Treatments in PAD:Balloons and Stents

D. Chris Metzger, MDBallad Health System CVA Heart & Vascular Institute

Kingsport, TN, USA

Disclosures• Symposia Honoraria & Proctor Fees:

– Abbott, Endologix/ TriVascular• Symposia Honoraria:

– Boston Scientific, Bard, Gore, CSI, Medtronic • VIVA Board Member• National PI/Co-PI: Confidence, SAPPHIRE WW, CANOPY• Research Grants, Stocks, Equity

– None

“Balloons & Stents in PAD”

Balloons

• Standard angioplasty balloons (POBA)• Specialty/ Focal force balloons • Shockwave lithotripsy angioplasty• Drug coated balloons (DCB)

Stents

• Nitinol stents• Drug Eluting Stents• Interwoven Stents• “Tacks”

Standard PTA Balloons (POBA)• Consider…. We use at least some balloon during almost every

interventional procedure that we perform• You need a ~ complete inventory of balloons• Not commonly “stand alone” definitive therapy above the knee

– Long term results suboptimal, worse than other treatment strategies– Mechanism is “controlled” ~plaque dissection

• Often may be stand alone therapy below the knee• Your choice of balloons and use of them will depend on your

intended ultimate treatment strategy

POBA- cont’d..• When you ask for and open balloons, important to carefully

open the correct balloon (Staff AND Doc)– Long shaft vs short shaft; .014 vs .018 vs. .035

• Prep the balloon well, watch for “twisted balloon” during inflations (remove if occurs)

• The performance of your first balloon and the angio after PTA (with balloon in place) often helps determine next device used– We often balloon with roadmap AND leg tape for sizing help– More balloon needed, NC shorter balloon, stent length, DCB OK?

Balloon Considerations• Leg rulers and tape help immeasurably (use them)• There are LONG balloons available (up to 300mm)

– Make sure you know which is the TRUE distal end when inflating!• If “trouble areas” with long balloon, use shorter balloons there• If considering a non-stent strategy, GOOD ANGIOPLASTY

TECHNIQUE is essential to success– SLOW Inflations AND deflations– Long Inflations : at least 2-3 minutes– Correct sizing and positioning of balloon

Proper Angioplasty TechniquesKey to Success of PTA &DCB’s

• Pre-dilate w/ smaller balloon (1mm ≤ DCB)• SLOW inflations AND deflations• LONG inflations (≥ 3 minutes per PTA)• ~“Normal to normal” segment PTA/ DCB• Want to avoid major dissections while also “preparing” lesion for

easy delivery of DCB• Proper PTA improves POBA results

In.PACT.SFA;TCT 2014; J.Laird

PTA controls 12 month primary patency 56.8-66.8%

Specialty Balloons

Angiosculpt Scoring Balloon

Vessel PreparationChocolate™ PTA Balloon Catheter

Pressure Relief Grooves Uniform Dilation Pillows

Nitinol constraining structure

Unique nitinol constraining structure reduces the strain and trauma induced on the vessel wall during inflation through the use of "pillows" and “grooves” to relieve stress, modify the plaque and uniformly distribute circumferential forces to minimize vessel wall trauma

Potential Solution to minimize vessel dissection

CHALLENGES WITH STANDARD PTA

Uncontrolled PTA Balloon Inflation

3. Longitudinal (Elongating)

Stress & deformation to vessel wall = Vessel Trauma

1. Torsional (Twisting) 2. Radial (Expanding)

Flow limiting vessel dissection

Types of Stresses

Can lead to

CHOCOLATE PTA BALLOON

PTA verses Chocolate PTA inflation

Specialty Balloons Considerations

• More expensive that PTA balloons, no extra reimbursement• Predictable give larger lumens with less dissection (+data)• Good angioplasty technique VERY important• We love them, and use them selectively when benefit needed

– Vessel prep before DCB’s– Post atherectomy– In no stent zones or situations– CFA, popliteal, internal iliacs, profunda, small vessels

Shockwave Lithotripsy Angioplasty• Excellent for severe circumferential CA++• Less distal embolization than atherectomy devices• LOW dissection rates in heavy calcium• Have BTK sizes now; ATK 4-7 X60 balloons (one length -60mm)• Outstanding in heavily CA++ CFA, iliacs, distal aorta• Can use “kissing shockwave” in aorta• Useful for iliac/aortic preparation before TAVR, EVAR• NOT reimbursement code yet

CA++ RCIA, RCFA; difficult contralateral access

Shockwave 7X60 RCIA

Drug Coated Balloons (DCB)

• Excellent results and clearly superior to PTA• Durable results now published to 5 years• “Leaves nothing behind”- future options wide open• Helpful for ISR (after atherectomy in many, w/dEPD considered)• Needs good “vessel preparation” (then DCB OK?); proper sizing

Good angioplasty technique required

In.PACT.SFA;TCT 2014; J.Laird

PTA controls 12 month primary patency 56.8-66.8%

• An individualized risk/benefit consideration is important, as well as documented informed consent discussions

What about the DCB Controversy?

