IVUS analysis of complex techniques (Crush, culotte) IVUS analysis of complex
techniques (Crush, culotte)
Andrejs ErglisLatvian Centre of Cardiology
Pauls Stradins Clinical University HospitalRiga, LATVIA
DisclosuresDisclosures
• Consultant agreement with J&J Cordis• Consultant agreement with Boston
Scientific Corp
IntroductionIntroduction
• IVUS has become an integral part of all interventional studies. Fundamental IVUS parameters characterizing the success and failure of different stenting techniques are:– % neointimal volume obstruction – acute and late malapposition– edge effects
• PCI of bifurcation lesions is complex and challenging. Despite the advance of DES, restenosis at the side branch (SB) ostium continues to be a problem. Still bifurcation lesions have not been studied with IVUS extensively.
IVUS in bifurcations lesionsIVUS in bifurcations lesions
• Pre-intervention:– Involvement of the SB in bifurcation lesion? → diseased?
stenotic? → stenting technique• Postintervention:
– Has SB been compromised (after provisional stenting)?– Is there adequate stent expansion (after stenting both
branches)?• Follow-up:
– Development of neointimal hyperplasia?– Late malapposition, edge effects?
• IVUS can not adequately assess the SB from the main vessel (MV); therefore it is necessary to image the SBdirectly
IVUS and Optical CoherenceTomography
IVUS and Optical CoherenceTomography
PurposePurpose
• There is little data on IVUS findings in both branches after bifurcation lesion intervention regardless of the approach
• Our goal was to acquire and analyze the IVUS images in both branches of bifurcation lesions after different stenting strategies at 8-month follow-up (Nordic Bifurcation Study)
The Nordic Bifurcation Study The Nordic Bifurcation Study
• It was a prospective, multicenter, randomized trial that compared outcomes between 2 different interventional strategies with the sirolimus-eluting stent for the treatment of bifurcation lesions:– Stenting the main vessel with optional stenting of the side branch
(provisional)– Stenting both the main vessel and side branch (routine)
• At 8-month follow-up IVUS substudy was introduced in two centers (Stradins Hospital in Riga, Latvia and SkejbyHospital in Aarhus, Denmark)
MethodsMethods
• IVUS assessment of main vessel or both branches was performed at the time of follow-up angiogram in 115 patients:– 68 patients in Riga and 53 patients in Aarhus
• All IVUS recordings were made with an automated pullback speed of 0.5 mm/s, aiming to start at least 10mm distal and to end at least 10 mm proximal to the stent
• IVUS analysis performed with computer-based quantitative analysis system (QCU–CMS version 4.14 MEDIS Medical Imaging Systems Inc, Leiden, Netherlands)
• IVUS analysis included:– Segment identification– Qualitative analysis– Quantitative (volumetric) analysis
In-stent segmentsIn-stent segments
SB
MB
1
5 4 2
IVUS analysisincluded 5 segments:
1: SB distal stent
2: MB distal stent
3: MB “bifurcation”
4: MB multiple layersof stent
5: MB proximal stent
3
Pitfalls for IVUS analysisPitfalls for IVUS analysis
Stent = 23 mm
Bifurcation segment analysis:
True or phantom results?
The challange for software and/or interpretation?
Volumetric analysis – to be or not to be?
Bifurcation segment = 2 mm
“Crush” technique“Crush” techniqueAngiography:
75% stenosis of RPD/RPL bifurcation
Procedure:1. RPD stenting:
Cypher 2.5x13mm @ 15 atm
2. RPL stenting: Cypher 3.0x23 mm @ 17atm
3. Kissing balloon postdilatation:
• RPD: Maverick 2.5x12mm @ 8atm
• RPL: Larus 3.5x20mm @ 8atm
“Crush” technique“Crush” technique
Final result 8 mo follow-up
Restenosis in side branch
“Crush” technique“Crush” technique
RPLRPL
RPDRPD
4455
Proximal Stent Distal Stent
Cru
sh z
one
Bifu
rcat
ion
Minimum lumen area:MB Distal = 7.30 mm2
MB Bifurcation = 7.34 mm2
MB Crush = 3.47 mm2
MB Proximal = 6.64 mm2
SB MLA = 3.11mm2
33 22 11
22334455** **
11
RPDRPD
RPLRPL
**** ****
Side branch
Proximal MB Crush MB Bifurcation MB Distal MB
Multiple layers of stent strutsMultiple layers of stent struts
Stent = 23 mm
