Improved amputation-free survival in unreconstructable critical limb ischemia and its implications for clinical trial design and quality measurement

Multidisciplinary Limb-Salvage Care is Associated with Decreased Mortality Without Increasing Revascularization In Major Amputations

OBJECTIVE

Development and implementation of a multidisciplinary limb-salvage program has been shown to improve amputation free survival (AFS) and reduce need for major amputations; however, the impact of this approach on patients who eventually progress to major amputation is unclear. The goal of this study is to assess the effect of a multidisciplinary limb-salvage team (MLT) on revascularization rates prior to major amputation and outcomes following major amputation in patients in an urban setting.

METHODS

Patients in a single health-care system who underwent major lower extremity amputations between January 1st 2014 and December 31st 2021 were identified using Current Procedural Terminology (CPT) codes within our electronic medical records. Patient demographic data, comorbidities, pre-amputation revascularization, limb-salvage procedures, and one year mortality were collected by chart review. Chi-square test, likelihood ratio tests, Mann-Whitney U test and student's t-test were used to compare patient variables and outcomes between pre- and post- launch of a multidisciplinary limb-salvage team. Univariate and multivariate logistic regression analysis were used to assess patient characteristics associated with 30-day pre-amputation revascularization and one year mortality.

RESULTS

471 patients underwent major lower extremity amputations during the study period: 52% below knee amputations (BKA), 47% above knee amputations (AKA) and 1% through knee disarticulation (TKD). Comparing pre-amputation revascularization procedures stratified by involvement of a multi-disciplinary limb care team, there was no significant difference in 30-day revascularization rate (30.2% vs. 30.6%, p=0.93). Pre-amputation revascularization rates within 90 days (45.1%% vs. 45.8%, p=0.87) and one year (56.1 vs. 51.9%, p=0.84) remained similar between groups as well. There was a statistically significant increase in 30-day pre-amputation debridement/minor amputation (25.9% vs. 44.9%, p<0.001) after MLT implementation; this significant increase was also shown within 90 days and one year prior to amputation. One-year mortality rate in AKA (28% vs. 18.7%, p=0.15) was not significantly different after MLT implementation but one-year mortality in all major amputations (26.4% vs. 14.3%, p=0.002) and BKA (24.8% vs. 12.2%, p=0.013) group were significantly different after MLT implementation. Patient characteristics associated with 30-day pre-amputation revascularization included hypertension (OR 2.1, 95% CI 1.2-3.8), smoking status (OR 1.7, CI 1.1-2.6), and requiring debridement/minor amputation within 30 days prior to major amputation (OR 2.3, 95% CI 1.4-3.6). Patients older than 65 (OR 3.2, 95% CI 1.6-6.3) with end stage renal disease (ESRD) (OR 2.7, 95% CI 1.5-4.9) were associated with higher risk for one year mortality. Implementation of limb salvage program was associated with improved one-year post-amputation mortality overall (OR 0.54, 95% CI 0.31-0.96).

CONCLUSION

For patients with chronic limb threatening ischemia (CLTI) who eventually progressed to require major lower extremity amputations, implementation of a limb salvage program did not change pre-amputation revascularization practice. However, it was associated with significantly improved one-year post-amputation mortality. Our findings further support the global vascular guidelines, demonstrating the benefit of limb salvage services in patients with major amputations.

Comparison of outcomes of percutaneous deep venous arterialization in multiple practice settings

OBJECTIVE

We compared the efficacy of percutaneous deep venous arterialization (pDVA) in patients with no-option chronic limb-threatening ischemia in the hospital vs in office-based laboratory (OBL) settings.

METHODS

A retrospective chart review was performed of all patients who underwent pDVA using off-the-shelf devices from January 2018 to March 2023 in a hospital and an OBL. We identified 73 eligible patients, 41 from a hospital setting (59% male; median age, 72 years; interquartile range, 18 years) and 32 from an OBL setting (59% males; 67 years; interquartile range, 16 years). All eligible patients were deemed to have no-option critical limb ischemia, had at least one patent proximal tibial artery available for the creation of an arteriovenous anastomosis, and were classified as having Rutherford classification IV or higher peripheral arterial disease. Patients were ineligible if classified as Rutherford classification III or lower, had active infection, did not have at least one appropriate venous target, and/or had rapidly progressing wounds requiring immediate major amputation. The primary outcome was major amputation-free survival (AFS). Secondary outcomes included technical success, limb salvage, survival, primary patency, reintervention rate, adverse events, and partial and complete wound healing. Outcomes were evaluated using Kaplan-Meier method, log-rank, and two-stage procedure tests.

RESULTS

Technical success was achieved in 70 patients (96%) with 1 hospital (2.4%) and 2 OBL (6.3%) patients lost to follow-up. Major AFS estimates at 6 months, 1 year, and 2 years were 51.4%, 40.4%, and 30.2% in the hospital group and 69.4%, 54.0%, and 49.5% in the OBL group, respectively. Partial wound healing estimates at 6 months, 1 year, and 2 years were 27.5%, 71.7%, and 81.2% in the hospital group and 62.7% at all time points in the OBL group. Complete wound healing estimates at 6 months, 1 year, and 2 years were 6.7%, 33.3%, and 33.3% in the hospital group and 5.3%, 37.7%, and 41.6% in the OBL group, respectively. There was no significant difference in major AFS (P = .13), limb salvage (P = .07), survival (P = .69), primary patency (P = .53), partial (P = .08), or complete wound healing (P = .79) between groups. Reintervention was performed in 8 hospital (20.5%) and 14 OBL (45.2%) patients.

CONCLUSIONS

pDVA is a feasible and safe procedure for no-option critical limb ischemia in the hospital and OBL setting without significant differences in outcomes at ≤2 years.

Effects of L-Ornithine-L-Aspartate on Angiogenesis and Perfusion in Subacute Hind Limb Ischemia: Preliminary Study

The current treatment options for peripheral arterial disease (PAD) are limited due to a lack of significant high-level evidence to inform clinical decisions and unfavorable outcomes in terms of cost-effectiveness and amputation rates. In order to suggest the use of the commercially available L-Ornithine-L-Aspartate (LOLA) for treating PAD, we induced hind limb ischemia (HLI) by unilaterally ligating the femoral artery in a rat model. The rats were randomly divided into three groups, with seven rats assigned to each group: group 1 (control), group 2 (sorbitol), and group 3 (LOLA). Intraperitoneal injections were administered five times on post-operative days (PODs) 3, 5, 7, 10, and 12. Perfusion imaging was conducted on PODs 7 and 14 and compared to pre-operative perfusion imaging. Immunohistochemistry staining and Western blotting were performed after the final perfusion imaging. Group 3 showed a significant increase in perfusion, high CD31-positive capillary lumen density, and substantial overexpression of VEGF in the ischemic limb during the subacute phase of HLI. In conclusion, this study provides the first documented evidence of angiogenesis and perfusion recovery in the subacute phase of the HLI model following the administration of LOLA. With LOLA readily available on the commercial market, the implementation of LOLA treatment for PAD in humans can be expedited compared to other therapies still in the developmental stage.

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

BACKGROUND

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

DATA SOURCES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Development of a Fuzzy Diagnostic Model of Ischemic Disease of the Lower Limbs for Different Stages of Patient Management

Ischemic disease has severe impact on patients which makes accurate diagnosis vital for health protection. Improving the quality of prediction of patients with ischemic extremity disease by using hybrid fuzzy model allows for early and accurate prognosis of the development of the disease at various stages. The prediction of critical ischemia of lower extremity (CLI) at various disease stages is complex problem due to inter-related factors. We developed hybrid fuzzy decision rules to classify ischemic severity using clinical thinking (natural intelligence) with artificial intelligence, which allows achieving a new quality in solving complex systemic problems and is innovative. In this study mathematical model was developed to classify the risk level of CLI into: subcritical ischemia, favorable outcome, questionable outcome, and unfavorable outcome. The prognosis is made using such complex indicators as confidence that the patient will develop gangrene of the lower extremity (unfavorable outcome), complex coefficient of variability, and reversibility of the ischemic process. Model accuracy was calculated using representative control samples that showed high diagnostic accuracy and specificity characterizing the quality of prediction are 0.9 and higher, which makes it possible to recommend their use in medical practice.

Adherence to General Diabetes and Foot Care Processes, with Prompt Referral, Are Associated with Amputation-Free Survival in People with Type 2 Diabetes and Foot Ulcers: A Scottish National Registry Analysis

Aims

To compare different packages of care across care providers in Scotland on foot-related outcomes.

Methods

A retrospective cohort study with primary and secondary care electronic health records from the Scottish Diabetes Registry, including 6,845 people with type 2 diabetes and a first foot ulcer occurring between 2013 and 2017. We assessed the association between exposure to care processes and major lower extremity amputation and death. Proportional hazards were used for time-to-event univariate and multivariate analyses, adjusting for case-mix characteristics and care processes. Results were expressed in terms of hazard ratios with 95% confidence intervals.

