management of bifurcation lesions

1. Bifurcation Lesions and
Intervention
Dr. Yogesh Shilimkar
SR, Dept of Cardiology,
MCH Kottayam
1

2. Definition:
• The European Bifurcation Club (EBC) defines BIF as:
• “a coronary artery narrowing occurring adjacent to, and/or
involving, the origin of a significant side branch”.
• A significant side branch is defined by this group as a
• “branch that you do not want to lose in the global context of a
particular patient (symptoms, location of ischemia, branch
responsible for symptoms or ischemia, viability, collateralizing
vessel, left ventricular function…).”
2

3. • Represent approximately 20% of coronary interventions.
• “True bifurcations”: the main branch (MB) and the side branch
(SB) are both significantly narrowed (>50% diameter stenosis).
(i.e., Medina 1,1,1; 1,0,1; or 0,1,1)
• “Nontrue” bifurcations: include all the other lesions involving a
bifurcation.
3

4. What defines the main branch and the side
branch?
• Louvard et al. propose two approaches.
• “Nosologic approach,” where the left anterior descending (LAD),
Circumflex, and posterior descending artery, regardless of their
size, are always considered the main branch.
• The second approach is using quantitative coronary
angiography, where the main branch is the largest distal branch
and the side branch is smaller.
4

5. 5

6. ANATOMY AND FUNCTION OF A BIF
• Murray’s law, defines the diameter
relationship between the proximal main
vessel and the 2 distal branches, the
distal main and side branch as:
(D1)3= (D2)3 + (D3)3
• These laws may be simplified and
expressed by Finet’s formula as
follows:
D1 = (D2 + D3) x 0.678
6

7. Areas of low and oscillatory
endothelial shear stress,
which is non-uniform, ->
plaque accumulation.
High uniform
shear stress is
exhibited at
the carinal
level, and
these areas
are not as
likely to
exhibit plaque
formation
7

8. Bifurcation Classifications
8

9. 9

10. • The Medina classification system is based on three number
binary notations.
• Each segment is assigned a value 0 in the absence of
significant stenosis and 1 in the presence of a stenosis >50%.
• A value of 0 or 1 is therefore assigned to each of the three
segments separated in the following order:
• proximal segment (PM),
• main distal segment (DM),
• side branch (SB).
10

11. Medina classification True bifurcations
11

12. Limitations of Medina classification:
• Does not take into account:
1. Length of the disease in the ostium of the side branch
2. Length of the LMCA before the bifurcation
3. Trifurcation
4. Vessel angulation
5. No differentiation is made between a normal segment
and <50% lesion
6. Presence of calcification is not identified
12

13. Classification of bifurcation treatment techniques
• The classification proposed by the EBC was based on two principles:
• the final position of the stent(s) (1 to 3 stents) in the bifurcation and
• the implantation order.
• The position of the first stent in a bifurcation corresponds to a given
strategy.
• There are four strategies designated as MADS (named by R.
Kornowski)
13

14. M strategy begins by a stent in
the proximal Main segment.
Strategy A begins with a stent
in the main vessel Across the
SB.
Strategy D defines a Double
stent implantation whether
simultaneous or not.
S strategy consists of a stent
implantation in the SB first with
protrusion (short or long) or
not.
After implantation of the first
stent(s), further stents can be
implanted using different
techniques.
14

15. RESOLVE score
• To predict the risk of SB occlusion
during PCI of bifurcation lesions.
• RESOLVE scores range from 0 to
43.
15

16. • The RESOLVE score has a good predictive value with the
risk of SB occlusion divided into quartiles.
• Event rates in the derivation cohort across quartiles of
RESOLVE score were:
• 1.0% in quartile I (RESOLVE score: 0 to 2);
• 3.9% in quartile II (RESOLVE score: 3 to 6);
• 3.6% in quartile III (RESOLVE score: 7 to 9); and
• 17.5% in quartile IV (RESOLVE score: ≥10)
16

