Feasibility and Safety of Routine Transpedal Arterial Access for Treatment of Peripheral Artery Disease

Abstract: Objective. To demonstrate the feasibility and safety of transpedal arterial access for lower-extremity angiography and intervention. Background. Traditionally, the femoral artery is chosen for the initial access site in symptomatic peripheral artery disease (PAD), but this approach carries a substantial portion of the entire procedural complication risk. Methods. 80 patients were prospectively evaluated for the treatment of PAD between May and July 2014. All patients underwent peripheral angiography, and intervention if necessary. A pedal artery was the initial access site for all patients. Under ultrasound guidance, one of the pedal arteries was visualized and accessed, and a 4 Fr Glidesheath was inserted. Retrograde orbital atherectomy and balloon angioplasty were performed with a 4 Fr sheath or upsizing to a 6 Fr Glidesheath Slender (Terumo) for stenting as needed. Clinical and ultrasound assessment of the pedal arteries were performed before the procedure and at 1-month follow-up. Results. Diagnostic transpedal peripheral angiography was performed in all 80 patients. 43 out of 51 patients (84%) who required intervention were successful using a pedal artery as the sole access site. No immediate or delayed access-site complications were detected. Clinical follow-up was achieved in 77 patients (96%) and access artery patency was demonstrated by ultrasound at 1 month in 100% of patients. Conclusion. The routine use of a transpedal approach for the treatment of PAD may be feasible and safe. Pedal artery access may also avoid many of the complications associated with the traditional femoral approach, but further study is needed. 

J INVASIVE CARDIOL 2015;27(7):327-330

Key words: intermittent claudication, transpedal access, peripheral vascular disease

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Peripheral artery disease (PAD) is a common and debilitating disease affecting more than 8 million people in the United States.¹ Clinical manifestations and repercussions include claudication, ulceration, infection, and even amputation. While endovascular intervention for obstructive PAD has become routine, this treatment option is not without significant risks. A substantial part of the procedural complication risk is the traditional choice of the femoral artery as the initial access site.² Complications from transfemoral access include retroperitoneal bleed, hematoma, pseudoaneurysm, and arteriovenous fistula. Similar to the rise of the transradial approach for coronary interventions, alternative arterial access sites have been explored to limit these complications. In the RIVAL study, when comparing the rates of major bleeding and major vascular complications, radial artery access was superior to femoral artery access, with a hazard ratio of 0.43.³ Despite the limitations of the transfemoral approach, studies using alternative access sites for the treatment of PAD are limited. The current study hypothesizes that the transpedal approach may be a feasible, safe alternative for the routine evaluation and treatment of PAD.

Methods

A retrospective review of 80 consecutive patients who were referred for the evaluation and treatment of symptomatic PAD and underwent peripheral angiography via pedal artery access at our institution from May 2014 to July 2014 was conducted. Patient data were prospectively entered into a dedicated database. Pedal artery access was chosen as an initial approach and performed by experienced transradial operators (>300 cases/year). Under ultrasound guidance by an experienced technician (Figure 1), the flow of dorsalis pedis (DP) artery, posterior tibial (PT) artery, or peroneal artery was demonstrated by Doppler in the short-axis and long-axis views. Either DP artery, PT artery, or peroneal artery was accessed with a 21 gauge Jelco angiocath (Smiths Medical) using a double-wall puncture technique followed by insertion of a 4 Fr Glidesheath (Terumo Corporation), or with a 21 x 19 tapered-gauge echogenic-tip needle with an anterior wall puncture technique followed by 4 Fr Pinnacle Precision (Terumo Corporation). Systemic heparin was given to maintain activated clotting time >250 seconds. An antispasmodic cocktail of 100 µg nitroglycerin and 2.5 mg verapamil was injected intraarterially. If a significant lesion was identified, orbital atherectomy with a 1.25 mm burr (Cardiovascular Systems, Inc) and balloon angioplasty was performed via the 4 Fr sheath from the retrograde approach. If stenting was deemed necessary, the sheath was upsized to a 6 Fr Glidesheath Slender, which employs a smaller outer diameter that is equivalent to a standard 5 Fr sheath. 

After the procedure, a large TR Band (Terumo Corporation) was placed at the access site for 1 hour (Figure 2) using the patent hemostasis technique⁴ with certain modifications. In brief, the TR Band was inflated at the site of pedal puncture and the sheath removed. The TR Band was deflated slowly until the appearance of blood flow; an extra 1 cc of air was then added, which confirmed occlusion at the puncture site. The patient was discharged home after 2 hours of monitoring. A clinical assessment was performed prior to the intervention and 1 month afterward. A lower-extremity duplex ultrasound was performed before and 1 month after the intervention to assess patency of the arteries and the access sites by the same ultrasound technician. The protocol was approved by the local institutional review board and informed consent was obtained in all patients.

