GB Perera, MD

McLeod Heart and Vascular Institute

02-07-2011

Disclosure Information

• The speaker does not have any financial relationships to disclose.

• Overview PAD– Spectrum of clinical disease we see

Asxo vs. Claudication vs. CLI

• Dx– Clinical exam

• Normal vs. Abnormal

– Non-invasive physiological studies ABI

– Radiological studies: what to get and pitfalls• Rx modalities:

– Open: fem-pop, fem-distal, Remote atherectomy

– Endovascular Rx’s: Focus of this talk• Examples/Future Directions

N= 1079, retro, GFR < 60 and ABI < 0.9

• Pulse Examination– Carotid – Radial/ulnar– Femoral– Popliteal– Dorsalis pedis– Posterior tibial– Doppler (3)

• Scale:– Absent– Present

• Bilateral arm blood pressure (BP)

• Cardiac examination

• Palpation of the abdomen for aneurysmal disease

• Auscultation for bruits*

• Examination of legs and feet

Key components of the vascular physical examination include:

http://www.nhlbi.nih.gov/health/dci/Diseases/pad/pad_diagnosis.html

ABI=ankle-brachial index; DP=dorsalis pedis; PT=posterior tibial; SBP=systolic blood pressure.

Right ABI80/160=0.50

Brachial SBP160 mm Hg

PT SBP 120 mm Hg

DP SBP 80 mm Hg

Brachial SBP150 mm Hg

PT SBP 40 mm HgDP SBP 80 mm Hg

Left ABI120/160=0.75

Highest brachial SBP

Highest of PT or DP SBP

ABI(Normal >0.90)

• The toe-brachial index (TBI) is calculated by dividing the toe pressure by the higher of the two brachial pressures.

• TBI values remain accurate when ABI values are not possible due to non-compressible pedal vessels.

• TBI values ≤ 0.7 are usually considered diagnostic for lower extremity PAD.

• ABI must be interpreted in light of the clinical exam and scenario

• Exercise ABI’s if able

• Don’t just believe the number

• Waveforms: useful information

• Pressures: absolute, asymmetry

• Non-compressibility

• Trust your clinical exam

Claudication 10%-35%

5-year outcomes

Limb morbidity

Stable claudication 70%-80%

Worsening claudication 10%-20%

Critical limb ischemia 1%-2%

Amputation (see CLI data)

CV morbidity & mortality

Nonfatal CV event (MI or stroke) 20%

Mortality 15%-30%

CV causes 75%

Non-CV causes 25%

Reprinted with permission from Hirsch AT, et al. Circulation. 2006;113:e463-654.

Asymptomatic PAD 20%-50%

Atypical leg pain 40%-50%

For each of these PAD clinical syndromes

Natural History of Atherosclerotic Lower Extremity PAD

CLI=critical limb ischemia; CV=cardiovascular; MI=myocardial infarction

PAD Population (50 years and older)

Initial clinical presentation

Asymptomatic PAD 20%-50%

Atypical leg pain 40%-50%

Claudication 10%-35%

Critical limb ischemia 1%-2%

Progressive functional impairment

1-year outcomes

Alive w/ 2 limbs 50%

Amputation 25%

CV mortality 25%

5-year outcomes

(to next slide)

Reprinted with permission from Hirsch AT, et al. Circulation. 2006;113:e463-654.

Effect of Cilostazol on Walking Distance in Patients With Claudication

Beebe, et al. Arch Internal Medicine. 1999;159:2041-50.

60

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0 4 8 12 16 20 24

Mete

rs (

mean)

Weeks of Treatment

*

*

*

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** *

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* P < 0.05 vs. placebo

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MaximalWalking Distance

Pain-FreeWalking Distance

Cilostazol 100 mg bid(n=140)Cilostazol 50 mg bid(n=139)Placebo (n=140)

• contraction, expansion, compression, flexion, and torsion• SFA shortens up to 23% and the popliteal artery up to 14% with 90° knee

flexion. • After stent placement, the stented segment becomes more rigid than the

unstented segment, which must then shorten and flex more to accommodate the necessary vascular conformational changes.

