Trends in Lower Extremity Artery Disease Repair Incidence, Comorbidity, and Mortality: A Danish Nationwide Cohort Study, 1996-2018

Background

The prevalence of occlusive lower extremity artery disease (LEAD) is rising worldwide while European epidemiology data are scarce. We report incidence and mortality of LEAD repair in Denmark from 1996 through 2018, stratified on open aorto-iliac, open peripheral, and endovascular repair.

Methods

A nationwide cohort study of prospective data from population-based Danish registers covering 1996 to 2018. Comorbidity was assessed by Charlson's Comorbidity Index (CCI). Incidence rate (IR) ratios and mortality rate ratios (MRR) were estimated by multivariable Poisson and Cox regression, respectively.

Results

We identified 41,438 unique patients undergoing 46,236 incident first-time LEAD repairs by either aorto-iliac- (n=5213), peripheral surgery (n=18,665) or percutaneous transluminal angioplasty (PTA, n=22,358). From 1996 to 2018, the age- and sex-standardized IR for primary revascularization declined from 71.8 to 50.2 per 100,000 person-years (IRR, 0.70; 95% CI, 0.66-0.75). Following a 2.5-fold IR increase of PTA from 1996 to 2010, all three repair techniques showed a declining trend after 2010. The declining IR was driven by decreasing LEAD repair due to claudication, and by persons aged below 80 years, while the IR increased in persons aged above 80 years (p interaction<0.001). LEAD repair was more frequent in men (IRRfemale vs male, 0.78; 95% CI, 0.77-0.80), which was consistent over calendar time (p interaction=0.41). Crude mortality decreased following open/surgical repair, and increased following PTA, but all three techniques trended towards lower adjusted mortality comparing the start and the end of the study period (MRRaorto-iliac, 0.71; 95% CI, 0.54-0.93 vs MRRperipheral, 0.76; 95% CI, 0.69-0.83 vs MRRPTA, 0.96; 95% CI, 0.86-1.07). Increasing age and CCI, male sex, smoking, and care dependency associated with increased mortality.

Conclusion

The incidence rate of LEAD repair decreased in Denmark from 1996 to 2018, especially in persons younger than 80 years, and primarily due to reduced revascularization for claudication. Adjusted mortality rates decreased following open surgery, but seemed unaltered following PTA.

High Mortality in Patients With an Ischemic Foot Ulcer Following Revascularization

Critical limb ischemia (CLI) is the advanced stage of peripheral arterial disease, which impairs blood flow to the extremities due to occlusion of arteries, in which patients suffer from ischemic pain at rest and gangrene or ulcers. It is frequently accompanied by major adverse cardiac events, resulting in exceedingly high mortality from a cardiac or cerebrovascular event in this population. Although there have been considerable amounts of novel and costly revascularization and wound dressing technology, mortality is still high. Therefore, the risk factors for such high mortality need to be addressed. This review aimed to summarize the potential risk factors for mortality in patients with CLI of the lower extremities. There are several such risk factors, including modifiable and nonmodifiable risk factors. This review further discusses some highlighted major modified risk factors, including renal failure, cardiovascular, and diabetes. The strategy of regular surveillance and modification of such risk factors in any patients with CLI should be developed.

An Endovascular- Versus a Surgery-First Revascularization Strategy for Chronic Limb-Threatening Ischemia: A Meta-Analysis of Randomized Controlled Trials

Timely revascularization is essential for limb salvage and to reduce mortality in patients with chronic limb-threatening ischemia (CLTI). In patients who are candidates for endovascular therapy and surgical bypass, the optimal revascularization strategy remains uncertain. Recently published randomized controlled trials (RCTs) have presented conflicting results. We conducted a trial-level meta-analysis to compare the outcomes between endovascular-first and surgery-first strategies for revascularization. PubMed, Web of Science, and the Cochrane Library were searched to identify RCTs comparing the outcomes of endovascular-first versus surgery-first strategies for revascularization in patients with CLTI. Data were pooled for major outcomes and their aggregate risk ratios (RRs) with 95% confidence intervals were calculated using a random-effects model. Kaplan-Meier curves for amputation-free survival and overall survival time were plotted using the pooled aggregated data from published curves, with their corresponding hazard ratios (HRs) and 95% confidence intervals reported for up to 5 years of follow-up. A total of 3 RCTs with 2,627 patients (1,312 endovascular-first and 1,315 surgery-first) were included in the meta-analysis. Of these, 1,864 patients (70.9%) were men and 347 (13.2%) were older than 80 years. Comparing the endovascular-first and surgery-first approaches, there was no significant difference in the overall (HR 0.92 [0.83 to 1.01], p = 0.09) or amputation-free survival (HR 0.98 [0.92 to 1.03], p = 0.42), reintervention (RR 1.24 [0.74 to 2.07], p = 0.41), major amputation, (RR 1.16 [0.87 to 1.54], p = 0.31), or therapeutic crossover (RR 0.92 [0.37 to 2.26], p = 0.85). In conclusion, data from available RCTs suggest that there is no difference in clinical outcomes between endovascular-first and surgery-first revascularization strategies for CLTI. A planned patient-level meta-analysis may provide further insight.

Risk Factors for 30-day Hospital Readmissions After Peripheral Vascular Interventions in Peripheral Artery Disease Patients at the US-Mexico Border

Peripheral artery disease (PAD) is associated with high rates of readmission following endovascular interventions and contributes to a significant hospital readmission burden. Quality metrics like hospital readmissions affect hospital performance, but must adjust to local trends. Our primary goal was to evaluate risk factors and readmission rates post-percutaneous peripheral intervention in a US-Mexico border city, at a single tertiary university hospital. We performed a retrospective review of patients with PAD undergoing first time peripheral intervention from July 2015 to June 2020. Among 212 patients, 58% were readmitted with median 235-day follow-up (inter-quartile range (IQR) 42-924); 35.3% of readmissions occurred within 30 days, and 30.2% of those were within 7 days. Median time to readmission was 62 days. Active smokers had 84% higher risk of readmission (hazard ratio (HR) 1.84, 95% CI 1.23-2.74, P < .01). Other significant factors noted were insurance status-Medicaid or uninsured (HR 1.94, 95% CI 1.22-3.09), prior amputation (HR 1.69, 95% CI 1.13-2.54), heart failure, both preserved (HR 4.35, 95% CI 2.07-9.16) and reduced ejection fraction (HR 1.88, 95% CI 1.14-3.10). Below the knee, interventions were less likely to be readmitted (adjusted HR .64, 95% CI 0.42-.96). Readmission rates were unrelated to medication adherence.

Novel Glycomimetics Protect against Glycated Low-Density Lipoprotein-Induced Vascular Calcification In Vitro via Attenuation of the RAGE/ERK/CREB Pathway

Heparan sulphate (HS) can act as a co-receptor on the cell surface and alterations in this process underpin many pathological conditions. We have previously described the usefulness of mimics of HS (glycomimetics) in protection against β-glycerophosphate-induced vascular calcification and in the restoration of the functional capacity of diabetic endothelial colony-forming cells in vitro. This study aims to investigate whether our novel glycomimetic compounds can attenuate glycated low-density lipoprotein (g-LDL)-induced calcification by inhibiting RAGE signalling within the context of critical limb ischemia (CLI). We used an established osteogenic in vitro vascular smooth muscle cell (VSMC) model. Osteoprotegerin (OPG), sclerostin and glycation levels were all significantly increased in CLI serum compared to healthy controls, while the vascular calcification marker osteocalcin (OCN) was down-regulated in CLI patients vs. controls. Incubation with both CLI serum and g-LDL (10 µg/mL) significantly increased VSMC calcification vs. controls after 21 days, with CLI serum-induced calcification apparent after only 10 days. Glycomimetics (C2 and C3) significantly inhibited g-LDL and CLI serum-induced mineralisation, as shown by a reduction in alizarin red (AR) staining and alkaline phosphatase (ALP) activity. Furthermore, secretion of the osteogenic marker OCN was significantly reduced in VSMCs incubated with CLI serum in the presence of glycomimetics. Phosphorylation of cyclic AMP response element-binding protein (CREB) was significantly increased in g-LDL-treated cells vs. untreated controls, which was attenuated with glycomimetics. Blocking CREB activation with a pharmacological inhibitor 666-15 replicated the protective effects of glycomimetics, evidenced by elevated AR staining. In silico molecular docking simulations revealed the binding affinity of the glycomimetics C2 and C3 with the V domain of RAGE. In conclusion, these findings demonstrate that novel glycomimetics, C2 and C3 have potent anti-calcification properties in vitro, inhibiting both g-LDL and CLI serum-induced VSMC mineralisation via the inhibition of LDLR, RAGE, CREB and subsequent expression of the downstream osteogenic markers, ALP and OCN.

