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.

Intravascular ultrasound guidance for lower extremity arterial and venous interventions

This review details the utility of intravascular ultrasound (IVUS) for the management of peripheral artery and venous disease. The purpose of this document is to provide an update in the use of IVUS in peripheral arterial and venous pathology and demonstrate the use of IVUS as a practical diagnostic imaging procedure to evaluate and treat peripheral vascular disorders. IVUS, a diagnostic tool that relies on sound waves to produce precise images of the vessel being evaluated, was originally introduced to the medical community for the purposes of peripheral artery imaging, though it was quickly adapted for coronary interventions with positive outcomes. The utility of IVUS includes vessel measurement, pre- and post-procedural planning, treatment optimisation, and detection of thrombus, dissection or calcium severity. While angiography remains the standard imaging approach during peripheral intervention, multiple observational studies and small prospective trials have shown that in comparison, IVUS provides more accurate imaging detail, which may improve procedural outcomes. IVUS can also address limitations of angiography, including the need to administer contrast medium and eliminate the ambiguity associated with other forms of imaging. This review provides contemporary examples of where IVUS is being used during peripheral intervention as well as representative imaging to serve as a resource for the practising clinician.

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

Atherectomy is an effective vessel prepping device but not all atherectomy devices are equal. The depth of vessel injury and residual narrowing vary considerably among atherectomy devices with significant implications on outcome. Precision imaging is critical to optimize outcome using atherectomy as a vessel prepping technique. Prospective trials need to test the hypothesis that precision imaging has a significant impact on how operators approach the treatment of infrainguinal arterial disease.

Early Adventitial Activation and Proliferation in a Mouse Model of Arteriovenous Stenosis: Opportunities for Intervention

Background: Arteriovenous fistula (AVF) stenosis remains an important cause of AVF maturation failure, for which there are currently no effective therapies. We examined the pattern and phenotype of cellular proliferation at different timepoints in a mouse model characterized by a peri-anastomotic AVF stenosis. Methods: Standard immunohistochemical analyses for cellular proliferation and macrophage infiltration were performed at 2, 7 and 14 d on our validated mouse model of AVF stenosis to study the temporal profile, geographical location and cellular phenotype of proliferating and infiltrating cells in this model. Results: Adventitial proliferation and macrophage infiltration (into the adventitia) began at 2 d, peaked at 7 d and then declined over time. Surprisingly, there was minimal macrophage infiltration or proliferation in the neointimal region at either 7 or 14 d, although endothelial cell proliferation increased rapidly between 2 d and 7 d, and peaked at 14 d. Conclusions: Early and rapid macrophage infiltration and cellular proliferation within the adventitia could play an important role in the downstream pathways of both neointimal hyperplasia and inward or outward remodelling.

Clinical Outcomes of Atherectomy Plus Drug-coated Balloon Versus Drug-coated Balloon Alone in the Treatment of Femoropopliteal Artery Disease

Drug-coated balloons (DCBs) emerged as an attractive treatment option for femoropopliteal artery disease. However, achieving the best outcome with DCB needed proper vessel preparation. Thus, the reduction and modification of atherosclerotic plaques by atherectomy were suggested. This study investigated the efficacy of atherectomy in native femoropopliteal artery disease compared with DCB alone using two-center cohorts. As a result, the pretreatment with atherectomy improved the technical success of DCB treatment; however, it was associated with increased minor complications. Additionally, atherectomy plus DCB showed no clinical benefit regarding TLR-free survival or clinical patency compared with DCB treatment alone.

Background and Objectives

Atherectomy as a pretreatment has the potential to improve the outcomes of drug-coated balloon (DCB) treatment by reducing and modifying atherosclerotic plaques. The present study investigated the outcomes of atherectomy plus DCB (A+DCB) compared with DCB alone for the treatment of femoropopliteal artery disease.

Methods

A total of 311 patients (348 limbs) underwent endovascular therapy using DCB for native femoropopliteal artery lesions at two endovascular centers. Of these, 82 limbs were treated with A+DCB and 266 limbs with DCB alone. After propensity score matching based on clinical and lesion characteristics, a total of 82 pairs was compared for immediate and mid-term outcomes.

