Randomized comparison of everolimus-eluting versus bare-metal stents in patients with critical limb ischemia and infrapopliteal arterial occlusive disease. J Vasc Surg. 2012;55:390-398. [PMID: 22169682 DOI: 10.1016/j.jvs.2011.07.099]

"Evolution of Drug-Coated Devices for the Treatment of Chronic Limb Threatening Ischemia"

For patients with Chronic Limb Threatening Ischemia (CLTI), endovascular approaches to revascularization are often employed as a component of multimodality care aimed at limb preservation. However, patients with CLTI are also prone to treatment failure, particularly following balloon angioplasty alone. Drug-coated devices utilizing Paclitaxel were developed to decrease restenosis but have been primarily studied in patients presenting with claudication. In recent years, data have emerged which describe the efficacy of drug-coated devices in the treatment of patients with CLTI. Concurrently, there has been major controversy surrounding the use of drug-coated devices in peripheral arterial disease. A historical narrative of the development and use of drug-coated devices for peripheral arterial disease is presented, along with discussion of major trials. Evidence argues that paclitaxel-based therapies for peripheral arterial disease (PAD) do not increase mortality risk compared to nondrug-coated devices. In CLTI patients, paclitaxel-based balloons and stents provide superior patency and freedom reintervention compared to nondrug-coated devices when treating femoropopliteal disease. However, the use of Paclitaxel-based therapies for below-the-knee (BTK) interventions has not been shown to provide clinically meaningful outcomes compared to nondrug-based therapies. Newer generation antiproliferative agents (Sirolimus, Everolimus) and delivery systems (bioabsorbable scaffolds) hold promise for BTK interventions with early data suggesting decreased rates of major amputation or major adverse limb events.

Drug-eluting devices for lower limb peripheral arterial disease

Peripheral arterial disease is the third leading cause of cardiovascular morbidity after coronary artery disease and stroke. Lower limb peripheral arterial disease commonly involves infrainguinal arteries, may impair walking ability (intermittent claudication) and may confer a significant risk of limb loss (chronic limb-threatening ischaemia), depending on the severity of ischaemia. Endovascular treatment has become the mainstay revascularisation option in both the femoropopliteal and the below-the-knee arterial segments. After crossing and preparing the lesion, treatment results in these arterial segments can be enhanced by using drug-coated devices (drug-eluting stents and drug-coated balloons) that mitigate the occurrence of restenosis. As for other medical devices, the use of drug-eluting devices is based on their demonstrated safety and efficacy profiles when applied in the distinct segments of the lower limb vasculature. In this state-of-the-art narrative review we provide an overview of the safety and efficacy of drug-coated devices when used in the femoropopliteal and below-the-knee arterial segments.

Midterm Outcomes and Predictors of Failure of Lower Extremity Bypass to Para-Malleolar and Pedal Targets

BACKGROUND

The frequency of distal lower extremity bypass (LEB) for infrapopliteal critical limb threatening ischemia (IP-CLTI) has significantly decreased. Our goal was to analyze the contemporary outcomes and factors associated with failure of LEB to para-malleolar and pedal targets.

METHODS

We queried the Vascular Quality Initiative infrainguinal database from 2003 to 2021 to identify LEB to para-malleolar or pedal/plantar targets. Primary outcomes were graft patency, major adverse limb events [vascular reintervention, above ankle amputation] (MALE), and amputation-free survival at 2 years. Standard statistical methods were utilized.

RESULTS

We identified 2331 LEB procedures (1,265 anterior tibial at ankle/dorsalis pedis, 783 posterior tibial at ankle, 283 tarsal/plantar). The prevalence of LEB bypasses to distal targets has significantly decreased from 13.37% of all LEB procedures in 2003-3.51% in 2021 (P < 0.001). The majority of cases presented with tissue loss (81.25. Common postoperative complications included major adverse cardiac events (8.9%) and surgical site infections (3.6%). Major amputations occurred in 16.8% of patients at 1 year. Postoperative mortality at 1 year was 10%. On unadjusted Kaplan-Meier survival analysis at 2 years, primary patency was 50.56% ± 3.6%, MALE was 63.49% ± 3.27%, and amputation-free survival was 71.71% ± 0.98%. In adjusted analyses [adjusted for comorbidities, indication, conduit type, urgency, prior vascular interventions, graft inflow vessel (femoral/popliteal), concomitant inflow procedures, surgeon and center volume] conduits other than great saphenous vein (P < 0.001) were associated with loss of primary patency and increased MALE. High center volume (>5 procedures/year) was associated with improved primary patency (P = 0.015), and lower MALE (P = 0.021) at 2 years.

CONCLUSIONS

Despite decreased utilization, open surgical bypass to distal targets at the ankle remains a viable option for treatment of IP-CLTI with acceptable patency and amputation-free survival rates at 2 years. Bypasses to distal targets should be performed at high volume centers to optimize graft patency and limb salvage and minimize reinterventions.

Network Meta-analysis of Randomised Controlled Trials Comparing the Outcomes of Different Endovascular Revascularisation Treatments for Infra-inguinal Peripheral Arterial Disease Causing Chronic Limb Threatening Ischaemia

OBJECTIVE

The aim of this study was to compare the efficacy of different endovascular revascularisation procedures for treating chronic limb threatening ischaemia (CLTI) using network meta-analysis (NMA).

DATA SOURCES

The databases PubMed and Cochrane Central Register for Controlled Trials were searched on 14 March 2023.

REVIEW METHODS

A NMA of randomised controlled trials (RCTs) reporting the efficacy of different endovascular revascularisation techniques for treating CLTI was performed according to PRISMA guidelines. The primary and secondary outcomes were major amputation and death, respectively. Random effects models were developed and the results were presented using surface under the cumulative ranking curve plots and forest plots. A p value of ≤ .050 was considered statistically significant. The Cochrane collaborative tool was used to assess risk of bias.

RESULTS

A total of 2 655 participants of whom 94.8% had CLTI were included. Eleven trials compared plain balloon angioplasty (PBA) vs. drug coated balloon (DCB) angioplasty (n = 1 771), five trials compared bare metal stent (BMS) vs. drug coated stent (DCS) (n = 466), three trials compared atherectomy vs. DCB (n = 194), two trials compared PBA vs. BMS (n = 70), one trial compared PBA vs. atherectomy (n = 50), and one trial compared BMS vs. DCB (n = 104). None of the revascularisation strategies significantly reduced the risk of major amputation or death compared with PBA. Using the network estimates, GRADE certainty of evidence for improvement in major amputation outcomes for DCB was moderate, for atherectomy and BMS was low, and for DCS was very low compared with PBA. Risk of bias was low in 16 trials, of some concerns in six trials, and high in one trial, respectively.

CONCLUSION

There is no current evidence from RCTs to reliably conclude that BMS, DCB, DCS, or atherectomy are superior to PBA in preventing major amputation and death in patients with CLTI. Larger comparative RCTs are needed to identify the best endovascular revascularisation strategy.

Inhibition effect of copper-bearing metals on arterial neointimal hyperplasia via the AKT/Nrf2/ARE pathway in vitro and in vivo

In-stent restenosis can be caused by the activation, proliferation and migration of vascular smooth muscle cells (VSMCs), which affects long-term efficacy of interventional therapy. Copper (Cu) has been proved to accelerate the endothelialization and reduce thrombosis formation, but little is known about its inhibition effect on the excessive proliferation of VSMCs. In this study, 316L-Cu stainless steel and L605-Cu cobalt-based alloy with varying Cu content were fabricated and their effects on surface property, blood compatibility and VSMCs were studied in vitro and in vivo. CCK-8 assay and EdU assay indicated that the Cu-bearing metals had obvious inhibitory effect on proliferation of VSMCs. Blood clotting and hemolysis tests showed that the Cu-bearing metals had good blood compatibility. The inhibition effect of the Cu-bearing metals on migration of cells was detected by Transwell assay. Further studies showed that Cu-bearing metals significantly decreased the mRNA expressions of bFGF, PDGF-B, HGF, Nrf2, GCLC, GCLM, NQO1 and HO1. The phosphorylation of AKT and Nrf2 protein expressions in VSMCs were significantly decreased by Cu-bearing metals. Furthermore, it was also found that SC79 and TBHQ treatments could recover the protein expressions of phospho-AKT and Nrf2, and their downstream proteins as well. Moreover, 316L-Cu stent proved its inhibitory action on the proliferation of VSMCs in vivo. In sum, the results demonstrated that the Cu-bearing metals possessed apparent inhibitory effect on proliferation and migration of VSMCs via regulating the AKT/Nrf2/ARE pathway, showing the Cu-bearing metals as promising stent materials for long-term efficacy of implantation.