17. One stent vs Two stent technique
• In a one-stent approach,
• the MB is stented and
• the SB is stented provisionally only if
• clinical symptoms and/or
• angiographic (e.g., < TIMI flow) or adjunctive features (e.g., FFR
<0.80) warrant intervention.
• Whereas, a two-stent approach involves elective
stenting of both the MB and SB.
17

18. Important trials
18

19. 19

20. 20

21. 21

22. • Moreover, results from the Nordic IV and EBC TWO (European Bifurcation
Club 2) trials showed no difference between provisional and 2-stent
techniques with regard to major adverse cardiac events.
• Preferred approach for most bifurcation lesions
• main branch-only stenting with provisional stenting of the side branch
• Exceptions to this rule, where upfront side branch stenting may be
preferable, include
• the presence of a large side branch (≥ 2.75 mm) with a long ostial side branch lesion
(>5 mm) or
• anticipated difficulty in accessing an important side branch after main branch stenting,
• true distal LM bifurcations.
22

23. 23

24. Provisional SB stenting strategy
• It is the currently recommended default strategy for approaching
bifurcation PCI.
• The main postulates of the provisional single-stent strategy are
• optimal MB stenting and
• subsequent SB stenting only in case of
• significant flow impairment and/or
• severe stenosis with haemodynamic relevance for a clinically
important myocardial territory
24

25. Guide Catheter Selection
• A majority of BIF cases can be undertaken through
the radial approach using a 6-F guiding catheter.
• A larger guide (7-F) considered when
• using adjunctive technology such as rotational
atherectomy (>1.75 mm burr size) or
• a strategy that requires simultaneous use of 2 stents or 3
balloons.
25

26. 1.First each distal branch is wired (most
angulated branch wired first).
2. Then main branch stenting done with a
diameter selected according to distal main
diameter.
3, 4. The proximal optimization technique
with a short balloon with a diameter adapted
to proximal main diameter.
5. Guidewire exchange performed.
6. The jailed wire is withdrawn carefully to
avoid abrupt guiding catheter intubation, and
subsequently advanced into the distal main
branch.
7, 8. Kissing balloon inflation is carried out
with 2 short balloons, preferably
noncompliant with a diameter compatible
with both distal branches.
26

27. EuroIntervention2018;13:e1804-e1811
27

28. The rationale for wiring the SB prior to MB stenting
1. Jailed wire serves as a marker for rewiring of SB through the MB stent struts.
2. SB wiring reduces the bifurcation angle, thus setting a more favorable
anatomical position for rewiring and advancement of balloons and stents into
the SB.
3. Jailed wire may improve SB patency after MB stenting.
4. In case of a clinical urgency and after multiple failed attempts at SB rewiring, a
small balloon may be advanced over the jailed wire between the stent and the
vessel wall to facilitate acute SB reopening.
5. Jailed wire may serve as an anchor for deeper intubation of the guiding
catheter, thus increasing the support in case of difficult SB balloon crossing.
28

29. PRE-DILATION
• Pre-dilation of the MB depends on operator preference
on the basis of clinical and anatomical conditions.
• However, optimal MB lesion preparation is
recommended.
• Routine SB dilation is not recommended, except
• in the presence of severe ostial stenosis of the SB,
• a very calcified SB or
• in cases of SB difficult access.
29

30. MB stenting
• Drug-eluting stents are recommended for
bifurcation PCI.
• MB stent diameter - selected according to the
reference diameter of the distal MB.
• The MB stent should extend at least 8-10 mm
proximal to the carina in order to prevent
balloon trauma at the proximal stent edge
during the performance of the proximal
optimisation technique (POT).
30

31. • Choosing a stent whose platform accommodates expansion to
the reference diameter of the proximal MV segment is required
and necessary to avoid stent fracture.
• Selection of a MB stent diameter adapted to the DM always
results in stent malapposition in the PM, with a risk of difficult
guidewire exchange and increased risk of stent thrombosis.
• This can be easily solved by the proximal optimization technique (POT)
technique.
31