Results

For the matched study groups, the lesion length was 172.7±111.2 mm, and severe calcification was observed in 43.3%. The technical success rate was higher in the A+DCB group than in the DCB group (80.5% vs. 62.2%, p=0.015). However, the A+DCB group showed more procedure-related minor complications (37.0% vs. 13.4%, p=0.047). At 2-year follow-up, primary clinical patency (73.8% vs. 82.6%, p=0.158) and the target lesion revascularization (TLR)-free survival (84.3% vs. 88.2%, p=0.261) did not differ between the two groups. In Cox proportional hazard analysis, atherectomy showed no significant impact on the outcome of DCB treatments.

Conclusions

The pretreatment with atherectomy improved technical success of DCB treatment; however, it was associated with increased minor complications. In this study, A+DCB showed no clinical benefit in terms of TLR-free survival or clinical patency compared with DCB treatment alone.

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.

IVUS-Guided Wiring Improves the Clinical Outcomes of Angioplasty for Long Femoropopliteal CTO Compared with the Conventional Intraluminal Approach

AIMS

This study aimed to assess the clinical efficacy of intravascular ultrasound (IVUS)-guided intraplaque wiring for femoropopliteal (FP) chronic total occlusion (CTO).

METHODS

This single-center, retrospective, observational study was performed at the Japanese Red Cross Kyoto Daini Hospital. From March 2013 to June 2017, a total of 75 consecutive patients (mean age: 75.4±8.5 years; 59 males), who underwent endovascular treatment (EVT), having 82 de novo FP-CTO lesions, were enrolled in this study. Eleven of the lesions that met the exclusion criteria were excluded, and the remaining 71 lesions were divided into the IVUS-guided wiring group (n=34) and non-IVUS-guided wiring group (n=37). Primary patency, defined as a peak systolic velocity ratio of ＜2.4 on duplex ultrasonography, and freedom from clinically driven target lesion revascularization (CD-TLR) at 12 months were the primary outcomes.

RESULTS

The mean lesion length was 21.6±8.9 cm. The frequencies of primary patency and freedom from CD-TLR were significantly higher in the IVUS-guided wiring group than in the non-IVUS-guided wiring group (70.0% vs. 52.2%, p=0.045; 83.9% vs. 62.8%, p=0.036, respectively). The complete clinically true lumen angioplasty rate was also higher in the IVUS-guided wiring group than in the non-IVUS-guided wiring group (91.1% vs. 51.3%, p＜0.001, respectively). The clinically true and false wire passage rates were respectively 97.3% and 2.7% in the IVUS-guided wiring group.

CONCLUSION

IVUS-guided wiring improves the clinical outcomes of EVT for FP-CTO by achieving a high clinically true lumen wire passage rate.

Safety and outcomes of combined carbon dioxide angiography and OCT-guided femoro-popliteal chronic total occlusion crossing and directional atherectomy in patients with chronic kidney disease

BACKGROUND

Carbon dioxide angiography with addition of optical coherence tomography imaging may improve procedural success and clinical outcomes in patients with peripheral artery disease and chronic kidney disease.

METHODS

Single-center, retrospective analysis of patients with chronic kidney disease who underwent carbon dioxide angiography and optical coherence tomography-guided chronic total occlusion crossing and/or optical coherence tomography-guided directional atherectomy was performed. Patient and procedure-related characteristics, along with peri- and one-year post-procedural major adverse events, were analyzed.

RESULTS

A total of 18 vessels in 11 patients, with mean age 70 years were treated. All had co-morbidities such as hypertension, hyperlipidemia, had history or were current smokers with baseline peripheral artery disease. Majority were diabetic with coronary disease (82%); 55% baseline chronic kidney disease IV, 55% Rutherford class III and 45% class IV. Contrast was used in only two patients. Mean total fluoroscopy time and radiation dose was 24.1 min and 249.2 mGY, respectively. Half of the lesions were femoro-popliteal chronic total occlusions, and Ocelot catheter was used to cross seven of nine chronic total occlusions and was successful in six. Adjunctive optical coherence tomography-guided directional atherectomy was performed in 8 of 11 patients. Only two adverse events occurred: one clinically significant event of slow-flow intra-procedurally and one target limb revascularization within one year of index procedure in a vessel different than prior treated. Optical coherence tomography imaging in both chronic total occlusion-crossing and atherectomy resulted in 10-min mean fluoroscopy reduction time and 32 mGY reduction in radiation dose.

