Primary Use of Sirolimus-Eluting Stents in the Infrapopliteal Arteries

The Efficacy of Drug-Coated Balloons and Drug-Eluting Stents in Infrapopliteal Revascularization: A Meta-analysis

OBJECTIVE

The study aimed to compare the effectiveness of drug-coated balloon (DCB) and drug-eluting stents (DESs) to standard endovascular techniques like percutaneous transluminal angioplasty (PTA) and bare metal stent (BMS) for treating infrapopliteal artery disease.

METHODS

Including 8 DCB trials and 4 DES trials, this meta-analysis of 12 recent randomized controlled trials (RCTs) is comprehensive. We searched MEDLINE, EMBASE, Science of Web, Cochrane, and PubMed for this meta-analysis. We searched these databases for papers from their inception to February 2023. We also analyzed the references given in the listed studies and any future study that cited them. No language or publication date restrictions were applied to the 12 RCTs. The experimental group includes 8 DCB studies and 4 DES investigations, the DCB group is primarily concerned with the paclitaxel devices, whereas the DES group is preoccupied with the "-limus" devices. Key clinical outcomes in this study were primary patency and binary restenosis rates. This study's secondary outcomes are late lumen loss (LLL), clinically-driven target lesion revascularization (CD-TLR), limb amputation, and all-cause mortality. The evidence quality was assessed using Cochrane risk-of-bias. The PROSPERO registration number for this study is CRD42023462038.

FINDINGS

Only 108 of 1152 publications found satisfied qualifying criteria and contained data. All 13 RCTs have low to moderate bias. Drug-coated balloons and DESs were compared in the excluded study. The analysis comprised 2055 participants from 12 RCTs that met the inclusion criteria, including 1417 DCB patients and 638 DES patients. Drug-coated balloons outperform traditional methods in short-term monitoring of primary patency, binary restenosis, and CD-TLR. The benefits fade over time, and the 2 techniques had similar major amputation rates, mortality rates, and LLL. Drug-eluting stents outperform conventional procedures in primary patency, binary restenosis, and CD-TLR during medium-term to short-term follow-up. Comparing the 2 methods, major and minor amputations, death rate, and LLL were similar.

CONCLUSION

Comparison of DES and DCB with PTA or BMS shows that DES had better follow-up results. DCB has positive short-term results, but long-term effects differ, however, more research is needed to determine when DES and DCB should be used in medical procedures.

CLINICAL IMPACT

The provision of additional evidence to substantiate the advancement of drug-coated balloon (DCB) therapy in the treatment of lower limb arteriosclerosis obliterans, particularly in the below-the-knee area characterized by high calcium load and significant occlusion, is comparable in efficacy to conventional procedures. This finding is advantageous for the progress of interventional revascularization. The advancement and efficacy of DCB have resulted in improved treatment outcomes for medical practitioners in clinical settings. Our research incorporates the most recent randomized experiments.

A systematic review and meta-analysis of sirolimus-eluting stents for treatment of below-the-knee arterial disease

OBJECTIVE

We performed a systematic review and meta-analysis to analyze the efficacy and safety of sirolimus-eluting stents (SESs) in the treatment of below-the-knee (BTK) arterial disease.

METHODS

An electronic literature search was conducted from inception to July 24, 2021. Retrospective, prospective, and randomized studies that had used SESs to treat BTK arterial disease and had reported the primary patency, technical success, target lesion revascularization, and/or mortality were included. Meta-analyses of the proportions were conducted to derive pooled summary statistics of the outcomes. Where Kaplan-Meier curves were provided for primary patency, a meta-analysis of the individual patient data was conducted via a graphic reconstruction tool to estimate primary patency at various follow-up points. For studies comparing SESs and bare metal stents (BMSs), a two-stage meta-analysis was performed to compare the 6-month primary patency of SESs vs BMSs.

