Critical Limb Ischemia

Take Charge of CLI: Tools for Optimal CLI Revascularization

Paul Michael, MD, Wound Management & Limb Preservation Center, JFK Medical Center, Palm Beach, Florida

Paul Michael, MD, Wound Management & Limb Preservation Center, JFK Medical Center, Palm Beach, Florida

Treating end-stage peripheral arterial disease (PAD), better known as critical limb ischemia (CLI), is a daily challenge and requires what basketball player Kobe Bryant refers to as a persistent “Mamba Mentality”, defined as “constantly trying to be the best version of yourself.” After attending the Amputation Prevention Symposium (AMP) meeting in Chicago for the first time, I realized how little I knew about CLI and how much more there was to learn if I was going to dedicate my career to amputation prevention. Passion and hard work alone do not make a CLI operator; it requires the development of advanced skill sets necessary to take care of these “forgotten” patients. Best treatment strategies for CLI patients remain unclear, but we do know that by combining advanced training with the formation of specialized vascular teams, techniques can be extended across the vascular care continuum to offer patients their best shot at amputation prevention, because saving limbs means saving lives.1,2  To achieve this goal, CLI operators must first master interventional devices and advanced revascularization tools, a key take-home message of CLI education offered through conferences such as AMP. After performing thousands of CLI cases and trialing hundreds of devices, my diagnostic and treatment algorithm for amputation prevention therapy has been simplified into a basic formula: 1) Employ a radial-first diagnostic strategy; 2) Listen to the patient and the wound; 3) Plan the case; 4) Standardize alternative access; 5) Master multilevel, multivessel chronic total occlusion (CTO) crossing; 6) Use the right tool(s) for the job; 7) Employ non-radiation imaging modalities when needed; 8) Anticipate any complication; 9) Ensure wound-directed therapy. My guiding principle of CLI treatment is what I call “functional” revascularization, meaning that patients undergo purpose-driven therapy by a CLI team that focuses on achieving wound healing, with the end result encouraging a return to mobility, and ultimately, a functional quality of life for the patient.

Surgical and endovascular revascularization efforts frequently involve targeting infrapopliteal and inframalleolar lesions. These are particularly challenging because of their behind the knee and behind the ankle locations which receive excessive torsional stress and have variable reconstitution and morphology patterns. The ability to leave these vessels intact while maximizing outflow and future therapy options is of great importance. This creates a unique space for technology which can battle atherosclerosis and calcium in these territories, such as the versatile HawkOne directional atherectomy system. CLI “power tools”, as I like to call them, are not only versatile, but have special applications. Additional examples include nitinol-caged balloons such as the Chocolate PTA balloon for controlled dilatation and limiting dissections, and the IN.PACT Admiral drug-coated balloon (DCB) for antirestenotic therapy. Extra-long balloons such as the Pacific Xtreme PTA balloons have become a major power tool in our CLI shop, given their 300 mm length and .018-inch platform. These extra-long balloons make cases efficient as well as reduce dissection potential with prolonged inflations. The Pacific Plus balloons give operators the ability to go down to a 2 mm PTA balloon diameter, all while maintaining an .018-inch platform, if required. The tapered 2.0 mm(proximal)/1.5 mm(distal) NanoCross Elite PTA balloon is a go-to workhorse for “around the pedal loop” angioplasty, giving it a special place among CLI power tools. With the ability to access pedal vessels quickly and cross lesions retrograde through the access needle using CTOP-guided therapy3, the .018-inch 90 cm Trailblazer catheter technique has replaced sheath placement for many tibial access interventions. This involves advancing the .018-inch catheter over the wire directly through the skin in place of a sheath and quickly reversing access direction for antegrade intervention, followed by prompt removal of the Trailblazer support catheter. This CLI-fighting technique allows for direct visualization of arterial flow in the catheter and minimizes the puncture site size by eliminating the need for sheath placement when performed quickly.

With >95% of my current volume focused on limb salvage and amputation prevention, I need tools that offer predictable and safe results, with room for creative applications. The following cases demonstrate such applications and the “power tools” used to achieve a successful outcome.

