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.

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.).

Efficacy and Safety of Absorb Everolimus-Eluting Bioresorbable Vascular Scaffold in Peripheral Artery Disease: A Single-Arm Meta-Analysis

PURPOSE

This study aimed to evaluate the benefits and risks of patients with peripheral artery disease (PAD) treated with Absorb everolimus-eluting bioresorbable vascular scaffold (BVS) by analyzing all the published studies on the clinical characteristics of patients with PAD.

MATERIALS AND METHODS

PubMed, Embase, and the Cochrane Library were searched for relevant studies. Efficacy, safety, and basic characteristics were analyzed.

RESULTS

Four studies were included in meta-analysis, including a total number of 155 patients with PAD. The pooled overall primary patency, freedom from target lesion revascularization (TLR), symptom resolution, and wound healing were 90%, 96%, 94%, and 86%, respectively. The pooled perioperative complication and all-cause mortality were 4% and 9%, respectively. Preoperative total occlusion was detected in 43 of 192 lesions (22%). The mean lesion length was 27.26 mm. In terms of comorbidities, the pooled percentage of hypertension, hyperlipidemia, diabetes mellitus, coronary artery disease, chronic kidney disease history, and smoking were 65%, 74%, 49%, 43%, 20%, and 57%, respectively.

CONCLUSION

Among these studies, hypertension, hyperlipidemia, and diabetes mellitus were the most common comorbidities in patients with PAD. The Absorb everolimus-eluting BVS was safe and showed the favorable clinical outcomes in both patency and TLR, especially in infrapopliteal disease with heavy calcification. The conclusions of this meta-analysis still needed to be verified by more relevant studies with more careful design, more rigorous execution, and larger sample size.

Acute lower extremity ischaemia after surgical interventricular communication closure in a newborn

We report a 5-month-old infant who developed an unexpected acute ischaemia of the right lower limb following a surgical perimembranous interventricular communication closure. This rare case of ischaemia was due to an occlusive right common iliac artery dissection. It was early managed by angioplasty with two ABSORB® bioresorbable stents, resulted in complete revascularisation of the right leg.

Current perspectives on bioresorbable scaffolds in coronary intervention and other fields

Introduction: The first-generation bioresorbable scaffolds (BRSs) had a large strut profile to compensate for the insufficient radial strength of bioresorbable polymer materials, resulting in higher scaffold thrombosis rates than conventional drug-eluting stents. To improve the clinical safety and efficacy, the new generation BRSs have been improved by optimal structure design, post-processing of bioresorbable polymer materials, or altering bioresorbable metallic alloys.Areas covered: This review summarizes the lessons learned from the first-generation BRS, updates the clinical outcomes of trials evaluating ABSORB bioresorbable vascular scaffold at long-term and bioresorbable metallic alloy-based devices, and examines recent outcomes of BRS treated in STEMI patients. This review also provides an overview of the current clinical data of seven BRSs manufactured in Asia, and of the BRSs extended application in other clinical arenas.Expert opinion: Drawbacks of the first-generation BRSs need to be addressed by the next generation of these stents with novel materials and technologies. Clinical research, including randomized controlled trials, are required to further evaluate BRSs application in coronary artery disease. The encouraging results of BRSs innovation applied in the peripheral arteries and gastrointestinal tracts support other potential clinical applications of BRS technology.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

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.

A systematic review and meta-analysis of bioresorbable vascular scaffolds for below-the-knee arterial disease

INTRODUCTION

Different types of bioresorbable vascular scaffolds (BVSs) have been developed and used in below-the-knee (BTK) arterial diseases. This is the first study reviewing and analyzing the literature on BVS treatment for BTK arterial disease.

EVIDENCE ACQUISITION

MEDLINE, Embase, and Cochrane were searched for studies published until October 21, 2019. The search, study selection, quality assessment, and data extraction were performed by 2 authors independently. Articles that studied the treatment of BTK arterial disease by using BVSs were eligible. Exclusion criteria were studies with a variant design (e.g. case reports <5 patients), non-BTK indications for BVS use, and nonhuman studies. Primary endpoint was 12-month primary patency. Secondary endpoints were 12-month freedom from clinically driven target lesion revascularization (CD-TLR), limb salvage, survival, and amputation-free survival (AFS). Study quality was assessed by the Methodological Index for Non-randomized Studies score.

EVIDENCE SYNTHESIS

Five studies representing 155 patients with 160 treated limbs met the inclusion criteria. Pooled 12-month primary patency per limb was 90% (143/160; 95% confidence interval [CI]: 0.84-0.95), freedom from CD-TLR 96% (124/130; 95% CI: 0.91-0.99), limb salvage rate 97% (156/160; 95% CI: 0.94-1.00), survival rate 90% (112/125; 95% CI: 0.82-0.96), and AFS rate 89% (110/125; 95% CI: 0.81-0.94). Subgroup analyses of included Absorb BVS studies showed similar results. All studies were assessed as moderate quality.

CONCLUSIONS

This meta-analysis of case series showed good 12-month patency and clinical results with BVSs for BTK arterial disease, even in patients with multimorbidity and short but complex lesions. These results encourage a revival of this scaffold.