RESULTS

Ten studies across 13 publications, including 995 patients, were retrieved for analysis. In the meta-analysis of proportions, across six studies (n = 339 patients), the pooled 6-month primary patency was 87.3% (95% confidence interval [CI], 81.6%-92.1%). Across seven studies (n = 283 patients), the pooled 6-month mortality was 5.4% (95% CI, 1.4%-11.2%). An individual patient data analysis of three studies (n = 282 patients) yielded a primary patency rate of 95.2% (95% CI, 92.7%-97.8%), 82.8% (95% CI, 78.3%-87.6%), 79.8% (95% CI, 75.0%-85.0%), and 79.8% (95% CI, 75.0%-85.0%) at 6, 12, 18, and 24 months, respectively. The 12-month target lesion revascularization rate across four studies (n = 324 patients) was 9.6% (95% CI, 6.4%-13.4%). In the two-stage meta-analysis of 6-month primary patency across three studies (n = 168 patients), the use of SESs was significantly favored over BMSs (risk ratio, 1.28; 95% CI, 1.12-1.46; P < .001).

CONCLUSIONS

The overall evidence suggests that the use of SESs appears to be safe and offers favorable outcomes for BTK arterial disease compared with BMSs.

Comparative performance analysis of interventional devices for the treatment of ischemic disease in below-the-knee lesions: a systematic review and meta-analysis

This meta-analysis aimed to evaluate the device performance of conventional balloon catheters (POBA), drug-coated balloons (DCB), bare-metal stents (BMS), and drug-eluting stents (DES) in below-the-knee (BTK) ischemic lesions with regard to lesion characteristics. Online searches of PubMed, Web of Science, and Cochrane databases (2010–2019) were conducted for each of the test devices. Primary patency rates (pp) and major amputation rates 1 year after the use of each device were analyzed using a random-effects meta-analysis model. Meta-regression analysis was conducted to test associations between the outcomes and lesion characteristics. The analysis included 18 studies reporting on 24 separate cohorts comprising 2,438 patients. DES demonstrated the best pp among the test devices (83.6%; 95% confidence interval = 78.4–88.8%, studies = 8; I² = 66%, P = 0.005). A negative coefficient between lesion length and pp (P = 0.002) was obtained. The ratio of critical limb ischemia (CLI) patients impacted the amputation rates (P = 0.031), whereas no statistically significant difference was found between the devices. DES showed favorable pp in BTK lesions; however, as the lesion lengths using DES were short, pp in long lesions still needs to be evaluated. Shorter lesions gained better pp. A higher ratio of CLI patients resulted in increased amputation rates.

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Global vascular guidelines on the management of chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Incidence and clinical outcomes of the slow-flow phenomenon after infrapopliteal balloon angioplasty

OBJECTIVE

This study investigated the incidence and clinical relevance of the slow-flow phenomenon after infrapopliteal balloon angioplasty.

METHODS

This retrospective, single-center study included 161 consecutive patients with critical limb ischemia (173 limbs) who underwent endovascular treatment for infrapopliteal lesions between January 2012 and May 2015. The overall technical success rate was 88%. Of these lesions, 30 limbs presented with slow flow after angioplasty.

RESULTS

Total occlusion (90% vs 63%; P < .01) and severe calcification (43% vs 8%; P < .01) were more common in the slow-flow group. Kaplan-Meier curve analysis revealed that freedom from major amputation (60% vs 86%; log-rank, P < .01) and wound healing at 2 years (77% vs 91%; log-rank, P = .03) were significantly less common in the slow-flow group. Univariate Cox proportional hazard analysis identified Rutherford class 6 (hazard ratio [HR], 6.4; 95% confidence interval [CI], 2.8-15.8; P < .01), the slow-flow phenomenon (HR, 3.9; 95% CI, 1.6-8.9; P < .01), and hemodialysis (HR, 3.2; 95% CI, 1.2-11.1; P = .02) as independent predictors of major amputation and Rutherford class 6 (HR, 0.3; 95% CI, 0.2-0.6; P < .01), the slow-flow phenomenon (HR, 0.5; 95% CI, 0.3-0.9; P = .02), and pedal arch (HR, 1.6; 95% CI, 1.0-2.5; P = .04) as predictors of wound healing.

CONCLUSIONS

The slow-flow phenomenon after infrapopliteal balloon angioplasty occurred in 18.6% of limbs. This phenomenon may result in poor outcomes.