Results

All 80 patients had symptoms of PAD – 70 patients (87%) had Rutherford class 2-4 symptoms and 10 patients (13%) had minor tissue loss or Rutherford class 5 symptoms. Baseline demographics are shown in Table 1. Five patients had an absent Doppler signal of the pedal arteries so transpedal puncture was not attempted. Of the 75 patients who underwent transpedal artery puncture, 74 (99%) had successful pedal artery access. One patient demonstrated severe arterial spasm and required conversion to femoral access. Additionally, in 2 patients, the pedal artery was successfully accessed, but femoral artery access was also required to complete the procedure. A total of 8 patients (10%) required femoral artery access for these various reasons.

Fifty-one patients (64%) underwent successful peripheral artery intervention, including 22 superficial femoral arteries (SFA), 29 anterior tibial (AT) arteries, 16 posterior tibial (PT) arteries, and 14 peroneal arteries. Infrapopliteal lesions were treated to improve outflow or improve access to SFA lesions. These lesions were treated with orbital atherectomy with 1.25 mm burr, balloon angioplasty (Figures 3A and 3B), or stent placement (Figure 4). The patients who did not undergo intervention were either medically managed or worked up for other causes of their symptoms. Six patients underwent intervention of 2 tibial vessels, but still required only 1 transpedal access site. Forty-three of the 51 patients (84%) who received interventions were performed via sole transpedal access. In this patient cohort, the average fluoroscopy time was 367.9 ± 406.1 seconds. The average amount of contrast used was 37.6 ± 9.3 cc. The average radiation exposure was 24.1 ± 31.1 mGy. Clinical follow-up was achieved in 77 patients (96%). Seventy-two of the 75 patients (96%) in which transpedal puncture was attempted returned for follow-up. All patients reported improvement of symptoms. Pedal artery patency was demonstrated in 100% of these patients with an ultrasound, which was performed by the same experienced technician at the 1-month follow-up exam (Table 2). There were no immediate or late complications, including bleeding, hematoma, pseudoaneurysm, arteriovenous fistula, nerve damage, access-site artery occlusion, or other adverse events at any time period during follow-up. 

Discussion

The results of the current study show that initial transpedal access for peripheral artery angiography and interventions is feasible, safe, and may avoid many of the complications seen with the traditional transfemoral approach. This is the first described case series demonstrating a routine transpedal approach for endovascular treatment of PAD. In this retrospective, consecutive series of patients, we demonstrate several important findings: (1) the conversion rate to femoral access is low; (2) successful intervention using pedal artery as the sole access site is feasible; (3) procedural pedal artery access-site complications can be minimized; and (4) 1-month transpedal access-site patency is high.

In the currently published literature, pedal artery access has been described primarily for the treatment of critical limb ischemia (CLI) involving mostly infrapopliteal vessels either as an adjunct or bail-out strategy after failed antegrade approach.^5-9 Mustapha and colleagues recently described their experience in a retrospective case series of 23 patients where a retrograde approach via pedal artery access was used for severe PAD and CLI only. An antegrade femoral approach was considered either high risk for access-site complications or technically challenging.⁵ The authors reported no complications associated with pedal artery access. Similarly, Walker and colleagues described their experience with a primary retrograde approach in 228 CLI patients, often after failed antegrade attempt.⁶ In this study, 1 arterial site occlusion and 2 peroneal artery pseudoaneurysms requiring covered stent placement were seen. Previously, Montero-Baker and colleagues described 51 cases (including 6 claudicants) with pedal access after failed antegrade approach, and reported 1 access-site occlusion and 2 perforations and hematomas.⁷ Furthermore, Rogers et al reported a case series of 13 patients, including 3 patients with intermittent claudication, treated using transpedal access after a failed antegrade approach.⁸ Access was successfully obtained in all patients except for 1 who required a surgical cutdown; subsequently, the procedural success rate was only 85%. The present case series is unique in that it is the first study to describe pedal artery access as a primary approach in all patients with PAD requiring an invasive evaluation and management while using a systematic approach including routine ultrasound follow-up. Similar to previous reports, the current study found a high procedural success rate for transpedal access. More importantly, the procedure was found to be safe, as there were no access-site complications or arterial occlusions up to 1 month post procedure. Occlusion rates for pedal artery access have not been reported, but appear to be sufficiently low. Furthermore, the excellent transpedal access patency rate seen in this study can be attributed to the use of primarily a 4 Fr Glidesheath, systemic heparin, antispasmodic medications, patent hemostasis technique, and relatively short occlusion time. Combined with the experience of seasoned transradial operators, attention to these factors may reproduce high pedal artery patency rates in future studies. 