Case Examples

Case #1

A 52-year-old diabetic gentleman presented through the emergency department with an occupational-related left foot wound. He was referred by the foot and ankle surgery team given his abnormal non-invasive findings and poor vascular physical exam, with a high suspicion for CLI. After initial angiography demonstrated a complex popliteal artery lesion compromising tibial inflow, an intravascular ultrasound (IVUS) catheter was used to assess true vessel sizing. Demonstrating its versatility, a 6 French (Fr) HawkOne M directional atherectomy device was used in the popliteal artery (Figure 1A) prior to prolonged inflation angioplasty with a 7 mm x 40 mm IN.PACT Admiral DCB (Figure 1B), all performed over a SpiderFX embolic protection device.

Case #2

This 67-year-old diabetic patient presented to the JFK Wound Management & Limb Preservation Center for a non-healing ulcer of the foot. Baseline angiography revealed an anterior tibial artery CTO compromising wound healing to the foot. This case highlights the routine workhorse utility of a highly maneuverable directional atherectomy device that can be easily used for tibial reconstruction. The ability to place embolic protection devices deep in pedal vessels allows one to confidently treat tibioperoneal vessels when needed, such as in Figure 2A, demonstrating safe placement of a filter in the dorsalis pedis artery to treat a long segment anterior tibial artery CTO with directional atherectomy using the TurboHawk SS-CL device (Figure 2B).

Case #3

This patient underwent foot and ankle surgery after a complex fracture from a motor vehicle accident. After hardware was implanted, this 62-year-old diabetic patient began to experience wound healing problems unrelated to hardware implantation. A baseline angiogram revealed chronic total occlusions of the anterior and posterior tibial arteries, requiring revascularization for wound-directed therapy (Figure 3A-C). Revascularizing tibiopedal vessels is of paramount importance to limb salvage and the ability to take devices beyond the inframalleolar level helps achieve this goal. There are many tools in our cath lab for tibial work, all of which have been taken below the ankle in antegrade and retrograde techniques. The TurboHawk SX-C, TurboHawk SS-CL, and HawkOne S devices are highly versatile, and can be maneuvered below the ankle in a flexible fashion to achieve atherectomy treatment goals (Figure 3A). I have incorporated intravascular ultrasound (IVUS) into my CLI therapy algorithm to help accurately size and treat these typically underestimated vessels. CLI often presents a multi-vessel, multi-segment challenge where getting to the final tibiopedal destination involves crossing an obstacle course of iliofemoral and femoropopliteal CTOs. Long shaft, long length, and low profile equipment helps overcome these challenges when multi-segment therapy is required.

Case #4

This 71-year-old woman presented to the CLI team after multiple, failed revascularization attempts and was offered a palliative below-knee amputation for pain control. The CLI team offered her an intervention with revascularization of her long segment SFA CTO. Michael Jordan is famous for saying, “I’ve never lost a game, I just ran out of time.” Time is an important factor in complex CLI cases. Tools that help revascularize faster for the “win” should be utilized. Long balloons (Figure 4), such as the .018-inch Pacific Xtreme PTA balloon catheter in up to 300 mm lengths, help save precious time and are routinely used in our lab from antegrade and retrograde approaches in treating long femoropopliteal lesions after directional atherectomy use (Figure 4B). When stenting the iliofemoral and femoropopliteal vessels is required from pedal access, having a versatile, low-profile 5 French delivery self-expanding stent comes in handy, and the Everflex self-expanding peripheral stent with Entrust delivery system performs well in these situations.

Case #5

This 66-year-old diabetic woman was referred by the foot and ankle residency team for ischemic digits and rest pain upon presentation to the emergency room. Her baseline angiogram revealed occlusions of her dorsalis pedis and plantar arteries. Pedal arch angioplasty (Figure 5) is frequently necessary with advanced tissue loss cases. Being able to preserve as much of the forefoot as possible prior to a debridement or transmetatarsal amputation optimizes chances for functional recovery. The NanoCross Elite .014-inch OTW PTA balloon catheter is a specialty niche balloon for us, given its tapered 0.5 mm sizing, long length, and ease of use across the pedal arch. The 2.0(proximal)/1.5(distal) x 210 mm and 2.5(proximal)/2.0(distal) x 210 mm (Figure 5) are workhorse pedal balloons in our lab. 

