Disclosure: Dr. Ravish Sachar reports he is on a medical advisory board for Abbott, and conducts educational symposia for Covidien.

Dr. Ravish Sachar can be contacted via email at rsachar@gmail.com.

History

A 64-year-old female patient presented complaining of left calf claudication after walking approximately 50 feet. She also reported pain in her left toes at night, which improved when she got out of bed or dangled her feet off the side of the bed. Her past medical history was significant for diabetes mellitus, coronary artery disease and coronary artery bypass grafting, hypertension, and dyslipidemia. She had a normal left ventricular ejection fraction and normal renal function. On exam, she did not have any evidence of tissue loss or ulceration on her left foot, but her toes were cool and erythematous. Her pedal pulses were absent bilaterally. She underwent a lower extremity arterial duplex in the office that revealed a left ankle-brachial index (ABI) of 0.47 and a right ABI of 0.64. Duplex images were consistent with a high grade left popliteal stenosis. 

Her symptoms were felt to be consistent with critical limb ischemia, and a decision was made to proceed with lower extremity angiography. 

Procedure

The patient was brought to the cardiac catheterization lab, and vascular access was obtained in the right common femoral artery using the modified Seldinger technique. A 5 French short sheath was inserted over a Wholey Wire (Covidien). An Omni Flush catheter (AngioDynamics, Inc.) was advanced into the abdominal aorta, and angiography was performed followed by lower extremity run-off under digital subtraction angiography. This showed that the left common iliac, external iliac, common femoral, profunda femoris, and superficial femoral arteries were free of obstructive disease (Figure 1a). The left popliteal artery had severe, diffuse, irregular disease involving the proximal, mid, and distal segments, resulting in 90-99% diameter stenosis (Figure 1b).  There was single vessel run-off to the left leg via the posterior tibial artery (Figure 1c). The length of the lesion in the popliteal artery was approximately 80mm. 

Due to the patient’s symptoms, a decision was made to proceed with revascularization of the left popliteal artery. The location of the stenosis was not ideal for stenting and, therefore, the lesion was treated with directional atherectomy. The lesion was crossed with a 0.035-inch stiff-angled Glidewire (Terumo), using a 4 French (Fr) 135cm Navicross catheter (Terumo) for support.  After the lesion was crossed successfully, the Navicross catheter was advanced across the lesion and selective angiography was performed to confirm intraluminal position. This also confirmed single vessel run-off to the left foot via a patent posterior tibial artery.  A long Grand Slam wire (Asashi Intecc/Abbott Vascular) was advanced into the distal posterior tibial artery, and was then used to position a 3mm SpiderFX embolic protection device (Covidien) in the mid portion of the posterior tibial artery (Figure 2). 

It was felt that the lesion severity would preclude passage of the atherectomy catheter, and therefore, the lesion was treated with percutaneous transluminal angioplasty (PTA) using a 2.0/80 Nanocross balloon (Covidien) inflated at 6 atmospheres for 60 seconds (Figure 3). Following this, directional atherectomy of the diseased segment was performed (Figure 4) using a TurboHawk LX-M device (Covidien).  All four quadrants were treated, and repeat angiography was performed. The medial and lateral segments were each treated with one more pass of the device. Angiographic results were improved, but remained suboptimal. PTA was therefore performed with a 4.0 x 80mm Nanocross balloon, which was inflated at 2 atmospheres for 60 seconds (Figure 5). This resulted in a reduction of diameter stenosis to approximately 20% (Figure 6). The SpiderFX was removed, and debris was noted in the SpiderFX. The posterior tibial artery remained patent, and there was no evidence of distal embolization. 

The patient had an uncomplicated post-procedural course and was discharged home the same day. She had complete resolution of her left leg claudication and rest pain.  A follow-up duplex done at 3 months did not show any evidence of significant restenosis. Approximately 7 months after the procedure, she returned for angiography and revascularization of the right lower extremity. Left leg angiography was performed at that time and showed a widely patent left popliteal artery (Figure 7).

Discussion

Lesions in the common femoral and popliteal are challenging to treat. PTA alone has been shown in several studies to be inferior to stenting in terms of long-term patency.^1-7 Furthermore, PTA may result in flow-limiting dissections, necessitating the need for bailout stenting. While angioplasty with newer scoring balloons may reduce the risk of dissection, it is not clear that this translates to an improvement in long-term patency as compared to PTA with traditional balloons. Stent placement in these vascular beds, primary or bailout, is not ideal due to a concern for increased risk of stent fracture in these segments. Thus, directional atherectomy represents a good option in these vascular beds. 

The recently published DEFINITIVE LE study provides us with data to support the use of directional atherectomy for these lesions.⁸ This non-randomized, prospective trial enrolled 800 patients in 47 centers who were further subcategorized into two arms, those with claudication (n=598, Rutherford 1-3) and those with critical limb ischemia (n=201, Rutherford 4-6). Among those with claudication, the 12-month primary patency, as defined by a peak systolic velocity ratio of ≤2.4 with no clinically-driven target lesion revascularization in the treated segment, was 78% for a mean lesion length of 7.5 cm. The 12-month patency in popliteal vessels (n=114) was 77%. Notably, a pre-specified subset analysis showed no significant difference in 12-month patency between diabetic and non-diabetic claudicants. Among those with critical limb ischemia, the mean lesion length was 7.2 cm and freedom from major amputation and wound-healing rates at 12 months were 95% and 72%, respectively. 

For many years, we have had a paucity of data to guide our decisions in the treatment of peripheral vascular disease. More recently, however, a number of studies have increased our knowledge base.^9-12 As we synthesize these data and incorporate them into our daily practice, it is important to understand what we know, and where we still have insufficient data. These recent data suggest that when treating femoro-popliteal disease with bare-metal stents, drug-eluting stents, and drug-coated balloons, we should expect 12-month patency rates ranging from 75%-85% for mean lesion lengths in the 70-90mm range.^9-12 The DEFINITIVE LE trial adds to our growing knowledge base and gives us confidence that we can expect similar outcomes for our patients when treated with directional atherectomy. 

References

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7. Ansel G.M., LINC 2010
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12. Tepe G. IN.PACT SFA: randomized trial of IN.PACT Admiral DCB vs. PTA for the treatment of atherosclerotic lesions in the SFA and/or PPA. Presented at: Charing Cross International Symposium. April 5, 2014. London, United Kingdom.