How Much Debulking with Atherectomy is Enough When Treating Infrainguinal Arterial Interventions? The Balance Between Residual Stenosis and Adventitial Injury

Atherectomy - The Options, the Evidence, and When Should It Be Used

The use of atherectomy for peripheral vascular interventions (PVIs) has increased exponentially and reached 18% of all PVI in the United States. The theoretical benefit on extensive arterial calcification relies on the concept of plaque modification and removal instead of displacement, as with other endovascular techniques. To date, there are no prospective studies comparing the different atherectomy technologies (directional, rotational, orbital, and laser). Moreover, most related prospective comparative studies have a small number of patients, and larger studies are single arm in patients with relatively mild to moderate disease burden. While available literature shows lower dissection risk and reduced bailout stenting, the superiority of this technology compared to other endovascular techniques has yet to be proven. Despite the lack of level 1 evidence to support its superiority, the lucrative reimbursement fueled the overuse of this technology as first-line therapy, particularly in office-based laboratories and ambulatory surgery centers. The use of atherectomy ought to be selective and complementary to other endovascular technologies, and individualized patient-level decision-making based on the practitioner's preference and expertise is essential to selectively incorporate atherectomy in managing complex atherosclerotic lesions.

Intravascular Ultrasound Assessment of Arterial Dissections Following Rotarex Atherectomy: Results of the iDissection Rotarex Study

Background

There are limited data on the mechanism of the Rotarex Rotational Excisional Atherectomy System in treating femoropopliteal arterial disease. The Rotarex iDissection study is a prospective, single center study evaluating the extent of excision and dissection in de novo and restenotic (not in-stent) lesions of the femoropopliteal arteries in symptomatic peripheral arterial disease patients.

Methods

Consecutive patients with symptomatic peripheral arterial disease were prospectively enrolled in the Rotarex iDissection study at a single US center after obtaining informed consent. The study was approved by a central ethics committee. Quantitative vascular angiography and intravascular ultrasound images were analyzed by an independent core laboratory. The Eagle Eye Platinum ST intravascular ultrasound (Phillips) was used to identify the depth (A, B, C for intima, media, and adventitia, respectively) and arc of dissections (1 and 2 for <180° and ≥180°, respectively) using the iDissection classification. Statistical significance was determined by a P value <.05.

Results

A total of 19 patients (20 procedures) were enrolled by 1 endovascular specialist. There were 57.9% men with mean age of 71.1 ± 9.6 years. Of the patients, 31.6% had diabetes mellitus, and 84.2% were current or past smokers. Thirty percent of treated vessels were chronic total occlusions. A total of 10 patients received stents (2 covered stents due to perforation, 6 due to National Heart, Lung, and Blood Institute Type C dissections, and 2 were primary stenting). Two distal embolizations occurred; one was attributed to the Rotarex, and both were treated with no adverse consequences. Angiographic baseline stenosis was 74.7% ± 25.6%; after Rotarex, 48.7% ± 14.8%; and after percutaneous transluminal angioplasty (PTA), 16.0% ± 6.2%. Baseline minimal lumen diameter was 1.0 ± 1.0 mm; after Rotarex, 2.4 ± 1.1 mm; and after PTA, 4.4 ± 1.0 mm. Angiographically, there was 1 type A dissection at baseline; 1 A, 1 B, and 2 C after Rotarex, and 3 A and 5 C after final adjunctive PTA. Intravascular ultrasound revealed a reference diameter of 6.2 ± 1.0 mm; 70% of patients had adventitial dissections. The mean arc of calcium was 221° ± 39.4° (moderate to severe calcium).

Conclusions

The Rotarex device is an effective atherectomy device in treating complex femoropopliteal arterial disease. A high frequency of adventitial dissections is seen with the Rotarex. The long-term outcomes of this finding need to be further studied.

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.

Treatment effect of medial arterial calcification in below-knee after Auryon laser atherectomy using micro-CT and histologic evaluation

PURPOSE

To determine the frequency of medial arterial calcification (MAC) fracture following Auryon laser atherectomy using micro-CT and histologic evaluation in an atherosclerotic human cadaveric limb model.

METHODS

Two below-the-knee calcified arterial segments from human cadaver limbs underwent treatment with the Auryon laser system with or without plain old balloon angioplasty (POBA). Micro-CT and angiography were performed before and after treatment followed by histological evaluation of regions showing calcium disruption.

RESULTS

All treatment zones were successfully treated with the Auryon laser (n = 9). Six of 9 treatment zones showed calcium fracture on micro-CT. Each treatment zone was further subdivided using micro-CT analysis (36 evaluated sections) of which 18 sections revealed calcium fracture. Sections with calcium fracture had significantly more confluent and uninterrupted circumferential calcification than sections without calcium fracture (arc of calcification 360.0 [323.7-360.0] vs 312.8 [247.4-314.2] degree, p = 0.007), whereas there were no differences in size of calcium burden (3.4 [2.8-3.9] vs 2.8 [1.3-4.6] mm2, p = 0.46). No arterial dissection or rupture was seen.

CONCLUSIONS

Auryon laser atherectomy produced fractures of medial arterial calcification in this cadaveric human atherosclerotic peripheral artery model. This effect was observed in arterial segments with a pattern of circumferential uninterrupted calcification (i.e. larger arc of calcification) regardless of calcium burden. Our pilot data suggests Auryon laser may be a promising therapy for calcified lesions.