Drug-eluting stents in the below-knee circulation for patients with critical limb ischemia: when and where

Critical limb ischemia (CLI) is a challenging disease that carries a grim prognosis; limb loss is a frequent occurrence that drastically affects patient mobility and quality of life. The management of this disease in the below-knee circulation is changing rapidly. The frequently encountered technical challenges, long lesions, total occlusions, dense calcifications, are being overcome by increased operator experience and improved technology. A decade ago, balloon angioplasty was the mainstay of treatment, currently, bare-metal stents, drug-eluting stents (DESs), atherectomy devices, and cryoplasty have been explored with varying degrees of success. Over the past few years, DESs in the infrapopliteal vessels have shown promising results. Several prospective randomized studies have been completed, which compare the use of DESs with bare-metal stents or balloon angioplasty for CLI with infrapopliteal disease. This article focuses on the recent evidence-based advances supporting a wider use of DESs in patients with CLI and infrapopliteal disease. The use of DESs in routine and challenging clinical scenarios is also discussed.

Percutaneous transluminal angioplasty versus primary stenting in infrapopliteal arterial disease: a meta-analysis of randomized trials

BACKGROUND

Percutaneous transluminal angioplasty (PTA) and primary stenting are commonly used endovascular therapeutic procedures for the treatment of infrapopliteal arterial occlusive disease. However, which procedure is more beneficial for patients with infrapopliteal arterial occlusive disease is unknown.

METHODS AND RESULTS

We performed a meta-analysis, searching PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, ISI Web of Knowledge, and relevant websites without language or publication date restrictions for randomized trials that compared primary stenting with PTA in patients with infrapopliteal arterial occlusive disease. The keywords were "stents," "angioplasty," "infrapopliteal," "tibial arteries," and "below knee." We selected immediate technical success, primary and secondary patency, limb salvage, and patient survival as the outcomes of this meta-analysis. On the basis of the inclusion criteria, we identified six prospective randomized trials. One-year outcomes did not show any significant differences between the PTA and primary stenting groups, respectively: technical success (93.3% vs 96.2%; odds ratio [OR], 0.59; 95% confidence interval [CI], 0.24-1.47; P = .25), primary patency (57.1% vs 65.7%; OR, 0.95; 95% CI, 0.35-2.58; P = .92), secondary patency (73.5% vs 57.6%; OR, 2.08; 95% CI, 0.81-5.34; P = .13), limb salvage (82.2% vs 87.5%; OR, 0.64; 95% CI, 0.29-1.41; P = .27), and patient survival (84.0% vs 87.5%; OR, 0.79; 95% CI, 0.40-1.55; P = .49).

CONCLUSIONS

For infrapopliteal arterial occlusive disease, primary stenting has the same 1-year benefits as PTA. There is insufficient evidence to support the superiority of either method. Primary stenting is associated with a trend toward higher primary patency and lower secondary patency. Further large-scale prospective randomized trials should produce more reliable results.

Feasibility of endovascular recanalization of occluded infrapopliteal drug-eluting stents

PURPOSE

To investigate the safety and feasibility of percutaneous endovascular recanalization of late total occlusions of infrapopliteal drug-eluting stents (DES).

METHODS

A retrospective study investigated all 408 infrapopliteal stent procedures performed in 367 patients between January 2007 and October 2013 to identify those who underwent percutaneous reintervention for symptomatic infrapopliteal balloon-expandable DES occlusion. The search identified 49 patients with at least one infrapopliteal DES occlusion in 61 (14.9%) of 408 limbs. Seven (14.3%) patients were excluded from the analysis owing to asymptomatic status (n=6) and acute thrombotic occlusion (n=1), leaving 42 patients who underwent endovascular revascularization of occluded stents in 54 limbs. The study's primary outcomes were technical success and complication rates of endovascular recanalization, while secondary outcomes included limb salvage and the identification of factors influencing primary results.

RESULTS

Technical success was 90.7% (49/54 procedures). Technical failure was seen only in cases of stent collapse and overlapping native popliteal artery-infrapopliteal stent occlusion. According to Kaplan-Meier analysis, survival was 89.6%, 81.1%, and 73.5% at 1, 2, and 3 years, respectively, while limb salvage rates were 86.1%, 79.3%, and 72.7% at the same time points. There was 1 (1.8%) case of distal embolization. No factors influencing outcomes could be identified.