Surgical and Endovascular Therapies for Below-the-Knee Peripheral Arterial Disease: A Contemporary Review

Peripheral arterial disease (PAD) represents one of the most prevalent cardiovascular disease processes and carries a high burden of morbidity and mortality. Patients with chronic limb-threatening ischemia (CLTI), the most severe manifestation of PAD, have the highest rates of cardiovascular morbidity and mortality of the overall PAD population. Patients with below-the-knee (BTK) PAD have an increased propensity toward CLTI due to small-vessel caliber and the frequently comorbid conditions of end-stage renal disease and diabetes mellitus, which tend to affect small artery beds preferentially. For those with BTK PAD with CLTI, the standard of care is revascularization. Early revascularization was performed using surgical bypass. However, endovascular techniques, starting with percutaneous transluminal angioplasty and expanding to the modern armamentarium of adjunctive devices and therapies, have become standard of care for most patients with CLTI due to BTK PAD. In this review, we will discuss the modern surgical and endovascular approaches to revascularization, as well as devices that are currently in development or preapproval study for the treatment of BTK PAD.

Different drugs in drug-eluting stents for peripheral artery disease: a systematic evaluation and Bayesian meta-analysis

Drug-eluting stents (DESs) have become the first-line treatment for symptomatic peripheral arterial disease (PAD). Currently, there are many types of DESs on the market. The same type of DESs has different concentrations, and various drugs in them show uneven efficacy. The selection of DESs remains controversial. This study was aimed at comparing the long-term real-world outcomes of different DESs in the treatment of peripheral arterial occlusive disease (PAOD). The databases including Cochrane Library, Embase, and PubMed were searched with a time frame until March 25, 2023. The primary patency (PP) and target lesion revascularization (TLR) at 6 months were used as the primary endpoints. A total of 32 studies (5467 patients) were eligible. At the six-month follow-up, DES-Evero 1 ug/mm2 ranked first in terms of PP, with a significant difference from BMSs (RR [95% CI] = 1.6). DES-Siro 0.9 ug/mm2, DES-Siro 1.4 ug/mm2, DES-Siro 1.95 ug/mm2, DES-PTX 0.167 ug/mm2, DES-PTX 1 ug/mm2 and covered stents (CSs) showed significantly better PPs than BMSs. In terms of TLR, DES-Siro 0.9 ug/mm2 (0.31) ranked first, and DES-Evero 1 ug/mm2 ranked last. Among the treatment modalities for PAD, different DESs showed overall encouraging results in improving PP and TLR compared with BMSs. DES-Evero 1 ug/mm2 showed the best PP, but it had the highest reintervention rate at 6 months. Sirolimus-eluting stents were not always more effective with higher concentrations of sirolimus. Among various DESs, sirolimus-eluting stents and everolimus-eluting stents were superior to paclitaxel-eluting stents.

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.

Drug-Eluting Resorbable Scaffold versus Angioplasty for Infrapopliteal Artery Disease

BACKGROUND

Among patients with chronic limb-threatening ischemia (CLTI) and infrapopliteal artery disease, angioplasty has been associated with frequent reintervention and adverse limb outcomes from restenosis. The effect of the use of drug-eluting resorbable scaffolds on these outcomes remains unknown.

METHODS

In this multicenter, randomized, controlled trial, 261 patients with CLTI and infrapopliteal artery disease were randomly assigned in a 2:1 ratio to receive treatment with an everolimus-eluting resorbable scaffold or angioplasty. The primary efficacy end point was freedom from the following events at 1 year: amputation above the ankle of the target limb, occlusion of the target vessel, clinically driven revascularization of the target lesion, and binary restenosis of the target lesion. The primary safety end point was freedom from major adverse limb events at 6 months and from perioperative death.

RESULTS

The primary efficacy end point was observed (i.e., no events occurred) in 135 of 173 patients in the scaffold group and 48 of 88 patients in the angioplasty group (Kaplan-Meier estimate, 74% vs. 44%; absolute difference, 30 percentage points; 95% confidence interval [CI], 15 to 46; one-sided P<0.001 for superiority). The primary safety end point was observed in 165 of 170 patients in the scaffold group and 90 of 90 patients in the angioplasty group (absolute difference, -3 percentage points; 95% CI, -6 to 0; one-sided P<0.001 for noninferiority). Serious adverse events related to the index procedure occurred in 2% of the patients in the scaffold group and 3% of those in the angioplasty group.

CONCLUSIONS

Among patients with CLTI due to infrapopliteal artery disease, the use of an everolimus-eluting resorbable scaffold was superior to angioplasty with respect to the primary efficacy end point. (Funded by Abbott; LIFE-BTK ClinicalTrials.gov number, NCT04227899.).

Comparation of drug-eluting stents and control therapy for the treatment of infrapopliteal artery disease: a Bayesian analysis

BACKGROUND

Critical limb-threatening ischaemia is a life-threatening disease which often combines with infrapopliteal arterial disease. Percutaneous transluminal angioplasty (PTA) is recommended as the first-line treatment for infrapopliteal arterial disease. Drug-eluting stent (DES) is another widely used option; however, its long-term therapeutic effect is controversial. The effectiveness of different DES for infrapopliteal arterial disease needs further exploration.

METHODS AND RESULTS

The PubMed, EMBASE, Cochrane Library and Clinical trials were systematically searched from inception to 1 February 2023. Literatures were included if the study was original, peer-reviewed, published in English or Chinese, and contained patients diagnosed with simple infrapopliteal arterial disease or with properly treated combined inflow tract lesions before or during the study procedure. A total of 953 patients, 504 in the DES group and 449 in the PTA/bare-metal stenting (BMS) group, from 12 randomised controlled trials were included in the meta-analysis. The results showed that DES is superior to control group for improving clinical patency, reducing the restenosis rate, and reducing the amputation rate at 6 months, 1 year, and 3 years post-treatment [at 3 years, risk ratio (RR): 1.90, 95% CI 1.23-2.93; RR: 0.87, 95% CI 0.79-0.96; RR: 0.60, 95% CI 0.36-1.00, P =0.049]. In addition, subgroup analyses suggested that DES is superior to BMS and PTA in improving clinical patency and reducing target lesion revascularisation and restenosis rates at 6-month and 1-year post-treatment. The network meta-analysis indicated that sirolimus-eluting stent was superior for improving clinical patency (at 1 year, RR: 0.23, 95% CI 0.08-0.60) and reducing the restenosis rate (at 6 months, RR: 31.58, 95% CI 4.41-307.53, at 1 year, RR: 3.80, 95% CI 1.84-8.87) significantly. However, according to the cumulative rank probabilities test, everolimus-eluting stent may have the lowest target lesion revascularisation rates and amputation rates at 1-year post-treatment (the cumulative rank probability was 77% and 49%, respectively).

CONCLUSIONS

This systematic review and network meta-analysis showed that DES was associated with more clinical efficacy than PTA/BMS significantly. In addition, sirolimus-eluting stent and everolimus-eluting stent may have better clinical benefits.

Primary results of the SAVAL randomized trial of a paclitaxel-eluting nitinol stent versus percutaneous transluminal angioplasty in infrapopliteal arteries

BACKGROUND

Effective and durable options for infrapopliteal artery revascularization for patients with chronic limb-threatening ischemia (CLTI) are limited.

METHODS

The SAVAL trial is a prospective, multicenter, randomized trial of patients with CLTI and infrapopliteal artery lesions with total lesion length ⩽ 140 mm, stenosis ⩾ 70%, and Rutherford category 4-5 assigned 2:1 to treatment with the SAVAL self-expandable paclitaxel drug-eluting stent (DES) or percutaneous transluminal angioplasty (PTA) with an uncoated balloon. The primary effectiveness endpoint was primary vessel patency (i.e., core lab-adjudicated duplex ultrasound-based flow at 12 months in the absence of clinically driven target lesion revascularization or surgical bypass of the target lesion). The primary safety endpoint was the 12-month major adverse event (MAE)-free rate; MAEs were defined as a composite of above-ankle index limb amputation, major reintervention, and 30-day mortality. The endpoints were prespecified for superiority (effectiveness) and noninferiority (safety) at a one-sided significance level of 2.5%.

RESULTS

A total of 201 patients were enrolled and randomly assigned to treatment (N = 130 DES, N = 71 PTA). Target lesion length was 68.1 ± 35.2 mm for the DES group and 68.7 ± 49.2 mm for the PTA group, and 31.0% and 27.6% of patients, respectively, had occlusions. The 12-month primary patency rates were 68.0% for the DES group and 76.0% for the PTA group (Psuperiority = 0.8552). The MAE-free rates were 91.6% and 95.3%, respectively (Pnoninferiority = 0.0433).

CONCLUSION

The SAVAL trial did not show benefit related to effectiveness and safety with the nitinol DES compared with PTA in infrapopliteal artery lesions up to 140 mm in length. Continued innovation to provide optimal treatments for CLTI is needed. (ClinicalTrials.gov Identifier: NCT03551496).

