High-grade, non-flow-limiting dissections do not negatively impact long-term outcome after paclitaxel-coated balloon angioplasty: an additional analysis from the THUNDER study

Treating post-angioplasty dissection in the femoropopliteal arteries using the tack endovascular system: Tack optimized balloon angioplasty II 24-month results

OBJECTIVES

The TOBA (Tack Optimized Balloon Angioplasty) II trial is a prospective, single-arm, multicenter study that investigated Tack treatment for patients with dissection after angioplasty in the superficial femoral artery and/or proximal popliteal artery. The Tack device is a nitinol-based, short (6 mm), stent-like implant with low outward force that can be deployed in a targeted fashion to treat vascular dissection. TOBA II primary results through 12 months have been published previously. This report provides follow-up safety and efficacy results through 24 months (RC).

METHODS

The TOBA II trial enrolled 213 patients with Rutherford classification 2 to 4 and a de novo or non-stented restenotic lesion in the superficial femoral artery and/or proximal popliteal artery who developed a dissection of any grade after treatment with plain balloon or drug-coated balloon (DCB) angioplasty. Participants were followed for 30 days, 6 months, 12 months, 24 months, and 36 months following the procedure. Evaluations included clinically driven target lesion revascularization (CD-TLR), ankle-brachial index, Rutherford classification, peripheral artery questionnaire, quality of life assessed by the EQ-5D-3L, and the Walking Impairment Questionnaire.

RESULTS

At enrollment, mean age was 68.2 ± 9.1 years, 70.9% were male, and 95.8% of patients were categorized as RC 2 or 3. The distribution of balloon types in the study were standard balloons: 42.3%; and drug-coated balloons: 57.7%. At 24-month follow-up, 167 patients (78.4%) had available data. The overall survival rate at 24 months was 95.4% and there were no major amputations during this time. After 24 months of follow-up, the Kaplan-Meier freedom from CD-TLR was 77.7%. Rutherford classification, ankle-brachial index, and quality of life were significantly improved compared with baseline through 24 months.

CONCLUSIONS

The TOBA II 24-month data demonstrate durable intermediate-term outcomes with the use of the Tack Endovascular System. Tack deployment was a safe and effective therapeutic option for dissection repair following angioplasty.

Research progress of drug eluting balloon in arterial circulatory system

The arterial circulatory system diseases are common in clinical practice, and their treatment options have been of great interest due to their high morbidity and mortality. Drug-eluting balloons, as a new type of endovascular interventional treatment option, can avoid the long-term implantation of metal stents and is a new type of angioplasty without stents, so drug-eluting balloons have better therapeutic effects in some arterial circulatory diseases and have been initially used in clinical practice. In this review, we first describe the development, process, and mechanism of drug-eluting balloons. Then we summarize the current studies on the application of drug-eluting balloons in coronary artery lesions, in-stent restenosis, and peripheral vascular disease. As well as the technical difficulties and complications in the application of drug-eluting balloons and possible management options, in order to provide ideas and help for future in-depth studies and provide new strategies for the treatment of more arterial system diseases.

The fate of coronary dissections left after sirolimus-coated balloon angioplasty: A prespecified subanalysis of the EASTBOURNE study

OBJECTIVES

We sought to understand the clinical outcomes of dissections left untreated after sirolimus drug-coated balloon (DCB) angioplasty.

BACKGROUND

DCB may be a valuable alternative to stents for the treatment of native coronary lesions, but the risk of having a dissection after DCB-angioplasty is not negligible. While type A and B dissections can be safely treated conservatively, some debate exists regarding type C dissections. We previously showed the safety of dissections left untreated after second-generation paclitaxel-DCB. However, the fate of dissections after sirolimus-DCB angioplasty has not been investigated so far.

METHODS

EASTBOURNE is a prospective, multicenter, international, investigator-driven study aiming to explore the safety and efficacy of a novel sirolimus-DCB. This study enrolled a consecutive, all-comer population of coronary artery disease patients and is the largest prospective study on DCB so far. Primary endpoints of the study, target-lesion revascularization (TLR), and other clinical endpoints at 12 months, have been presented elsewhere. This is a prespecified subgroup analysis of the patients left with not-flow limiting dissection after DCB angioplasty, with complete 12 months follow-up and comparison between patients left with a dissection versus patients with DCB used for de novo lesions.

RESULTS

Between September 2016 and November 2020, a total of 2123 patients were enrolled at 38 study centers. Seventy-three patients were left with nonflow limiting dissections (43 type A, 27 type B, 3 type C) and underwent complete 1-year clinical follow-up. In the nondissection group, 1110 patients had de-novo coronary artery disease while 900 had in-stent restenosis. Baseline characteristics were similar between the groups, while the dissection group was associated with longer lesions (23.8 vs. 18.4 mm, p < 0.001) and more frequent use of predilation (100 vs. 91.4%, p = 0.016). At 12-month follow-up, no significant differences among the groups were found, with a total of 1.25% TLR in the dissection cohort versus 5.6% in the de-novo cohort (p = 0.13), and an overall rate of major adverse cardiovascular events of 4.4% versus 10.1% (p = 0.18). Total death (1.5 vs. 2.6, p = 0.87), cardiac death, myocardial infarction (0% vs. 2.5%, p = 0.35), and bleedings did not differ significantly among the groups as well.

CONCLUSIONS

In this subgroup analysis of the EASTBOURNE study of consecutive patients treated with new-generation sirolimus DCB, dissections left untreated after angioplasty did not lead to an increase in adverse events.

Optimized drug-coated balloon angioplasty of the superficial femoral and proximal popliteal arteries using the Tack Endovascular System: Tack Optimized Balloon Angioplasty (TOBA) III 24-month results in standard and long lesions

OBJECTIVE

The Tack Endovascular System is a minimal-metal dissection repair device that is purpose-built to treat post-percutaneous angioplasty (PTA) arterial dissections in patients with peripheral arterial disease (PAD). The Tack Optimized Balloon Angioplasty (TOBA) III trial evaluated the safety and effectiveness of the Tack Endovascular System in patients with superficial femoral artery (SFA) and/or proximal popliteal artery (PPA) dissection after PTA with a drug-coated balloon (DCB). The objective of this study is to report the results in the standard- (SL) and long-lesion (LL) cohorts through 24 months.

DESIGN

The TOBA III study was a prospective, multicenter, single-arm study including patients suffering from Rutherford category 2-4 PAD. Outcomes were assessed according to pre-specified lesion length in SL ( ≥ 20 mm and ≤150 mm) and LL ( > 150 mm and ≤250 mm) cohorts. Follow-up was through 24 months.

RESULTS

TOBA III enrolled 201 patients, 169 patients in the SL cohort and 32 in the LL cohort. At 24 months, the Kaplan-Meier estimates of freedom from major adverse events were 91.7% and 82.6% for the SL cohort and LL cohort, respectively. Kaplan-Meier estimates of freedom from clinically driven-target lesion revascularization (CD-TLR) were 92.3% in the SL cohort and 82.6% in the LL cohort. At 24 months, 78.8% of SL patients and 69.2% of LL patients experienced an improvement of >2 Rutherford categories (both cohorts p < 0.001). The baseline ankle-brachial index improved from 0.68 ± 0.18 to 0.93 ± 0.16 in the SL (p < 0.001) and from 0.62 ± 0.23 to 0.87 ± 0.15 in the LL cohort (p < 0.001) at 24 months.