• undesirability of placing stents in the distal superficial femoral artery (SFA) and popliteal artery

• 72% of SFA occlusions involve the adductor canal hiatus, the region where vessel mobility is greatest. This is also the segment where calcium deposition tends to be most frequent.

• TASC A– Single Stenosis < 3cm

• TASC B– Single Stenosis 3-5cm not involving Popliteal artery– Short occlusion <3cm– Multiple lesions, each <3cm

• TASC C– Long stenosis 5-10cm in length– Occlusion 3-5cm– Lesion of proximal SFA or distal Popliteal artery

• TASC D– Any Stenosis >10cm– Occlusion >5cm– Concurrent CFA occlusion– Distal Popliteal artery occlusion

• Endovascular procedure is the treatment of choice for Type A lesions; Surgery for Type D lesions

• More evidence is required to make firm recommendations regarding optimal treatment of Types B and C lesions

Don’t burn a surgical bridge

• POBA

• Subintimal Angioplasty (SIA)

• Cutting-Balloon Angioplasty (CBA)

• Stenting (SE, BE, stent grafts)

• Plaque Debulking

– Directional atherectomy (Silverhawk/Turbohawk)

– Rotational atherectomy (CSI Diamondback)

– Laser atherectomy

• Cryoplasty (PolarCath)

• CTO/re-entry devices

>80%

• Objective: Recanalization of occlusion

_________________• First described by Bolia

• Traverse occlusion in subintimal plane

• Re-entry into true lumen beyond occlusion

• Objective: Luminal gain with minimal vessel trauma

___________________

• Atherotomes

• Radially-arranged

• Longitudinally-oriented

STENTS

CTO devices*

• Create luminal gain

• Decrease risk dissection

• Try as “stand alone Rx”

• Tend to be lesion specific

• Activation of battery unit – Exposure of carbide cutter

• Rotation of carbide cutter at 8000 RPM

• Advance catheter thru lesion

• De-activate/Pack debris into housing

• Extracorporeally flush debris

• Objective: Plaque excision with minimal vessel trauma

____________________

• Developed to treat lesions insufficiently treated by POBA

• Eccentric, long-segment, branch-point lesions

• METHODS: Between August 2003 and February 2005• 19 institutions participating in the observational, nonrandomized, multicenter TALON

registry enrolled 601 consecutive patients (353 men; mean age 70+/-11, range 36-98) with 1258 symptomatic lower extremity atherosclerotic

• >2/3 claudicants• primary endpoints of the study were target lesion revascularization (TLR) at 6 and 12

months.• Lesion length >50 mm was associated with a 2.9-fold increased risk for TLR (HR 2.88,

95% CI 1.18 to 7.01, p=0.012); lesion length >100 mm was associated with a 3.3-fold increase in TLR (HR 3.32, 95% CI 1.15 to 9.56, p=0.016).

• CONCLUSION:

• favorable procedural success

• avoids the need for repeat revascularization at midterm follow-up.

• support PE as a primary endovascular therapy for patients undergoing lower extremity arterial revascularization.

• Eval Silverhawk atherectomy• Registry, non-randomized, 19 centers• 601 pts, 1258 limbs• Rx 6 cm above knee, 3 cm below knee• Weaknesses:

– TLR at 6 mo and 12 mo ( no clinically relevant data)– Most were SFA/pop; no sig tibial interventions– <1/3 CLI

• Strengths: – stents used only in 6%– Decreased rate of dissections

• COMPLIANCE 360° TRIALThe COMPLIANCE 360° trial is a multicenter, prospective, randomized study comparing balloon angioplasty to the Diamondback 360° system in treating calcium-containing, de novo

• femoropopliteal lesions• Bailout stenting may be used in either arm where a residual stenosis of

< 30% cannot otherwise be achieved using the intended therapy and will count as a target lesion revascularization (TLR) event for both arms.

