Stenting the Popliteal Artery

Interview with Erik G. Stilp, MD, FACC, RPVI, Ascension – Columbia St. Mary’s, Milwaukee, Wisconsin.

This article was originally published in Cath Lab Digest, Volume 27 - Issue 9 - September 2019.

Can you tell us about your practice?

I am an interventional cardiologist practicing in Milwaukee, Wisconsin, at the tertiary care hospital for a large, statewide medical system. My practice involves all types of interventional coronary and peripheral vascular care, although we focus on the treatment of critical lower limb ischemia (CLI), both patients with resting pain due to arterial insufficiency or non-healing wounds. We have a large wound care center, and a strong collaboration with podiatry, cardiovascular surgery, internal medicine, and wound care specialists to limit amputation as much as possible. We do a fairly large volume of non-lower extremity arterial procedures as well, including aneurysms, renal artery intervention, carotid artery intervention, and aortic intervention. I would say 80% of our practice is non-coronary disease, but our group’s cardiovascular practice is large and subspecialized. Those partners who don’t treat peripheral artery disease (PAD) will send their general cardiology patients with peripheral disease to us. We have a large referral base with podiatry and wound care, and a significant number of primary care, nephrology, and endocrinology referrals as well. We will collaborate with cardiothoracic and vascular surgery, both in hybrid settings and in situations where open surgery is not the best option for patients.

What challenges do you face in treating PAD?

Lower-extremity PAD is an incredibly comorbid disease state, especially in patients with critical limb ischemia. Before even intervening, there are a number of challenges in dealing with comorbidities such as renal insufficiency, uncontrolled diabetes, concurrent coronary or non-coronary heart disease, and cerebrovascular disease.

Disease states often need to be better controlled medically prior to intervention, and some bring complications or barriers to successful intervention. Changing lifestyles is a challenge. Many patients with PAD must make lifestyle modifications in order to better control their disease state, and getting people to quit smoking and take medications can be a challenge. In regard to procedural challenges, calcium, chronic total occlusions, tibial disease, across-joint disease, and lasting patency are all of concern. We are skilled at opening arteries a first, second, and even a third time, but we would rather not have to do it more than once, and if we must do it more than once, we would like to minimize reintervention as much as possible. Providing lasting results for patients without the need for reintervention is challenging.

What are difficulties specific to maintaining patency in the popliteal artery?

Any area that is under repetitive flexion or force is not only a likely place for native vessel disease, but will be a challenge to keep open after intervening, be it with scaffold or non-scaffold options. It is difficult to maintain patency in flexion spaces over the long run, something that is true for both endovascular therapy and surgical interventions. Certainly, bypasses that cross joint lines have been proven to have lower patency than those that don’t cross joint lines. The problem is finding a therapy that withstands the repetitive force and flexion of the popliteal artery.

How do you approach complex lesions in the popliteal artery?

Given the August 7th FDA letter regarding paclitaxel-coated devices, which had become a favored therapy for the popliteal artery, the algorithm is changing at my institution. For now, it’s important to have a variety of therapies which have demonstrated positive patient outcomes. Angioplasty alone or atherectomy combined with angioplasty are often utilized. If we stent, we want to use a scaffold that is at least indicated, has been clinically studied, and demonstrates improved patency in comparison to angioplasty alone.

I don’t hesitate to stent what we call the P1 segment of the popliteal or that transition zone between the distal superficial femoral artery (SFA) and the above-knee popliteal artery. Once you encroach upon the patella and then certainly across the joint line, it is important to evaluate all options, as well as to make sure that the patient is quite able to tolerate dual antiplatelet therapy, potentially indefinitely, so an across-knee or full popliteal intervention will stay open. I hesitate to stent in the P2 and P3 segments of the popliteal, but the LifeStent Vascular Stent System (BD) is a nice option in those places, based off the level 1, rigorous ETAP trial data¹ (Endovascular Treatment of Atherosclerotic Popliteal Artery Lesions: balloon angioplasty vs. primary stenting) and the fact that LifeStent is the only stent with a FDA indication for the full popliteal artery. It’s hard to argue against double the primary patency rate at 2 years compared to plain old balloon angioplasty (POBA).¹

Can you describe a recent complex popliteal case and its outcome?

A recent complex case involved a 63-year-old male heavy smoker that had no perioperative vascular workup surrounding prior 5th toe amputations bilaterally. He was referred due to a non-healing left 4th toe ulceration and had long-standing bilateral short-distance calf claudication. His ankle-brachial index (ABI) was 0.65 at rest on the left with easily palpable bilateral femoral pulses.

Via right femoral puncture, left leg angiography identified a distal superficial femoral artery (SFA) and popliteal chronic total occlusion (CTO) with unfavorable proximal cap morphology, P2 popliteal reconstitution right at the knee joint (Figure 1), and patent though diffusely diseased below-knee anatomy.

A brief antegrade attempt at CTO crossing with a 5 French (F) system, an .035-inch angled support catheter, and multiple .018-inch and .035-inch wires, failed to achieve P2 popliteal true-lumen positioning. Thus, 4F left dorsalis pedis artery access was obtained and the CTO crossed retrograde with an .018-inch support catheter and wire (Figure 2), externalizing the .018-inch wire via the antegrade support catheter to ultimately form an .014-inch wire rail.

