General Principles - VascularWeb

9/12/2011
SVS Comprehensive Vascular Review Course
September 9-10, 2011
Intercontinental Chicago O’Hare
Disclosure
• I have no relationships to disclose.
Endovascular Therapy
-General Principles-
Mark G Davies,
MD, PhD, MBA
• I have no unlabeled or unapproved uses of
drugs or devices in my presentation.
“If something can go wrong, it will”
“If something can go wrong, it will”
Murphy’s Law
Murphy’s Law
“Anything that can go wrong, will—at the
worst possible moment”
Finagle’s Law
Develop skills with a narrow repertoire of
catheters and wires
80% of the problems will occur in 20% of
the cases
No fault in stopping
• Pre-operative
• Access
• Platforms
• Solutions
• Complications
• Followup
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9/12/2011
• Pre-operative Imaging
– CTA or MRA
– Echolucency
– Atherosclerosis vs. clot
• Better access
• Choice and availability of Platforms
• Reduction in Radiation and Contrast
A
Supra-Renal
Aorta
Renal Arteries
Iliac Arteries
Aorto-Iliac
Runoff
Infra-Renal
Aorta
Femoral
Arteries
B
CFA
Femoro-popliteal
Runoff
C
Popliteal
Tibial Vessel
runoff
SFA
Tibial
Vessels
Popliteal
Pedal
Vessels
• Pre-operative Pharmacology
– ASA, Plavix
– Statins
– Normal Saline
• Mucomyst
• Bicarbonate
– Antibiotics
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9/12/2011
• Pre-operative
• Access
• Platforms
• Solutions
• Complications
– Prevention
– Correcting
• Followup
Deep circumflex
iliac
Inferior
epigastric
CFA
PFA
SFA
21 GA
• Ultrasound access
• Micropunctures kits
• Direction
– Retrograde Iliac
– Antegrade UE
– Antegrade LE
– Retrograde Pop or Tibial ( DP or PT)
• Length and redundancy
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9/12/2011
Femoral Arterial Access With Ultrasound
Trial [FAUST]
• Routine real-time US guidance improved
CFA cannulation only in patients with high
CFA bifurcations but reduced the number
of attempts, time to access, risk of
venipunctures, and vascular complications
in femoral arterial access
Seto AH, Abu-Fadel MS, Sparling JM, Zacharias SJ, Daly TS, Harrison AT, Suh WM, Vera JA, Aston CE, Winters RJ, Patel PM,
Hennebry TA, Kern MJ. Real-time ultrasound guidance facilitates femoral arterial access and reduces vascular complications: FAUST
(Femoral Arterial Access With Ultrasound Trial). JACC Cardiovasc Interv. 2010 Jul;3(7):751-8.
• Vascular complications associated with arterial access are
recognized to occur during cardiac catheterization and
percutaneous intervention procedures
• Reported complication rates