CONCLUSION

Carbon dioxide angiography with the addition of optical coherence tomography imaging for chronic total occlusion crossing and/or optical coherence tomography-guided directional atherectomy reduced the need for contrast agents, total fluoroscopy time, and radiation exposure in patients with peripheral artery disease and baseline chronic kidney disease.

Successful Peripheral Vascular Intervention in Patients with High-risk Comorbidities or Lesion Characteristics

PURPOSE OF REVIEW

Certain comorbidities and lesion characteristics are associated with increased risk for procedural complications, limb events, and cardiovascular events following peripheral vascular intervention (PVI) in patients with peripheral arterial disease (PAD). The purpose of this review is to provide an overview of high-risk modifiable and unmodifiable patient characteristics and its relative impact on clinical outcomes such as amputation risk and mortality. Furthermore, general approaches to potentially mitigating these risks through pre-intervention planning and use of modern devices and techniques are discussed.

RECENT FINDINGS

Diabetes, tobacco use, and older age remain strong risk factors for the development of peripheral arterial disease. Recent data highlight the significant risk of polyvascular disease on major limb and cardiac events in advanced PAD, and ongoing studies are assessing this risk specifically after PVI. Challenging lesion characteristics such as calcified disease and chronic total occlusions can be successfully treated with PVI by utilizing novel devices (e.g., intravascular lithotripsy, re-entry devices) and techniques (e.g., subintimal arterial "flossing" with antegrade-retrograde intervention). Understanding high-risk patient comorbidities and lesion characteristics will improve our ability to counsel and manage patients with advanced PAD. Continued device innovation and novel techniques will aid in procedural planning for successful interventions to improve clinical outcomes.

Excimer laser atherectomy in complex peripheral artery disease: a prospective European registry

BACKGROUND

This study aimed to investigate performance, effectiveness, and safety of excimer laser atherectomy for the treatment of complex lower limb artery disease in a real-world setting.

METHODS

In our prospective, multicenter registry, consecutive patients with complex lower limb lesions underwent excimer laser atherectomy with optional standard balloon angioplasty, paclitaxel-coated balloon angioplasty, and bailout stenting. Primary outcome was technical success. Secondary outcomes were device performance of the excimer laser system, freedom from target lesion revascularization (TLR), peri-procedural complications, and amputation-free survival in patients with critical limb ischemia (CLI).

RESULTS

A total of 294 patients were enrolled at 14 European centers (mean lesion length 109±103 mm, total occlusions 56.8% [167 of 294 lesions], CLI 47.3% [132 of 279 patients]. Adjuvant balloon angioplasty was conducted in 283 (96.3%), and complementary stent implantation in 98 patients (33.3%). Technical success was achieved in 95.3% of patients. Increasing lesion length was associated with decreased laser atherectomy performance (odds ratio [OR] per 10 mm: 0.94 [95% confidence interval [CI] 0.90 to 0.99], P=0.01). A total of 66 patients (22.4%) completed the 12-month follow-up. Freedom from TLR was 83.5% (95% CI: 74.9 to 92.1) at 12 months. Chronic total occlusions were associated with more TLR (OR 5.03 [95% CI: 1.01 to 25.1], P=0.049). Amputation -free survival in patients with CLI was 93.1% (95% CI: 83.9 to 100).

CONCLUSIONS

Excimer laser atherectomy substantially contributed to technical success of endovascular treatment of complex infra-inguinal lesions. Freedom from 12-month TLR was reasonable.