Results

2,243 (32.7%) subjects had a major amputation or death. Exposure to all nine care processes at all ages (HR = 0.63; 95% CI: 0.58-0.69; p < .001) and higher foot care attendance in people aged >70 years (HR = 0.88; 0.78-0.99; p = .03) were associated with longer major amputation-free survival. Waiting time ≥ 12 weeks between ulceration and clinic attendance was associated with worse outcomes (HR = 1.59; 1.37-1.84; p < .001). In people > 70 years, minor amputations were associated with improved major amputation-free survival (HR = 0.69; 0.52-0.92; p = .01).

Conclusions

Strict adherence to a standardised package of general diabetes care before foot ulceration, timely foot care after ulceration, and specific treatment pathways were associated with longer major amputation-free survival among a large cohort of people with type 2 diabetes in Scotland, with a larger impact on older age groups.

Age-dependent outcome of first-line endovascular and surgical revascularization strategies in chronic limb-threatening ischemia

OBJECTIVE

Chronic limb-threatening ischemia (CLTI) has a high mortality and amputation risk even after revascularization. Due to an ageing population the incidence of peripheral arterial disease is rising. However, the current age distribution in patients with CLTI and the impact of age on outcome remains unclear. For this reason we performed an age-dependent analysis of mortality, morbidity, and amputation-free survival after open surgical revascularization (OSR) and endovascular revascularization therapy (ERT) with identification of risk factors for mortality. Standardized mortality ratios (SMR) were calculated, comparing observed deaths in the study population to expected deaths based on age and gender specific mortality rates of the overall Dutch population.

METHODS

Patients revascularized for a first episode of CLTI between 2013 and 2018 were included in this multicenter retrospective cohort study. The cohort was divided in two treatment groups (OSR and ERT) who were each stratified in three age groups: early age group <65 years (G1), middle age group 65-74 years (G2) and elderly age group ≥75 years (G3).

RESULTS

During the study period 274 limbs (43.9%) were treated with OSR and 350 limbs (56.1%) with ERT. The young population (G1) is only a small part of the whole CLTI population, namely for OSR 22% and ERT 18%. The risk profile of the early age group was characterized by male sex and smoking, while the elderly age group was characterized by poor arterial runoff, tissue loss, hypertension, hypercholesterolemia, chronic kidney disease, history of heart disease, COPD and cerebrovascular disease. One year amputation rates were similar between the age groups. However, significantly higher one year mortality rates were observed in patients ≥75 years in comparison to the low mortality rates in patients <75 years. (OSR: G3 19.8% vs G2 7.1% and G1 6.7%, P = .006; ERT: G3 30.7 vs G2 12.7% and G1 7.8%, P = .001). The SMR in this elderly group equaled 3.72 after OSR and 4.04 after ERT. Independent risk factors for mortality after OSR were age, hazard ratio (HR) 1.03 (95% confidence interval (CI) 1.01-1.06; P = .006), preoperative hemoglobin level, HR 0.79 (95% CI 0.67-0.92; P = .003), tissue loss, HR 1.85; 95% CI 1.22-2.79; P = .004), cardiac history, HR 1.56 (95% CI 1.06-2.30; P = .024) and development of postoperative delirium, HR 2.75 (95% CI 1.61-4.71; P < .001) . After ERT we identified age, HR 1.06 (95% CI 1.04-1.08; P < .001), preoperative hemoglobin level, HR 0.75 (95% CI 0.65-0.87; P < .001), tissue loss, HR 1.71 (95% CI 1.15-2.53; P = .008), history of chronic obstructive pulmonary disease (COPD), HR 1.99 (95% CI 1.43-1.79; P < .001), history of cerebrovascular accident (CVA), HR 1.55 (95% CI 1.09-2.21; P = .015), the development of postoperative pneumonia, HR 2.27 (95% CI 1.24-4.16; P = .008), postoperative acute kidney injury (AKI), HR 2.42 (95% CI 1.29-4.54; P = .006) and postoperative CVA, HR 8.17 (95% CI 1.96-34.15; P = .004) as risk factors.

CONCLUSIONS

The current CLTI population consists mostly of elderly patients and only a small part is younger than 65 years. This shift in the population is important because increasing age is associated with considerable higher one year mortality rates regardless of the method of revascularization in patients with CLTI. The mortality rates in the elderly group are three to four times larger than expected in the general population. In relation to the high mortality of the elderly patient, we assume that interventions to prevent postoperative delirium and correct preoperative anemia may be warranted as they appear to be independent risk factors for mortality.

Paclitaxel in real-life data is not associated with reduced survival but has limited benefit in preventing amputation

BACKGROUND

Recent meta-analysis of randomized-controlled trials reported an increased risk of long-term mortality in patients treated with paclitaxel-coated devices (PCD) for femoropopliteal arteries (FP) lesions. However, real-life data on the subject is contradictory and data from CLTI patients is missing. The authors aim to evaluate the impact of PCD for the treatment of FP lesions on long-term mortality and amputation on a real-life cohort up to 5 years.

METHODS

All patients treated for FP lesions with endovascular devices from January 2013 to December 2016 were included, irrespective of clinical presentation. Primary endpoint is overall survival. Secondary endpoints are freedom-from major amputation and amputation-free survival. Survival estimates were obtained using Kaplan-Meier plots and a multivariable model was constructed to correct for relevant baseline differences.

RESULTS

From 2013 to 2016, 351 patients with FP lesions were treated, 250 with uncoated devices (nPCD) and 101 with PCD. Patients treated with nPCD were significantly older, more often female and with more severe degrees of ischemia. Median follow-up was 55(20-71) months. Overall survival and amputation-free survival were significantly higher in patients treated with PCD. Survival at one-year was 79% vs. 92%, at two-years 69% vs. 79% and at five-years 50% vs. 65% (P=.02). AFS was 43% vs. 57% at 5-years(P=.016). Freedom-from major amputation was similar between groups. After correction for relevant baseline differences on multivariable analysis, the survival advantage for patients treated with PCD was lost at 2 and 5 years.

CONCLUSIONS

Our results do not confirm the findings of increased mortality associated with PCD. However, no improvement in amputation rate was found. For the time, our institutional data does not support withholding PCD to reduce mortality but suggests that the benefit in preventing amputation is not significant.

Deep Venous Arterialization for Chronic Limb Threatening Ischemia in Atherosclerosis Patients - A meta-analysis

BACKGROUND

Venous arterialization is an upcoming and novel alternative in chronic limb threatening ischemia (CLTI) patients in the absence of standard revascularization options. The aim of this study is to systematically review and analyze outcomes of venous arterialization.

STUDY DESIGN

A systematic literature search was performed in 5 databases using the PRISMA methodology. Inclusion criteria were English language original research papers on CLTI patients treated with venous arterialization.

EXCLUSION CRITERIA

absence of CLTI due to atherosclerosis, duplicate study or reporting of patients, meeting abstract only. Quality and risk of bias were evaluated. Meta-analysis was performed using random effects model on articles that have a sample size of equal or greater than 10.

RESULTS

Twelve studies included 442 patients that underwent treatment for 445 limbs (374 patients and 377 limbs underwent venous arterialization while remainder underwent traditional bypass and served as control subjects). Average age was 66 [18 studies, range 37-91 years], 68% were male [271/366, 15 studies] and 67% diabetic [271/406, 16 studies]). Most limbs (88%, 352/398, 16 studies) had tissue loss. Pooled 30-day mortality was 3.7% (95%-confidence interval [CI] 0.8-6.6%), 30-day morbidity was 15.5% (95%-CI 3.2-27.8%), 30-day major adverse cardiovascular event was 5.2% (95%-CI 1.7-8.6%) and 30-day major adverse limb event was 16.7% (95%-CI 1.5-31.9%). Pooled 1-year limb-salvage rate was 79.0% (95%-CI 68.7-90.7) and 1-year survival rate was 85.7% (95%-CI 76.2-96.4). Studies quality varied significantly across studies.

CONCLUSION

Venous arterialization has an acceptable a 1-year limb salvage rate of 79%, however, this is based on low levels of evidence. More randomized controlled trials or high-quality cohort studies are needed to further define the effectiveness of this procedure for CLTI.

Propensity-matched analysis does not support angiosome-guided revascularization of multilevel peripheral artery disease (PAD)

BACKGROUND

This retrospective comparative cohort study evaluated the clinical outcome of angiosome-guided endovascular arterial reconstructions in chronic limb-threatening ischemia (CLTI) due to multilevel peripheral artery disease (PAD).

METHODS

Patients treated in an endovascular fashion for CLTI with tissue loss due to multilevel PAD were analyzed. Limbs were classified as having undergone either angiosome-guided (direct) revascularization (DR) or nonangiosomic (indirect) revascularization (IR). DR was defined as uninterrupted in-line flow to the affected angiosome, revascularization through the pedal arch was also considered direct. Groups were adjusted with propensity score (PS) matching and compared for amputation-free survival (AFS), freedom from major adverse limb events (MALE), and healing rate at 12 months.