CONCLUSION

The 24-month results of the TOBA III trial support the safety and effectiveness of the Tack Endovascular System in patients who required post-PTA dissection repair in the SFA and PPA following DCB angioplasty for claudication and rest pain. In both the SL and LL cohorts, Tack placement was associated with sustained freedom from CD-TLR through 24 months as well as sustained improvements in Rutherford categories, ankle-brachial index, and quality of life.

Treatment of Peripheral Artery Disease Using Injectable Biomaterials and Drug-Coated Balloons: Safety and Efficacy Perspective

The possibility of injectable biomaterials being used in the therapy of peripheral artery disease (PAD) is investigated in this article. We conducted a thorough review of the literature on the use and efficacy of biomaterials (BMs) and drug-coated balloons (DCBs). These BMs included hydrogels, collagen scaffolds, and nanoparticles. These BMs could be used alone or in combination with growth factors, stem cells, or gene therapy. The treatment of peripheral artery disease with DCBs is increasingly common in the field of interventional angiology. Studies have been carried out to examine the effectiveness of paclitaxel-coated balloons such as PaccocathTM in lowering the frequency with which further revascularization operations are required. PCB angioplasty and angioplasty without paclitaxel did not significantly vary in terms of mortality, according to the findings of a recent meta-analysis that included the results of four randomized controlled studies. On the other hand, age was found to be a factor that predicted mortality. There was a correlation between the routine utilization of scoring balloon angioplasty along with DCBs and improved clinical outcomes in de novo lesions. In both preclinical and clinical testing, the SelutionTM DCB has demonstrated efficacy and safety, but further research is required to determine whether or not it is effective and safe over the long term. In addition, we reviewed the difficulties involved in bringing injectable BMs-based medicines to clinical trials, including the approval processes required by regulatory bodies. Injectable BMs have a significant amount of therapeutic promise for PAD, which highlights the need for more research and clinical studies to be conducted in this field. In conclusion, this research focuses on the potential of injectable BMs and DCBs in the treatment of PAD as well as the hurdles that must be overcome in order to translate these treatments into clinical trials. In this particular field, there is a demand for further research as well as clinical trials.

Drug-Coated Balloon versus Drug-Eluting Stent: The Debate of Leave Nothing Behind

Endovascular techniques for peripheral artery disease have changed significantly in the past 10 years with advances in technology and data. Treatment of superficial femoral disease is complex secondary to the length, degree of calcification, high rate of chronic total occlusion, and areas of flexion within this vessel. Use of drug-coated devices has increased the interventionalist's toolbox with the objective to improve freedom from target lesion revascularization and primary patency. There remains debate as to which devices may reach these goals while also limiting overall morbidity and mortality. This article aims to highlight recent advances in the literature regarding the use of drug-coated devices.

Two-year clinical outcomes and predictors of restenosis following the use of polymer-coated paclitaxel-eluting stents or drug-coated balloons in patients with femoropopliteal artery disease

We aimed to assess the clinical performance and risk factors for patency loss within 2 years following the use of polymer-coated paclitaxel-eluting stents (PC-PESs) and drug-coated balloons (DCBs) in patients with lower extremity artery disease. Multi-center registry data from 151 patients (65 and 86 treated with PC-PES and DCB, respectively) were retrospectively investigated. Two-year primary patency (PP) and clinically driven target lesion revascularization (CD-TLR) were evaluated using Kaplan-Meier analysis. Predictors of restenosis within 2 years of the procedures were analyzed using the random survival forest method. The consistent predictors of restenosis within 1 and 2 years were assessed and validated using Kaplan-Meier analysis. Two-year PP was 77.2 and 57.2% (log rank p = 0.047) and freedom from CD-TLR was 84.4 and 84.8% in the PC-PES and DCB groups, respectively (log rank p = 0.89). In the DCB group, most of the patients (n = 77, 89.5%) were treated with high-dose DCB. Consistent predictors of restenosis were lower vessel diameter and severity of Clinical Frailty Scale in the PC-PES group, and severity of peripheral artery calcification scoring system grade, severity of post dissection pattern, and smaller vessel diameter in the DCB group. The validation analysis revealed that patients with consistent predictors had significantly worse PP values than that of those without in the PC-PES (87.9% vs. 55.3%, log rank p = 0.003) and DCB groups (75.9% vs. 35.2%, log rank p = 0.001). The 2-year PP of DCBs was lower than that of PC-PESs. A smaller vessel diameter could predict restenosis in both devices. Vessel calcification and dissection should be considered when using DCB to ensure longer term patency.

Specialty Balloons for Vessel Preparation During Infrainguinal Endovascular Revascularization Procedures: A Review of Literature

Balloon angioplasty with/without utilizing drug eluting technology or stenting constitutes the treatment of choice for a significant percentage of patients with peripheral artery disease requiring an intervention. However, in cases of diffuse disease and plaque complexity, angioplasty may lead to dissection, recoil, and/or early restenosis, making vessel preparation a key component for successful and durable endovascular revascularization outcome. This review of literature aims to present contemporary data for several commercially available specialty balloons that have been designed to minimize the arterial wall stress of conventional balloon angioplasty and facilitate technical success, as well as long-term patency.

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.

Outcomes of Stented vs Nonstented Femoropopliteal Lesions Treated With Drug-Coated Balloon Angioplasty

PURPOSE

Drug-coated balloon (DCB) angioplasty has been increasingly used for the treatment of lower limb peripheral artery disease (PAD). However, bail-out stenting may be necessary in cases of suboptimal angioplasty. This study investigated the outcomes of femoropopliteal disease treated with DCB with/without bail-out stenting.

MATERIALS AND METHODS

This was a single-center retrospective study enrolling 166 consecutive patients (DCB+stent: n=81 vs DCB: n=85) with 253 femoropopliteal lesions (DCB+stent: n=99 vs DCB: n=154) treated with DCB with/without stenting. Bail-out stenting was performed at the operator discretion for postangioplasty dissections or otherwise suboptimal angiographic result (>30% residual stenosis). Cox regression analysis was performed to examine the outcomes of DCB with/without stenting during 2-year follow-up.

RESULTS

The baseline clinical characteristics were similar between the 2 groups. About half of the patients presented with critical limb ischemia, with most of the lesions located at the superficial femoral artery. The overall mean lesion length was 147±67 mm. The most frequent bail-out stent types were bare metal stents (BMS) (53.5%) followed by drug-eluting stents (DES) (41.4%). Lesions requiring bail-out stenting were on average longer (177±67 mm vs 127±59 mm; p<0.01) and on average had higher prevalence of flow-limiting postangioplasty dissections. The overall procedural success rate was 94% without any differences between the 2 groups. Both the stented and nonstented treatment modalities were effective and safe, demonstrating similar rates of 2-year freedom from major adverse limb event (stented: 71.3% vs nonstented: 64.4%) and 2-year freedom from target lesion revascularization (stented: 77.1% vs nonstented: 72.3%) during following up. The use of DES as bail-out therapy was associated with a lower risk of 2-year death compared with the use of BMS (DES: 97.2% vs BMS: 75.8%; p=0.01).

