Approach to Tibiopedal Retrograde Revascularization of Below-The-Knee Peripheral Arterial Diseases With or Without Transradial Guidance Peripheral Angiography

Abstract: Objective. We sought to compare the use of transradial peripheral angiography to guide retrograde revascularization of below-the-knee (BTK) lesions using tibiopedal access (TPA). Background. Tibiopedal retrograde revascularization of BTK lesions is an emerging technique in peripheral interventions. Methods. We performed an observational cohort study of 194 consecutive adult patients with critical limb ischemia (CLI) who underwent endovascular intervention for BTK diseases using peripheral angiography and primary TPA access with vs without transradial (TR) guidance at 2 centers (New York, USA and Budapest, Hungary). The primary endpoints were procedure success, 30-day major adverse event rate, 30-day access-site complication rate, and 30-day access-site patency rate by ultrasound. Secondary endpoints were periprocedural complications, fluoroscopy time, procedure length, and crossover rate to femoral access. Results. There were 78 patients in the TR-guidance group and 116 patients in the non-TR guidance group. Overall procedure success rates with TR guidance vs without TR guidance were 97% and 98%, respectively. Fluoroscopy times (732.8 ± 615.7 seconds vs 769.8 ± 565.8 seconds; P=NS) and procedure times (46.5 ± 24.4 minutes vs 55.4 ± 12.6 minutes; P=NS) were similar in the TR-guidance group vs the non-TR guidance group, but contrast volumes were higher in the TR-guidance group (100.0 ± 60.1 mL vs 43.8 ± 10.2 mL in the non-TR guidance group; P<.05). There was no difference in 30-day major adverse events, other than higher amputation rate in the TR-guidance group (15.3%), which was attributed to severe baseline complex CLI status in this patient group. There was 1 case of arteriovenous fistula, 1 case of pseudoaneurysm, and 1 case of tibiopedal artery occlusion at 30 days in the group without TR guidance. There were 3 cases (3.8%) of radial artery occlusion in the TR-guidance group. Conclusions. The treatment of CLI with BTK lesions is feasible and safe, with a high procedural success rate and low access-site complication rate using the TPA approach regardless of whether or not TR guidance is utilized.

Reprinted with permission from J INVASIVE CARDIOL 2020;32(1):6-11.

Key words: peripheral arterial disease, tibiopedal access, transradial

Critical limb ischemia (CLI) is a serious manifestation of peripheral arterial disease (PAD) that includes chronic ischemic rest pain, ulcers, or gangrene.^1,2 It is usually involved with severe blockage of below-the-knee (BTK) lower-extremity arteries resulting in markedly diminished blood flow to the foot. The severity of CLI depends on the extent of the anatomy of the peripheral arterial obstruction. This group of patients usually has a high risk of limb loss and increased cardiovascular events. Approximately 30%-50% of patients will have amputation in 1 year if blood flow is not restored.³ The risk of cardiac death is also noticeably increased; the rate of mortality is reported to be 48.3% at 1 year after major lower-extremity amputation.⁴ Endovascular CLI interventions are used with greater frequency nowadays.⁵ From 2003 to 2011, there was a significant increase in endovascular interventions in CLI patients  from 5.1% to 11.0%, which was accompanied by lower rates of in-hospital mortality and major amputation, as well as shorter length of stay.⁶

The typical access sites for patients who undergo endovascular interventions often rely on the common femoral artery because of its size and superficial access. However, femoral access complications can sometimes be devastating.⁷ The desire to lower the risk of femoral access complications has resulted in the use of tibiopedal access (TPA) for peripheral interventions.^8-11 TPA can also overcome some equipment problems, as the distance of TPA to BTK lesions is very feasible by using the same lengths for catheter, balloon, atherectomy device, and stent shaft compared with the femoral approach. Furthermore, this approach has important quality-of-life implications, leading to early ambulation, early discharge, and increased patient and staff satisfaction.^8,11

Utilization of transradial (TR) approach to peripheral lesions has been increasing in recent years. Interventionists may feel more comfortable performing TR-guidance peripheral angiography to help define the exact peripheral anatomy, followed by TPA retrograde revascularization of the BTK lesions.¹² However, there is additional evidence to support primary TPA approach to perform retrograde intervention without TR guidance.^8-11 Thus, in this report, we compare the feasibility, technical success, and complication rates of these two different strategies by comparing TPA retrograde intervention in BTK arteries with versus without TR guidance.