Endovascular Interventions for Peripheral Artery Disease: A Contemporary Review

PURPOSE OF REVIEW

Peripheral artery disease (PAD) is an increasingly prevalent but frequently underdiagnosed condition that can be associated with high rates of morbidity and mortality. While an initial noninvasive approach is the cornerstone of management, revascularization is often pursued for patients with treatment-refractory claudication or chronic limb-threatening ischemia (CLTI). In this review, we discuss the current state of endovascular interventions for PAD and explore the many new emerging technologies.

RECENT FINDINGS

The last decade has resulted in numerous advances in PAD interventions including the ongoing evolution of drug-coated devices, novel approaches to complex lesions, and contemporary evidence from large clinical trials for CLTI. Advances in endovascular management have allowed for increasingly complex lesions to be tackled percutaneously. Future directions for the field include the continued evolution in device technology, continued development of state-of-the-art techniques to revascularization of complex lesions, and increased collaboration between a largely multidisciplinary field.

Meta-analysis of outcomes from drug-eluting stent implantation in infrapopliteal arteries

BACKGROUND

Percutaneous drug-eluting stent implantation (DESI) is an emerging and promising treatment modality for infrapopliteal artery diseases (IPADs). This systematic review and meta-analysis summarizes and quantitatively analyzes the outcomes of DESI in IPADs considering the hazard ratio (HR), which is a more accurate and appropriate outcome measure than the more commonly used relative risk and odds ratio.

AIM

To explore the superiority of drug-eluting stents (DESs) vs traditional treatment modalities for IPADs.

METHODS

The following postoperative indicators were the outcomes of interest: All-cause death (ACD)-free survival, major amputation (MA)-free survival, target lesion revascularization (TLR)-free survival, adverse event (AE)-free survival, and primary patency (PP) survival. The outcome measures were then compared according to their respective HRs with 95% confidence intervals (CIs). The participants were human IPAD patients who underwent treatments for infrapopliteal lesions. DESI was set as the intervention arm, and traditional percutaneous transluminal angioplasty (PTA) with or without bare metal stent implantation (BMSI) was set as the control arm. A systematic search in the Excerpta Medica Database (Embase), PubMed, Web of Science, and Cochrane Library was performed on November 29, 2022. All controlled studies published in English with sufficient data on outcomes of interest for extraction or conversion were included. When studies did not directly report the HRs but gave a corresponding survival curve, we utilized Engauge Digitizer software and standard formulas to convert the information and derive HRs. Then, meta-analyses were conducted using a random-effects model.

RESULTS

Five randomized controlled trials and three cohort studies involving 2639 participants were included. The ACD-free and MA-free survival HR values for DESI were not statistically significant from those of the control treatment (P > 0.05); however, the HR values for TLR-free, AE-free, and PP-survival differed significantly [2.65 (95%CI: 1.56-4.50), 1.57 (95%CI: 1.23-2.01), and 5.67 (95%CI: 3.56-9.03), respectively].

CONCLUSION

Compared with traditional treatment modalities (i.e., PTA with or without BMSI), DESI for IPADs is superior in avoiding TLR and AEs and maintaining PP but shows no superiority or inferiority in avoiding ACD and MA.

Meta-analysis of outcomes from drug-eluting stent implantation in infrapopliteal arteries

BACKGROUND

Percutaneous drug-eluting stent implantation (DESI) is an emerging and promising treatment modality for infrapopliteal artery diseases (IPADs). This systematic review and meta-analysis summarizes and quantitatively analyzes the outcomes of DESI in IPADs considering the hazard ratio (HR), which is a more accurate and appropriate outcome measure than the more commonly used relative risk and odds ratio.

AIM

To explore the superiority of drug-eluting stents (DESs) vs traditional treatment modalities for IPADs.

METHODS

The following postoperative indicators were the outcomes of interest: All-cause death (ACD)-free survival, major amputation (MA)-free survival, target lesion revascularization (TLR)-free survival, adverse event (AE)-free survival, and primary patency (PP) survival. The outcome measures were then compared according to their respective HRs with 95% confidence intervals (CIs). The participants were human IPAD patients who underwent treatments for infrapopliteal lesions. DESI was set as the intervention arm, and traditional percutaneous transluminal angioplasty (PTA) with or without bare metal stent implantation (BMSI) was set as the control arm. A systematic search in the Excerpta Medica Database (Embase), PubMed, Web of Science, and Cochrane Library was performed on November 29, 2022. All controlled studies published in English with sufficient data on outcomes of interest for extraction or conversion were included. When studies did not directly report the HRs but gave a corresponding survival curve, we utilized Engauge Digitizer software and standard formulas to convert the information and derive HRs. Then, meta-analyses were conducted using a random-effects model.

RESULTS

Five randomized controlled trials and three cohort studies involving 2639 participants were included. The ACD-free and MA-free survival HR values for DESI were not statistically significant from those of the control treatment (P > 0.05); however, the HR values for TLR-free, AE-free, and PP-survival differed significantly [2.65 (95%CI: 1.56-4.50), 1.57 (95%CI: 1.23-2.01), and 5.67 (95%CI: 3.56-9.03), respectively].

CONCLUSION

Compared with traditional treatment modalities (i.e., PTA with or without BMSI), DESI for IPADs is superior in avoiding TLR and AEs and maintaining PP but shows no superiority or inferiority in avoiding ACD and MA.

Advanced Endovascular Techniques for Limb Salvage

As the number of patients affected by peripheral arterial disease continues to increase, new technical approaches and devices have been developed to provide effective and durable treatment options that will lead to improved outcomes. While the mainstay of endovascular intervention remains mostly balloon-based, several innovative techniques and technologies are in development that may provide new solutions. This review highlights recent endovascular advancements in the management of chronic limb-threatening ischemia and additional adjunctive devices that are needed to improve lesion patency, reduce the need for reintervention, and lead to better patient-centered functional outcomes.

Evaluation of an Infrapopliteal Drug-Eluting Resorbable Scaffold: Design Methodology for the LIFE-BTK Randomized Controlled Trial

Background

Critical limb-threatening ischemia (CLTI) is a severe condition characterized by rest pain and ischemic tissue loss that affects 5% to 10% of people with peripheral artery disease. In the United States, there are few Food and Drug Administration-approved devices for the primary treatment of arteries below-the-knee (BTK). Unfortunately, all suffer from high restenosis rates due to intimal hyperplasia, elastic recoil, and untreated dissection because of a lack of scaffolding. The Esprit BTK system is a resorbable, drug-eluting scaffold device with the potential to address an unmet need in people suffering from CLTI because of infrapopliteal atherosclerosis. The LIFE-BTK (pivotaL Investigation of saFety and Efficacy of drug-eluting resorbable scaffold treatment-Below The Knee) randomized controlled trial (RCT) is a prospectively designed premarket evaluation of the Esprit BTK drug-eluting resorbable scaffold used in the treatment of those patients.

Methods

The LIFE-BTK trial enrolled 261 subjects with CLTI for the RCT and a further 7 subjects for a pharmacokinetic substudy. The objective of the RCT was to evaluate the safety and efficacy of the Esprit BTK scaffold compared to percutaneous transluminal angioplasty. The primary efficacy end point was a composite of limb salvage and primary patency at 12 months. The primary safety end point is freedom from major adverse limb events and peri-operative death at 6 months and 30 days, respectively. Clinical follow-up care is planned for 5 years.

Conclusions

Novel devices must be tested in RCTs to evaluate their safety and efficacy compared to the standard of care if we are to improve outcomes for this challenging group of patients.

Below-the-Knee Stents and Scaffolds: A Comprehensive Review

Below-the-knee intervention of chronic limb-threatening ischemia is an area of increasing interest. Due to lower morbidity and possibly better clinical outcomes, endovascular techniques have become increasingly important in this patient population many of who have limited surgical options. This article serves as a review of existing stent and scaffolding devices utilized for infrapopliteal disease. The authors will additionally discuss current indications and review studies that are investigating novel materials used in treating infrapopliteal arterial disease.

Effectiveness and Safety of Atherectomy versus Plain Balloon Angioplasty for Limb Salvage in Tibioperoneal Arterial Disease

PURPOSE

To evaluate the effectiveness and safety of atherectomy versus plain balloon angioplasty (POBA) for treatment of critical limb ischemia (CLI) due to tibioperoneal arterial disease (TPAD).

MATERIALS AND METHODS

Patients enrolled in the Vascular Quality Initiative registry who had CLI (Rutherford Class 4-6) and underwent atherectomy versus POBA alone for isolated TPAD were retrospectively identified. Of eligible patients, a cohort of 2,908 patients was propensity matched 1:1 by clinical and angiographic characteristics. The atherectomy group comprised 1,454 patients with 2,183 arteries treated, and the POBA group comprised 1,454 patients with 2,141 arteries treated. The primary study endpoint was major ipsilateral limb amputation. Secondary endpoints were minor ipsilateral amputations, any ipsilateral amputation, primary patency, target vessel reintervention (TVR), and wound healing at 12 months.

