SCAI expert consensus statement for femoral-popliteal arterial intervention appropriate use

2D array imaging system for mechanically-steered, forward-viewing ultrasound guidewire

Approximately 4 million people with peripheral artery disease (PAD) present with critical limb ischemia each year, requiring urgent revascularization to avoid loss of limb. Minimally-invasive (i.e. endovascular) revascularization is preferable due to increased recovery time and increased risk of complications associated with open surgery. However, 40% of people with PAD also have chronic total occlusions (CTOs), resulting in > 20% of revascularization procedures failing when CTOs are present. A steerable robotic guidewire with integrated forward-viewing imaging capabilities would allow the guidewire to navigate through tortuous vasculature and facilitate crossing CTOs in revascularization procedures that currently fail due to inability to route the guidewire. The robotic steering capabilities of the guidewire can be leveraged for 3D synthetic aperture imaging with a simplified, low element count, forward-viewing 2D array on the tip of the mechanically-steered guidewire. Images can then be formed using a hybrid beamforming approach, with focal delays calculated for each element on the tip of the guidewire and for each physical location to which the robotically-steered guidewire is steered. Unlike synthetic aperture imaging with a steerable guidewire having only a single element transducer, an array with even a small number of elements can allow estimation of blood flow and physiological motion in vivo. A miniature, low element count 2D array transducer with 9 total elements (3 × 3) having total dimensions of 1.5 mm × 1.5 mm was designed to operate at 17 MHz. A proof-of-concept 2D array transducer was fabricated and characterized acoustically. The developed array was then used to image a wire target, a peripheral stent, and an ex vivo porcine iliac artery. Images were formed using the described synthetic aperture beamforming strategy. Acoustic characterization showed a mean resonance frequency of 17.6 MHz and a -6 dB bandwidth of 35%. Lateral and axial resolution were 0.271 mm and 0.122 mm, respectively, and an increase in SNR of 4.8 dB was observed for the 2D array relative to the single element case. The first 2D array imaging system utilizing both mechanical and electronic steering for guidewire-based imaging was developed and demonstrated. A 2D array imaging system operating on the tip of the mechanically-steered guidewire provides improved frame rate and increases field of view relative to a single element transducer. Finally, 2D array and single element imaging were compared for introduced motion errors, with the 2D array providing a 46.1% increase in SNR, and 58.5% and 17.3% improvement in lateral and axial resolution, respectively, relative to single element guidewire imaging.

A systematic review of existing appropriate use criteria in cardiovascular disease from the last 15 years

Appropriate use criteria (AUC) aim to impact the provision of high-value care. This scoping review identified AUC regarding the procedural and operative treatment of cardiovascular disease and described the evolution of AUC in this space over time, including changes in the focus, strategy, and language of AUC. The summative presentation of these AUC identifies elements of AUC that may lead to successes in, and barriers to, implementation across disease processes, specialties, and societies. AUC topics include coronary artery disease, peripheral artery disease, valvular disease, venous disease, renal artery stenosis, and mesenteric ischemia, among others.

Endovascular Therapy with Interwoven Nitinol Stent Placement after Predilation for Heavily Calcified Femoropopliteal Artery Disease: Results of the BURDOCK Study

PURPOSE

To investigate the 1-year and 2-year clinical outcomes of interwoven stent (IWS) implantation for symptomatic femoropopliteal arterial disease with calcification.

MATERIAL AND METHODS

This prospective multicenter study evaluated 308 limbs (63% with the peripheral arterial calcium scoring system 3 and 4 severe calcification and 87% with ≥180° calcification on intravascular ultrasound) of 299 patients (diabetes in 66.9%, chronic renal failure in 52.8%, and dialysis in 49.2%) who underwent IWS (Supera; Abbott, Abbott Park, Illinois) implantation after sufficient predilation (residual stenosis < 30%) for calcified femoropopliteal lesions. The primary outcome measure was primary patency (freedom from restenosis) at 1 and 2 years, whereas the secondary outcome measure included freedom from clinically driven target lesion revascularization (CD-TLR). Clinical parameters associated with loss of patency were explored.

