire in the SB
 Perform postdilatation of the MB with a jailed wire in the SB
 Do not rewire the SB or postdilate the SB
 This “jailed wire” strategy allows protection of an SB that may
not require treatment but where the need to maintain patency
is important

Scenario 2
 The SB is suitable for stenting AND it has
minimal disease or disease at the ostium only:
 In these bifurcations, the Provisional strategy is
utilized
 The provisional approach is performed as
follows:

1. Wire both branches
2. Predilate the MB and the SB as required; many SBs
without significant disease or calcification do not require
predilatation
3. Stent the MB and perform a proximal optimization
technique (POT), leaving the SB wire in place
4. If the angiographic results in the MB and SB are
satisfactory, the procedure is complete and the SB wire
jailed behind the MB stent struts can be gently removed

Proximal Optimization Technique
(POT)
 To prevent carina shift, the MB stent diameter should be
selected according to the diameter of the distal MB
 Inflation of a short, bigger balloon just proximal to the carina
corrects the underdeployment of the proximal part of the MB
stent
 As a result, the original anatomical configuration of the
bifurcation is restored in compliance with the Murray’s and
Finet’s law
 The POT also changes the orientation of the SB ostium and
the projection of struts in the SB ostium, thus facilitating wire
recrossing into the most distal strut, balloon crossing, and if
necessary, a stent in the SB
 The POT is especially useful in bifurcation lesions with a large

5. Rewire the SB and then remove the jailed wire.
Recrossing through the distal strut (“carina
strut”)
6. Perform SB balloon dilatation and FKBI with
moderate pressure (8atm) in the SB, until the
balloon is fully expanded. FKBI is mandatory if
the SB is dilated through the MB stent struts to
correct MB stent distortion and expansion

Kissing balloon inflation
technique
 After exchanging the wires, a non-
compliant balloon sized to the SB
diameter is inserted into the SB, and
another non-compliant balloon sized to the
DMV diameter is inserted into the MV
 The balloons should be sufficiently short to
prevent inflation outside the MV stent and
disease-free regions in the SB
 Moreover, minimal balloon overlap is
recommended to keep elliptical stent
deformation in the PMV to a minimum

 First, the SB balloon is inflated at a high
pressure to open the struts and eliminate the
stenosis; and after deflation, the MV balloon is
inflated to a high pressure
 Subsequently, to maintain the carina in its central
position, simultaneous inflation and deflation
of both balloons is conducted using moderate
pressures (at approximately 8-10 atm) as high
pressures cause more oval distortion in the PMV
segment of the stent

7. If the result remains unsatisfactory:
 Suboptimal result
 FFR <0.75
 Plaque or carina shift with >75% residual stenosis
or
 TIMI <3; in an SB ≥2.5mm) or
 SB balloon dilatation is complicated by a flow-
limiting SB dissection, perform SB stenting.

Newer side branch protection
techniques
 To prevent side branch occlusion during the PST,
various novel techniques have been developed
recently:
 The pre-kissing technique
 Jailed balloon
 Jailed semi-inflated balloon and
 Modified jailed balloon techniques

 The pre-kissing technique involves the
simultaneous dilation of two undersized balloons
(one in the MV and the other in the SB) whose
proximal parts are aligned in the proximal MV
before MV stenting
 The aim of this technique is to sustain the central
position of the carina while moving the
atherosclerotic plaques away

 The jailed balloon technique (JBT) and the
jailed semi-inflated balloon technique (JSBT)
involve implanting an MV stent while a semi-
compliant balloon is in the SB protruding to the
MV
 The proximal marker of the SB balloon is
positioned to align or 1-2 mm proximal to the
marker of the MV stent
 The SB balloon is uninflated (JBT) or inflated to
low or moderate pressure (< 3 to 7 atm) (JSBT)
during MV stent balloon inflation at nominal
pressure

 After MV stent implantation, if the SB flow is not
compromised (i.e., TIMI-3 flow), the uninflated SB
balloon is inflated at low (< 3 atm) pressure in the
JBT
 If less than TIMI-3 flow in the SB is observed, the
SB balloon is inflated at nominal pressure
 After the balloons are removed, the proximal
optimization technique (POT) is performed in the
PMV