CONCLUSION

Drug-coated balloon with bail-out stenting is a viable treatment option for cases of suboptimal DCB results, promising similar efficacy with DCB-alone procedures. However, as the patency of stents at the femoropopliteal segment may be a challenge due to the biomechanical stress of the artery, the efficacy of DCB+bail-out stenting should be further evaluated. In addition, future studies are needed to determine which grades of post-DCB dissections should be treated and optimize current bail-out strategies.

Arterial Preparation by Longitudinal Micro-Incisions Before Balloon Angioplasty of the Superficial Femoral and Popliteal Artery: Acute and 12-Month Results

PURPOSE

Percutaneous transluminal angioplasty (PTA) with conventional plain old balloon (POBA) and/or drug-coated balloon (DCB) is the primary intervention to treat peripheral artery stenoses. However, acute dissections during the procedure and potential for future target lesion revascularization remain procedural complications. The purpose of this study was to assess the acute and 12-month outcomes in patients who underwent novel vessel preparation with longitudinal, controlled-depth micro-incisions prior to PTA.

MATERIALS AND METHODS

Patients with symptomatic lower extremity peripheral arterial disease with a Rutherford class of 2 to 6 and >70% de novo stenosis of the superficial femoral or popliteal arteries were included in this retrospective study. Patients with thrombotic or embolic lesions, restenosis, or in-stent restenosis were excluded. The FLEX Vessel Prep System (FLEX VP) was used to prepare the vessel prior to PTA by creating micro-incisions at the target lesion. The FLEX VP was followed by POBA or paclitaxel DCB.

RESULTS

The study included 65 patients. Lesion characteristics were 90% median stenosis (range = 70%-100%), 75.4% mild-to-severe calcifications, and 33.8% occlusion rate, and median lesion length was 196 (range = 10-480) mm. Following vessel preparation, 82.1% of the patients had low severity dissection or no flow-limiting dissection. The provisional stent rate postprocedure was 16.9%, with a median stent length of 60 mm. The freedom from target lesion revascularization (FFTLR) in 63 evaluable patients at 6 and 12 months was 98.4% and 93.7%, respectively. Freedom from amputation was 100%.

CONCLUSION

In this real-world/all-comers patient population with long, stenotic lesions across the calcification spectrum, vessel preparation with longitudinal micro-incisions prior to PTA was associated with low dissection rate, low dissection severity, low stent implantation, and high FFTLR with the absence of amputation at 12 months relative to published reports in long-lesion cohorts. These results support vessel preparation via micro-incisions.

Comparison of Angiographic Dissection Classification Systems in the Femoropopliteal Arteries Using IVUS Validation and Reliability Testing

PURPOSE

Objective assessment of dissection severity is difficult. Recognition of this has led to the creation of classification systems. This study investigated the performance of the National Heart Lung and Blood Institute (NHLBI) and Kobayashi systems at differentiating severity of femoropopliteal dissection using intravascular ultrasound (IVUS) as the reference standard. Comparison between the 2 systems and the inter- and intra-observer reliability were also investigated.

MATERIALS AND METHODS

Angiographic and IVUS imaging was assessed in 51 cases sourced from a RCT investigating the use of IVUS in femoropopliteal disease. A total of 2 readers independently scored the angiography images according to NHLBI and Kobayashi dissection classification systems and a consensus score was obtained for each system in each case. The NHLBI classification was condensed into 3 grades of dissection to allow comparison between systems. Dissection length, dissection arc, minimum lumen area, and lumen area stenosis were obtained from the IVUS imaging. IVUS parameters were compared between grades of severity for both systems. Agreement in grading between the systems was assessed and IVUS parameters for each level of dissection severity were compared between systems. Inter and intra-observer agreement tested for each system.

RESULTS

Dissection was present on IVUS in 92.2% (47/51) of cases and angiography identified 78.7% (37/47) of these. No difference was present in any IVUS parameters between mild and severe dissections with either classification system. No difference in IVUS findings was present for the same grades of dissection between systems. The 2 systems agreed on severity grade in 47 of 51 cases. The inter-observer agreement was for NHLBI was k=0.549 and k=0.627 for Kobayashi. Intra-observer agreement for NHLBI was k=0.633 and k=0.633 and for Kobayashi was k=0.657 and k=0.297.

CONCLUSION

The lack of difference in IVUS parameters between mild and severe dissection for the NHLBI and Kobayashi systems raises doubts about their ability to effectively differentiate dissection severity. Weak to moderate reliability suggests that variability in interpreting dissection may be higher than acceptable. IVUS imaging is more sensitive for detecting dissection than angiography and research is required to establish the value of adding IVUS to dissection classification systems.

Clinical outcomes and predictors of restenosis in patients with femoropopliteal artery disease treated using polymer-coated paclitaxel-eluting stents or drug-coated balloons

Both polymer-coated paclitaxel-eluting stents (PC-PESs) and drug-coated balloons (DCBs) are used in conjunction with endovascular therapy (EVT) for the treatment of peripheral artery disease (PAD). We aimed to identify the risk factors for the loss of patency following the use of PC-PES and DCB in a real clinical setting. We assessed the multi-center registry data of 151 lesions from 151 patients who underwent EVT for symptomatic PAD in the superficial femoral and proximal popliteal arteries using PC-PES or DCB. One-year primary patency (PP) and clinically driven target lesion revascularization (CD-TLR) were evaluated using Kaplan-Meier analysis. The predictive risk factors for 1-year outcomes were analyzed using the random survival forest method. PC-PES and DCB were used in 65 (43.0%) and 86 (57.0%) cases, respectively. There were no significant differences in 1-year PP or freedom from CD-TLR between PC-PES and DCB. PP occurred in 85.4% and 80.2% of cases in the PC-PES and DCB groups, respectively (log-rank p = 0.65), while freedom from CD-TLR was noted in 92.7% and 94.1% of cases in the PC-PES and DCB groups, respectively (log-rank p = 0.73). In order of importance, a Clinical Frailty Scale score ≥ 6, female sex, lower proximal vessel diameter, lower body mass index, and younger and older age were identified as predictive risk factors of restenosis in the PC-PES group. Peripheral artery calcification scoring system grade of ≥ 2, post-dissection pattern ≥ D, lower proximal and distal vessel diameter, and lesion length ≥ 100 mm were identified as predictive risk factors of restenosis, in order of importance, in the DCB group. Both PC-PES and DCB were associated with favorable clinical outcomes within 1 year in patients with femoropopliteal artery disease. Furthermore, several factors that could predict restenosis within 1 year following the use of each device were detected.