CONCLUSION

Percutaneous recanalization of infrapopliteal stent total occlusions is safe and feasible. Technical failure was noted in cases of stent deformation occurring at the pedal artery and in overlapping native popliteal artery-infrapopliteal stent occlusion.

Meta-analysis of outcomes of endovascular treatment of infrapopliteal occlusive disease with drug-eluting stents

PURPOSE

To review emerging evidence regarding the use of bare metal (BMS) vs. drug-eluting stents (DES) in the treatment of infrapopliteal occlusive disease.

METHODS

A systematic review of the literature was undertaken to identify all studies comparing stent treatments of infragenicular vessels in patients with chronic lower limb ischemia. Validated methods to assess the methodological quality of the included studies were applied. Outcome data were pooled, and combined overall effect sizes were calculated using fixed or random effects models. The search identified 4 randomized clinical trials and 2 observational studies reporting on 544 patients (287 treated with DES and 257 treated with BMS). Data are presented as the odds ratio (OR) with 95% confidence interval (CI) and the number-needed-to-treat (NNT).

RESULTS

Primary patency, freedom from target lesion revascularization, and clinical improvement at 1 year were significantly higher in the DES recipients compared to patients treated with BMS (OR 4.511, 95% CI 2.897 to 7.024, p<0.001, NNT 3.5; OR 3.238, 95% CI 2.019 to 5.192, p<0.001, NNT 6.0; and OR 1.792, 95% CI 1.039 to 3.090, p=0.036, NNT 7.3, respectively). No significant differences in limb salvage and overall survival at 1 year were identified between the groups (OR 2.008, 95% CI 0.722 to 5.585, p=0.181; OR 1.262, 95% CI 0.605 to 2.634, p=0.535, respectively). Sensitivity analyses investigating the potential effects of study design and type of DES on the combined outcome estimates validated the results.

CONCLUSION

Our analysis has demonstrated superior short-term results with DES compared with BMS, expressed by increased patency and freedom from target lesion revascularization. The influence of this finding on clinical surrogate endpoints, such as limb salvage, remains unknown.

Infrapopliteal lesion morphology in patients with critical limb ischemia: implications for the development of anti-restenosis technologies

PURPOSE

To angiographically evaluate infrapopliteal arterial lesion morphology in a consecutive series of patients presenting with critical limb ischemia (CLI) and undergoing infrapopliteal angioplasty.

METHODS

A prospective analysis was undertaken of a consecutive series of CLI patients undergoing endovascular therapy in a tertiary referral center in the year 2011. Morphological assessment of baseline angiograms obtained prior to revascularization included lesion length, assessment of calcification using a semi-quantitative scoring system, and reference vessel diameter (RVD) measurement. Delta RVDs were assessed subtracting distal RVDs from proximal RVDs. A total of 197 infrapopliteal lesions in 105 CLI patients (n=106 limbs) were assessed. Of these, 136 lesions were treated by endovascular means.

RESULTS

The average length of treated lesions was 87.1±43.8 mm in stenoses and 124.0±78.3 mm in chronic occlusions (p<0.001). Mean RVD proximal to the lesions was 1.88 mm whereas it was 1.66 mm distal to the lesions (p≤0.03). Mean arterial calcification was 1.15.

CONCLUSION

This prospective angiographic series underlines the complex nature and extensive longitudinal involvement of infrapopliteal lesions in CLI patients. These findings should be taken into consideration for anti-restenosis concepts in this challenging subgroup of peripheral artery disease patients.

Lower limb multilevel treatment with drug-eluting balloons: 6-month results from the DEBELLUM randomized trial

PURPOSE

To report 6-month results of the DEBELLUM (Drug-Eluting Balloon Evaluation for Lower Limb MUltilevel TreatMent) randomized trial to evaluate the efficacy of a drug-eluting balloon (DEB) to reduce restenosis after treatment of multilevel lower limb occlusive disease vs. a conventional angioplasty balloon (AB).

