Auryon Laser in Peripheral Arterial Interventions: A Single-Center Experience (Auryon-SCE)

Abstract

Background. The Auryon 355-nm laser atherectomy system (AngioDynamics, Inc) showed a low rate of target-lesion revascularization (TLR) at 6-month follow-up in the investigational device exemption study. At present, real-world data are not available. In this study, we analyze major adverse events and 6-month outcomes with the Auryon laser system in treating infrainguinal arterial disease in all comers at a single center. Methods. Consecutive patients treated with the Auryon laser between September 2017 and March 2021 were retrospectively reviewed from a single operator at a single center. Demographic, procedural, angiographic, and outcome data were extracted from patients’ medical records. Descriptive and survival analyses were performed. The study’s primary endpoint was the assessment of freedom from TLR at 6-month follow-up. Secondary endpoints included acute procedural results, distal embolization, bailout stenting (dissection type D or higher by National Heart, Lung, and Blood Institute [NHLBI] classification, and/or residual narrowing >30%), unplanned major amputation, death, or vascular complications. Results. A total of 56 patients (65 procedures, 70 lesions) were enrolled. The mean age was 70.9 ± 10 years, 66.1% were males, 48.2% were diabetics, and 25% had limb ischemia. Of the 70 lesions, 31.4% had severe calcification, 38.6% were chronic total occlusions, and 48.6% were de novo disease (in-stent restenosis in 28.6%). The majority of treated vessels were femoropopliteal (88.6%) and 29.2% had 2 or more prior interventions. Mean stenosis was 91.3 ± 9.7% at baseline, 56.0 ± 17.3% post laser, and 11.4 ± 11.2% post final treatment. Lesion length was 117.1 ± 101.2 mm and treated length was 174.0 ± 116.0 mm. Bailout stenting occurred in 11/70 lesions (15.7%). There were no NHLBI type D dissections post laser and 1 type D dissection post laser + percutaneous transluminal angioplasty. A total of 47.1% received Lutonix drug-coated balloons (BD/Bard), 27.1% received In.Pact drug-coated balloons (Boston Scientific), and 1.4% received both. The probability of freedom from TLR per procedure was 95.6% at 6 months. Conclusion. In a real-world cohort of patients with complex disease, the Auryon laser had excellent freedom from TLR at 6 months, although these findings need to be replicated in a randomized trial.

Keywords: atherectomy, Auryon, de novo, laser, real-world, registry, restenosis, retrospective, target-lesion revascularization

The Auryon laser atherectomy system (AngioDynamics, Inc) has a long wavelength (355 nm) and a short pulse duration (10-25 ns), yielding a higher energy power to ablate calcified disease, but with low penetration depth of its thermal energy.^1,2 This property yields a low rate of deep dissections, as demonstrated by intravascular ultrasound (IVUS).³ In the EX-PAD-03 investigational device exemption (IDE) study, the Auryon system had a very low rate of acute dissections and bailout stenting, a high procedural success rate, and a low target-lesion revascularization (TLR) rate at 6 months.^4,5 In addition, the laser has a built-in aspiration system in the larger 2.0 mm and 2.35 mm catheters, with no distal embolization reported.⁴ Long-term, real-world data are currently not available for the Auryon laser. In this study, we analyze major adverse events (MAEs) and 6-month outcomes with the Auryon laser system in treating infrainguinal arterial disease in a consecutive series of patients treated at a single center.

Methods

Consecutive patients treated with the Auryon laser between September 2017 and March 2021 were retrospectively reviewed from a single operator at a single center (NWS). The study was approved by the WIRB, a central institutional review board. Demographic, procedural, angiographic, and outcome data were extracted from patients’ medical records. The study’s primary endpoint was the assessment of freedom from TLR at 6-month follow-up. Secondary endpoints included acute procedural results, distal embolization, bailout stenting (dissection type D or higher by National Heart, Lung, and Blood Institute [NHLBI] classification and/or residual narrowing >30%), unplanned major amputation, death, or vascular complications.

Descriptive analysis was performed.  Statistics were presented as mean ± standard deviation (median) and count/N (%) for quantitative and qualitative data, respectively, per patient, per procedure, or per lesion. Follow-up analysis for freedom from TLR rate was count/N (%), where “N” was defined as number of procedures at risk for index procedure, at days 1-30, or at days 31-180. Analysis was performed with Minitab 2020 and Cytel 11 software.