Interventional Treatment Options for the Prevention of Amputation in Patients With Lower Extremity Wounds From Peripheral Arterial Disease

BACKGROUND

Peripheral arterial disease and related lower extremity wounds are prominent causes of amputation. Revascularization may reduce amputation rates or the amputation margin more distally in patients with peripheral arterial disease who have wounds resulting from critical limb ischemia. This study examined the association of risk factors and intervention types with amputation rates in patients with critical lower extremity arterial disease.

METHODS

A total of 211 patients who underwent peripheral intervention because of foot wound were followed up for 12 months after the intervention. All patients had lower extremity wounds resulting from peripheral arterial disease. The effects of treatment approaches were compared in patients who underwent and did not undergo amputation.

RESULTS

Revascularization of the anterior tibial artery reduced the amputation rate by 6.52 times compared with occlusion. Posterior tibial artery revascularization reduced the amputation rate by 49.95 times.

CONCLUSION

In this study of percutaneous intervention methods for prevention of amputation, the most effective option was revascularization of the posterior tibial artery and anterior tibial artery. Considering these results, treatment of critical peripheral arterial disease can be cost-effective and efficient and may shorten procedure time.

Treatment Variability Among Patients Hospitalized for Chronic Limb-Threatening Ischemia: An Analysis of the 2016 to 2018 US National Inpatient Sample

BACKGROUND

Little is known about treatment variability across US hospitals for patients with chronic limb-threatening ischemia (CLTI).

METHODS AND RESULTS

Data were collected from the 2016 to 2018 National Inpatient Sample. All patients aged ≥18 years, admitted to nonfederal US hospitals with a primary diagnosis of CLTI, were identified. Patients were classified according to their clinical presentation (rest pain, skin ulceration, or gangrene) and were further characterized according to the treatment strategy used. The primary outcome of interest was variability in CLTI treatment, as characterized by the median odds ratio. The median odds ratio is defined as the likelihood that 2 similar patients would be treated with a given modality at 1 versus another randomly selected hospital. There were 15 896 (weighted n=79 480) hospitalizations identified where CLTI was the primary diagnosis. Medical therapy alone, endovascular revascularization ± amputation, surgical revascularization ± amputation, and amputation alone were used in 4057 (25%), 5390 (34%), 3733 (24%), and 2716 (17%) patients, respectively. After adjusting for both patient- and hospital-related factors, the median odds ratio (95% CI) for medical therapy alone, endovascular revascularization ± amputation, surgical revascularization ± amputation, any revascularization, and amputation alone were 1.28 (1.19-1.38), 1.86 (1.77-1.95), 1.65 (1.55-1.74), 1.37 (1.28-1.45), and 1.42 (1.27-1.55), respectively.

CONCLUSIONS

Significant variability in CLTI treatment exists across US hospitals and is not fully explained by patient or hospital characteristics.

Endovascular recanalization of infra-popliteal TASC C and TASC D lesions in patients with critical limb-threatening ischemia: a single-center experience

PURPOSE

The present study aims to (1) assess the technical success and limb salvage rates of endovascular therapy in patients with critical limb-threatening ischemia (CLTI) and infra-popliteal Trans-Atlantic Inter-Society Consensus (TASC) C/D lesions according to the updated 2015 TASC II classification and (2) to present our institutional experience.

METHODS

A single-center retrospective study was conducted on patients with TASC C/D CLTI who underwent endovascular treatment between 2012 and 2017. The follow-up protocol consisted of Doppler ultrasound conduction every 3 months for the first year unless patients showed symptoms of CLTI. Patients with at least 1 year of follow-up data were included in the study, and if applicable their 3-year results were evaluated in terms of primary patency, absence of amputation, amputation-free survival, and overall survival.

RESULTS

A total of 248 patients and 287 limbs (238 TASC D lesions and 49 TASC C lesions) were treated via infra-popliteal percutaneous transluminal angioplasty. The overall technical success was 87%, the primary patency rate was 41.5% in the first year, and the freedom from amputation rates were 80.8% in 1 year and 67.7% in 3 years.

CONCLUSION

In patients with infra-popliteal arterial occlusive diseases, endovascular treatment methods demonstrate a high rate of technical success and favorable outcomes in limb preservation.

Translational Relevance of Advanced Age and Atherosclerosis in Preclinical Trials of Biotherapies for Peripheral Artery Disease

Approximately 6% of adults worldwide suffer from peripheral artery disease (PAD), primarily caused by atherosclerosis of lower limb arteries. Despite optimal medical care and revascularization, many PAD patients remain symptomatic and progress to critical limb ischemia (CLI) and risk major amputation. Delivery of pro-angiogenic factors as proteins or DNA, stem, or progenitor cells confers vascular regeneration and functional recovery in animal models of CLI, but the effects are not well replicated in patients and no pro-angiogenic biopharmacological procedures are approved in the US, EU, or China. The reasons are unclear, but animal models that do not represent clinical PAD/CLI are implicated. Consequently, it is unclear whether the obstacles to clinical success lie in the toxic biochemical milieu of human CLI, or in procedures that were optimized on inappropriate models. The question is significant because the former case requires abandonment of current strategies, while the latter encourages continued optimization. These issues are discussed in the context of relevant preclinical and clinical data, and it is concluded that preclinical mouse models that include age and atherosclerosis as the only comorbidities that are consistently present and active in clinical trial patients are necessary to predict clinical success. Of the reviewed materials, no biopharmacological procedure that failed in clinical trials had been tested in animal models that included advanced age and atherosclerosis relevant to PAD/CLI.

Success of transmetatarsal amputation for limb salvage in patients with peripheral artery disease

Limb salvage is a difficult path for patients to travel as there is no guarantee of the outcome, often the major factor is perfusion. For patients who underwent transmetatarsal amputation (TMA), success rate is crucial as the next option is most likely a major amputation. We performed a 10 years (2010-2020) retrospective review of patients that underwent a TMA and had an angiogram or computed tomography angiography (CTA) perioperatively at the Dallas VA Medical Center. Failure after TMA was defined as a patient requiring a proximal amputation within 1 year. There were 125 TMAs performed between 2010 and 2020 at the institution. Forty-four (35.2%) patients had an angiogram/CTA peri-operative and met the inclusion criteria. Seventeen subjects (38.6%) had a higher level of amputation. Of the 17 failures, 2 (11.8%) patients had no patent vessel runoff to the foot, 9 (52.9%) had one vessel, 4 (23.5%) had two vessels, and 2 (11.8%) had three vessels runoff. One vessel runoff to the foot yielded a high rate of poor outcomes (56.3%) defined as a higher level of amputation. Two or more vessels runoff to the foot had over 75% success of limb salvage with a TMA.

Co-Delivery of Bioengineered Exosomes and Oxygen for Treating Critical Limb Ischemia in Diabetic Mice

Diabetic patients with critical limb ischemia face a high rate of limb amputation. Regeneration of the vasculature and skeletal muscles can salvage diseased limbs. Therapy using stem cell-derived exosomes that contain multiple proangiogenic and promyogenic factors represents a promising strategy. Yet the therapeutic efficacy is not optimal because exosomes alone cannot efficiently rescue and recruit endothelial and skeletal muscle cells and restore their functions under hyperglycemic and ischemic conditions. To address these limitations, we fabricated ischemic-limb-targeting stem cell-derived exosomes and oxygen-releasing nanoparticles and codelivered them in order to recruit endothelial and skeletal muscle cells, improve cell survival under ischemia before vasculature is established, and restore cell morphogenic function under high glucose and ischemic conditions. The exosomes and oxygen-releasing nanoparticles, delivered by intravenous injection, specifically accumulated in the ischemic limbs. Following 4 weeks of delivery, the exosomes and released oxygen synergistically stimulated angiogenesis and muscle regeneration without inducing substantial inflammation and reactive oxygen species overproduction. Our work demonstrates that codelivery of exosomes and oxygen is a promising treatment solution for saving diabetic ischemic limbs.

Single-cell transcriptomics identifies adipose tissue CD271+ progenitors for enhanced angiogenesis in limb ischemia

Therapeutic angiogenesis using mesenchymal stem/stromal cell grafts have shown modest and controversial effects in preventing amputation for patients with critical limb ischemia. Through single-cell transcriptomic analysis of human tissues, we identify CD271+ progenitors specifically from subcutaneous adipose tissue (AT) as having the most prominent pro-angiogenic gene profile distinct from other stem cell populations. AT-CD271+ progenitors demonstrate robust in vivo angiogenic capacity over conventional adipose stromal cell grafts, characterized by long-term engraftment, augmented tissue regeneration, and significant recovery of blood flow in a xenograft model of limb ischemia. Mechanistically, the angiogenic capacity of CD271+ progenitors is dependent on functional CD271 and mTOR signaling. Notably, the number and angiogenic capacity of CD271+ progenitors are strikingly reduced in insulin-resistant donors. Our study highlights the identification of AT-CD271+ progenitors with in vivo superior efficacy for limb ischemia. Furthermore, we showcase comprehensive single-cell transcriptomics strategies for identification of suitable grafts for cell therapy.