METHODS

Between September 2010 and March 2011, 50 consecutive patients (37 men; mean age 66±4 years) with 122 lesions (96 stenoses and 26 occlusions) of the femoropopliteal (92, 75.4%) or below-the-knee (BTK) arteries (30, 24.6%) were enrolled and randomly assigned to the DEB (25 patients with 57 lesions) or AB (25 patients with 65 lesions) group. Twenty patients presented multilevel lesions. Mean lesion length was 7.5±3.5 cm. Thirty-one (62%) of the patients were Fontaine stage IIb, while 19 (38%) were stage III or IV. DEBs or ABs were used for dilation of de novo lesions or for postdilation after primary stenting (superficial femoral artery only). Patients requiring provisional stenting after angioplasty secondary to flow-limiting dissection or residual stenosis >50% were ineligible. Primary endpoint was late lumen loss at 6 months. Secondary endpoints were target lesion revascularization (TLR), amputation, and thrombosis.

RESULTS

Late lumen loss was lower in the DEB group (0.5±1.4 vs. 1.6±1.7 mm, p<0.01). TLR was necessary in 6.1% of the DEB group vs. 23.6% of the AB group (p=0.02). Comparing the DEB to AB groups, the thrombosis rates were 3.0% vs. 5.2% (p=0.6), and the amputation rates were 3.0% vs. 7.9% (p=0.36). The binary restenosis rates were 9.1% (3/33 limbs) in the DEB group vs. 28.9% (11/38 limbs) in the control group (p=0.03). The ankle-brachial index improved to a greater degree in the DEB group: 0.87±0.22 vs. 0.70±0.13 (p<0.05). The Fontaine stage improved in both groups but more so in patients treated with DEBs (p=0.04).

CONCLUSION

The DEBELLUM trial confirmed the ability of paclitaxel-eluting balloons to reduce restenosis vs. conventional balloons at 6 months after treatment of multilevel (femoropopliteal and BTK) arterial disease in patients affected by claudication and CLI. A lower TLR rate and better clinical outcomes appear to be associated with the use of DEBs regardless of stent placement.

Cost-effectiveness analysis of infrapopliteal drug-eluting stents

INTRODUCTION

There are no cost-utility data about below-the-knee placement of drug-eluting stents. The authors determined the cost-effectiveness of infrapopliteal drug-eluting stents for critical limb ischemia (CLI) treatment.

METHODS

The event-free individual survival outcomes defined by the absence of any major events, including death, major amputation, and target limb repeat procedures, were reconstructed on the basis of two published infrapopliteal series. The first included spot Bail-out use of Sirolimus-eluting stents versus bare metal stents after suboptimal balloon angioplasty (Bail-out SES).The second was full-lesion Primary Everolimus-eluting stenting versus plain balloon angioplasty and bail-out bare metal stenting as necessary (primary EES). The number-needed-to-treat (NNT) to avoid one major event and incremental cost-effectiveness ratios (ICERs) were calculated for a 3-year postprocedural period for both strategies.

RESULTS

Overall event-free survival was significantly improved in both strategies (hazard ratio (HR) [confidence interval (CI)]: 0.68 [0.41-1.12] in Bail-out SES and HR [CI]: 0.53 [0.29-0.99] in Primary EES). Event-free survival gain per patient was 0.89 (range, 0.11-3.0) years in Bail-out SES with an NNT of 4.6 (CI: 2.5-25.6) and a corresponding ICER of 6,518<euro> (range 1,685-10,112<euro>). Survival gain was 0.91 (range 0.25-3.0) years in Primary EES with an NNT of 2.7 (CI: 1.7-5.8) and an ICER of 11,581<euro> (range, 4,945-21,428<euro>) per event-free life-year gained. Two-way sensitivity analysis showed that stented lesion length >10 cm and/or DES list price >1000<euro> were associated with the least economically favorable scenario in both strategies.

CONCLUSIONS

Both strategies of bail-out SES and primary EES placement in the infrapopliteal arteries for CLI treatment exhibit single-digit NNT and relatively low corresponding ICERs.

A prospective randomized multicenter comparison of balloon angioplasty and infrapopliteal stenting with the sirolimus-eluting stent in patients with ischemic peripheral arterial disease: 1-year results from the ACHILLES trial

OBJECTIVES

The study investigated the efficacy and safety of a balloon expandable, sirolimus-eluting stent (SES) in patients with symptomatic infrapopliteal arterial disease.