Advantages of the transpedal approach. In addition to minimizing femoral artery access-site complications, the transpedal access approach has other advantages. Given the straight course of the arteries above the ankle, transpedal access for peripheral intervention may present a more straightforward approach without encountering some of the difficulties of crossing over the aortic bifurcation when treating contralateral disease transfemorally. It should be noted that an ipsilateral antegrade approach is another alternative treatment option. In certain cases of difficult aortic bifurcations, the transpedal approach may lead to shorter procedure times and therefore less radiation exposure for both operators and patients. Furthermore, less scatter radiation will be emitted secondary to the lower mass content of the lower extremities compared to the abdominal region. In addition to the safety benefits, a shortened time to postprocedural ambulation will improve patient satisfaction and decrease recovery time in the treatment facility, allowing more efficient work flow. Although the true economic impact must be further investigated after broader adoption of the technique in high-volume centers, the decreased recovery times may translate to lower staffing costs and use of facility resources. Finally, the development of alternative access sites will allow operators to offer endovascular treatment options to patients who previously may have been excluded from these procedures due to difficult femoral access, ie, hostile groins.

Disadvantages of the transpedal approach. In patients with chronic total occlusion of the SFA, sole transpedal access may make it difficult to define the extent of the lesion and therefore make the intervention more challenging. Also, encountering totally occluded pedal arteries after obtaining access in the proximal portion of the vessel (eg, an occluded, collateralized distal AT artery after DP access) can be challenging. Before angiography, clinical signs of the problem were the inability to advance the wire or sheath, as well as poor flow on aspiration of the sheath. In the present study, alternative access was then obtained in another pedal artery, but only in CLI patients where benefits outweighed risks. When this approach failed or a patent pedal artery with good flow on Doppler was absent, a traditional common femoral artery puncture was performed. Another limitation to the transpedal approach is encountered with interventions on multiple tibial vessels. As seen in this study, the intervention can still be performed via the retrograde approach; however, the presence of severely angulated below-the-knee vessel bifurcations will make guidewire manipulation extremely challenging. In these cases, the lesions should be treated via the femoral approach, where the individual arteries can be approached with a more favorable angle.

Learning curve. Similar to transradial coronary intervention, the adoption of transpedal peripheral intervention will be associated with a learning curve to become proficient. However, the operators in this study believe that the learning curve may be shorter than anticipated, especially for operators already experienced with the transradial approach. In addition, operators will need to become comfortable with ultrasonic guidance of transpedal access, which has a major advantage in locating the ideal pedal artery. The pedal arteries have more atherosclerotic disease and are very difficult to access by palpation alone. 

Study limitations. This is a single-center, retrospective case series of transpedal artery access, but the results should prompt larger, multicenter, prospective, randomized controlled trials to provide validation of this approach. Also, since the transpedal technique was modeled by a center with large-volume transradial operators, the results may not be extrapolated to centers with operators who are not familiar with specific equipment, puncture techniques, and patent hemostasis techniques.

Conclusion

The routine use of transpedal access alone for the evaluation and treatment of PAD is feasible and safe. Pedal artery access may also avoid many of the complications associated with the traditional femoral approach. While these results are promising, further investigation is critical to establish the risks, benefits, safety, and efficacy of pedal artery access for the treatment of PAD. 

References

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2. Kiemeneij F, Laarman GJ, Odekerken D, et al. A randomized comparison of percutaneous transluminal coronary angioplasty by the radial, brachial and femoral approaches: the ACCESS study. J Am Coll Cardiol. 1997;29:1269-1275.
3. Jolly SS, Yusuf S, Cairns J, et al; for the RIVAL trial group. Radial versus femoral access for coronary angiography and intervention in patients with acute coronary syndromes (RIVAL): a randomised, parallel group, multicentre trial. Lancet. 2011;377:1409-1420.
4. Pancholy S, Coppola J, Patel T, Roke-Thomas M. Prevention of radial artery occlusion — patent hemostasis evaluation trial (PROPHET study): a randomized comparison of traditional versus patency documented hemostasis after transradial catheterization. Catheter Cardiovasc Interv. 2008;72:335-340.
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7. 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;83:987-994.
8. Rogers RK, Dattilo PB, Garcia JA, Tsai T, Casserly IP. Retrograde approach to recanalization of complex tibial disease. Catheter Cardiovasc Interv. 2011;77:915-925.
9. Walker C. Pedal access in critical limb ischemia. J Cardiovasc Surg (Torino). 2014;55:225-227.

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From ¹Chinatown Cardiology, P.C., New York, New York; ²Mount Sinai Beth Israel, New York, New York; ³West Virginia University, Charleston, West Virginia; ⁴Brody School of Medicine at East Carolina University, Greenville, North Carolina; ⁵The Commonwealth Medical College, Scranton, Pennsylvania; and ⁶Apex Heart Institute, Ahmedabad, India.

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 September 8, 2014, provisional acceptance given October 22, 2014, final version accepted November 26, 2014.

Address for correspondence: Tak W. Kwan, MD, 139 Centre Street, Rm 307, New York, NY 10013. Email: kwancardio@aol.com