Chronic Limb-Threatening Ischemia

Impact of Antimicrobial-Resistant Bacterial and Polymicrobial Infection on Wound Healing After Minor Forefoot Amputation in Chronic Limb-Threatening Ischemia With Infection

OBJECTIVES

This study aimed to evaluate the relationship between bacteriological findings and wound healing after minor amputation in the treatment of chronic limb-threatening ischemia (CLTI) with infection.

METHODS

This single-center retrospective study analyzed 135 consecutive limbs with tissue loss and infection from 120 patients who underwent endovascular therapy (EVT) and minor forefoot amputation for CLTI with wound infection between November 2017 and August 2021. The Kaplan-Meier method was used to assess the rate of wound healing after the procedure. The Cox proportional-hazards model was used to examine the impact of bacteriological findings and baseline characteristics on wound healing.

RESULTS

The wound healing rate at 6 months was 72.6%. In a multivariate analysis, in addition to hemodialysis (hazard ratio [HR]=1.73; p=0.009) and amputation above the metatarsophalangeal (MP) joint (HR=1.81; p=0.006), antimicrobial-resistant bacterial infection (HR=1.80, p=0.004) and polymicrobial infection (H=1.51; p=0.049) were predictors of delayed wound healing.

CONCLUSION

Antimicrobial-resistant bacterial infection, polymicrobial infection, hemodialysis, and amputation above the MP joint were independent predictors of delayed wound healing after EVT and minor forefoot amputation in patients with CLTI and bacterial wound infection.

CLINICAL IMPACT

In this single-center retrospective study, we analyzed 136 consecutive limbs with tissue loss and infection from 120 patients who underwent endovascular therapy and minor forefoot amputation for chronic limb-threatening ischemia (CLTI) with wound infection between November 2017 and August 2021. Our main findings were that antimicrobial-resistant bacterial infection, polymicrobial infection, hemodialysis, and amputation above the metatarsophalangeal joint were independent predictors of delayed wound healing after minor amputation. This is the first report of the association between bacteriological studies and wound healing in CLTI with infection, and will be of great help in the future clinical practice.

Association Between Diagnosis-to-Limb Revascularization Time and Clinical Outcomes in Outpatients With Chronic Limb-Threatening Ischemia: Insights From the CLIPPER Cohort

BACKGROUND

The extent and consequences of ischemia in patients with chronic limb-threatening ischemia (CLTI) may change rapidly, and delays from diagnosis to revascularization may worsen outcomes. We sought to describe the association between time from diagnosis to endovascular lower extremity revascularization (diagnosis-to-limb revascularization [D2L] time) and clinical outcomes in outpatients with CLTI.

METHODS AND RESULTS

In the CLIPPER cohort, comprising patients between 66 and 86 years old diagnosed with CLTI betweeen 2010 and 2019, we used Medicare claims data to identify patients who underwent outpatient endovascular revascularization within 180 days of diagnosis. We described the risk-adjusted association between D2L time and clinical outcomes. Among 1 130 065 patients aged between 66 and 86 years with CLTI, 99 221 (8.8%) underwent outpatient endovascular lower extremity revascularization within 180 days of their CLTI diagnosis. Among patients with D2L time <30 days, there was no association between D2L time and all-cause death or major lower extremity amputation. However, among patients with D2L time >30 days, each additional 10-day increase in D2L time was associated with a 2.5% greater risk of major amputation (hazard ratio, 1.025 [95% CI, 1.014-1.036]). There was no association between D2L time and all-cause death.

CONCLUSIONS

A delay of >30 days from CLTI diagnosis to lower extremity endovascular revascularization was associated with an increased risk of major lower extremity amputation among patients undergoing outpatient endovascular revascularization. Improving systems of care to reduce D2L time could reduce amputations.

Impact of hyperuricemia on 5-year clinical outcomes in patients with critical limb ischemia following percutaneous transluminal angioplasty

BACKGROUND

A growing evidence on the correlation between hyperuricemia and cardiovascular disease (CVD) has been previously reported. However, there have been limited data on the impact of hyperuricemia on long-term clinical outcomes in patients with critical limb ischemia (CLI) who underwent percutaneous transluminal angioplasty (PTA).

METHODS

A total of 425 peripheral artery disease patients who underwent PTA for CLI were enrolled. The patients were divided into the hyperuricemia group (n = 101) and the normal group (n = 324). The primary endpoint was major adverse cerebral and cardiovascular event (MACCE), including death, myocardial infarction, any coronary revascularization, and stroke, up to 5 years. The secondary endpoint was a major adverse limb event (MALE), including any repeated PTA, and target extremity surgery. Inverse probability weighting (IPTW) analysis, derived from the logistic regression model, was performed to adjust for potential confounders.

RESULTS

After IPTW matching analysis, compared to the normal group, the hyperuricemia group was associated with a higher incidence of MACCE (20.7% vs. 13.6%, hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.15-2.38, P  = 0.006) including non-cardiac death (11.7% vs. 6.3%, HR: 1.95, 95% CI: 1.19-3.19, P  = 0.006) and MALE (47.7% vs. 36.0%, HR: 1.62, 95% CI: 1.23-2.13, P  = 0.001) including non-target extremity revascularization (15.0% vs. 6.8%, HR: 2.42, 95% CI: 1.52-3.84, P  < 0.001).

CONCLUSION

In the present study, hyperuricemia was associated with worse clinical outcomes in patients with CLI following PTA during 5-year clinical follow-up. Efficacy of controlling hyperuricemia in improving clinical outcomes should be evaluated in further studies.

Outcomes for Patients With Chronic Limb-Threatening Ischemia After Direct and Indirect Endovascular and Surgical Revascularization: A Meta-Analysis and Systematic Review

PURPOSE

The purpose of this review and meta-analysis is to determine the clinical outcome differences between patients with chronic limb-threatening ischemia who underwent direct versus indirect angiosome revascularization using either the surgical or endovascular approach.

MATERIALS AND METHODS

The data sources used for article selection included PubMed, Embase/Medline, Cochrane reviews, and Web of Science (All studies were in English and included up to September 2023). All articles included were comparative in design, including retrospective, prospective, and randomized controlled trials that compared the clinical outcomes between direct and indirect angiosome-guided revascularization in chronic limb-threatening ischemia. A random-effects model was used to determine the measure of association between direct revascularization and amputation-free survival, wound healing, and overall survival. Publication bias was assessed with both Begg's and Egger's test, and heterogeneity was calculated using an I2.

RESULTS

Data from 9 articles were analyzed and reported in this review. Direct revascularization was associated with improved amputation-free survival (odds ratio [OR]=2.632, confidence interval [CI]: 1.625, 4.265), binary wound healing (OR=2.262, CI: 1.518, 3.372), and overall survival (OR=1.757, CI: 1.176, 2.625). Time until wound healed was not associated with either direct or indirect revascularization (Standard Mean Difference [SMD]=-2.15, p=0.11). There was a low risk of bias across all studies according to the RoB 2.0 tool.

CONCLUSION

Direct revascularization is associated with improved amputation-free survival, overall survival, and wound healing in chronic limb-threatening ischemic patients compared to the indirect approach.

CLINICAL IMPACT

Preservation of the lower extremity is critical for preventing mortality and maintaining independence. The benefit of angiosome-guided revascularization for chronic limb-threatening ischemia remains controversial. The authors of this article aim to review the current literature and compare direct and indirect angiosome-guided intervention for preserving the lower extremity. Current findings suggest direct angiosome-guided intervention reduces amputation rates and improves survival; however, many trials neglect to address the multifactorial approach needed in wound care management.

Quality of Life in Patients With Chronic Limb-Threatening Ischemia Treated With Revascularization

BACKGROUND

In the BEST-CLI trial (Best Endovascular Versus Best Surgical Therapy for Patients With Chronic Limb-Threatening Ischemia), a prespecified secondary objective was to assess the effects of revascularization strategy on health-related quality of life (HRQoL).

METHODS

Patients with chronic limb-threatening ischemia were randomized to surgical bypass (Bypass) or endovascular intervention (Endo) in 2 parallel trials. Cohort 1 included patients with single-segment great saphenous vein; cohort 2 included those lacking suitable single-segment great saphenous vein. HRQoL was assessed over the trial duration using Vascular Quality-of-Life (VascuQoL), European Quality-of-Life-5D (EQ-5D), the Short Form-12 (SF-12) Physical Component Summary (SF-12 PCS), SF-12 Mental Component Summary (SF-12 MCS), Utility Index Score (SF-6D R2), and numeric rating scales of pain. HRQoL was summarized by cohort and compared within and between groups using mixed-model linear regression.

RESULTS

A total of 1193 and 335 patients in cohorts 1 and 2 with a mean follow-up of 2.9 and 2.0 years, respectively, were analyzed. In cohort 1, HRQoL significantly improved from baseline to follow-up for both groups across all measures. For example, mean (SD) VascuQoL scores were 3.0 (1.3) and 3.0 (1.2) for Bypass and Endo at baseline and 4.7 (1.4) and 4.8 (1.5) over follow-up. There were significant group differences favoring Endo when assessed with VascuQoL (difference, -0.14 [95% CI, -0.25 to -0.02]; P=0.02), SF-12 MCS (difference, -1.03 [95% CI, -1.89 to -0.18]; P=0.02), SF-6D R2 (difference, -0.01 [95% CI, -0.02 to -0.001]; P=0.03), numeric rating scale pain at present (difference, 0.26 [95% CI, 0.03 to 0.49]; P=0.03), usual level during previous week (difference, 0.26 [95% CI, 0.04 to 0.48]; P=0.02), and worst level during previous week (difference, 0.29 [95% CI, 0.02 to 0.56]; P=0.04). There was no difference between treatment arms on the basis of EQ-5D (difference, -0.01 [95% CI, -0.03 to 0.004]; P=0.12) or SF-12 PCS (difference, -0.41 [95% CI, -1.2 to 0.37]; P=0.31). In cohort 2, HRQoL also significantly improved from baseline to the end of follow-up for both groups based on all measures, but there were no differences between Bypass and Endo on any measure.