RESULTS

The median follow-up period was 507 days, the mean patient age was 69 years ± 11.7, and the mean occluded length was 6.9 cm ± 6.5. There was a trend toward higher technical success rates with atherectomy than with POBA (92.9% vs 91.0%, respectively; P = .06). The rates of major adverse events during the procedure were not significantly different. The 12-month major amputation rate was similar in the atherectomy and POBA groups (4.5% vs 4.6%, respectively; P = .92; odds ratio, 0.97; 95% CI, 0.68-1.37). There was no difference in 12-month TVR (17.9% vs 17.8%; P = .97) or primary patency (56.4% vs 54.5%; P = .64) between the atherectomy and POBA groups.

CONCLUSIONS

In a large national registry, treatment of CLI from TPAD using atherectomy versus POBA showed no significant differences in procedural adverse events, major amputations, TVR, or vessel patency at 12 months.

Underutilization of Drug-Eluting Stents in Infrapopliteal Intervention for Chronic Limb-Threatening Ischemia

PURPOSE

Multiple randomized clinical trials have shown superiority of drug-eluting stents (DES) over bare-metal stents (BMS) for infrapopliteal disease. However, real-world data on DES utilization and outcomes in infrapopliteal chronic limb-threatening ischemia (CLTI) patients are unknown.

MATERIALS AND METHODS

We utilized the Nationwide Readmission Database (NRD) from 2016 to 2017 to extract patients undergoing infrapopliteal intervention with stents (BMS and DES) for CLTI using appropriate ICD-10 codes. Multilevel logistic regression with hospital ID as random effect was used to assess DES utilization. Primary outcome was the composite of target limb major amputation (TLmajA) and target limb revascularization (TLR). Multivariate Cox-proportional hazard regression was used to adjust for confounders.

RESULTS

Our study included a total of 1817 patients. Of these patients, 1056 patients (58.1%) received DES; DES utilization was stable (relative change: +2.5%, p-trend: 0.867) between 2016 and 2017 and was higher in teaching hospitals (adjusted odds ratio [aOR] = 1.28, 95% CI = 1.03-1.61, p=0.029] and medium (aOR = 3.13, 95% CI = 2.17-4.55, p≤0.001) and large (aOR = 1.56, 95% CI = 1.14-2.17, p=0.005) bed-sized hospitals. Inter-class correlation was 0.44 suggesting ~44% variation in DES utilization between any 2 random hospitals; DES was associated with lower rate of the primary composite outcome (aHR = 0.75, 95% CI = 0.62-0.92, p=0.004) compared with BMS.

CONCLUSION

In patients undergoing infrapopliteal intervention for CLTI, DES demonstrated significant underutilization despite supportive evidence of their superiority compared with BMS; DES was associated with improvement in the primary composite outcome compared with BMS.

Polymer Free Amphilimus Drug Eluting Stent for Infrapopliteal Arterial Disease in Patients with Critical Limb Ischemia: A New Device in the Armamentarium

Background and Objectives: Endovascular technologies have significantly improved the outcome of patients with critical limb ischemia (CLI). Drug eluting stents (DES) have documented their efficacy against percutaneous transluminal angioplasty (PTA) and bare metal stents (BMS) in infrapopliteal arterial occlusive disease. However, late in-stent neoatherosclerosis may lead to vascular lumen loss and eventually thrombosis. Polymer free DES constitute a new technology aiming to improve long term patency which their action is still under investigation. The purpose of this study is to report the mechanism of action and to provide a literature review of a novel polymer free amphilimus eluting stent (Cre8, Alvimedica, Instabul, Turkey) in infrapopliteal arterial disease. Methods: Publications listed in electronic databases, European Union Drug Regulating Authorities Clinical Trials Database, as well as scientific programmes of recent interventional vascular conferences were searched. Three studies were included. We analyzed primary and secondary patency, major amputation rate, freedom from CD-TLR, and mortality. Results: Cre8 was implanted in 79 patients with CLI. Most of the patients (n = 65) were Rutherford class 5-6 (82.3%), and diabetes mellitus (DM) was present in 66 patients (83.5%). Mean primary patency was 82.5% at 12 months. Mean lesion stented length was 20 mm and 35 mm in two studies. Mean limb salvage was 91.3% at 12 months. Freedom from CD-TLR was reported in two out of the three studies and was 96% and 83.8%. Mortality was 15% and 23.8% in the same studies, whilst it was not reported in one study. Conclusion: Stenting of infrapopliteal arteries with Cre8 is safe and feasible in patients with CLI and diabetes. All studies have shown very good primary patency and freedom from CD-TLR at 12 and 24 months. Larger observational prospective studies and randomized trials are necessary to establish long term effectiveness and clinical outcomes using the non-polymer Cre8 DES.

The efficacy and safety of different endovascular modalities for infrapopliteal arteries lesions: A network meta-analysis of randomized controlled trials

Background

Endovascular treatment has become the first-line therapy for infrapopliteal artery occlusive disease (IPOD), while the optimal endovascular method remains to be determined. We performed a network meta-analysis (NWM) of randomized controlled trials (RCTs) to simultaneously compare the outcomes of different endovascular modalities for IPOD.

Methods and results

The Pubmed, Embase, and Cochrane databases were used as data sources. The NWM approach used random-effects models based on the frequentist framework. In total, 22 eligible RCTs (44 study arms; 1,348 patients) involving nine endovascular modalities or combinations [balloon angioplasty (BA), drug-coated balloon (DCB), drug-eluting stent (DES), atherectomy device + BA (AD + BA), AD + DCB, balloon-expandable bare metal stent (BMS), self-expanding stent (SES), absorbable metal stents (AMS), and inorganics-coated stent (ICS)] were included. BA had a lower 12-month primary patency rate than DCB (RR 0.50, CI 0.27, 0.93) and AD + DCB (RR 0.34, CI 0.12, 0.93). AD + DCB decreased 6-month TLR compared with AMS (RR 0.15, CI 0.03, 0.90), and DES decreased it compared with BMS (RR 0.25, CI 0.09, 0.71). DCB had a lower 6-month TLR rate than AMS (RR 0.26, CI 0.08, 0.86) and BA (RR 0.51, CI 0.30, 0.89). BA had a higher 12-month TLR rate than DCB (RR 1.76, CI 1.07, 2.90). According to the value of the surface under the cumulative ranking curve (SUCRA), AD + DCB was considered the best treatment in terms of primary patency at 6 months (SUCRA = 87.5) and 12 months (SURCA = 91). AD + BA was considered the best treatment in terms of 6-month TLR (SUCRA = 83.1), 12-month TLR (SURCA = 75.8), and 12-month all-cause mortality (SUCRA = 92.5). In terms of 12-month major amputation, DES was considered the best treatment (SUCRA = 78.6), while AD + DCB was considered the worst treatment (SUCRA = 28.8). Moreover, AD + BA always ranks higher than AD + DCB in the comparison including these two combinations. Subgroup analyses of modalities without stenting did not significantly change the primary outcomes.

Conclusion

ADs showed noteworthy advantages in multiple terms for IPOD except for 12-month major amputation. AD + BA may be a better method for IPOD than AD + DCB. The efficacy and safety of ADs are worthy of further investigation.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42022331626].

One-year outcomes following primary stenting of infrapopliteal steno-occlusive arterial disease using a non-polymer sirolimus-eluting stent: Results from a prospective single-centre cohort study

Background

Clinical outcomes using new generation drug-eluting stents designed specifically for infrapopliteal disease are not widely available, especially in comparison to paclitaxel-based therapies. This series reports 1-year outcomes in patients with diabetes and chronic limb threatening ischaemia (CLTI) undergoing angioplasty, with a sirolimus-eluting tibial stent (Cre8, Alvimedica, Turkey), evaluating the feasibility, safety, and efficacy of this new device. Outcomes were compared to matched patients undergoing infrapopliteal angioplasty using a paclitaxel-coated balloon (DCB).

Patients and Methods

Patients with diabetes and CLTI requiring infrapopliteal intervention were recruited prospectively to undergo angioplasty and primary stenting using the Cre8 sirolimus-eluting stent between January 2018 and October 2020 at a single high-volume vascular centre; outcomes were compared to a group of patients with diabetes and CLTI who had undergone infrapopliteal angioplasty using a DCB. All patients were followed up for at least 12 months using a uniform protocol with duplex ultrasound and examination. The primary outcome measure was target lesion patency (<50% restenosis). Clinically driven target lesion revascularisation (CD-TLR), amputations, Rutherford stage, and mortality were also recorded.