RESULTS

A total of 174 patients (81 men, mean age 70.0 ± 10.4 y) were included. PS matching produced two groups of 55 patients each: DR (24 men, mean age 71.7 ± 10.7 y) and IR (26 men, mean age 72.0 ± 9.4 y). The matched groups had no significant differences in baseline variables. At 12 months there were no significant differences in AFS (73.2% vs 71.6%; p = 0.841), freedom from MALE (71.7% vs 66.1%; p = 0.617), and healing rate (72.7% vs 72.0%; p = 1.000) between DR and IR, respectively.

CONCLUSION

This study failed to support the use of angiosome concept in CLTI due to multilevel disease.

The Society for Vascular Surgery Objective Performance Goals for Critical Limb Ischemia are attainable in select patients with ischemic wounds managed with wound care alone

BACKGROUND

To set therapeutic benchmarks, in 2009 the Society for Vascular Surgery defined objective performance goals (OPG) for treatment of patients with chronic limb threatening ischemia (CLTI) with either open surgical bypass or endovascular intervention. The goal of these OPGs are to set standards of care from a revascularization standpoint and to provide performance benchmarks for 1 year patency rates for new endovascular therapies. While OPGs are useful in this regard, a critical decision point in the treatment of patients with CLTI is determining when revascularization is necessary. There is little guidance in the comprehensive treatment of this patient population, especially in the nonoperative cohort. Guidelines are needed for the CLTI patient population as a whole and not just those revascularized, and our aim was to assess whether CLTI OPGs could be attained with nonoperative management alone.

METHODS

Our cohort included patients with an incident diagnosis of CLTI (by hemodynamic and symptomatic criteria) at our institution from 2013-2017. The primary outcome measured was mortality. Secondary outcomes were limb loss and failure of amputation-free survival. Descriptive statistics were used to define the 2 groups - patients undergoing primary revascularization and patients undergoing primary wound management. The risk difference in outcomes between the 2 groups was estimated using collaborative-targeted maximum likelihood estimation.

RESULTS

Our cohort included 349 incident CLTI patients; 60% male, 51% white, mean age 63 +/- 13 years, 20% Rutherford 4, and 80% Rutherford 5. Most patients (277, 79%) underwent primary revascularization, and 72 (21%) were treated with wound care alone. Demographics and presenting characteristics were similar between groups. Although the revascularized patients were more likely to have femoropopliteal disease (72% vs. 36%), both groups had a high rate of infrapopliteal disease (62% vs. 57%). Not surprisingly, the patients in the revascularization group were less likely to have congestive heart failure (34% vs. 42%), complicated diabetes (52% vs. 79%), obesity (19% vs. 33%), and end stage renal disease (14% vs. 28%). In the wound care group, 2-year outcomes were 65% survival, 51% amputation free survival, 19% major limb amputation, and 17% major adverse cardiac event. The wound care cohort had a 13% greater risk of death at 2 years; however, the risk of limb loss at 2 years was 12% less in the wound care cohort.

CONCLUSIONS

A comprehensive set treatment goals and expected amputation free survival outcomes can guide revascularization, but also assure that appropriate outcomes are achieved for patients treated without revascularization. The 2-year outcomes achieved in this cohort provide an estimate of outcomes for nonrevascularized CLTI patients. Although multi-center or prospective studies are needed, we demonstrate that equal, even improved, limb salvage rates are possible.

Medical Therapy for Secondary Prevention of Atherothrombotic Events in Peripheral Artery Disease

Patients with peripheral artery disease (PAD) are at risk for severe morbidity and mortality, including ischaemic-related events. Furthermore, there is heterogeneity within the PAD population, where the drivers of risk for cardiovascular and limb-specific ischaemic events differ. Patients with PAD with concomitant coronary artery disease are at increased risk for cardiovascular ischaemic events, whereas patients with PAD with a prior history of lower-extremity revascularization are at increased risk for limb-specific ischaemic events. The current therapeutic challenge is identifying these risk factors to tailor therapy optimally for each patient. Additionally, the majority of our current medical therapeutics in patients with PAD have been shown to reduce atherothrombotic events, such as myocardial infarction, stroke and cardiovascular death, with a paucity of medical therapeutics specifically targeting a reduction in limb-specific ischaemic events. Over the past several years, there have been several contemporary clinical trials evaluating antithrombotic agents and their efficacy in reducing limb-specific ischaemic events. Specifically, rivaroxaban, with the addition of aspirin, has emerged as an efficacious therapeutic. In this article, we provide a review of the current clinical burden of PAD, the rationale behind current PAD medical therapeutics and the contemporary trials that have described the benefit of a novel therapeutic in PAD, rivaroxaban.

Prognostic value of C-reactive protein to albumin ratio for long-term outcomes of patients with peripheral arterial disease underwent endovascular treatment

BACKGROUND

Peripheral artery disease (PAD) is part of the systemic atherosclerotic process that is highly associated with cardiovascular diseases. Despite successful endovascular treatment (EVT) strategies, mortality and morbidity rates still remain higher in PAD patients. C-reactive protein (CRP) and albumin are biomarkers of inflammation and malnutrition that play key roles in the progression of peripheral arterial disease. In this study, we aimed to investigate the relationship between CRP-to-albumin ratio (CAR) and mortality and amputation-free survival in patients with PAD after successful EVT.

METHOD

Our study enrolled 149 consecutive patients who underwent EVT on atherosclerotic obstruction of iliac, femoral, popliteal and/or below-knee arteries with the clinical features of PAD and/or chronic limb-threatening ischaemia between January 2015 and January 2020. Clinical and prognostic follow-up of patients had been done at the outpatient clinic and were collected from institution's medical records.

RESULTS

The mean follow-up period was 22 months (14-40). All-cause mortality and amputation rates of patients in the high CAR group were significantly higher than those in the low CAR group (21.3% vs. 6.8% and 18.7% vs. 5.4%, respectively). Kaplan-Meier survival analysis showed significantly better survival for patients in the low CAR group (log-rank p = 0.0058). In multivariate logistic regression analysis, CAR was found to be an independent predictor of amputation and all-cause mortality even after adjusting for other confounding risk factors. ROC curve analysis revealed the optimal cut-off value of CAR for predicting all-cause mortality and amputation to be >1.476 with a sensitivity of 48.5% and specificity of 94.0%.

CONCLUSION

The inflammatory state reflected by CAR levels was strongly associated with all-cause mortality and amputation after EVT in patients with PAD. Furthermore, CAR was found to be an independent predictor of these clinical outcomes after adjusting for other clinically associated parameters.

Long Term Survival and Limb Salvage in Patients With Non-Revascularisable Chronic Limb Threatening Ischaemia

OBJECTIVE

The aim of this study was to provide long term survival and limb salvage rates for patients with non-revascularisable (NR) chronic limb threatening ischaemia (CLTI).

METHODS

This was a retrospective review of prospectively collected data, derived from a randomised controlled trial (JUVENTAS) investigating the use of a regenerative cell therapy. Survival and limb salvage of the index limb in CLTI patients without viable options for revascularisation at inclusion were analysed retrospectively. The primary outcome was amputation free survival, a composite of survival and limb salvage, at five years after inclusion in the original trial.

RESULTS

In 150 patients with NR-CLTI, amputation free survival was 43% five years after inclusion. This outcome was driven by an equal rate of all cause mortality (35%) and amputation (33%). Amputation occurred predominantly in the first year. Furthermore, 33% of those with amputation subsequently died within the investigated period, with a median interval of 291 days.

CONCLUSION

Five years after the initial need for revascularisation, about half of the CLTI patients who were deemed non-revascularisable survived with salvage of the index limb. Although the prospects for these high risk patients are still poor, under optimal medical care, amputation free survival seems comparable with that of revascularisable CLTI patients, while the major amputation rate within one year, especially among NR-CLTI patients with ischaemic tissue loss, is very high.

Clinical practice patterns and ascertainment bias for cardiovascular events in a randomized trial: A survey of investigators in the BEST-CLI trial

Ascertainment bias is a well-recognized source of bias in research, but few studies have systematically analyzed sources of ascertainment bias in randomized trials in which blinding is not possible and endpoint assessment is not protocolized. In the current study, we sought to evaluate differences in the clinical practice patterns of trial investigators with respect to bias in the ascertainment of pre-revascularization patient risk and the incidence of secondary endpoints post-revascularization. We conducted a cross-sectional survey of active investigators (n = 936) from the Best Endovascular Versus Best Surgical Therapy for Patients with Critical Limb Ischemia (BEST-CLI) trial. The total survey response rate was 19.6% (183/936). Vascular surgeons were more likely than nonsurgical interventionalists to order tests for cardiac complications after both surgical bypass (p < 0.001) and endovascular revascularization (p = 0.038). Post-procedure, investigators were more likely to order additional testing for cardiac complications in open surgery versus endovascular cases (7% vs 16% never, 41% vs 65% rarely, 43% vs 17% sometimes, 9% vs 2% always, respectively; p < 0.0001). Significant variation in practice patterns exist in the pre- and post-procedure assessment of cardiac risk and events for patients with CLI undergoing revascularization. Variation in the ascertainment of risk and outcomes according to the type of revascularization procedure and physician specialty should be considered when interpreting the results of clinical studies, such as the BEST-CLI trial. ClinicalTrials.gov Identifier: NCT02060630.