CONCLUSIONS

Among patients with chronic limb-threatening ischemia deemed eligible for either Bypass or Endo, revascularization resulted in significant and clinically meaningful improvements in HRQoL. In patients with an available single-segment great saphenous vein for bypass, but not among those without one, Endo was statistically superior on some HRQoL measures; however, these differences were below the threshold of clinically meaningful difference.

The Double Burden: Deciphering Chronic Limb-Threatening Ischemia in End-Stage Renal Disease

BACKGROUND

Chronic limb-threatening ischemia (CLTI) in patients with end-stage renal disease (ESRD) poses significant challenges in clinical management due to its unique pathology and poor treatment outcomes. This review calls for a tailored classification and risk assessment for these patients to guide better revascularization choices with early minor amputation as a first-line strategy in advanced stages.

METHODS

This review consolidates key findings from recent literature on CLTI in ESRD, focusing on disease mechanisms, treatment options, and patient outcomes. It evaluates the literature to clarify the decision-making process for managing CLTI in ESRD.

RESULTS

CLTI in ESRD patients often results in worse clinical outcomes, such as nonhealing wounds, increased limb loss, and higher mortality rates. While the literature reveals ongoing debates regarding the optimal revascularization method, recent retrospective studies and meta-analyses suggest potential benefits of endovascular treatment (EVT) over open bypass surgery (OB) in reducing mortality and wound complications, with comparable amputation-free survival rates.

CONCLUSIONS

The selection of revascularization methods in ESRD patients with CLTI is complex, necessitating individualized strategies. The importance of early detection and timely intervention is critical to decelerate disease progression and improve revascularization outcomes. There is a shift in these treatment strategies toward less invasive endovascular procedures, acknowledging the limitations these patients face with open revascularization surgeries. Considering early minor amputations after revascularization could prevent worse consequences, reflecting a shift in the approach to managing CLTI in ESRD patients.

Common Criticisms and Rebuttals of the Best Endovascular Versus Best Surgical Therapy in Patients with Chronic Limb-Threatening Ischemia (BEST-CLI) Trial

The Best Endovascular Versus Best Surgical Therapy in Patients With Chronic Limb-Threatening Ischemia trial was a landmark trial which provides high-quality data for the decision-making regarding the treatment of chronic-limb threatening ischemia. Overall, the trial suggests that in patients with adequate greater saphenous vein conduit, bypass surgery should be offered as a first line treatment given superior outcomes. In this article, we outline the common critiques of the trial, followed by responses to provide a deeper understanding of the strengths and limitations of this important trial.

The Management of Aneurysmal Degeneration of Lower Extremity Cryopreserved Saphenous Vein Bypass Grafts

BACKGROUND

The use of cryopreserved saphenous veins (CSVs) for the treatment of lower extremity peripheral arterial disease is an attractive option when there is no available autogenous vein. Prior studies found CSVs are at risk for aneurysmal degeneration requiring reoperation. As the management of these complications and patient outcomes is not well described, the objective of this case series is to describe the open and endovascular management of degenerative CSVs at a tertiary community center.

METHODS

All CSVs implanted for lower extremity bypass at our institution between 2001 and 2021 were retrospectively reviewed. All CSVs with evidence of aneurysmal change were included in this study. CSVs with evidence of active infection were excluded. The decision to intervene was left to the discretion of the operating surgeon. Demographic data, indications for the index operation, and details about subsequent interventions for degenerative CSVs were recorded. Study end points included limb salvage and continued patency. Demographic data, indications for the index operation, and details about subsequent interventions for degenerative CSVs were recorded.

RESULTS

Seventeen bypasses were identified to have aneurysmal degeneration in 13 patients in the absence of infection between 2001 and 2021. Nine of the 13 patients were male, and the average age and body mass index during the index procedure were 72 and 28, respectively. Indications for the index bypass included acute limb ischemia (9), popliteal aneurysm (2), and chronic limb threatening ischemia with Rutherford's class IV (5) and V (1). The mean time between the index procedure and first graft revision due to aneurysmal changes was 4 years. Most of the aneurysms did not occur at the site of anastomosis with 13 occurring in the body of the graft. Thirteen grafts were managed with open surgery and 3 were managed with endovascular techniques. All endovascular repairs were managed via covered stenting. Patients were followed for an average duration of 7 years from the initial bypass and 2 years from their last aneurysmal repair. Limb salvage in this cohort was 87% with 2 limbs requiring amputation, all of whom underwent open reconstruction. The mortality rate in this series was 54% and no patients died due to complications from their graft. Continued patency on Kaplan Meier survival curve analysis was 79% at 6 months, 65% at 1 year, 54% at 3 years, and 27% at 5 years.

CONCLUSIONS

In our experience, aneurysmal degeneration of CSV grafts was mostly managed with standard open surgical techniques, although endovascular therapy also proved acceptable. Limb salvage rates and continued patency of repair at 1 year in this cohort were acceptable. This case series highlights the importance of diligent surveillance for patients with CSVs.

Lower Extremity Bypass for Occlusive Disease: A Brief History

BACKGROUND

This is a narrative review that aims to highlight key advancements that led to the current state of lower extremity bypass surgery. It focuses on key contributors during the last century who have driven the standardization of surgical treatment of peripheral arterial occlusive disease.

METHODS

A narrative review was conducted utilizing available resources in the scientific and historical literature to track landmark achievements in the development of modern lower extremity bypass surgery for occlusive disease, focusing primarily on the last century of advancement.

RESULTS

Several critical conceptual, technological, and technical landmarks were identified as critical components of modern lower extremity bypass surgery. This includes fundamental developments in the techniques of vascular anastomosis led by Carrel and others, a developing understanding of vascular occlusive disease as a localized and segmental process with broad implementation of the techniques of arteriography, and the development of safe thromboendarterectomy aided by the development and utilization of heparin for anticoagulation. These factors led to the first femoral-to-popliteal artery bypass by Jean Kunlin in 1948. From here, advances in vascular prosthetic material pioneered by Voorhees and others, alternative vascular conduits, increasing acceptance of tibial revascularization, and dispelling the myth of diabetic "small vessel" disease broadened revascularization options for patients with complex patterns of occlusive disease and those who have limited conduit availability.

CONCLUSIONS

Modern lower extremity bypass surgery for occlusive disease arose steadily over a course of a century, driven by complex problem-solving in the pathophysiological understanding of atherosclerosis, technical developments in vascular anastomosis and arteriography, and evolution of conduit materials and pharmacologic therapy. Future advancements in bypass surgery are targeted at solving the complex problems of anastomotic intimal hyperplasia, expanding technology for alternative vascular conduits, ongoing optimization of risk factors, and scrutinizing of outcomes to make patient-centered, evidence-based decisions regarding revascularization strategy.

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.

End of Life Care for Unplanned Vascular Admissions

BACKGROUND

Unplanned vascular admissions have a high mortality. Previous studies have indicated that end of life care (EoLC) among this group of patients is low but there exist limited data on EoLC in the United Kingdom. The aim of this study was to evaluate the quality and predictors of EoLC for unplanned vascular admissions to a tertiary center in the United Kingdom.

METHODS

This was a retrospective single-center cohort study of unplanned vascular surgery admissions from August 1, 2019 to January 22, 2020. Data on patient demographics, markers of quality of palliative care, mortality, and cause of death of unplanned admission to the vascular surgery department were collected from hospital and general practitioner records and evaluated against EoLC to evaluate predictors and efficacy of EoLC. Quality of palliative care markers included documentation of preferred place of death and care priorities, time spent in hospital and the intensive care unit toward the end of life, and realization of documented care objectives. EoLC input was defined as a dedicated palliative care consultation (PCC) by a palliative care professional, medical doctor, surgeon, or advanced care practitioner. We also conducted a subgroup analysis of patients within this group with chronic limb-threatening ischemia (CLTI), diabetic foot, and ruptured aortic aneurysms, as all patients in this group should be offered EoLC according to international guidelines.

RESULTS

One-hundred and fifty patients were included. Median age at presentation was 70.5 years, and the cohort consisted of mostly men (72%). CLTI (31%) was the most common reason for admission. Surgical intervention was carried out in 60% of patients. Two-year mortality was 36%, and pneumonia (22%) was the most common cause of death. Seven percent of patients received PCC, which occurred a median of 10 days before death. Only a minority of patients had preferred place of care/death (14%), care priorities (37%), and family involvement during advance care planning (17%) documented in their notes; 29% of patients had Recommended Summary Plan for Emergency Care and Treatment forms in place. A diagnosis of left ventricular systolic dysfunction, chronic kidney disease, and increasing age predicted Recommended Summary Plan for Emergency Care and Treatment form completion. Patients with PCC were more likely to have advance care planning, but this did not translate into improvements in the other markers of quality of palliative and, consequently, EoLC.

CONCLUSIONS

EoLC was insufficient and of low quality despite a high mortality in this group. Clinical guidelines and pathways are needed to ensure these patients are considered for EoLC and those with CLTI, diabetic foot sepsis or ruptured abdominal aortic aneurysms are offered it by default. Further research is needed to help identify vascular patients who would benefit from EoLC earlier to improve quality at end of life.

Systemic immunosuppression does not affect revascularization outcomes in patients with chronic limb-threatening ischemia

OBJECTIVE

Many patients with chronic limb-threatening ischemia (CLTI) have additional comorbidities requiring systemic immunosuppression. Few studies have analyzed whether these medications may inhibit graft integration and effectiveness, or conversely, whether they may prevent inflammation and/or restenosis. Therefore, our study aim was to examine the effect of systemic immunosuppression vs no immunosuppression on outcomes after any first-time lower extremity revascularization for CLTI.

METHODS

We identified all patients undergoing first-time infrainguinal bypass graft (BPG) or percutaneous transluminal angioplasty with or without stenting (PTA/S) for CLTI at our institution between 2005 and 2014. Patients were stratified by procedure type and immunosuppression status, defined as ≥6 weeks of any systemic immunosuppression therapy ongoing at the time of intervention. Immunosuppression vs nonimmunosuppression were the primary comparison groups in our analyses. Primary outcomes included perioperative complications, reintervention, primary patency, and limb salvage, with Kaplan-Meier and Cox proportional hazard models used for univariate and multivariate analyses, respectively.