 

This article is supported by Medtronic.

 

*Images courtesy of Dr. Paul Michael. Individual results may vary.

Disclosure: Dr. Michael reports he is a consultant to Abbott, Asahi Intecc, Boston Scientific, Medtronic, Philips, and Terumo.

Dr. Paul Michael can be contacted at drpaulmichael@gmail.com or on Twitter @drsavealimb.

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BEHIND THE SCENES

Talking With the Operator

Cath Lab Digest talks with Paul Michael, MD, Medical Director, Wound Management & Limb Preservation Center, JFK Medical Center, Palm Beach, Florida.

Can you tell us about your center?

I am medical director at the Wound Management & Limb Preservation Center at JFK Medical Center. We focus on all aspects of wound management and have been operational under this name for over a year. Our center has created a team of subspecialties (including foot and ankle surgery, plastic surgery, vascular surgery, interventional cardiology, infectious disease, endocrinology, vascular medicine, and dermatology) in order to create synergistic, total body wound care. By having a cardiovascular disease specialist working more deeply with the wound management team, we were able to create a more patient-centric approach to wound healing and limb preservation. We focus on achieving accelerated wound healing results through management of the underlying disease process, as well as providing advanced interventional solutions in our CLI patients. What makes us different and unique is that we assess all patient needs, everything from psychiatry to podiatry, and arteries to veins, and all at the same time.

Can you describe your patient population?

We have a multi-ethnic patient population, with many African American, Puerto Rican, Cuban, Afro-Caribbean, and Caucasian patients. Within our overall patient population, there is a group with extremely advanced hypertensive diseases. Our Afro-Caribbean population is very interesting and difficult to manage because of their advanced risk factors, mainly hypertension and diabetes. We have a large amount of CLI in our area.

Can you take us through what happens when a patient comes to the center?

Ninety-nine percent of the diagnosis is made in the initial visit with a visual assessment of the wound and a basic assessment of perfusion. In what we call the “pathway to angiography,” patients routinely go from handheld Doppler straight to angiography. We have an extensive intake for wound patients with a standard protocol for photograph analysis of the wound. It also allows for the documentation of wound closure progression, done with graphical analysis and an advanced EHR system called WoundExpert. After the visual assessment of the wound takes place, a perfusion assessment is done with a handheld Doppler. If an ankle-brachial index (ABI) is necessary, it is done immediately. The handheld Doppler is used to reconstruct the presence or the absence of the tibial arteries and the pedal loop. We proceed within an algorithm depending on the assessment with the handheld Doppler. If it is inconclusive and good pulses exist, we will get a duplex, but most of the time, wound patients with compromised flow will go straight to an angiogram. We also do a physical exam assessment for venous disease so that any venous disease can be addressed at the same time. If a wound is present and the patient has not yet been established with a podiatrist, then we immediately arrange for them to see the foot and ankle specialist. All of the consults are coordinated and then patients start their care pathway.

Can you describe more of your work as an interventionalist from a revascularization perspective?

We do everything the patient needs to get the job done. We perform wound-directed therapy, but are also very aggressive in pedal reconstruction. Patients should have as complete a revascularization as possible for advanced wound management. We have the tools for that, which can be seen in our wound healing rates. We have over 98% success in limb salvage (obviously there is selection bias there) and a 99% success rate with chronic total occlusions. At a fundamental level, my revascularization algorithm begins with selecting the best strategy to provide inline and pressurized flow to the wound. This begins with the CLI diagnostic angiogram when possible, followed by an access strategy that maximizes successful crossing and revascularization.

How are patients typically referred to your center?

Our patients come from all over, including primary care, podiatry, and vascular surgery. When our center first launched, we spread the word in our physician community by giving talks to wound specialists — specifically, to foot and ankle surgeons that care for and are motivated regarding wounds, because there are many practices where wound patients kind of become a “nuisance” in a busy podiatry office. These patients really need specialized attention and that is best done at a wound management site with a focus on CLI. Our willingness to take over care for these patients encouraged buy-in from primary care, podiatry, and vascular surgeons, who can now refer these patients to our center, and remain confident that care is extended and patients remain part of their practice.