Advantages of Stenting in the SFA• High technical success rates with excellent acute results• Beautiful angios- “stent- like results”• Short procedural times• Low complication & distal embolization rates• Provides scaffolding stability to vessel• Well studied with ~ favorable data• Widely applicable to most operators

Stenting vs. POBA

Extension / Contraction 1.

Torsion

2.

Compression

3.Flexion 4.

The SFA and Popliteal Arteries Are Complex!

Nitinol Stents; DES

• Advantages:– Easy to deploy accurately, many sizes available– Well studied; familiar to all, “user friendly”– Lower cost– DES add biologic benefits to a nitinol stent platform (Zilver PTX, Eluvia)– DES advantages: superior to PTA and provisional BMS– Better data for ISR and long lesions than BMS

Problems with NitinolSlotted -Tube Stents

• Limited stent flexibility in a dynamic artery• Suboptimal radial strength• Exert ↑↑ outward force on vessel→ irritation• Limited conformability• POOR results in popliteal, CFA, adductor canal• Kinking (flexion points); Fractures ( w/ lengths)• Poor performance in heavy calcium, long dz.• These issues are magnified in long SFA disease

Stents do better than PTA, but..• Traditionally (STNS), the longer the lesion, the worse the

patency, and there are ↑ late problems• They don’t work well in heavy CA++• “They keep coming back” and “they are harder to treat”

12 months restenosis vs. lesion length

Lesion length (cm)

Bin

ary

rest

enos

is @

12

mon

ths

(%)

PTA + provisional stent

Stent

FAST

FAST

RESILIENT

ASTRON

ABSOLUTE

ABSOLUTE

ASTRON

RESILIENT

Data from randomised trials

Modified from Schillinger et al, EURO-PCR 2008

SFA: “Length Matters”

FACT

DurabilitySUPER SL SMART

SUPERA SFA

Supera is a UNIQUE Stent:Markedly Different from Other Stents

Available Nitinol Stents are “Slotted-Tube”--Laser cut from nitinol tubes– Open cell Design/ geometry

Supera is an Interwoven Nitinol Stent– The design incorporates 6 pairs of super-elastic nitinol wires which

are interwoven in a helical pattern with a closed cell geometry

Supera Interwoven Stent“Vascular-mimetic”

• High radial strength (>4X STNS); – ↑↑compression resistance

• Physiologically flexible/ conformable• Kink and crush resistant• ~Fracture proof• Lowest chronic outward force exerted

Supera has the Least Chronic Outward Force

Potential Clinical Advantages of Interwoven Stents (>STNS)

• Flexion points (CFA, popliteal, adductor)• Calcified lesions• Long lesions• Less irritation (↓COF), ↓ neointimal hyperplasia• Better durability and conformability• Better “stand alone” results• Much better IVUS and “bent knee angiographic”

results

Interwoven Stents and Viabahn Stent grafts• Both of these stents have good results which are ~

independent of lesion lenghts• Both have ~ no stent fractures• Viabahn has good data for “re-lining” ISR• Viabahn has lower radial strengths, is prone to “edge

restenosis”, and anecdotally can occlude abruptly (lysis works)• Vessel prep: aggressive PRE- treatment needed for Supera,

proper sizing (NOT oversizing for both), can aggressively POST treat Viabahns

Solution?: Place MINIMAL stent, ONLY Where They are Needed

CAUTION: Investigational device.Tack Endovascular System is limited by Federal (United States) law to investigational use. Not approved for sale in the United States.Tack Endovascular System is CE Mark authorized under EC Directive 93/42/EEC.Tack Endovascular Sytem™ and Tack™ are trademarks of Intact Vascular.

Tack™ Implant

Nitinol with gold radiopaque markers

Unique anchoring minimizes migration

Pin-Pull delivery technique

Standard over-the-wire system

Length: 120 cmWire: 0.035”

Designed for high-accuracy Tack deployment

Delivery System

Tack Endovascular System™

Tack Endovascular System TM 1.5Key Components

Delivery system• Pin and Pull Technique• Delivery catheter• # of Tack Implants• Working length• Guidewire

6F (2.0mm) catheter6120 cm0.035”

Tack Implant• Length• Reference Vessel Diameters• Radiopaque markers• Anchors

~ 6.0 mm2.5 – 6.0 mm66 pairs

Conclusions

• There are a LARGE array of available balloon and stent choices and treatment strategies

• Proper technique and selection are required for all devices• Each strategy should be individualized to the patient and

lesion, and modified as necessary throughout the procedure

Thank You Very Much for Your Attention!