Methods

We performed an observational cohort study of 194 consecutive adult patients with CLI who underwent endovascular retrograde intervention for BTK diseases either with TR guidance (78 patients from Budapest, Hungary) or without TR guidance (116 patients from New York, New York) in the primary TPA access. The clinical and angiographic data were evaluated for patients at the 2 centers between January 2014 and December 2018. The institutional review boards of the participating sites approved the study with waiver of informed consent as all data were collected and recorded as part of routine clinical care.

The TPA approach. The protocol for TPA retrograde approach to PAD can be found in previous studies.^8-9,11 We selected patients with good distal run-off and non-infected distal puncture zone. In brief, TPA was chosen as an initial approach and performed by experienced operators. Under ultrasound guidance, the flow of anterior tibial (AT) artery, dorsalis pedis (DP) artery, posterior tibial (PT) artery, or peroneal artery was demonstrated by Doppler in the short-axis and long-axis views. The peroneal artery was accessed by fluoroscopy guidance if it was not seen by Doppler study. Either DP artery, PT artery, or peroneal artery was accessed using a 21/19 tapered-gauge echogenic-tip needle with an anterior-wall puncture technique followed by insertion of 4 Fr Pinnacle Precision sheath (Terumo). Systemic heparin was given to maintain activated clotting time >300 seconds. An intra-arterial antispasmodic cocktail consisting of 200 µg of nitroglycerin and 1 mg of verapamil was injected.

TR guidance. Operator discretion dictated whether or not to use TR guidance. In patients who underwent the TR-guidance approach, peripheral angiography was done with a 125 cm pigtail catheter placed above the abdominal aorta bifurcation via the radial artery access to guide the intervention. The choice of left or right radial artery was at operator’s discretion. The TPA was performed as mentioned above. In the group of patients who underwent TPA without TR guidance, the peripheral angiography was done in a retrograde fashion by a vertebral catheter after crossing the peripheral lesions. Atherectomy, balloon angioplasty, and/or stenting were performed retrogradely from the TPA via the same or an upsized Slender Glide sheath (Terumo) at operator’s discretion.

Ultrasound examination. Ultrasound examination of the relevant limb was done with the patient lying supine using a 7.5 MHz linear transducer. Ultrasound scan was started with grey-scale mode. Color Doppler and spectral Doppler were done on each of the major arteries. The artery was considered to have a hemodynamically significant stenosis with luminal diameter reduction by at least 50% and/or sudden marked increase in peak systolic velocity (>100% of the expected) at the area of narrowing. The artery was considered to be totally occluded if there was no demonstrable blood flow with Doppler mode and monophasic waveform in the distal arteries.

Hemostasis and clinical assessment. Hemostasis was achieved with both approaches using patent hemostasis technique utilizing compression devices (TR Band [Terumo] or Vasostat [Forge Medical]).⁸ 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; then, an additional 1 mL of air was insufflated to confirm occlusion at the puncture site. Alternatively, a Vasostat device was used; it was pushed down several clicks until no extravasation of blood occurred at the access site. Both TR Band and Vasostat distal flow were assessed by Doppler study distal to the occlusion site to confirm Doppler signal. The patient was discharged home after 2 hours of monitoring. A clinical assessment was performed prior to the discharge and at follow-up visit 1 week post intervention. At 30 days post intervention, a lower-extremity duplex ultrasound was performed to assess patency of the arteries and the access sites. Demographics and clinical variables of these patients were obtained from electronic medical records.

Endpoints. Primary study endpoints were procedure success rate, 30-day major adverse event rate, access-site complication rate, and 30-day access-site patency rate by ultrasound. Secondary endpoints were periprocedural complications, fluoroscopy time, procedure length, and crossover rate to femoral access. Procedural success was defined as successful revascularization of the BTK lesions with <30% angiographic residual diameter stenosis. Periprocedural complications included flow-limiting dissections, arterial perforations, access-site bleeding/hematomas, and distal embolization. Major adverse events included all-cause death, amputation of the target limb, or target-vessel failure requiring unplanned endovascular or surgical target-vessel revascularization (TVR).

Statistical analysis. Baseline characteristics are described per the initial strategy. Continuous variables are expressed as mean ± standard deviation and compared using Student’s t-test. Categorical data are expressed as percentages and compared using Fisher’s exact tests or Pearson’s Chi-square test, as appropriate. All statistical tests were 2-tailed and P<.05 was considered statistically significant.