Results

A total of 54 patients (61 target lesions; median age: 69 years, 74% male) were included [27 with the Cre8 device (main group) vs. 27 with a DCB (historical controls)]. Primary patency at 12 months was 81% in the Cre8 group vs. 71% in the control group (p = 0.498). Overall, four (15%) patients in the Cre8 group vs. three (11%) patients in the control group underwent a major amputation within 12 months (p = 1.0). CD-TLR (all endovascular) did not differ between groups at 12 months (4% Cre8 vs. 10% control group, p = 0.599). Rutherford stage improvement at 12 months was superior for the Cre8 group (52% vs. 15% improved by at least one stage, p = 0.039). One-year mortality was 15% in the Cre8 group vs. 22% in the control group, p = 0.726.

Conclusions

Primary stenting with the Cre8 stent is feasible and safe in diabetic patients and CLTI. When compared to patients undergoing angioplasty with a DCB, there were no significant differences regarding primary patency, CD-TLR, major amputations, and mortality at 12 months. Those treated with a Cre8 stent were more likely to have an improvement in their Rutherford stage.

Drug-Eluting Stents

Endovascular revascularization strategies have advanced tremendously over the years and are now often considered first line for treatment of peripheral arterial disease. Drug-eluting stents (DESs) have been developed as one of the tools to overcome the limitations of elastic recoil and neointimal hyperplasia observed with balloon angioplasty and bare metal stents. While these stents have been extremely successful in coronary revascularization, they have not translated as effectively to the peripheral arteries which differ in their unique mechanical environments and differences in vessel and lesion composition. DESs, through their embedded pharmaceutical agent, seek to inhibit vascular smooth muscle cell (VSMC) proliferation and migration. Paclitaxel, sirolimus, and its derivatives (-limus family) achieve VSMC inhibition through unique mechanisms. Several clinical trials have been performed to evaluate the use of DES in the femoropopliteal and infrapopliteal territory and have demonstrated overall decrease in revascularization rates and improved clinical outcomes.

Twenty-Four Month Results of Tack-Optimized Balloon Angioplasty Using the Tack Endovascular System in Below-the-Knee Arteries

PURPOSE

To report 24 month safety and efficacy of the Tack Endovascular System for treatment of post-percutaneous transluminal angioplasty (PTA) infrapopliteal dissections in patients with critical limb-threatening ischemia (CLTI).

MATERIALS AND METHODS

The Tack-Optimized Balloon Angioplasty (TOBA) II below-the-knee (BTK) study was a prospective, multicenter, single-arm evaluation of the Tack Endovascular system for post-PTA infrapopliteal dissection repair. Patients with Rutherford Clinical Category (RC) 3 to 5 and a post-PTA dissection(s) of the BTK arteries were enrolled. The 30 day primary safety endpoint was a composite of major adverse limb events (MALE) and all-cause perioperative death (POD). The primary effectiveness endpoint was a composite of MALE at 6 months and 30 day POD. Outcomes were assessed as observational endpoints at 24 months.

RESULTS

Tack-Optimized Balloon Angioplasty II BTK enrolled 233 patients; all patients had a post-PTA dissection(s) and received ≥1 Tack implant (range, 1-16). Mean age was 74.4±10.0 years and 67.4% were men. Most patients had CLTI (RC 3: 16.3%; RC 4/5: 83.7%). Mean target lesion length was 80±49 mm. Moderate to severe calcium was present in 89 (35.8%) lesions and total occlusions were present in 118 (47.6%) lesions. Kaplan-Meier freedom from MALE at 24 months + POD at 30 days was 92.2% and 24 month freedom from clinically-driven target lesions revascularization was 73.6%. Kaplan-Meier target limb salvage was 95.7% and amputation-free survival was 75.4%. Improvements in functional status and quality of life were observed through 24 months.

CONCLUSION

The TOBA II BTK study demonstrated sustained safety and efficacy through 24 months in patients treated for post-PTA dissection(s) of BTK lesions.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02942966.

Cost-Effectiveness of Drug-Coated Balloon Angioplasty Versus Conventional Balloon Angioplasty for Treating Below-the-Knee Arteries in Chronic Limb-Threatening Ischemia: The SINGA-PACLI Trial

PURPOSE

Drug-coated balloon angioplasty (DCBA) has been studied as a potentially superior option compared to conventional percutaneous transluminal angioplasty (PTA) in treating below-the-knee (BTK) arteries in chronic limb-threatening ischemia (CLTI). The aim of this study is to examine the cost-effectiveness of DCBA versus PTA in BTK arteries based on a randomized controlled trial.

MATERIAL AND METHODS

A prospective economic study was embedded in a randomized controlled trial of 138 patients with CLTI. Resource use and health outcomes were assessed at baseline, and at 3, 6 and 12 months post-intervention. Costs were calculated from a societal perspective and health outcomes measured using quality-adjusted life years with probabilistic sensitivity analysis performed to account for subject heterogeneity.

RESULTS

Compared with participants randomized to receive PTA, participants randomized to DCBA gained an average baseline-adjusted quality-adjusted life years (QALYs) of .012 while average total costs were USD$1854 higher; this translates to an incremental cost-effectiveness ratio (ICER) of US$154,500 additional cost per QALY gained. However, the estimate of ICER had substantial variance with only 48% of bootstrap ICERs meeting a benchmark threshold of US$57,705 (the average gross domestic product (GDP) per capita of Singapore).

CONCLUSION

The use of DCBA in BTK arteries in CLTI patients was not cost-effective compared with PTA.

LEVEL OF EVIDENCE

2, Randomized trial.

Drug-Eluting Stents Versus Conventional Endovascular Therapies in Symptomatic Infrapopliteal Peripheral Artery Disease: A Meta-analysis

Background

Balloon angioplasty is the standard endovascular treatment for symptomatic infrapopliteal peripheral artery disease (PAD). However, recent trials have studied the effectiveness of drug-eluting stents (DES) for infrapopliteal PAD.

Objective

This study investigated the use of DES compared with standard endovascular techniques for treatment of infrapopliteal artery disease.

Methods

This is a comprehensive systematic review and meta-analysis of 9 recent randomized controlled trials. The primary clinical outcome assessed was primary patency. The secondary outcomes were target lesion revascularization (TLR), major limb amputation, and all-cause mortality.

Results

A total of 945 patients met the inclusion criteria. Patients treated with DES were found to have increased primary patency than control at maximum follow-up (hazard ratio [HR] 2.17, 95% confidence interval [CI] 1.58-2.97, P < .0001, I2 = 62%). A similar result was seen in the subgroup of patients with critical limb ischemia (HR 2.58, 95% CI 1.49-4.49, P = .0008, I2 = 75%). DES were associated with significantly lower rates of TLR than control at maximum follow-up (HR 0.48, 95% CI 0.33-0.68, P < .0001; I2 = 11%). There was no statistical difference between DES versus control in rates of major limb amputation and mortality.

Conclusions

DES have superior primary patency and TLR rates with no difference in amputation and all-cause mortality rates compared with conventional endovascular therapies in patients with infrapopliteal PAD.

Endovascular treatment of high-risk peripheral vascular occlusive lesions: a review of current evidence and emerging applications of intravascular lithotripsy, atherectomy, and paclitaxel-coated devices

Endovascular treatment of peripheral arterial disease has evolved and expanded rapidly over the last 20 years. New technologies have increased the diversity of devices available and have made it possible to approach even the most challenging and high-risk lesions using endovascular techniques. In this review, we examine the clinical evidence available for several categories of endovascular devices available to treat peripheral arterial disease, including intravascular lithotripsy, atherectomy, and drug-coated devices. The best application for some technologies, such as intravascular lithotripsy and atherectomies, have yet to be identified. In contrast, drug-coated devices have an established role in patients at high risk for long-term failure, but have been the subject of much controversy, given recent concerns about possible adverse effects of paclitaxel. Future investigation should further assess these technologies in patients with complex disease using updated staging systems and outcomes with direct clinical relevance, such as functional improvement, wound healing, and freedom from recurrent symptoms.

Evidence-Experience Gap and Future Perspective on the Treatment of Peripheral Artery Disease

Peripheral artery disease (PAD) is a systemic disease associated with impaired limb function, poor quality of life, and increased cardiovascular morbidity. Its incidence has been dramatically increasing over years because of the emergence of an aging society and the increase in the number of patients with atherosclerotic risk factors. The clustering of these risk factors promotes disease development, reportedly leading to the differential location of atherosclerotic lesions in lower extremity arteries. The clinical presentations of PAD include intermittent claudication and chronic limb-threatening ischemia (CLTI). PAD is associated with a high risk of mortality and morbidity from both cardiovascular and limb events. The therapeutic goals for patients with PAD include 1) relief from PAD-related limb symptoms, 2) the prevention of new-onset and the development and recurrence of PAD, and 3) the prevention of concomitant adverse events due to coronary artery disease (CAD) and cerebrovascular disease (CVD). There are several types of antithrombotic agents, and their main role in patients with PAD is to reduce systemic events mainly including cardiovascular and lower extremity-related events. Currently, the efficacy of direct oral anticoagulant (DOAC) is also suggested by recent clinical trials. Although endovascular therapy (EVT) has been a first-line revascularization strategy for symptomatic PAD, whether clinical outcomes after EVT are comparable to those after surgical bypass therapy remains inconclusive.