RESULTS

Among 1312 patients, 667 (51%) underwent BPG and 651 (49%) underwent PTA/S, of whom 65 (10%) and 95 (15%) were on systemic immunosuppression therapy, respectively. Whether assessing BPG or PTA/S patients, there were no differences noted in perioperative outcomes, including perioperative mortality, myocardial infarction, stroke, hematoma, or surgical site infection (P > .05). For BPG patients, Kaplan-Meier analysis and log-rank testing demonstrated no significant difference in three-year reintervention (37% vs 33% [control]; P = .75), major amputation (27% vs 15%; P = .64), or primary patency (72% vs 66%; P = .35) rates. Multivariate analysis via Cox regression confirmed these findings (immunosuppression hazard ratio [HR] for reintervention, 0.95; 95% CI, 0.56-1.60; P = .85; for major amputation, HR, 1.44; 95% CI, 0.70-2.96; P = .32; and for primary patency. HR, 0.97; 95% CI, 0.69-1.38; P = .88). For PTA/S patients, univariate analysis revealed similar rates of reintervention (37% vs 39% [control]; P = .57) and primary patency (59% vs 63%; P = .21); however, immunosuppressed patients had higher rates of major amputation (23% vs 12%; P = .01). After using Cox regression to adjust for baseline demographics, as well as operative and anatomic characteristics, immunosuppression was not associated with any differences in reintervention (HR, 0.75; 95% CI, 0.49-1.16; P = .20), major amputation (HR, 1.46; 95% CI, 0.81-2.62; P = .20), or primary patency (HR, 0.84; 95% CI, 0.59-1.19; P = .32). Sensitivity analyses for the differences in makeup of immunosuppression regimens (steroids vs other classes) did not alter the interpretation of any findings in either BPG or PTA/S cohorts.

CONCLUSIONS

Our findings demonstrate that patients with chronic systemic immunosuppression, as compared with those who are not immunosuppressed, does not have a significant effect on late outcomes after lower extremity revascularization, as measured by primary patency, reintervention, or major amputation.

Endovascular Treatment of TASC C and D Femoropopliteal Arterial Disease With Heparin-Bonded Covered Stents: The Impact of Distal Run-Off Vessels

INTRODUCTION

In the last 2 decades, several studies in the literature evaluated the possible role of covered stents in the treatment of TransAtlantic Inter-Society Consensus (TASC) C and D femoropopliteal lesions but, despite the encouraging results, the employment of these devices was never included in clinical guidelines. The aim of this study is to evaluate the role of the technical aspects in patients with TASC C or D lesions that were treated with the GORE VIABAHN endoprosthesis and to elaborate a computerized method to objectively estimate the post-stent run-off and predict stent-graft failure.

MATERIALS AND METHODS

In this monocentric retrospective study, we collected the patients who were treated in our department from December 2014 to May 2021. Inclusion criteria comprised: (1) patients who underwent endovascular treatment of a TASC C or D femoropopliteal lesions using one or more heparin-bonded covered stent(s) and (2) clinical follow-up >2 years. Exclusion criteria were clinical follow-up <2 years or missing. An in-house computerized analysis to estimate the post-stent run-off, CEVERO (Computerized Estimation of VEssel Run-Off), was elaborated.

RESULTS

Sixty-six patients were enrolled in the study. Eleven patients had a TASC type C lesion, and 55 patients presented a type D lesion. The median follow-up time was 2.6 years. Twenty-nine patients (43.9%) experienced a major adverse limb event. Primary patency after 6, 12 and 24 months was 74.2%, 60.6%, and 57.6%; primary-assisted patency was 78.8%, 65.2%, and 59.1%. The presence of <2 run-off vessels (p<0.001) was correlated with stent-graft failure. The CEVERO analysis demonstrated an accuracy of 90.0% in predicting stent-graft failure.

CONCLUSIONS

The treatment of TASC C and D femoropopliteal lesions remains technically challenging. Our study supported the hypothesis that run-off is the most critical factor in determining the outcome of the procedure and that concomitant angioplasty of the tibial vessels might improve the patency of the covered stent. The CEVERO analysis could permit a real-time, objective estimation of the distal run-off using conventional angiographic images, and it might be employed as a tool in the intraprocedural decision-making process, but its clinical applicability should be evaluated on external validation cohorts.

CLINICAL IMPACT

The endovascular treatment of TASC C and D femoropopliteal lesions is technically challenging and run-off seems to be the most critical factor in determining the outcome. Concurrent angioplasty of the tibial vessels can create adequate run-off to avoid stent failure. The CEVERO analysis is a computerized estimation of run-off that might be a useful tool in the decision-making process.

Epigenetic Regulation of Angiogenesis in Peripheral Artery Disease

Peripheral arterial disease (PAD) represents a global health concern with a rising prevalence attributed to factors such as obesity, diabetes, aging, and smoking. Among patients with PAD, chronic limb-threatening ischemia (CLTI) is the most severe manifestation, associated with substantial morbidity and mortality. While revascularization remains the primary therapy for CLTI, not all patients are candidates for such interventions, highlighting the need for alternative approaches. Impaired angiogenesis, the growth of new blood vessels, is a central feature of PAD, and despite decades of research, effective clinical treatments remain elusive. Epigenetics, the study of heritable changes in gene expression, has gained prominence in understanding PAD pathogenesis. Here, we explore the role of epigenetic regulation in angiogenesis within the context of PAD, with a focus on long non-coding RNAs and fibroblast-endothelial cell transdifferentiation. Additionally, we discuss the interplay between metabolic control and epigenetic regulation, providing insights into potential novel therapeutic avenues for improving PAD treatments. This review aims to offer a concise update on the application of epigenetics in angiogenesis and PAD research, inspiring further investigations in this promising field.

Skeletal muscle regeneration failure in ischemic-damaged limbs is associated with pro-inflammatory macrophages and premature differentiation of satellite cells

BACKGROUND

Chronic limb-threatening ischemia (CLTI), a severe manifestation of peripheral arterial disease (PAD), is associated with a 1-year limb amputation rate of approximately 15-20% and substantial mortality. A key feature of CLTI is the compromised regenerative ability of skeletal muscle; however, the mechanisms responsible for this impairment are not yet fully understood. In this study, we aim to delineate pathological changes at both the cellular and transcriptomic levels, as well as in cell-cell signaling pathways, associated with compromised muscle regeneration in limb ischemia in both human tissue samples and murine models of CLTI.

METHODS

We performed single-cell transcriptome analysis of ischemic and non-ischemic muscle from the same CLTI patients and from a murine model of CLTI. In both datasets, we analyzed gene expression changes in macrophage and muscle satellite cell (MuSC) populations as well as differential cell-cell signaling interactions and differentiation trajectories.

RESULTS

Single-cell transcriptomic profiling and immunofluorescence analysis of CLTI patient skeletal muscle demonstrated that ischemic-damaged tissue displays a pro-inflammatory macrophage signature. Comparable results were observed in a murine CLTI model. Moreover, integrated analyses of both human and murine datasets revealed premature differentiation of MuSCs to be a key feature of failed muscle regeneration in the ischemic limb. Furthermore, in silico inferences of intercellular communication and in vitro assays highlight the importance of macrophage-MuSC signaling in ischemia induced muscle injuries.

CONCLUSIONS

Collectively, our research provides the first single-cell transcriptome atlases of skeletal muscle from CLTI patients and a murine CLTI model, emphasizing the crucial role of macrophages and inflammation in regulating muscle regeneration in CLTI through interactions with MuSCs.

Endovascular Interventions for Peripheral Artery Disease: A Contemporary Review

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Dynamic Perfusion Computed Tomography for the Assessment of Concomitant Coronary Artery Disease in Patients with a History of Percutaneous Transluminal Angioplasty for Chronic Limb-Threatening Ischemia-A Pilot Study

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is associated with high rates of long-term cardiovascular mortality. Exercise stress testing to detect obstructive coronary artery disease (CAD) can be difficult in this subset of patients due to inability to undergo exercise testing, presence of balanced ischemia and severe coronary artery calcification (CAC).

AIM

To test the feasibility of regadenoson stress dynamic perfusion computed tomography (DPCT) in CLTI patients.

METHODS

Between 2018 and 2023, coronary computed tomography angiography (CTA) and, in the case of a calcium score higher than 400, DPCT, were performed in 25 CLTI patients with a history of endovascular revascularization.

RESULTS

Of the 25 patients, 19 had a calcium score higher than 400, requiring DPCT image acquisition. Obstructive CAD could be ruled out in 10 of the 25 patients. Of the 15 CTA/DPCT+ patients, 13 proceeded to coronary angiography (CAG). Revascularization was necessary in all 13 patients. In these 13 patients, vessel-based sensitivity and specificity of coronary CTA/DPCT as compared to invasive evaluation was 75%, respectively. At follow-up (27 ± 21 months) there was no statistically significant difference in all-cause mortality between CTA/DPCT- positive and -negative patients (p = 0.065).

CONCLUSIONS

Despite a high prevalence of severe CAC, coronary CTA complemented by DPCT may be a feasible method to detect obstructive and functionally significant CAD in CLTI patients.

Combined Revascularization and Free Flap Reconstruction for Chronic Limb-Threatening Ischemia: A Systematic Review and Meta-Analysis

BACKGROUND

 Combined revascularization and free flap reconstruction is one treatment method for chronic limb-threatening ischemia (CLTI) with complex wounds. The purpose of this systematic review and meta-analysis was to investigate the characteristics of this combined procedure and to assess postoperative outcomes.

METHODS

 A systematic search was performed across PubMed, Scopus, and the Web of Science for studies between January 2000 and February 2022. A random-effects meta-analysis for postoperative outcome was conducted.

