Superficial Femoral Artery Intervention by Single Transpedal Arterial Access
Abstract: Background. Atherosclerotic disease of the superficial femoral artery (SFA) is frequently seen and can be treated with percutaneous interventions, traditionally via femoral artery access. There are limited reports of transpedal artery access for peripheral artery interventions, but none to date describing routine primary transpedal artery approach for SFA stenting. Methods. In this preliminary study, we report 4 patients who underwent successful endovascular SFA stenting using a single transpedal artery access via a new ultra-low profile 6 Fr sheath (Glidesheath Slender; Terumo Corporation). Results. All patients underwent successful SFA stenting without complication. Procedure time varied from 51 to 72 minutes. The mean contrast amount used was 56 mL; mean fluoroscopy time was 21 minutes; mean radiation dose was 91 mGy. At 1-month follow-up, duplex ultrasonography showed that all pedal arteries had remained patent. Conclusions. Transpedal artery approach as a primary approach to SFA stenting appears feasible and safe. Comparative trials with standard percutaneous femoral approach are warranted.
J INVASIVE CARDIOL 2015;27(11):E236-E241
Key words: superficial femoral artery, transpedal access, peripheral artery disease, stent
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Peripheral artery disease (PAD) is a common disease, affecting more than 8 million people in the United States alone.1 Superficial femoral artery (SFA) obstruction is frequently seen in patients with PAD, and can be treated with percutaneous interventions including balloon angioplasty, atherectomy, and/or stenting.2 Traditionally, SFA interventions are performed via anterograde femoral access or via contralateral common femoral artery puncture. However, femoral access is associated with complications such as arteriovenous fistulas, pseudoaneurysms, hematomas, and retroperitoneal bleeding; the latter complication potentially leads to fatal events or blood transfusions. As a result, different access sites, including radial, brachial, popliteal, and pedal, have been proposed to lower the risks associated with femoral artery procedures.3
For most peripheral interventions, we have been developing experience with the transpedal approach as the preferred access site, sometimes with dual access using a combined radial approach.3 However, one concern with the transpedal approach is the relatively smaller size of pedal arteries and potential trauma from the use of larger equipment. Recently, a unique, ultra-low profile sheath (Glidesheath Slender; Terumo Corporation) with an outer diameter of 2.4 mm (equivalent to a 5 Fr sheath, but with a large inner lumen of 2.2 mm) that can accommodate 6 Fr equipment has gained popularity for transradial procedures. In this initial case series, we describe our experience with transpedal approach as the single access site in the treatment of SFA disease requiring stent placement.
Methods
In this preliminary experience, we treated 4 consecutive patients requiring stent placement in the SFA for symptomatic PAD or critical limb ischemia (CLI) who had failed medical management with exercise programs. Lesions were characterized with the Trans-Atlantic Inter-Society Consensus II (TASC II) classification system.4 The dorsalis pedis, anterior tibial, or posterior tibial arteries were identified by ultrasound examination and arterial flow was confirmed by Doppler technique. Once an access site was chosen in a patent pedal artery, a 21 gauge needle was used for arterial puncture under ultrasound guidance (Figure 1). A 4 Fr Glidesheath (Terumo Corporation) was inserted over the guidewire. After confirming arterial flow, 5000 units of heparin were given intravenously and an antispasmodic cocktail of nitroglycerin 100 µg and verapamil 2.5 mg was administered intraarterially. Additional heparin was given if required to maintain the activated 
clotting time (ACT) >250 seconds. A 0.014˝ Regalia XS 1.0 guidewire (Asahi Intecc) loaded inside a 125 cm, 4 Fr Tempo Aqua hydrophilic coated vertebral catheter (Cordis Corporation) was used to perform a diagnostic angiogram in the affected extremity (Figure 2).
Once the obstructive lesions were identified and the plan was made to treat the affected limb, the 4 Fr sheath was upsized to a 6 Fr Glidesheath Slender (Figure 3). A 1.25 mm or 1.5 mm Stealth 360 Solid Crown (CSI) was used for orbital atherectomy at the operator’s discretion. The target lesion was predilated with a compliant balloon. Self-expanding SMART nitinol stents (Cordis Corporation) were placed across the target lesions followed by post-stent balloon dilatation (Figure 4). After successful intervention, a large TR Band (Terumo Corporation) was placed to achieve patent hemostasis at the pedal access site (Figure 5), as similarly used in radial artery access.5 Dual-antiplatelet therapy was prescribed in all patients for at least 3 months. Patients were discharged home 2 hours after intervention and completion 
of hemostasis. Follow-up visit at 1 week post intervention included routine clinical exam. At 1 month post intervention, a lower-extremity vascular duplex ultrasound was performed to assess stent and access-site patency.
