astoryofcoronarystent-140112114616-phpapp01.ppt

The story of the coronary stent
RAMACHANDRA

PREFACE
PCI is the most common procedure for cardiologist
POBA limited by dissections/ recoil/neointima/vessel
closure/restenosis
BMS limited by neointima[ISR- in 20%-30% of]
DES limited by late stent thrombosis(Polymer without
drug preventing endothelialisation)
BVS limited by cost, long experience is awaited

POBA
First successful balloon angioplasty
September 16, 1977
Zurich, Switzerland
 Andreas Gruentzig

STENT
The term “stent” derives from a dental prosthesis developed by the London dentist Charles
Stent (1807–1885),indicate any device used for “extending, stretching, or fixing in an expanded
state
The first stents were implanted in human coronary arteries in 1986 by Ulrich Sigwart, Jacques
Puel, and colleagues, who placed the Walls stent sheathed self-expanding metallic mesh scaffold
(Medinvent, Laus-anne, Switzerland) in the peripheral and coronary arteries of eight patients
 Cesare Gianturco and Gary Roubin developed a balloon-expandable coil stent consisting of a
wrapped stainless steel wire resembling a clamshell
 A phase II study evaluating the Gianturco-Roubin stent to reverse POBA in acute or
threatened vessel closure was started in 1988, ultimately leading to United States Food and Drug
Administration (FDA) approval for this indication in June 1993
Julio Palmaz stent devised a balloon-expandable slotted stainless steel stent with rectangular
diamond shaped slots is the mother of all the modern stents.

Gianturco-Roubin stent: Outdated
Cesare Gianturco and Gary Roubin
developed a balloon-expandable coil stent
consisting of a wrapped stainless steel
wire resembling a clamshell

Palmaz-Schatz stent
First coronary Palmaz-Schatz stent was
placed in a patient by Eduardo Sousa in São
Paulo, Brazil in 1987 with a US pilot study
started in 1988,is the mother of all recent
stents((Johnson and Johnson Interventional
Systems, Warren, NJ) )

Palmaz-Schatz stent
Palmaz-Schatz stent, the first stent approved by the
USFDA was introduced by Johnson and Johnson
(J&J) in 1994

First stent trial(s)
1989, two randomized multicentre studies (STRESS and BENESTENT) comparing POBA
to elective Palmatz-Schatz stenting. In these studies, 20% to 30% reduction in clinical and
angiographic restenosis compared with POBA. Palmatz-Schatz stent approved by the FDA
in 1994

The era and aura of DAP -1990
Antonio Colombo :reduced rates of stent thrombosis using
1.IVUS
2.routine high-pressure (>14 atmospheres)
3.Aspirin and a second antiplatelet(thienopyridine, ticlopidine) vs. warfarin

Stent Design
 Composition of strut: Metallic or polymeric
 Configuration: Slotted tube versus coiled wire
 Bioabsorption:Durable or bioabsorbable
 Coatings :None/ passive such as heparin/ PTFE
 Bioactive :Eluting rapamycin or paclitaxel in pores in
the stent wall or in polymer
Implantation:Self-expanding or balloon-expandable

Stent Composition
Non-self expanding :stainless steel- 100 to 150 μm thick and Cobalt
chromium/ platinum chromium alloys - lower-profile/ thin stent struts ( 75
∼
μm)
Self expanding: Nitinol, a nickel/titanium alloy that has super-elastic
Biodegradable stents:
 1.Polymer of L-lactic acid (PLLA)
 2. Non-polymeric :magnesium

Stent Configuration and Design
Design
Wire coils: First Gianturco-Roubin stent but later all three designs failed(Poor radial and
axial strength)-outdated
Slotted tubes/multicellular
Modular designs
Stent lengths (8 to 48 mm) and diameters (2.25 to 6.0 mm)
The initial modular stent was the Arterial Vascular Engineering Micro-Stent (subsequently
purchased by Medtronic Corp., Santa Rosa, CA), which had a series of 4-mm-long, rounded
stainless steel corrugated ring subunits welded to each other. Subsequent designs have
incorporated an ellipto-rectangular (rounded) strut profile and progressively reduced the
length of the individual modules, with progressive reductions in crossing profile and
increased surface area coverage.
Most of current stent from original Palmatz’ stent

Configuration
Depending on the cellular configuration, multicellular stents can be broadly sub classified
as either open cell or closed cell.
 Open cell (Not all struts interconnected, open area >5mm²) designs tend to have varying
cell sizes and shapes along the stent, and provide increased flexibility, deliverability,
and side branch access by staggering the cross-linking elements to provide radial
strength. Open cell designs thus tend to conform better on bends, though the cell area
may open excessively on the outer curve of an angulated segment
 Closed cell (Interconnected stent struts, open area <5mm²) designs typically
incorporate a repeating unicellular element that provides more uniform wall cover-
age with less tendency for plaque prolapse, at the expense of reduced flexibility and
side branch access. Closed cell designs also tend to straighten vessel bends more than
open cell designs.