Results

Table 1 shows the demographics of patients enrolled. A total of 56 patients (65 procedures, 70 lesions) were enrolled. The mean patient age was 70.9 ± 10 years, with 66.1% males, 48.2% diabetics, and 25% with limb ischemia. Table 2 shows the procedural and angiographic variables. Of the 70 lesions, 31.4% had severe calcification, 38.6% were chronic total occlusions, and 48.6% were de novo disease (in-stent restenosis in 28.6%). The majority of treated vessels were femoropopliteal (88.6%) and 29.2% had 2 or more prior interventions. Stenosis at baseline was 91.3 ± 9.7%, stenosis post laser was 56.0 ± 17.3%, and stenosis post final treatment was 11.4 ± 11.2%. Lesion length was 117.1 ± 101.2 mm and treated length was 174.0 ± 116.0 mm. Bailout stenting occurred in 11/70 lesions (15.7%). Post laser, there was no NHLBI class D dissection; post laser plus percutaneous transluminal angioplasty, there was 1 class D dissection. Drug-coated balloon (DCB) usage was 47.1% Lutonix (BD/Bard), 27.1% In.Pact (Boston Scientific), and 1.4% both. The details of the laser procedure are shown in Table 3.

In-hospital and 6-month adverse events are detailed in Table 4. There were 63 procedures eligible for follow-up at 6 months.  Death occurred in 2/56 patients (3.6%), with neither death attributable to the procedure. Major amputation rate per procedure was 1/63 (1.6%) and occurred within the first 6 months of follow-up (on day 85 post procedure). Probability of freedom from TLR rate per procedure was 95.6% at 6 months.

Discussion

The Auryon laser is a new laser system with a long wavelength and short pulse width^1,2 and was recently approved by the Food and Drug Administration for the treatment of infrainguinal arterial disease, including in-stent restenosis. In the EX-PAD-03 IDE trial,⁵ TLR rate was very low at 3.3% even though only 60% of lesions were treated with drug-coated balloons. Similarly, the Auryon SCE study showed a TLR rate of 4.8% at 6 months despite the inclusion of more complex, consecutive real-world lesions. Recent data suggest that the Auryon laser has a low rate of deep dissections³ and the overall bailout stenting rate was low. Adventitial damage has been linked to an increase in TLR and restenosis.^6,7 It is possible that sparing the adventitia has contributed to less restenosis and the need for TLR in the short term.

The Auryon laser results in low distal embolization. In the IDE study, distal embolization did not occur despite a very low rate of embolic filter use.⁴ In this study, clinically significant macroembolization (2 mm or more)⁸ was not detected in the filters used. Also, there was only 1 distal embolization that required a simple aspiration to treat. The low rate of macrodebris is likely secondary to the aspiration system that is built in the larger (2.0 and 2.35 mm) Auryon catheters. Finally, no perforation was seen, which was likely because of the shallow penetration of the thermal energy of the Auryon laser sparing the deeper layer of the arteries.

Study limitations. This study is retrospective and therefore selection bias of patients may have occurred. This seems to be unlikely, however, given the complexity of the lesions included. Also, in this retrospective study, there was no core lab adjudication of the angiographic findings. Finally, the data presented include 6-month follow-up and long-term follow-up remains unclear. Prospective, long-term data are needed to verify these findings. The Pathfinder I (ClinicalTrials.gov identifier NCT04229563), a prospective real-world registry of the Auryon laser in femoropopliteal disease, is currently in its follow-up phase and complete data from this study will soon be available. Finally, randomized trials are needed to determine whether the Auryon laser is superior to angioplasty or stenting with or without antiproliferative therapy in treating femoropopliteal arterial disease.

Affiliations and Disclosures

From ¹the Midwest Cardiovascular Research Foundation, Davenport, Iowa; and ²Angiodynamcis, Inc, Latham, New York.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Shammas receives educational and research grants from Angiodynamics, Boston Scientific, Bard/BD, VentureMed Group, and Philips; speakers’ bureau for Janssen, Eli Lilly, Esperion, Boehringer Ingelheim, and Kiniksa. Dr Shankarraman is an employee of Angiodynamics. The remaining authors report no conflicts of interest regarding the content herein.

Manuscript accepted November 29, 2021.

Address for correspondence: Nicolas W. Shammas, MD, MS, FACC, Research Director, Midwest Cardiovascular Research Foundation, 630 East 4th Street, Davenport, IA 52803. Email: shammas@mchsi.com

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