Temporal trends and outcomes of critical limb ischemia among patients with chronic kidney disease

There is a paucity of data on the outcomes and revascularization strategies for critical limb ischemia (CLI) among patients with chronic kidney disease (CKD). Hence, we conducted a nationwide analysis to evaluate the trends and outcomes of hospitalizations for CLI with CKD. The National Inpatient Sample database (2002-2015) was queried for hospitalizations for CLI. The trends of hospitalizations for CLI with CKD were reported, and endovascular versus surgical revascularization strategies for CLI with CKD were compared. The main study outcome was in-hospital mortality. The analysis included 2,139,640 hospitalizations for CLI, of which 484,224 (22.6%) had CKD. There was an increase in hospitalizations for CLI with CKD (Ptrend = 0.01), but a reduction in hospitalizations for CLI without CKD (Ptrend = 0.01). Patients with CLI and CKD were less likely to undergo revascularization compared with patients without CKD. CLI with CKD had higher rates of in-hospital mortality (4.8% vs 2.5%, adjusted odds ratio (OR) 2.01; 95% CI 1.93-2.11) and major amputation compared with no CKD. Revascularization for CLI with CKD was associated with lower rates of mortality (3.7% vs 5.3%, adjusted-OR 0.78; 95% CI 0.72-0.84) and major amputation compared with no revascularization. Compared with endovascular revascularization, surgical revascularization for CLI with CKD was associated with higher rates of in-hospital mortality (4.7% vs 2.7%, adjusted-OR 1.67; 95% CI 1.43-1.94). In conclusion, this contemporary observational analysis showed an increase in hospitalizations for CLI among patients with CKD. CLI with CKD was associated with higher in-hospital mortality compared with no CKD. Compared with endovascular therapy, surgical revascularization for CLI with CKD was associated with higher in-hospital mortality.

Contemporary Revascularization Strategies and Outcomes Among Patients With Diabetes With Critical Limb Ischemia: Insights From the National Inpatient Sample

OBJECTIVES

The purpose of this study was to evaluate temporal trends in the frequency of revascularization and associated outcomes in patients with diabetes mellitus and critical limb ischemia (CLI).

BACKGROUND

Little is known about outcomes following revascularization for CLI in patients with diabetes mellitus.

METHODS

Temporal trends in hospitalization for CLI among patients with diabetes were determined using the 2002-2015 National Inpatient Sample database. Propensity score matching was used to compare patients who underwent revascularization with those who did not and, separately, to compare those who underwent endovascular versus surgical revascularization. The main study outcome was in-hospital mortality.

RESULTS

The analysis included 1,222,324 hospitalizations. The number of hospitalizations for CLI among patients with diabetes increased over time (ptrend < 0.001). There was an increase in the use of lower extremity revascularization, paralleled by a decline in in-hospital mortality during the study period. In the matched cohort, patients who were revascularized had lower in-hospital mortality (odds ratio [OR]: 0.68; 95% confidence interval [CI]: 0.63 to 0.72) and major amputation (OR: 0.25; 95% CI: 0.24 to 0.27) compared with those who were treated medically. Compared with endovascular revascularization, those who underwent surgical revascularization had higher rates of in-hospital mortality (OR: 1.18; 95% CI: 1.04 to 1.35) but lower rates of major amputation (OR: 0.75; 95% CI: 0.70 to 0.81). Major bleeding, blood transfusion, post-operative infection, respiratory complications, discharges to nursing facility, and longer length of hospital stay were also more common among those who underwent surgery.

CONCLUSIONS

In this national analysis of patients with DM and CLI, we demonstrated an increase in hospitalization for CLI among patients with diabetes in the United States. Although in-hospital mortality decreased over time regardless of the treatment strategy used, this outcome occurred less frequently among those who underwent revascularization than not. Compared with surgical revascularization, endovascular revascularization was associated with lower in-hospital mortality but higher rates of major amputation.

A Review and Proposed Classification System for the No-Option Patient With Chronic Limb-Threatening Ischemia

A growing, but poorly defined subset of patients with chronic limb-threatening ischemia (CLTI) have "no option" for revascularization. One notable subgroup includes patients with severe ischemia and advanced pedal artery occlusive disease, termed "desert foot," who are at high risk for major amputation due to a lack of conventional revascularization options. Although new therapies are being developed for no-option patients with desert foot anatomy, this subgroup and the broader group of no-option patients are not well defined, limiting the ability to evaluate outcomes. Based on a systematic review, a classification of the no-option CLTI patient was constructed for use in clinical practice and studies. Several no-option conditions were identified, including type I-severe and pedal occlusive disease (desert foot anatomy) for which there is no accepted method of repair; type II-lack of suitable venous conduit for bypass in the setting of an acceptable target for bypass; type III-extensive tissue loss with exposure of vital structures that renders salvage impossible; type IV-advanced medical comorbidities for which available revascularization options would pose a prohibitive risk; and type V-presence of a nonfunctional limb. While type I and type II patients may have no option for revascularization, type III and type V patients have wounds, infection, comorbidities, or functional status that may leave them with few options for revascularization. As treatment strategies continue to evolve and novel methods of revascularization are developed, the ability to identify no-option patients in a standardized fashion will aid in treatment selection and assessment of outcomes.

Extent of heel ulceration influences the outcomes in patients with isolated infrapopliteal limb threatening critical ischemia

BACKGROUND

The aim of the present study was to assess the effects of the extent of heel ulceration on the outcomes of limb threatening critical ischemia due to isolated infrapopliteal disease.

METHODS

A retrospective review identified 989 patients with isolated infrapopliteal disease and heel ulceration treated from 2001 to 2018. The heel was defined as the back of the foot, extending from the Achilles tendon to around the plantar surface and covering the apex of the calcaneum bone. Heel ulceration was categorized into three groups by area: <5 cm², 5 to 10 cm², and >10 cm². The interventions were endovascular, open bypass, major amputation, and wound care. An intention-to-treat analysis by patient group was performed. The 30-day outcomes and amputation-free survival (AFS; survival without a major amputation) were evaluated.

RESULTS

Of the 989 patients, 384 (58% male; average age, 65 years; n = 768 vessels) had undergone isolated endovascular tibial intervention, 124 (45% male; average age, 59 years) had undergone popliteal tibial vein bypass for limb threatening critical ischemia, 219 (52% male; average age, 67 years) had undergone major amputation, and 242 (49% male; average age, 66 years) had received wound care. No difference was found in the 30-day major adverse cardiac events in the endovascular and open bypass groups, with significantly more events in the major amputation group (P = .03). The 30-day major adverse limb events and 30-day amputation rates were equivalent between the open bypass and endovascular groups. The 5-year AFS rate was superior in the open bypass group (37% ± 8%; mean ± standard error of the mean) compared with the endovascular group (27% ± 9%; P = .04). The wound care group had a 5-year AFS rate of 20% ± 9%, which was not significantly different from that of the endovascular group. Patients with heel ulcers of <5 cm² had better AFS (47% ± 8%) than those with 5- to 10- cm² heel ulceration (24% ± 9%). Heel ulcers >10 cm² were associated with markedly worse 5-year AFS outcomes (0% ± 0%). The presence of end-stage renal disease, osteomyelitis, uncontrolled diabetes (hemoglobin A_1c >10%), and/or frailty combined with a heel ulcer >10 cm² were predictive of poor AFS.

CONCLUSIONS

An increasing heel ulcer area combined with osteomyelitis and systemic comorbidities was associated with worsening 30-day outcomes and 5-year AFS, irrespective of the therapy chosen.

The Role of Lower Extremity Amputation in Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia (CLTI) is a severe form of peripheral artery disease associated with high rates of limb loss. The primary goal of treatment in CLTI is limb salvage via revascularization. Multidisciplinary teams provide improved care for those with CLTI and lead to improved limb salvage rates. Not all patients are candidates for revascularization, and a subset will require major amputation. This article highlights the role of amputations in the management of CLTI, and describes the patients who should be offered primary amputation.

Midterm Outcomes of Percutaneous Deep Venous Arterialization With a Dedicated System for Patients With No-Option Chronic Limb-Threatening Ischemia: The ALPS Multicenter Study

Purpose: To evaluate the midterm results of patients suffering from no-option chronic limb-threatening ischemia (CLTI) treated with a dedicated system for percutaneous deep venous arterialization (pDVA). Materials and Methods: Thirty-two consecutive CLTI patients (mean age 67±14 years; 20 men) treated with pDVA using the Limflow device at 4 centers between 11 July 2014 and 11 June 2018 were retrospectively analyzed. Of all patients, 21 (66%) had diabetes, 8 (25%) were on immunosuppression, 4 (16%) had dialysis-dependent renal failure, 9 (28%) had Rutherford category 6 ischemia, and 25 (78%) were deemed at high risk of amputation. The primary outcome was amputation-free survival (AFS) at 6 months. Secondary outcomes were wound healing, limb salvage, and survival at 6, 12, and 24 months. Results: Technical success was achieved in 31 patients (96.9%). The median follow-up was 34 months (range 16-63). At 6, 12, and 24 months, estimates were 83.9%, 71.0%, and 67.2% for AFS, 86.8%, 79.8% and 79.8% for limb salvage, and 36.6%, 68.2%, and 72.7% for complete wound healing, respectively. Median time to complete wound healing was 4.9 months (range 0.5-15). The DVA circuit occluded during follow-up in 21 patients; the median time to occlusion was 2.6 months. Reintervention for occlusion was performed in 17 patients: 16 because of unhealed wounds and 1 for a newly developed ulcer. Conclusion: This study represents the largest population of patients with no-option CLTI treated with pDVA using the LimFlow device with midterm results. In this complex group of patients, pDVA using the LimFlow device has been shown to be feasible, with a high technical success rate and AFS at 6 up to 24 months coupled with wound healing. In selected patients with no-option CLTI, pDVA could be a recommended treatment to prevent amputation and heal wounds.