Results
Patient #1. A 74-year-old man who had lifestyle-limiting intermittent claudication despite aggressive medical therapy with exercise was referred for peripheral angiography. Left dorsalis pedis artery (DPA) was accessed under ultrasound guidance. A 4 Fr sheath was placed and angiography was performed, which showed TASC B, 95% stenosis 
with severe calcification of both left proximal and distal SFA (Figure 2). Additionally, an 80% stenosis in the left proximal anterior tibial artery (ATA) was noted, with 3-vessel run-off to the foot. Due to the presence of heavy calcification, orbital atherectomy was performed followed by balloon angioplasty, but significant residual stenosis (60%) mandated stent placement. Two self-expanding stents were placed across the proximal and distal SFA lesions (7.0 x 60 mm and 7.0 x 40 mm, respectively) without complication. Postdilation was performed with 20% residual SFA stenosis. Subsequently, orbital atherectomy was performed in the left ATA lesion followed by a 3.5 x 60 mm balloon dilation, leaving a 10% residual stenosis. A total of 60 mL of contrast was used and fluoroscopy time was 13 minutes. The access site was patent on arterial duplex at 1-month follow-up exam.
Patient #2. A 76-year-old woman with progressively worsening intermittent claudication despite medical management was noted to have severe obstructive disease within the left SFA by arterial ultrasound. Outpatient angiography was performed via the left DPA and showed a long, TASC D, 80% stenosis of the left mid SFA and 80% stenosis of the left ATA with 3-vessel run-off. Orbital atherectomy followed by balloon angioplasty resulted in flow-limiting dissection requiring a 6.0 x 150 mm stent placed across the mid SFA lesion. A 5.0 x 100 mm postdilation balloon was then used to optimize the stent. Following SFA intervention, ATA intervention was performed via orbital atherectomy followed by balloon angioplasty. At routine 1-month follow-up visit, the arterial duplex demonstrated access-site patency.
Patient #3. A 79-year-old man with right SFA stent placed two years prior presented with severe right leg claudication despite attempts at a regular exercise program. Lower-extremity arterial duplex revealed occluded right SFA bare-metal stent with weak collateral flow in the popliteal and tibial arteries. Peripheral angiography via the right DPA showed a TASC D, total in-stent occlusion of the right mid SFA. Orbital atherectomy was performed, followed by balloon angioplasty after successful wiring across the lesion. However, a 60% residual stenosis remained, which required stent placement. A self-expanding 7.0 x 100 mm stent was placed across the mid SFA followed by postdilation with no residual stenosis. Access-site patency was seen on the arterial duplex at routine 1-month follow-up exam.
Patient #4. An 89-year-old man presented for outpatient treatment of bilateral lower-extremity claudication, worse in the left leg, after a significant stenosis of the left SFA was found on ultrasound. Ultrasound-guided cannulation of the left posterior tibial artery (PTA) was obtained after local anesthetic. Angiography showed a calcified, TASC B, 100% stenosis of the left mid SFA with reconstitution distally, and both PTA and ATA contained 80% stenoses. Orbital atherectomy was followed by balloon angioplasty, which resulted in dissection with no flow. Three self-expanding stents (7.0 x 150 mm, 7.0 x 60 mm, and 6.0 x 150 mm) were placed across the SFA lesion with good angiographic result and minimal residual stenosis. Subsequently, orbital atherectomy and balloon angioplasty were performed on the severe left PTA lesion with 10% residual stenosis. Routine arterial duplex at 1-month follow-up exam revealed patent access-site flow.
There were no acute access-site complications. No bleeding, hematomas, pseudoaneurysms, arteriovenous fistulas, nerve damage, retroperitoneal bleeds, or adverse vascular events were noted on clinical follow-up visits at 1 week and 1 month post procedure. The mean contrast amount used was 56 mL, mean fluoroscopy time was 20 minutes, and mean radiation dose was 91 mGy. Procedural details of each case are summarized in Table 1. The patients presented for routine follow-up visit and were found to have a patent access site on arterial duplex.
Discussion
This is the first case series describing a transpedal approach for SFA stenting using an ultra-low profile 6 Fr sheath. In this small series of patients, we demonstrated several important findings: (1) successful SFA stenting via 6 Fr Slender sheath can be achieved using a pedal artery as the single access site; (2) no patient required conversion to contralateral femoral artery access; (3) no pedal artery access-site complication was encountered; and (4) 1-month duplex ultrasound follow-up revealed 100% access-site patency.