Adipose-Derived Mesenchymal Stem Cells Protect Endothelial Cells from Hypoxic Injury by Suppressing Terminal UPR In Vivo and In Vitro

Adipose-derived stem cells (ASCs) have been used as a therapeutic intervention for peripheral artery disease (PAD) in clinical trials. To further explore the therapeutic mechanism of these mesenchymal multipotent stromal/stem cells in PAD, this study was designed to test the effect of xenogeneic ASCs extracted from human adipose tissue on hypoxic endothelial cells (ECs) and terminal unfolded protein response (UPR) in vitro and in an atherosclerosis-prone apolipoprotein E-deficient mice (ApoE-/- mice) hindlimb ischemia model in vivo. ASCs were added to Cobalt (II) chloride-treated ECs; then, metabolic activity, cell migration, and tube formation were evaluated. Fluorescence-based sensors were used to assess dynamic changes in Ca2+ levels in the cytosolic- and endoplasmic reticulum (ER) as well as changes in reactive oxygen species. Western blotting was used to observe the UPR pathway. To simulate an acute-on-chronic model of PAD, ApoE-/- mice were subjected to a double ligation of the femoral artery (DLFA). An assessment of functional recovery after DFLA was conducted, as well as histology of gastrocnemius. Hypoxia caused ER stress in ECs, but ASCs reduced it, thereby promoting cell survival. Treatment with ASCs ameliorated the effects of ischemia on muscle tissue in the ApoE-/- mice hindlimb ischemia model. Animals showed less muscle necrosis, less inflammation, and lower levels of muscle enzymes after ASC injection. In vitro and in vivo results revealed that all ER stress sensors (BIP, ATF6, CHOP, and XBP1) were activated. We also observed that the expression of these proteins was reduced in the ASCs treatment group. ASCs effectively alleviated endothelial dysfunction under hypoxic conditions by strengthening ATF6 and initiating a transcriptional program to restore ER homeostasis. In general, our data suggest that ASCs may be a meaningful treatment option for patients with PAD who do not have traditional revascularization options.

Clinical Implications of Diabetic Peripheral Neuropathy in Primary Infrapopliteal Angioplasty Approach for Neuro-Ischemic Foot Wounds

BACKGROUND

To assess the clinical effects of diabetic peripheral neuropathy (DPN) in patients with chronic limb-threatening ischemia (CLTI) treated by primary infrapopliteal angioplasty for neuro-ischemic Rutherford 5, foot wounds.

MATERIALS AND METHODS

Over a 10-year period (2009-2019), a series of 304 diabetic ischemic limbs adding or not evincible neuropathic affectation were treated by primary infrapopliteal angioplasty and their files were retrospectively reviewed. Mean length of treated arterial lesions was 6.1 cm (range 1-22 cm). Inferior limb vibration perception threshold diagnostic was performed for comparing and scoring detectable DPN in all studied diabetic patients (classed from 0 to 10 points). There were 19% limbs with normal (0-1 points) perception (group 1), 55% others with "mild" and "moderate" (2-6 points) neuropathic impairment (group 2), and 26% limbs showing "severe" (7-10 points) DPN (group 3).

RESULTS

Primary infrapopliteal angioplasty succeeded in 89% cases in group 1, in 82% in group 2, and in 68% of limbs in group 3. This latest group assembled the heaviest neuropathic affectation and arterial calcifications and proved the lowest clinical benefit at 36 months: 35% (95% confidence interval [CI]=22% to 48%) of primary patency, 36% (95% CI=22% to 50%) wound healing, and 54% (95% CI=39% to 69%) limb preservation rates. A comparison between groups 1 vs 3 and 2 vs 3 of primary patency (p=0.014 and p=0.043), tissue healing (p=0.049 and p=0.01), and limb salvage (p=0.006 and p=0.023) proved significant, yet without statistical weight for group 1 vs 2 (p>0.05). Overall survival was not significantly affected between groups (p=0.34).

CONCLUSION

The presence of severe DPN may jeopardize the results of infrapopliteal angioplasty in terms of patency, tissue cicatrization, and limb preservation, yet without significance on survival of these patients. When present, DPN requires appropriate stratification as specific indicator in CLTI treatment.

Delayed rupture of peroneal artery pseudoaneurysm following endovascular treatment in a patient with chronic limb-threatening ischemia: A case report

Below-the-knee (BTK) pseudoaneurysms that occur after endovascular therapy (EVT) and result in delayed rupture have rarely been reported. In this report, we present a rare case of an 86-year-old man with chronic limb-threatening ischemia who developed delayed rupture of an idiopathic pseudoaneurysm of the peroneal artery (PA) following EVT. The PA chronic total occlusion (CTO) was successfully crossed using a guidewire via an antegrade approach, however, subintimal crossing was confirmed by intravascular ultrasound. Balloon angioplasty was then performed using an appropriately sized balloon, resulting in successful recanalization of the PA CTO with minor dissection and no complications. Postoperatively, the patient's condition was stable until he suddenly complained of right calf pain 10 days after EVT. Computed tomography revealed a rupture of the PA pseudoaneurysm. Urgent angiography revealed two pseudoaneurysms, one saccular and the other spindle-shaped. The ruptured saccular aneurysm was successfully excluded through coil embolization and stent graft placement. To the best of our knowledge, this is the first reported case of delayed rupture of a BTK pseudoaneurysm following EVT. Balloon angioplasty in the subintimal space can lead to the formation of a pseudoaneurysm and its delayed rupture.

Adipose-Derived Stem Cells to Treat Ischemic Diseases: The Case of Peripheral Artery Disease

Critical limb ischemia incidence and prevalence have increased over the years. However, there are no successful treatments to improve quality of life and to reduce the risk of cardiovascular and limb events in these patients. Advanced regenerative therapies have focused their interest on the generation of new blood vessels to repair tissue damage through the use of stem cells. One of the most promising sources of stem cells with high potential in cell-based therapy is adipose-derived stem cells (ASCs). ASCs are adult mesenchymal stem cells that are relatively abundant and ubiquitous and are characterized by a multilineage capacity and low immunogenicity. The proangiogenic benefits of ASCs may be ascribed to: (a) paracrine secretion of proangiogenic molecules that may stimulate angiogenesis; (b) secretion of microvesicles/exosomes that are also considered as a novel therapeutic prospect for treating ischemic diseases; and (c) their differentiation capability toward endothelial cells (ECs). Although we know the proangiogenic effects of ASCs, the therapeutic efficacy of ASCs after transplantation in peripheral artery diseases patients is still relatively low. In this review, we evidence the potential therapeutic use of ASCs in ischemic regenerative medicine. We also highlight the main challenges in the differentiation of these cells into functional ECs. However, significant efforts are still needed to ascertain relevant transcription factors, intracellular signaling and interlinking pathways in endothelial differentiation.

Histidine Triad Nucleotide-Binding Protein 1 Improves Critical Limb Ischemia by Regulating Mitochondrial Homeostasis

Critical limb ischemia (CLI) is a common complication of diabetes mellitus that typically occurs in the later stages of the disease. Vascularization is indeed an important physiological process involving the formation of new blood vessels from existing ones. It occurs in response to various normal and pathophysiological conditions, and one of its critical roles is to compensate for inadequate oxygen supply, which is often seen in situations like chronic limb ischemia (CLI). Histidine triad nucleotide-binding protein 1 (Hint1) is a member of the Hint family that has been shown to attenuate cardiac hypertrophy, but its role in vascularization still needs to be clarified. In this study, we investigated the role of Hint1 in CLI. We found that Hint1 is significantly reduced in the muscle tissue of STZ-induced diabetic mice and high-glucose (HG)-treated endothelial cells (ECs). Hint1 deletion impaired blood flow recovery and vascularization, whereas Hint1 overexpression promoted these processes. In addition, our in vitro study showed that Hint1 deficiency aggravated mitochondrial dysfunction in ECs, as evidenced by impaired mitochondrial respiration, decreased mitochondrial membrane potential, and increased reactive oxygen species. Our findings suggest that Hint1 deficiency impairs blood perfusion by damaging mitochondrial function and that Hint1 may represent a potential therapeutic target for treating CLI.

Application of 3D Printing Insole by Hemodynamics in Older Patients with Critical Limb Ischemia: Protocol for a Randomized Clinical Trial

Introduction

Critical limb ischemia (CLI) is a severe condition characterized by inadequate blood flow to the lower extremities, often leading to tissue damage and amputation. CLI is characterized by microcirculatory dysfunction, muscle tissue necrosis, and inflammation. Patients may suffer from the traumatic pain and the increase of plantar pressure, and foot care for patients with CLI has become the "last mile" to improve their life quality. Traditional shoe insoles often lack individual customization, failing to address the unique anatomical needs and hemodynamic characteristics of patients. The study aims to investigate the effects of this innovative intervention on improving the clinical outcomes, and quality of life in CLI patients.

