Current status of clinical
trials vs. optimal outcome
Ernst Groechenig
Aarau
www.gefaessmedizin.ch
Donnerstag, 19. September 13
Treatment of SFA occlusive diseases
conservative treatment
Angioplasty
Pure Ballon Angioplasty
Drug coated Ballons
Atherectomy
bare metal stents
drug eluting stents
Surgery
Donnerstag, 19. September 13
DCB: Improving Outcomes & Options
Improving Outcomes: notably good results
Improving Options : nothing left behind
Treatment
DEB
Anatomy Applicability
No limitations
Possible Outcomes
Patent Vessel
DEB Benefits
No Metal
Donnerstag, 19. September 13
Restenosis
All options
available
DEB: Improving
options pre- and
post-treatment
If stent, treating
more focal lesions
SFA - Stenting
The bailout stenting concept
• Significant residual stenosis
• Flow limiting dissection
Objective: improve technical success by a mechanical
stabilization of the suboptimal segment
Donnerstag, 19. September 13
SFA Stenting
The extended concept of SFA-stenting
•
indication: all complex SFA lesion (>4 cm)
Objective:
- to improve technical success by a mechanical stabilization
of the suboptimal segment
- To reduce the restenosis rate at long-term
Donnerstag, 19. September 13
FAST Trial
Prospective, randomized, controlled
– PTA vs. Luminexx nitinol stent (Bard)
endpoints = duplex based patency + stentfracture
PTA
Intention to treat
121
123
On treatment
108
136
4.5cm
4.5cm
Occlusions
25%
37%
1Y patency (duplex)
61%
68%
Lesion length
Schillinger et al, N Engl J Med 2006;354:1879-88, Circulation 2007.
Donnerstag, 19. September 13
Stent
NS
RESILIENT Trial
Prospective, randomized, controlled
– PTA vs. triple helix nitinol Lifestent (Edwards - Bard)
Endpoints = Duplex based patency + Stent fractures
PTA alone
Intention to treat
69
137
-
-
6.4cm
7.1cm
38%
80%
-
3%
On treatment
Lesion length
1Y patency (duplex)
1Y fracture rate
Katzen et al, unpublished – presented at ISET 2008
Donnerstag, 19. September 13
Stent
p<.0001
Astron Trial
Prospective, randomized, controlled,
PTA+optional stenting vs. primary stenting (Astron - Biotronik)
Endpoints = Duplex based patency
PTA +
optional stenting
Intention to treat
On treatment
39
34
-
-
Lesion length
1Y patency (duplex)
8
8.4 cm
39%
Schillinger et al, unpublished – presented at EURO-PCR 2008
Donnerstag, 19. September 13
Primary
stenting
66%
p<.05
ABSOLUTE Vienna Trial
Prospective, randomized, controlled
– PTA vs. Absolute nitinol stent (Abbott Vascular)
Endpoints = Duplex based patency + Stent fractures
PTA +/- stent
Stent
Intention to treat
53
51
On treatment
36
68
12.7cm
13.2cm
31%
54%
-
2%
Lesion length
2Y patency (duplex)
2Y fracture rate
Schillinger et al, N Engl J Med 2006;354:1879-88, Circulation 2007.