RESULTS

Kaplan-Meier analysis showed that primary patency was 88.2% (95% confidence interval [CI], 84.5%-92.1%) at 1 year and 80.8% (95% CI, 76.1%-85.8%) at 2 years. The CD-TLR-free rate was 96.5% and 94.8% at 1 and 2 years, respectively. The characteristics associated with loss of patency were restenotic lesion with and without stent implantation (adjusted hazard ratio, 1.96 and 2.40; P = .047 and .041, respectively), chronic total occlusion (adjusted hazard ratio, 1.88; P = .022), and popliteal involvement (adjusted hazard ratio, 2.60; P = .002).

CONCLUSIONS

The implantation of IWS after sufficient predilation for calcified femoropopliteal atherosclerotic disease demonstrated clinically acceptable primary patency.

Short-term efficacy and safety of TurboHawk atherectomy for in-stent restenosis in peripheral artery disease: a single-centre experience

BACKGROUND

Information regarding the efficacy of the TurboHawk atherectomy for the treatment of in-stent restenosis (ISR) in patients with peripheral artery disease (PAD) of the lower extremity is scarce. This study was performed to investigate the curative efficacy and safety of the TurboHawk system for ISR in PAD patients over 60 years old.

METHODS

The TurboHawk atherectomy device was used to treat ISR in 28 patients with PAD. The intraoperative, 2-day postoperative, 3-month, and 2-year follow-up data were obtained. Differences in the ankle-brachial index (ABI), Rutherford class and minimum diameter of the femoral-popliteal artery were analysed along with the correlations of the factors associated with patency.

RESULTS

Twenty-six patients (92.86%) had successful surgeries. All patients reported alleviation of pain and intermittent claudication after surgery. One patient who had a malignant hepatoma and coronary heart disease received an amputation on the 76th postoperative day and another patient who had atrial fibrillation received a thrombectomy on the 40th postoperative day. TurboHawk atherectomy increased the ABI (from 0.30 to 0.70, P < 0.0001) and minimum diameter (from 0 to 4.93 mm, P < 0.0001) and reduced the Rutherford class (from 4.00 to 2.00, P < 0.0001). During the 3-month follow-up, the median minimum diameter, ABI, and Rutherford class were 4.12, 0.69, and 2.00, respectively. No death happened during the 3-month follow-up.

CONCLUSIONS

The TurboHawk atherectomy is a safe and effective technique for ISR in PAD patients over 60 years old.

The role of directional atherectomy in critical-limb ischemia

Background:

Our aim was to review the current literature of the use of directional atherectomy (DA) in the treatment of lower extremity critical-limb ischemia.

Methods:

A search for relevant literature was performed in PubMed and PubMed Central on 16 April 2020, sorted by best match. Three searches across two databases were performed. Articles were included that contained clinical and procedural data of DA interventions in lower extremity critical-limb ischemia patients. All studies that were systematic reviews were excluded.

Results:

Eleven papers were included in this review. Papers were examined under several parameters: primary patency and secondary patency, limb salvage/amputation, technical/procedural success, complications/periprocedural events, and mean lesion length. Primary and secondary patency rates ranged from 56.3% to 95.0% and 76.4% to 100%, respectively. Limb salvage rates ranged from 69% to 100%. Lesion lengths were highly varied, representing a broad population, ranging from 30 ± 33 mm to 142.4 ± 107.9 mm.

Conclusions:

DA may be a useful tool in the treatment of lower extremity critical-limb ischemia.

Impact of chronic outward force on arterial responses of proximal and distal of long superficial femoral artery stent

BACKGROUND

Self-expanding nitinol stent (SENS) implantation is commonly oversized in the superficial femoral artery (SFA), and leads to chronic outward force (COF) and in-stent restenosis (ISR). This study aimed to investigate the impact of COF of oversizing SENS on ISR of SFA.