Methods and Analysis

This Critical Limb Ischemia Hemodynamic Insole Study is a randomized controlled study performed to explore the effect of a 3D printing insole on foot care of CLI patients. This study recruitment began on November 1, 2021. Patients with CLI confirmed by clinical symptoms and imaging were recruited as the research objects. Participants will be randomly assigned to either the experimental group, which will receive 3D-printed insoles customized based on their hemodynamics, or the control group, which will receive traditionally manufactured insoles. Both groups were followed up for up to 24 months after surgery, including claudication distance, claudication time, pain score, rehospitalization, etc.

Trial Registration Number

ChiCTR2100051857.

Femorotibial Bypass Sutured on Bovine Pericardium Patch of the Femoral Artery for Bypass Inflow: A Case Report

A 72-year-old man presented with intermittent claudication and a foot ulcer. Computed tomography revealed severe calcification and occlusion of the left femoral artery and calcification and stenosis from the superficial femoral artery to the popliteal artery. Thromboendarterectomy (TEA) and anterior reconstruction of the femoral artery with a bovine pericardium patch were performed. We sutured the great saphenous vein on the bovine pericardium patch for bypass inflow after creating an anastomosis hole with a puncher and performed an in situ femorotibial bypass. This technique helped us achieve a smooth and clean anastomosis. In situ vein graft anastomosis might be difficult on severely atherosclerotic femoral artery after TEA and difficult anastomosis increases the risk of bypass occlusion. Anastomosis on the bovine pericardium patch for bypass inflow might ensure smooth and clean anastomosis in patients with severe atherosclerosis of the femoral artery.

ACR Appropriateness Criteria® Sudden Onset of Cold, Painful Leg: 2023 Update

Acute onset of a cold, painful leg, also known as acute limb ischemia, describes the sudden loss of perfusion to the lower extremity and carries significant risk of morbidity and mortality. Acute limb ischemia requires rapid identification and the management of suspected vascular compromise and is inherently driven by clinical considerations. The objectives of initial imaging include confirmation of diagnosis, identifying the location and extent of vascular occlusion, and preprocedural/presurgical planning. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Continuous Tunneled Infraclavicular Nerve Catheter for Palliative Management of Critical Limb Ischemia: A Case Report

Critical limb ischemia (CLI) is limb pain occurring at rest or impending limb loss as a result of lack of blood flow to the affected extremity. CLI pain is challenging to control despite multimodal pharmacologic analgesia and surgical intervention. We describe the successful use of a continuous local anesthetic infusion via an infraclavicular nerve catheter to control severe refractory ischemic upper limb pain in a patient with metastatic lung cancer for whom surgical and pharmacological intervention was unsuccessful. As her opioid requirements increased due to worsening ischemic pain, she subsequently developed opioid toxicity, hence prompting the palliative use of a tunneled infraclavicular nerve catheter under ultrasound guidance to minimize opioid requirements. Her opioid requirements tailed down subsequently with the successful insertion of the infraclavicular nerve catheter and she remained pain free till her death. Palliative use of nerve catheters is a safe and an effective alternative in patients with refractory cancer pain, and we describe our methods to prolong its use and minimizing its associated long-term complications.

An H2 S-BMP6 Dual-Loading System with Regulating Yap/Taz and Jun Pathway for Synergistic Critical Limb Ischemia Salvaging Therapy

Critical limb ischemia, the final course of peripheral artery disease, is characterized by an insufficient supply of blood flow and excessive oxidative stress. H2 S molecular therapy possesses huge potential for accelerating revascularization and scavenging intracellular reactive oxygen species (ROS). Moreover, it is found that BMP6 is the most significantly up-expressed secreted protein-related gene in HUVECs treated with GYY4137, a H2 S donor, based on the transcriptome analysis. Herein, a UIO-66-NH2 @GYY4137@BMP6 co-delivery nanoplatform to strengthen the therapeutic effects of limb ischemia is developed. The established UIO-66-NH2 @GYY4137@BMP6 nanoplatform exerts its proangiogenic and anti-oxidation functions by regulating key pathways. The underlying molecular mechanisms of UIO-66-NH2 @GYY4137@BMP6 dual-loading system lie in the upregulation of phosphorylated YAP/TAZ and Jun to promote HUVECs proliferation and downregulation of phosphorylated p53/p21 to scavenge excessive ROS. Meanwhile, laser-doppler perfusion imaging (LDPI), injury severity evaluation, and histological analysis confirm the excellent therapeutic effects of UIO-66-NH2 @GYY4137@BMP6 in vivo. This work may shed light on the treatment of critical limb ischemia by regulating YAP, Jun, and p53 signaling pathways based on gas-protein synergistic therapy.

Technical outcomes of below-the-elbow revascularization for upper extremity critical limb ischemia

OBJECTIVES

This study aims to report the technical results of below-the-elbow arterial revascularization in patients with critical hand ischemia.

METHODS

We retrospectively identified upper extremity critical limb ischemia patients treated with below-the-elbow arterial intervention between 2013 and 2017. Patient demographics, comorbidities, and procedural data were reviewed and technical success was evaluated.

RESULTS

Seven patients with 12 arteries that were affected by critical hand ischemia were treated. All patients had a history of end-stage renal disease. The technical success rate was 83.3%. There were no major or minor complications. The average follow-up duration was 9 months (2-26 months). One patient underwent a digital amputation at 8 months.

CONCLUSION

Arterial revascularization of the below-the-elbow arteries for critical hand ischemia is safe and technically feasible.

Safety and Effectiveness of Excimer Laser Ablation Combined With Drug-Coated Balloon for Atherosclerotic Obliterans in the Lower Extremity

PURPOSE

To evaluate the safety and effectiveness of excimer laser ablation (ELA) combined with drug-coated balloon (DCB) for atherosclerotic obliterans (ASO) of the lower extremities.

MATERIALS AND METHODS

From June 2019 to December 2020, all eligible patients were enrolled. Demographics, characteristics of lesions, complications, and follow-up information were collected and analyzed. The primary endpoint was major amputation-free survival (MAFS). Secondary endpoints included technical success, primary patency, bailout stent, distal embolization, target lesion reintervention (TLR), and ulcer healing rate. Major amputation-free survival and primary patency were calculated by Kaplan-Meier analysis.

RESULTS

A total of 71 patients were enrolled. Forty-eight (81.7%) patients presented critical limb ischemia (CLI) and 48.6% of them was calcification class 4 according to Peripheral Arterial Calcium Scoring System (PACSS). Chronic totally occluded (CTO) disease was the most common lesion in 66.0% of them and superficial femoral artery (SFA) was the most common segment in 59.6%. Technical success rate was 93.0%. One-year follow-up was finished in 25 (35.2%) patients. The primary patency and MAFS were 92.0%±27.6% and 96.0%±20.0% at 12 months, respectively. During the mean follow-up of 9.4±4.3 months, clinically-driven TLR occurred in 2 (2.8%) patients, and major and minor amputation occurred in 2 (2.8%) and 1 (1.4%) patient, respectively.

CONCLUSION

The early results demonstrated that ELA was an effective treatment in de novo, in-stent restenosis (ISR) and CTO lesions. Meanwhile, ELA could prepare the lumen for the use of DCB and reduce the implantation of stents, especially in segments unsuitable for stenting. Mid-term and long-term results need to be awaited.

Dapagliflozin promotes angiogenesis in hindlimb ischemia mice by inducing M2 macrophage polarization

Critical limb ischemia (CLI) is associated with a higher risk of limb amputation and cardiovascular death. Dapagliflozin has shown great potential in the treatment of cardiovascular disease. However, the effects of dapagliflozin on CLI and the underlying mechanisms have not been fully elucidated. We evaluated the effect of dapagliflozin on recovery from limb ischemia using a mouse model of hindlimb ischemia. The flow of perfusion was evaluated using a laser Doppler system. Tissue response was assessed by analyzing capillary density, arterial density, and the degree of fibrosis in the gastrocnemius muscle. Immunofluorescence and Western blot were used to detect the expression of macrophage polarization markers and inflammatory factors. Our findings demonstrate the significant impact of dapagliflozin on the acceleration of blood flow recovery in a hindlimb ischemia mouse model, concomitant with a notable reduction in limb necrosis. Histological analysis revealed that dapagliflozin administration augmented the expression of key angiogenic markers, specifically CD31 and α-SMA, while concurrently mitigating muscle fibrosis. Furthermore, our investigation unveiled dapagliflozin's ability to induce a phenotypic shift of macrophages from M1 to M2, thereby diminishing the expression of inflammatory factors, including IL-1β, IL-6, and TNF-α. These effects were partially mediated through modulation of the NF-κB signaling pathway. Lastly, we observed that endothelial cell proliferation, migration, and tube-forming function are enhanced in vitro by utilizing a macrophage-conditioned medium derived from dapagliflozin treatment. Taken together, our study provides evidence that dapagliflozin holds potential as an efficacious therapeutic intervention in managing CLI by stimulating angiogenesis, thereby offering a novel option for clinical CLI treatment.