Usefulness of ultrasound-guided intraluminal approach for long occlusive femoropopliteal lesion

To investigate the usefulness of ultrasound-guided (USG) intraluminal approach for femoropopliteal (FP) lesion. 64 patients (73 limbs) with de novo long occlusive (> 15 cm) FP lesions underwent USG intralumial approach from April 2012 to October 2016. Periprocedural intravascular ultrasound findings were collected. Clinical outcome and predictors of restenosis after USG intraluminal approach for de novo long occlusive FP lesion were investigated. Among the study participants, 34% were female, 50% had diabetes mellitus, and 10% received hemodialysis. Lesion and chronic total occlusion (CTO) lengths were 222 ± 55 mm and 201 ± 55 mm, respectively. Procedural success was achieved in 72 lesions (99%). Distal puncture was performed in 7 limbs (10%). The proportion of within-CTO intraplaque, subintimal, and medial routes were 87 ± 21%, 9 ± 15%, and 4 ± 11%, respectively. Primary patency was 71% and 69% at 1 and 2 years. Multivariate analysis revealed that within-CTO intraplaque route proportion [hazard ratio (HR) 0.81; 95% confidence interval (CI) 0.67-0.98, p = 0.0339] and lesion length (HR 1.11; CI 1.00-1.22; p = 0.0447) were independent predictors of restenosis.USG intraluminal approach facilitated acquisition of within-CTO intraplaque route in long occlusive FP lesions and could improve clinical outcome.

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.

Superficial Femoral Artery Pseudoaneurysm as a Delayed Complication of TurboHawk Atherectomy

BACKGROUND

Peripheral atherectomy is utilized in the treatment of heavily calcified plaques from peripheral arterial lesions. Commonly reported complications include access site injury, perforations, dissections, embolism, and retroperitoneal hemorrhage.

METHODS

We report the case of a 74-year-old Caucasian male who developed a 50 × 43 × 40-mm saccular pseudoaneurysm in the native mid-superficial femoral artery after TurboHawk atherectomy.

RESULTS

We describe the diagnostic steps in identifying this complication secondary to directional atherectomy and the successful treatment of this pseudoaneurysm using a Viabahn stent graft.

CONCLUSIONS

Pseudoaneurysm is a rare complication associated with the procedure which must be followed up with repeat imaging. Symptoms such as limb pain or swelling or increase in the size of pseudoaneurysm should prompt timely assessment of atherectomy site. Stenting with a Viabahn stent has proven to be a viable and successful treatment option.

A post-market, multi-vessel evaluation of the imaging of peripheral arteries for diagnostic purposeS comparing optical Coherence tomogrApy and iNtravascular ultrasound imaging (SCAN)

Background

Intravascular imaging plays an important part in diagnosis of vascular conditions and providing insight for treatment strategy. Two main imaging modalities are intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The objective of this study was to prove non-inferiority of OCT imaging to IVUS images in matched segments of peripheral vessels in patients with suspected peripheral vascular disease.

Methods

The SCAN study was a prospective, non-inferiority clinical study of matched IVUS and OCT images collected along defined segments of peripheral vessels from twelve subjects (mean age 68 ± 10.3 years; 10 men) displaying symptoms of vascular disease. Luminal diameters were measured by both imaging systems at the distal, middle, and proximal points of the defined segments. Three blinded interventional radiologists evaluated the quality of both imaging modalities in identifying layered structures (3-point grading), plaque (5-point grading), calcification (5-point grading), stent structure (3-point grading), and artifacts (3-point grading) from 240 randomly ordered images. Mean grading scores and luminal diameters were calculated and analyzed with Student’s t-Test and Mann-Whitney-Wilcoxon testing. Intrareader reproducibility was calculated by intraclass correlation (ICC) analysis.

Results

The mean scoring of plaque, calcification, and vascular stent struts by the three readers was significant better in terms of image quality for OCT than IVUS (p < 0.001, p = 0.001, p = 0.004, respectively). The mean scores of vessel wall component visibility and artifacts generated by the two imaging systems were not significantly different (p = 0.19, p = 0.07, respectively). Mean vessel luminal diameter and area at three specific locations within the vessels were not significantly different between the two imaging modalities. No patient injury, adverse effect or device malfunction were noted during the study.

