1. Optimal Stent Expansion and Optimization
Non-Compliant Balloons
Optimal Stent Expansion and Optimization

2. Non-compliant balloons
Despite advances in stent technology and implantation techniques, both acute and long‐term complications still occur
Stent underexpansion has been defined as a major risk factor for both of these adverse events. Thus, stent optimization after deployment is crucial
Post Dilatation has been recommended to overcome these complications and provide optimal stent expansion in PCI
Tasal, et al Journal of Interventional Cardiology; Vol 26, No. 4, 2013

3. Pre-dilatation for challenging lesions
Pre-dilatation may be appropriate in treatment of complex lesions
Calcified Lesions
CTO’s, Angulated Lesions
B2/C Lesions
Bifurcations
Lesions with significant calcification may be difficult to expand
Pre-dilatation minimizes the risk of inadequate stent expansion
Kissing balloon technique (KBT) is an important part of stent optimization, used in bifurcation lesions1
EBC recommends the use of NC Balloons to prevent over-dilatation during kissing inflations2
Initial angioplasty with small diameter balloon, followed by larger sized balloon catheters or stents
Pre-dilatation may limit stent length and reduce complications3
1 Sgueglia , et.al. JACC CI 2012
2. Hildick-Smith et al. EuroIntervention 2010;6:34-38
3. Kandzari, CCI 2010

4. Post Dilatation for Optimal Expansion
Post-Dilatation is important for optimization of stent apposition to the vessel wall1
DES studies have shown that stent under expansion is common in initial stent deployment and a strong predictor of stent thrombosis and target vessel revascularization (TVR)2
“Of 256 patients with IVUS studies [...], only 29% achieved optimum stent deployment with the stent delivery system.”4
“Inadequate stent expansion results in abnormal shear stress that might be associated with stent thrombosis.”5
Full stent apposition is key to achieving positive, long-term outcomes 2,3
1 Parikh, M. TCT Brodie. J Interv Cardiol Fitzgerald & Leon. Netherlands Heart Journal, Volume 14, Number 9, September Brodie et al, CCI Fuji et al, Journal of the American College of Cardiology 2005

5. Stent Malapposition – Contributing Factors
You cannot determine if a stent is well apposed based on angiography alone.
Stent malapposition contributing factors include:
Low pressure stent deployment
Long lesions requiring multiple stents
Lesions with heavy calcification
Treatment of diffuse in-stent restenosis
Lesions with severe stenosis
Bifurcation lesions with side-branch stenting
Romagnoli JACC CI 2008

6. Stent Deployment Optimization
High pressure NC Balloons are used to ensure a uniform distribution of wall stress, maximal stent expansion and stent strut apposition.
Stent Optimization Goals3:
NC Balloon Attributes
Complete stent apposition to the vessel wall
Adequate stent expansion
Full lesion coverage without edge dissection
High pressure, non-compliant balloons should be used post stent-deployment1
The non-compliant balloon used is shorter and usually one-quarter size larger2
Stent optimization aims at preventing incomplete stent expansion and stent malapposition to the vessel wall after the intervention.
Post-dilatation with a non-compliant (NC) balloon as opposed to a stent-mounted semicompliant balloon theoretically assures a more uniform distribution of wall stress and stent expansion and axial stent symmetry indices improve
DES – NC balloons help ensure complete apposition
Bifurcations – NC balloons are recommended for final KBT and post dilatation (POT)
Stent optimizaiton means ensuring good apposition of stent struts to the vessel wall, such that the stent struts are not surrounded by lumen, adequate stent expansion to obtain MSA at least > 6.5 mm2 for
BMSs and > 5.0 mm2 for DESs or MSA > 90% of the distal reference lumen CSA, and lack of major dissections, intramural hematomas, and geographic misses. (Yoon & Hur. Korean J Intern Med 2012)
Risk of “dog bone”/ edge effect with SC balloon at high pressure
NC balloon at high pressure
Protruding
Apposed to the intima but not embedded
Malapposed
No contact to the intima
1 Romagnoli et al, J.Am Coll Cardio Intv Brodie. J Interven Cardiol Yoon & Hur. Korean J Intern Med 2012
1Di Mario C, et al, 2008

7. Post Dilatation Considerations
Increased procedure cost and operational inefficiencies1,2
Limits cath lab capacity and through out. Use up more resources during longer procedure time
Edge Dissection/ Perforation1,2
A tear created within the tissue wall. Requires another stent and drug therapy or CABG for more severe cases
Longitudinal Stent Deformation3
Balloon may get trapped. If it can not be removed may require surgery.
Increased intimal damage4
Dilating the vessel more often creates more vessel trauma.
Distal Embolization5
a distal filling defect with an abrupt ‘cut-off’ in one of the peripheral coronary branches of the infarct related artery, distal to the angioplasty site.
Frobert PLoS ONE ,2 J. Ormiston, CRT2013)3 sciencedirect.com Intimal hyperplasia4 J. P. S. Henriques, et al European Heart Journal (2002)5

8. NC Balloon Characteristics
NC Balloons offer the best opportunity for good stent/vessel apposition due to high pressure & low compliance1
Recommended in the stent IFUs
Important NC Balloon characteristics include2:
Strength/from Durable Material
Incorporation of these important balloon characteristics may help to reduce the identified risks sometimes associated with Post-Dilatation
High RBP (up to 20atm)
Pushable and Trackable
Low Radial Growth Rate
Low Longitudinal Growth Rate
1 Brodie. J Interven Cardiol. 2006, 2 Stone, TCT2013

9. Clinical Outcomes - Post-Dilatation after Stent
In this study, Post-dilatation was performed safely in patients with AMI
The data show that it may reduce risk of TVR and ST without increasing adverse cardiovascular events or mortality
P = 0.49
P = 0.04
P = 0.04
P = 0.10
Events at 6 month follow up
Tasal, et al Journal of Interventional Cardiology; Vol 26, No. 4, 2013

10. Careful vessel preparation can influence TLF
The RESOLUTE Japan Trial was conducted using careful lesion preparation and extensive imaging.
RESOLUTE Japan TLF to 3 Yrs 4 8 12 16 20 24 28 32 36 2 6 10
Target Lesion Failure (%)
4.0%
RESOLUTE Japan
Lesion Prep/Imaging
IVUS Use (%) 99
Pre-Dilation Pressure
Range (min, max)
6.00, 24.00
Post-Dilatation (%) 78
The Japan Clinical Trial was conducted with extensive lesion preparation and extensive imaging, similar to what is recommended in the ABSORB Trials
Months
100 96 95 94 93 91
Number
at risk
The 3-year TLF rate from RESOLUTE Japan was 4.0%
No TLF creep was seen in the RESOLUTE Japan trial

11. Discussion
Dilatation with a noncompliant balloon (NC) after stent deployment at 6 months has shown:
to provide optimal stent expansion,
reduced target vessel revascularization (TVR),
provide better angiographic results and
Improve clinical outcomes in elective PCI