Atherectomy and 6 mm prolonged pre-dilation resulted in extensive popliteal artery dissection; thus a 6 mm x 150 mm LifeStent 5F Vascular Stent (BD) was placed on the .014-inch wire from just above the joint line in the P2 popliteal back into Hunter’s canal (Figure 3). The stent was post-dilated with a 6 mm balloon for an excellent result and preservation of brisk 3-vessel outflow at the end of the case (Figure 4). A 5F extravascular closure device sealed the right femoral arteriotomy and external band compression was used on the left dorsalis pedis. Prompt wound healing was achieved over the subsequent weeks.

What features of the LifeStent 5F Vascular Stent do you find most important?

I think it is important to distinguish the current LifeStent 5F from the legacy LifeStent. I find the deliverability and necessary sheath size for the LifeStent 5F to be ideal. Vascular access complications are the bane of the peripheral interventionalist, and we take a lot of pride in minimizing complications. Certain vascular access complications are associated with sheath and arteriotomy size. If we can get away with a 5F intervention for what used to be a 6F or 7F intervention, we can potentially minimize some of those procedural complications. Most, if not all, other nitinol self-expanding stents on an .035-inch platform deliver very poorly on anything other than an .035-inch wire, in my opinion. The LifeStent 5F Vascular Stent has a nice crossing profile even on an .014-inch wire. We are frequently primary .014-inch wire operators, like many interventional cardiologists. If you are crossing complex lesions with .014-inch systems and then need to wire exchange for heavier wires, it can increase procedural time and fluoroscopy exposure for staff, operators, and patients, and ultimately, can decrease the number of procedures you perform. The ability to cross on an .014-inch wire and to treat from smaller sheath sizes is a big advantage. Finally, being able to stent the full popliteal artery, when needed, with an on-label option is a key benefit of the LifeStent 5F Vascular Stent. LifeStent is designed for unique vessel conformability and is the only stent indicated by the FDA for treatment of the entire popliteal artery, an indication obtained after publication of 2-year results of the ETAP trial, a Level 1, rigorous investigation into the safety and efficacy of the LifeStent in the popliteal artery.¹

How has use of the LifeStent 5F Vascular Stent changed your treatment algorithm?

To start, the LifeStent 5F has changed popliteal intervention from a routine 6F or 7F procedure to a de facto 5F procedure, which is huge at our institution. A smaller arteriotomy could mean earlier ambulation and potentially less frequent overnight stays.^2,3 It used to be that we routinely started cases with a 5F or 6F short sheath, performed diagnostic angiography, and if we found highly stenotic or occluded femoropopliteal disease, we would go straight to 7F for backup purposes, for ease of delivery of equipment, and for potential use of reentry devices and atherectomy devices. But now, with thin-walled sheaths, low-profile devices, and specifically LifeStent 5F, we have even more access and treatment options for our patients that may help reduce risk of access site complications.⁴ 

This article is supported by BD Interventional.

Disclosures: Dr. Erik Stilp reports he is a consultant/speaker for BD/ Bard, Philips, and Abbott Vascular, and has no stocks/holdings. Dr. Erik Stilp reports that he was compensated by BD Interventional for his time associated with this article.

Dr. Erik Stilp can be contacted at erik.stilp@ascension.org.

References

1. Rastan A, Krankenberg H, Baumgartner I, et al. Stent placement vs. balloon angioplasty for popliteal artery treatment: two-year results of a prospective, multicenter, randomized trial. J Endovasc Ther. 2015 Feb; 22(1): 22-27. Primary patency at 24 months: PTA=31.3% (n=94), stent=64.2% (n=89).
   Primary Patency and TLR rates calculated when provisional stenting is considered TLR. Event-free survival; a composite of freedom from death, TLR, myocardial infarction, and major or minor amputation of the target limb; was as good as or better for the LIFESTENT^® group compared to PTA through 24 months. Event-free survival was significantly longer in the stent group (605 days) than the PTA group (455 days; p<0.001) when provisional stent placement was considered a TLR. Kaplan-Meier analysis with Mantel-Cox log-rank test. The LIFESTENT^® 5F, LIFESTENT^® 5 mm and LIFESTENT^® SOLO^™ were not included in this study.
2. Mustapha JA, Saab F, McGoff T, et al. Tibio-pedal arterial minimally invasive retrograde revascularization in patients with advanced peripheral vascular disease: the TAMI technique, original case series. Catheter Cardiovasc Interv. 2014; 83(6): 987-994.
3. Levin SR, Farber A, Bertges DJ, et al. Larger sheath size for infrainguinal endovascular intervention is associated with minor but not major morbidity or mortality. Ann Vasc Surg. 2019 Jun 12. pii: S0890-5096(19)30380-2.
4. Walker CM, Mustapha J, Zeller T, et al. Tibiopedal access for crossing of infrainguinal artery occlusions: a prospective multicenter observational study. J Endovasc Ther. 2016 Dec; 23(6): 839-846.
    