32. Proximal Optimization Technique
A)Stent implantation in the MB sized according to the distal reference and
therefore undersized in the proximal MB.
B)Short NC or SC balloon is positioned with the distal marker in front of the
carina and the proximal marker inside the proximal stent edge.
C)Inflation of the balloon for POT.
32

33. • POT should be performed routinely after MB stenting to correct
for stent undersizing in the proximal MB.
• If NC balloons are unavailable, performing POT with a semi-
compliant (SC) balloon may be considered.
• It is not recommended to post-dilate the MB stent distally to the
carina with the balloon sized according to the proximal MB
diameter, as this inflation may aggravate carina shift, contributing
to SB compromise/occlusion.
33

34. • POT is performed with the aim of achieving the:
1. Correction of malapposition in the proximal MB.
2. Facilitation of the SB rewiring by
• modifying the orientation of the SB ostium and
• preventing the guidewire from entering the space between the stent
and the vessel wall.
3. Facilitation of SB ostium scaffolding.
4. Restoration of the circularity of the proximal vessel.
34

35. 35

36. Guidewire Exchange Technique
• Guidewire exchange is normally carried out by pulling back the
MV wire to insert it into the SB through the most distal cell, thus
allowing the projection of struts in the ostial segment of the SB
opposite the carina.
• The jailed wire is subsequently removed under fluoroscopy from
the SB and inserted into the DM segment preferably with a loop
to avoid crossing under a strut (unlikely after POT).
36

37. • Recrossing wire through the strut closest to the carina showed
better scaffolding of the side branch ostium than proximal
recrossing that pushes the struts inward toward the main vessel
lumen.
37

38. Rationale for SB opening and kissing balloon
inflation
• Routine performance of final KBI is not recommended in a single-stent bifurcation
PCI, specifically in the absence of a true bifurcation stenosis.
• SB unsuitable for stenting (<2 mm), with normal flow, no angina, or
electrocardiogram signs does not require intervention.
• However, SB ostium dilation is recommended when:
• inadequate results are achieved,
• antegrade flow is impaired (TIMI flow grade <3),
• severe ostial SB narrowing is present (> 75%) and
• FFR of the SB is <0.80.
38

39. • An NC balloon is recommended for SB dilatation and should be
sized according to the SB reference diameter to reduce the risk
of dissection.
• An SC balloon may be used for SB dilatation keeping in mind
the diameter achieved in the range of inflation pressures.
• KBI is recommended with two NC balloons, sized according to
the SB and distal MB, with a short proximal overlap.
39

40. “Modified KBI approach”
• Proposed by Foin et al.
• To reduce proximal stent deformation, relatively long balloons
are used
• Using asymmetric inflation pressures:
• the SB is first inflated to 12 atm,
• then partly deflated back to 4 atm,
• with subsequent simultaneous inflation of the both balloons at 12 atm.
40

41. After Initial proximal
optimization technique (POT) :
(5, 6) Wire exchange is done by
wiring the side branch (SB)
through the main branch distal
strut.
(7) SB opened using a short
noncompliant balloon.
(8) Re–proximal optimization
done to restore stent distortion
opposite to the SB.
POT-SB dilation-POT
sequence
41

42. EuroIntervention2018;13:e1804-
e1811
42

43. 43

44. SB stenting should be considered
1. When there is significant SB flow impairment (Thrombolysis In
Myocardial Infarction flow grade <3);
2. In the presence of a major SB dissection;
3. When the SB is diseased and large enough to lead to significant residual
ischemia; or
4. When future access toward the SB may be important.
5. Decision for SB intervention can be guided by fractional flow reserve
assessment.
44

45. • A second stent can be deployed using one of the following
strategies:
• T-stenting,
• T-stenting and small protrusion (TAP), or
• Culotte.
• Reverse/internal crush
• T-stenting is preferred for T-shape angulation
• TAP or culotte is preferred for Y-shape angulation to obtain
perfect SB ostium scaffolding.
45

