PROMISE international; a clinical post marketing trial investigating the percutaneous deep vein arterialization (LimFlow) in the treatment of no-option chronic limb ischemia patient

Short-Term Outcomes and Efficacy of Percutaneous Deep Vein Arterialization for No-Option Critical Limb Ischemia: A Systematic Review and Meta-Analysis

BACKGROUND

Percutaneous deep vein arterialization (pDVA) is considered a treatment modality in patients with no-option critical limb ischemia. However, there is still a paucity of evidence regarding its safety and efficacy.

DATA SOURCES

MEDLINE (via PubMed), Embase and Web of Science databases as well as the CENTRAL registry up to the end of June 2023.

METHODS

This review adhered to the PRISMA guidelines (PROSPERO registration no. CRD42023445171). The risk of bias was assessed using the methodological index for non-randomized studies (MINORS). Primary endpoints included technical success, overall survival and limb salvage during the follow-up. Amputation-free survival at 30 days, 6 months and 1 year as well as complete wound healing, major adverse limb events and reintervention were investigated as secondary outcomes.

RESULTS

Five observational studies, comprising 208 patients (142 Rutherford class 5/77 Rutherford class 6), were included. MINORS revealed a low risk of bias. The meta-analysis reached a pooled technical success rate of 96.2% (95% CI: 91.5-98.4), an overall survival of 82.8% (95% CI: 70.5-95.2) and a limb salvage rate of 77.2% (95% CI: 65.2-89.1) during the follow-up. The amputation-free survival at 30 days, 6 months and 1 year was 87.8%, 68.7% and 65.6%, respectively. Furthermore, pDVA resulted in a complete wound healing rate of 53.4% (95% CI: 30.3-76.5). The pooled reintervention rate was as high as 46.7% (37.1-56.3%).

CONCLUSIONS

PDVA seems a feasible bail-out strategy for patients with no option for routine treatment of CLTI. However, due to the small number of studies, the strength of the evidence is low.

Improving Bioactive Characteristics of Small Diameter Polytetrafluoroethylene Stent Grafts by Electrospinning: A Comparative Hemocompatibility Study

Polytetrafluoroethylene (PTFE) is a commonly used biomaterial for the manufacturing of vascular grafts and several strategies, such as coatings, have been explored to improve the hemocompatibility of small-diameter prostheses. In this study, the hemocompatibility properties of novel stent grafts covered with electrospun PTFE (LimFlow Gen-1 and LimFlow Gen-2) were compared with uncoated and heparin-coated PTFE grafts (Gore Viabahn®) using fresh human blood in a Chandler closed-loop system. After 60 min of incubation, the blood samples were examined hematologically and activation of coagulation, platelets, and the complement system were analyzed. In addition, the adsorbed fibrinogen on the stent grafts was measured and the thrombogenicity was assessed by SEM. Significantly lower adsorption of fibrinogen was measured on the surface of heparin-coated Viabahn than on the surface of the uncoated Viabahn. Furthermore, LimFlow Gen-1 stent grafts showed lower fibrinogen adsorption than the uncoated Viabahn®, and the LimFlow Gen-2 stent grafts showed comparable fibrinogen adsorption as the heparin-coated Viabahn®. SEM analysis revealed no sign of thrombus formation on any of the stent surfaces. LimFlow Gen-2 stent grafts covered with electrospun PTFE exhibited bioactive characteristics and revealed improved hemocompatibility in terms of reduced adhesion of fibrinogen, activation of platelets, and coagulation (assessed by β-TG and TAT levels) similar to heparin-coated ePTFE prostheses. Thus, this study demonstrated improved hemocompatibility of electrospun PTFE. The next step is to conduct in vivo studies to confirm whether electrospinning-induced changes to the PTFE surface can reduce the risk of thrombus formation and provide clinical benefits.

Eligibility of Patients with Chronic Limb Threatening Ischemia for Deep Venous Arterialization

OBJECTIVES

Percutaneous deep venous arterialization (pDVA) has emerged as a new modality for limb salvage in patients with chronic limb threatening ischemia (CLTI) and no standard option for revascularization. The proportion of patients facing major amputation that are eligible for this technology remains unknown. This study aims to provide a real-life estimate of patient eligibility for pDVA to reduce major amputations.

METHODS

Electronic medical records of 100 consecutive patients with peripheral arterial disease (PAD) who underwent major amputation of 106 limbs were reviewed. Angiograms performed ≤6 months before amputation were assessed by two vascular surgeons. Disease severity was categorized using the Global Limb Anatomic Staging System and patients were classified as ideal, possible, or not candidates for pDVA. Ideal candidates had ≥1 patent tibial artery, no target in the foot, and no proximal disease. Possible candidates had ≥1 patent tibial artery with PAD, no target in the foot, and proximal disease amenable to endovascular therapy. Patients were not eligible if there was no patent tibial artery, extensive PAD, or an arterial target in the foot for bypass.