We recently published the first description of routine primary pedal artery access for lower-extremity angiography and PAD interventions.6 In this study, we show that SFA interventions requiring stent placement can be performed successfully via single transpedal approach.
Historically, pedal artery access has been described in the treatment of CLI mostly involving infrapopliteal vessels, either as an adjunct or bail-out access after failed antegrade approach (Table 2).7-11 These series differ in primary access, intervention location, and assessment of access-site patency. Mustapha et al described attempts at primary pedal artery access, but only for the intervention of infrapopliteal lesions.9 In the largest series of 217 patients, transpedal stenting of SFA (as a secondary access site after failed antegrade approach) was performed in 57% of SFA lesions. However >95% of these patients had stents deployed via antegrade approach. There were only 5 patients in this series with standard 6 Fr sheaths inserted into the pedal artery.11 There was one acute access-site occlusion after using a 6 Fr sheath in a small artery. However, there was no mention of follow-up access-site patency. In contrast to our study, access-site patency at follow-up was not assessed in any prior series. Similar to previous reports, our technique had a high success rate. Most importantly, we use pedal arteries as the primary and only access site for the treatment of suprapopliteal vessels. We did not encounter any access-site complications or occlusions at 1-month follow-up.
Occlusion rates for pedal artery access are unknown. Sheath size correlates highly with radial artery occlusion rate, as demonstrated by Saito et al.12 Similar to the radial artery, we expect that access-site patency of the pedal arteries is in part influenced by sheath size, such that the larger the sheath, the greater the trauma to the small-caliber pedal artery, and therefore the higher potential for access-site complication. Conversely, larger sheath size is necessary for stent placement and other bulky peripheral interventional equipment. We believe the availability of a novel ultra-low profile 6 Fr sheath opens new opportunities for transpedal approach and peripheral artery stenting. This sheath provides a significant two-fold advantage for transpedal access, ie, accommodating the necessary interventional equipment while minimizing pedal artery trauma.
Besides avoiding some common femoral artery access-site complications, the transpedal approach has other advantages. The transpedal route is a more direct approach, given the artery’s straight course and lack of severe tortuosity, compared with the transradial or transfemoral technique. This may translate into less radiation exposure for operators and patients. The average radiation dose to the patients in our series was 91 mGy for multilesion interventions, compared with approximate average air Kerma of 163 mGy in femoral artery interventions of similar lesion complexity in other studies.13 In addition to patient safety and comfort with transpedal access, the shortened time to postprocedural ambulation and overall recovery time should also translate into less economic burden for both in-hospital or outpatient peripheral labs.
There are also several disadvantages associated with this access technique. Patients with SFA chronic total occlusions can be intervened by transpedal access alone. However, without knowing the proximal vessel anatomy, it can be difficult to fully define the proximal lesions via transpedal angiography. At times, dual radial or femoral and pedal artery access may be necessary for more complex interventions. Successful access puncture is dependent on preprocedural ultrasound interrogation to demonstrate pedal artery and proximal arterial patency. Based on our experience, occluded mid or distal pedal arteries have proven inability to advance the wire or sheath with subsequent poor blood flow on aspiration via sideport from the sheath. Therefore, alternative access should be obtained, typically in another pedal artery.
This is a small case series, which suggests that this novel technique for SFA stenting can be successfully achieved with standard angioplasty equipment using a relatively smaller sheath. These cases were conducted by experienced transradial operators; consequently, results may not be reproducible by operators who are not familiar with specific equipment, puncture methods, and patent hemostasis techniques.
Conclusion
Transpedal approach using an ultra-low profile 6 Fr sheath is feasible for SFA stenting. Endovascular techniques developed for radial artery access can be applied to pedal artery access sites as well, since both have similar challenges. Trials with larger cohorts and comparative trials with standard approach are necessary to confirm the feasibility and safety of this approach.
References
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From 1Mount Sinai Beth Israel, New York, New York; 2New York University Langone Medical Center, New York, New York; and 3Quebec Heart-Lung Institute, Quebec, Canada.
Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.
Manuscript submitted May 11, 2015, provisional acceptance given May 12, 2015, final version accepted May 28, 2015.
Address for correspondence: Tak W. Kwan, MD, Mount Sinai Beth Israel Heart Institute, 16th Street at First Avenue, New York, NY 10013. Email: kwancardio@aol.com