 In the modified jailed balloon technique (M-
JBT), the MV stent is positioned across the SB,
and a balloon is placed in the SB with its proximal
end touching the MB stent
 Both the MV stent and SB balloon are inflated at
the same nominal pressure (e.g., 12 atm)
simultaneously
 After deflation and removal of the balloons, the
POT is performed in the PMV

Technical Tips for Provisional
Approach
 Always wire both branches.
 Predilate the SB only if there is severe disease and/or
the patient is at risk of occlusion after MB stenting.
 The MB stent is selected according to the distal MB
diameter
 The SB wire should be jailed behind the MB stent
 Use the POT to optimize proximal MB stent
deployment and facilitate wire recrossing.

 Recross the MB through the distal strut.
 Do not remove the jailed wire until recrossing or MB
stent optimization has been performed.
 FKBI is not mandatory but probably advantageous in
true bifurcations with significant residual SB stenosis
(>70%) and/or an FFR <0.75
 High pressure proximal stent inflation using a short,
noncompliant balloon should be considered for
correction of possible proximal stent distortion after
FKBI

Crossover to Double Stenting
from a Provisional Approach
 If the SB result remains unsatisfactory after MB
stenting and balloon dilatation of the SB:
 SB stenting should be performed
 SB stenting can be performed with the TAP,
reverse crush, or culotte techniques, followed by
kissing balloon inflation
>75% residual stenosis
Dissection
TIMI flow grade <3 or
FFR <0.75 in an SB ≥2.5mm

T-Technique
 This technique is the one most frequently utilized to shift
from provisional stenting to stenting the SB
 The stent is positioned at the ostium of the SB in an
attempt to minimize any possible gap
 The T technique is best suited when the angle between
the MB and the SB is close to 90° because in narrow
angles it is impossible to fully cover the ostium without
protruding into the MB.
 Thus TAP has replaced this technique in case of narrow
angle
 If the side stent is deployed into the main branch, then this
may be called a “mini-crush or a modified-T stent

T-Stenting and Small Protrusion
(TAP)
 The TAP technique is a modification of the T-
stenting technique and is based on an intentional
minimal protrusion of the SB stent within the MB
 TAP has replaced this
technique in case of
narrow angle

Reverse Crush
 This technique should be used as a crossover
approach with the intent to minimize any possible
stent gap between the MB and SB stents
 In conditions where the angle between the MB
and the SB is acute (usually less than 60°)
 In this situation, the TAP technique may result in
excessive protrusion when attempting to fully
cover the ostium of the SB

Provisional Culotte
 The provisional culotte technique can be
proposed as a provisional SB stenting strategy in
Y-shaped angulated bifurcation lesions without
a large discrepancy in size between the MB and
SB
 Both the reverse crush and culotte require a
second recrossing of stent struts; as a result, they
have been superseded by the TAP when the
bifurcation angle is unfavorable

 The mini-crush technique is a version of the crush
technique in which the crushed part of the SB
stent is 1-2 mm instead of 3-4 mm
 The main advantage of the crush and mini-crush
techniques is that instant patency of both
branches is secured
 However, the main disadvantage of these
techniques is that a 7 Fr guiding catheter is
required because two stents are positioned in the
coronary arteries at the same time

Nano-crush technique
 In the nano-crush technique, the SB stent is
positioned uninflated in the SB, and a non-
compliant MV balloon is positioned across the
carina and then inflated at a nominal pressure
 While the MV balloon is inflated, the SB stent is
pulled back until a small part protrudes into the
MV and is deployed
 The other steps are similar to the DK-crush
stenting technique described before

V-Stenting
 The main application of the V stenting technique
is Medina 0,1,1 Lesions where the PMV is free of
disease and the carinal angle is < 90°

Selection of the double stenting
technique
 Important anatomical factors that need to be
considered include the following:
 Diameter of the two branches
 Bifurcation angle
 Extent of disease in the MB proximal to the carina
 Severity of the ostial SB stenosis
 Presence of dissection in the MB and SB after
predilatation
 Complex bifurcations involving large territories or
emergencies

1. Diameter of the two branches
 If similar, use the culotte or minicrush techniques,
but if there is a large discrepancy between the
proximal MB and SB, the minicrush is preferred

2. Bifurcation angle
 T-stenting and culotte are preferred when the angle is >70°
because the crush technique is associated with a high risk of
stent malapposition in the SB
 Culotte or crush are preferred with angles <70° and T-stenting
should be avoided because it does not provide complete
coverage of the SB ostium

3. Extent of disease in the MB proximal
to the carina
 If minimal, V-stenting may be preferred,
especially in large proximal SBs.
4. Severity of the ostial SB stenosis (does it
require aggressive predilatation?)