46. Traditional T stent
technique
PROBLEM:
It is associated with high risk of
missing the side branch ostium
46

47. T 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.
• This technique can be described as follows:
• A second stent is advanced in the SB in a way to minimally protrude (1
or 2 mm) into the MB.
• A balloon is advanced in the MB.
• The SB stent is deployed as usual (12 atm or more), and the MB
balloon is simultaneously inflated at 12 atm or more.
• Both balloons are deflated and removed.
47

48. • The advantages of the TAP technique are
• compatibility with 6 Fr guiding catheters,
• full coverage of the side branch ostium and
• facilitation of KBI.
• The main drawback is related to the creation of a “metallic
neocarina” of variable length, depending on the SB angle.
• Therefore try to limit the protrusion of the SB stent inside the MB and
reduce the length of the neocarina.
• When final POT is performed in TAP, precise balloon positioning is
crucial to avoid crushing the metallic neocarina.
48

49. Reverse/internal crush:
49

50. The provisional culotte technique
• The culotte technique can be proposed as a provisional SB
stenting strategy in Y shape angulated bifurcation lesions.
• Technique:
• After MB stenting, a second stent is advanced in the SB protruding into
the MB to overlap with the proximal part of the MB stent and expanded
following removal of MB wire.
• MB is rewired through the stent struts and dilated.
• Finally, kissing balloon inflation is performed.
50

51. TECHNICAL CHALLENGES
51

52. UNABLE TO WIRE SB
• In cases of difficult SB wiring, it is useful to enter the SB by
pulling back an angulated wire already inserted in the MB (“pull-
back technique”).
• New hydrophilic wires with good torque transmission can also
be used (Fielder FC, Fielder XT, Sion, Asahi Intecc, Nagoya,
Japan).
• In the presence of a severe angle between the MB and the SB,
the Venture Catheter with its steerable tip can be helpful.
52

53. • In some cases, the “reverse wire technique”, can be
very valuable.
• Dual-lumen microcatheters can also be useful to
facilitate SB wiring in difficult cases.
• As a last resort, plaque modification through dilation
with an undersized balloon proximal to the carina, or
rotational atherectomy of the MB may help solve the
issue.
53

54. • If SB rewiring is still not possible, a bail
out technique can be performed using a
very small balloon (1.0 to 1.5 mm)
inserted over the jailed wire outside the
stent that is then inflated to reestablish
flow in the SB.
• This allows rewiring using the
conventional approach through the MB
stent and then the provisional SB
stenting can be performed.
54

55. • If recrossing through the strut opposite the SB still
proves impossible, the technique may be converted into
the inverted crush technique.
• A larger balloon is inserted over the “jailed” wire,
crushing the MB stent with a wire protection, and a
second stent is placed in the PM toward the SB,
followed by KBI.
• In very high-risk settings, protection techniques using a
jailed SB balloon may be implemented.
55

56. FAILURE TO ADVANCE BALLOON IN SB
• Failure to advance a balloon to the SB can occur due to
several factors, including
• wire wrap,
• poor support,
• extreme angulation, or
• incorrect SB wire positioning.
• Wire wrap can be identified when the MB wire is seen
retracting back while pushing the SB balloon.
56

57. Advancement into the SB can be facilitated by:
1. Use of lowest-profile balloon available on the shelf (1.2 mm & 1.25 mm);
2. The anchoring balloon technique with inflation of a balloon to nominal
pressure in the distal stented MB, which will improve catheter support
and allow crossing of the balloon into the SB;
3. Re-POT at higher pressure or with a larger balloon to increase strut size
at SB;
4. Rewiring the MB to correct wire wrap, which is sometimes required.
57

58. TWO STENTS AS INTENTION-TO-TREAT
58

59. 59

60. • A 2-stent technique is usually considered in bifurcation lesions
where
• the SB is >2.5 mm with
• >50% stenosis
• extending >5 mm beyond the SB ostium.
• Two-stent techniques
• The Culotte technique
• The Mini-Crush Technique (Side-Branch Stent Crushed by the Main
Branch Stent)
• Step Crush and Double-Kissing Crush
• The V and the Simultaneous Kissing Stent Techniques
• The “Y” and the “Skirt” Techniques
• Flower Petal Stenting
60