What do you see as the current state of CLI care?

We have a major need for better tools and better training. Becoming more and more advanced with technology will not do us any good, unless we can actually train physicians, staff, and industry personnel how to use these concepts in the wider community to benefit patients. Just like there are “access to care” issues, with CLI, there are “access to skill” issues. We need more education, and along with that, comes more awareness of the disease process. The goal is to simplify and standardize CLI care. It may involve adopting new technology, treating more patients, or taking the time to do a more complete job. I applaud companies like Medtronic for supporting training programs through our Wound Management & Limb Preservation Center, where operators, staff, and industry can experience a 360-degree care experience, from screening to salvage.

Any final thoughts?

We are in the wound closing business — the end goal is healing the wound and allowing patients to return to function. If that is the goal, and you are always striving to find the best way to avoid amputation, it will always lead you in the right direction. Tibial-pedal reconstruction with advanced wound management is the way to go. For me it began at AMP, where many more operators will also get their start. Anyone willing and motivated enough to put work into limb salvage will be greeted by grateful patients who know you chose their life over amputation.

UC20202002481 EN © 2019 Medtronic. All brands are trademarks of their respective owners.

References
  1. Gerhard-Herman MD, Gornik HL, Barrett C, et al. 2016 AHA/ACC guideline on the management of patients with lower extremity peripheral artery disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2017 Mar 21;135(12):e726-e779.
  2. Nehler MR, Duval S, Diao L, et al. Epidemiology of peripheral arterial disease and critical limb ischemia in an insured national population. J Vasc Surg. 2014 Sep;60(3):686-95.e2.
  3. Saab F, Jaff MR, Diaz-Sandoval LJ, et al. Chronic total occlusion crossing approach based on plaque cap morphology: the CTOP classification. J Endovasc Ther. 2018 Jun; 25(3): 284-291.
  4. McKinsey JF, Zeller T, Rocha-Singh KJ, et al; DEFINITIVE LE Investigators. Lower extremity revascularization using directional atherectomy: 12-month prospective results of the DEFINITIVE LE study. JACC Cardiovasc Interv. 2014 Aug; 7(8): 923-933.
  5. Rastan A, McKinsey JF, Garcia LA, et al; DEFINITIVE LE Investigators. One-year outcomes following directional atherectomy of infrapopliteal artery lesions: subgroup results of the prospective, multicenter DEFINITIVE LE trial. J Endovasc Ther. 2015 Dec; 22(6): 839-846.
  6. Reijnen MMPJ, van Wijck I, Zeller T, et al. Outcomes after drug-coated balloon treatment of femoropopliteal lesions in patients with critical limb ischemia: a post hoc analysis from the IN.PACT Global Study. J Endovasc Ther. 2019 Jun; 26(3): 305-315.
  7. Speck U, Cremers B, Kelsch B, et al. Do pharmacokinetics explain persistent restenosis inhibition by a single dose of paclitaxel? Circ Cardiovasc Interv. 2012;5:392-400.

For United States Audiences Only

HawkOne Directional Atherectomy System

The HawkOne peripheral directional atherectomy system is intended for use in atherectomy of the peripheral vasculature. The HawkOne catheter is indicated for use in conjunction with the SpiderFX embolic protection device in the treatment of severely calcified lesions. The HawkOne catheter is not intended for use in the coronary, carotid, iliac or renal vasculature.

TurboHawk Plaque Excision System

The TurboHawk peripheral plaque excision system is intended for use in the atherectomy of the peripheral vasculature. The TurboHawk catheter is NOT intended for use in the coronary, carotid, iliac, or renal vasculature. The TurboHawk catheter is indicated for use in conjunction with the SpiderFX embolic protection device in the treatment of severely calcified lesions  (LS-C and LX-C only).

Medtronic directional atherectomy products are contraindicated for use in patients with in-stent restenosis.

Chocolate PTA balloon catheter

The Chocolate PTA balloon catheter is intended for balloon dilatation of lesions in the peripheral vasculature, including the iliac, femoral, ilio-femoral, popliteal, infra-popliteal, and renal arteries.