Outcomes of Dissection Angles as Predictor of Restenosis after Drug-Coated Balloon Treatment

AIM

The predictors of restenosis after endovascular therapy (EVT) with paclitaxel drug-coated balloons (DCBs) have not been clearly established. The present study aimed to investigate the association of post-procedural dissection, as evaluated using intravascular ultrasound (IVUS), with the risk of restenosis following femoropopliteal EVT with paclitaxel DCBs.

METHODS

In the present single-center retrospective study, 60 de novo femoropopliteal lesions (44 patients) that underwent EVT with DCBs, without bail-out stenting, were enrolled. The primary outcome was 1-year primary patency. Risk factors for restenosis were evaluated using a Cox proportional hazards regression model and random survival forest analysis.

RESULTS

The 1-year primary patency rate was 57.2% [95% confidence interval, 45%-72%]. IVUS-evaluated post-procedural dissection was significantly associated with the risk of restenosis (P=0.002), with the best cutoff point of 64º [range, 39º-83º]. The random survival forest analysis showed that the variable importance measure of IVUS-evaluated dissection was significantly lower than that of the reference vessel diameter (P＜0.001), not different from that of the lesion length (P=0.41), and significantly higher than that of any other clinical feature (all P＜0.05).

CONCLUSION

IVUS-evaluated post-procedural dissection was associated with 1-year restenosis following femoropopliteal EVT with DCB.

Five-Year Outcomes of Post-Drug-Coated Balloon Angioplasty Dissection in Complex Femoropopliteal Artery Disease

Objective

To evaluate the long-term outcomes after drug-coated balloon (DCB) angioplasty dissection in patients with complex femoropopliteal artery disease.

Methods

Two hundred patients with femoropopliteal peripheral artery disease were enrolled in the AcoArt I trial and randomly assigned to either the DCB or percutaneous transluminal angioplasty (PTA) group. A total of 86 patients with post-balloon angioplasty dissection were reanalyzed. The primary endpoint was clinically driven target lesion revascularization (CD-TLR) over five years. Kaplan–Meier curve estimates were used to evaluate the association between the treatment and CD-TLR. Interaction and stratified analyses were also performed.

Results

Over five years, patients treated with DCB angioplasty demonstrated an acceptable effect with a numerically higher but not statistically significant rate of freedom from CD-TLR compared with those treated by PTA (Kaplan–Meier estimate of 77.6% vs 64.4%; log-rank P = 0.08). Among the patients who underwent TLR, the mean time from intervention to TLR in the DCB group was significantly prolonged compared to the PTA group (P < 0.001). The stratified analysis showed that the Rutherford classification played an interactive role in the association between the DCB angioplasty and low CD-TLR rate at five years. No significant difference in the all-cause mortality was found in the patients with post-balloon angioplasty dissection between the two treatment groups.

Conclusion

The five-year follow-up outcomes of the post-balloon angioplasty dissection in the AcoArt I trial demonstrated that DCB angioplasty is more trustworthy than PTA, with a higher rate of freedom than CD-TLR and sustained improvement in clinical symptoms. However, the all-cause mortality rate in patients with femoropopliteal lesions is similar after both DCB angioplasty and PTA.

Clinical Trial Registration

http://www.clinicaltrials.gov.

Unique Identifier

NCT01850056.

Device profile of the tack endovascular system® for the treatment of peripheral arterial disease: overview of safety and efficacy

Introduction: The 6 F Tack Endovascular System® is approved by the United States Food and Drug Administration (FDA) for post-percutaneous transluminal angioplasty (PTA) dissection repair in the superficial femoral and proximal popliteal arteries, and the 4 F System for post-PTA dissection repair in the mid/distal popliteal, peroneal and tibial arteries. The latter is the first FDA approval for an infra-popliteal implantable device.Areas covered: An evaluation of the Tack Endovascular System® design and a summary of the current safety and efficacy data.Expert opinion: Endovascular intervention for the treatment of symptomatic peripheral arterial disease (PAD) in the lower extremities is complicated by long-lesion length, extensive calcification and, below the knee, narrow vessel diameter. PTA is a foundational element for the treatment of these lesions and works by causing a controlled dissection and vessel expansion of the target lesion. Occasionally, dissections can extend beyond the target lesion and/or become hemodynamically significant due to lumen impingement necessitating additional intervention. Historically these dissections were treated with the use of stents, prolonged balloon inflation time or went untreated. The Tack Endovascular System® was designed to provide operators a safe and effective device which could repair post-PTA dissections while preserving future treatment options.

Association of Postangioplasty Femoropopliteal Dissections With Outcomes After Drug-Coated Balloon Angioplasty in the Femoropopliteal Arteries

PURPOSE

Balloon angioplasty for the treatment of femoropopliteal lesions is often complicated by postangioplasty dissections. While dissections are known to affect patency and reintervention after balloon angioplasty, the association between dissections and major adverse limb event (MALE) after drug-coated balloon (DCB) angioplasty remains uncertain. Thus, the postangioplasty dissection and bailout stenting patterns were investigated.

MATERIALS AND METHODS

This was a single-center retrospective study enrolling patients with de novo femoropopliteal lesions treated with DCB with/without stenting. Postangioplasty target vessel dissection was graded based to the coronary artery classification grades A-F, with grade C-F considered "severe." Cox regression analysis was performed to examine the association of dissection severity with outcomes during 2-year follow up, among nonstented cases.

RESULTS

In 85.3% of the cases (N=203/238) a postangioplasty dissection was observed. The average dissection length was 55.57 mm (SD 36.71 mm), with 1 dissection present in 91.8% (N=180/196) and 2 or more dissections present in 8.2% (N=16/196). Dissection severity was grade A (19.8%), B (20.6%), C (23.1%), D (10.9%), E (10.1%), and F (0.8%). Bailout stenting was required in 40.4% of the patients, being more prevalent among grade C and grade E cases. Among 142 nonstented cases, dissections were present in 85.2%. A total of 75 (52.8%) of these dissections were grade A and B, while 46 (32.4%) were grade C to F. Among nonstented cases, grade C (hazard ratio [HR] 5.83; 95% CI 1.25 to 27.31; p=0.025) and grade D (HR 6.32; 95% CI 1.39 to 28.86; p=0.017) vs grade A dissections were associated with a higher risk for 2-year MALE. Multivariate analysis adjusting for several lesion characteristics demonstrated a statistically significant higher risk for 2-year MALE among the severe dissection group (HR 2.94; 95% CI 1.27 to 6.79; p = 0.012). Interestingly, the risks of limb loss (HR 1.30; 95% CI 0.22 to 7.79; p=0.774) and repeat revascularization (HR 0.95; 95% CI 0.40 to 2.26; p=0.905) during follow-up were similar between the 2 groups.

CONCLUSION

This study indicated that nonstented moderate and severe postangioplasty dissections after DCB angioplasty were associated with higher risk for MALE. Future studies are needed to validate our results and determine other dissection characteristics (eg, total dissection length, lumen area, total number of dissections) that may affect the efficacy of DCB.

Association between post-balloon angioplasty dissection and primary patency in complex femoropopliteal artery disease: 2-year clinical outcomes of the AcoArt I trial

OBJECTIVE

To assess the association between post-balloon angioplasty dissection and the mid-term results of the AcoArt I trial evaluating complex femoropopliteal artery disease.

