Prospective, Multi-center, Single-Arm Study of the Auryon Laser System for Treatment of Below-the-Knee Arteries in Patients With Chronic Limb-Threatening Ischemia: 30-Day Results of the Auryon BTK.

The 355 nm Auryon laser (AngioDynamics, Inc., Latham, New York) has been shown to be effective and safe in treating various morphology lesions in the femoropopliteal arteries. There are limited data on the Auryon laser in treating below-the-knee (BTK) arteries in patients with chronic limb-threatening ischemia. We present the 30-day efficacy and safety findings from the ongoing Auryon BTK study. Patients with chronic limb-threatening ischemia were prospectively enrolled in the Auryon BTK study between March 2022 and February 2023 in 4 US centers after obtaining written informed consent. The primary safety end point included major adverse limb events + postoperative death at 30 days, defined as a composite of all-cause death, major amputation, and target vessel revascularization. Demographic, procedural, angiographic, and outcome data were collected. A total of 60 patients (61 lesions) were treated. The mean age was 74.6 ± 10.3 years, with 65.0% men, 58.3% with diabetes, 43.3% Rutherford Becker (RB) IV, and 56.7% RB V. Of the 61 lesions, 59% had severe calcification, 31.1% were chronic total occlusions, and 90.2% were de novo disease. The baseline diameter stenosis was 80.2 ± 16.4%, after laser 57.4 ± 21.7%, and after final treatment 24.0 ± 23.1% (p <0.0050). The primary performance end point showed a procedure success rate of 37 of 68 (63.8%). Bailout stenting occurred in 1 of 61 lesions (1.6%). The RB category was 100% RB IV or higher at baseline versus 35.3% at 30 days. At 30 days, there was no target vessel revascularization and the patency was 88.9% (Peak Systolic Velocity Ratio (PSVR) ≤2.4). In conclusion, the Auryon laser is safe and relatively effective in treating BTK lesions with minimal complications.

Intravascular Ultrasound Assessment and Correlation With Angiographic Findings of Arterial Dissections Following Auryon Laser Atherectomy and Adjunctive Balloon Angioplasty: Results of the iDissection Auryon Laser Study.

BACKGROUND: Femoropopliteal arterial angiographic dissections with the use of the Auryon laser atherectomy system (previously the B-laser) have been infrequent and non-flow limiting. However, the pattern of these dissections (depth and arc) using intravascular ultrasound remains unknown. MATERIALS AND METHODS: We prospectively enrolled 29 patients in the iDissection Auryon study. The primary objective was to define the occurrence of new adventitial injury with intravascular ultrasound (IVUS). Secondary objectives included distal embolization and bailout stenting as judged by the operator because of 30% or more residual narrowing and/or NHLBI (National Heart, Lung, and Blood Institute) angiographic dissection C and higher. Core laboratory analysis was carried on all cases except for 1 patient (that crossed over to Jetstream atherectomy). Dissections were classified according to the iDissection classification as involving the intima (A), media (B), and adventitia (C) and ≤ 180-° arc (1) or >180-° arc (2). Overall, 22 of 29 patients had an embolic filter (per protocol). RESULTS: Median lesion and treated lengths were 100.0 and 150.0 mm, respectively. Vessel diameter by IVUS was 6.5 ± 1.5 mm. Chronic total occlusion (CTO) was present in 24.1% of cases. The arc of calcium was: no calcium in 27.6%, <90° in 13.8%, 90° to 180° in 20.7%, and >180° in 34.4%. Lesion severity was reduced to a median of 14% post laser and adjunctive percutaneous transluminal angioplasty (PTA) from a baseline of 76%. Bailout stenting occurred in 6 of 28 (21.4%) patients (3 for dissections, 2 for residual >30%, and 1 for both) and primary stenting in 1 of 28 (3.6%). By IVUS, there were 9 new dissections post laser (1 adventitial; 3≥180°) and 21 new dissections post laser and PTA (3 adventitial; 1≥180°). No distal embolization requiring treatment was seen and no macrodebris ≥2 mm was recovered in the filters. CONCLUSION: The Auryon laser atherectomy system had minimal rate of adventitial injury despite complex disease with relatively low bailout stent rate and no clinically significant macrodebris.

Optimal Vessel Sizing and Understanding Dissections in Infrapopliteal Interventions: Data From the iDissection Below the Knee Study.