IN.PACT Admiral Drug Coated PTA Balloon Catheter Brief Statement (For USA only)

FTSOP113326-32 Rev. 1G

Indications for Use:

The IN.PACT Admiral paclitaxel-coated PTA Balloon Catheter is indicated for percutaneous transluminal angioplasty, after appropriate vessel preparation, of de novo, restenotic, or in-stent restenotic lesions with lengths up to 360 mm in superficial femoral or popliteal arteries with reference vessel diameters of 4-7 mm.

Contraindications

• The IN.PACT Admiral DCB is contraindicated for use in:

• Coronary arteries, renal arteries, and supra-aortic/cerebrovascular arteries

• Patients who cannot receive recommended antiplatelet and/or anticoagulant therapy

• Patients judged to have a lesion that prevents complete inflation of an angioplasty balloon or proper placement of the delivery system

• Patients with known allergies or sensitivities to paclitaxel

• Women who are breastfeeding, pregnant or are intending to become pregnant or men intending to father children. It is unknown whether paclitaxel will be excreted in human milk and whether there is a potential for adverse reaction in nursing infants from paclitaxel exposure.

Warnings

• Use the product prior to the Use-by Date specified on the package.

• Contents are supplied sterile. Do not use the product if the inner packaging is damaged or opened.

• Do not use air or any gaseous medium to inflate the balloon. Use only the recommended inflation medium (equal parts contrast medium and saline solution).

• Do not move the guidewire during inflation of the IN.PACT Admiral DCB.

• Do not exceed the rated burst pressure (RBP). The RBP is 14 atm (1419 kPa) for all balloons except the 200 and 250 mm balloons. For the 200 and 250 mm balloons the RBP is 11 atm (1115 kPa). The RBP is based on the results of in vitro testing. Use of pressures higher than RBP may result in a ruptured balloon with possible intimal damage and dissection.

• The safety and effectiveness of using multiple IN.PACT Admiral DCBs with a total drug dosage exceeding 34,854 μg of paclitaxel in a patient has not been clinically evaluated.

Precautions

• This product should only be used by physicians trained in percutaneous transluminal angioplasty (PTA).

• This product is designed for single patient use only. Do not reuse, reprocess, or resterilize this product. Reuse, reprocessing, or resterilization may compromise the structural integrity of the device and/or create a risk of contamination of the device, which could result in patient injury, illness, or death.

• Assess risks and benefits before treating patients with a history of severe reaction to contrast agents.

• The safety and effectiveness of the IN.PACT Admiral DCB used in conjunction with other drug-eluting stents or drug-coated balloons in the same procedure or following treatment failure has not been evaluated.

• The extent of the patient’s exposure to the drug coating is directly related to the number of balloons used. Refer to the Instructions for Use (IFU) for details regarding the use of multiple balloons and paclitaxel content.

• The use of this product carries the risks associated with percutaneous transluminal angioplasty, including thrombosis, vascular complications, and/or bleeding events.

• Vessel preparation using only pre-dilatation was studied in the clinical study. Other methods of vessel preparation, such as atherectomy, have not been studied clinically with IN.PACT Admiral DCB.

• This product is not intended for the expansion or delivery of a stent.

Potential Adverse Effects

• The potential adverse effects (e.g. complications) associated with the use of the device are: abrupt vessel closure; access site pain; allergic reaction to contrast medium, antiplatelet therapy, or catheter system components (materials, drugs, and excipients); amputation/loss of limb; arrhythmias; arterial aneurysm; arterial thrombosis; arteriovenous (AV) fistula; death; dissection; embolization; fever; hematoma; hemorrhage; hypotension/hypertension; inflammation; ischemia or infarction of tissue/organ; local infection at access site; local or distal embolic events; perforation or rupture of the artery; pseudoaneurysm; renal insufficiency or failure; restenosis of the dilated artery; sepsis or systemic infection; shock; stroke; systemic embolization; vessel spasms or recoil; vessel trauma which requires surgical repair.

• Potential complications of peripheral balloon catheterization include, but are not limited to the following: balloon rupture; detachment of a component of the balloon and/or catheter system; failure of the balloon to perform as intended; failure to cross the lesion.