RESULTS

 Fifteen articles encompassing 1,176 patients with 1,194 free flaps were ultimately included in the qualitative and quantitative assessment. Our meta-analysis showed the following complication rates for short-term postoperative outcomes: 37% (95% confidence interval [CI], 18-53%; I 2 = 74%) for reoperation, 13% (95% CI, 2-24%; I 2 = 0%) for vascular thrombosis, 9% (95% CI, 0-17%; I 2 = 0%) for total flap failure, 8% (95% CI, 0-17%; I 2 = 0%) for partial flap failure, 4% (95% CI, 0-10%; I 2 = 0%) for amputation, and 3% (95% CI, 0-9%; I 2 = 0%) for 30-day mortality. The 1-, 3-, and 5-year limb salvage rates were 86% (95% CI, 78-92%), 81% (95% CI, 68-88%), and 71% (95% CI, 53-83%), respectively. The 1-, 3-, and 5-year patient survival rates were 93% (95% CI, 90-96%), 92% (95% CI, 77-97%), and 75% (95% CI, 50-88%), respectively.

CONCLUSION

 Combined revascularization and free flap reconstruction for CLTI with complex wounds was clearly effective for the long-term outcomes. However, this combined procedure should be considered on the assumption that the reoperation rate is high and that flap-related complications rate may be higher than lower extremity reconstruction of other etiologies.

Systematic Review and Meta-analysis of Clinical Outcomes After Endovascular Treatment in Patients With Femoropopliteal Lesions Greater Than 150 mm

OBJECTIVE

Indications for endovascular treatment of femoropopliteal (FP) lesions have steadily increased over the past decade. Accordingly, the number of devices has also increased but the choice of the best endovascular treatment remains to be defined. The aim of this meta-analysis was to summarize all studies investigating endovascular treatment of FP lesions greater than 150 mm from 2010 to 2021.

METHODS

Articles were searched using PubMed, Scopus, and Cochrane. Included studies were randomized controlled trials (RCTs), cohort studies, and case series (prospective and retrospective) that evaluated any endovascular procedure in patients with long FP lesions classified TASC (Trans-Atlantic Inter-Society Consensus document II on management of peripheral arterial disease) C and/or D, and a mean length >150 mm, primary outcome had to be the 1-year primary patency. Overall estimate of primary patency, secondary patency, and freedom from target lesion revascularization (TLR) at 1 year depending on the different devices were investigated. The meta-analysis was conducted following the requirements of the MOOSE (Meta-analysis of Observational Studies in Epidemiology) checklist.

RESULTS

Forty-four papers comprising 4847 patients and 5282 treated limbs were included. Mean lesions length ranged from 150.5 to 330 mm. The pooled 1-year primary and secondary patencies, and freedom from TLR rates were 0.71 (95% CI: 0.67-0.74), 0.87 (95% CI: 0.83-0.91), and 0.79 (95% CI: 0.74-0.84), respectively. Primary permeability at 1 year were 0.68 (95% CI: 0.62-0.73), 0.67 (95% CI: 0.60-0.74), 0.74 (95% CI: 0.64-0.84), and 0.83 (95% CI: 0.78-0.88) for bare metal stents, covered stents (CSs), drug-eluting stents, and drug-coated balloons (DCBs), respectively. Lesions treated with DCB had the highest 1-year primary patency rate.

CONCLUSIONS

At 1-year, endovascular procedures for FP lesions greater than 150 mm obtain satisfactory results. High primary patency rates were obtained with drug-coated devices, while CSs obtained less favorable results. Randomized studies comparing different devices in the treatment of long FP lesions remain necessary to determine the most optimal approach for the management of these patients.

CLINICAL IMPACT

This paper highlights on the one hand the satisfactory results of endovascular treatment on complex femoropopliteal lesions formerly reserved for conventional surgery. On the other hand, among the available devices, paclitaxel-eluting devices seem to show superior results which should make them recommended as first-line treatment.

Alternative access for peripheral vascular interventions

Percutaneous endovascular interventions for advanced lower extremity peripheral arterial disease are becoming increasingly used, often as first-line treatment of chronic limb threatening ischemia. Advancements in endovascular techniques have provided safe and effective alternative revascularization options, especially for high-risk surgical patients. Although the classic transfemoral approach results in high technical success and patency rates, an estimated 20% of lesions remain challenging to access via an antegrade approach. As such, alternative access sites are important in the endovascular armamentarium for the management of chronic limb threatening ischemia. The goal of this review is to discuss alternative access sites, specifically the transradial, transpopliteal, and transpedal approaches, in addition to transbrachial and transaxillary access, and their outcomes in peripheral arterial disease and limb salvage.

Arterial leg ulcers-Bacterial patterns, antimicrobial resistance and clinical characteristics, a retrospective single-centre cohort, 2012-2021

OBJECTIVE

Severe wound infections in patients with peripheral artery disease (PAD) are common, potentially life- and limb-threatening, and difficult to treat. Evidence on patients with infected leg ulcers in PAD is scarce. This study aims to provide insight into the microbiological patterns and antimicrobial resistance (AMR) of specific pathogens in patients with arterial leg ulcers.

METHODS AND DESIGN

In this retrospective, consecutive, single-centre study 16,553 patients underwent an endovascular revascularization procedure between 2012 and 2021. Of these, 1,142 patients had PAD Rutherford category 5 or 6 with infected leg ulcers. Logistic regression was used to identify risk factors for Staphylococcus aureus-associated infections.

RESULTS

A total of 3,431 bacterial isolates were detected, of which 2,335 (68.1%) bacterial isolates were gram-positive and 1,096 (31.9%) were gram-negative species. The most prevalent bacteria were S. aureus (18.6%), Enterococcus faecalis (9.1%) and S. epidermidis (7.8%). Pseudomonas aeruginosa (5.6%), Proteus mirabilis (3.7%) and Escherichia coli (3.4%). The resistance of S. aureus isolates to clindamycin was 11.0%. Resistance to oxacillin was rare (1.5%). P. aeruginosa is frequently resistant to ciprofloxacin (14.4%) whilst intrinsically resistant to trimethoprim/sulfamethoxazole. P. mirabilis and E. coli were frequently resistant to both ciprofloxacin (7.3; 20.7%) and trimethoprim/sulfamethoxazole (24.6; 22.6%), respectively. Resistance to amoxicillin/clavulanic acid was high among E. coli isolates (36.8%). Multi-drug resistance (MDR) was rare among S. aureus and P. aeruginosa isolates. In contrast, the proportion of MDR was high in E. coli isolates. End-stage renal disease was independently positively associated with S. aureus identification (p = .042).

CONCLUSION

S. aureus was the most common pathogen in arterial leg ulcers with end-stage renal disease being an independent risk factor. Clindamycin resistance was common, making empirical therapy likely to fail. Isolated E. coli species had a high proportion of MDR.

Antithrombotic drugs for cardiovascular risk reduction in patients with lower limb peripheral arterial disease: protocol for a systematic review and network meta-analysis of randomised controlled trials

INTRODUCTION

The optimal antithrombotic regimen to reduce the risk of vascular events in patients with peripheral arterial disease (PAD) is contentious. This systematic review and network meta-analysis (NMA) aims to define the relative efficacy and risks of previously investigated antithrombotic medication regimens in preventing major cardiovascular events, vascular limb events and mortality in patients with PAD.

METHODS AND ANALYSIS

A peer-reviewed, systematic search will be executed in English on Medline, Embase, Cochrane (CENTRAL), Web of Science and Google Scholar databases in late 2022. The WHO International Clinical Trials Registry platform will also be searched for ongoing trials. Abstracts will be screened independently by two researchers for randomised controlled trials meeting the review criteria. All associated publications including the study protocol will be sought and evaluated together against prespecified inclusion/exclusion criteria. Two researchers will extract the data into a prepiloted extraction form. Risk-of-bias assessments will be performed using the Cochrane 'Risk-of-Bias V.2' criteria by individuals with domain expertise. All differences will be resolved by consensus or a third individual for ties.Included trials will be summarised. An NMA will be performed, subject to checks of assumptions. Both primary and secondary outcomes will be analysed on a whole network basis. Pairwise comparisons and league tables will be produced. Prespecified subgroup analyses will include sex, ethnicity, disease status, conservative versus interventional management and key comorbidities. The findings will be evaluated using the Grading of Recommendation Assessment, Development and Evaluation, informed by patient and public involvement work.

ETHICS AND DISSEMINATION

This is a systematic review of data in the public domain and does not require ethical approval. Dissemination will include presentations to key vascular and patient organisations, publication in a peer-reviewed journal and an open-access repository of the study data.

PROSPERO REGISTRATION NUMBER

CRD42023389262.

Endothelial cell direct reprogramming: Past, present, and future

Ischemic cardiovascular disease still remains as a leading cause of morbidity and mortality despite various medical, surgical, and interventional therapy. As such, cell therapy has emerged as an attractive option because it tackles underlying problem of the diseases by inducing neovascularization in ischemic tissue. After overall failure of adult stem or progenitor cells, studies attempted to generate endothelial cells (ECs) from pluripotent stem cells (PSCs). While endothelial cells (ECs) differentiated from PSCs successfully induced vascular regeneration, differentiating volatility and tumorigenic potential is a concern for their clinical applications. Alternatively, direct reprogramming strategies employ lineage-specific factors to change cell fate without achieving pluripotency. ECs have been successfully reprogrammed via ectopic expression of transcription factors (TFs) from endothelial lineage. The reprogrammed ECs induced neovascularization in vitro and in vivo and thus demonstrated their therapeutic value in animal models of vascular insufficiency. Methods of delivering reprogramming factors include lentiviral or retroviral vectors and more clinically relevant, non-integrative adenoviral and episomal vectors. Most studies made use of fibroblast as a source cell for reprogramming, but reprogrammability of other clinically relevant source cell types has to be evaluated. Specific mechanisms and small molecules that are involved in the aforementioned processes tackles challenges associated with direct reprogramming efficiency and maintenance of reprogrammed EC characteristics. After all, this review provides summary of past and contemporary methods of direct endothelial reprogramming and discusses the future direction to overcome these challenges to acquire clinically applicable reprogrammed ECs.