Implementation of innovative medical technologies in German inpatient care: patterns of utilization and evidence development

BACKGROUND

Innovative medical technologies are commonly associated with positive expectations. At the time of their introduction into care, there is often little evidence available regarding their benefits and harms. Accordingly, some innovative medical technologies with a lack of evidence are used widely until or even though findings of adverse events emerge, while others with study results supporting their safety and effectiveness remain underused. This study aims at examining the diffusion patterns of innovative medical technologies in German inpatient care between 2005 and 2017 while simultaneously considering evidence development.

METHODS

Based on a qualitatively derived typology and a quantitative clustering of the adoption curves, a representative sample of 21 technologies was selected for further evaluation. Published scientific evidence on efficacy/effectiveness and safety of the technologies was identified and extracted in a systematic approach. Derived from a two-dimensional classification according to the degree of utilization and availability of supportive evidence, the diffusion patterns were then assigned to the categories "Success" (widespread/positive), "Hazard" (widespread/negative), "Overadoption" (widespread/limited or none), "Underadoption" (cautious/positive), "Vigilance" (cautious/negative), and "Prudence" (cautious/limited or none).

RESULTS

Overall, we found limited evidence on the examined technologies regarding both the quantity and quality of published randomized controlled trials. Thus, the categories "Prudence" and "Overadoption" together account for nearly three-quarters of the years evaluated, followed by "Success" with 17%. Even when evidence is available, the transfer of knowledge into practice appears to be inhibited.

CONCLUSIONS

The successful implementation of safe and effective innovative medical technologies into practice requires substantial further efforts by policymakers to strengthen systematic knowledge generation and translation. Creating an environment that encourages the conduct of rigorous studies, promotes knowledge translation, and rewards innovative medical technologies according to their added value is a prerequisite for the diffusion of valuable health care.

Retrograde Revascularization of Tibial Arteries in Patients with Critical Limb Ischemia: Plantar-Arch Versus Transpedal Approach

PURPOSE

To compare retrograde plantar-arch and transpedal-access approach for revascularization of below-the-knee (BTK) arteries in patients with critical limb ischemia (CLI) after a failed antegrade approach.

MATERIALS AND METHODS

Retrospectively we identified 811 patients who underwent BTK revascularization between 1/2014 and 1/2020. In 115/811 patients (14.2%), antegrade revascularization of at least 1 tibial artery had failed. In 67/115 (58.3%), patients retrograde access to the target vessel was achieved via the femoral access and the plantar-arch (PLANTAR-group); and in 48/115 patients (41.7%) retrograde revascularization was performed by an additional retrograde puncture (TRANSPEDAL-group). Comorbidities, presence of calcification at pedal-plantar-loop/transpedal-access-site, and tibial-target-lesion was recorded. Endpoints were technical success (PLANTAR-group: crossing the plantar-arch; TRANSPEDAL-group: intravascular placement of the pedal access sheath), procedural success [residual stenosis <30% after plain old balloon angioplasty (POBA)], and procedural complications limb salvage and survival. Correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were tested.

RESULTS

Technical success was achieved in 50/67 (75%) patients of the PLANTAR-group and in 39/48 (81%) patients of the TRANSPEDAL-group (p=0.1). Procedural success was obtained in 23/67 (34%) patients of the PLANTAR-group and in 25/48 (52%) patients of the TRANSPEDAL-group (p=0.04). In 14/49 (29%) cases with calcification at the pedal-plantar loop, technical success was not achieved (p=0.04), and in 33/44 (75%) patients with calcification at the tibial-target-lesion, procedural success was not attained (PLANTAR-group) (p=0.026). In the TRANSPEDAL-group, correlations between calcification at access site/tibial-target-lesion and technical/procedural-success were not observed (p=0.2/p=0.4). In the PLANTAR-group, minor complications occurred in 13/67 (19%) and in the TRANSPEDAL-group in 4/48 patients (8%) (p=0.08). Limb salvage at 12 (18) months was 90% (82%) (PLANTAR-group; 95%CI 15.771-18.061) and 84% (76%) (TRANSPEDAL-group; 95%CI 14.475-17.823) (Log-rank p=0.46). Survival at 12 (18) months was 94% (86%) (PLANTAR-group; 95%CI 16.642-18.337) and 85% (77%) (TRANSPEDAL; 95%CI 14.296-17.621) (Log-rank p=0.098).

CONCLUSION

Procedural success was significantly higher using the transpedal-access approach. Calcifications at pedal-plantar loop and target-lesion significantly influenced technical/procedural failure using the plantar-arch approach. No significant difference between both retrograde techniques in terms of feasibility, safety, and limb salvage/survival was found.

Use of drug-eluting stents in patients with critical limb ischemia and infrapopliteal arterial disease: a real-world single-center experience

BACKGROUND

Although no drug-eluting stent (DES) has been approved by the Food and Drug Administration to treat infrapopliteal arterial disease, several industry-sponsored trials have reported the outcomes with the use of paclitaxel or sirolimus DESs. To the best of our knowledge, only one study to date has reported on the use of everolimus DESs for infrapopliteal arterial disease. In the present study, we analyzed the clinical outcomes with everolimus DESs in our real-world, single-center experience.

METHODS

A total of 107 limbs with critical limb threatening ischemia (98 patients; 118 lesions) treated with DESs (Xience; Abbott Vascular, Santa Clara, Calif) were analyzed. The postoperative early outcomes, major adverse limb events (above the ankle limb amputation or major intervention at 1 year), and major adverse events (death, amputation, target lesion thrombosis or reintervention) were analyzed. Kaplan-Meier analysis was used to estimate the primary patency rates (using duplex ultrasound), amputation-free rates, and amputation-free survival rates.

RESULTS

Of the 118 lesions treated, 33% were in the anterior tibial artery, 28% were in the tibioperoneal (TP) artery, 21% were in the posterior tibial artery, 8% were in the peroneal artery, 5% were in the TP/posterior tibial artery, 4% were in the TP artery/PA, and 1% were in the TP/anterior tibial artery. The mean lesion length was 41 mm, and 59% were totally occluded (41% stenotic). The mean follow-up was 18.5 months (range, 1-70 months). The overall postoperative complication rate was 11% (2% major amputations), with 2% mortality. Late symptom improvement of one or more Rutherford category was obtained in 71%. The major adverse events rate at 30 days and 1 year was 12% and 45%, respectively. The major adverse limb events rate at 1 year was 15%. The overall primary patency rate was 42%. The primary patency rate at 1, 2, and 3 years was 57%, 45%, and 33%, respectively. The major amputation-free and overall amputation-free survival rates were 87%, 80%, and 77% and 76%, 65%, and 61% at 1, 2, and 3 years, respectively.

CONCLUSIONS

The clinical outcomes after DES (Xience; Abbott Vascular) for infrapopliteal lesions were somewhat satisfactory at 1 year but inferior to the previously reported outcomes, especially at 3 years. Further data with long-term follow-up are needed.

Stenting versus balloon angioplasty alone in patients with below-the-knee disease: A propensity score-matched analysis

Percutaneous transluminal angioplasty (PTA) is considered an effective treatment in patients with critical limb ischemia (CLI). However, the long-term durability of below-the-knee (BTK) PTA is known to be limited. This study sought to compare the 1-year clinical outcomes following stenting versus balloon angioplasty alone in BTK lesions. This study included 357 consecutive patients (400 limbs, 697 lesions) with BTK lesions who underwent PTA from September 2010 to December 2016. All enrolled patients were treated either by stenting (stent group; 111 limbs of 102 patients) or plain old balloon angioplasty (POBA group; 289 limbs of 255 patients). Stent group includes both primary and provisional stenting. Angiographic outcomes, procedural success, complications, and clinical outcomes were compared between the two groups up to 1 year. After propensity score matching (PSM) analysis, 56 pairs were generated, and the baseline and angiographic characteristics were balanced. The procedural success and complications were similar between the two groups; however, the incidence of procedure-related perforation was higher in the POBA group than in the stenting group [5(11.9%) vs.1 (0.9%), P = 0.009]. Six- to 9-month computed tomography or angiographic follow-up showed similar incidences of binary restenosis, primary patency, and secondary patency. In the 1-year clinical follow-up, there were similar incidences of individual hard endpoints, including mortality, myocardial infarction, limb salvage, and amputation rate, with the exception of target extremity revascularization (TER), which tended to be higher in the stenting group than in the POBA group [21 (20.8%) vs. 11 (10.9%), P = 0.054]. Although there was a trend toward a higher incidence of TER risk in the stenting group, stent implantation, particularly in bail-out stenting seemed to have acceptable 1-year safety and efficacy compared to POBA alone in patients undergoing BTK PTA.