METHODS

In patients with implanted SENS in SFA, intimal hyperplasia especially between proximal segment and distal segment was evaluated by quantitative angiography, and the impact of COF on mid-term angiographic outcomes was investigated. In addition, porcine model with implanted SENS was used to evaluate the impact of COF on angiographic and histopathologic outcomes at 1 month. Excised stented arteries were evaluated by histopathologic analysis.

RESULTS

We analyzed 65 SENS in 61 patients with follow-up angiography at 6 months to 1 year. The baseline diameter was 6.8 ± 0.71 mm and length were 97.0 ± 33.8 mm for the SENS. The ratio of the diameter of the stent to the reference vessel was 1.3 ± 0.24 at the proximal portion and 1.53 ± 0.27 at the distal portion (P < 0.001). In the long SFA stent, stent-to-vessel ratio was significantly higher in the distal stent than in the proximal stent (1.3 ± 0.2 vs. 1.55 ± 0.25, P = 0.001). ISR incidence was higher at the distal stent (37.3% vs 52.6%, P = 0.029). All 11 pigs survived for 4 weeks after SENS implantation. The vessel diameter was 4.04 ± 0.40 mm (control group) vs 4.45 ± 0.63 mm (oversized group), and the implanted stent diameter was 5.27 ± 0.46 mm vs. 7.18 ± 0.4 mm (P = 0.001). The stent-to-vessel diameter ratio was 1.31 ± 0.12 versus 1.63 ± 0.20 (P < 0.001). After 4 weeks, restenosis % was 29.5 ± 12.9% versus 46.8 ± 21.5% (P = 0.016). The neointimal area was 5.37 ± 1.15 mm² vs. 8.53 ± 5.18 mm² (P = 0.05). The restenosis % was 39.34 ± 8.53% versus 63.97 ± 17.1% (P = 0.001).

CONCLUSIONS

COF is an important cause of restenosis in the distal portion of the SFA stent. Optimal sizing of the SFA stent is important to reduce the incidence of restenosis. Therefore, COF was an important factor of restenosis following distal SFA stenting.

Better treatment option in chronic superficial femoral artery occlusive disease: comparison of methods (meta-analysis)

Introduction: The objective is to evaluate the frequency of primary obstruction events (PrO) during one-year follow-up after performing excisional atherectomy with the SilverHawk/TurboHawk atherectomy device (S/TH) or remote superficial femoral artery endarterectomy (RSFAE) in patients with the chronic superficial femoral artery occlusive disease (СSFAOD).

Methods: We included all randomized clinical trials (RCTs) and not-RCTs concerning the treatment of patients with СSFAOD after S/TH and RSFAE without duration.

Results: Twenty-nine items (1990-2017) were discovered; 27 articles on the levels of evidence were included in qualitative synthesis; 9 studies (meta-analysis) were included in quantitative synthesis. The results of 2762 patients’ treatment were summed up in our analysis (1422 patients S/TH; 1340 patients RSFAE). All included reports were at low risk of bias. According to the criterion "frequency of PrO" during one-year follow-up, the pooled Hazard Ratios indicate significant favours of S/TH if compared it with RSFAE (HR= 0.66 (0.57 to 0.76, P < 0.00001), I2 = 9%).

Conclusion: Our study showed that S/TH with the SpiderFX device (distal embolic protection) are safe and effective treatment option for short lesion (<15 cm) in patients with СSFAOD. The usage of S/TH methods significantly reduced number of PrO if compared it with RSFAE. In long-segment lesion (>15 cm) in patients with СSFAOD, RSFAE may be considered better than an endovascular procedure. But still it is necessary to conduct well-planned randomized studies to determine effectiveness and safety of the compared methods (S/TH and RSFAE) in patients with long-segment lesion (>15 cm).

