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 The aim of this study is to pool published and unpublished data to provide a more precise estimate of the 24-month outcomes of Absorb BVS for the treatment of infrapopliteal disease.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

Vasculitis resulting from a superficial femoral artery angioplasty with a paclitaxel-eluting balloon

Drug-eluting balloons (DEBs) coated with the antiproliferative agent paclitaxel may improve primary patency by reducing recurrent luminal stenosis. A proportion of the active drug and excipient coating are known to embolize distally, but until now, there have been no reports of adverse events resulting from their use. We report an unusual case of a painful nodular, biopsy specimen-proven vasculitic rash that afflicted the ipsilateral lower limb of a patient after superficial femoral artery treatment with a DEB. This adverse event may have implications for the use of DEB in this and other vascular territories

Update on paclitaxel for femoral-popliteal occlusive disease in the 15&nbsp;months following a summary level meta-analysis demonstrated increased risk of late mortality and dose response to paclitaxel

BackgroundPeripheral vascular devices (stents and balloons) coated with paclitaxel were developed to address suboptimal outcomes associated with percutaneous revascularization procedures of the femoral-popliteal arteries. In randomized controlled trials (RCT), paclitaxel-coated devices (PCD) provided increased long-term patency and a decreased need for repeat revascularization procedures compared with uncoated devices. This finding resulted in the adoption of their use for endovascular lower extremity revascularization procedures. However, in late 2018 a study-level meta-analysis showed increased all-cause mortality at 2&nbsp;years or more after the procedure in patients treated with PCDs. This review examines the subsequent data evaluation following the publication of the meta-analysis.MethodsWe review the published responses of physicians, regulatory agencies, and patient advocates during 15-month period after the meta-analysis. We present the additional data gathered from RCTs that comprised the meta-analysis and safety outcomes from large insurance databases in both the United States and Europe.ResultsImmediately after the publication of the meta-analysis, concern for patient safety resulted in less PCD use, the suspension of large RCTs evaluating their use, and the publication of a letter from the U.S. Food and Drug Administration informing physicians that there was uncertainty in the benefit-risk profile of these devices for indicated patients and that the potential risk should be assessed before the use of PCDs. Review of the meta-analysis found that a mortality signal was present, but criticisms included that the evaluation was performed on study-level, not patient-level data, and the studies in the analysis were heterogenous in device type, paclitaxel doses, and patient characteristics. Further, the studies were not designed to be pooled nor were they powered for evaluating long-term safety. Clinical characteristics associated with a drug effect or causal relationship were also absent. Specifically, there was no dose response, no clustering of causes of death, and a lack of signal consistency across geographic regions. As more long-term data became available in the RCTs the strength of the mortality signal diminished and analysis of real-world use in large insurance databases, showed that there was no significant increase in all-cause mortality associated with PCD use.ConclusionsThe available data do not provide definitive proof for increased mortality with PCD use. A key observation is that trial design improvements will be necessary to better evaluate the risk-benefit profile of PCDs

A numerical investigation of a stented arteriovenous fistula

An arteriovenous fistula (AVF) is a surgically created vasculaturefor end stage renal disease patients who require haemodialysis.The AVF is susceptible to high failure rates mainly dueto the onset of intimal hyperplasia which is known to be linkedto disturbed hemodynamics. One method adopted to treat thiscondition is to implant a flexible stent in the diseased region.In the present study, a silicone model of a patient-specific AVFwas implanted with the Supera stent and subsequently scannedusing a micro-CT. Using the segmentation of the high resolutionscan, the AVF geometry with the stent detail was recreated andReynolds averaged Navier Stokes simulations were conductedwith pulsatile inlet flows of Reynolds numbers ranging from345 to 730. Subsequently, two low velocity zones which translatedto low wall shear stress zones were identified in the AVF.Other flow behaviour such as twisting flow from the high flowzones to low flow zones were also apparent. This study formsthe basis to extend into large eddy simulations to detail the flowdisturbances in the AVF to better understand the impact of thestent on the AVF health

The investigation of novel technology and technique in the treatment of vascular disease

Cardiovascular disease takes more human life than any other disease process. The vascular specialist fights a daily battle to limit the progression of atherosclerosis and replenish the circulation when it is compromised. Increasingly reliant on technological advances, the specialty is responsible for the evaluation of new devices and techniques through scientific method. This thesis represents a body of work which addresses several advances within the realm of vascular disease.In the first experimental portion a large animal model was established to evaluate a novel, nitinol, anastomotic device, the U-clip. Arteriovenous fistulae were created to compare the local cellular response around it and the conventional suture material. A distinct advantage was observed for the new technology with less intimal hyperplasia, necrosis and proliferating cells at earlier time points. The second experimental portion saw a focus on carotid artery stenting (CAS), a percutaneous method of revascularisation which utilises nitinol for both the carotid stent and the cerebral protection device (CPD). In a comprehensive histological and biomarker analysis the debris collected in the distal-filter CPD was found to contain more calcified tissue and fewer foam cells in symptomatic patients compared to asymptomatic ones. It also demonstrated a greater proportion of inflammatory cytokines, macrophage specific proteins and matrix metelloproteinase (MMP)-9, a gelatinase known to incite histological features of plaque vulnerability. In a second study a new technique to perform CAS guided by extra-vascular ultrasound was compared with standard CAS (fluoroscopy/angiography). This demonstrated significantly less contrast use and fewer direct cerebral injections whilst maintaining equivalent safety and efficacy. A corrosion-resistance analysis of nitinol stents used throughout the human body was performed to compare five stents used in clinical practice. It found a degree of difference in the corrosion-resistance properties of those five devices and demonstrated that corrosion in isolation may lead to stent fracture. Finally, the evolution of clinical practice in the treatment of critical lower limb ischaemia was evaluated in a single-centre experience. A shifting paradigm toward an endovascular-first strategy resulted in fewer major amputations and considerably less reliance on hospital inpatient resources compared to the open-surgery-first approach of a bygone era