Conclusions

Imaging by OCT provides the physician with better visualization of some vessel and plaque chacteristics, but both IVUS and OCT imaging are safe and effective methods of examining peripheral vessels in order to perform diagnostic assessment of peripheral vessels and provide information necessary for the treatment strategy of peripheral artery disease.

Trial registration

NCT03480685 registered on 29 March 2018.

The role of precise imaging with intravascular ultrasound in coronary and peripheral interventions

Angiography remains a widely utilized imaging modality during vascular procedures. Angiography, however, has its limitations by underestimating the true vessel size, plaque morphology, presence of calcium and thrombus, plaque vulnerability, true lesion length, stent expansion and apposition, residual narrowing post intervention and the presence or absence of dissections. Intravascular ultrasound (IVUS) has emerged as an important adjunctive modality to angiography. IVUS offers precise imaging of the vessel size, plaque morphology and the presence of dissections and guides interventional procedures including stent sizing, assessing residual narrowing and stent apposition and expansion. IVUS-guided treatment has shown to yield superior outcomes when compared to angiography-only guided therapy. The cost-effectiveness of the routine use of IVUS during vascular procedures needs to be further studied.

How to deal with calcium in the superficial femoral artery

Despite the continuous evolution of endovascular therapy, severe calcification remains a major issue for the minimally invasive treatment of superficial femoral artery (SFA) disease. The presence of calcium might negatively affect both the crossing of peripheral lesions and outcomes of all available treatment modalities and is therefore associated with unfavorable acute and long-term results. This manuscript summarizes the challenges raised from severe calcified atherosclerotic lesions and presents the outcomes of the various endovascular modalities in the treatment of calcified SFA disease.

Directional atherectomy with antirestenotic therapy for the treatment of no-stenting zones

Endovascular treatment for peripheral artery occlusive disease carries unresolved problem of restenosis. Treatment modalities in areas of high mechanical stress like popliteal artery and common femoral artery remains challenging. New-generation devices improved the results of stent therapy in this anatomical territory, but could impact on future surgical options if they are needed. Vessel preparation prior to drug (paclitaxel)-coated balloons (DCB) angioplasty leads to better paclitaxel penetration into the arterial wall and improved drug uptake. The "leave nothing behind" strategies, DCB angioplasty and combined directional atherectomy (DA) and antirestenotic therapy (DAART), can theoretically overcome the problems caused by the mobility of the knee joint. However, calcified and longer lesions remain a challenging subset that is less responsive to DCBs, resulting in higher provisional stent rates. For the treatment of long and calcified femoropopliteal lesions, vessel preparation with DA before DCB angioplasty seems to be safe in mid-term follow-up and might have benefits in more challenging lesion subsets that are at higher risk for acute and chronic technical treatment failure of percutaneous transluminal angioplasty, including DCB angioplasty, such as severely calcified lesions. Treatment with DA+DCB resulted in both increased technical success and fewer flow-limiting dissections compared with treatment with DCB alone. In concept of "leave nothing behind" therapies for isolated popliteal artery lesions, DAART was associated with a higher primary patency rate than DCB angioplasty alone.

Intravascular ultrasound guided directional atherectomy versus directional atherectomy guided by angiography for the treatment of femoropopliteal in-stent restenosis

BACKGROUND

The aim of this study was to compare 1-year outcomes for patients with femoropopliteal in-stent restenosis using directional atherectomy guided by intravascular ultrasound (IVUS) versus directional atherectomy guided by angiography.

METHODS AND RESULTS

This was a retrospective analysis for patients with femoropopliteal in-stent restenosis treated with IVUS-guided directional atherectomy versus directional atherectomy guided by angiography from a single center between March 2012 and February 2016. Clinically driven target lesion revascularization was the primary endpoint and was evaluated through medical chart review as well as phone call follow up.

CONCLUSIONS

Directional atherectomy guided by IVUS reduces clinically driven target lesion revascularization for patients with femoropopliteal in-stent restenosis.