BACKGROUND

Results of infrapopliteal interventions using balloon angioplasty and/or bare stents are limited by a relatively high restenosis rate, which could be potentially improved by stabilizing the lesion with a SES.

METHODS

Two hundred patients (total lesion length 27 ± 21 mm) were randomized to infrapopliteal SES stenting or percutaneous transluminal balloon angioplasty (PTA). The primary endpoint was 1-year in-segment binary restenosis by quantitative angiography.

RESULTS

Ninety-nine and 101 patients (mean age 73.4 years; 64% diabetics) were randomized to SES and PTA, respectively (8 crossover bailout cases to SES). At 1 year, there were lower angiographic restenosis rates (22.4% vs. 41.9%, p = 0.019), greater vessel patency (75.0% vs. 57.1%, p =0.025), and similar death, repeat revascularization, index-limb amputation rates, and proportions of patients with improved Rutherford class for SES versus PTA.

CONCLUSIONS

SES implantation may offer a promising therapeutic alternative to PTA for treatment of infrapopliteal peripheral arterial disease.

Sirolimus-eluting stents for treatment of infrapopliteal arteries reduce clinical event rate compared to bare-metal stents: long-term results from a randomized trial

OBJECTIVES

The study investigated the long-term clinical impact of sirolimus-eluting stents (SES) in comparison with bare-metal stents (BMS) in treatment of focal infrapopliteal lesions.

BACKGROUND

There is evidence that SES reduce the risk of restenosis after percutaneous infrapopliteal artery revascularization. No data from randomized trials are available concerning the clinical impact of this finding during long-term follow-up.

METHODS

The study extended the follow-up period of a prospective, randomized, multicenter, double-blind trial comparing polymer-free SES with placebo-coated BMS in the treatment of focal infrapopliteal de novo lesions. The main study endpoint was the event-free survival rate defined as freedom from target limb amputation, target vessel revascularization, myocardial infarction, and death. Secondary endpoints include amputation rates, target vessel revascularization, and changes in Rutherford-Becker class.

RESULTS

The trial included 161 patients. The mean target lesion length was 31 ± 9 mm. Thirty-five (23.3%) patients died during a mean follow-up period of 1,016 ± 132 days. The event-free survival rate was 65.8% in the SES group and 44.6% in the BMS group (log-rank p = 0.02). Amputation rates were 2.6% and 12.2% (p = 0.03), and target vessel revascularization rates were 9.2% and 20% (p = 0.06), respectively. The median (interquartile range) improvement in Rutherford-Becker class was -2 (-3 to -1) in the SES group and -1 (-2 to 0) in the BMS group, respectively (p = 0.006).

CONCLUSIONS

Long-term event-free survival, amputation rates, and changes in Rutherford-Becker class after treatment of focal infrapopliteal lesions are significantly improved with SES in comparison with BMS. (YUKON-Drug-Eluting Stent Below the Knee-Randomised Double-Blind Study [YUKON-BTX]; NCT00664963).

Automated photoplethysmography-based determination of ankle-brachial index: a validation study against Doppler sonography

INTRODUCTION

Determination of ankle-brachial-index (ABI) by manual Doppler is well established to screen for lower extremity arterial disease (LEAD) and to predict cardiovascular risk. A new generation of digital-controlled devices promises automated ABI determination. The aim of this study was to determine comparability of automated photoplethysmography (PPG)-derived ABI calculation with the Doppler-ABI algorithm commonly used in cohort studies.

METHODS

Automated PPG-based ABI measurements [Vascular Explorer (VE) and Vicorder (VI)] were recorded from 112 limbs of healthy subjects and 22 limbs of patients with confirmed LEAD. Validity was evaluated on the basis of receiver-operating characteristic (ROC) analysis of clinical status and concordance with Doppler-ABI. Differences between cuff inflation [inf]- and deflation [def]-based method were studied in VE.

RESULTS

PPG-based ABI values were higher compared to Doppler-ABI (VI +0.06, VEinf +0.15, VEdef +0.09, p < 0.001, respectively). The difference was pronounced in pathological (<0.9), borderline (0.9-0.99) and low normal (1.0-1.09) ABI, but less in ABI ≥1.1. However, ROC analysis revealed excellent diagnostic value for LEAD (sensitivity/specificity) and comparable area under the curve at method-adapted ABI thresholds for all methods: Doppler (95/90 %, 0.95), VI (75/96 %, 0.91), VEinf (85/89 %, 0.93) and VEdef (80/98 %, 0.94).