Impact of Therapeutic Angiogenesis Using Autologous Bone Marrow-derived Mononuclear Cell Implantation in Patients with No-option Critical Limb Ischemia

Recently, the limb salvage rate of patients with critical limb ischemia (CLI) has been improved due to the development of revascularization and wound care treatment. However, many patients with CLI are refractory to standard treatments, including revascularization such as endovascular treatment or surgical bypass. Establishment of a new cell therapy is required to improve the limb salvage rate and prognosis in patients with CLI. In 1997, endothelial progenitor cells were found to be derived from the bone marrow to circulate as CD34 surface antigen positive cells in peripheral blood and to affect therapeutic angiogenesis in ischemic tissues. Later, therapeutic angiogenesis using autologous bone marrow-derived mononuclear cell (BM-MNC) implantation was performed for patients with no-option CLI in clinical practice. Several reports showed the safety and efficacy of the BM-MNC implantation in patients with CLI caused by arteriosclerosis obliterans, thromboangiitis obliterans (TAO), and collagen diseases. In particular, in patients with CLI caused by TAO, limb salvage rate was significantly improved compared with standard treatments. The BM-MNC implantation may be feasible and safe in patients with no-option CLI. Here, we review the efficacy of BM-MNC implantation in no-option CLI, with a focus on therapeutic angiogenesis.

A conservative approach to select patients with ischemic wounds is safe and effective in the setting of deferred revascularization

OBJECTIVE

The Wound, Ischemia, and foot Infection classification system has been validated to predict benefit from inmediate revascularization and major amputation risk among patients with peripheral arterial disease. Our primary goal was to evaluate wound healing, limb salvage, and survival among patients with ischemic wounds undergoing revascularization when intervention was deferred by a trial of conservative wound therapy.

METHODS

All patients with peripheral arterial disease and tissue loss are prospectively enrolled into our Prevention of Amputation in Veterans Everywhere limb preservation program. Limbs are stratified into a validated pathway of care based on predetermined criteria (immediate revascularization, conservative treatment, primary amputation, and palliative care). Limbs allocated to the conservative strategy that failed to demonstrate adequate wound healing and were candidates, underwent deferred revascularization. Rates of wound healing, freedom from major amputation, and survival were compared between patients who underwent deferred revascularization with those who received immediate revascularization by univariate and multivariate analysis.

RESULTS

Between January 2008 and December 2017, 855 limbs were prospectively enrolled into the Prevention of Amputation in Veterans Everywhere program. A total of 203 limbs underwent immediate revascularization. Of 236 limbs stratified to a conservative approach, 185 (78.4%) healed and 33 (14.0%) underwent deferred revascularization (mean, 2.7 ± 2.6 months). The mean long-term follow-up was 51.7 ± 37.0 months. Deferred compared with immediate revascularization demonstrated similar rates of wound healing (66.7% vs 57.6%; P = .33), freedom from major amputation (81.8% vs 74.9%; P = .39), and survival (54.5% vs 50.7%; P = .69). After adjustment for overall Wound, Ischemia, and foot Infection stratification stages, deferred revascularization remained similar to immediate revascularization for wound healing (hazard ratio [HR], 1.5; 95% confidence interval [CI], 0.7-3.2), freedom from major amputation (HR, 0.7; 95% CI, 0.3-1.7) and survival (HR, 1.2; 95% CI, 0.6-2.4).

CONCLUSIONS

Limbs with mild to moderate ischemia that fail a trial of conservative wound therapy and undergo deferred revascularization achieve similar rates of wound healing, limb salvage, and survival compared with limbs undergoing immediate revascularization. A stratified approach to critical limb ischemia is safe and can avoid unnecessary procedures in selected patients.

Limb salvage in diabetic patients with no-option critical limb ischemia: outcomes of a specialized center experience

Objective: To describe the characteristics, the management and the outcome of a consecutive series of patients with diabetic foot lesions (DF) and no-option critical limb ischemia (CLI) treated with a multidimensional, interdisciplinary approach in a dedicated center. Research Design and Methods: The prospective database of the Diabetic Foot Unit of the Maria Cecilia Hospital (Cotignola, Italy) collects medical history, risk factors, chemistry values, angiographic data, characteristic of foot lesions, medical and surgical therapies of all patients admitted with a diagnosis of DF and CLI. All patients were followed-up for at least 1 year and/or total recovery. The primary endpoint was 1-year amputation-free survival (AFS), secondary endpoints were limb salvage and survival. Results: Between October 2014 and October 2017, 1024 patients with DF and CLI were admitted to the center. Eighty-four of them (8.2%) fulfilled the criteria for no-option CLI. At 1 year, AFS, limb salvage, and survival rates were 34%, 34%, and 83%, respectively. Lesions located proximal to the Lisfranc joint were associated with major amputation (HR 2.1 [1.2-3.6]). One-year survival of patients treated with minor procedures was significantly higher compared to patients treated with major amputation (96% vs 76%, log-rank p = 0.019). Major amputation was independently associated with mortality (HR 7.83 [1.02-59.89]). Conclusions: The application of dedicated and standardized strategies permitted limb salvage in one-third of patients with no-option CLI. Patients with stable lesions limited to the forefoot and without ischaemic pain had a greater probability to successfully receive conservative treatments. Limb salvage was associated with subsequent higher one-year survival.

Endovascular Extra-Anatomic Femoro-Popliteal Bypass for Limb Salvage in Chronic Critical Limb Ischemia

PURPOSE

To report the initial clinical experience with fully endovascular extra-anatomic femoro-popliteal bypass (FPB) for limb salvage in patients with critical limb ischemia (CLI) and no traditional endovascular or surgical revascularization options.

METHODS

Between June 2013 and May 2018, endovascular procedure was proposed for limb salvage during multidisciplinary team meeting in fifteen hospitalized patients (median age 67 years; 73% men) with CLI and a high risk of major amputation. Primary outcome was amputation-free survival at 1 year. Secondary outcomes included mortality, cardiovascular (CV) events and major limb amputation at 1 year, primary/secondary bypass patency and wound healing at the last follow-up visit. Procedure-related complications (deaths, CV events, hemorrhages) were recorded through 30 days.

RESULTS

Technical procedure success rate was 100%. Major peri-procedural outcomes occurred in two patients (13%): One patient died secondary to cardiogenic shock; one patient suffered acute coronary syndrome associated with iliopsoas bleeding. No major amputation occurred through 30 days. Median follow-up period was 21.5 (18.25-45.5) months (last follow-up visits on April 2019). Amputation-free survival at 1-year and at the last follow-up visit was 80% and 53%, respectively. Cumulative mortality at 1-year and at the last follow-up visit was 13% and 33%, respectively. Primary and secondary bypass patency was 27% and 60%, respectively. Complete wound healing was achieved in 11 patients (73%).

CONCLUSION

Endovascular extra-anatomic FPB represents an innovative approach for limb salvage in CLI with no traditional endovascular or surgical revascularization options. Our clinical experience highlights that this technique remains challenging because of frequent comorbidities and fragility of this patient population.

LEVEL OF EVIDENCE

Level 4, Case series.

Hybrid Foot Vein Arterialization in No-Option Patients With Critical Limb Ischemia: A Preliminary Report

PURPOSE

To describe a preliminary experience in treating no-option critical limb ischemia (CLI) patients with a hybrid foot vein arterialization (HFVA) technique combining open plus endovascular approaches.

MATERIALS AND METHODS

Between May 2016 and January 2018, 35 consecutive patients (mean age 68±12 years; 28 men) with 36 no-option CLI limbs underwent HFVA in our center. All limbs had grade 3 WIfI (Wound, Ischemia, and foot Infection) ischemia, and the wound classification was grade 1 in 4 (11%) limbs, grade 2 in 4 (11%), and grade 3 in 28 (78%). Surgical bypass was done on the medial marginal vein or a posterior tibial vein, followed by endovascular removal of foot vein valves and embolization of foot vein collaterals. A "tension-free" surgical approach was used to treat foot lesions.

RESULTS

At a mean follow-up of 10.8±2 months, limb salvage was achieved in 25 (69%) limbs and wound healing in 16 (44%); 9 patients presented an unhealed wound. Eleven (31%) patients underwent a major amputation (2 below the knee and 9 thigh). One patient with an unhealed wound and open bypass died of myocardial infarction.