5. Presence of dissection in the
MB and SB after predilatation
 If a dissection is present in both branches of the
bifurcation, prefer the minicrush because it
ensures immediate patency of both branches as
compared to the culotte, where recrossing stent
struts into a dissected branch may be challenging
and result in vessel closure.

6. Complex bifurcations involving
large territories or emergencies
 In situations where it is crucial to maintain optimal
patency of both branches, recommends the V-
stenting or minicrush techniques.

 Since coronary angiography is two-dimensional
lumenography, it has some limitations in evaluating lesion
characteristics and post-intervention results
 The intravascular imaging techniques IVUS and OCT
provide accurate tomographic images and essential
information that guides planning and optimizing PCI
treatment
 OCT provides much higher resolution images of the
luminal surface, calcifications, wire positions and SB
ostium than IVU
 On the other hand, IVUS has been used more, needs no
extra contrast or vessel flushing and is better in evaluating
the plaque burden

DRUG–COATED BALLOONS IN
CBLs
 Drug–coated balloons (DCBs) are a new technology
intended for the prevention of restenosis as an
alternative option to DESs
 The use of DCBs in CBL is attractive due to the high
rate of restenosis after CBL intervention
 Observational studies using a DES in the MB and a
DCB in the SB showed good SB results
 Consequently, there still is insufficient conclusive data
on the use of DCBs in de novo CBLs

 4 DBSs were studied in randomized trials:
 BiOSS Expert
 BiOSS LIM (Balton, Warsaw, Poland)
 Tryton stent (Tryton Medical, Durham, North
Carolina) and the
 Axxess bifurcation stent (Biosensors International,
Singapore).

BiOSS Stent
 The BiOSS Expert is a paclitaxel-eluting balloon-
expandable dedicated bifurcation stent that is
implanted in the MV and has an open side to the
ostium of the SB
 The BiOSS LIM is a sirolimus-eluting
balloonexpandable dedicated stent

Tryton stent
 Balloon expandable bare metal stent
 Technically, it has 3 zones.
 Zone 1: SB zone, which provides
superior scaffolding within the SB,
securing it acting like any workhorse
stent.
 Zone 2: It is the Transition zone, which
provides radial strength and complete
coverage to the SB and ostium
regardless of bifurcation angle and
geometry
 Zone 3: Main Branch zone, which
because of minimal metal to artery ratio
(M:A) allows seamless integration with
SB stent. If required, a DES can be
placed in this zone

Axxess Stent
 The Axxess stent is a self-expandable biolimus-
eluting dedicated stent that is designed for EDS
 It is implanted in the proximal MV with its distal
end aligned to the carina, allowing easy access to
both the distal MV and the SB

 The use of bioresorbable scaffolds (BRS) for thetreatment
of coronary artery disease is potentially advantageous by
virtue of complete bioabsorption of struts, which may result
in the recovery of vasomotorfunction, preserved possibility
for positive remodelling, and a potential reduction of very
late clinicaladverse events because of the absence of a
residualpermanent foreign body
 These potential advantages may be even more
pronounced in the settingof bifurcation lesions, which
are associated witha greater occurrence of adverse
events compared with“simple”lesions
 However, clinical experience with this novel technology for
bifurcation lesions islimited, and there is currently no
consensus or recom-mendation with regard to the
optimal technicalapproach

References
 Braunwald intervention cardiology
 Grossmann intervention cardiology
 Kern intervention cardiology
 Topol intervention cardiology
 Kırat T. Fundamentals of percutaneous coronary
bifurcation interventions. World J Cardiol. 2022

Coronary Bifurcation Interventions Guide

Coronary Bifurcation Interventions Guide

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