METHODS

The outcome data for 144 patients from the AcoArt 1 trial were reanalysed. These patients were randomly divided into percutaneous transluminal angioplasty (PTA) and drug-coated balloons (DCB) groups. The primary endpoint was the primary patency (PP) rate and clinically-driven target lesion revascularisation at 24 months.

RESULTS

After 24 months of follow-up, the PP rate of dissection cases in the PTA group was lower vs non-dissection cases. In patients receiving a bailout stent for dissection, the PP rate in the PTA group was lower vs the DCB group. Cox regression analysis showed that dissection decreased the PP rate; mild dissection reduced the PP rate as follows: 52%, PTA group and 19%, DCB group. With severe dissection, the PP rate reduction was as follows: 75%, PTA group and 73%, DCB group.

CONCLUSIONS

The mid-term follow-up showed that post-balloon angioplasty dissection reduced the PP rate in the PTA group but not in the DCB group. Additionally, in patients receiving a bailout stent for dissection, the DCB group had a better PP rate than the PTA group.

Predictor analysis of 1-year restenosis after percutaneous transluminal angioplasty for femoropopliteal stenotic lesions using intravascular ultrasound

This retrospective, single-center study evaluated the patency rate and predictors of restenosis after percutaneous transluminal angioplasty (PTA) for femoropopliteal stenotic lesions using intravascular ultrasound. We assessed 78 de novo femoropopliteal stenotic lesions (64 patients; mean age, 73.6 ± 9.4 years; average lesion length, 59.8 mm) that underwent PTA under intravascular ultrasound guidance. The primary endpoint was 1-year primary patency. The 1-year primary patency rate was 63%. The frequency of insulin use was significantly greater (44% vs. 12%, p = 0.005), and lesions were significantly longer (77.8 mm vs. 49.2 mm, p = 0.047) in the restenosis group than in the non-restenosis group. The pre-intervention reference lumen area and minimum lumen area (MLA) were significantly smaller in the restenosis group (reference lumen area: 19.7 ± 6.7 mm² vs. 23.7 ± 7.4 mm², p = 0.017; MLA 3.9 ± 2.8 mm² vs. 5.7 ± 3.9 mm², p = 0.026; respectively). The MLA was significantly smaller and the maximum angle of dissection was significantly larger in the restenosis group (MLA 9.3 mm² vs. 12.3 mm², p = 0.013; maximum angle of dissection: 104.1° vs. 69.6°, p = 0.003; respectively) among post-intervention parameters. Multivariate analysis revealed that the independent predictors of 1-year restenosis were the large post-intervention maximum angle of dissection and insulin use. Per receiver operating curve analysis, the best cut-off value of the post-intervention maximum angle of dissection that predicted 1-year restenosis was 70.2° (sensitivity 72.4%, specificity 63.3%, area under the curve 0.70, p = 0.004). In conclusion, the 1-year primary patency rate after PTA for relatively short stenotic femoropopliteal lesions was 63%. The large post-intervention maximum angle of dissection, measured using intravascular ultrasound, and insulin use were independent predictors of restenosis after PTA.

Outcomes of Drug-Coated Balloon Angioplasty for Isolated Chronic Occlusion of the Popliteal Artery: A Retrospective Single-Institution Study

PURPOSE

To assess the 12-month safety and effectiveness of paclitaxel drug-coated balloon (DCB) for the treatment of patients with isolated chronic occlusions in popliteal arteries and evaluate the risk factors of lesion reocclusion.

MATERIALS AND METHODS

From January 2018 to December 2019, DCB angioplasty was performed in 54 limbs with isolated chronic popliteal artery occlusion of 48 patients (32 men) with a mean age of 71.5 ± 12.1 (range, 50-97) years, mean occlusive length of 6.3 ± 3.0 (range, 1-15) cm, and mean preoperative ankle-brachial index (ABI) of 0.42 ± 0.12 (range, 0.19-0.58). A total of 18.5% (10/54) of lesions were long-segment occlusions involving the entire popliteal artery from P1 to P3. Twenty seven of 54 limbs presented with critical limb ischemia (CLI) with a mean ABI of 0.33 ± 0.10 (range, 0.19-0.51). The primary endpoint was primary patency rate at 12 months. The secondary endpoints included technical success rate, 1-year secondary patency rate, limb salvage rate, and improvement in clinical symptoms. Univariate Cox regression analysis was used to determine the predictors of lesion reocclusion.

RESULTS

The technical success rate was 85.2% (46/54), and bailout stenting was performed in 14.8% (8/54) of lesions. The 12-month primary and secondary patency rates by the Kaplan-Meier estimate were 72.6% and 88.3%, respectively. Two thirds of the reocclusions occurred within 6 months after intervention. No 30-day mortality was observed. The limb salvage rate was 100% during a mean follow-up period of 13 months, and all minor amputations occurred in the limbs presented with CLI. The mean ABI increased from 0.42 before the procedure to 0.73 after the procedure. Patients younger than 60 years and the lesions exhibiting long-segment occlusions present as trending risk factors for lesion reocclusion.

CONCLUSIONS

Paclitaxel DCB angioplasty is safe and effective in managing isolated chronic occlusion of popliteal arteries. Younger patients and long-segment occlusions of the popliteal artery are associated with a relatively higher reocclusion rate after the procedure.

Possible mechanism of late lumen enlargement after treatment for de novo coronary lesions with drug-coated balloon

BACKGROUND

Drug-coated balloon (DCB) treatment for de novo coronary artery disease has demonstrated late lumen enlargement (LLE) in mid-term follow-up and it was considered as clinical benefit; however, its mechanism and the predictive factor remains unclear.

METHODS

This study enrolled 46 consecutive patients (54 lesions) treated with DCB, using intravascular ultrasound (IVUS) at the index procedure and at the 9-month follow-up. We measured IVUS parameters at 1-mm intervals and calculated the mean volume of the external elastic membrane (EEM), lumen, and plaque. We calculated the dissection index (DI) defined as summation of the following points, 2: dissection over EEM, 1: intra-EEM dissection, 0: no dissection at every 1-mm interval, and divided by lesion length.

RESULTS

IVUS showed that there was no flow limiting dissection just after DCB treatment, the mean EEM and lumen volume (LV) had significantly increased while mean plaque volume had significantly decreased at 9 months, and 74.1% lesions exhibited LLE. We divided the patients into three groups according to delta mean LV. Mean EEM volume significantly increased and mean plaque volume significantly decreased in the larger and smaller LLE groups, but not in the non-LLE group. The DI was higher in a descending order in the three groups. The multiple regression analysis demonstrated that the DI was the strongest predictor of the change in mean LV.

CONCLUSIONS

LLE after DCB treatment may be caused by vessel enlargement and plaque regression. The non-flow limiting larger dissection just after DCB treatment may strongly associate with the intending LLE.