CONCLUSIONS

Digital-controlled PPG-based ABI determination is a useful diagnostic application for LEAD. However, the systematic higher ABI in PPG-based measurement compared to Doppler and remarkable differences between the deflationary and inflationary method are critical for the interpretation of borderline and low normal ABI values where precise reading is essential to detect mild LEAD and subclinical disease and to predict cardiovascular risk.

Below-the-knee drug-eluting stents and drug-coated balloons

Endovascular procedures have evolved to the mainstream treatment of choice for revascularization of infrapopliteal obstructive disease, especially in patients suffering from critical limb ischemia and multiple comorbidities. However, standard balloon angioplasty is limited by the potential of a suboptimal acute outcome due to elastic recoil and/or flow-limiting dissection, followed by neointimal hyperplasia and progressive vascular restenosis even in the case of bare-metal stent use. Drug-eluting stents and drug-coated balloons are emerging endovascular technologies with the promise of significant inhibition of vessel restenosis and improved clinical outcomes. The current review outlines the drug-eluting properties of those instruments and summarizes the currently available clinical data. The authors critically appraise the current status and also provide a glimpse of the near future of endovascular below-the-knee treatments.

Drug-eluting stents for infrapopliteal arterial disease in the setting of critical limb ischemia

Peripheral artery disease is increasingly prevalent with disease presentations ranging from the asymptomatic patient to the patient with an ischemic or threatened lower extremity. The role of the vascular specialist treating the peripheral artery disease patient is to create or maintain straight-line or uninterrupted blood flow to the extremities in order to preserve patient mobility and the ability of the leg to heal in the setting of trauma or infection. Although autologous-vein surgical bypass grafting has long been viewed as the first-line treatment, endovascular approaches have become increasingly popular owing to technological advances, including the advent of drug-eluting stents. The angiographic and clinical results including symptom improvement, wound healing, limb salvage rates, cost considerations and current ongoing clinical research will be discussed.

Stent-assisted below-the-ankle angioplasty for limb salvage

PURPOSE

To report the clinical outcome of stent-assisted below-the-ankle angioplasty for limb salvage in the setting of critical limb ischemia (CLI).

METHODS

A retrospective single-center study was conducted of 40 critical ischemic limbs in 31 patients (mean age 67 ± 8 years, range 46-94) undergoing below-the-ankle stent-assisted angioplasty between April 2006 and April 2009. Coronary bare metal stents were implanted in cases of failed balloon angioplasty due to significant recoil, flow-limiting dissection, abrupt closure, or repeat early reocclusion.

RESULTS

Technical success was 93% (37 limbs), with 3 failures to cross the occlusive lesions. Acute or subacute occlusion was evident in 9 (23%) limbs. The number of runoff vessels increased significantly (p < 0.001) from 0.6 ± 0.8 to 1.8 ± 0.8. During a clinical follow-up of 19.3 ± 11.4 months (range 1-48), the number of repeat interventions for limb salvage was 2.2 ± 1.6 (range 1-9), and a total of 1.6 ± 0.9 stents (range 1-3) were implanted in 8 dorsalis pedis arteries. Acute or subacute stent thrombosis after stenting was observed in 2 of these, and symptomatic in-stent restenosis was detected in 4, which were all treated by repeat intervention. At 6, 12, and 24 months, the freedom from repeat intervention was 39.6%, 39.6%, and 35.2%, respectively. Amputation-free survival was 80.0%, 69.7%, and 62.7%, and limb salvage was 94.7%, 91.4%, and 82.1% at the same time points. Patient survival rates were 77.4%, 71.0%, and 71.0%, respectively. During a mean follow-up of 13.4 ± 12.7 months (range 1-31 months) in 7 of the 8 stented arteries, all examined stents were deformed: stent compression was evident in 5 and stent fracture in 5. However, 7 limbs undergoing dorsalis pedis artery stenting showed complete wound healing; 1 limb had a resistant wound in the heel.