The opinions and clinical experiences presented herein are for informational purposes only. The results from this case study may not be predictive for all patients. Individual results may vary depending on a variety of patient specific attributes.

LIFESTENT® 5F Vascular Stent System
Indications: The LIFESTENT® 5F Vascular Stent Systems are intended to improve luminal diameter in the treatment of symptomatic de novo or restenotic lesions up to 240 mm in length in the native superficial femoral artery (SFA) and popliteal artery with reference vessel diameters ranging from 4.0 - 6.5 mm.

Contraindications: The LIFESTENT® 5F Vascular Stent Systems are contraindicated for use in: patients with a known hypersensitivity to nitinol (nickel-titanium), and tantalum; patients who cannot receive recommended anti-platelet and/or anti-coagulation therapy; or patients who are judged to have a lesion that prevents complete inflation of an angioplasty balloon or proper placement of the stent or stent delivery system.

Warnings: The LIFESTENT® 5F Vascular Stent Systems are supplied sterile and is intended for single use only. DO NOT resterilize and/or reuse the device. DO NOT use if pouch is opened or damaged. DO NOT use the device after the “Use By” date specified on the label. Persons with allergic reactions to nitinol (nickel-titanium) alloy may suffer an allergic response to this implant. DO NOT expose the delivery system to organic solvents (e.g., alcohol). The stent is not designed for repositioning or recapturing. Stenting across a major branch could cause difficulties during future diagnostic or therapeutic procedures. If multiple stents are placed in an overlapping fashion, they should be of similar composition (i.e., nitinol). It is recommended to use the 80 cm working length device for ipsilateral procedures. The longer working length of the 135 cm device may potentially be challenging for the user to keep straight for ipsilateral procedures. Failure to keep the device straight may impede the optimal deployment of the implant, potentially resulting in an elongated or foreshortened implant. The long-term outcomes following repeat dilatation of endothelialized stents are unknown. The safety and effectiveness of stent overlapping in the middle (P2) and distal popliteal artery (P3) has not been established. Operator deployment techniques other than those indicated by the Instructions For Use are advised against. Stent elongation or stent foreshortening are potential consequences as a result of not following the deployment Instructions for Use.

Precautions: The device is intended for use by physicians who have received appropriate training. During system flushing, observe that saline exits at the catheter tip. The delivery system is not designed for use with power injection systems. Recrossing a partially or fully deployed stent with adjunct devices must be performed with caution. Keep the device as straight as possible following removal from the packaging and while inserted in the patient. Failure to do so may impede the optimal deployment of the implant. Prior to and during stent deployment, remove slack from the delivery system catheter outside the patient by gently holding the stability sheath and keeping it straight and under tension. If excessive force is felt during stent deployment, DO NOT force the delivery system. Remove the delivery system and replace with a new unit. Store in a cool, dark, dry place. DO NOT attempt to break, damage, or disrupt the stent after placement. Cases of fracture have been reported in clinical use of the LIFESTENT® Vascular Stent. Cases of stent fracture occurred in lesions that were moderate to severely calcified, proximal or distal to an area of stent overlap and in cases where stents experienced 10% elongation at deployment. Therefore, care should be taken when deploying the stent as manipulation of the delivery system may, in rare instances, lead to stent elongation and subsequent stent fracture. The long-term clinical implications of these stent fractures have not yet been established. The safety and effectiveness of this device for use in treatment of in-stent restenosis has not been established. The GEOALIGN® Marking System is designed to be used as an additional reference tool to accompany the interventionalist’s standard operation procedure. The use of fluoroscopic imaging is recommended following positioning of the catheter to the target lesion and prior to stent deployment or balloon inflation. If the GEOALIGN® location reference is on the brown moving sheath, the location reference will move relative to the introducer hub and stability sheath as soon as stent deployment has been initiated. DO NOT try to re-align the location reference after stent deployment has been initiated. The green stability sheath should remain stationary relative to the introducer and under tension throughout deployment. Guidewire compatibility and device performance have been evaluated clinically with 0.035 inch guidewires only. Compatibility with 0.014 inch guidewires is based on non-clinical testing only.

Potential Adverse Events: Potential adverse events that may occur include, but are not limited to, the following: allergic/anaphylactoid reaction; amputation; aneurysm; angina/coronary ischemia; arterial occlusion/thrombus, arterial occlusion/restenosis of the treated vessel; arteriovenous fistula; arrhythmia; bypass surgery; death related/unrelated to procedure; embolization; fever; hemorrhage/bleeding requiring a blood transfusion; hematoma bleed; hypotension/hypertension; incorrect positioning of the stent requiring further stenting or surgery; intimal injury/dissection; ischemia/infarction of tissue/organ; liver failure; local infection, malposition (failure to deliver the stent to the intended site); open surgical repair; pain; pancreatitis; pulmonary embolism/edema; pneumothorax; pseudoaneurysm; renal failure; respiratory arrest; restenosis; septicemia/bacteremia; stent fracture; stent migration; stroke; vasospasm; venous occlusion/thrombosis

Please consult package insert for more detailed safety information and instructions for use.
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