61. CULOTTE TECHNIQUE
• This technique is
• suitable for all angles of bifurcations and
• provides near-perfect coverage of the
SB ostium.
• Disadvantages:
• leads to a high concentration of metal
with a double-stent layer at the carina
and in the proximal part of the
bifurcation.
• rewiring both branches through the stent
struts can be difficult and time-
consuming.
61

62. The Mini-Crush Technique
62

63. • Advantage of the crush technique: immediate patency of both
branches is ensured.
• Disadvantage: the performance of the FKBI makes the
procedure more laborious, due to the need to recross multiple
struts with a wire and a balloon.
• The performance of the crush technique requires a 7- or 8-Fr
guiding catheter, and the technique commits the operator to
implant two stents.
63

64. DOUBLE KISSING CRUSH TECHNIQUE
(1) Stenting the SB (with 1 to 2 mm protrusion in the MV).
(2) SB stent balloon crush.
(3) SB wire recrossing.
(4) First kissing balloon inflation.
64

65. (5) Main branch stenting across the SB after SB wire is removed.
(6) Proximal optimization technique.
(7) Second SB wire recrossing through main branch stent & the crushed SB stent.
(8) Second kissing balloon inflation.
65

66. (9) Re–proximal
optimization
technique.
(10) Final result.
66

67. • Contrary to the provisional SB stenting approach where
guidewire recrossing is distal, recrossing the SB in double
kissing crush should be carried out through the most proximal
strut.
• Compared to the classic crush strategy, the double kissing
crush is superior in terms of final KBI success rate and seems
to be superior in terms of repeat intervention rates as shown in
the DK-CRUSH I, II, and III studies.
67

68. • Double kissing crush
• not affected by the angle
• but stent fractures may play a role in the occurrence of
SB ostial restenosis after the crush technique in general.
• There is now a “modified” double kissing crush, which
is a little bit more simple and seems to give similar
results:
• the first kiss after crushing is replaced by balloon dilation
of the SB through the crushed MB stent.
68

69. The Simultaneous Kissing Stent (SKS)
Technique
69

70. Simultaneous Kissing Stent Technique (SKS)
• Advantages:
• Simple
• Maintains wire access to
both branches at all times
• Minimal ischemic time
• Disadvantages:
• Can be difficult to rewire later
• Longer carinas can create
problems later
• Requires larger vessels of
similar size
70

71. Simultaneous V Stenting Technique
71

72. Simultaneous V Stenting Technique
72

73. Proposed approach when implanting two
stents on a bifurcation as intention-to-treat
73

74. 74

75. 75

76. EuroIntervention2018;13:e1804-e1811
76

77. LEFT MAIN BIFURCATION
77

78. Indications for LM treatment
• European Society of Cardiology/European Association for
Cardio-Thoracic Surgery guidelines on myocardial
revascularization give a class 1 indication for percutaneous
coronary intervention (PCI) in patients with significant LM
disease and a low/intermediate SYNTAX score.
• PCI in patients with significant LM disease with a SYNTAX
score ≥33 is given a class III recommendation.
78

79. • If there is angiographic ambiguity, accumulated
evidence to date suggests:
• IVUS-derived minimal lumen area (MLA) >6 mm2 and
• FFR >0.80 are acceptable criteria for deferral of LM
treatment
• (with the limitation that evaluation of a LM stenosis with
FFR may be inaccurate if LAD or CX disease is present).
79

80. Differences between the LM and other bifurcations
• The SB is usually the Cx which most often has a large reference diameter and is
angulated making it difficult to access with guidewires.
• A highly angulated LCx take-off may impact on prognosis after LM stenting.
• The LM is the only bifurcation where the proximal MB originates directly from the
aorta. This increases complexity because of the interaction with the guide
catheter and the potential for guidewires to go behind LM stent struts.
• Longitudinal compression during left main stenting is common and when
untreated is associated with an adverse outcome.
• The proximal reference diameter may reach 6 mm – which is close to the
dilatation limit of many coronary stents.
• Left main trifurcations are encountered in about 10% of LM cases and require
specific treatment strategies.
80