Focus on the Prevention of Acute Limb Ischemia: Centrality of the General Practitioner from the Point of View of the Internist

The thrombotic mechanism, being common to peripheral arterial disease (PAD), acute myocardial infarction (AMI), and stroke, is responsible for the highest number of deaths in the western world. However, while much has been done for the prevention, early diagnosis, therapy of AMI and stroke, the same cannot be said for PAD, which is a negative prognostic indicator for cardiovascular death. Acute limb ischemia (ALI) and chronic limb ischemia (CLI) are the most severe manifestations of PAD. They both are defined by the presence of PAD, rest pain, gangrene, or ulceration and we consider ALI if symptoms last less than 2 weeks and CLI if they last more than 2 weeks. The most frequent causes are certainly atherosclerotic and embolic mechanisms and, to a lesser extent, traumatic or surgical mechanisms. From a pathophysiological point of view, atherosclerotic, thromboembolic, inflammatory mechanisms are implicated. ALI is a medical emergency that puts both limb and the patient's life at risk. In patients over age 80 undergoing surgery, mortality remains high reaching approximately 40% as well as amputation approximately 11%. The purpose of this paper is to summarize the scientific evidence on the possibilities of primary and secondary prevention of ALI and to raise awareness among doctors involved in the management of ALI, in particular by describing the central role of the general practitioner.

The Effect of Chronic and End Stage Renal Disease on Long-term Outcomes after Infrainguinal Bypass

OBJECTIVES

Patients undergoing infrainguinal bypass for chronic limb threatening ischemia (CLTI) with renal dysfunction are at an increased risk for perioperative and long-term morbidity and mortality. Our goal was to examine perioperative and 3-year outcomes after lower extremity bypass for CLTI stratified by kidney function.

METHODS

A retrospective, single-center analysis of lower extremity bypass for CLTI was performed between 2008 and 2019. Kidney function was categorized as normal (estimated glomerular filtration rate (eGFR) ≥60ml/min/1.73m²), chronic kidney disease (CKD) (eGFR15-59ml/min/1.73m²), and end stage renal disease (ESRD) (eGFR<15ml/min/1.73m²). Kaplan-Meier and multivariable analysis were performed.

RESULTS

There were 221 infrainguinal bypasses performed for CLTI. Patients were classified by renal function as normal (59.7%), CKD (24.4%), and ESRD (15.8%). Average age was 66 years and 65% were male. Overall, 77% had tissue loss with 9%, 45%, 24%, and 22% being Wound, Ischemia, and foot Infection (WIfI) stages 1-4, respectively. The majority (58%) of bypass targets were infrapopliteal and 58% used ipsilateral greater saphenous vein. The 90-day mortality and readmission rates were 2.7% and 49.8%, respectively. ESRD, compared to CKD and normal renal function, respectively, had the highest 90-day mortality (11.4% vs. 1.9% vs. .8%, P=.002) and 90-day readmission (69% vs. 55% vs. 43%, P=.017). On multivariable analysis, ESRD, but not CKD, was associated with higher 90-day mortality (OR 16.9, 95% CI 1.83-156.6, P=.013) and 90-day readmission (OR 3.02, 95% CI 1.2-7.58, P=.019). Kaplan Meier 3-year analysis showed no difference between groups for primary patency or major amputation, however ESRD, compared to CKD and normal renal function, respectively, had worse primary-assisted patency (60% vs. 76% vs. 84%, P=.03) and survival (72% vs. 96% vs. 94%, P=.001). On multivariable analysis, ESRD and CKD were not associated with 3-year primary patency loss/death, but ESRD was associated with higher primary-assisted patency loss (HR 2.61, 95% CI 1.23-5.53, P=.012). ESRD and CKD were not associated with 3-year major amputation/death. ESRD was associated with higher 3-year mortality (HR 4.95, 95% CI 1.52-16.2, P=.008) while CKD was not.

CONCLUSION

ESRD, but not CKD, was associated with higher perioperative and long-term mortality after lower extremity bypass for CLTI. Although ESRD was associated with lower long-term primary-assisted patency, there were no differences in loss of primary patency or major amputation.

Pro-inflammatory macrophages impair skeletal muscle regeneration in ischemic-damaged limbs by inducing precocious differentiation of satellite cells

Chronic limb-threatening ischemia (CLTI), representing the end-stage of peripheral arterial disease (PAD), is associated with a one-year limb amputation rate of ∼15-20% and significant mortality. A key characteristic of CLTI is the failure of the innate regenerative capacity of skeletal muscle, though the underlying mechanisms remain unclear. Here, single-cell transcriptome analysis of ischemic and non-ischemic muscle from the same CLTI patients demonstrated that ischemic-damaged tissue is enriched with pro-inflammatory macrophages. Comparable results were also observed in a murine CLTI model. Importantly, integrated analyses of both human and murine data revealed premature differentiation of muscle satellite cells (MuSCs) in damaged tissue and indications of defects in intercellular signaling communication between MuSCs and their inflammatory niche. Collectively, our research provides the first single-cell transcriptome atlases of skeletal muscle from CLTI patients and murine models, emphasizing the crucial role of macrophages and inflammation in regulating muscle regeneration in CLTI through interactions with MuSCs.

Sclerotherapy of lower limb veins: Indications, contraindications and treatment strategies to prevent complications - A consensus document of the International Union of Phlebology-2023

BACKGROUND

Sclerotherapy is a non-invasive procedure commonly used to treat superficial venous disease, vascular malformations and other ectatic vascular lesions. While extremely rare, sclerotherapy may be complicated by serious adverse events.

OBJECTIVES

To categorise contraindications to sclerotherapy based on the available scientific evidence.

METHODS

An international, multi-disciplinary panel of phlebologists reviewed the available scientific evidence and developed consensus where evidence was lacking or limited.

RESULTS

Absolute Contraindications to sclerotherapy where the risk of harm would outweigh any benefits include known hypersensitivity to sclerosing agents; acute venous thromboembolism (VTE); severe neurological or cardiac adverse events complicating a previous sclerotherapy treatment; severe acute systemic illness or infection; and critical limb ischaemia. Relative Contraindications to sclerotherapy where the potential benefits of the proposed treatment would outweigh the risk of harm or the risks may be mitigated by other measures include pregnancy, postpartum and breastfeeding; hypercoagulable states with risk of VTE; risk of neurological adverse events; risk of cardiac adverse events and poorly controlled chronic systemic illness. Conditions and circumstances where Warnings and Precautions should be considered before proceeding with sclerotherapy include risk of cutaneous necrosis or cosmetic complications such as pigmentation and telangiectatic matting; intake of medications such as the oral contraceptive and other exogenous oestrogens, disulfiram and minocycline; and psychosocial factors and psychiatric comorbidities that may increase the risk of adverse events or compromise optimal treatment outcomes.

CONCLUSIONS

Sclerotherapy can achieve safe clinical outcomes provided that (1) patient-related risk factors and in particular all material risks are (1a) adequately identified and the risk benefit ratio is clearly and openly discussed with treatment candidates within a reasonable timeframe prior to the actual procedure; (1b) when an individual is not a suitable candidate for the proposed intervention, conservative treatment options including the option of 'no intervention as a treatment option' are discussed; (1c) complex cases are referred for treatment in controlled and standardised settings and by practitioners with more expertise in the field; (1d) only suitable individuals with no absolute contraindications or those with relative contraindications where the benefits outweigh the risks are offered intervention; (1e) if proceeding with intervention, appropriate prophylactic measures and other risk-mitigating strategies are adopted and appropriate follow-up is organised; and (2) procedure-related risk factors are minimised by ensuring the treating physicians (2a) have adequate training in general phlebology with additional training in duplex ultrasound, procedural phlebology and in particular sclerotherapy; (2b) maintain their knowledge and competency over time and (2c) review and optimise their treatment strategies and techniques on a regular basis to keep up with the ongoing progress in medical technology and contemporary scientific evidence.

Injury Precipitating Tissue Loss and Time to Referral to a Vascular Center in Patients with Chronic Limb-Threatening Ischemia

AIM

This study aimed to report injury precipitating tissue loss and to provide updated information on the time from tissue loss occurrence to referral to a vascular center for patients who developed chronic limb-threatening ischemia (CLTI) in Japan.

METHODS

We examined 450 patients who developed CLTI with tissue loss and were registered in a multicenter prospective study between October 2017 and June 2020. They were referred to the participating vascular centers for revascularization. Information on the injury precipitating tissue loss and time to referral was collected at registration. The severity of tissue loss was evaluated using the Wound, Ischemia, and foot Infection classification.

RESULTS

Injury precipitating tissue loss was absent in 52.0% (95% confidence interval, 47.3%-56.6%) of the patients. The absence was associated with lower albumin levels and preserved pressure sensation. Although the time to referral was significantly shorter in cases without a history of prereferral revascularization, 16.8% (12.8%-20.7%) of the patients were referred to the vascular centers more than 3 months after tissue loss occurrence. Time to referral, but not the lack of a clear precipitant for tissue loss, was significantly associated with the severity of tissue loss.

CONCLUSION

A clear precipitant for tissue loss was often lacking, particularly in patients with low albumin levels and preserved pressure sensation. Delayed referral to a vascular center is still common.

A Prospective Analysis of the SVS WIfI Classification System to Stratify Immediate and 1-Year Patient Outcomes

The purpose of this study was to prospectively enroll patients that presented to the emergency department with a lower extremity infection, stratify risk and record outcomes. Risk stratification was performed based on the Society of Vascular Surgery Wound, foot Infection, and Ischemia (WIfI) classification system. This study aimed to establish the efficacy and validity of this classification in predicting patient outcomes during immediate hospitalization and throughout a 1 year follow up. A total of 152 patients were enrolled in the study and of these, 116 met the inclusion criteria and had at least 1 year of follow up for analysis. Each patient was assigned a WIfI score based on wound, ischemia, and foot infection severity according to the classification guidelines. Patient demographics as well as all podiatric and vascular procedures were recorded. The major end points of the study were rates of proximal amputation, time to wound healing, surgical procedures, surgical dehiscence, readmission rates, and mortality. A difference in rates of healing (p = .04), surgical dehiscence (p < .01), and 1 year mortality (p = .01) with increasing WIfI stage as well as across the individual component scores was noted. This analysis further supports the application of the WIfI classification system early during patient care to stratify risk and identify the need for early intervention and a multispecialty team approach to potentially improve outcomes in the severe multicomorbid patient.