Atherectomy and Drug-Coated Balloon Angioplasty for the Treatment of Long Infrapopliteal Lesions: A Randomized Controlled Trial

[Figure: see text].

[Current Strategy in Endovascular Management for Below-the-Knee Arterial Lesions]

The below-the-knee arterial tree is the thinnest of all the leg vessels and is an important path for blood flow to the foot. Hence, lesions including stenosis, especially obstruction, may lead to critical limb ischemia which represents the most severe clinical manifestation of peripheral arterial disease. It is characterized by the presence of ischemic rest pain, ischemic lesions, or gangrene attributable to the objectively proven arterial occlusive disease. Typically, the atherosclerotic disease process involving the below-the-knee arterial tree is diffuse in the majority of patients. The cornerstone of therapy is vascular reconstruction and limb salvage. Revascularization should be attempted whenever technically possible, without delay, in patients presenting critical limb ischemia and when the clinical status is not hopelessly non-ambulatory. Therefore, endovascular treatment can become the gold standard for the full range of patients including below-the-knee, limiting the clinical role of the classically trained surgeons.

Antegrade and retrograde in-stent tibial artery chronic total occlusion recanalization with double kiss crush (DK crush) stenting of previous stent

Below the knee (BTK) peripheral arterial disease often presents with critical limb ischemia (CLI) clinically with involvement of more than one tibial vessels. Drug eluting stent (DES) technology for treatment of BTK disease has shown promising long-term durable results; however, currently only coronary DESs are available for application in the United States. Although coronary bifurcation stenting techniques are backed by extensive data in literature, there is a scarcity of data for the treatment of tibial bifurcation disease. Bifurcation angles in the tibials are similar to those in the coronaries and therefore the same two stent bifurcation technique can be applied in BTK disease. Double Kiss crush (DK crush) stenting has superior outcomes when compared to provisional or culotte stenting in randomized coronary trials (based on Medina classification). We present a case of BTK CLI with tibial bifurcation chronic total occlusion treated with two stent DK crush technique using coronary DES.

Mid-term outcomes of an everolimus-eluting bioresorbable vascular scaffold in patients with below-the-knee arterial disease: A pooled analysis of individual patient data

Previous studies on everolimus-eluting bioresorbable vascular scaffolds (BVS) have shown promising 1-year primary patency rates in infrapopliteal arteries. Literature from large cohorts on long-term outcomes with the infrapopliteal Absorb BVS (Abbott Vascular) is lacking. The aim of this study is to pool published and unpublished data to provide a more precise estimate of the 24-month outcomes of Absorb BVS for the treatment of infrapopliteal disease. For the pooled analysis, updated original and newly collected data from three cohorts on treatment with the Absorb BVS for de novo infrapopliteal lesions were combined. The primary endpoint was freedom from restenosis. Secondary endpoints were freedom from clinically driven target lesion revascularization (CD-TLR), major amputation and survival. The pooled analysis included a total of 121 patients with 161 lesions, treated with 189 Absorb BVS in 126 limbs. The mean age of the patients was 73 years, 57% had diabetes mellitus, and 75% were classified as Rutherford-Becker class 5 or 6. Of the 161 lesions, 101 (63%) were calcified and 36 (22%) were occlusions. Successful deployment was achieved with all scaffolds. Freedom from restenosis was 91.7% and 86.6% at 12 and 24 months, respectively, and freedom from CD-TLR was 97.2% and 96.6%. Major amputation occurred in 1.6% of the limbs. Overall survival was 85% at 24 months. In conclusion, this pooled analysis represents the largest reported analysis of mid-term results of the Absorb BVS for the management of chronic limb-threatening ischemia. At 24 months, the Absorb BVS was safe with promising clinical outcomes for the treatment of infrapopliteal disease.

Current standards and ethical landscape of engineered tissues-3D bioprinting perspective

Tissue engineering is an evolving multi-disciplinary field with cutting-edge technologies and innovative scientific perceptions that promise functional regeneration of damaged tissues/organs. Tissue engineered medical products (TEMPs) are biomaterial-cell products or a cell-drug combination which is injected, implanted or topically applied in the course of a therapeutic or diagnostic procedure. Current tissue engineering strategies aim at 3D printing/bioprinting that uses cells and polymers to construct living tissues/organs in a layer-by-layer fashion with high 3D precision. However, unlike conventional drugs or therapeutics, TEMPs and 3D bioprinted tissues are novel therapeutics and need different regulatory protocols for clinical trials and commercialization processes. Therefore, it is essential to understand the complexity of raw materials, cellular components, and manufacturing procedures to establish standards that can help to translate these products from bench to bedside. These complexities are reflected in the regulations and standards that are globally in practice to prevent any compromise or undue risks to patients. This review comprehensively describes the current legislations, standards for TEMPs with a special emphasis on 3D bioprinted tissues. Based on these overviews, challenges in the clinical translation of TEMPs & 3D bioprinted tissues/organs along with their ethical concerns and future perspectives are discussed.

GLASS (Global Limb Anatomic Staging System): a critical appraisal

BACKGROUND

THE Global Vascular Guidelines (GVGs) propose a new Global Anatomic Staging System (GLASS) resulting in three stages of complexity for intervention. The aim of this study was to retrospectively classify a large cohort of CLTI patients according to the GLASS, evaluating its distribution in a real-world setting.

METHODS

Retrospective, single center, observational study enrolling all consecutive CLTI patients submitted to infra-inguinal endovascular revascularization in our institution, between June 2014 and September 2019. Patients were categorized according to the GLASS for femoro-popliteal (FP), infra-popliteal (IP) and infra-malleolar grading. FP and IP grades were merged to get the final GLASS stage for each limb.

RESULTS

The study included 1995 CLTI patients who underwent 2850 endovascular procedures in which 6009 arterial lesions were successfully treated. The FP segment was classified as: 1292 (45.3%) grade 0, 475 (16.6%) grade 1, 159 (5.6%) grade 2, 209 (7.4%) grade 3, and 715 (25.1%) grade 4. The IP segment was classified as: 1529 (53.6%) grade 0, 183 (6.4%) grade 1, 80 (2.8%) grade 2, 207 (7.3%) grade 3, and 851 (29.9%) grade 4. The combination of FP and IP grading led to GLASS stages: 922 (32.3%) stage 1, 375 (13.2%) stage 2, 1472 (51.6%) stage 3.

CONCLUSIONS

The distribution of the FP, IP and final GLASS grading was mainly grouped at the two extremes, letting the intermediate grades rather scarce. The majority of patients present with an absent or severely diseased pedal arch, stressing the need to incorporate infra-malleolar disease into the GLASS.

Outcomes of endovascular treatment for infrapopliteal peripheral artery disease based on the updated TASC II classification

We retrospectively analyzed all endovascular procedures of infrapopliteal arterial lesions (n = 383) performed in 270 patients at our institution between December 2008 and January 2018. The overall technical success rate was 97% and yielded 98% for stenoses (n = 214) and 95% for occlusions (n = 169). Trans-Atlantic Inter-Society Consensus (TASC II) classification had no impact on success rates (TASC A + B vs C + D; 96.5% vs 96.9%, p = 0.837). Freedom from clinically driven target lesion revascularization (TLR) after 6 and 12 months was 88.3% and 77.2%. TLR was comparable for TASC A to C lesions and no difference was observed comparing groups of moderately complex TASC A/B lesions and more complex TASC C/D lesions (TASC A + B vs C + D; 78.5% vs 74.2%, p = 0.457). Freedom from TLR was significantly lower in very complex TASC D lesions (TASC A + B + C vs D; 79.7% vs 42.5%, p < 0.001). Multivariate analysis identified TASC D lesions (hazard ratio D/A: 1.5; overall p = 0.002), Fontaine class III and IV (hazard ratio III or IV/IIa or IIb: 2.4; p = 0.041), and occlusive lesions (hazard ratio occlusion/stenosis: 2.4; p = 0.026) as predictors for TLR. In conclusion, endovascular therapy for infrapopliteal artery disease was safe and accompanied with a promising long-term outcome.

Six-month pivotal results of tack optimized balloon angioplasty using the Tack Endovascular System in below-the-knee arteries

OBJECTIVE

No vascular implant is commercially available in the United States to treat post-angioplasty dissections in below-the-knee (BTK) arteries. The Tack Endovascular System (Intact Vascular, Wayne, Pa) is purpose-built to repair postpercutaneous transluminal angioplasty (PTA) BTK dissections. A trial was conducted to investigate the safety and efficacy of the first-of-a-kind implantable BTK device to treat post-PTA dissections in the setting of critical limb ischemia.

METHODS

The present prospective, single-arm, multicenter study evaluated the Tack Endovascular System for treating post-PTA dissections in the mid/distal popliteal, tibial, and peroneal arteries. The primary safety endpoint was major adverse limb events (MALE) plus perioperative death (POD), assessed at 30 days after the index procedure. The primary efficacy endpoint was a composite of MALE at 6 months and POD. The unpowered secondary endpoint was primary patency at 6 months. With no available on-label comparator, the primary endpoints of the present trial were determined using objective performance goals from a systematic literature search. The secondary endpoints included Tacked segment patency and target limb salvage at 6 months. The 6-month results are reported.