Limb Salvage and Survival in Chronic Limb-Threatening Ischemia: The Need for a Fast-Track Team-Based Approach

Chronic limb-threatening ischemia (CLTI) represents the end-stage form of peripheral arterial disease (PAD) and is associated with a very poor prognosis and high risk of limb loss and mortality. It can be considered very similar to a terminal cancer disease, reflecting a large impact on quality of life and healthcare costs. The aim of this study is to offer an overview of the relationship between CLTI, limb salvage, and mortality, with a focus on the need of a fast-track team-based management that is a driver to achieve better survival results. This review can be useful to improve management of this growing impact disease, and to promote the standardisation of care and communication between specialist and non-specialist healthcare professionals.

Infrapopliteal 3-Vessel Occlusive Disease Is the Only Predictor of Wound Recurrence After Complete Wound Healing via Endovascular Therapy in Patients With Chronic Limb-threatening Ischemia

PURPOSE

To determine the predictors of wound recurrence after complete wound healing in patients with chronic limb-threatening ischemia (CLTI) who underwent endovascular therapy (EVT) for infrapopliteal (IP) lesions with consideration of IP arterial anatomic severity, including classification by the Global Limb Anatomic Staging System (GLASS).

MATERIALS AND METHODS

This retrospective single-center study assessed patients with de novo CLTI limbs with tissue loss treated via EVT for IP lesions from September 2016 to May 2021. Among these patients, 149 consecutive limbs from 133 patients who achieved complete wound healing were enrolled. The Kaplan-Meier method was used to estimate the wound recurrence rate after complete wound healing. The Cox proportional hazard model was used to assess the association between baseline characteristics and wound recurrence.

RESULTS

The cumulative wound recurrence rate 1 year after complete wound healing was 30%. The mean time for wound recurrence was 7±5 months. Only IP arterial anatomic characteristics remained as a predictor of wound recurrence, whereas wound status and management, including the Wound, Ischemia, and foot Infection (WIfI) clinical stage and minor amputation, were not associated with wound recurrence. Multivariate analysis revealed independent associations between wound recurrence and IP 3-vessel occlusive disease (hazard ratio, 2.97; 95% confidence interval, 1.39-6.35), but not poor below-the-ankle runoff, IP Peripheral Arterial Calcium Scoring System (PACSS) grade, and the GLASS IP grade.

CONCLUSION

The only independent predictor of wound recurrence after complete wound healing via EVT in patients with CLTI was IP 3-vessel occlusive disease.

CLINICAL IMPACT

In patients with chronic limb-threatening ischemia (CLTI), wound recurrence after complete wound healing remains a challenge, and studies focused exclusively on wound recurrence are still limited. The present study aimed to determine the risk factors for wound recurrence after complete wound healing in patients with CLTI who underwent endovascular therapy (EVT) for infrapopliteal (IP) lesions, with consideration of IP arterial anatomic severity for the first time. The results showed that IP 3-vessel occlusive disease was the only predictor of wound recurrence, whereas wound status/management and other arterial anatomic characteristics including WIfI clinical stages and GLASS grades were not predictors.

Racial and Ethnic Disparities in Treatment of Critical Limb Ischemia: A National Perspective

Background Recent guidelines have emphasized the use of medical management, early diagnosis, and a multidisciplinary team to effectively treat patients with critical limb ischemia (CLI). Previous literature briefly highlighted the current racial disparities in its intervention. Herein, we analyze the trend over a 14-year time period to investigate whether the disparities gap in CLI management is closing. Methods and Results The National Inpatient Sample was queried between 2005 and 2018 for hospitalizations involving CLI. Nontraumatic amputations and revascularization were identified. Utilization trends of these procedures were compared between races (White, Black, Hispanic, Asian and Pacific Islander, Native American, and Other). Multivariable regression assessed differences in race regarding procedure usage. There were 6 904 562 admissions involving CLI in the 14-year study period. The rate of admissions in White patients who received any revascularization decreased by 0.23% (P<0.001) and decreased by 0.25% (P=0.025) for Asian and Pacific Islander patients. Among all patients, the annual rate of admission in White patients who received any amputation increased by 0.21% (P<0.001), increased by 0.19% (P=0.001) for Hispanic patients, and increased by 0.19% (P=0.012) for the Other race patients. Admissions involving Black, Hispanic, Asian and Pacific Islander, or Other race patients had higher odds of receiving any revascularization compared with White patients. All races had higher odds of receiving major amputation compared with White patients. Conclusions Our analysis highlights disparities in CLI treatment in our nationally representative sample. Non-White patients are more likely to receive invasive treatments, including major amputations and revascularization for CLI, compared with White patients.

Association of 2D Perfusion Angiography and Wound Healing Rate in Combined Femoro-popliteal and Below-the-Knee Lesions in Ischemic Patients Undergoing Isolated Femoro-popliteal Endovascular Revascularization

The aim of this study was to demonstrate the association between 2-dimensional (2D) perfusion angiography and wound healing rate in patients with combined femoro-popliteal and below-the-knee lesions in critical limb-threatening ischemia (CLTI) and foot wounds undergoing isolated femoro-popliteal endovascular revascularization. Between January and June 2019, 24 patients with multilevel CLTI and foot wounds underwent isolated femoro-popliteal endovascular revascularization. In all of them, an assessment of foot perfusion by 2D perfusion angiography was performed. To evaluate the foot perfusion, a region of interest was identified, and time-density curves were calculated. Changes of the overall time-density curves were evaluated together with transcutaneous oximetry (TcPO2) using bivariate correlation (Pearson correlation coefficient) and associated with 6-month wound healing. The mean increase of time-density curves was 212.2% (range from +9.8% to +1984.9%) and the mean increase of TcPO2 was 116.4% (range from -4.7% to 485.7%). No significant association between time-density curves and TcPO2 values (Pearson correlation coefficient: -0.24) was observed (P = .3). At 6 months, wound healing occurred in 15 of 24 (62.5%) patients. In conclusion, this preliminary experience confirmed that 2D perfusion angiography associates with wound healing rate in CLTI patients with ischemic foot wounds and combined femoro-popliteal and below-the-knee lesions who are undergoing isolated femoro-popliteal endovascular revascularization. No association between time-density curves and TcPO2 values was observed.

PCSK9 Promotes Hypoxia-Induced EC Pyroptosis by Regulating Smac Mitochondrion-Cytoplasm Translocation in Critical Limb Ischemia

Hypoxia-induced endothelial cell death and impaired angiogenesis are the main pathophysiological features of critical limb ischemia. Mechanistically, proprotein convertase subtilisin/kexin type 9 (PCSK9) promoted Smac translocation from mitochondria to the cytoplasm. Inhibition of Smac release into the cytoplasm attenuated PCSK9-mediated hypoxia-induced pyroptosis. Functionally, PCSK9 overexpression impaired angiogenesis in vitro and reduced blood perfusion in mice with lower limb ischemia, but the effect was reversed by PCSK9 inhibition. This study demonstrates that PCSK9 aggravates pyroptosis by regulating Smac mitochondrion-cytoplasm translocation in the vascular endothelium, providing novel insights into PCSK9 as a potential therapeutic target in critical limb ischemia.

Mesenchymal Stem/Stromal Cells for Therapeutic Angiogenesis

Mesenchymal stem/stromal cells (MSCs) are known to possess medicinal properties to facilitate vascular regeneration. Recent advances in the understanding of the utilities of MSCs in physiological/pathological tissue repair and technologies in isolation, expansion, and enhancement strategies have led to the use of MSCs for vascular disease-related treatments. Various conditions, including chronic arterial occlusive disease, diabetic ulcers, and chronic wounds, cause significant morbidity in patients. Therapeutic angiogenesis by cell therapy has led to the possibilities of treatment options in promoting angiogenesis, treating chronic wounds, and improving amputation-free survival. Current perspectives on the options for the use of MSCs for therapeutic angiogenesis in vascular research and in medicine, either as a monotherapy or in combination with conventional interventions, for treating patients with peripheral artery diseases are discussed in this review.

Ten-year experience with use of cryopreserved allografts for redo infrapopliteal bypass

INTRODUCTION

The aim of this study is to report the early and late outcomes of cryopreserved saphenous vein (CSV) in redo infrainguinal bypass and to investigate possible predictors of primary patency loss.

METHODS

All patients who underwent a redo bypass for critical limb ischemia from January 2010 to December 2020 were reviewed. Early and late complications were analyzed and included. The endpoints of the study were all cause mortality, major limb amputation, and primary patency (PP).