Results

The baseline characteristics are shown in Table 1. A total of 194 patients were enrolled, with 78 patients in the TR-guidance group and 116 patients in the non-TR guidance group. TPA was successfully performed in all patients except 1 in the TR-guidance group who crossed over to femoral access. The patients in the TR-guidance group were older and more often male, and had less history of smoking or coronary artery disease. All patients in both groups had Rutherford class 4 symptoms or worse; however, the TR-guidance group had more patients in Rutherford class 5 and 6. Right radial artery (60%), distal radial artery (14%), right ulnar artery (1%), or left radial artery (9%) was accessed in all patients for diagnostic peripheral angiography in the TR-guidance group. The majority of patients underwent AT artery or DP artery access (69%), followed by PT artery (21%) or peroneal artery (9%). There were more patients who had all 3 vessels intervened during the same procedure in the TR-guidance group than in the non-TR guidance group (14% vs 3%, respectively; P<.05).

Outcomes. Procedural and interventional characteristics are shown in Table 2. Overall procedural success rates for the TR-guidance group and non-TR guidance group were 97% and 98%, respectively. Fluoroscopy time and procedure time were similar in the TR-guidance group vs the non-TR guidance group (732.8 ± 615.7 seconds vs 769.8 ± 565.8 seconds, respectively [P=NS] and 46.5 ± 24.4 minutes vs 55.4 ± 12.6 minutes, respectively [P=NS]). The contrast volume used in the TR-guidance group was higher compared with the non-TR guidance group (100.0 ± 60.1 mL vs 43.8 ± 10.2 mL, respectively; P<.05), most likely from the TR-guidance peripheral angiography. There were 2 cases of slow distal flow and 2 cases of flow-limiting dissection in the TR-guidance group, which were successfully treated with stenting. There were no other periprocedural complications like access-site hematomas, distal embolization, arterial perforation, or need for emergency surgery in either group. The primary endpoint of 30-day major adverse events was not significantly different between the two groups, except for a higher major amputation rate in the TR-guidance group (15.3%) due to severe baseline complex CLI status in this patient group. Major amputation was defined as an amputation due to a vascular event above the forefoot. Ultrasound follow-up demonstrated 1 case of arteriovenous fistula, 1 case of pseudoaneurysm, and 1 case of TP artery occlusion in the non-TR guidance group. There were 3 cases (3.8%) of radial artery occlusion in the TR-guidance group.

Discussion

The results of this multicenter study comparing TPA retrograde revascularization with versus without TR guidance demonstrated several important findings. First, CLI patients with BTK lesions underwent safe and feasible retrograde interventions performed by experienced operators. Second, the procedure success rates were very high (>95%) and similar in both groups. Third, although there was greater amount of contrast used in the TR-guidance group, the observed major adverse event rates were similar. Fourth, access-site complications were low in both groups despite greater use of radial artery access in the TR-guidance group.

Feasibility and safety of TPA. With the increased prevalence of complex PAD lesions, TPA has been increasingly used in recent years to facilitate retrograde complex peripheral lesion revascularization after failed antegrade approach. Previous reports have demonstrated that TPA for retrograde PAD revascularization is feasible and safe.^8-15 The earliest experience of TPA from the published literature is from Botti et al,¹⁶ who described 6 patients with CLI and retrograde tibial puncture utilized after failed antegrade access. Furthermore, Mustapha et al¹³ reported on the feasibility of ultrasound-guided retrograde tibial access in 29 patients who presented with CLI and significant tibial artery disease. Ruzsa et al¹⁴ published their experience with 51 CLI patients using TPA after failed antegrade approach; they reported failed revascularization in only 2%, with limb salvage rates of 93% at 2 months and 82.3% at 12 months. In another multicenter study, Walker et al¹⁵ reported a high crossing success rate of 85% for infrainguinal CTO via TPA without major complications. Our early experience⁸ showed that primary TPA in order to minimize femoral access-site complications as a routine approach to PAD interventions was feasible, with an access-site complication rate of 0%. Patel et al⁹ reported that both TR and/or TPA were achievable for superficial femoral artery/popliteal CTOs, with a procedural success rate of 96%. Shah et al¹¹ compared TPA with transfemoral access in a cohort of non-randomized patients with PAD interventions. Similarly, they found that there were fewer access-site complications in patients who underwent TPA. Moreover, the TPA group demonstrated less contrast use, as well as shorter fluoroscopy and procedure times. Of note, these studies used TPA retrograde revascularization without TR guidance.