Intravascular ultrasound assessment of the effect of laser energy on the arterial wall during the treatment of femoro-popliteal lesions: a CliRpath excimer laser system to enlarge lumen openings (CELLO) registry study

The CliRpath Excimer Laser System to Enlarge Lumen Openings (CELLO) registry included patients treated with modified excimer laser catheters for the endovascular treatment of peripheral artery disease affecting the superficial femoral artery (SFA) and proximal popliteal artery. The aim of this study was to assess, via intravascular ultrasound (IVUS) the dissections in the vessel wall following treatment with the laser catheters. IVUS grayscale images from the CELLO registry were systematically reviewed for dissections in the treated vessel segments by two investigators. Images from 33 patients; 66 pullbacks (1867 IVUS frames in 2 phases), were successfully matched frame-to-frame to evaluate identical segments of the treated vessels in the two phases; post-2 mm Turbo-Elite laser pilot channel creation and post Turbo-Booster laser atherectomy. Dissections were categorized as; (1) intimal, (2) medial, (3) intramural hematoma, and (4) adventitial according to the ACC Clinical Expert Consensus Document classification of dissections. An average of 57 frames was evaluated per pullback, giving a total of 3734 frames (1867 matched for pre-ablation (post channel creation) and post-ablation phases). Treatments with the modified Excimer laser catheters resulted in a significant increase in lumen area of 5.5 ± 3.2-mm² (95% CI 4.3–6.8, p < 0.0001) and reduction in plaque plus media volume of −10.6 ± 36.0 mm³ (95% CI −25.8 to 4.6, p = 0.1619) whilst giving rise to mainly intramural hematoma formations post Turbo-Booster laser treatment in 55% of frames assessed and 24% medial dissections with less than 1% adventitial disruption. The Excimer laser based Turbo-Booster treatment of peripheral artery lesions resulted in significant plaque debulking and increased lumen diameter with negligible degree of adventitial layer injury.

Lower Extremity Revascularization Using Optical Coherence Tomography-Guided Directional Atherectomy: Final Results of the EValuatIon of the PantheriS OptIcal COherence Tomography ImagiNg Atherectomy System for Use in the Peripheral Vasculature (VISION) Study

PURPOSE

To evaluate the safety and efficacy of a novel optical coherence tomography (OCT)-guided atherectomy catheter in treating patients with symptomatic femoropopliteal disease.

METHODS

The VISION trial ( ClinicalTrials.gov identifier NCT01937351) was a single-arm, multicenter, global investigational device exemption study enrolling 158 subjects (mean age 67.2±10.5 years; 87 men) across 20 participating sites. In this cohort, 198 lesions were treated with an average length of 53±40 mm using the Pantheris catheter alone or Pantheris + adjunctive therapy. The primary safety endpoint was the composite of major adverse events (MAEs) through 6 months (objective performance goal 43.2%). Technical success (primary efficacy outcome) was defined as the percent of target lesions with a residual diameter stenosis ≤50% after treatment with the Pantheris device alone (objective performance goal 87.0%). Procedural success was defined as reduction in stenosis to ≤30% after Pantheris ± adjunctive therapy. Tissue specimens retrieved from each treated lesion were histologically analyzed to evaluate the accuracy and precision of OCT image guidance.

RESULTS

The primary efficacy outcome was achieved in 192 (97.0%) of the 198 lesions treated with the Pantheris catheter. Across all lesions, mean diameter stenosis was reduced from 78.7%±15.1% at baseline to 30.3%±11.8% after Pantheris alone (p<0.001) and to 22.4%±9.9% after Pantheris ± adjunctive therapy (p<0.001). Of the 198 target lesions, 104 (52.5%) were treated with the Pantheris alone, 84 (42.4%) were treated with Pantheris + adjunctive angioplasty, and 10 (5.1%) with Pantheris + angioplasty + stenting. The composite MAE outcome through 6 months occurred in 25 (16.6%) of 151 subjects. There were no clinically significant perforations, 1 (0.5%) catheter-related dissection, 4 (2%) embolic events, and a 6.4% clinically driven target lesion revascularization rate at 6 months. The 40-lesion chronic total occlusion (CTO) subset (mean lesion length 82±38 mm) achieved a similar significant reduction in stenosis to 35.5%±13.6% after Pantheris alone (p<0.001). Histological analysis of atherectomy specimens confirmed <1% adventitia in 82.1% of the samples, highlighting the precision of OCT guidance. Characterization of the OCT-guided lesions revealed evidence of an underestimation of disease burden when using fluoroscopy.