Donnerstag, 19. September 13
9
p<.05
Binary restenosis @ 12 months (%)
restenosis vs. lesion length
Data from randomised trials
PTA
Stent
RESILIENT
FAST
ASTRON
FAST
ABSOLUTE
RESILIENT
Schillinger et al, unpublished – presented at EURO-PCR 2008
Donnerstag, 19. September 13
ABSOLUTE
ASTRON
Lesion length (cm)
Stent Design
First generation:
Stent rings connected with longitudinally
oriented bridges
Donnerstag, 19. September 13
Stent Design
First generation:
Stent rings connected with longitudinally
oriented bridges
Donnerstag, 19. September 13
Stent Design
First generation:
Stent rings connected with longitudinally
oriented bridges
Donnerstag, 19. September 13
Stent Design
First generation:
Stent rings connected with longitudinally
oriented bridges
Second generation
Stent rings connected with helically
oriented bridges or
peak-valley bridge
Donnerstag, 19. September 13
SFA Stents
peak-peak or peak-valley bridge
Donnerstag, 19. September 13
SFA Stents
peak-peak or peak-valley bridge
Donnerstag, 19. September 13
Stentdesign
spiral cell connection
designed to disperse
force uniformly
peak to peak connection nodes
Helical bridges: to combine flexibility,
fracture resistance, radial force
resists compression
and provides excellent
wall apposition
three wave peak design
Lifestent
Donnerstag, 19. September 13
PROTÉGÉ® EverFlex
Supera Stent
Six pair of closed end interwoven nitinol wires
with a closed cell geometry
– flexibility
– strength
– fracture resistance
Supera
Donnerstag, 19. September 13
Supera Stent
Six pair of closed end interwoven nitinol wires
with a closed cell geometry
– flexibility
– strength
– fracture resistance
Supera
Donnerstag, 19. September 13
Superficial Femoral Artery (SFA)
• SFA steno-occlusive disease:
– Short lesions (<5 cm)
– Intermediate lesions (5-15 cm)
– Long lesions (>15 cm)
• Long-term patency of PTA in CLI is much lower
than in claudicants: 20-37% 3-year PP
• Different attempts to reduce low patency due to:
– Recoil
– Dissection
– Intimal hyperplasia
Donnerstag, 19. September 13
Choice of Treatment
• Short lesions (>5cm):
– PTA with provisional stenting
• Intermediate lesions (5-15 cm):
– PTA with self-expandable stent
(Level 1a, Grade B)
(Level 1b,
Grade B)
• Long lesions (>15 cm):
– Venous bypass
Especially beneficial in patients with life-expectancy
>2 years (Level 1b, Grade B)
– Synthetic bypass
– thru pass for pts at high risk for
open surgery
(Level 3b, Grade C)
Setacci C, de Donato G, Teraa M, Moll FL, Ricco JB, Becker F, Robert-Ebadi H, Cao P, Eckstein HH, De Rango P, Diehm N, Schmidli J, Dick F, Davies AH,
Lepantalo M, Apelqvist J. Guidelines for critical limb ischaemia and diabetic foot. Chapter IV: Treatment of critical limb ischaemia. Eur J Vasc Endovasc Surg. 2011
Dec;42 Suppl 2:S43-59.
Donnerstag, 19. September 13
how do you choose your stent?
stent is stent, it does not matter
price is value
stentdesign
chronic outword force (COF)
diameter:
oversize, undersize, medium size, exact
size
Donnerstag, 19. September 13
stenting: what can go wrong ?
Oversizing:
1mm
Excentric Lesions
Ø6mm Stent
Ø5mm
Lumen
COF
Ø6mm Stent
Ø6mm
Lumen
Donnerstag, 19. September 13
In SFA & Popliteal Stent/Vessel Diameter Changes with
Leg Motion Bent Leg: 6 mm stent
4.38 mm
Change in vessel diameter causes
variable and increasing chronic
outward force
3.31 mm
4.12 mm
2.98 mm
3.92 mm
3.12 mm
5.13 mm
5.02 mm
Stent-vessel diameter range:
5.13 - 3.31 mm
Nikanorov A et al. J Vasc Surg. 2009; 5 supplement: S24.
Nikanorov A ., Schillinger M., ZHAO H., Minar E., Schwartz L. (2009).
Assessment of Self-Expanding Nitinol Stent Deformation after Chronic
Implantation into the Superficial Femoral Artery. Unpublished manuscript.