9/12/2011
• Pre-operative
• Access
• Platforms
• Solutions
• Complications
– Prevention
– Correcting
• Followup
• Wire
– 0.035
– 0.018
– 0.014
• Sheath
–4Fr
–5Fr
–6Fr
• Guide
– 4Fr systems
• Delivery
–OTW
– Monorail
• Leading edge
• Shaft strength
Guidewires
Wire Component
• Wire tip
• Mandrel
• Cover
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Wire Characteristics
• Length
• Thickness
• Tip design
• Stiffness
• Hydrophilic coating
• Unseen and Unguided Wire = Dissection
• Push back on the wire = Dissection
• Right of the Spine = Venous Stick
• Lateral of the femur = Profunda
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9/12/2011
Torque Devices
Catheters
• Probe lesions
• Avoid buckling or coiling
the wire proximal to lesion
• Platinum tips will deform
and kink
“Work the Wire!”
Characteristics
• Tip design
• Stiffness
• Tourqability
• Hydrophilic coating
• Radio‐opacity
• Length
• Diameter
• Hole(s)
Length
• Depends of the distance of the work area
from the access site
• Short catheters (60‐65 cm), usually sued for
iliac work or with antegrade femoral access.
• Intermediate catheters (90‐110 cm) for
contralateral femoral or popliteal work or
carotid artery work
• Long catheters (130‐150 cm) for contralateral
tibial artery work
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34
• Bown MJ, Bolia A, Sutton AJ. Subintimal
angioplasty: meta‐analytical evidence of
clinical utility. Eur J Vasc Endovasc Surg.
2009 Sep;38(3):323‐37.
• Pooled estimates
– technical success: 85.7%
• (95% confidence interval: 83.3%‐87.7%, 2810 limbs),
– primary patency at 12 months : 55.8%
• (95% confidence interval: 47.9%‐63.4%, 1342 limbs)
– limb salvage at 12 months: 89.3%
• (95% confidence interval: 85.5%‐92.2%, 2810 limbs),
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9/12/2011
Catheter diameter
• Equal to the outer circumference of the
catheter (French size)
• Catheter size determines the wire size
that can be used with it:
– 2 –3 French use 0.018 or 0.014 inch wires
– 4 –5 French use 0.035 or 0.038 inch wires
• Larger sizes catheters are usually used
as guiding catheters.
37
• Integrated dilator
• Hemostatic valve
• Side port
• The size is the size of
the lumen
• 1 French size = 3.3mm
Sheath
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Guiding Catheters
• Dilator is not always
integrated
• No hemostatic valve at the
hub
• Needs a hemostatic
component e.g. Touhy‐Borst
• The size is the outer
circumference
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• Pre-operative
• Access
• Platforms
• Solutions
• Complications
– Prevention
– Correcting
• Followup
• Balloons
– 0.035
– 0.018
– 0.014
• Pressure
• Length
• Conformable
• Other Balloons
–Cryo
–Ultra HP
– Cutting
• Stents
– Regular
– Closed Cell
–Flexible
– Covered
– Biodegradable
• Atherectomy
– Directional
– Rotational
– Remote
endarterectomy
• Laser
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9/12/2011
Angioplasty Balloons
44
Balloon Angioplasty
• Remains the most effective and widely used
percutaneous technique
• Controlled stretch injury:
– Desquamation of endothelial cells
– Splitting or dissection of plaque and intima
– Stretching of the media
– Platelets and fibrin cover the denuded area
– Intima reendothelializes, artery remodels
– If intimal healing is prolific, restenosis occurs
Balloon Characteristics
• Size
• Platform size
• Profile
• Pushability
• Tractability
• Pressure rating
• Compliance
46
• Sachs T, Pomposelli F, Hamdan A, Wyers M,
Schermerhorn M. Trends in the national
outcomes and costs for claudication and
limb threatening ischemia: Angioplasty vs
bypass graft.J Vasc Surg. 2011 Aug 29. [Epub
ahead of print]
• Mortality is slightly lower with PTA for all
indications, amputation rates for limb‐threat
patients appear higher, as does the average
cost
• E Y, He N, Wang Y, Fan H. Percutaneous
transluminal angioplasty (PTA) alone
versus PTA with balloon‐expandable stent
placement for short‐segment
femoropopliteal artery disease: a
metaanalysis of randomized trials. J Vasc
Interv Radiol. 2008 Apr;19(4):499‐503.
• In the treatment of femoropopliteal artery
occlusive disease (< or =10 cm), higher
primary patency rates can be expected at 6
months with PTA followed by implantation
of balloon‐expandable stents versus PTA
alone
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9/12/2011
• Mwipatayi BP, Hockings A, Hofmann M,
Garbowski M, Sieunarine K. Balloon
angioplasty compared with stenting for
treatment of femoropopliteal occlusive
disease: a meta‐analysis. J Vasc Surg. 2008
Feb;47(2):461‐9
• Stent placement in the femoropopliteal
occlusive disease does not increase the
patency rate when compared with
angioplasty alone at 1 year.
• CochTwine CP, Coulston J, Shandall A,
McLain ADAngioplasty versus stenting for
superficial femoral artery lesions. rane
Database Syst Rev. 2009 Apr 15;(2):CD006767.
• There is limited benefit to stenting lesions of
the superficial femoral artery in addition to
angioplasty.
Specialty Balloons
• Cryoplasty Balloons
• Cutting Balloons
• Scoring Balloons
Cryoplasty Balloons
• The PolarCath (Boston
Scientific)
• Employs cold therapy
using nitrous oxide as
the inflation material
• The concept of inducing
apoptosis via freezing
to reduce intimal
hyperplastic response
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52
• Lyden SP. Indications and results with
cryoplasty in the treatment of infrainguinal
arterial occlusive disease. Vascular. 2006
Sep‐Oct;14(5):290‐6.
• Cryoplasty yappears to improve patency over
conventional angioplasty and to reduce the
need for bailout stenting in femoropopliteal
stenoses and occlusions < 10 cm in length.
• Cutting Balloon
(Boston Scientific).
• The device has four
longitudinal
microsurgical blades
attached to the
balloon (atherotomes)
• Allow for more
controlled fracture
and dilation of the
vessel
Cutting Balloons
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9/12/2011
• Angiosculpt
(AngioScore, fremont,
CA)
• Similar to cutting
balloons but instead of
atherotomes, it uses a
flexible nitinol scoring
element with three
rectangular spiral struts
Scoring Balloons
• Canaud L, Alric P, Berthet JP, Marty‐Ané C,
Mercier G, Branchereau P. Infrainguinal
cutting balloon angioplasty in de novo
arterial lesions. J Vasc Surg. 2008
Nov;48(5):1182‐8.
• CB‐PTA is safe and feasible for the treatment
of infrainguinal arterial occlusive disease,
with relatively low mid‐term restenosis rates
compared to other endovascular treatments
• Lesions