Alleviating iatrogenic effects of paclitaxel via anti-inflammatory treatment

Background

Paclitaxel is touted as an essential medicine due to its extensive use as a chemotherapeutic for various cancers and an antiproliferative agent for restenosis. Due to recent concerns related to long-term mortality, paclitaxel (PTX)-based endovascular therapy is now surrounded by controversies.

Objective

Examine the inflammatory mediators driven by the systemic administration of PTX and explore the means to suppress these effects.

Methods

RNAseq analysis, cell and mouse models.

Results

RNAseq analysis of primary human endothelial cells (ECs) treated with PTX demonstrated transcriptional perturbations of a set of pro-inflammatory mediators, including monocyte chemoattractant protein-1 (MCP-1) and CD137, which were validated in EC lysates. These perturbations were abrogated with dexamethasone, a prototypic anti-inflammatory compound. The media of ECs pre-treated with PTX showed a significant increase in MCP-1 levels, which were reverted to baseline levels with DEX treatment. A group of mice harvested at different time points after PTX injection were analyzed for immediate and delayed effects of PTX. A 3-fold increase in MCP-1 was noted in blood and aortic ECs after 12 hours of PTX treatment. Similar changes in CD137 and downstream mediators such as tissue factor, VCAM-1 and E-selectin were noted in aortic ECs.

Conclusions

Our study shows that systemic PTX exposure upregulates atherothrombotic markers, and co-delivery of DEX can subdue the untoward toxic effects. Long-term studies are needed to probe the mechanisms driving systemic complications of PTX-based therapies and evaluate the clinical potential of DEX to mitigate risk.

Surgery or Endovascular Therapy for Chronic Limb-Threatening Ischemia

BACKGROUND

Patients with chronic limb-threatening ischemia (CLTI) require revascularization to improve limb perfusion and thereby limit the risk of amputation. It is uncertain whether an initial strategy of endovascular therapy or surgical revascularization for CLTI is superior for improving limb outcomes.

METHODS

In this international, randomized trial, we enrolled 1830 patients with CLTI and infrainguinal peripheral artery disease in two parallel-cohort trials. Patients who had a single segment of great saphenous vein that could be used for surgery were assigned to cohort 1. Patients who needed an alternative bypass conduit were assigned to cohort 2. The primary outcome was a composite of a major adverse limb event - which was defined as amputation above the ankle or a major limb reintervention (a new bypass graft or graft revision, thrombectomy, or thrombolysis) - or death from any cause.

RESULTS

In cohort 1, after a median follow-up of 2.7 years, a primary-outcome event occurred in 302 of 709 patients (42.6%) in the surgical group and in 408 of 711 patients (57.4%) in the endovascular group (hazard ratio, 0.68; 95% confidence interval [CI], 0.59 to 0.79; P<0.001). In cohort 2, a primary-outcome event occurred in 83 of 194 patients (42.8%) in the surgical group and in 95 of 199 patients (47.7%) in the endovascular group (hazard ratio, 0.79; 95% CI, 0.58 to 1.06; P = 0.12) after a median follow-up of 1.6 years. The incidence of adverse events was similar in the two groups in the two cohorts.

CONCLUSIONS

Among patients with CLTI who had an adequate great saphenous vein for surgical revascularization (cohort 1), the incidence of a major adverse limb event or death was significantly lower in the surgical group than in the endovascular group. Among the patients who lacked an adequate saphenous vein conduit (cohort 2), the outcomes in the two groups were similar. (Funded by the National Heart, Lung, and Blood Institute; BEST-CLI ClinicalTrials.gov number, NCT02060630.).

Cost of Treatment of Neuroischemic Ulcers of the Lower Extremity in Patients with Peripheral Artery Disease in the United States

BACKGROUND

We evaluated the cost of treating neuroischemic ulcers of the lower extremity in patients with peripheral artery disease by using medical and hospital claims records submitted for reimbursement to payers (private insurance, Medicare, Medicaid).

METHODS

Adjudicated claims and remittance data on claims that include submitted charges, line items paid by insurers directly to providers and patient payments of copays, deductibles and co-insurance were used. Eligible patients from a commercial database containing more than 60% of US patients with health insurance were analyzed. Patient selection, performed using International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes, yielded a study population of 42,837 unique anonymized patients.

RESULTS

Using the metric of "submitted charges" to overcome differences in levels of reimbursement across insurance payers and Medicare/Medicaid, we identified 34,348 patients with ulcers with an average treatment cost of $94,100 per patient ($41,800 annualized) The costliest ulcer subtype was nonpressure ulcer of the heel/midfoot among 13,184 patients with $121,400 per patient ($53,900 annualized), 29% higher than across all ulcer types. The subset of 22,281 ulcer patients who also had a surgical procedure incurred costs of $121,000 per patient ($53,800 annualized). The costliest surgical codes were complications of vascular prosthetic devices, implants, grafts among 6444 patients with $146,900 per patient ($65,300 annualized). The combination of most expensive ulcer and most expensive surgery yielded a cohort of 2355 patients with the highest average cost of $177,400 per patient ($78,800 annualized).

CONCLUSIONS

The resource burden for management of neuroischemic ulcers of the lower extremity in patients with peripheral artery disease is substantial. Mitigating this burden may help reduce significant resource utilization.

Photoacoustic imaging to monitor outcomes during hyperbaric oxygen therapy: validation in a small cohort and case study in a bilateral chronic ischemic wound

Hyperbaric oxygen therapy (HBO2) is a common therapeutic modality that drives oxygen into hypoxic tissue to promote healing. Here, ten patients undergoing HBO2 underwent PA oximetry of the left radial artery and forearm pre- and post-HBO2; this cohort validated the use of PA imaging in HBO2. There was a significant increase in radial artery oxygenation after HBO2 (p = 0.002) in the validation cohort. We also include a case study: a non-diabetic male in his 50s (HB 010) presenting with bilateral ischemic and gangrenous wounds. HB 010 showed higher perfusion and oxygen saturation on the right foot than the left after HBO2 which correlated with independent surgical observations. Imaging assisted with limb salvage treatment. Hence, this work shows that PA imaging can measure changes in arterial oxygen saturation due to HBO2; it can also produce 3D maps of tissue oxygenation and evaluate response to therapy during HBO2.

A Review of Illness Perceptions in Chronic Limb-Threatening Ischemia: Current Knowledge Gaps and a Framework for Future Studies

OBJECTIVES

To review illness perceptions (IP) in chronic limb-threatening ischemia (CLTI) patients undergoing revascularisation (open surgical or endovascular), major lower extremity amputation, or conservative management.

METHODS

MEDLINE, EMBASE, PsycINFO, CINAHL, WOS, and Scopus databases were searched from inception to August 20^th, 2021 for studies evaluating IP in CLTI according to Leventhal's Common-Sense Model (CSM). Since only one study was identified, a post-hoc secondary literature search of MEDLINE was performed for reviews of IP in cardiovascular disease and diabetes to identify potential learning points for future research. All studies underwent narrative synthesis guided by tabulated data.

RESULTS

One study and seven reviews were included from the primary and secondary literature searches, respectively. Timeline and controllability were the main aspects of IP that predict prosthetic use in CLTI patients, more so at six months than one month. Other reviews in cardiovascular disease and diabetes identified important targets for future research: (i) factors that affect IP and whether IP can be used as an outcome measure, (ii) relationship between IP and clinician-reported and patient-reported outcomes, and (iii) methods to educate and change maladaptive IP. The importance of using valid and reliable measures of IP that encompass all components of Leventhal's' CSM was stressed.

CONCLUSIONS

Knowledge of IP in CLTI patients is severely limited in contrast to other fields in cardiovascular disease and diabetes. This review helps to close this gap by raising awareness of IP and its importance within the vascular surgical community, and by providing a framework for future studies.

A 41-Year-Old Woman with a Cold Foot

A 41-Year-Old Woman with a Cold FootA 41-year-old woman presented for evaluation of a painful and cold right foot. How do you approach the evaluation, and what is the diagnosis?

Urinary Fatty Acid Binding Protein 3 Has Prognostic Value in Peripheral Artery Disease

Background

Despite its significant association with limb loss and death, peripheral artery disease (PAD) remains underdiagnosed and undertreated. The current accepted gold-standard for PAD screening, the ankle brachial index (ABI), is limited by operator dependence, erroneous interpretation, and unreliability in patients with diabetes. Fatty acid binding protein 3 (FABP3) is an intracellular protein that becomes released into circulation and excreted into urine following skeletal muscle injury. We examined the prognostic ability of urinary FABP3 (uFABP3) in predicting adverse PAD-related events.

Methods

In this prospective case-control study, urine samples were collected from patients with PAD (n = 142) and without PAD (n = 72). The cohort was followed for 2 years. uFABP3 was normalized to urinary creatinine (uCr) (uFABP3/uCr). The primary outcome was major adverse limb event (MALE; composite of vascular intervention [open or endovascular] or major limb amputation). The secondary outcome was worsening PAD status (drop in ABI≥0.15). Cox regression analyses with multivariable adjustment for baseline demographic and clinical variables were performed to assess the prognostic value of uFABP3/uCr with regards to predicting MALE and worsening PAD status.

Results

Patients with PAD had significantly higher median [IQR] uFABP3/uCr levels (3.46 [2.45–6.90] vs. 2.61 [1.98–4.62], p = 0.001). MALE and worsening PAD status were observed in 21 (10%) and 28 (14%) patients, respectively. uFABP3/uCr predicted MALE and worsening PAD status with adjusted hazard ratios (HR) of 1.28 (1.16–1.41, p = 0.001) and 1.16 (1.02–1.27, p = 0.021), respectively. Patients with high uFABP3/uCr had a lower 2-year freedom from MALE (86 vs. 96%, p = 0.047) and worsening PAD status (78 vs. 99%, p = 0.001). There was good discriminatory ability for uFABP3/uCr in predicting the primary outcome of MALE, with an area under the receiver operating characteristics curve (AUROC) of 0.78.

Conclusions

Measuring uFABP3/uCr levels in patients with PAD can help identify those at high risk of adverse PAD-related events. This study highlights the prognostic value of uFABP3 in risk-stratifying individuals for further diagnostic vascular evaluation or aggressive medical management.