Effects of external crushing forces on a novel below-the-knee vascular implant

BACKGROUND

The Tack Endovascular System^® is a novel vascular implant designed to focally treat dissections with low radial force and minimal metal burden. As there are currently no approved below-the-knee (BTK) implants in the USA, a unique, 3-stage model was developed to characterize crush deformation and fracture potential of the Tack Endovascular System in BTK arteries.

METHODS

First, 35 Tack^® implants were deployed bilaterally in the posterior tibial, anterior tibial, and peroneal arteries of 3 cadavers, and clinically relevant external forces were applied to simulate BTK crushing deformation including focal load, leg crossing, and leg bending. Intravascular ultrasound images of the implanted vessels were used to assess the magnitude of artery deformation. Outputs of the cadaver testing were input into a finite element analysis (FEA) model to determine the appropriate conditions for subsequent bench testing. Tack implants were then subjected to increasing crush forces at 30Hz for up to 650,000 cycles at 25% flat plate deformation within the worst-case FEA test condition.

RESULTS

Crush deformation across all arteries ranged from 0% to 23.1%. The posterior tibial artery and large male cadaver exhibited the most vulnerability to external crush forces, while the small female model exhibited the most resistance. No fractures were observed during cadaver or bench testing.

CONCLUSIONS

This study characterized deformation forces in tibial arteries during various loading conditions. Tack implants withstood the loading conditions without fracture within the limits of this ex-vivo human vascular model and in-vitro bench testing.

Balloon Angioplasty of Infrapopliteal Arteries: A Systematic Review and Proposed Algorithm for Optimal Endovascular Therapy

Endovascular revascularization has been increasingly utilized to treat patients with chronic limb-threatening ischemia (CLTI), particularly atherosclerotic disease in the infrapopliteal arteries. Lesions of the infrapopliteal arteries are the result of 2 different etiologies: medial calcification and intimal atheromatous plaque. Although several devices are available for endovascular treatment of infrapopliteal lesions, balloon angioplasty still comprises the mainstay of therapy due to a lack of purpose-built devices. The mechanism of balloon angioplasty consists of adventitial stretching, medial necrosis, and dissection or plaque fracture. In many cases, the diffuse nature of infrapopliteal disease and plaque complexity may lead to dissection, recoil, and early restenosis. Optimal balloon angioplasty requires careful attention to assessment of vessel calcification, appropriate vessel sizing, and the use of long balloons with prolonged inflation times, as outlined in a treatment algorithm based on this systematic review. Further development of specific devices for this arterial segment are warranted, including devices for preventing recoil (eg, dedicated atherectomy devices), treating dissections (eg, tacks, stents), and preventing neointimal hyperplasia (eg, novel drug delivery techniques and drug-eluting stents). Further understanding of infrapopliteal disease, along with the development of new technologies, will help optimize the durability of endovascular interventions and ultimately improve the limb-related outcomes of patients with CLTI.

New Innovations and Devices in the Management of Chronic Limb-Threatening Ischemia

As the number of patients afflicted by chronic limb-threatening ischemia (CLTI) continues to grow, new solutions are necessary to provide effective, durable treatment options that will lead to improved outcomes. The diagnosis of CLTI remains mostly clinical, and endovascular revascularization remains mostly balloon-based. Multiple innovative techniques and technologies are in development or in early usage that may provide new solutions. This review categorizes areas of advancement, highlights recent developments in the management of CLTI and looks forward to novel devices that are currently under investigation.

Current developments in endovascular therapy of peripheral vascular disease

More than 200 million people worldwide have peripheral artery disease (PAD) or its most severe manifestation, critical limb ischemia (CLI). While endovascular treatment has become first line therapy in most cases, a number of challenges remain for optimal treatment of femoropopliteal (FP) or infrapopliteal (IP) disease, especially when these lesions are severely calcified, chronic total occlusions (CTOs) or in-stent restenosis (ISR). Continued evolution of technologies has significantly improved the outcomes for endovascular treatment. A number of new devices are in the pipeline right now, including new paclitaxel eluting stents and balloons, intravascular lithotripsy to treat severely calcified lesions, adventitial delivery of anti-restenotic agents to limit restenosis rates, and percutaneous femoro-popliteal bypass.

Restenosis After Tack Implantation is Associated with Less Complex Patterns of Restenosis Compared to Stent Implantation

In-stent restenosis is complex, difficult to treat and has led to a ‘leave less metal behind’ approach to femoropopliteal intervention. Postangioplasty dissection often requires scaffolding to maintain patency. The Tack Endovascular System provides minimal-metal dissection repair that preserves future treatment options. Tack implants are designed to minimise the inflammation and neointimal hyperplasia that lead to in-stent restenosis. An independent angiographic core laboratory evaluated the restenosis patterns in clinically driven target lesion revascularisation (CD-TLR) during the 12 months following the index procedure in the Tack Optimized Balloon Angioplasty (TOBA) II study and compared these results to those published for nitinol stent implantation. Of the 213 patients in TOBA II, 31 (14.6%) required a CD-TLR. Of these, 28 had angiograms that were evaluated by the core laboratory, and 45.2%, 16.1%, and 29% were graded as Tosaka class I, II and III, respectively. There were no significant differences (p>0.05) in lesion length, degree of calcification or dissection class between the three groups. Tack restenotic lesion classification and analysis show a prevalence of both class I and shorter lesions relative to in-stent restenosis, which may be beneficial to long-term patient outcomes.

Practical Applications of Tack Implants for Infrainguinal Dissection Repair: A Single-Center Experience

Purpose: To assess the practical application and acute outcomes of the Tack Endovascular System for infrainguinal dissection repair in a real-world setting. Materials and Methods: Fifty-one consecutive patients who underwent endovascular revascularization for symptomatic peripheral artery disease and experienced 63 dissections requiring treatment were included in the prospective, single-center, single-arm study between January and June 2019. Thirty-nine (76.5%) lesions were ≥10 cm in length, 33 (64.7%) were totally occluded, and 13 (25.5%) were severely calcified. Fifty-six (88.9%) dissections were classified as severe. Dissections were treated either by means of the 6-F above-the-knee (ATK) or the 4-F below-the-knee (BTK) Tack Endovascular System. Observational outcomes were conditions and scopes of application. Clinical outcomes were acute technical and procedural success as well as safety. Results: Lesions were revascularized with 2.3±0.8 attempts such as standard balloon angioplasty, drug-coated balloon angioplasty, atherectomy, and/or lithotripsy. The Endovascular System was applied in 60 (95.2%) of 63 dissections. All dissections of the femoral artery were treated with the ATK system, and all infrapopliteal dissections with the BTK system. Both systems were successfully applied in popliteal artery dissections. Dissection length predicted the number of Tack implants deployed. Technical success was achieved in 98.3% (59 of 60 dissections). No major adverse event or device-related complication occurred during the procedure. Conclusion: Acute results in effectiveness and safety of the Tack Endovascular System for infrainguinal dissection repair in a real-world setting are promising.