9/12/2011
Stents
• It is said that the term Stent originated
from Charles R Stent, a 19 th century
British Dentist naming a dental
apparatus used form making molds
“Stent”
• Dotter was the first to apply metallic
stents to the human vascular tree.
61
• High radial force
• Resistant to recoil
• Minimal or no
stimulation of intimal
hyperplasia
• Longitudinal
flexibility
• High radiopacity for
visualization
• Ability to conform to
Ideal Stent
• Low profile
• Minimal or no
foreshortening
• Easy deployment
system
• Maintenance of side
branch patency
• Magnetic resonance
imaging compatibility
• Durability
• Low price
the vessel
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Balloon Expanding
Stent Types
• Mechanism of deployment
– Self‐Expanding stents
– Balloon‐Expanding stents.
• Bare metal stents or Covered stents
(stent grafts)
• Special types of stents
– Drug eluting stents
– Bio‐degradable stents
Pros
Balloon Expandable vs
Self Expanding
Balloon Expandable Stents Self Expanding Stents
Accurate deployment
Strong radial force
Radio-opaque
Flexible
Long
Crush resistant
Cons
Rigidid Insufficient i radial force
Short
Insufficient radio-opacity
Crushable
Less accurate deployment
Uses
Orificial lesions
Calcific lesions
Resistant lesions
Superficial lesions
Long lesions
Tortuous lesions
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64
Balloon Expandable Stents
• Slotted malleable
metal tubes expanded
by a coaxial balloon
matched to target
vessel diameter
• Most are made of
stainless steel alloy
Self Expanding Stents
• Have a natural shape that is based on
their mechanical or thermo‐mechanical
properties.
• Walstents are the prototype of the
mechanical self expanding stents.
• Nitinol stents are the prototype of the
thermo‐mechanical stents.
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Nitinol Stents
• Nickel and titanium alloy (50‐55% Nickel –
45‐50% Titanium).
• It possesses thermal memory
• Memory is set at high temperature (1,000° F)
• At the transition point (90° F) the alloy
regains its shape
• Below the transition point, the metal is pliable
Nitinol Stents
Lifestent
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Nitinol Stent Implantation Versus Balloon
Angioplasty for Lesions in the Superficial Femoral
Artery and Proximal Popliteal Artery - Twelve-Month
Results From the RESILIENT Randomized Trial
• At 12 months, freedom from target lesion
revascularization was 87.3% for the stent group
compared with 45.1% for the angioplasty group
(P

9/12/2011
Covered Stents
• "ideal indications" for stent graft
– segments with a length of ≥1 cm proximal and
distal without any obstruction,
– no lesions in the popliteal artery
– one open tibial vessel
– no severe calcifications
– adequate antiplatelet therapy or
anticoagulation),
• McQuade K, Gable D, Pearl G, Theune B, Black S.
Four-year randomized prospective comparison of
percutaneous ePTFE/nitinol self-expanding stent
graft versus prosthetic femoral-popliteal bypass in
the treatment of superficial femoral artery
occlusive diseaseJ Vasc Surg. 2010 Sep;52(3):584-
90; discussion 590-1, 591.e1-591.e7.
• Management of superficial femoral artery
occlusive disease with percutaneous stent
grafts exhibits similar primary patency at 4-year
(48 month) follow up when compared with
conventional femoral-popliteal artery bypass
grafting with synthetic conduit
To debulk or not…
Device Advantages Limitations
Famiarity to IC
Effective with calcium
Heat Generation
Larger particle sizes than OA
• Rotational
• Excimer Laser
• Directional
Atherectomy
• Orbital Atherectomy
• Pathway Athectomy
No wire exchange
Eliminates thrombus
Effective on soft plaque
Challenged with Calciuc
Effective on calcium
Lumen size varies by
speed of rotation
Aspiration included
Blades up increases lumen
size
Limited with calcium
Contact ablation only
Distal embolization risk
Prolonged procedure time
Potential for complications with poor
technique or large crown size
Unable to treat

9/12/2011
• Distal Embolization
– Emboli occur during wire crossing,
angioplasty, stent deployment and
atherectomy
– 55% of patients can be shown to have
macroembolism (PROTECT registry)
– ~1% have been reported to result in
angiographic loss of runoff
• Distal Embolization
– PROTECT registry angiographic criteria:
• moderate or severe calcification of any length
• total occlusions of any length
• a filling defect
• irregular (ulcerated) lesions at least 30 mm in
length,
• smooth, non-ulcerated lesions at least 50 mm
in length
– Collected particles consisted primarily of
platelets and fibrin conglomerates, trapped
erythrocytes, inflammatory cells, and
extracellular matrix
Incidence
Processes Leading to Restenosis
In situ
Thrombosis
Distal
Embolization
3.5% 3.8%
• Pre-operative
• Access
• Platforms
• Solutions
• Complications
– Prevention
– Correcting
• Follow up
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9/12/2011
Reporting Standards
• Primary Patency
• Assisted Primary
Patency
• Secondary Patency
• Survival
• Limb Salvage
• Target Lesion
Revascularization
• Target Extremity
Revascularization
• Symptom Free
• Clinical Efficacy
• Amputation Free
Survival
• MACE, MALE, 30d
Amp
• “Keep it simple”
• “Do not do the economic patient”
• “Do not attempt the impossible!”
• “First, do no harm”
• “If Plan A does not work, do not try plan A
again”
• “There is always bypass”
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