CONCLUSION

HFVA is a promising technique able to achieve acceptable rates of limb salvage and wound healing in no-option patients generally considered candidates for an impending major amputation. Further studies are needed to standardize the technique and better identify patients who can benefit from this approach.

Cell Therapy for Chronic Limb-Threatening Ischemia: Current Evidence and Future Directions

Cell‐based therapies have gained interest as a potential treatment method in cardiovascular disease in the past two decades, peripheral artery disease amongst others. Initial pre‐clinical and small pilot clinical studies showed promising effects of cell therapy in peripheral artery disease and chronic limb‐threatening ischemia in particular. However, these promising results were not corroborated in larger high quality blinded randomized trials. This has led to a shift of the field towards more sophisticated cell products, especially mesenchymal stromal cells. Mesenchymal stromal cells have some important benefits, making these cells ideal for regenerative medicine, e.g., potential for allogeneic application, loss of disease‐mediated cell dysfunction, reduced production costs, off‐the‐shelf availability. Future high quality and large clinical studies have to prove the efficacy of mesenchymal stromal cells in the treatment of peripheral artery disease. Stem Cells Translational Medicine2018;7:842–846

Outcomes of upper extremity interventions for chronic critical ischemia

BACKGROUND

Critical hand ischemia owing to below-the-elbow atherosclerotic occlusive disease is relatively uncommon. The aim of this study was to examine the outcomes in patients presenting with critical ischemia owing to below-the-elbow arterial atherosclerotic disease who underwent nonoperative and operative management.

METHODS

A database of patients undergoing operative and nonoperative management for symptomatic below-the-elbow atherosclerotic disease between 2006 and 2016 was retrospectively queried. Patients with critical ischemia (tissue loss and rest pain) were identified. Three management groups were identified: no revascularization (None), endovascular revascularization (Endo), and open revascularization by bypass (Bypass). Patients with acute embolism, active vasculitis, end-stage renal disease, ipsilateral dialysis access complications of steal, and ipsilateral trauma were excluded.

RESULTS

One hundred eight patients (56% male; average age, 59 years) presented with symptomatic below-the-elbow disease: 93% presented with digital ulceration and the remainder with rest pain. Eighty-one percent had diabetes and 41% had chronic renal insufficiency (not on dialysis). All underwent catheter-based angiography. Fifty-three patients (49%) had no intervention and subsequently were committed to wound care; 26 of these required no further intervention, 10 had an interval palmar sympathectomy, and 17 underwent either a phalanx or digital amputation. Thirty-four patients (31%) underwent an endovascular intervention with a median of 1.5 vessels (ulnar, radial, or interosseous arteries) intervened on. Technical success was achieved in 29 patients (85%). Of the five technical failures, two went on to bypass, one had a focal endarterectomy and patch angioplasty, and one was treated conservatively. Ten patients in the Endo group required either a phalanx or digital amputation. Twenty-one patients (19%) underwent a saphenous vein bypass (reversed or nonreserved) to the radial in 12 and the ulnar in 11 limbs. In follow-up, 11 patients underwent open or endovascular intervention to maintain patency of the bypass. There were nine phalanx or digital amputations in the Bypass group. No below-the-elbow or above-the-elbow amputations were performed within 30 days. The wound healing rate without amputation was 78% (85 of 108). The predictors of wound healing were technical success of the revascularization, intact palmar arch and presence of digital run-off. The presence of an incomplete arch and poor digital run-off were associated with a phalanx or digital amputation.

CONCLUSIONS

Upper extremity interventions for critical ischemia are associated with a high rate of success. Major amputations are rare and the many can be treated nonoperatively. In appropriately selected patients, both endovascular and open interventions have a high rate of success.

No Clinical Benefit of Intramuscular Delivery of Bone Marrow-derived Mononuclear Cells in Nonreconstructable Peripheral Arterial Disease: Results of a Phase-III Randomized-controlled Trial

BACKGROUND AND AIMS

Prospects for no-option, end-stage peripheral artery disease (PAD) patients remain poor. Although results from open and semiblinded studies fuel hope for cell-based strategies in no-option patients, so far conclusions from the available placebo-controlled studies are not supportive. With the intention to end the remaining controversy with regard to cell therapy for PAD we conducted a confirmatory, double-blinded randomized placebo-controlled phase 3 trial.

STUDY DESIGN

This randomized controlled trial was registered (NCT00539266). Inclusion criteria included stable or progressive disabling PAD, no imminent need for amputation, absent accepted options for revascularization. Diabetic disease was an exclusion criterion. Bone marrow (500-700 mL) was harvested and bone marrow-derived mononuclear cells were concentrated to 40 mL. Concentrated cells or placebo (diluted blood) were intramuscularly injected at 40 locations of the calf muscle.

RESULTS

Fifty-four patients (mean (sd) age 58.2 (14.2) yrs, 58% males) were randomized. Twenty-eight patients received BM-MNCs, 26 placebo. Baseline criteria were similar in the 2 groups. No significant differences were observed for the primary (number of amputations, (pain free) walking distance) and secondary outcome parameters (ankle brachial index, pain scores, quality of life (SF-36)).

DISCUSSION

This fully blinded replication trial of autologous BM-MNC fails to confirm a benefit for cell therapy in no-option PAD patients, consequently BM-MNC therapy should not be offered as a clinical treatment. Apparent contrasting conclusions from open and controlled studies underscore the importance of a controlled trial design in evaluating cell-based interventions in PAD.

One-Year Results of First-Line Treatment Strategies in Patients With Critical Limb Ischemia (CRITISCH Registry)

PURPOSE

To examine the outcomes of all first-line strategies for the treatment of critical limb ischemia (CLI), identify factors that influenced the treatment choice, and determine the risk of amputation or death after each treatment.

METHODS

CRITISCH ( ClinicalTrials.gov identifier NCT01877252) is a multicenter, national, prospective registry evaluating all available treatment strategies applied in 1200 consecutive CLI patients in 27 vascular centers in Germany. The recruitment started in January 2013 and was completed in September 2014. Treatment options were endovascular revascularization (642, 53.5%), bypass surgery (284, 23.7%), femoral artery patchplasty (126, 10.5%) with or without concomitant peripheral intervention, conservative treatment (118, 9.8%), and primary major amputation (30, 2.5%). The primary endpoint of this study was amputation-free survival (AFS). The Society of Vascular Surgery's suggested objective performance goal (OPG) for AFS (71%) was used as the effectiveness criterion. Multivariable regression methods were employed to identify variables that influenced the treatment selection and AFS after each treatment; results are presented as the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

The 12-month AFS estimates following endovascular therapy, bypass grafting, femoral patchplasty, and conservative treatment were 75%, 72%, 73%, and 72%, respectively. Factors influencing treatment choice were age, chronic kidney disease (CKD), diabetes, smoking, prior vascular procedures in the index leg, TransAtlantic Inter-Society Consensus II C/D lesions, and absence of runoff vessels. Cox regression analysis identified CKD (HR 2.07, 95% CI 1.26 to 3.41, p=0.004), the use of a prosthetic bypass conduit (HR 1.97, 95% CI 1.23 to 3.14, p=0.004), and previous vascular intervention in the index limb (HR 1.52, 95% CI 0.94 to 2.43, p=0.085) as independent risk factors for diminished AFS after bypass surgery. CKD (HR 1.47, 95% CI 1.09 to 1.99, p=0.012) and Rutherford category 6 (HR 1.81, 95% CI 1.30 to 2.52, p<0.001) compromised the performance of endovascular revascularization.

CONCLUSION

CRITISCH registry data revealed that all first-line treatment strategies selected and indicated by the treating physicians met the suggested OPGs. CKD was an important determinant of patient prognosis after treatment regardless of the revascularization method.

Robust Revascularization in Models of Limb Ischemia Using a Clinically Translatable Human Stem Cell-Derived Endothelial Cell Product

Pluripotent stem cell-derived differentiated endothelial cells offer high potential in regenerative medicine in the cardiovascular system. With the aim of translating the use of a human stem cell-derived endothelial cell product (hESC-ECP) for treatment of critical limb ischemia (CLI) in man, we report a good manufacturing practice (GMP)-compatible protocol and detailed cell tracking and efficacy data in multiple preclinical models. The clinical-grade cell line RC11 was used to generate hESC-ECP, which was identified as mostly endothelial (60% CD31⁺/CD144⁺), with the remainder of the subset expressing various pericyte/mesenchymal stem cell markers. Cell tracking using MRI, PET, and qPCR in a murine model of limb ischemia demonstrated that hESC-ECP was detectable up to day 7 following injection. Efficacy in several murine models of limb ischemia (immunocompromised/immunocompetent mice and mice with either type I/II diabetes mellitus) demonstrated significantly increased blood perfusion and capillary density. Overall, we demonstrate a GMP-compatible hESC-ECP that improved ischemic limb perfusion and increased local angiogenesis without engraftment, paving the way for translation of this therapy.