RESULTS

Of 106 limbs reviewed, 35 (33%) did not undergo angiography ≤6 months before amputation because of infection (n=14), advanced tissue loss (n=10), failed revascularizations (n=8), advanced limb ischemia (n=2), and refusing revascularization (n=1). Thus, 69 lower extremity angiograms (2 incomplete excluded) in 68 patients were analyzed. 15 patients with 16 limbs (23.2%) were identified as candidates for pDVA (ideal=7, possible=9). There were no differences in demographics between the two groups, but candidates for pDVA were less likely to have hyperlipidemia and congestive heart failure than those who were not candidates. pDVA candidates underwent significantly fewer interventions prior to major amputation compared to patients who were not candidates (1.50 ± 0.73 vs 2.61 ± 2.57, p=0.007). Angiographically, patients who were pDVA candidates had significantly higher Inframalleolar GLASS grades (1.81 ± 0.40 vs 0.86 ± 0.41, p<0.0001) but lower Femoropopliteal Glass grades (0.73 ± 1.10 vs 2.43 ± 1.71, p<0.0001) than patients who were not candidates. There was no significant difference in GLASS stage between these two groups (p=0.368). After mean follow-up of 48 months, there was no difference in mortality between both groups (40% vs 32.1%, p=0.567).

CONCLUSION

Among patients considered for revascularization, 23.2% had favorable angiography and 14.7% could have benefited for pDVA as a new therapeutic modality for limb salvage. 33% of major amputations were performed for clinically-deemed unsalvageable CLTI.

A systematic review of patient-reported outcome measures patients with chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) causes significant morbidity with profound negative effects on health-related quality of life. As the prevalence of peripheral artery disease and diabetes continue to rise in our aging population, the public health impact of CLTI has escalated. Patient-reported outcome measures (PROMs) have become common and important measures for clinical evaluation in both clinical care and research. PROMs are important for the measurement of clinical effectiveness and cost effectiveness and for shared decision-making on treatment options. However, the PROMs used to describe the experience of patients with CLTI are heterogeneous, incomplete, and lack specific applicability to the underlying disease processes and diverse populations. For example, certain PROMs exist for patients with extremity wounds, and other PROMs exist for patients with pain, and still others exist for patients with vascular disease. Despite this multiplicity of tools, no single PROM encompasses all of the components necessary to describe the experiences of patients with CLTI. This significant unmet need is evident from both published reports and contemporary large-scale clinical trials in the field. In this systematic review, we review the current use of PROMs for patients with CLTI in clinical practice and in research trials and highlight the gaps that need to be addressed to develop a unifying PROM instrument for CLTI.

Early and eighteen month clinical outcomes of first UK case of percutaneous deep vein arterialisation (pDVA) to treat "no option" chronic limb-threatening ischemia using the LimFlow system

Background

Chronic limb-threatening ischaemia (CLTI) in cases where there are no further standard treatment options for limb salvage represents the most advanced stage of peripheral arterial disease. For these “no-option” CLTI patients, an experimental treatment of foot vein arterialisation (FVA) was first described in 1912, however, it was never widely adopted as outcomes varied significantly most likely due to the complexity of the surgical intervention and lack of standardisation. In recent years there have been significant developments in performing FVA fully percutaneously and standardising the procedure with the introduction of specific indications for patient selection, a dedicated set of devices and structured follow up. This case represents the first UK use of the dedicated LimFlow System as a standardised procedure to perform percutaneous deep vein arterialisation (pDVA) in a “no option” CLTI patient according to the latest treatment recommendations in the literature, with outcomes out to 18 months post-procedure.

Case presentation

We present the case of a 78 year old male diabetic patient with a history of contralateral below knee amputation who presented with ischaemic rest pain and dry gangrene involving his left heel and first and second toes. Following review by the lower limb multi-disciplinary team at our institution, the patient was deemed to have no surgical or endovascular treatment options, apart from major amputation, as there was no suitable target for either angioplasty or bypass. He was therefore referred as a candidate for percutaneous deep vein arterialisation (pDVA) with the LimFlow System (LimFlow SA, France). After screening of the patient according to the indications for use, the pDVA procedure was successfully performed resulting in complete resolution of ischaemic rest pain immediately following the procedure, and adequate revascularisation of the foot. Following the index procedure, the subject went on to have minor amputation of the first, second and third toes 2 months post initial procedure with further secondary angioplasty procedures to optimise the flow throughout the arterialised circuit up to 4 months after the initial procedure. He underwent elective completion transmetatarsal amputation at 13 months post index procedure. The surgical wounds post minor amputation and the heel wound showed continued healing, especially after secondary optimisation of the pDVA outflow, with tissue epithelialisation by 6 months and complete healing by 18 months after the index procedure.

Conclusions

This case report demonstrates the clinical outcomes of a technically-successful standardised pDVA procedure with the LimFlow system including both limb salvage and wound healing at 18 months. It also highlights the importance of close clinical and radiological surveillance post-index procedure and the requirement for re-interventions to optimise wound healing.

Repeat BTK revascularization: when, how and what are the results?

INTRODUCTION

Owing to the ageing of the population and rising rates of diabetes, more patients suffering from chronic limb threatening ischemia (CLTI) need revascularization for often complex, multilevel peripheral arterial occlusive disease. Below the knee (BTK) lesions are common in CLTI and short-term outcomes of BTK endovascular revascularizations have improved substantially over the last decade as a consequence of improved techniques and dedicated low profile devices.

EVIDENCE ACQUISITION

The manuscript summarized the information identified through a limited literature review conducted on key resources including MEDLINE and EMBASE databases as well as conference proceedings. The keywords were "angioplasty," "endovascular intervention," "infrapopliteal," "tibial arteries" and "below the knee." The search was limited to contemporary English-language documents published between 2000 and 2020.

EVIDENCE SYNTHESIS

Rates of re-stenosis and re-occlusion are high after infrapopliteal interventions limiting long-term success and necessitating frequent repeat procedures.

CONCLUSIONS

In this article we aimed to summarize current knowledge regarding the need, options and outcome of repeat BTK interventions through a limited literature review and presentation of own data.

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

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