• Although systemic effects are not anticipated, potential adverse events that may be unique to the paclitaxel drug coating include, but are not limited to: allergic/ immunologic reaction; alopecia; anemia; gastrointestinal symptom s; hematologic dyscrasia (including leucopenia, neutropenia, thrombocytopenia); hepatic enzyme changes; histologic changes in vessel wall, including inflammation, cellular damage, or necrosis; myalgia/arthralgia; myelosuppression; peripheral neuropathy.

• Refer to the Physician’s Desk Reference for more information on the potential adverse effects observed with paclitaxel. There may be other potential adverse effects that are unforeseen at this time.

• Please reference appropriate product Instructions for Use for a detailed list of indications, warnings, precautions and potential adverse effects. This content is available electronically at www.manuals.medtronic.com.

Trailblazer Support Catheter

Trailblazer support catheters are percutaneous, single lumen catheters designed for use In the peripheral vascular system. Trailblazer support catheters are Intended to guide and support a guide wire during access of the vasculature, allow for wire exchanges, and provide a conduit for the delivery of saline solutions or diagnostic contrast agents.

Trailblazer Angled Support Catheter

Trailblazer angled support catheters are percutaneous, single lumen catheters designed for use in the peripheral vascular system. TrailBlazer support catheters are intended to guide and support a guide wire during access of the vasculature, allow for wire exchanges and provide a conduit for the delivery of saline solutions or diagnostic contrast agents.

EverFlex Self-Expanding Peripheral Stent with Entrust Delivery System

The EverFlex self-expanding peripheral stent with Entrust delivery system is intended to improve luminal diameter in the treatment of symptomatic de-novo or restenotic lesions up to 140 mm in length in the native superficial femoral artery (SFA) and/or proximal popliteal arteries with references vessel diameters ranging from 4.5mm - 7.5mm.

Contraindications: Use of the EverFlex self-expanding peripheral stent with Entrust delivery system is contraindicated in patients with known hypersensitivity to nickel titanium; patients contraindicated for anticoagulant and/or antiplatelet therapy; patients who have a lesion that prevents complete inflation of an angioplasty balloon or proper placement of the stent or stent delivery system. The EverFlex self-expanding peripheral stent with Entrust delivery system is contraindicated for use in the carotid artery.

Potential Adverse Events: Potential adverse events which may be associated with the use of a stent in the SFA and proximal popliteal arteries include, but are not limited to: allergic reaction, amputation, artery perforation, or rupture, bleeding requiring transfusion, Infection, pseudoaneurysm, restenosis, stent collapse or fracture, stent migration, surgical or endovascular intervention, thrombosis/occlusion of the stent.

SpiderFX Embolic Protection Device Lower Extremity (LE) Interventions

The SpiderFX embolic protection device is indicated for use as a guidewire and embolic protection system to contain and remove embolic material In conjunction with the TurboHawk peripheral plaque excision system, either during standalone procedures or together with PTA and/or stenting, in the treatment of severely calcified lesions in arteries of the lower extremities. The vessel diameter at the filter basket placement site should be between 3.0 mm and 6.0 mm.

The Pacific Xtreme PTA balloon dilatation catheter

The Pacific Xtreme PTA balloon dilatation catheter in 150 mm, 200 mm, 250 mm and 300 mm balloon length is intended to dilate stenoses in femoral, popliteal and infrapopliteal arteries.

The Pacific Plus PTA balloon catheter

The Pacific Plus PTA balloon catheter is intended to dilate stenoses in the iliac, femoral, iliofemoral, popliteal, infrapopliteal and renal arteries; and for the treatment of obstructive lesions of native or synthetic arteriovenous dialysis fistulae.

The NanoCross Elite 0.014” OTW PTA balloon dilatation

The NanoCross Elite 0.014” OTW PTA balloon dilatation catheter is intended to dilate stenoses in the iliac, femoral, ilio-femoral, popliteal, infra-popliteal, and renal arteries, and for the treatment of obstructive lesions of native or synthetic arteriovenous dialysis fistulae. This device is also indicated for stent post-dilatation in the peripheral vasculature.

CAUTION: Federal (USA) law restricts these devices to sale by or on the order of a physician.

IMPORTANT: Indications, contraindications, warnings, and instructions for use can be found in the product labeling supplied with each device.

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