High Reintervention and Amputation Rates After Outpatient Atherectomy for Claudication

Outpatient use of atherectomy for peripheral arterial disease has grown rapidly and outcomes are poorly understood. We analyzed outcomes of atherectomy done for claudication, comparing office and hospital outpatient settings. Analysis of Medicare Part B claims data was performed for incident femoral–popliteal or tibial–peroneal atherectomy from 2012 to 2014. Longitudinal analysis assessed services 18 months before, during, and up to 18 months after the incident peripheral vascular intervention (PVI). Differences between office-based and hospital outpatient-based settings were assessed using χ2 and Fisher exact tests. Comparing procedure settings, significant differences in race (femoral–popliteal: P = .04, tibial–peroneal: P = .001), chronic renal failure (femoral–popliteal: P = .002), and hypertension (femoral–popliteal: P = .01, tibial–peroneal: P = .006) were found. Nine hundred twenty-four patients undergoing femoral–popliteal atherectomy were analyzed (262 office based, 662 hospital outpatient based); 42.7% of office-based and 36.9% of hospital outpatient-based femoral–popliteal atherectomy patients had repeat PVI within 18 months ( P = .10). Major amputation was performed in 2.3% and 3.2% of patients in office and hospital outpatient settings, respectively ( P = .47). Four hundred twenty-three patients undergoing tibial–peroneal atherectomy were analyzed (202 office based, 221 hospital outpatient based); 46.5% of office-based and 38.9% of hospital outpatient-based tibial–peroneal atherectomy patients had repeat PVI within 1 year ( P = .11). Major amputation was performed in 5.0% and 8.1% of patients in office and hospital outpatient settings, respectively ( P = .19). Our study demonstrates higher than expected rates of major amputation for patients undergoing peripheral arterial atherectomy with regard to previously reported rates. Further studies may be required to prove the efficacy and safety of atherectomy for occlusive disease in the femoral–popliteal and tibial–peroneal segments to ensure outcomes are not worse than the natural history of medically managed claudicants.

Management of Critical Limb Ischemia

Critical limb ischemia (CLI) is a clinical syndrome of ischemic pain at rest or tissue loss, such as nonhealing ulcers or gangrene, related to peripheral artery disease. CLI has a high short-term risk of limb loss and cardiovascular events. Noninvasive or invasive angiography help determine the feasibility and approach to arterial revascularization. An endovascular-first approach is often advocated based on a lower procedural risk; however, specific patterns of disease may be best treated by open surgical revascularization. Balloon angioplasty and stenting form the backbone of endovascular techniques, with drug-eluting stents and drug-coated balloons offering low rates of repeat revascularization. Combined antegrade and retrograde approaches can increase success in long total occlusions. Below the knee, angiosome-directed angioplasty may lead to greater wound healing, but failing this, any straight-line flow into the foot is pursued. Hybrid surgical techniques such as iliac stenting and common femoral endarterectomy are commonly used to reduce operative risk. Lower extremity bypass grafting is most successful with a good quality, long, single-segment autogenous vein of at least 3.5-mm diameter. Minor amputations are often required for tissue loss as a part of the treatment strategy. Major amputations (at or above the ankle) limit functional independence, and their prevention is a key goal of CLI therapy. Medical therapy after revascularization targets risk factors for atherosclerosis and assesses wound healing and new or recurrent flow-limiting disease. The ongoing National Institutes of Health-sponsored Best Endovascular Versus Best Surgical Therapy in Patients With Critical Limb Ischemia (BEST-CLI) study is a randomized trial of the contemporary endovascular versus open surgical techniques in patients with CLI.

Clinical impact and risk stratification of balloon angioplasty for femoropopliteal disease in nitinol stenting era: Retrospective multicenter study using propensity score matching analysis

Objective:

Nitinol stenting could bring the better outcome in endovascular therapy for femoropopliteal disease. However, it might be expected that recent marked advances in both device technology and operator technique had led to improved efficacy of balloon angioplasty even in this segment. The aims of this study were to evaluate the clinical impact of balloon angioplasty for femoropopliteal disease and make risk stratification clear by propensity score matching analysis.