RESULTS

Of the 233 patients enrolled, 117 (50.2%) had Rutherford class 5 and 78 (33.5%) had Rutherford class 4. A total of 341 post-PTA dissections were treated. Each patient received at least one Tack implant, and 100% of the dissections resolved according to the angiographic core laboratory findings. The primary safety and efficacy endpoints were both met. The rate of MALE plus POD at 30 days was 1.3% (3 of 228) and freedom from MALE at 6 months plus POD at 30 days was 95.6% (196 of 205). The 6-month Tacked segment patency was 82.1% (247 of 301) and target limb salvage was 98.5% (202 of 205). The Kaplan-Meier freedom from clinically driven target lesion revascularization and amputation-free survival at 6 months was 92.0% and 95.7%, respectively. Rutherford improvement was reported in 79.4% (158 of 199). Most (90 of 122; 73.8%) preexisting wounds had healed or were improving.

CONCLUSIONS

The Tack Endovascular System is safe and effective for treating post-PTA BTK dissections through 6 months, with favorable rates of MALE plus POD, patency, clinically driven target lesion revascularization, limb salvage, and wound healing.

Two-year follow-up of bioresorbable vascular scaffolds in severe infra-popliteal arterial disease

OBJECTIVES

To assess the safety, efficacy, and durability of the Absorb bioresorbable vascular scaffold in predominantly complex, infra-popliteal lesions for the management of chronic limb ischemia at two-year clinical follow-up. Bioresorbable vascular scaffold are biodegradable scaffolds that provide short-term vascular support before undergoing intravascular degradation. A recent trial reported excellent 36-month vessel patency rates in simple infrapopliteal arterial lesions treated with Absorb bioresorbable vascular scaffold.

METHODS

This single-center, retrospective study evaluated the use of the Absorb bioresorbable vascular scaffold (everolimus impregnated poly-L-lactic scaffold) in patients with infra-popliteal peripheral arterial disease (PAD) with respect to safety (thrombosis and TIMI bleeding), technical success, and freedom from clinically driven target vessel failure at 24 months.

RESULTS

31 patients (51.6% male) with a median age of 67 years with predominantly advanced infra-popliteal disease were treated with 49 bioresorbable vascular scaffold in 41 vessels. The mean stenosis was 94% (80-100), with 49% of lesions being chronic thrombotic occlusions. No scaffold thrombosis or peri-procedural bleeding was observed. Procedural success was achieved in all patients; 93.5% of patients experienced freedom from clinically driven target vessel failure at 24 months, driven by one revascularization and one amputation. Primary patency was 96.7% at 12 months and 87.1% at 24 months. All patients were alive at 12 and 24 months.

CONCLUSIONS

At 24 months, our study found that patients with predominantly advanced infra-popliteal PAD who were treated with Absorb bioresorbable vascular scaffold reported improved clinical status and a low and durable rate of clinically driven target vessel failure extending out to 24 months.

Rationale and design for the study Apixaban versus ClopidoGRel on a background of aspirin in patient undergoing InfraPoPliteal angioplasty for critical limb ischemia: AGRIPPA trial

BACKGROUND

New antithrombotic strategies that reduce primary thrombosis and restenosis might improve vascular outcomes in patients with peripheral artery disease (PAD) undergoing arterial angioplasty. The study objective is to evaluate the potential benefit of apixaban plus aspirin compared with standard of care dual antiplatelet therapy (DAPT) in reducing thrombotic restenosis and artery re-occlusion in patients undergoing endovascular infrapopliteal revascularization.

STUDY DESIGN

This multicenter, parallel-group, prospective, randomized, open-label, blinded-endpoint adjudication, proof-of-concept, exploratory trial aims to randomize 200 patients 72 hours after successful infrapopliteal angioplasty for critical limb ischemia (CLI). Patients will be randomly assigned in a 1:1 ratio to receive oral apixaban (2.5 mg twice daily) plus aspirin (100 mg once daily) for 12 months or clopidogrel (75 mg daily) for at least 3 months on a background of aspirin (100 mg once daily) for 12 months. The primary endpoint is the composite of target lesion revascularization (TLR), major amputation, or restenosis/occlusion (RAS) in addition to major adverse cardiovascular events - MACE (myocardial infarction, stroke or cardiovascular death) at 12 months. The primary safety endpoint is the composite of major bleeding or clinically relevant non-major bleeding at 12 months.

SUMMARY

This study will evaluate the efficacy and safety of apixaban 2.5 mg twice daily plus aspirin compared with DAPT (clopidogrel plus aspirin) in patients with CLI undergoing endovascular infrapopliteal revascularization and might prove the concept of an alternative antithrombotic regimen for these patients to be tested in a future large randomized clinical trial.

10-Year Paclitaxel Dose-Related Outcomes of Drug-Eluting Stents Treated Below the Knee in Patients with Chronic Limb-Threatening Ischemia (The PADI Trial)

Purpose

Recently, two meta-analyses concluded that there appears to be an increased risk of long-term mortality of paclitaxel-coated balloons and stents in the superficial femoral and popliteal artery, and paclitaxel-coated balloons below the knee. In this post hoc study of the PADI Trial, we investigated the long-term safety of first-generation paclitaxel-coated drug-eluting stents (DES) below the knee and the dose–mortality relationships of paclitaxel in patients with chronic limb-threatening ischemia (CLI).

Materials and Methods

The PADI Trial compared paclitaxel-coated DES with percutaneous transluminal angioplasty with bail-out bare-metal stents (PTA ± BMS) in patients with CLI treated below the knee. Follow-up was extended to 10 years after the first inclusion, and survival analyses were performed. In addition, dose-related mortality and dose per patient weight-related mortality relations were examined.

Results

A total of 140 limbs in 137 patients were included in the PADI Trial. Ten years after the first inclusion, 109/137 (79.6%) patients had died. There was no significant difference between mortality in the DES group compared with the PTA ± BMS group (Log-rank p value = 0.12). No specific dose-related mortality (HR 1.00, 95% CI 0.99–1.00, p = 0.99) or dose per weight mortality (HR 1.05, 95% CI 0.93–1.18, p = 0.46) relationships were identified in the Cox-proportional Hazard models or by Kaplan–Meier survival analyses.

Conclusions

There is a poor 10-year survival in both paclitaxel-coated DES and PTA ± BMS in patients with CLI treated below the knee. No dose-related adverse effects of paclitaxel-coated DES were observed in our study of patients with CLI treated below the knee.

Level of Evidence

The PADI Trial: level 1, randomized clinical trial

Electronic supplementary material

The online version of this article (10.1007/s00270-020-02602-6) contains supplementary material, which is available to authorized users.

Mortality in patients undergoing revascularization with paclitaxel eluting devices for infrainguinal peripheral artery disease: Insights from a network meta-analysis of randomized trials

OBJECTIVES

We aimed to evaluate whether paclitaxel eluting devices increased the risk of death in patients undergoing revascularization for infrainguinal peripheral artery disease using network meta-analyses.

METHODS

PUBMED and EMBASE were searched through April 2020 for randomized trials in patients with infrainguinal peripheral artery disease who underwent revascularization with or without a paclitaxel eluting device (balloon/stent). Short-term mortality defined as death at 6-12 months, and long-term mortality defined as death at >12 months after revascularization.

RESULTS

Our search identified 57 eligible randomized controlled studies enrolling a total of 9,362 patients comparing seven revascularization strategies (balloon angioplasty vs. bare metal stent vs. covered stent vs. paclitaxel eluting stent vs. other drug eluting stent vs. paclitaxel-coated balloon vs. bypass surgery). Overall, paclitaxel eluting stent and paclitaxel-coated balloons did not increase short-term mortality (eg, vs. balloon angioplasty: paclitaxel-coated balloon OR [95% CI] 1.21 [0.88-1.66], p = .24; paclitaxel eluting stent OR [95%CI] 1.01 [0.63-1.63], p = .97, respectively). In addition, paclitaxel eluting stent did not show significant increase in long-term mortality (eg, vs. balloon angioplasty: OR [95%CI] 1.06 [0.70-1.59], p = .79). However, paclitaxel-coated balloon showed significant increase in long-term mortality compared to balloon angioplasty and bypass (vs. balloon angioplasty: OR [95% CI] 1.48 [1.06-2.07], p = .021; vs. bypass: OR [95%CI] 1.73 [1.05-2.84], p = .031, respectively).

CONCLUSIONS

In this meta-analysis of randomized trials, there was no significant increase in mortality with paclitaxel eluting stent, but there was increased risk of long-term mortality in paclitaxel-coated balloon for the treatment of infrainguinal peripheral artery disease.