MLS area = 4.5 mm
Crush area (↑) with eccentric intimal hyperplasia (↑ ↑) next to or opposite to multiple layers of stent metal
“Culotte” technique“Culotte” techniqueAngiography:
75% stenosis of LAD/diagonal bifurcation
Procedure:1. Pre-dilatation of LAD:
Maverick 3.0x12 mm @10atm
2. LAD stenting: Cypher 3.5x23 mm @ 16atm
3. Opening struts to diagonal: Maverick 2.5x12mm @ 16atm
4. Diagonal stenting: Cypher 2.75x18mm @ 16 atm
5. Postdilatation of LAD: Aqua 4.0x10 mm @ 10atm
6. Kissing balloon postdilatation:
• LAD: Asahi 3.5x20mm @ 8atm
• D1: Asahi 2.75x18mm @ 8atm
Preintervention
“Culotte” technique“Culotte” technique
Final result 8 months follow-up
“Culotte” technique“Culotte” technique
D1D1
LADLADProximal Stent
Distal Stent
Cullote zone
Bifu
rcat
ion
Major concern:
The MLD and MLA of both branches atthe bifurcationpoint
Minimum lumen area:
Distal Stent = 6.54mm2
Bifurcation = 6.00mm2
Cullote = 6.80mm2
Proximal = 9.97mm2
ResultsResults
• Data from Riga centre are summarized for 35 patients after complex stenting technique:– 23 Crush – 2 Culotte– 12 T-stent
• IVUS was performed in both branches in 30 patients and hyst themain branch in 5 patients
• Overall, MB minimum lumen area (MLA) was larger than the SB: 5.5±1.4 mm2 vs. 4.2 ±1.1 mm2
• In MB, MLA was found in:– Distal stent segment in 15 patients (43%)– “Bifurcation” segment in 11 patients (31%)
2 stents vs 1 stent2 stents vs 1 stent
0.9
0.6
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Main Branch
2 stent 1 stent
5.5 5.4
0
1
2
3
4
5
6
Main Branch
2 stents 1 stent
%NIV = Neointimal Volume x 100 / Stent Volume
P=0.720
P=0.734
Results of 35 patients after complex stentingand 27 after one stent strategy
5.7 5.5
0
1
2
3
4
5
6
Main Branch
2 stents 1 stent
P=0.504
Minimum Lumen Area (mm2)
Minimum Stent Area (mm2)
Minimum Lumen and Stent Area(2 stents)
Minimum Lumen and Stent Area(2 stents)
7.58.1
6
4.2
7.88.3
6.1
4.2
0
1
2
3
4
5
6
7
8
9
Proximal MainBranch Stent
Multiple layer MBstent
Distal Main BranchStent
Distal Side BranchStent
Lumen Stent
Results of 35 patients after complex stenting:
21 – Crush technique
2 – Culotte technique
12 – T-stent technique
Minimum lumen area p ANOVA < 0.001
Minimum stent area p ANOVA < 0.001
Minimum Lumen & Stent Area (mm2)
Percent neointimal volume obstruction(2 stents)
Percent neointimal volume obstruction(2 stents)
1.5
2.2
0.4 0.5
0
0.5
1
1.5
2
2.5
Proximal MainBranch Stent
Multiple layer MBstent
Distal Main BranchStent
Distal Side BranchStent
%NIV = Neointimal Volume x 100 / Stent VolumeResults of 35 patients after complex stenting:
21 – Crush technique
2 – Culotte technique
12 – T-stent technique
P=0.778 P=0.312
Crush/Cullote vs T-stentCrush/Cullote vs T-stent
2.1
0.50.7
0.30.1 0.2
0
0.5
1
1.5
2
2.5
Proximal Main Branch Stent Distal Main Branch Stent Distal Side Branch Stent
Crush/Culotte T-stent
7.8
6.3
4.3
6.8
5.6
4
0
1
2
3
4
5
6
7
8
9
Proximal Main Branch Stent Distal Main Branch Stent Distal Side Branch Stent
Crush/Culotte T-stent
Results of 35 patients after complex stenting:
21 – Crush technique; 2 – Cullote technique;
12 – T-stent technique
%NIV
P=NS
P=NS
8
6.4
4.3
7.3
5.6
4.1
0
1
2
3
4
5
6
7
8
9
Proximal Main Branch Stent Distal Main Branch Stent Distal Side Branch Stent
Crush/Culotte T-stent
P=NS
Minimum Lumen Area (mm2)
Minimum Stent Area (mm2)
ConclusionsConclusions
• First results from Nordic Bifurcation Studydemonstrates a trend toward increased neointimal hyperplasia in the main branch segment with multiple layers of stent strutsdespite the minimum lumen/stent area at the side branch
• The major limitation of our study is the lack of pre-interventional and post-implantation IVUS images
ConclusionsConclusions
• Serial IVUS studies are needed to completely assess the success and failure of different complex stenting strategies in bifurcation lesions
• Both branches should be examined to exclude a contribution of stent under-expansion to restenosis and to obtain adequate assessment of SB.
• Standards for the IVUS acquisition and measurements in bifurcation lesions must be established