Newly approved devices for endovascular treatment of femoropopliteal disease: a review of clinical evidence

Introduction: Femoropopliteal lesions account for a significant proportion of endovascular interventions for peripheral artery disease. In this manuscript, we review the literature on the application of newly approved devices in the treatment of atherosclerotic lesions at this segment.Areas covered: New drug-coating technologies provide sustained drug-eluting over time and better scaffolds are more resistant to the increased biomechanical stress at the femoropopliteal segment. Thus, the newer drug-eluting stents (i.e. Eluvia®), nitinol interwoven stents (i.e. Supera®), and drug-coated balloons (i.e. Stellarex®) are associated with improved pharmacokinetic profiles and promising primary patency rates. A major predictor of technical failure and restenosis is the calcification of the target vessel. Recently, intravascular lithotripsy of calcified lesions at the femoropopliteal segment with the Shockwave® balloon was introduced as a feasible treatment option for these complex lesions. Finally, we also describe the Tack Endovascular System®, the first-of-its-type, for the repair of post-angioplasty dissections.Expert opinion: The use of innovative stent designs and novel drug-coating, the application of adjunctive intravascular lithotripsy, and the combined use of new devices treating complications might improve the overall outcomes of angioplasty, thereby promising favorable outcomes even for more complex lesions.

Dissections After Infrainguinal Percutaneous Transluminal Angioplasty: A Systematic Review and Current State of Clinical Evidence

Purpose: To systematically review the literature and extract information on the definitions, prevalence, implications, and treatment of dissections after infrainguinal balloon angioplasty, with a goal of summarizing current data and identifying gaps in knowledge to help direct future research. Materials and Methods: A systematic review was performed according to the PRISMA guidelines. Medline (PubMed), Scopus, and Cochrane CENTRAL databases were reviewed for prospective and retrospective studies reporting dissection identification, characterization, incidence, severity, and/or outcomes after infrainguinal balloon angioplasty up to January 30, 2019. The electronic search resulted in 288 studies. From these, 153 full-text articles were assessed, and 51 published from 1964 to 2018 were selected as relevant to this systematic review. Because of the significant between-study differences in lesion characteristics, reporting methods, and lack of core laboratory adjudication, the findings were summarized from each study, but the results were not pooled. Results: The mechanism of percutaneous transluminal angioplasty (PTA) consists of adventitial stretching, medial necrosis, and controlled dissection or plaque fracture. PTA-induced dissections can precipitate pathological high and low shear hemodynamic defects and have been implicated as a contributing factor in procedural complications as well as restenosis at the treatment site. The development of significant dissection after PTA often leads to the use of adjunctive therapies, including stent placement. Despite the ubiquitous nature of dissection after balloon angioplasty (incidence 7.4% to 84%), limited data are available to categorize dissections in the peripheral arteries and direct subsequent treatments to improve vessel patency. With the increased utilization of drug-coated balloon angioplasty, understanding the outcomes of postangioplasty dissection has become increasingly important, as the decision to treat dissections with additional strategies has therapeutic and economic implications. Conclusion: All post-PTA dissections in the femoropopliteal arteries may benefit from a treatment approach that ensures optimal hemodynamics with long-term durability in treated lesions. Further understanding the importance of postangioplasty dissections, along with the development of new technologies, will help optimize the patency of endovascular interventions.

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.

Drug-Coated Balloon Angioplasty in Atherosclerosis Patients With Popliteal Artery Involvement

Purpose: To investigate outcomes of drug-coated balloon (DCB) angioplasty in endovascular interventions including or restricted to the popliteal artery. Methods: A retrospective analysis was conducted of 266 patients [median age 72 years, interquartile range (IQR) 62, 78; 166 men] treated with DCB angioplasty in 281 de novo lesions including the popliteal artery between December 2011 and January 2015 at a single center. The median lesion length was 270 mm (IQR 150, 373). The study outcomes were primary patency and predictors of restenosis [reported as the hazard ratio (HR) with 95% confidence interval (CI)]. Results: The primary patency was 77.4% at a median 12.2 months (IQR 5.7, 18.8). Independent variables associated with restenosis included baseline Rutherford category (HR 1.36, 95% CI 1.05 to 1.77, p=0.02), reference vessel diameter (HR 0.77, 95% CI 0.63 to 0.95, p=0.02), dissection (HR 1.69, 95% CI 1.022.79, p=0.04), and standard nitinol stent use (HR 2.08, 95% CI 1.14 to 3.79, p=0.02). Conclusion: Outcomes after DCB angioplasty in lesions including the popliteal artery were acceptable compared with previous studies. Further investigation with long-term follow-up is needed to confirm these results.

Treatment of infrapopliteal post-PTA dissection with tack implants: 12-month results from the TOBA-BTK study

OBJECTIVES

The Tack implant is designed for focal, minimal metal management of dissections. This study evaluated Tacks for treating postpercutaneous transluminal angioplasty (PTA) dissection in patients with below-the-knee (BTK) arterial occlusive disease.

BACKGROUND

PTA is the most commonly used endovascular treatment for patients with occlusive disease of the BTK vessels. Post-PTA dissection is a significant clinical problem that results in poor outcomes, but currently there are limited treatment options for managing dissections.

METHODS

This prospective, single-arm study evaluated patients with CLI and BTK lesions; 11.4% were Rutherford category (RC) 4 and 88.6% were RC 5. BTK occlusive disease was treated with standard PTA and post-PTA dissections were treated with Tack placement. The primary safety endpoint was a composite of major adverse limb events (MALE) and perioperative death (POD) at 30 days. Other endpoints included: device success; procedure success (vessel patency in the absence of MALE); freedom from clinically driven target lesion revascularization (CD-TLR); primary patency; and changes in RC. Data through 12 months are presented.

RESULTS

Thirty-two of 35 (91.4%) patients had post-PTA dissection and successful deployment of Tacks. Procedural success was achieved in 34/35 (97.1%) patients with no MALEs at 30 days. The 12-month patency rate was 78.4% by vessel, 77.4% by patient, and freedom from CD-TLR was 93.5%. Significant (P < .0001) improvement from baseline was observed in RC (75% of patients improved 4 or 5 steps).

CONCLUSION

Tack implant treatment of post-PTA dissection was safe and effective for treatment of BTK dissections and resulted in reasonable 12-month patency and low rates of CD-TLR.

Emerging and Future Therapeutic Options for Femoropopliteal and Infrapopliteal Endovascular Intervention

Despite recent advances in endovascular therapy for peripheral artery disease, current technologies remain limited by rates of long-term restenosis and application to complex lesion subsets. This article presents data on upcoming therapies, including novel drug-coated balloons, drug-eluting stents, bioresorbable scaffolds, novel drug delivery therapies to target arteries, techniques to limit postangioplasty dissection, and treatment of severely calcified lesions.

Drug-eluting balloons for treatment of SFA and popliteal disease - A review of current status

The endovascular treatment of atherosclerotic disease of the infra-inguinal arteries has changed significantly over the last decades. In an attempt to overcome the high restenosis rates that characterize plain balloon angioplasty and stenting using bare mate stents drug-eluting balloon technology has been applied in the treatment of lesions of the superficial femoral and popliteal artery. This paper will give an overview of the rationale and the technology of drug-eluting balloons and will review currently available data from registries and randomized controlled trials.

