Current estimates suggest that peripheral arterial disease (PAD) may already affect up to 200 million people worldwide and approximately 8.5 million people in United States alone.1,2 The nationwide epidemic of diabetes and renal failure, age, hypertension, hyperlipidemia, and smoking have become the definitive risk factors in identifying these patients. Many patients with PAD have arteries affected below the knee, and now, with longer length catheters and wires, we are seeing and regularly treating vessels below the ankle as well. However, there is limited data published3 regarding the effectiveness of atherectomy below the knee or ankle.
The DEFINITIVE LE study (Determination of effectiveness of the SilverHawk PerIpheral Plaque Excision System (SilverHawk Device) for the Treatment of Infrainguinal Vessels/Lower Extremities) demonstrated a safe and effective technique providing high one-year patency rates (89.6%) in claudicant patients with infra-popliteal artery lesions treated with directional atherectomy.4 In the critical limb ischemia (CLI) cohort of DEFINITIVE LE, the primary endpoint was freedom from major unplanned amputation of the target limb at 12 months, with a rate of 95%.3 Treatment of the pedal loop is paramount in achieving a successful revascularization in CLI and claudicants, and will achieve the greatest long-term patency and the optimal benefit in avoiding partial limb amputation.5 We present a case demonstrating use of directional atherectomy technology below the ankle for revascularization of the pedal loop to demonstrate that atherectomy + PTA may be more beneficial to PTA alone in maximizing patient outcomes.
Case Report
A 52-year-old nondiabetic female was evaluated for severe short distance claudication, lower extremity cramping, plantar surface neuropathy, toe color changes, cold feet and toes, poor pedal pulses, and chronic lower extremity throbbing pain and fatigue at rest (Rutherford class IV). Ultrasounds revealed multiple elevated arterial velocities in both legs, worse on the left. Lower extremity arteriograms were warranted for further endovascular evaluation. The left leg was addressed via antegrade approach due to a maximum usable catheter length of 132 cm. The distal left posterior tibial artery and lateral plantar artery demonstrated slower TIMI-I flow, with a diffusely narrowed lateral plantar artery and poor pedal loop representation. Delayed flow down the anterior tibial artery demonstrated mild to moderate narrowing of the distal anterior tibial artery and dorsal pedis artery (Figure 1). The revascularization procedure across the posterior tibial, lateral plantar, dorsal pedis, and anterior tibial arteries was performed successfully over a Gladius .014-inch wire (Asahi Intecc) without complications. The predilatation procedure at the pedal loop was performed from the lateral plantar approach by first positioning a 2.0 x 120 mm NanoCross Elite .014-inch OTW PTA balloon catheter (Medtronic) across the lateral plantar artery with the arc of the balloon in the middle of the pedal arterial loop. The distal aspect of the balloon was positioned in the dorsal pedis artery and the proximal aspect in the lateral plantar artery.
After the tract was predilated, the SilverHawk DS low-profile distal small vessel atherectomy catheter was advanced across the pedal loop once with blade closed for an initial “dry run” to see if the catheter would advance across the tract without significant resistance. The DS catheter can effectively treat a 1.5-2.0 mm artery diameter. This initial dry run (blade closed) was successful and the atherectomy device was advanced across the tract 3 times with the blade open, with the tip terminating at the distal anterior tibial artery with each pass (Figure 2). Directional atherectomy was followed by percutaneous transluminal angioplasty (PTA) of the pedal loop using a 2.0 x 120 mm NanoCross Elite PTA balloon inflated for 90-seconds at 8 atmospheres of pressure in the anterior tibial/dorsal pedis arteries, followed by the pedal loop, and then the distal posterior tibial/lateral plantar arteries. Nitroglycerine 200 mcg was injected into the area through the balloon catheter to further medically dilate the vessel, and a gentle injection through the balloon catheter tip demonstrated a widely patent, now symmetrically dilated tract, with a restored pedal loop perfusing the dorsal surface tissues, the metatarsal regions and toes, and the plantar surface tissues with excellent overall perfusion and rapid washout. Final angiography demonstrated successful post-treatment results and much improved arterial perfusion into the left foot across a now clearly patent and dilated pedal arterial loop (Figure 4). One week post procedure, patient indicated presenting symptoms were markedly improved, with noted improvement in toe color and skin temperature.
Discussion
As we continue to treat lower extremity PAD, chronic total occlusions, and CLI patients more distally, we must continue to explore the capabilities of available devices. In this case, we chose to test the efficacy of the SilverHawk DS atherectomy device beyond its typical distal reach and function, and advance further across the pedal loop and distal arterial vessels of the feet. The SilverHawk, TurboHawk, and HawkOne directional atherectomy devices (Medtronic) have proven to be versatile and effective in treating challenging atherosclerosis with resistive calcified plaque in most of the arteries of the lower extremities.7 The SilverHawk DS device proved to be just as effective in removing plaque in the pedal loop compared to its use in the more proximal vessels, given a cooperative vascular setting. This case demonstrates a successful clinical outcome using existing directional atherectomy technology across the distal plantar and pedal loop arteries. 
This article is supported by Medtronic.
*Images courtesy of Charles Jost, MD, and Kirk Minkus, MD. Individual results may vary.
Disclosures: The authors report no conflicts of interest regarding the content herein.
The authors can be contacted through their office: Southwest Cardiovascular Associates, Mesa, Arizona
480-945-4343 | [email protected]
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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).
SILVERHAWK™ Plaque Excision System
The SilverHawk™ Peripheral Plaque Excision System is intended for use in atherectomy of the peripheral vasculature. The catheter is NOT intended for use in the coronary, carotid, iliac or renal vasculature.
Medtronic directional atherectomy products are contraindicated for use in patients with in-stent restenosis.
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 Information: Indications, contraindications, warnings and instructions for use can be found in the product labeling supplied with each device.
UC202010176 EN © 2020 Medtronic
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- Fowkes FG, Rudan D, Rudan I, et al. Comparison of global estimates of prevalence and risk factors for peripheral artery disease in 2000 and 2010: a systematic review and analysis. Lancet. 2013;382:1329–1340.
- Peripheral arterial disease (PAD). National Center for Chronic Disease Prevention and Health Promotion, Division for Heart Disease and Stroke Prevention. December 19, 2019. Available online at https://www.cdc.gov/heartdisease/PAD.htm. Accessed January 28, 2020.
- 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.
- 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.
- Adams GL, Smith I, Subramanian V. Case study: endovascular reconstruction of the pedal loop; illustrating challenges and strategy. CLI Global. June 2017; 14-16. Available for download at https://cliglobalsociety.org/resources/Compendium/2017/CLIG_0617.pdf. Accessed January 28, 2020.
- Ali M, Zaghlou H, El Mahdy H. Below-the-ankle angioplasty: early and mid-term outcome. The Egyptian Journal of Surgery. 2018 Feb 25; 37: 526-532. Available online at http://www.ejs.eg.net/article.asp?issn=1110-1121;year=2018;volume=37;issue=4;spage=526;epage=532;aulast=Ali. Accessed January 28, 2020.
- Michael P. Take charge of CLI: tools for optimal CLI revascularization. Cath Lab Digest. 2019 Aug; 27(8): 1, 12-15. Available online at https://www.cathlabdigest.com/content/take-charge-cli-tools-optimal-cli-revascularization. Accessed January 28, 2020.