RESULTS

Data were collected from 95 patients. Among the entire cohort, 16 (16.8%) patients received a cryopreserved vessel bypass with anastomosis in the popliteal artery and 79 (83.2%) patients had cryopreserved vessel bypasses with distal anastomosis in tibial vessels. Median duration of follow-up was 73 months; during this, period estimated survival at 5 years was 80.5 ± 4% (95% CI, 78.0-91.2) and estimates of freedom from limb amputation was 90.3 ± 3.2% (95% CI, 87.3-98.1). Overall, the estimated primary patency of the bypass was 43.7 ± 6.7% (95% CI, 30.2-51.4). On multivariable analysis, intraprocedural tibial vessel angioplasty (HR = 2.3, p = 0.01), distal anastomosis in tibial vessels (HR = 3.6, p = 0.36), and the use of a composite graft (HR = 2.4, p = 0.01) were independently associated with loss of PP.

CONCLUSIONS

The use of CSV in redo bypass is an effective strategy in salvaging threatened lower extremities and in preventing or delaying limb amputation. Our results confirm that further attempts at revascularization are generally appropriate, even in technically changing patients.

Stem Cell Therapy in Critical Limb Ischemia

Critical limb ischemia (CLI), a serious outcome of peripheral artery disease, is frequently associated with morbid outcomes. The available treatment modalities do not provide satisfactory results, leading to marked morbidities such as joint contracture and amputations, resulting in a high economic burden. The peripheral vascular disease tends to cause more morbidity in patients with diabetes and atherosclerosis, given the pre-existing compromised perfusion of medium and small vessels in diabetic patients. With surgical procedures, the chance of vascular compromise further increases, inducing a significantly greater rate of amputation. Hence, the need for nonsurgical treatment modalities such as stem cell therapy (SCT), which promotes angiogenesis, is warranted. In CLI, SCT acts through neovascularization and the development of collateral arteries, which increases blood supply to the soft tissues of the ischemic limb, providing satisfactory outcomes. An electronic database search was performed in PubMed, SCOPUS, EMBASE, and ScienceDirect to identify published clinical trial data, research studies, and review articles on stem cell therapy in critical limb ischemia. The search resulted in a total of 2391 results. Duplicate articles screening resulted in 565 articles. In-depth screening of abstracts and research titles excluded 520 articles, yielding 45 articles suitable for full-text review. On review of full text, articles with overlapping and similar results were filtered, ending in 25 articles. SCT promotes arteriogenesis, and bone marrow-derived mesenchymal stromal cells produce significant effects like reduced morbidity, improved amputation-free survival (AFS ) rate, and improved distal perfusion even in "no-option" CLI patients. SCT is a promising treatment modality for CLI patients, even in those in whom endovascular and revascularization procedures are impossible. SCT assures a prolonged AFS rate, improved distal perfusion, improved walking distances, reduced amputation rates, and increased survival ratio, and is well-tolerated.

Role of Percutaneous Deep Venous Arterialization for Patients with Chronic Limb-threatening Ischemia

Efficacy of percutaneous deep venous arterialization (pDVA) has been reported for patients with no-option chronic limb-threatening ischemia (CLTI). In the countries where a manufactured device dedicated for pDVA has not been reimbursed, pDVA using the off-the-shelf technique has alternatively spread. The off-the-shelf techniques for arteriovenous fistula (AVF) creation reported are as follows: AV spear technique, venous arterialization simplified technique (VAST), and a use of penetration guidewire or a reentry device. Technical success rates of the procedures are similar to those using the dedicated device. pDVA could be a last resort for the patients with no-option CLTI, including those suffering from stump ulcer after major limb amputation or those with occluded surgical bypass.

Predictors of Revascularization in Lower-Extremity Peripheral Artery Disease: Insights From the PORTRAIT Study

BACKGROUND

Peripheral artery disease (PAD) guidelines recommend revascularization only for patients with lifestyle-limiting claudication that is refractory to goal-directed medical therapy (class IIA, level of evidence A). However, real-world invasive treatment patterns and predictors of revascularization in patients with symptomatic lower-extremity PAD are still largely unknown.

AIM

We aimed to examine rates, patient-level predictors, and site variability of early revascularization in patients with new or worsening PAD symptoms.

METHODS

Among patients with new-onset or recent exacerbation of PAD in the 10-center Patient-centered Outcomes Related to TReatment practices in peripheral Arterial disease: Investigating Trajectories (PORTRAIT) study enrolled between June 2011 and September 2015, we classified early revascularization (endovascular or surgical) as procedures being performed within 3 months of presentation. Hierarchical logistic regression was used to identify patient characteristics associated with early revascularization. Variability across sites was estimated using the median odds ratio (OR).

RESULTS

Among 797 participants, early revascularization procedures were performed in 224 (28.1%). Rutherford class 3 (vs Rutherford class 1; OR=1.86, 95% confidence interval [CI] 1.04-3.33) and having lesions in both iliofemoral and below-the-knee arterial segments (vs below the knee only; OR=1.75, 95% CI: 1.15-2.67) were associated with a higher odds of revascularization. Longer PAD duration >12 months (vs 1-6 months; OR=0.50, 95% CI: 0.32-0.77), higher ankle-brachial index scores (per 0.1 unit increase; OR=0.86, 95% CI: 0.78-0.96), and higher Peripheral Artery Questionnaire Summary scores (per 10 unit increase; OR=0.89, 95% CI: 0.80-0.99) were associated with a lower odds of revascularization. The raw rates for revascularization in different sites ranged from 6.25% to 66.28%, and the median OR was 1.88, 95% CI: 1.38-3.57.

CONCLUSIONS

About 1 in 3 patients with symptomatic PAD received early revascularization. A more extensive disease and symptom burden were the main predictors of receiving early revascularization in PAD. There was significant site variability in revascularization patterns, and further studies will better understand the source of this variability and optimal selection criteria for early revascularization.

CLINICAL IMPACT

Real world patterns and predictors of early revascularization in peripheral artery disease are not well understood. In this retrospective analysis of the POTRAIT study, about 1 out of 3 patients with PAD symptoms received early revascularization, with significant site variability. A more extensive disease and symptom burden were the main predictors of receiving early revascularization in PAD.

Effect of Cilostazol on Patients With Diabetes Who Underwent Endovascular Treatment for Peripheral Artery Disease

Background No large-scale study has compared the clinical impact of triple antiplatelet therapy (TAPT: aspirin, clopidogrel, and cilostazol) and dual antiplatelet therapy (DAPT) on adverse limb events in patients with diabetes after endovascular therapy (EVT) for peripheral artery disease. Thus, we investigate the effect of cilostazol added to a DAPT on the clinical outcomes after EVT in patients with diabetes using a nationwide, multicenter, real-world registry. Methods and Results A total of 990 patients with diabetes who underwent EVT were enrolled from the retrospective cohorts of a Korean multicenter EVT registry and were divided according to the antiplatelet regimen (TAPT [n=350; 35.4%] versus DAPT [n=640; 64.6%]). After propensity score matching based on clinical characteristics, a total of 350 pairs were compared for clinical outcomes. The primary end points were major adverse limb events, a composite of major amputation, minor amputation, and reintervention. For the matched study groups, the lesion length was 125.4±102.0 mm, and severe calcification was observed in 47.4%. The technical success rate (96.9% versus 94.0%; P=0.102) and the complication rate (6.9% versus 6.6%; P>0.999) were similar between the TAPT and DAPT groups. At 2-year follow-up, the incidence of major adverse limb events (16.6% versus 19.4%; P=0.260) did not differ between the 2 groups. However, the TAPT group showed less minor amputation than the DAPT group (2.0% versus 6.3%; P=0.004). In multivariate analysis, TAPT was an independent predictor of minor amputation (adjusted hazard ratio, 0.354 [95% CI, 0.158-0.794]; P=0.012). Conclusions In patients with diabetes undergoing EVT for peripheral artery disease, TAPT did not decrease the incidence of major adverse limb events but may be associated with a decreased risk of minor amputation.

Arterial Thrombosis in Patients with Acute Myeloid Leukemia: Incidence and Risk Factors

BACKGROUND

Patients with hematological malignancies have an increased risk of arterial thrombotic events (ATEs) after diagnosis, compared to matched controls without cancer. However, data about incidence and risk factors for ATE development in patients with acute myeloid leukemia (AML) are missing.

AIM

The objectives of this study were to determine the incidence of ATE in non-promyelocytic-AML patients and to define the potential risk factors for ATE development.

METHODS

We conducted a retrospective cohort study of adult patients with newly diagnosed AML. The primary outcome was the occurrence of confirmed ATE, defined as myocardial infarction, stroke or critical limb ischemia.