CONCLUSION

OCT-guided atherectomy for femoropopliteal disease is safe and effective. Additionally, the precision afforded by OCT guidance leads to greater removal of plaque during atherectomy while sparing the adventitia.

Directional Atherectomy With Antirestenotic Therapy vs Drug-Coated Balloon Angioplasty Alone for Isolated Popliteal Artery Lesions

Purpose: To report a single-center study comparing drug-coated balloon (DCB) angioplasty vs directional atherectomy with antirestenotic therapy (DAART) for isolated lesions of the popliteal artery. Methods: Seventy-two patients were treated with either DCB angioplasty alone (n=31) or with DAART (n=41) for isolated popliteal artery stenotic disease between October 2009 and December 2015. The majority of patients presented with lifestyle-limiting claudication (74% vs 86%, respectively). Vessel calcification (29% vs 29%, respectively), mean lesion length (47 vs 42 mm, respectively), and number of runoff vessels were comparable between the groups. The primary outcome measure was primary patency; secondary outcomes were technical success (<30% residual stenosis or bailout stenting), secondary patency, and freedom from clinically driven target lesion revascularization (TLR). Results: The technical success rate following DCB was 84% vs 93% (p=0.24) after DAART. The 12-month primary patency rate was significantly higher in the DAART group (65% vs 82%; hazard ratio 2.64, 95% confidence interval 1.09 to 6.37, p=0.021), while freedom from TLR did not differ between the 2 treatment strategies (82% vs 94%, p=0.072). Secondary patency at 12 months was identical for both groups (96% vs 96%). Although not statistically significant, bailout stenting was more common after DCB angioplasty (16% vs 5% for DAART, p=0.13) and aneurysmal degeneration of the popliteal artery was seen more often after DAART (7% vs 0% for DCB alone, p=0.25). Popliteal artery injury was observed in 2 patients treated using DAART (5% vs 0% for DCB alone, p=0.5), whereas distal embolization rates were comparable between the groups (3% for DCB alone vs 5% for DAART, p=0.99). Conclusion: In this study, the use of DAART was associated with a higher primary patency rate compared with DCB angioplasty for isolated popliteal lesions. Nonetheless, both treatment options were associated with excellent 12-month secondary patency. Aneurysmal degeneration of the popliteal artery and increased bailout stenting could compromise the outcomes of DAART and DCB, respectively.

Clinical Outcomes of the Intraluminal Approach for Long Occlusive Femoropopliteal Lesions Assessed by Intravascular Ultrasound

Aim: To investigate the relationship between intravascular ultrasound (IVUS) findings and restenosis after stent implantation for long occlusive femoropopliteal (FP) lesions using the intraluminal approach.

Methods: This was a single-center retrospective study of 45 patients (49 lesions) with de novo long occlusive FP lesions treated with bare metal stents implanted using the intraluminal approach under IVUS guidance from April 2007 to December 2014. All patients were followed up at least 12 months. The preprocedural and postprocedural IVUS findings were compared for patients with and without restenosis, which was defined as a peak systolic velocity ratio of > 2.4 on duplex ultrasonography or > 50% diameter stenosis on angiography.

Results: Within 12 months, 13 patients (14 lesions) developed restenosis, whereas 32 patients (35 lesions) did not (restenosis rate = 29%). The male:female ratio and the prevalence of diabetes mellitus, hemodialysis, and critical limb ischemia were similar between the two groups. No significant differences were observed in lesion length, chronic total occlusion (CTO) length, and the percentage of involving popliteal lesion between the two groups. A whole intraplaque route was gained in 15 lesions (31%). Multivariate analysis revealed that the within-CTO intramedial route proportion and the distal lumen cross-sectional area (CSA) were independent predictors of restenosis. Receiver operating characteristic analysis showed that the best cutoff values of these parameters were 14.4% and 17.7 mm², respectively.