Impact of frailty on all-cause mortality or major amputation in patients with lower extremity peripheral artery disease: A meta-analysis

BACKGROUND

Frailty has been increasingly identified as a risk factor of adverse outcomes in vascular disease. However, its impact on the survival and amputation in patients with lower extremity peripheral artery disease (PAD) remains controversial. This meta-analysis aimed to examine the value of frailty in predicting all-cause mortality or major amputation in patients with lower extremity PAD.

METHODS

PubMed, Embase, Web of Sciences, and Scopus databases (up to April 7, 2022) were comprehensively searched to identify relevant studies that investigated the association between frailty and all-cause mortality or major amputation in patients with lower extremity PAD. The impact of frailty on adverse outcomes was summarized by pooling the fully adjusted hazard ratio (HR) with 95% confidence intervals (CI) using a random effect (DerSimonian-Laird) model.

RESULTS

Seven studies reporting on eight articles that involved 122,892 patients were included. The prevalence of frailty ranged from 42% to 80% based on the frailty tool used. Meta-analysis showed that frailty was associated with an increased risk of 30-day all-cause mortality (HR 2.11; 95% CI 1.41-3.15; I² =47.6%, p = 0.148, Tau-squared=0.058) and long-term all-cause mortality (HR 1.86; 95% CI 1.25-2.76; I² =76.1%, p = 0.002, Tau-squared=0.118). However, no clear association was observed between frailty and major amputation (HR 1.07; 95% CI 0.83-1.36; I² =23.0%, p = 0.273, Tau-squared=0.019).

CONCLUSION

Frailty independently predicts short and long-term all-cause mortality but not major amputation in patients with lower extremity PAD. Frailty status may play an important role in risk stratification of lower extremity PAD.

Effects of Lower Limb Revascularization on the Microcirculation of the Foot: A Retrospective Cohort Study

Background: Current assessment standards in chronic limb-threatening ischemia (CLTI) focus on macrovascular function while neglecting the microcirculation. Multispectral near-infrared spectroscopy (NIRS) provides hemodynamic characteristics of the microcirculation (i.e., capillaries) and may be a powerful tool for monitoring CLTI and preventing extremity loss. The aims of this study were to (1) investigate the effects of lower limb revascularization on the microcirculation and (2) determine if macrovascular and microvascular assessments correlate. Methods: An observational, retrospective cohort study of 38 endovascular interventions in 30 CLTI subjects was analyzed pre- and post-intervention for arterial Doppler acceleration times (AcT; macrovascular) and NIRS metrics (microvascular). Pre-intervention ankle-brachial index (ABI) was also analyzed. Results: AcT significantly decreased (p = 0.009) while oxyhemoglobin (HbO) significantly increased (p < 0.04) after endovascular intervention, indicating treatment efficacy. However, macrovascular measurements (ABI, AcT) and NIRS metrics of oxygenation and perfusion did not correlate (p > 0.06, r2 < 0.15, n = 23) indicating that macro- and microvascular assessment are not congruent. Conclusion: These findings suggest that macrovascular and microvascular assessments can determine interventional efficacy in their corresponding vasculature. Their lack of correlation, however, suggests the need for simultaneous assessment as independent use may cause diagnostic information to be missed.

Association of Chronic Kidney Disease with perioperative outcomes following acute lower limb revascularization

Background

There is a paucity of data examining the impact of advancing chronic kidney disease stages on outcomes following revascularization for acute limb ischemia. The present study examined the association of chronic kidney disease with in-hospital mortality, amputation, and resource utilization following revascularization for acute limb ischemia using a nationally representative cohort.

Methods

The 2016–2018 National Inpatient Sample was queried to identify all adult hospitalizations with lower extremity acute limb ischemia requiring surgical and/or endovascular interventions. Patients were grouped according to the presence of chronic kidney disease and its severity: no chronic kidney disease, chronic kidney disease 1–3 (chronic kidney disease stages 1 through 3), chronic kidney disease 4–5 (chronic kidney disease stages 4 through 5), and end-stage renal disease. Multivariable logistic and linear models were used to evaluate association of chronic kidney disease stage with outcomes of interest.

Results

Of an estimated 82,610 patients meeting study criteria, 14.8% had chronic kidney disease (chronic kidney disease 1–3: 63.4%, chronic kidney disease 4–5: 12.1%, end-stage renal disease: 24.5%). Compared to those with chronic kidney disease, chronic kidney disease patients were on average older, were more frequently female, and had a higher median Elixhauser Comorbidity Index. Increasing severity of chronic kidney disease was associated with a stepwise increase in unadjusted mortality rates (4.7% in no chronic kidney disease to 12.6% in end-stage renal disease, P < .001). Following risk adjustment, only end-stage renal disease was associated with increased odds of mortality (adjusted odds ratio 3.10, 95% confidence interval 2.28–4.22) and limb amputation (adjusted odds ratio 1.99, 95% confidence interval 1.59–2.48) compared to patients with no chronic kidney disease. Similarly, advancing chronic kidney disease stage conferred increased odds of prolonged length of stay and greater hospitalization costs.

Conclusion

Advanced renal dysfunction demonstrated inferior perioperative outcomes and greater health care expenditures in the study population. These findings imply that quality improvement efforts in acute limb ischemia revascularization should target patients with chronic kidney disease 4–5 and end-stage renal disease.

Implantation of Hypoxia-Induced Mesenchymal Stem Cell Advances Therapeutic Angiogenesis

Hypoxia preconditioning enhances the paracrine abilities of mesenchymal stem cells (MSCs) for vascular regeneration and tissue healing. Implantation of hypoxia-induced mesenchymal stem cells (hi-MSCs) may further improve limb perfusion in a murine model of hindlimb ischemia. This study is aimed at determining whether implantation of hi-MSCs is an effective modality for improving outcomes of treatment of ischemic artery diseases. We evaluated the effects of human bone marrow-derived MSC implantation on limb blood flow in an ischemic hindlimb model. hi-MSCs were prepared by cell culture under 1% oxygen for 24 hours prior to implantation. A total of 1 × 10⁵ MSCs and hi-MSCs and phosphate-buffered saline (PBS) were intramuscularly implanted into ischemic muscles at 36 hours after surgery. Restoration of blood flow and muscle perfusion was evaluated by laser Doppler perfusion imaging. Blood perfusion recovery, enhanced vessel densities, and improvement of function of the ischemia limb were significantly greater in the hi-MSC group than in the MSC or PBS group. Immunochemistry revealed that hi-MSCs had higher expression levels of hypoxia-inducible factor-1 alpha and vascular endothelial growth factor A than those in MSCs. In addition, an endothelial cell-inducing medium showed high expression levels of vascular endothelial growth factor, platelet endothelial cell adhesion molecule-1, and von Willebrand factor in hi-MSCs compared to those in MSCs. These findings suggest that pretreatment of MSCs with a hypoxia condition and implantation of hi-MSCs advances neovascularization capability with enhanced therapeutic angiogenic effects in a murine hindlimb ischemia model.

Generation and Application of Directly Reprogrammed Endothelial Cells

Direct cell reprogramming refers to the conversion of cell identity, without transition through an induced pluripotent state. Owing to the ability to directly reprogram into numerous cell types, this reprogramming strategy has received enormous attention for regenerative therapy. Particularly, direct reprogramming into functional endothelial cells, which are crucial for neovascularization and vascular regeneration, holds promising therapeutic potential for treating patients with ischemic cardiovascular diseases. This review provides a summary of the-state-of-art in direct endothelial reprograming strategies and highlights their potential applications. It also discusses key questions and challenges that will help guiding future research and development of this emerging area.

Cell-based therapy has emerged as a promising option for treating advanced ischemic cardiovascular disease by inducing vascular regeneration. However, clinical trials with adult cells turned out disappointing in general. As a newer approach, direct reprogramming has emerged to efficiently generate endothelial cells (ECs), which can promote neovascularization and vascular regeneration. This review provides recent updates on the direct endothelial reprogramming. In general, directly reprogrammed ECs can be generated by two approaches: one by transitioning through a plastic intermediate state and the other in a one-step transition without any intermediate states toward pluripotency. Moreover, the methods to deliver reprogramming factors and chemicals for the fate conversion are highlighted. Next, the therapeutic effects of the directly reprogrammed ECs on animal models are reviewed in detail. Other applications using directly reprogrammed ECs, such as tissue engineering and disease modeling, are also discussed. Lastly, the remaining questions and foremost challenges are addressed.

Tryptophan metabolites suppress Wnt pathway and promote adverse limb events in CKD patients

Chronic kidney disease (CKD) imposes a strong and independent risk for peripheral artery disease (PAD). While solutes retained in CKD patients (uremic solutes) inflict vascular damage, their role in PAD remains elusive. Here, we show that the dietary tryptophan-derived uremic solutes including indoxyl sulfate (IS) and kynurenine (Kyn) at concentrations corresponding to those in CKD patients suppress β-catenin in several cell types, including microvascular endothelial cells (ECs), inhibiting Wnt activity and proangiogenic Wnt targets in ECs. Mechanistic probing revealed that these uremic solutes downregulated β-catenin in a manner dependent on serine 33 in its degron motif and through the aryl hydrocarbon receptor (AHR). Hindlimb ischemia in adenine-induced CKD and IS solute–specific mouse models showed diminished β-catenin and VEGF-A in the capillaries and reduced capillary density, which correlated inversely with blood levels of IS and Kyn and AHR activity in ECs. An AHR inhibitor treatment normalized postischemic angiogenic response in CKD mice to a non-CKD level. In a prospective cohort of PAD patients, plasma levels of tryptophan metabolites and plasma’s AHR-inducing activity in ECs significantly increased the risk of future adverse limb events. This work uncovers the tryptophan metabolite/AHR/β-catenin axis as a mediator of microvascular rarefaction in CKD patients and demonstrates its targetability for PAD in CKD models.