RESULTS

Out of 626 eligible AML patients, 18 (2.9%) patients developed ATE in the median time of 3 (range: 0.23-6) months. Half of these patients died due to ATE complications. Five parameters were predictors of ATE: BMI > 30 (p = 0.000, odds ratio [OR] 20.488, 95% CI: 6.581-63.780), prior history of TE (p = 0.041, OR 4.233, 95% CI: 1.329-13.486), presence of comorbidities (p = 0.027, OR 5.318, 95% CI: 1.212-23.342), presence of cardiovascular comorbidities (p < 0.0001, OR 8.0168, 95% CI: 2.948-21.800) and cytogenetic risk score (p = 0.002, OR 2.113, 95% CI: 1.092-5.007).

CONCLUSIONS

Our study showed that patients with AML are at increased risk of ATE. The risk was increased in patients with cardiovascular comorbidities, previous thrombosis, adverse cytogenetic risk as well as BMI > 30.

Growth factor-free, peptide-functionalized gelatin hydrogel promotes arteriogenesis and attenuates tissue damage in a murine model of critical limb ischemia

Critical limb ischemia (CLI) occurs when blood flow is restricted through the arteries, resulting in ulcers, necrosis, and chronic wounds in the downstream extremities. The development of collateral arterioles (i.e. arteriogenesis), either by remodeling of pre-existing vascular networks or de novo growth of new vessels, can prevent or reverse ischemic damage, but it remains challenging to stimulate collateral arteriole development in a therapeutic context. Here, we show that a gelatin-based hydrogel, devoid of growth factors or encapsulated cells, promotes arteriogenesis and attenuates tissue damage in a murine CLI model. The gelatin hydrogel is functionalized with a peptide derived from the extracellular epitope of Type 1 cadherins. Mechanistically, these "GelCad" hydrogels promote arteriogenesis by recruiting smooth muscle cells to vessel structures in both ex vivo and in vivo assays. In a murine femoral artery ligation model of CLI, delivery of in situ crosslinking GelCad hydrogels was sufficient to restore limb perfusion and maintain tissue health for 14 days, whereas mice treated with gelatin hydrogels had extensive necrosis and autoamputated within 7 days. A small cohort of mice receiving the GelCad hydrogels were aged out to 5 months and exhibited no decline in tissue quality, indicating durability of the collateral arteriole networks. Overall, given the simplicity and off-the-shelf format of the GelCad hydrogel platform, we suggest it could have utility for CLI treatment and potentially other indications that would benefit from arteriole development.

Markers of Restenosis after Percutaneous Transluminal Balloon Angioplasty in Patients with Critical Limb Ischemia

Among cardiovascular diseases, chronic obliterating lesions of the arteries of lower extremities, which are one of the important problems of modern healthcare, are distinguished. In most cases, the cause of damage to the arteries of lower extremities is atherosclerosis. The most severe form is chronic ischemia, characterized by pain at rest and ischemic ulcers, ultimately increasing the risk of limb loss and cardiovascular mortality. Therefore, patients with critical limb ischemia need limb revascularization. Percutaneous transluminal balloon angioplasty is one of the least invasive and safe approaches, with advantages for patients with comorbidities. However, after this procedure, restenosis is still possible. Early detection of changes in the composition of some molecules as markers of restenosis will help screen patients at the risk of restenosis, as well as find ways to apply efforts for further directions of inhibition of this process. The purpose of this review is to provide the most important and up-to-date information on the mechanisms of restenosis development, as well as possible predictors of their occurrence. The information collected in this publication may be useful in predicting outcomes after surgical treatment and will also find new ways for the target implication to the mechanisms of development of restenosis and atherosclerosis.

Periprocedural Outcomes of Rotational Atherectomy-Assisted Balloon Angioplasty in Isolated Atherosclerotic Popliteal Artery Lesions: The ISO-POP Trial

BACKGROUND

Treatment of calcified popliteal artery lesions represents an ongoing challenge for vascular specialists. Biomechanical forces of external compression, torsion and elongation that occur with locomotion in the popliteal segment can lead to stent fractures and occlusions. The aim of our study was to assess the procedural success rate of atherectomy in combination with balloon angioplasty for isolated calcified popliteal artery lesions.

METHODS

Between January 2020 and December 2022, 62 patients with isolated atherosclerotic lesions of the popliteal artery underwent endovascular treatment by use of rotational atherectomy (Phoenix, Philips USA, (subgroup A) or Jetstream, Boston USA, (subgroup B), atherectomy systems) and additional balloon angioplasty in two vascular centers. The primary outcome measures were: 1. periprocedural clinical and technical success (<30% residual stenosis and no need for bailout stenting due to flow-limiting dissection) and 2. postprocedural increase in the ankle brachial index of more than 0.1.

RESULTS

The overall rate of bailout stenting was 4.8%, whereas the procedural success rate was 98.4%. The rate of procedural complications included 3.7% and 5.7% peripheral embolizations in the subgroups A and B, respectively, and no vessel perforations were noted. All embolizations were successfully treated by catheter aspiration or capture in the pre-treatment placed filter system. In addition, 1 (3.7%) pseudoaneurysm in the groin was reported in subgroup A and treated by surgical means. Median ABI of the affected limbs improved from 0.55 (0.2) to 0.70 (0.2) in subgroup A and from 0.50 (0.2) to 0.95 (0.1) in subgroup B (DABI of 0.15 versus 0.45, p < 0.001).

CONCLUSIONS

The combination of rotational atherectomy and balloon angioplasty in the popliteal artery showed reproducible outcomes in 2 centers, with low incidence of complications and low rates of bail-out stenting. These findings may contribute to more liberal use of such devices especially in segments with high risk for stent factures and occlusions.

Predictors of delayed wound healing after simultaneous endovascular treatment and minor forefoot amputation for chronic limb-threatening ischemia with wound infection

OBJECTIVES

To assess wound healing after simultaneous endovascular treatment (EVT) and minor forefoot amputation and identify the predictors of delayed wound healing in patients with chronic limb-threatening ischemia (CLTI) and bacterial infections of the wounds.

METHODS

In this single-center retrospective cohort study, we evaluated 79 consecutive limbs with tissue loss from 73 CLTI patients who underwent simultaneous EVT and minor forefoot amputation between November 2017 and May 2020. To estimate the rate of wound healing after the simultaneous procedure, we used the Kaplan-Meier method. To assess the association between baseline characteristics and delayed wound healing, we used the Cox proportional hazard model.

RESULTS

All patients who underwent the simultaneous procedure had ischemic wounds with bacterial infection. The rate of wound healing at 6 months reached 82%. The median time for wound healing was 76 days. According to multivariable analysis, Lisfranc/Chopart amputation (hazard ratio (HR) 2.46, 95% confidence interval (CI) 1.09-6.60), absence of above-the-knee (ATK) occlusive lesions (HR 1.89, 95% CI 1.04-3.45), and poor below-the-ankle (BTA) runoff (HR 1.77, 95% CI 1.01-3.11) were independent predictors of delayed wound healing.

CONCLUSION

Lisfranc/Chopart amputation, absence of ATK occlusive lesions, and poor BTA runoff were independent predictors of delayed wound healing after simultaneous EVT and minor forefoot amputation in patients with CLTI and bacterial infections of the wound.

Novel Therapeutic Concepts for Complex Femoropopliteal Lesions Using the Jetstream Atherectomy System

INTRODUCTION

The presence of severe arterial calcification is associated with less favorable outcomes in terms of procedural and clinical success as well as higher rates of major adverse limb events. Recent studies incorporating rotational atherectomy for effective preparation of severely calcified lesions demonstrate beneficial procedural outcomes by obtaining maximal luminal gain and improved long-term outcomes.

METHODS

This prospective single-center, observational study includes patients with severely calcified femoropopliteal lesions with chronic limb ischemia Rutherford 1-5 between January 2017 and July 2019, who underwent atherectomy using the Jetstream Atherectomy system, followed by drug-coated balloon angioplasty. Lesion calcification was categorized by the Peripheral Arterial Calcium Scoring System (PACSS), whereas lesion complexity was classified by the Transatlantic Inter-Society Consensus (TASC). Safety and efficacy aspects in terms of vessel injury, thromboembolism, and clinical success were systematically analyzed up to 12 months of follow-up (FU).

