Impact of Pedal Arch Patency on Below-the-Ankle Revascularization Outcomes

This Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective cohort study was approved by the institutional review board, and informed consent was waived.

Patient selection. Consecutive patients who underwent EVT for lower-extremity CLI at a single community hospital system were identified through retrospective review of electronic medical records. Only Rutherford class 5-6¹⁷ CLI cases involving revascularization of a named pedal artery (dorsalis pedis, medial and lateral plantar, pedal arch) were included regardless of proximal intervention. Cases involving iliac, femoropopliteal, and/or tibial revascularization without BTA intervention were excluded, even if pedal access was employed. Sixty patients (age, 69.1 ± 1.5 years; 58.3% men) were identified whose demographics and comorbidities are listed in Table 1. Wound status and vascular lesion characteristics are shown in Table 2. All patients underwent a single EVT session to treat a total of 81 pedal lesions in addition to 84 tibial lesions. There were no patients who underwent BTA angioplasty without concurrent tibial revascularization. Thirty-three of the 60 patients (55%) underwent concurrent femoropopliteal intervention.

Procedure. The goal of EVT in all cases was to establish direct, inline flow to the affected wound bed in the foot. When lack of direct flow to target wound bed remained following femoropopliteal or tibial EVT, plain balloon angioplasty was performed in the pedal arteries to improve angiosome-directed angiographic perfusion. In order to achieve this, advanced techniques such as the pedal-plantar loop technique⁹ and retrograde pedal access technique^18,19 were selectively employed as needed. All pedal artery lesions underwent balloon angioplasty. Pedal artery atherectomy was used prior to angioplasty per operator discretion using the Jetstream device (Boston Scientific) in 1 case and the Diamondback 360º device (Cardiovascular Systems, Inc) in 2 cases. Pedal artery stent placement was not performed. Completion arteriograms were classified as complete (CPA), incomplete (IPA), or absent (APA) pedal arch. CPA was defined as angiographic continuity between a plantar artery and the dorsalis pedis; IPA was defined as patency of either a plantar artery or the dorsalis pedis; and APA was defined as absence of both plantar arteries and the dorsalis pedis (Figure 1).^15,16

Postprocedural care. Patients were started on dual-antiplatelet therapy (aspirin 81 mg daily with a clopidogrel 300 mg loading dose immediately at the conclusion of the procedure followed by 75 mg of clopidogrel daily) or continued their existing antiplatelet/anticoagulation regime. Patients were seen for follow-up by the operating physician to assess wound healing. Selective reintervention was driven by patient symptoms, status of wounds, and congruent findings on non-invasive testing of recurrent occlusion or hemodynamically significant stenosis within a previously treated vessel supplying the wound bed(s).

Study endpoints and data analysis. Technical success was defined as recanalization of an obstructing lesion that resulted in patent angiosome-directed pedal outflow to the target wound bed, regardless of whether CPA was achieved. Clinical endpoints included overall survival (OS), amputation-free survival (AFS), and freedom from minor amputation (FFA-minor) at 6 and 12 months. AFS was defined as time from index procedure to either death or major amputation (through or above the ankle).²⁰FFA-minor was defined as avoidance of a toe or ray amputation in the absence of ipsilateral major amputation or death.⁷ Wound healing rate and time were assessed throughout the duration of follow-up. Wound healing was defined as complete epithelialization without major amputation.¹⁰ These endpoints were also reported for a subgroup analysis comparing patients with CPA vs IPA after the procedure. Adverse procedure-related events were reported according to the Society of Interventional Radiology reporting standards.²¹

Statistical analysis. Continuous variables were expressed as mean ± standard error. The Chi-square test and Fisher’s exact test were used to compare binomial variables, with the latter utilized when cell sizes were <5. The Mann-Whitney U-test was used to compare continuous variables. Kaplan-Meier survival curves were generated, and subgroup analyses were performed to compare pedal arch groups and clinical endpoints using the log-rank (Mantel-Cox) test. Two-tailed statistical significance was set at P<.05. All statistical analyses were performed using SPSS software, version 20 (IBM Corporation).