• The primary endpoint is TLR or restenosis at 6 months with a secondary endpoint at 12 months. Restenosis is defined by a peak systolic velocity ratio of > 2.5 using duplex ultrasound. Both the angiograms and duplex ultrasound studies will be core lab adjudicated to maximize the legitimacy of the results

• COMPLIANCE 360° is a 50-patient pilot study that is currently enrolling.

• Brief Summary

• Official Title: “Determination of Safety and Effectiveness of the SilverHawk® Peripheral Plaque Excision System for Calcium (SilverHawk LS-C) and the SpiderFX Embolic™ Protection Device (SpiderFX) for the Treatment of Calcified Peripheral Arterial Disease in the Superficial Femoral and/or the Popliteal Arteries (DEFINITIVE Ca++)”

• This is a multi-center, non-randomized, single arm study of the SilverHawk/TurboHawk plaque excision systems when used in conjunction with SpiderFX in treatment of moderate to severely calcified peripheral arterial disease in the superficial femoral and/or popliteal arteries.

• Study Type: Interventional

• Study Design: Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

• Study Primary Completion Date: November 2010

• Daniel Clair, MD Principal Investigator The Cleveland Clinic  

Really???

• Objective: Improve restenotic rates of POBA

____________________

• Re-stenotic lesions are hyperplastic neo-intimal-type (depends)

• Induction of SMC apoptosis may reduce neointimal hyperplasia

•freezing thesurrounding vessel to -10°C and

•then allowing the vesselto slowly rewarm.

•causes apoptosis of thesmooth muscle cells

•alteration in the plaque response todilation and

•reduction of elastic recoil of the vessel wall.

• Initial stepwise inflation

• Liquid nitrous oxide delivered

• At inner balloon, liquid sublimates

into gas

• Balloon inflation

• Endothermic reaction produces heat

sink -10o

C

• 90 patients

• Moderate to severe claudication

• FP disease no longer than 10cm

• Technical success 85%

• Adjunctive stenting 6.9% (rel. low)

• 6 month Target vessel patency (duplex) 70%

• 9 month clinical patency 82%

J Vasc Interv Radiol 2005; 16:1067-1073

• Objective: Plaque ablation with minimal vessel trauma

____________________

• Excimer laser technology

• Modification of original Nd:YAG laser (too much thermal energy)

• Gained U.S. approval in 2004

• CVX300 laser

• CLirPath Extreme Catheter

• delivering very high energy in extremely short pulses.

• The "cool" excimer laser ablates tissue on contact (about 50 microns from the catheter's tip) without inducing thermal damage to the treated artery

• Concentrically-placed; longitudinally oriented optic fibers

• Diameter most 2.5-3mm

Not stand alone Rx

Tool for CTO

• 48 limbs (51 patients)

• Inclusion: ASA 4; no conduit; unsuitable target vessel

• 3 peri-operative deaths

• Procedural success 100%

• Stand-alone therapy 14%

• Adjunctive angioplasty 33%

• Adjunctive angioplasty/stent 47%

• 6 month limb salvage 90.5%

Eur J Vasc Endovasc Surg 2005;29:613-619

• Drug eluting balloons and stents in periphery

• Gene Rx/angiogenesis

• Tissue regeneration (Grow a new SFA/tibial)

• Better drug Rx’s

• Rx tibial and pedal disease is the challenge

• Trust your exam• ABI must be interpreted not just believed• Early Vasc referral• Paradigm shift: Limb Preservation (Clinic)

not Limb Salvage• CKD, DM, no pulses, Asxo -> Vasc consult• Endovascular “tune-up” vs. EndoRx followed by

amputation a few days later• Our only tool is not a hammer…• We need better clinical data on technology• Preserving the tibials is key• Endo first reasonable and surgical bridge• CO2 angiography: R.I.P. ….for now

• To receive the full powerpoint presentation with images, please contact Meghan Swink at MSwink@McLeodHealth.org. Thanks!