81. • A provisional SB stenting approach is recommended for LM
treatment in most cases.
• Coronary calcification is especially common, and the presence of
calcium means that adjunctive plaque modification may be required
to facilitate optimal stent implantation.
• When plaque modification is felt to be unnecessary, either invasive
imaging or careful predilation with an appropriately large (ideally
non-compliant) balloon is recommended to ensure that subsequent
stent expansion is possible.
81

82. • Initial wiring of the SB is recommended, and a careful single-
stent approach with POT is particularly applicable because of
the changes in vessel calibre proximal and distal to the LM
bifurcation.
• Appropriate POT will reduce malapposition which is common in
the LM and this may also reduce longitudinal shortening.
82

83. DRUG-COATED BALLOON FOR SB?
• Given that the provisional stenting technique is the favored
technique, the potential benefits of DCB in the treatment of
bifurcations are:
• an administration of drug to the vessel wall, especially the SB ostium;
• lack of distortion of the original anatomy of the bifurcation;
• minimization of strut deformation at the carina and
• potential decrease in duration of dual antiplatelet therapy.
• Data from PEPCAD-BIF, BABILION & DEBIUT trials suggest that
DCB in the setting of bifurcations require further evaluation.
83

84. BIORESORBABLE SCAFFOLDS
• The first clinically tested bioresorbable stents (BRSs) (Absorb
BVS, Abbot Vascular) showed
• increased rates of major cardiovascular events,
• driven by a higher device thrombosis rate, as compared with
contemporary second-generation DES.
• Hence, discontinued.
• New generation BRS being evaluated:
• Magmaris magnesium alloy bioresorbable scaffold, for treatment of
complex bifurcation lesions
84

85. DEDICATED BIFURCATION STENTS
• Complete bifurcation Y stents
• BARD, AVE, Cordis
• Side Branch Access Stents
• Deliver over 2 wires
• Taxus Petal, Pathfinder, Aristek, Sidekick
• Dedicated Side Branch Stents
• No provisional SB stent option
• Sideguard (Capella), Tryton
• Self-expanding
• Delivery over 1 wire; limited SB protection
• Devax, Stentys
85

86. TRYTON IDE trial
• Did not meet its primary end point of statistical
noninferiority in patients who underwent stenting of the
MV and SB versus those who underwent stenting of the
MV alone with a provisional strategy to stent the SB if
necessary
86

87. ROLE OF ADJUNCTIVE PROCEDURES
87

88. Intracoronary imaging
• Both IVUS and OCT may provide crucial information in planning and
optimising treatment of a bifurcation.
• Compared to IVUS, OCT provides superior images of the lumen
surface, calcified plaques, predilatation results, stent positions, wire
positions and the SB ostium from both MB and SB pullbacks.
• IVUS allows better characterisation of plaque burden and does not
require vessel flushing or additional contrast during acquisition.
88

89. Main uses of IVUS and OCT
• BEFORE STENT IMPLANTATION
• Assessment of lesions proximal or distal to the SB and ostial stenosis
which affect the likelihood of SB compromise after MB stenting
• Planning of stent length including planning size and length of balloon
for POT
• Assessment of segmental stent diameters based on proximal and distal
reference size estimations.
89

90. • POST INITIAL STENTING
• Rule out residual edge stenosis and dissection
• Evaluate stent expansion and apposition
• Verify wire position in SB recrossing and rule out accidental abluminal
rewiring especially in two-stent techniques.
• AFTER POST-DILATION
• Final scan after KBI to evaluate the SB ostium.
• When an SB stent has been implanted, it is recommended to scan the
stented SB and evaluate stent expansion and apposition.
90

91. 91

92. 2011 ACCF/AHA/SCAI Guideline for Percutaneous
Coronary Intervention
92

93. 2018 ESC/EACTS Guidelines on myocardial
revascularization
93

94. Thank You!
94