Conclusions: In patients with long occlusive FP lesions undergoing stent placement using the intraluminal approach, a whole intraplaque route was gained in 31%. Restenosis is more likely if IVUS shows a within-CTO intramedial route proportion of > 14.4% or distal lumen CSA of < 17.7 mm².

Ubiquitous Nature of Distal Athero/Thromboembolic Events during Lower Extremity Atherectomy Procedures Involving the Superficial Femoral Artery

This study aims to evaluate occurrence, size, composition, and clinical significance of embolized debris during superficial femoral artery atherectomy using all commercially available atherectomy devices. Distal athero/thromboembolic events (DATE) are a universal phenomenon in lower extremity atherectomy procedures (LEAPs) due to the sheer volume of atheroma and the thrombus burden in peripheral arterial disease. Some of these events can be clinically significant. We prospectively gathered clinical and histopathological data on all commercially available atherectomy devices by using embolic protection devices (EPD) in every case. After intervention, the contents of EPD were examined both microscopically and macroscopically. Data from 59 consecutive patients undergoing LEAP were analyzed. DATE occurred 100% of the time. The composition of particulate debris varied with the device used. Grossly visible agglomerated debris was captured by the filter in the majority of patients 54/59 (91.5%). Clinically significant debris, defined by the Preventing Lower Extremity Distal Embolization Using Embolic Filter Protection registry as particle diameter > 0.2 cm, was found in 33/59 (56%) patients. The size of captured debris particles ranged from 0.1 to 2.4 mm. While DATE occurred in all patients, clinically significant DATE occurred in 56% patients undergoing LEAP regardless of the atherectomy device. In spite of a large fraction of the clinically significant debris occurring on our routine dual antiplatelet regimen, no patient suffered an amputation. Although DATE was prevented by the use of EPD in all 59 cases, more data are needed to determine whether the use of EPD translates into a long-term clinical benefit. Use of EPD and optimal thromboprophylaxis should be considered in patients, especially in the setting of compromised distal runoff.

Immediate and intermediate-term results of optical coherence tomography guided atherectomy in the treatment of peripheral arterial disease: Initial results from the VISION trial

BACKGROUND

Long-term patency rates for percutaneous peripheral arterial interventions are suboptimal. Optical coherence tomography (OCT) guided atherectomy may yield superior patency by optimizing plaque removal while preserving the tunica media and adventitia.

METHODS

The VISION study is a multicenter prospective study of patients with peripheral arterial disease undergoing OCT guided atherectomy with the Pantheris™ device. In 11 patients enrolled in a single center, we report procedural and clinical outcomes, at 30days and 6months.

RESULTS

The mean age was 63±11years and 73% (n=8) were men. The target lesion was in the superficial femoral artery in 82% (n=9) of the patients. Mean stenosis severity was 87%±10% and mean lesion length was 39±31mm. Procedural success was observed in all patients with no device related complications. Mean post-atherectomy stenosis was 18%±15%. Almost all excised tissue consisted of intimal plaque (94%). At 30days, significant improvements in Rutherford class, VascuQoL scores and ABI were observed, 0.9±0.8 vs. 3.1±0.7 (p=0.01), 4.9±1.9 vs. 3.6±1.5 (p=0.03) and 1.04±0.19 vs. 0.80±0.19 (p<0.01) respectively. At 6months, there were significant improvements in Rutherford class (1.0±1.0 vs. 3.1±0.7, p=0.01) and ABI (0.93±0.19 versus 0.80±0.19, p=0.02) but not in VascuQoL scores (3.7±1.4 versus 3.6±1.5, p=0.48). Target lesion revascularization occurred in 18% (n=2) of the patients.

CONCLUSION

OCT guided atherectomy resulted in high procedural success, no device related complications and encouraging results up to 6months. Histological analysis suggested little injury to the media and adventitia. Larger studies are needed to confirm the efficacy of this approach.