Donnerstag, 19. September 13
Stent-vessel diameter range:
5.02 - 2.98 mm
Self-Expanding Stents Are
Not Designed the Same
Increasing Outward Force
Stent Designs with Different Behaviors
Expansion force increases
with decreasing diameter
Flat expansion force
Donnerstag, 19. September 13
Stents Must be Designed for a
Broad Range of Vessel Diameters
Bent Leg: 6 mm stent
Stent-vessel diameter range,
5.02 - 2.98 mm
Ideal Stent Design
• Flat expansion force curve across a broad range of zero
• Less concern for precise vessel sizing to minimize COF
Increasing Outward Force
Stent Designs with Different
Behaviors in the Range
COF, chronic outward force.
Test(s) performed by and data on file at Abbott Vascular.
Nikanorov A et al. J Vasc Surg. 2009; 5 supplement: S24.
Nikanorov A ., Schillinger M., ZHAO H., Minar E., Schwartz L. (2009). Assessment of Self-Expanding Nitinol Stent
Deformation after Chronic Implantation into the Superficial Femoral Artery. Unpublished manuscript.
Donnerstag, 19. September 13
Expansion force
increases with
decreasing diameter
Flat expansion
force across
broad range of
diameters
Less Optimal SFA Stent Design
Increasing Outward Force
SFA long-lesion (bent knee): 6-mm stent
Vessel Diameter Range: 5.02 - 2.98 mm
COF, chronic outward force; SFA, superficial femoral artery.
Noted diameter range stated per instructions for use.
Test(s) performed by and data on file at Abbott Vascular.
Donnerstag, 19. September 13
Less Optimal SFA Stent Design
Increasing Outward Force
SFA long-lesion (bent knee): 6-mm stent
Vessel Diameter Range: 5.02 - 2.98 mm
Design limits
usage range
45 N
16 N
• Design limits use to a
smaller diameter range
• Design induces high COF
and, therefore, more vessel
irritation
COF, chronic outward force; SFA, superficial femoral artery.
Noted diameter range stated per instructions for use.
Test(s) performed by and data on file at Abbott Vascular.
Donnerstag, 19. September 13
Optimized SFA Stent Design
SFA long-lesion (bent knee): 6 mm stent
Vessel Diameter Range: 5.02 - 2.98 mm
Increasing Outward Force
Absolute Pro (6x100 mm Stent)
COF, chronic outward force; SFA, superficial femoral artery.
Noted diameter range stated per instructions for use.
Test(s) performed by and data on file at Abbott Vascular.
Donnerstag, 19. September 13
Optimized SFA Stent Design
SFA long-lesion (bent knee): 6 mm stent
Vessel Diameter Range: 5.02 - 2.98 mm
Increasing Outward Force
Absolute Pro (6x100 mm Stent)
• Design allows use
for a larger
diameter range
Design allows
broader usage
13 N
11 N
• Design induces low
COF and therefore
less vessel irritation
COF, chronic outward force; SFA, superficial femoral artery.
Noted diameter range stated per instructions for use.
Test(s) performed by and data on file at Abbott Vascular.
Donnerstag, 19. September 13
Goals to Optimized Stent Design and
Clinical Performance
✓
Stent selection is critical
✓
Minimize restenosis risk
with reduced COF
Not all self-expanding
stents are the same
Maximize usage range for each size
✓
✓
✓
✓
✓
“Easy to Choose”
“Easy to Use”
Provide optimum scaffolding to promote healing and maintain
patency without fracturing
Donnerstag, 19. September 13
Goals to Optimized Stent Design and
Clinical Performance
✓
✓
Stent selection is critical
Not all self-expanding
stents are the same
Thank you for your ✓attention
Minimize restenosis risk
with reduced COF
✓
Maximize usage range for each size
✓
✓
✓
“Easy to Choose”
“Easy to Use”
Provide optimum scaffolding to promote healing and maintain
patency without fracturing
Donnerstag, 19. September 13
www.gefaessmedizin.ch
Donnerstag, 19. September 13