TR guidance vs non-TR guidance. There are few data regarding the revascularization of BTK lesions by retrograde TPA.^8-12 TR-guidance peripheral angiography was considered to be the conventional way to define the complete anatomy before intervention. Currently, it is accepted as the gold standard to assess the anatomy of tibial vessels. TR-guidance peripheral angiography can provide full anatomical information for both inflow and outflow diseases (Figure 1). With this approach, the proximal anatomy, extent of lesion morphology, and lesion characteristics (such as CTO) can be considerably defined. However, the procedure is not without risk. The increased contrast volume during the TR-guidance approach can be attributed to performing peripheral angiography. This extra risk can be limited by using CO₂ angiography, but this technique was not utilized in the present study. In patients with renal insufficiency, the extra amount of contrast might cause concern. In addition, the TR-guidance procedure might have extra risk from radial access complications, inadvertent vascular risk, or stroke. Despite these disadvantages, the additional radial artery access can be obtained to treat the proximal lesions in a single session, and to properly visualize the distal run-off (plantar arch, collaterals). Recently, there has been an increased interest in using ultrasound imaging to assess tibial vessel anatomy. According to a study by Mustapha et al,¹⁸ ultrasound can accurately detect tibial vessel patency or occlusion in around 80% of the segment. Rather than undergoing full peripheral angiography and assessment of the entire anatomy, patients undergoing intervention without TR guidance rely fully on the ultrasound assessment at the time of the procedure. In contrast to the TR-guidance group, retrograde peripheral angiography is undertaken from the TPA (Figure 2A). After crossing the lesion, another angiogram is performed to access the length and anatomy (Figure 2B). While going retrograde from TPA, the operator may not fully be aware of the proximal anatomy, sometimes making it difficult to re-enter the true lumen if there is a CTO lesion. Extensive retrograde dissection may result if the length of the CTO lesion is not recognized. However, in this study, there was no evidence of flow-limiting dissection in the group without TR guidance. Furthermore, there were no excessive access-site complications in either group and the procedure success rates were similar in both groups. Even with greater contrast usage in the TR-guidance group, the 30-day major adverse event rates were similar with the use of either strategy, except for the amputation rates in the TR-guidance group; however, this could be related to the very severe CLI in this group, in which 35% of patients had Rutherford 6 classification. Despite successful revascularization, major amputation still could not be avoided in 15.3% of these patients. However, this is still a better outcome than with no revascularization. The results of this study demonstrated that both approaches are simple, feasible, and comparable methods to revascularize BTK lesions from retrograde TPA. Furthermore, retrograde access can be utilized for pedal arch reconstruction (which is an important predictor of plantar wound healing) by puncturing the contralateral tibial vessel and doing a pedal-to-pedal crossover in the tibial vessels (Figure 3). In the real world, interventionists are better-trained radialists and are more comfortable defining the peripheral anatomy and assessing peripheral vessels from the TR approach. Since there is no difference in the procedure success rates with or without TR guidance, we should anticipate that TPA will be easily adopted for peripheral interventions by operators who are proficient in the TR techniques. We also speculate that primary TPA with bail-out TR guidance will be increasingly performed once operators are familiar with this technique.

Study limitations. We note several limitations in this study. First, this is not a randomized study and is therefore subject to selection bias, eg, by country of origin, operators, and more severe CLI patients in the TR-guidance group. Second, TPA was done at a center with large-volume operators who are familiar with both TR and TPA techniques; thus, the results may not be extrapolated to centers with operators who are not familiar with similar equipment, puncture techniques, and patent hemostasis techniques.

Conclusion

The treatment of CLI with BTK lesions is feasible and safe using the TPA approach and can achieve a high procedure success rate with low access-site complication rate regardless of whether TR-guidance peripheral angiography is used.

From the ¹Mount Sinai Beth Israel, New York, New York; ²Mount Sinai West, New York, New York; ³Chinatown Cardiology, PC, New York, New York; ⁴Houston Methodist DeBakey Heart and Vascular Center, Houston, Texas; ⁵Semmelweis University, Heart and Vascular Center, Budapest, Hungary; and ⁶Bács-Kiskun County Hospital, Teaching Hospital of the Szent-Györgyi Albert Medical University, Kecskemét, Hungary.

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.

The authors report that patient consent was provided for publication of the images used herein.

Manuscript submitted March 3, 2019, provisional acceptance given July 5, 2019, final version accepted October 11, 2019.

Address for correspondence: Tak W. Kwan, MD, Clinical Professor of Medicine, Icahn School of Medicine at Mount Sinai, 139 Centre St., Rm 307, New York, NY 10013. Email: Kwancardio@aol.com