CONCLUSION

Stent-assisted below-the-ankle angioplasty produced a satisfactory clinical outcome but with the need for repeat intervention. Thus, further refinement in endovascular technology is mandatory to reduce the need for repeat interventions and to resolve stent deformity issues.

Sirolimus-eluting stents vs. bare-metal stents for treatment of focal lesions in infrapopliteal arteries: a double-blind, multi-centre, randomized clinical trial

AIMS

Preliminary reports indicate that sirolimus-eluting stents reduce the risk of restenosis after percutaneous infrapopliteal artery revascularization. We conducted a prospective, randomized, multi-centre, double-blind trial comparing a polymer-free sirolimus-eluting stent with a placebo-coated bare-metal stent in patients with either intermittent claudication or critical limb ischaemia who had a de-novo lesion in an infrapopliteal artery.

METHODS AND RESULTS

161 patients were included in this trial. The mean target lesion length was 31 ± 9 mm. The main study endpoint was the 1-year primary patency rate, defined as freedom from in-stent-restenosis (luminal narrowing of ≥50%) detected with duplex ultrasound if not appropriate with angiography. Secondary endpoints included the 6-month primary patency rate, secondary patency rate, and changes in Rutherford-Becker classification after 1 year. Twenty-five (15.5%) patients died during the follow-up period. One hundred and twenty-five patients reached the 1-year examinations. The 1-year primary patency rate was significantly higher in the sirolimus-eluting stent group (80.6%) than in the bare-metal stent group (55.6%, P= 0.004), and the 1-year secondary patency rates were 91.9 and 71.4% (P= 0.005), respectively. The median (interquartile range) change in Rutherford-Becker classification after 1 year was -2 (-3 to -1) in the sirolimus-eluting stent group and -1 (-2 to 0) in the bare-metal stent group, respectively (P= 0.004).

CONCLUSION

Mid-term patency rates of focal infrapopliteal lesions are substantially improved with sirolimus-eluting stent compared with bare-metal stent. Corresponding to the technical results, the changes in Rutherford-Becker classification reveal a significant advantage for the sirolimus-eluting stent.

Primary everolimus-eluting stenting versus balloon angioplasty with bailout bare metal stenting of long infrapopliteal lesions for treatment of critical limb ischemia

PURPOSE

To report the long-term outcomes of a single-center prospective study investigating primary placement of everolimus-eluting metal stents for recanalization of long infrapopliteal lesions compared to a matched historical control group treated with plain balloon angioplasty and provisional placement of bare metal stents in a bailout manner.

METHODS

The study included 81 patients (63 men; mean age 71 years, range 45-85) suffering from critical limb ischemia (CLI) and angiographically proven long-segment (at least 1 lesion >4.5 cm) de novo infrapopliteal artery disease who underwent below-the-knee revascularization with either primary placement of everolimus-eluting stents (n = 47, 51 limbs, 102 lesions) or angioplasty and bailout bare metal stenting (n = 34, 36 limbs, 72 lesions). Clinical and angiographic follow-up was collected at regular time intervals. Primary clinical and angiographic endpoints included patient survival, major amputation-free survival, angiographic primary patency, angiographic binary restenosis (>50%), and overall event-free survival. Results were stratified according to endovascular treatment received. Multivariable Cox proportional hazards regression analysis was applied to adjust for confounding factors of heterogeneity.

RESULTS

Baseline demographics were well matched. No significant differences were identified between the 2 groups with regard to overall 3-year patient survival (82.2% versus 65.7%; p = 0.90) and amputation-free survival (77.1% versus 86.9%; p = 0.20). Up to 3 years, lesions fully covered with everolimus-eluting stents were associated with significantly higher primary patency [hazard ratio (HR) 7.98, 95% CI 3.69 to 17.25, p < 0.0001], reduced binary restenosis (HR 2.94, 95% CI 1.74 to 4.99, p < 0.0001), and improved overall event-free survival (HR 2.19, 95% CI 1.16 to 4.13, p = 0.015) versus the matched historical control group.

CONCLUSION

Primary infrapopliteal everolimus-eluting stenting for CLI treatment significantly inhibits restenosis and improves long-term angiographic patency and overall patient event-free survival compared to balloon angioplasty and bailout bare metal stenting.