Angiographic Dissection Patterns and Patency Outcomes After Balloon Angioplasty for Superficial Femoral Artery Disease

PURPOSE

To investigate the angiographic dissection patterns after balloon angioplasty for superficial femoral artery (SFA) lesions, the clinical outcome associated with each dissection pattern, and the predictive factors for severe dissection.

METHODS

A retrospective, multicenter analysis examined 621 patients (mean age 72.8±9.5 years; 414 men) with 748 symptomatic de novo SFA lesions treated with endovascular therapy. Vessel dissection after the initial balloon angioplasty procedure was graded into 7 types according to a modified version of the coronary artery classification types A to F. Severe vessel dissection patterns were defined as type C or higher. Nitinol stent implantation was performed in 555 (74.2%) lesions for residual stenosis >30% or flow-limiting dissection; 193 lesions (25.8%) were treated with balloon angioplasty only. To determine the clinical outcomes associated with each dissection pattern and identify predictive factors for severe dissection, 2-year follow-up data for the 193 lesions treated with balloon angioplasty only were analyzed for primary patency and clinically driven target lesion revascularization (TLR).

RESULTS

No dissection was found in 16% (120/748) of lesions, and types A and B dissections were seen in 19% (142/748) and 23% (172/748), respectively. Dissection grades above type C were observed in 42% of cases, most frequently type D (180/748, 24%) and less often type C (37/748, 5%), type E (67/748, 9%), and type F (30/748, 4%). The bailout stent implantation rate increased according to dissection severity. At up to 2 years, the severe dissection group (types C-F) showed a significantly lower patency rate (p<0.001) and higher clinically driven TLR (p<0.001) compared to the nonsevere group (no dissection and types A and B dissections). Severe dissection was a significant risk factor for restenosis, which rose progressively from types C to F. Multivariate analysis identified a small reference vessel diameter <5 mm (p=0.001), lesion length >15 cm (p=0.001), and chronic total occlusion (p<0.001) as independent predictors of severe dissection. In subgroup analysis, vessels with a small reference diameter and TASC II C and D lesions had a higher prevalence of severe dissection.

CONCLUSION

Severe dissection was found in 42% of cases after PTA. A small vessel diameter and/or TASC II C/D lesions were related to a high incidence of dissection. Severe dissection during procedures employing balloon angioplasty only could affect long-term patency.

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.

Impact of Angiographic Result After Predilatation on Outcome After Drug-Coated Balloon Treatment of In-Stent Coronary Restenosis

This study investigates clinical outcomes after drug-coated balloon (DCB) treatment for in-stent restenosis (ISR) based on the angiographic result achieved after predilatation and before DCB treatment. Among ISR lesions treated with DCBs, 166 lesions with angiography immediately after predilatation were analyzed. The lesions were divided into 2 groups according to angiographic results after predilatation: (1) "adequate" defined as the presence of Thrombolysis In Myocardial Infarction 3 flow, residual stenosis ≤30%, and no major dissections (n = 98 lesions) or (2) "inadequate" (n = 68 lesions). The reference vessel diameters were larger (2.88 ± 0.39 vs 2.64 ± 0.52 mm, p = 0.001) and lesion lengths shorter in the adequate group (15.4 ± 11.2 vs 19.7 ± 13.9 mm, p = 0.04). During a median follow-up of 808 days, the cumulative target lesion revascularization (TLR) rate was lower in the adequate group (20.3% vs 35.5% at 2 years; p = 0.04). Multivariate analysis indicated that an angiographically inadequate result before DCB treatment was an independent predictor of TLR, even after adjusting for reference vessel diameter and lesion length (hazard ratio 1.99, 95% confidence interval 1.02 to 3.87, p = 0.04). In conclusion, angiographic results after lesion preparation appear to be a good predictor of TLR after DCB treatment for ISR.

Critical appraisal of paclitaxel balloon angioplasty for femoral-popliteal arterial disease

Peripheral arterial disease, particularly critical limb ischemia, is an area with urgent need for optimized therapies because, to date, vascular interventions often have limited life spans. In spite of initial encouraging technical success after femoropopliteal percutaneous transluminal angioplasty or stenting, postprocedural restenosis remains the major problem. The challenging idea behind the drug-coated balloon (DCB) concept is the biological modification of the injury response after balloon dilatation. Antiproliferative drugs administered via DCBs or drug-eluting stents are able to suppress neointimal hyperplasia, the main cause of restenosis. This article reviews the results of DCB treatments of femoropopliteal and infrapopliteal lesions in comparison to standard angioplasty with uncoated balloons. A systematic literature search was performed in 1) medical journals (ie, MEDLINE), 2) international registers for clinical studies (ie, www.clinicaltrials.gov), and 3) abstracts of scientific sessions. Several controlled randomized trials with follow-up periods of up to 5 years demonstrated the efficacy of paclitaxel –DCB technology. However, calcified lesions seem to affect the efficacy of DCB. Combinations of preconditioning methods with DCBs showed promising results. Although the mechanical abrasion of calcium via atherectomy or laser ablation showed favorable periprocedural results, the long-term impact on restenosis and clinical outcome has to be demonstrated. Major advantages of the DCBs are the rapid delivery of drug at uniform concentrations with a single dose, their efficacy in areas wherein stents have been contraindicated until now (ie, bifurcation, ostial lesions), and in leaving no stent scaffold behind. Reinterventions are easier to perform because DCBs leave no metal behind. Various combinations of DCBs with other treatment modalities may prove to be viable options in future. The follow-up results of clinical studies will evaluate the long-term impact of DCBs.

Novel Approaches to the Management of Advanced Peripheral Artery Disease: Perspectives on Drug-Coated Balloons, Drug-Eluting Stents, and Bioresorbable Scaffolds

Introducing anti-restenotic drug-based treatment modalities in femoropopliteal interventions is the potential revolutionizing reperfusion treatment of peripheral artery disease. Durability of recanalization procedures using drug-coated balloons (DCB) and drug-eluting stents (DES) yields in excellent mid-term and long-term technical and clinical outcomes and may be cost saving on the long term as compared to traditional treatment modalities such as plain old balloon angioplasty (POBA) and bare metal nitinol stent implantation. Drug-eluting bioresorbable scaffolds are another drug-based promising treatment option but are still investigational. In particular, DCB provide a novel method to locally deliver paclitaxel into the arterial wall without the need of a chronically implanted delivery system or even if those devices will be indicated, they can be delivered focally. Following the first positive pilot studies, two large pivotal trials have confirmed superiority of DCB over plain old balloon angioplasty (POBA) in the treatment of TASC II A and B femoropopliteal lesions. Even for more complex femoropopliteal lesions such as long lesions and instent restenosis, single center studies and small randomized studies have shown promising mid-term technical and clinical results. For DES, follow-up data for the only commercially available device are now presented up to 5 years with excellent clinical outcome regarding freedom from target lesion revascularization and improvement of walking capacity. This review article summarizes the current knowledge and perspectives of drug-based endovascular treatment modalities in femoropopliteal interventions and discusses still unresolved needs.