Skin Perfusion Pressure Predicts Early Wound Healing After Endovascular Therapy in Chronic Limb Threatening Ischaemia

OBJECTIVE

Skin perfusion pressure (SPP) has been proposed as a method to predict wound healing in chronic limb threatening ischaemia (CLTI). However, studies regarding the impact of SPP before and after endovascular therapy (EVT) on wound healing are limited. This study sought to evaluate the predictive value of SPP for early wound healing in CLTI treated by EVT.

METHODS

Between January 2018 and June 2020, 236 limbs (172 patients) with CLTI that underwent SPP measurement before and after EVT were included. SPP was measured before and 24 - 48 hours after the procedure. Early wound healing was defined as the achievement of complete epithelisation of all wounds without major amputation within three months of EVT.

RESULTS

Early wound healing was achieved in 145 (61.4%) limbs after EVT. Baseline SPP (44.1 ± 21.0 mmHg vs. 33.5 ± 21.7 mmHg; p < .001) and post-procedural SPP (61.8 ± 18.5 mmHg vs. 37.4 ± 19.9 mmHg; p < .001) were significantly higher in the wound healing (+) group than in the wound non-healing (-) group. The area under the receiver operating characteristics curve for early wound healing was 0.82 for post-procedural SPP with a cutoff value of 50 mmHg (sensitivity 74.5%, specificity 78.0%). The early wound healing rate was significantly higher with a post-procedural SPP ≥ 50 mmHg compared with a SPP < 50 mmHg (84.4% vs. 35.0%; p < .001).

CONCLUSION

Post-procedural SPP with a cutoff value of 50 mmHg was capable of predicting early wound healing after EVT in CLTI.

Participation in a Chronic Limb Threatening Ischemia Randomized Trial Is Inversely Correlated With Regional Amputation Rate in Limb Threatening Ischemia Patients

OBJECTIVE

The National Health Service demonstrated that regions of the United Kingdom with the highest number of patients enrolled in research studies had the lowest risk-adjusted mortality when patients were admitted to the hospital. Our goal was to investigate if this correlation was evident for patients with chronic limb threatening ischemia (CLI) treated in the United States (US). Accordingly, we examined correlations among sites participating in the Best Endovascular versus best Surgical Therapy in patients with Critical (BEST-CLI) trial, a multicenter, National Institute of Health-sponsored, international randomized controlled trial (RCT) comparing revascularization strategies in patients with CLI, and regional rates of major amputation from CLI.

METHODS

We measured regional participation in the BEST-CLI trial by evaluating trial participation and enrollment rosters. To determine regional rates of lower limb amputation, we queried the Medicare database (2007-2016) for patients with concurrent peripheral arterial disease (PAD) and diabetes, then assessed how many had lower extremity amputations. Correlation of regional amputation rates with distribution of BEST-CLI sites in four US geographical regions was calculated using Pearson's correlation coefficients. Simple regression equations were used to calculate the significance of these correlation coefficients.

RESULTS

Of 9,231,909 CLI patients, 342,406 underwent amputation in the Medicare dataset. Amputation rates per 1000 CLI patients differed by region (South 40.42, Midwest 40.12, West 34.81, Northeast 31.14). There were 116 US vascular centers, selected by volume and expertise that participated in BEST-CLI with the following distribution: South (n = 30, 26%), Midwest (n = 26, 22%), West (n = 29, 25%), and Northeast (n = 31, 27%). There was a negative correlation between the number of amputations per 1000 for Medicare CLI patients with diabetes and PAD and the number of BEST-CLI sites in the region which trended toward significance (Pearson R= -0.61, P = 0.39).

CONCLUSIONS

Amputation rate among Medicare CLI patients is inversely correlated with US BEST-CLI site distribution. Higher participation in clinical research, especially within large RCTs, may be a marker of optimal PAD management.

Low-intensity pulsed ultrasound decreases major amputation in patients with critical limb ischemia: 5-year follow-up study

Various therapeutic strategies for angiogenesis are performed to improve symptoms in patients with critical limb ischemia (CLI). Pre-clinical studies have shown that low-intensity pulsed ultrasound (LIPUS) exposure induces angiogenesis. LIPUS may be a new stratergy for treatment of CLI. The purpose of this pilot trial was to evaluate outcomes in patients with CLI who were treated with LIPUS. Fourteen patients with CLI, who were not candidates for angioplasty or surgical revascularization, were enrolled in this study. Historical control data were obtained from the Hiroshima University PAD database. The primary endpoints were major amputation and death. The outcomes were compared in 16 lower limbs of the 14 patients with CLI who were treated with LIPUS and in 14 lower limbs of 14 patients with CLI as historical controls. All patients were followed for after 5 years after treatment with LIPUS. The mean duration of LIPUS exposure in the LIPUS group was 381± 283 days. During the 5-year follow-up periods, there were 3 major amputations and 7 deaths in the LIPUS group and there were 14 major amputations and 7 deaths in the historical control group. The overall amputation-free survival rate was significantly higher in patients who were treated with LIPUS than in historical controls. There was no significant difference between overall mortality-free survival rates in the LIPUS group and historical control group. LIPUS is a noninvasive option for therapeutic angiogenesis with the potential to reduce the incidence of major amputations in patients with CLI.

The Impact of Chronic Kidney Disease on Peripheral Artery Disease and Peripheral Revascularization

Chronic kidney disease (CKD) is a clinical condition characterized by high morbidity and mortality. Globally, CKD is also increasing in prevalence and incidence. The two principal kidney measures namely estimated glomerular filtration rate (eGFR) and albuminuria have been found to be predictors of renal and cardiovascular (CV) endpoints including peripheral artery disease (PAD). The prevalence of PAD was increased in CKD patients and, particularly, in patients with more severe CKD stages. Despite the fact that revascularization strategies are suitable in CKD patients in similar fashion to non-CKD patients, few CKD patients underwent these procedures. In fact, if it is true that revascularization improves prognosis in PAD patients irrespective of baseline eGFR, it was also demonstrated that CKD patients, who underwent revascularization, were at higher risk for amputations, mortality, re-intervention and perioperative complications. With the present review article, we have examined the association between CKD, PAD and peripheral revascularization highlighting data about epidemiology, pathophysiologic mechanisms, and results from previous observational and intervention studies. We have also examined the future perspectives and challenges of research around the association between CKD and PAD.

Drug-Coated Balloon versus Bare Nitinol Stent in Femoropopliteal Artery: 12 Months Outcome from a Single Center in China

OBJECT

The study sought to compare the safety and effectiveness of drug-coated balloon (DCB) with bare nitinol stent in patients with complex femoropopliteal(FP) lesions in real-world practice.

METHODS

Patients with symptomatic (Rutherford stage 2 to 5) femoropopliteal lesions who underwent DCB or bare nitinol stent implantation at the Department of Cardiovascular Surgery of China-Japan Friendship Hospital from June 2016 to September 2017 were included. Demographics, angiographic and procedural variables were included. Freedom from target lesion revascularization (TLR), primary patency and major adverse events were obtained from follow-up results at 3,6 and12 months. Descriptive analysis was performed on all variables.

RESULTS

A total of 90 eligible patients were enrolled, which included 51 DCB subjects (mean age, 63.1 ± 13.2 years; 76.5% male) with 55 lesions and 39 nitinol stent subjects (mean age, 66.5 ± 10.5 years; 61.5% male) with 42 lesions. Significant higher primary patency was observed in the DCB group compared with the stent group (74.5% vs. 52.4%; log-rank test P = 0.018; HR 0.335, 95%CI 0.124-0.903, P = 0.031). The rates of freedom from TLR (f-TLR) were 78.2% and 59.5% (log-rank test P = 0.032) for the DCB group and the stent group, respectively, at 12 months. CD-TLR rates were 18.2% vs. 38.1% with a P-value of 0.023. Female sex (HR 6.122, 95%CI 1.880-19.934, P = 0.003), lesion length over 20 cm (HR 5.514, 95%CI 2.312-13.148, P < 0.001) and renal insufficiency (HR 2.609, 95%CI 1.087-6.260, P = 0.032) were suggested as independent risk factors of reducing primary patency. There were no significant differences in major adverse events between the 2 groups.

CONCLUSION

The result above demonstrates that DCB treatment has higher primary patency and lower TLR at 12 months than nitinol stent. These data confirm the safety and effectiveness of the DCB for patients with complex femoropopliteal lesions.

Cause of Death Among Patients With Peripheral Artery Disease

Background:

Peripheral artery disease is common and associated with high mortality. There are limited data detailing causes of death among patients with peripheral artery disease.

Methods:

EUCLID (Examining Use of Ticagrelor in Peripheral Artery Disease) was a randomized clinical trial that assigned patients with peripheral artery disease to clopidogrel or ticagrelor. We describe the causes of death in EUCLID using mortality end points adjudicated through a clinical events classification process. The association between baseline factors and cardiovascular death was evaluated by Cox proportional hazards modeling. The competing risk of noncardiovascular death was assessed by the cumulative incidence function for cardiovascular death and the Fine and Gray method to ascertain the association between baseline characteristics and cardiovascular mortality.

Results:

A total of 1263 out of 13 885 (9.1%) patients died (median follow-up: 30 months). There were 706 patients (55.9%) with a cardiovascular cause of death and 522 (41.3%) with a noncardiovascular cause of death. The most common cause of cardiovascular death was sudden cardiac death (20.1%); while myocardial infarction (5.2%) and ischemic stroke (3.2%) were uncommon. The most common causes of noncardiovascular death were malignancies (17.9%) and infections (11.9%). The factor most associated with a higher risk of cardiovascular death was age per 5 year increase (HR, 1.26 [95% CI, 1.20–1.32]). Female sex was associated with a lower risk of cardiovascular death (HR, 0.68 [95% CI, 0.56–0.82]). To evaluate the effect of noncardiovascular death as a competing risk, we superimposed the cumulative incidence function curve with the Kaplan-Meier curve. These curves closely approximated each other. After accounting for the competing risk of noncardiovascular death, the magnitude and direction of the factors associated with cardiovascular death were minimally changed.

Conclusions:

Among patients with symptomatic peripheral artery disease, noncardiovascular causes of death reflected a high proportion (40%) of deaths. Accounting for noncardiovascular deaths as a competing risk, there was not a significant change in the risk estimation for cardiovascular death.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01732822.