PURPOSE: To investigate if imaging with intravascular ultrasound (IVUS) yields a more accurate estimate of vessel diameter and the presence of dissections than angiography after intervention in the infrapopliteal arteries. MATERIALS AND METHODS: A prospective, single-center study enrolled 20 consecutive patients (mean age 74.1±12.4 years; 12 women) with infrapopliteal disease who were treated with percutaneous transluminal angioplasty (PTA; n=10) or orbital atherectomy (OA) followed by PTA (n=10). The majority of patients were hypertensive and half were diabetic. The overall lesion length was 7.3±6.3 cm, and the diameter stenosis was 80.3%±22.1%. The baseline characteristics did not differ between the groups. Vessel diameters were measured using IVUS from the internal elastic lamina (IEL) to the IEL. IVUS was performed at baseline, post PTA or OA, and post OA+PTA. Quantitative vascular angiography (QVA) and IVUS were analyzed by a core laboratory. Dissections on cine images were categorized based on the National Heart Lung and Blood Institute (NHLBI) classification, while the arc and depth were used to characterize dissections on IVUS images. RESULTS: Mean vessel diameter by QVA was 2.9±0.6 vs 4.0±1.0 mm by IVUS according to the core laboratory (mean difference 1.1±0.9, p<0.001). On angiography, there were 7 dissections after PTA (6 C, 1 D), 1 dissection after OA (1 B), and 2 dissections after OA+PTA (1 A, 1 B; p=0.028 vs post PTA). IVUS uncovered 3.8 times more dissections than seen on angiography. There were 23 dissections after PTA (18 intima, 3 media, 2 adventitia), 12 dissections after OA (8 intima, 1 media, 3 adventitia), and 11 dissections following OA+PTA (7 intima, 1 media, 3 adventitia; p=0.425 vs PTA). Bailout stenting (all due to angiographic dissections ≥C) was necessary in 6 of the PTA cohort and none of the OA+PTA group. CONCLUSION: In addition to underestimating the infrapopliteal vessel diameter by ~25%, angiography underappreciated the presence and severity of post-intervention dissections vs IVUS, particularly in the OA+PTA group.

Location of Dissections Post Balloon Angioplasty in Patients With Femoropopliteal Arterial Disease as Seen on Intravascular Ultrasound.

We reviewed images from our intravascular ultrasound core lab to define the various locations of dissections in femoropopliteal arteries post balloon angioplasty in relation to plaque morphology.

Intravascular Ultrasound Assessment and Correlation With Angiographic Findings Demonstrating Femoropopliteal Arterial Dissections Post Atherectomy: Results From the iDissection Study.

BACKGROUND: Dissections occur post atherectomy of the infrainguinal arteries. We hypothesized that angiography under-estimates their presence significantly. METHODS: In this prospective pilot study, a total of 15 patients were evaluated by intravascular ultrasound (IVUS) following treatment of femoropopliteal de novo or non-stent restenosis using atherectomy. Eagle Eye Platinum ST IVUS catheters (Philips) were used in this study. Thirteen Jetstream XC atherectomy devices (Boston Scientific) and 2 investigational B-laser atherectomy devices (Eximo Medical) were used. Cine and IVUS images were obtained at baseline, after atherectomy, and after adjunctive balloon angioplasty. Angiographic and IVUS core labs analyzed the images. RESULTS: Mean age was 70.6 ± 8.0 years. Diabetes and claudication were present in 60% and 73%, respectively. Mean baseline, post-atherectomy, and post-adjunctive angioplasty stenosis severity was 71.4%, 38.1%, and 19.7%, respectively (P<.001 for both baseline vs post atherectomy and post atherectomy vs adjunctive angioplasty). Lesion length was 108.5 ± 43.1 mm. Forty-six dissections were identified on IVUS post atherectomy vs 8 dissections on angiogram (P<.01) (ratio, 5.75 to 1). Post adjunctive angioplasty, there were 39 dissections on IVUS vs 11 on angiogram (P<.01) (ratio, 3.55 to 1). Of these dissections, 13% and 30.8% were ≥180° in circumference post atherectomy and adjunctive balloon angioplasty, respectively (P=.047). Also, 39.1% and 33.3% involved the media and/or adventitia as seen on IVUS post atherectomy and adjunctive balloon angioplasty, respectively (P=.58). Longer lesions correlated with more dissections post atherectomy on IVUS (P=.03), but not on angiogram (P=.28). CONCLUSION: Dissections post atherectomy are grossly under-appreciated on angiogram when compared to IVUS. A multicenter registry correlating these findings with clinical outcomes is needed.

Dissections in Peripheral Vascular Interventions: A Proposed Classification Using Intravascular Ultrasound.

Dissections following interventions in the infrainguinal arteries occur very frequently and are mostly under-appreciated on angiographic imaging. Media and external elastic lamina injury can contribute to loss of patency, and intravascular ultrasound (IVUS) can identify this type of injury. The circumference of injury also has been proposed to be a predictor of outcome. We therefore propose a classification combining depth of injury from intima to adventitia with circumference of dissection. This classification exhibits six dissection grades (A1, A2, B1, B2, C1, and C2) as seen on IVUS (the "iDissection" classification).