Long-Term Clinical Outcomes Survey of Bone Marrow-Derived Cell Therapy in Critical Limb Ischemia in Japan

BACKGROUND

The Therapeutic Angiogenesis by Cell Transplantation (TACT) trial demonstrated the efficacy and safety of autologous bone marrow-derived mononuclear cells (BM-MNCs) in patients with critical limb ischemia (CLI). The present study aimed to assess the long-term clinical outcomes of therapeutic angiogenesis using autologous BM-MNC implantation under advanced medical treatment in Japan.

METHODS AND RESULTS

The study was retrospective, observational, and non-controlled. We assessed no-option CLI patients who had BM-MNC implantation performed in 10 institutes. Overall survival (OS), major amputation-free (MAF), and amputation-free survival (AFS) rates were primary endpoints of this study. The median follow-up duration was 31.7 months. The 10-year OS rate was 46.6% in patients with arteriosclerosis obliterans (ASO) (n=168), 90.5% in patients with thromboangiitis obliterans (TAO) (n=108), and 67.6% in patients with collagen disease-associated vasculitis (CDV) (n=69). The 10-year MAF rate was 70.1%, 87.9%, and 90.9%, respectively. The 10-year AFS rate was 37.8%, 80.9%, and 61.2%, respectively. Major adverse cardiovascular events occurred in 6.0% of patients with ASO, 1.9% of patients with TAO, and no patients with CDV.

CONCLUSIONS

Therapeutic angiogenesis using autologous BM-MNC implantation may be feasible and safe in patients with no-option CLI, particularly those with CLI caused by TAO or CDV.

Testing the sympathetic nervous system of the foot has a high predictive value for early amputation in patients with diabetes with a neuroischemic ulcer

OBJECTIVE

There is evidence from the literature that dysfunctionality of the sympathetic nervous system of the foot with subsequent loss of local autoregulation could be a predictor of early amputation in patients with diabetes with a neuroischemic ulcer. To confirm this we tested the functionality of the sympathetic nervous system in the foot in a consecutive group of 31 patients with diabetes with critical limb ischemia and non-healing neuroischemic ulcer.

RESEARCH DESIGN AND METHODS

Prospective cohort with retrospective analysis after 12 months of routinely acquired clinical data. All patients in the study group underwent angiography of the foot as part of a routine angioplasty procedure. Primary study endpoint was lower extremity amputation-free survival at 12 months. Because of the study design no other endpoints could be analyzed. The functionality of the sympathetic nervous system was tested with perfusion angiography.

RESULTS

Thirty-one patients were followed for 12 months. The Capillary Resistance Index (CRI) was used to measure the response of the sympathetic nervous system. CRI≥0.9 is the cut-off point for a non-responsive sympathetic nervous system. All patients (n=11) with a CRI≥0.9 underwent a major amputation before 12 months. Of all patients with a CRI only 15% underwent major amputation. The positive predictive value for major amputation before 12 months for patients with a CRI ≥ 0.9 was 100%.

CONCLUSIONS

A non-responsive sympathetic nervous system of the foot is a strong predictor of early major amputation (log rank p<0.001; HR 14.22; 95% CI 3.64 to 55.51).

The Use of the Profunda Femoral Artery as the Sole Target Vessel to Bypass Aortoiliac Disease in Patients with Critical Limb Ischemia and Concomitant Unreconstructable Infrainguinal Disease

BACKGROUND

Critical limb ischemia (CLI) often results from multilevel occlusive disease. There are occasions where a patent profunda femoral artery (PFA) is the only target artery that can be used as outflow during reconstruction to bypass aortoiliac disease (AOID), with no further option for infrainguinal revascularization. We aim to report results of the use of PFA as the sole target vessel for the treatment of these patients.

METHODS

This is a retrospective, single-center study including CLI patients treated during 36 months. All procedures were included regardless of inflow site. The outcomes examined were hemodynamic improvement, clinical status change, amputation-free and overall survival, and patency of the prosthesis. Univariate analysis was performed to identify possible predictors of adverse outcomes.

RESULTS

Twenty-three patients and 27 limbs were included (2 female, mean age 70.6). Sixteen limbs presented rest pain and 11 tissue loss. Inflow was obtained from the axillary (n = 9), contralateral femoral (n = 8), abdominal aorta (n = 2), thoracic aorta (n = 1), ipsilateral external iliac (n = 2), and contralateral external iliac artery (n = 1). Immediately postoperatively ankle-brachial index significantly increased from 0.15 (0-0.5) to 0.50 (0.25-0.9), (P-value < 0.001). Twenty-four limbs presented clinical improvement (3 minimally, 18 moderately, and 3 markedly improved) and 3 presented no change. During a mean follow-up of 15.8 (2-36) months, we recorded 4 deaths and 4 major amputations. Mean predicted overall survival and amputation-free survival were 29.8 (95% confidence interval [CI] 24.5-35.1) and 26.5 months (95% CI 21.1-31.8), respectively. Predicted primary patency was 76% at 3 years. Univariate analysis revealed significant associations only between bypass patency and limp loss (P-value = 0.021).

CONCLUSIONS

In the presence of CLI due to AOID and unreconstructable infrainguinal disease, the use of PFA as the sole target vessel during bypass is associated with significant rates of clinical improvement and limb salvage.

Surgical and endovascular venous arterialization for treatment of critical limb ischaemia

Patients with critical limb ischaemia have a poor life expectancy. Aggressive revascularization is accepted in order to preserve their independence in the final phase of their lives. Bypass surgery and more recently endovascular interventions with angioplasty and stenting have become the treatment of choice to prevent amputation and to resolve pain. However, as many as 20 % of patients with critical limb ischaemia are unsuitable candidates for a vascular intervention because of extensive occlusions of outflow in the crural and pedal vessels. Such "no-option critical limb ischaemia" may be treated with venous arterialization. In the present review, we discuss the history of the venous arterialization procedure, the mechanisms, the different techniques, and complications of venous arterialization.

Midterm Outcomes From a Pilot Study of Percutaneous Deep Vein Arterialization for the Treatment of No-Option Critical Limb Ischemia

PURPOSE

To report the initial clinical experience with percutaneous deep vein arterialization (PDVA) to treat critical limb ischemia (CLI) via the creation of an arteriovenous fistula.

METHODS

Seven patients (median age 85 years; 5 women) with CLI and no traditional endovascular or surgical revascularization options (no-option CLI) were recruited in a pilot study to determine the safety of PDVA. All patients were diabetic; 4 had Rutherford category 6 ischemia. Six were classified at high risk of amputation based on the Society for Vascular Surgery WIfI (wound, ischemia, and foot infection) classification. The primary safety endpoints were major adverse limb events and major adverse coronary events through 30 days and serious adverse events through 6 months. Secondary objectives included clinical efficacy based on outcome measures including thermal measurement, transcutaneous partial pressure of oxygen (TcPO₂), clinical improvement at 6 months, and wound healing.

RESULTS

The primary safety endpoints were achieved in 100% of patients, with no deaths, above-the-ankle amputations, or major reinterventions at 30 days. The technical success rate was 100%. Two myocardial infarctions occurred within 30 days, each with minor clinical consequences. All patients demonstrated symptomatic improvement with formation of granulation tissue, resolution of rest pain, or both. Complete wound healing was achieved in 4 of 7 patients and 5 of 7 patients at 6 and 12 months, respectively, with a median healing time of 4.6 months (95% confidence interval 84-192). Median postprocedure peak TcPO₂ was 61 mm Hg compared to a preprocedure level of 8 mm Hg (p=0.046). At the time of wound healing, 4 of 5 of patients achieved TcPO₂ levels of >40 mm Hg. There were 2 major amputations, 1 above the knee after PDVA thrombosis and 1 below the knee for infection. Three patients died of causes unrelated to the procedure or study device at 6, 7, and 8 months, respectively. Limb salvage was 71% at 12 months.

CONCLUSION

PDVA is an innovative approach for treating no-option CLI and represents an alternative option for the "desert foot," potentially avoiding major amputation. Our results demonstrate its safety and feasibility, with promising early clinical results in this small cohort.

Long-Term Follow-up of the PADI Trial: Percutaneous Transluminal Angioplasty Versus Drug-Eluting Stents for Infrapopliteal Lesions in Critical Limb Ischemia

BACKGROUND

Clinical outcomes reported after treatment of infrapopliteal lesions with drug-eluting stents (DESs) have been more favorable compared with percutaneous transluminal angioplasty with a bailout bare metal stent (PTA-BMS) through midterm follow-up in patients with critical limb ischemia. In the present study, long-term results of treatment of infrapopliteal lesions with DESs are presented.

METHODS AND RESULTS

Adults with critical limb ischemia (Rutherford category ≥4) and infrapopliteal lesions were randomized to receive PTA-BMS or DESs with paclitaxel. Long-term follow-up consisted of annual assessments up to 5 years after treatment or until a clinical end point was reached. Clinical end points were major amputation (above ankle level), infrapopliteal surgical or endovascular reintervention, and death. Preserved primary patency (≤50% restenosis) of treated lesions was an additional morphological end point, assessed by duplex sonography. In total, 74 limbs (73 patients) were treated with DESs and 66 limbs (64 patients) were treated with PTA-BMS. The estimated 5-year major amputation rate was lower in the DES arm (19.3% versus 34.0% for PTA-BMS; P=0.091). The 5-year rates of amputation- and event-free survival (survival free from major amputation or reintervention) were significantly higher in the DES arm compared with PTA-BMS (31.8% versus 20.4%, P=0.043; and 26.2% versus 15.3%, P=0.041, respectively). Survival rates were comparable. The limited available morphological results showed higher preserved patency rates after DESs than after PTA-BMS at 1, 3, and 4 years of follow-up.