Methods:

Based on the multicenter retrospective data, 2758 patients (balloon angioplasty: 729 patients and nitinol stenting: 2029 patients), those who underwent endovascular therapy for femoropopliteal disease, were analyzed.

Results:

The propensity score matching procedure extracted a total of 572 cases per group, and the primary patency rate of balloon angioplasty and nitinol stenting groups after matching was significantly the same (77.2% vs 82.7% at 1 year; 62.2% vs 64.3% at 3 years; 47.8% vs 54.3% at 5 years). In multivariate Cox hazard regression analysis, significant predictors for primary patency were diabetes mellitus, regular dialysis, cilostazol use, chronic total occlusion, and intra-vascular ultra-sonography use. The strategy of balloon angioplasty was not evaluated as a significant predictor for the primary patency. After risk stratification using five items (diabetes mellitus, regular dialysis, no use of intra-vascular ultra-sonography, chronic total occlusion, and no use of cilostazol: the DDICC score), the estimated primary patency rates of each group (low, DDICC score 0–2; moderate, DDICC score 3; high risk, DDICC score 4–5) were 88.6%, 78.3%, and 63.5% at 1 year; 75.2%, 60.7%, and 39.8% at 3 years; and 66.0%, 47.1%, and 26.3% at 5 years (p < 0.0001). The primary patency rate of balloon angioplasty and nitinol stenting groups was significantly the same in each risk stratification.

Conclusion:

This study suggests that balloon angioplasty does not have inferiority to nitinol stenting but does have favorable efficacy in femoropopliteal segment by careful risk stratification with the recent advance of technique.

Endovascular intervention for peripheral artery disease

Advances in endovascular therapies during the past decade have broadened the options for treating peripheral vascular disease percutaneously. Endovascular treatment offers a lower risk alternative to open surgery in many patients with multiple comorbidities. Noninvasive physiological tests and arterial imaging precede an endovascular intervention and help localize the disease and plan the procedure. The timing and need for revascularization are broadly related to the 3 main clinical presentations of claudication, critical limb ischemia, and acute limb ischemia. Many patients with claudication can be treated by exercise and medical therapy. Endovascular procedures are considered when these fail to improve quality of life and function. In contrast, critical limb ischemia and acute limb ischemia threaten the limb and require more urgent revascularization. In general, endovascular treatments have greater long-term durability for aortoiliac disease than femoral popliteal disease. Infrapopliteal revascularization is generally reserved for critical and acute limb ischemia. Balloon angioplasty and stenting are the mainstays of endovascular therapy. New well-tested innovations include drug-eluting stents and drug-coated balloons. Adjunctive devices for crossing chronic total occlusions or debulking plaque with atherectomy are less rigorously studied and have niche roles. Patients receiving endovascular procedures need a structured surveillance plan for follow-up care. This includes intensive treatment of cardiovascular risk factors to prevent myocardial infarction and stroke, which are the main causes of death. Limb surveillance aims to identify restenosis and new disease beyond the intervened segments, both of which may jeopardize patency and lead to recurrent symptoms, functional impairment, or a threatened limb.

Controlled antegrade and retrograde subintimal tracking technique for endovascular treatment of the superficial femoral artery with chronic total occlusion

Although providing endovascular treatment for chronic total occlusion (CTO) in patients with peripheral arterial disease is challenging, subintimal angioplasty (SIA) has proven to be an effective procedure. However, the SIA device may not cross CTO lesions because of the inability to achieve re-entry into the distal true lumen in some cases. We herein describe 2 cases of CTO of the superficial femoral artery (SFA) segment in which we failed to cross the site of CTO using the SIA technique and therefore employed the controlled antegrade and retrograde subintimal tracking (CART) technique to successfully treat the CTO lesions of SFA. When using the CART technique, there is no need to perform extension of the region of subintimal dissection beyond the occluded lesion, which may be useful for managing CTO lesions.