Balloon-Expandable Versus Self-Expanding
Stents
Balloon-expandable
 1.Typically 1 to 1.1 times the reference arterial diameter
 2.Length several millimetres longer than the lesion
 3.. Almost all stents implanted in human coronary arteries
Self-expanding
1.Unconstrained diameter 0.5 to 1.0 mm greater than the adjacent reference segment
to ensure contact with the vessel wall and adequate expansible force to resist vessel recoil
2. Final optimization of stent expansion usually requires additional dilatation within
the stent using a high-pressure, noncompliant angioplasty balloon
3. Only few in use like The Cappella Sideguard Coronary Sidebranch stent

Indication
Elective
Bail-out

BMS
Coronary restenosis became known as the “Achilles’
heel” of coronary stenting
20-30% at 6 months ISR
Better than POBA[STRESS and BENESTENT-1 ]

BMS is better
Metaanalysis from 13 randomized
controlled trials of bare-metal stents
compared to balloon angioplasty in acute
myocardial infarction in 6,922 patients
(adapted from De Luca et al., Int J
Cardiol 2008)

Generations of Drug-Eluting Stents

Mortality using DES vs. BMS:Not difference

3RD
Generation
3rd
generation strut 3rd
generation polymer 3rd
generation drugs
Platinum chromium alloy biodegradable polymers,
polymer-free stents, and
biodegradable stents on the basis
of poly-L-lactide (PLLA) or
magnesium
Zotarolimus
Everelimus

Absorb, the 4th
Revolution in Interventional
Cardiology
Absorb defines a new paradigm - Vascular
Reparative Therapy (VRT). VRT is designed to
restore the vessel to a more natural state§
, making
natural vascular function possible

Implant Tech:The operator’s skill
Guide catheter
 Guide wire
Stent selection
Adjunctive :IVUS,FFR, OCT,atherectomy,
thrombectomy and distal protection devices

astoryofcoronarystent-140112114616-phpapp01.ppt

Complication of stenting
Thrombosis
Perforation(0.2% to 1.0%;balloon size>120% )
Dissection
Infectious Endarteritis
Allergic Reactions
Stent embolization
Side branch occlusion

Immediate complication of Stenting is ST

Risk factors for stent thrombosis

Minimum duration of DAP is 1 year

Bifurcation Stenting
20% or more of stenosis
Increased procedural complications
DES in main vessel
True bifurcation (+side branch >2mm
and diseased)
Provisional stenting(main vessel
stented first)

Strategies for bifurcation disease: Louvard et al., Heart 2004
1 & 2. Classic T-stenting beginning with side branch stenting
 3. Modified T-stenting=Mini crush
 4. “Crush” technique
 5. Classic T-stenting beginning with main branch stenting
 6. Provisional T-stenting
 7. Culottes' or trousers
 8. Touching stents completed or not as Y technique
 9.Trouser legs and seat
 10. SKS
 11. Skirt

Dedicated bifurcation
NILE PAX BIFURCATION STENT[Heart Beat intervention Pvt. Ltd. ]
The Axxess stent (Devax Inc., CA, USA)
The SLK-View™ stent (Advanced Stent Technologies, CA, USA)
Tryton Side-Branch Stent (Tryton Medical, Inc., MA, USA)
The Stentys™ coronary stent (Stentys SAS, Paris, France)

Conclusion
Stent but no in-stent restenosis or stent thrombosis
DIOR?
No polymer if no more drug(Prof Renu Vira mani-
2013)
Does the future lies in BVS?

astoryofcoronarystent-140112114616-phpapp01.ppt

More Related Content

Similar to astoryofcoronarystent-140112114616-phpapp01.ppt (20)

Recently uploaded (20)

astoryofcoronarystent-140112114616-phpapp01.ppt