CONCLUSIONS

Both clinical and morphological long-term results after treatment of infrapopliteal lesions in patients with critical limb ischemia are improved with DES compared with PTA-BMS.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00471289.

Phase Ib Safety, Two-Dose Study of MultiGeneAngio in Patients with Chronic Critical Limb Ischemia

Critical limb ischemia (CLI) is the most severe presentation of peripheral arterial disease. We developed cell-based therapy entailing intra-arterial injection of autologous venous endothelial cells (ECs) modified to express angiopoietin 1, combined with autologous venous smooth muscle cells (SMCs) modified to express vascular endothelial growth factor. This combination promoted arteriogenesis in animal models and was safe in patients with limiting claudication. In an open-label, phase Ib study, we assessed the safety and efficacy of this therapy in CLI patients who failed or were unsuitable for surgery or intravascular intervention. Of 23 patients enrolled, 18 with rest pain or non-healing ulcers (Rutherford categories 4 and 5) were treated according to protocol, and 5 with significant tissue loss (Rutherford 6) were treated under compassionate treatment. Patients were assigned randomly to receive 1 × 10⁷ or 5 × 10⁷ (EC-to-SMC ratio, 1:1) of the cell combination. One-year amputation-free survival rate was 72% (13/18) for Rutherford 4 and 5 patients; all 5 patients with Rutherford 6 underwent amputation. Of the 12 with unhealing ulcers at dosing, 6 had complete healing and 2 others had >66% reduction in ulcer size. Outcomes did not differ between the dose groups. No severe adverse events were observed related to the therapy.

Interdisciplinary treatment of diabetic foot wounds in the elderly: Low risk of amputations and mortality and good chance of being mobile with good quality of life

AIMS

A major proportion of patients with diabetic foot syndrome are older than 65 years. Little is known about outcomes of these elderly patients.

METHODS

We analysed 245 treatment cases in an observational single-centre study for comorbidities and outcomes over a 6-month period.

RESULTS

In all, 122 patients had peripheral arterial disease which was significantly increasing with age (n = 245, df = 1, χ² = 23.06, p ⩽ 0.0001). Increasing age correlated positively with decreasing rate of revascularisations (n = 122, df = 1, χ² = 4.23, p = 0.039). In total, 23 (9.3%) patients died in the observation period. In-hospital mortality was 2.8%, percentage of major amputations 2.8%. In the invasively treated subgroup, 13 out of 67 patients died within the observation period. Death after revascularisation was independent of age (n = 67, df = 1, χ² = 2.05, p = 0.153). Mobility decreased in the whole study group with increasing age. The risk of decrease with age was not influenced by revascularisation status.

CONCLUSION

With careful interdisciplinary evaluation, elderly patients with diabetic foot syndrome can be treated with favourable outcome. Mobility before and after treatment deserves more attention as a predictor of treatment success and outcome parameter.

Not All Patients with Critical Limb Ischaemia Require Revascularisation

OBJECTIVES

International guidelines recommend revascularisation as the preferred treatment for patients with critical limb ischaemia (CLI). Most contemporary research focuses on the outcome of invasive procedures for CLI, but little is known about the outcome of conservative management. Amputation free survival (AFS) and overall survival (OS) was investigated in patients with CLI who did or did not receive revascularisation, and characteristics associated with clinical outcomes were explored.

METHODS

This was a retrospective cohort study of consecutive patients with chronic CLI between 2010 and 2014 in a Dutch university hospital. CLI was defined as the presence of ischaemic rest pain or tissue loss in conjunction with an absolute systolic ankle pressure < 50 mmHg or a toe pressure < 30 mmHg. Patients were divided into invasive (revascularisation within 6 weeks), deferred invasive (revascularisation after 6 weeks), or permanently conservative treatment groups. Univariable and multivariable survival analyses were used to identify factors associated with AFS and OS.

RESULTS

The majority (66.7%; N = 96) of the identified 144 patients with CLI (mean age 71.2 years; median follow-up 99 weeks) underwent revascularisation within 6 weeks of diagnosis. Deferred invasive treatment was provided in 18.1% (N = 26) patients and 22 patients (15.3%) were treated permanently conservatively. AFS and OS did not differ significantly between the three groups (Breslow-Wilcoxon p = .16 for AFS and p = .09 for OS). Age, chronic obstructive pulmonary disease (COPD), and heart disease were significant independent predictors of AFS. Age, COPD, and hypertension were significant independent predictors of OS. Treatment was not a significant predictor of either AFS or OS.

CONCLUSIONS

Not all patients with CLI require revascularisation to achieve an AFS that is similar to patients undergoing revascularisation, although the efficacy of conservative versus invasive treatment in CLI patients is still unclear. Further prospective studies should determine subgroups of patients in whom revascularisation may be omitted.

Prognostic factor of the two-year mortality after revascularization in patients with critical limb ischemia

Purposes

The aim of this study was to evaluate the risk factors for the two-year survival after revascularization of critical limb ischemia.

Methods

Between 2008 and 2012, 142 patients underwent revascularization. A retrospective analysis was performed to measure the risk factor.

Results

A total 85 patients underwent surgical revascularization, 31 patients underwent endovascular therapy while 26 patients underwent hybrid therapy. By multivariate analysis, the following variables were considered to be risk factors: ejection fraction <50 % (HR, 3.14; 95% CI, 1.22–7.95; P = 0.02), serum albumin level <2.5 g/dL (HR, 3.45; 95% CI, 1.01–11.7; P = 0.04) and nonambulatory status (HR, 4.11; 95% CI, 1.79–9.70; P < 0.01). The two-year survival rate of the patients with no risk factors was 85.5%, while the patients with at least one risk factor had an unfavorable prognosis (one; 56.7%, two; 45.4%).

Conclusions

The nonambulatory status, serum albumin level <2.5 g/dL and ejection fraction <50% were the risk factors for the two-year mortality after revascularization in critical limb ischemia patients. These risk factors may be useful for the treatment strategy of critical limb ischemia patients.

Design and Rationale of the Best Endovascular Versus Best Surgical Therapy for Patients With Critical Limb Ischemia (BEST-CLI) Trial

BACKGROUND

Critical limb ischemia (CLI) is increasing in prevalence, and remains a significant source of mortality and limb loss. The decision to recommend surgical or endovascular revascularization for patients who are candidates for both varies significantly among providers and is driven more by individual preference than scientific evidence.

METHODS AND RESULTS

The Best Endovascular Versus Best Surgical Therapy for Patients With Critical Limb Ischemia (BEST-CLI) Trial is a prospective, randomized, multidisciplinary, controlled, superiority trial designed to compare treatment efficacy, functional outcomes, quality of life, and cost in patients undergoing best endovascular or best open surgical revascularization. Approximately 140 clinical sites in the United States and Canada will enroll 2100 patients with CLI who are candidates for both treatment options. A pragmatic trial design requires consensus on patient eligibility by at least 2 investigators, but leaves the choice of specific procedural strategy within the assigned revascularization approach to the individual treating investigator. Patients with suitable single-segment of saphenous vein available for potential bypass will be randomized within Cohort 1 (n=1620), while patients without will be randomized within Cohort 2 (n=480). The primary efficacy end point of the trial is Major Adverse Limb Event-Free Survival. Key secondary end points include Re-intervention and Amputation-Free-Survival and Amputation Free-Survival.

CONCLUSIONS

The BEST-CLI trial is the first randomized controlled trial comparing endovascular therapy to open surgical bypass in patients with CLI to be carried out in North America. This landmark comparative effectiveness trial aims to provide Level I data to clarify the appropriate role for both treatment strategies and help define an evidence-based standard of care for this challenging patient population.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02060630.

Preventing and treating foot complications associated with diabetes mellitus

Diabetes mellitus is associated with a series of macrovascular and microvascular changes that can manifest as a wide range of complications. Foot ulcerations affect ∼2-4% of patients with diabetes mellitus. Risk factors for foot lesions include peripheral and autonomic neuropathy, vascular disease and previous foot ulceration, as well as other microvascular complications, such as retinopathy and end-stage renal disease. Ulceration is the result of a combination of components that together lead to tissue breakdown. The most frequently occurring causal pathways to the development of foot ulcers include peripheral neuropathy and vascular disease, foot deformity or trauma. Peripheral vascular disease is often not diagnosed in patients with diabetes mellitus until tissue loss is evident, usually in the form of a nonhealing ulcer. Identification of patients with diabetes mellitus who are at high risk of ulceration is important and can be achieved via annual foot screening with subsequent multidisciplinary foot-care interventions. Understanding the factors that place patients with diabetes mellitus at high risk of ulceration, together with an appreciation of the links between different aspects of the disease process, is essential to the prevention and management of diabetic foot complications.