Revascularization of Calcified Infrapopliteal Chronic Total Occlusion

ABSTRACT: Infrapopliteal chronic total occlusion (CTO) lesions remain to be technically challenging for endovascular therapy. The complexity of intervention demands access, techniques, and devices for revascularization that are uncommon. This case report presents a patient with calcified infrapopliteal CTO with critical limb ischemia that was successfully crossed using a CTO catheter.

VASCULAR DISEASE MANAGEMENT 2013:10(3):E56-E58

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Case Report

An 82-year-old male with history of hypertension, dyslipidemia, and chronic venous insufficiency presented with a nonhealing right heel ulcer and critical limb ischemia (CLI). Physical examination was unremarkable except for a well-demarcated 1-cm erythematous ulceration at the right heel without drainage and mild tenderness on palpation. Pedal pulses were nonpalpable in the right foot, but the dorsalis pedis pulse was present on Doppler. Ankle Brachial Index (ABI) measurement revealed an abnormal result of 0.65 in the right lower extremity compared to 0.95 in the left.  Subsequent diagnostic peripheral angiography confirmed a severely diseased anterior tibial (AT) artery with distal tibioperoneal trunk  (TPT) 100%occlusion (Figure 1) with faint reconstitution of the peroneal and posterior tibial (PT) arteries via collaterals.

In the setting of CLI with a nonhealing ulcer in the corresponding angiosome, an endovascular intervention of the right TPT occlusion was pursued. A TruePath CTO Device catheter (Boston Scientific) was advanced across the occlusion into the distal peroneal artery (Figure 2). Subsequent angiogram confirmed intraluminal position of the distal wire in the peroneal artery (Figure 3). 

A second wire was then advanced into the PT artery and balloon angioplasty performed of the PT and peroneal arteries using a Coyote 2 x 220 mm balloon (Boston Scientific) with good angiographic result and brisk 2-vessel runoff into the right foot (Figure 4). The patient was discharged home the following day and returned for follow-up in 4 weeks with no residual symptoms, a completely healed ulcer, and improved ABI of 1.34.

Discussion

Peripheral arterial disease (PAD) affects an estimated 8 million to 12 million Americans.¹ Advancing age, diabetes, and kidney disease increase the risk of intra-arterial calcification and PAD.² Intra-arterial calcium distribution has been observed to be disproportionate, with only 10% suprainguinal and 90% infrainguinal; and 75% of the infrainguinal calcium resides in the infrapopliteal vessels.³ Patients with CLI typically present anatomically with infrapopliteal calcific CTOs.  Revascularization of CTOs, specifically infrapopliteal lesions, requires use of uncommon access, techniques, and devices for successful crossing and recanalization.²

The TruePath CTO catheter is a low-profile (0.018 inch) crossing device designed to penetrate fibrocalcific CTOs.⁴ This device is advanced as a wire to the proximal cap of the CTO through a support catheter. The diamond-coated tip is then activated and rotates at 13,000 rpm through the occlusion cap. The nitinol outer shaft tapers over the distal 9-cm tip of the catheter to allow optimal shaping and flexibility as it traverses the occlusion. The signal conveyed by the hand-held device console differentiates contact of the tip with fibrocalcified plaque versus elastic tissue to avoid subintimal entry and to maintain intraluminal position. Once across the CTO, the support catheter is advanced and the TruePath catheter exchanged for an interventional wire for additional therapy. Moreover, the small profile of the device allows its use via alternative access such as transpedal or tibial artery entry for retrograde crossing.  

The ReOpen study was conducted to evaluate the safety and efficacy of the TruePath CTO catheter to facilitate crossing of infrainguinal CTO.⁵ Inclusion criteria were single occlusions less than 30 cm in length, occlusion more than 30 days old, reference vessel diameter larger than 2 mm, and concurrent failure of guidewire to cross the lesion. Enrolled patients underwent attempted crossing of CTO with the TruePath device followed by angioplasty and/or stenting. Follow-up post procedure involved 30-day clinical evaluation with ABI measurements. A total of 85 patients were enrolled with predominantly SFA lesions (72%), moderate (41%) or severe (38%) calcification, reference vessel diameter of 5.4 mm, and mean lesion length of 166.5 mm.  Average TruePath activation time was 8.2 minutes and average fluoroscopy time was 24 minutes. Technical success with the TruePath catheter was achieved in 80%, with freedom from clinical perforation in 99% and improved mean ABI from 0.65 to 1.00 at 30 days.  

Although the ReOpen study only included 13% infrapopliteal CTOs, the case presented herein demonstrates the utility of the TruePath CTO catheter for revascularization of below-the-knee CTOs.

References

1. Hirsch AT, Criqui MH, Treat-Jacobson D, et al. Peripheral arterial disease detection, awareness, and treatment in primary care. JAMA. 2001;286(11):1317-1324.
2. Adams GL, Gardner SJ, Gardner J, et al. Exotic access, techniques, and devices for infrapopliteal CTOs: recommendations on how to successfully cross chronic total occlusions of the infrapopliteal vasculature. Endovasc Today. 2012;May:44-49.
3. Bishop PD, Feiten LE, Ouriel K, et al. Arterial calcification increases in distal arteries in patients with peripheral arterial disease. Ann Vasc Surg. 2008;22(6):799-805.
4. Boston Scientific. TruePath CTO Device instructions for use. https://www.bostonscientific.com/truepath/device.html. 
5. Boston Scientific. TruePath CTO Device ReOpen Study data. https://www.bostonscientific.com/truepath/clinical-data.html.

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Editor’s Note: Disclosure: The author has completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr. George reports consultancy to Boston Scientific.  

Manuscript received January 14, 2013; final version accepted January 31, 2013.

Address for correspondence: Jon C. George, MD, Director of Clinical Research, Division of Cardiovascular Medicine, Deborah Heart and Lung Center, 200 Trenton Road, Browns Mills, NJ, 08015, USA. Email: georgej@deborah.org