RESULTS

In 162 consecutive patients, 210 non-stented and 22 stented lesions were treated. Twelve (7.4%) patients received bail-out stenting. Mean lesion length was 24.2±4.8 cm; 51% were chronic total occlusions (mean occlusion length 18.2±5.1 cm). TASC C lesions were present in 38 patients (23.5%) and TASC D lesions in 124 patients (76.5%). The mean PACCS score was 3.3±0.9. Device success was achieved in 88%; procedural success was noted in 99% of the lesions. Embolic protection device was used in 11.7%. Perforation or dissection occurred in none of the cases. Asymptomatic peripheral embolization was noted in 10 patients (6.2%). Clinical FU at 12 months was available in 157 of 162 patients (96.9%). At 12 month FU, (1) mean Rutherford classification at baseline of 3.7±0.6 significantly dropped to 1.0±0.9 (p<0.05), (2) baseline mean anke-brachial index (ABI) of 0.4±0.1 significantly increased to 0.8±0.2 (p<0.05), (3) 92.6% were free from target lesion revascularization (TLR), (4) 95.1% were free from target vessel revascularization (TVR), and (5) binary restenosis measured by duplex occurred in 22 patients (13.6%). Multivariate analyses showed lesion length as predictive of stent placement (p=0.02), whereas both lesion length (p=0.006) and PACCS score (p=0.02) are predictive of clinical success.

CONCLUSION

Rotational atherectomy in combination with drug-coated balloon (DCB) can be safely performed in long, calcified (non-) occlusive lesions with a relatively low rate of bail-out stenting and favorable clinical mid-term results.

CLINICAL IMPACT

In this prospective, single arm study we demonstrated that combination treatment using rotational atherectomy and DCB is safe and effective in complex and calcified TASC C/D femoropopliteal lesions in patients with claudication or CLTI in a real-world clinical setting. Despite mean lesion length of >20cm and a relatively high rate of chronic total occlusions, the rate of bail-out stenting was surprisingly low (7.4%), whereas the rates of freedom from TLR and TVR were surprisingly high. Thus, our study may encourage vascular specialists to choose an endovascular -first approach even in such complex and calcified femoropopliteal lesions and occlusions in daily clinical practice.

Balloon-Assisted Retrograde Puncture of Distal Vessels in Patients Unsuitable for a Conventional Transpedal Approach

PURPOSE

To describe a novel bailout technique to approach below-the-knee chronic total occlusions after a failed bidirectional recanalization attempt using the plantar loop maneuver in patients who are poor candidates for a retrograde puncture.

TECHNIQUE

After a failure of recanalization of the opposite tibial artery using the plantar loop maneuver, an assisted direct retrograde transpedal approach can be performed regardless of poor vessel caliber or even arterial occlusion. After crossing the plantar arch, a low profile angioplasty balloon is used as a landmark for the pedal puncture and to give guidance for the wire advancement from the new access.

CONCLUSION

A balloon-assisted retrograde transpedal approach may be considered for below-the-knee recanalization after standard plantar loop technique failure in patients who are not candidates for conventional retrograde puncture.

Mesenchymal stem cell-based therapy for non-healing wounds due to chronic limb-threatening ischemia: A review of preclinical and clinical studies

Progressive peripheral arterial disease (PAD) can result in chronic limb-threatening ischemia (CLTI) characterized by clinical complications including rest pain, gangrene and tissue loss. These complications can propagate even more precipitously in the setting of common concomitant diseases in patients with CLTI such as diabetes mellitus (DM). CLTI ulcers are cutaneous, non-healing wounds that persist due to the reduced perfusion and dysfunctional neovascularization associated with severe PAD. Existing therapies for CLTI are primarily limited to anatomic revascularization and medical management of contributing factors such as atherosclerosis and glycemic control. However, many patients fail these treatment strategies and are considered "no-option," thereby requiring extremity amputation, particularly if non-healing wounds become infected or fulminant gangrene develops. Given the high economic burden imposed on patients, decreased quality of life, and poor survival of no-option CLTI patients, regenerative therapies aimed at neovascularization to improve wound healing and limb salvage hold significant promise. Cell-based therapy, specifically utilizing mesenchymal stem/stromal cells (MSCs), is one such regenerative strategy to stimulate therapeutic angiogenesis and tissue regeneration. Although previous reviews have focused primarily on revascularization outcomes after MSC treatments of CLTI with less attention given to their effects on wound healing, here we review advances in pre-clinical and clinical studies related to specific effects of MSC-based therapeutics upon ischemic non-healing wounds associated with CLTI.

Polyester (Dacron®) Grafts in Critical Limb Ischemia Salvage

BACKGROUND

Critical ischemia of the lower limbs refers to the last stages of peripheral arterial disease. It is characterized by resting discomfort or trophic disorders such as ulceration, skin necrosis, or gangrene in the lower limbs. Critical ischemia corresponds to Leriche-Fontaine (LF) stages III-IV and Rutherford stages 4-6. The purpose of this study was to observe the patency and postoperative complications of patients who have had infra-inguinal surgical revascularization and compare the results based on the kind of graft utilized.

METHODS

The present study was designed as an observational retrospective cohort study, including all patients from 2018 to 2019 diagnosed with severe ischemia of the lower limbs who were hospitalized at the Vascular Surgery Clinic of the County Emergency Clinical Hospital of Targu Mures.

RESULTS

Patients with a polytetrafluoroethylene (PTFE) graft had a higher incidence of chronic obstructive pulmonary disease (p = 0.01), stage III LF (70.41% vs. 55.29%), p = 0.03), and a lower incidence of stage IV LF (29.95% vs. 44.71%, p = 0.03). As for complications, the PTFE group showed a lower incidence of bypass thrombosis (29.59% vs. 44.71%; p = 0.03) and graft infection (9.18% vs. 21.18%; p = 0.02), but no statistical significance in the event of bleeding (p = 0.40). Regarding the outcomes, no statistical significance was seen for below-the-knee amputations or death. However, the PTFE group had a lower incidence of above-the-knee amputations (11.22% vs. 24.71%; p = 0.01). At multivariate analysis, the PTFE graft is an independent predictor of primary patency at 6, 12, and 24 months (OR: 2.15, p = 0.02; OR: 1.84, p = 0.04; and OR: 1.89, p = 0.03), as well as a protective factor against bypass thrombosis (OR: 0.52; p = 0.03), graft infection (OR: 0.37; p = 0.02), and above-the-knee amputation (OR: 0.38; p = 0.01).; Conclusions: According to this study's findings, there were minor differences regarding the long-term patency, bypass thrombosis, graft infections, and above-the-knee amputations. In addition, the PTFE graft group had a higher incidence of primary patency at 6, 12, and 24 months, as well as a lower incidence of bypass thrombosis, graft infection, and above-the-knee amputations.

Successful Crossover Bypass Using a Lateral Femoral Circumflex Artery as an Outflow Vessel for Indirect Revascularization in Critical Limb Ischemia: A Case Report

A 78-year-old man presented with severe stage 3 (Fontaine IV, Rutherford 5, W1 I3 FI0) right limb ischemia. Although his artery was completely occluded from below the right external iliac to the popliteal artery, collateral circulation from the right lateral femoral circumflex artery was well developed and supplied the lower extremity arteries. We selected an uncommon crossover bypass strategy with the left common femoral artery to the right lateral femoral circumflex artery to improve lower extremity perfusion via indirect revascularization. Bypass using the lateral femoral circumflex artery as an outflow is an option for patients with major lower extremity artery occlusions.

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.

[Algorithm for balloon angioplasty in patients with critical limb ischemia with diabetic foot syndrome]

Currently, there is no reliable and ideal criterion for assessing the level of tissue viability in critical limb ischemia in patients with diabetic foot syndrome, which does not allow the selection of patients for revascularization.

AIM

The aim is to investigate the microcirculation of the lower extremities before and after balloon angioplasty and to develop an algorithm for its implementation depending on the characteristics of purulent-necrotic complications.

MATERIALS AND METHODS

The study was performed in 67 patients with neuroischemic form of diabetic foot syndrome. 3 groups of research were created: the first group included 18 patients with dry gangrene of one toe, several toes or distal foot; in group II - 35 patients with wet gangrene with signs of purulent arthropathy of the toes, phlegmon of the foot and with chronic wounds on the feet and legs; Group 3 - 14 patients diagnosed with purulent-necrotic complications, which were observed in both the 1st and 2nd groups, where patients refused to perform balloon angioplasty. Such patients underwent conservative treatment of lower extremity ischemia.

RESULTS

It was shown that all patients have low levels of TcpO2- less than 30 mm Hg. The change in the value of TcpO2 during treatment turned out to be interesting: Group I indicator before revascularization was - 15.0±1.31 mm Hg, after the restoration of blood flow for 5- 7 days - 35.53±2.92 mm Hg. after 6 months - 36.67±2.35 mm Hg; Group II before revascularization - 10.35±0.74 mm Hg, for 5-7 days - 25.06±1.13 mm Hg, after 6 months - 34.43±1.97 III group at admission to the hospital - 12.14±0.86 mm Hg, for 5-7 days - 17.14±0.9 mm Hg, after 6 months - 13.71±2.2 mm Hg.

CONCLUSIONS

After revascularization, there is a reperfusion syndrome, the severity of which depends on the number of revascularized vessels of the lower extremity. Balloon angioplasty is one of the priority methods of surgical treatment of limb ischemia with lesions of the shin-foot segment.