Chronic Limb-threatening Ischemia Patients Research Articles

Comparison of endovascular therapies for chronic limb-threatening ischemia and claudication

ObjectiveAnalysis of regional data from the Vascular Quality Initiative (VQI) suggested improved survival for patients undergoing stent placement compared with balloon angioplasty and atherectomy. Using national data from the VQI linked to Medicare claims data through the Vascular Implant Surveillance and Interventional Outcomes Network program, this study aimed to compare the rates of mortality, reintervention, and amputation after endovascular interventions (atherectomy, stenting, and balloon angioplasty) for two separate cohorts: patients with chronic limb-threatening ischemia (CLTI) and patients with claudication. MethodsThis was a secondary data analysis of Society for Vascular Surgery National VQI data linked to Medicare claims, between October 2016 and December 2019. Patients aged ≥65 years with symptoms of claudication or CLTI and a diagnosis of occlusive disease were included. Urgent or emergent interventions or those with concurrent procedures (endarterectomy, bypass, or bilateral intervention) were excluded. Interventions were grouped into (1) balloon angioplasty only; (2) stent (with or without balloon angioplasty); or (3) atherectomy (alone, with or without stent, with or without balloon angioplasty). Propensity score-matched cohorts were constructed to conduct pairwise intervention comparisons of mortality, reintervention, and amputation rates. Multivariable logistic regression was used to derive propensity scores for each patient. Kaplan-Meier estimates and Cox proportional hazards ratios (HRs) (95% confidence interval [CI]) analyses were performed. ResultsA total of 9785 (2665 claudication, 7120 CLTI) eligible patients were identified. After propensity score matching for the CLTI group, 2826, 3608, and 2796 pairs of cases were used to compare balloon angioplasty vs atherectomy, balloon angioplasty vs stent, and stent vs atherectomy, respectively. No statistically significant difference in mortality was observed among all interventions. However, atherectomy was associated with a significant increase in reintervention rate compared with balloon angioplasty (HR, 1.22; 95% CI, 1.06-1.39; P = .01) and compared with stenting (HR, 1.27; 95% CI, 1.10-1.46; P < .01) within the first year after the index procedure. Of note, both atherectomy (HR, 0.82; 95% CI, 0.68-0.98; P < .05) and stenting (HR, 0.76; 95% CI, 0.64-0.90; P < .01) showed lower rates of major amputation when compared with balloon angioplasty within 1 year after the index procedure. In the claudication group, there were no significant differences observed among interventions for peripheral arterial disease for mortality, reintervention, or amputation rates. ConclusionsFurther studies are needed to identify appropriate indications for atherectomy, because there may be a subset of patients with CLTI who benefit from this therapy with respect to amputation rates. Until then, caution should be exercised when using atherectomy because it is also associated with higher reintervention rates.

Endovascular and Surgical Venous Arterialization for No-Option Patients With Chronic Limb-Threatening Ischemia: A Systematic Review and Meta-Analysis.

Chronic limb-threatening ischemia (CLTI) is known for its high rates of major amputation and mortality. Conventional revascularization techniques often fail in CLTI patients due to the heavily diseased arteries. Foot vein arterialization (FVA) has been proposed as an alternative technique to provide arterial blood to the foot by using the disease-free venous bed. This systematic review and meta-analysis aimed to determine outcomes of surgical FVA (sFVA) and percutaneous FVA (pFVA) at 6 and 12 months post-procedure. PubMed, Scopus, Web of Science, and the Cochrane Library databases were searched to identify papers reporting clinical outcomes of sFVA and pFVA published between January 1966 and March 2023. Databases were searched for eligible studies. A meta-analysis was performed to evaluate the limb salvage rate, overall survival rate, and wound healing rate at 6 and 12 months. A total of 27 studies were included, with 753 patients and 793 limbs. Of the included studies, 16 analyzed the sFVA technique and 11 the pFVA technique. Of the included patients, 86.3% were Rutherford 5/6 in the sFVA group versus 98.4% in the pFVA group. The pooled limb salvage rate at 6 and 12 months was 78.1% and 74.1% in the sFVA group and 81.7% and 78.6% in the pFVA group, respectively. Wound healing rates were not reported in the sFVA group. In the pFVA group, the pooled wound healing rates were 48.1% and 64.5% at 6 and 12 months, respectively. This study showed promising results after FVA among a large population of CLTI patients. In high-risk patients, pFVA is a feasible option with favorable limb salvage and wound healing rates.

Percutaneous Deep Venous Arterialization for Limb Salvage in No Option Patients with Chronic Limb-Threatening Ischemia.

An endovascular approach is often considered the first line treatment option for lower limb chronic limb-threatening ischemia (CLTI), which is defined by the presence of ischemic rest pain and severe tissue loss, such as ulcers or gangrene. Although the technical success rate of endovascular revascularization is high, in specific patients with advanced infrapopliteal disease and the absence of run-off tibial vessels, the so-called 'desert foot', the chance of successful endovascular revascularization is minimal. In order to avoid primary amputation, several treatment options are currently being investigated, including gene therapy and deep venous arterialization. This review focuses on the percutaneous deep venous arterialization technique as a promising, minimally invasive treatment option for limb salvage in CLTI patients presenting with a 'desert foot'.

Minor amputation after revascularization in chronic limb-threatening ischemia: What is the optimal timing?

Patients with chronic limb-threatening ischemia (CLTI) have a high risk of lower limb amputation and loss of walking independence. Minor amputations play a key role in ensuring walking independence and they represent a challenge in terms of timing and level for vascular surgeons. A major cause of re-amputation is a defect in wound healing and a possible predictor of re-amputation for non-healing wounds could be the incorrect timing of minor amputation after revascularization. The lack of evidence in the literature leads to a wide variability of choices in clinical practice. The purpose of this study was to try to find the optimal timing analysing the risk of re-amputation in CLTI patients who have undergone successful revascularization and minor amputation focussing on timing of minor amputation. We conducted a single centre retrospective analysis on a cohort of 151 patients consecutively admitted to our hospital for CLTI (Rutherford 5) between January 2014 and April 2022. All the enrolled patients underwent successful revascularization of lower limbs and a minor amputation for dry acral necrosis. The characteristics of the patients and the revascularization procedures were collected and analysed. Patients were divided into two groups based on the timing of minor amputation performed before (group 1) or after the day (group 2) that best predicts the risk of re-amputation according to a Receiver Operating Characteristic (ROC) curve analysis. The primary outcome of this study was the risk of re-amputation during the first 60days of follow-up after a primary minor amputation, with revascularization still effective. The impact of the timing of minor amputation after revascularization, the type of revascularization and the presence of risk factors known to prolong the wound healing process were evaluated in a uni- and multi-variable logistic regression model. Systemic hypertension, and type of revascularization (i.e. open vs endovascular) were independent predictors of the risk of re-amputation at 60days (HR 4.26, 95% CI 1.30-14.04, p = .017 and HR 2.35, 95% CI 1.16-4.78, p = .018, respectively). Moreover, time ≤14days between revascularization and first amputation was associate with a clear, albeit not statistically significant, trend toward increased risk of re-amputation (HR 2.09, 95% CI 0.97-4.51, p = .06). In a cohort of patients who underwent a successful revascularization for CLTI and a minor amputation for dry gangrene in the first 14 days after revascularization, a higher -although not significant-risk of re-amputation was reported. In this cohort of patients, a delayed demolitive procedure should be considered to allow better tissue perfusion and to reduce the risk of re-amputation.

Abstract 18426: Secreted Frizzled-Related Protein 1 Mediates Adipogenic Differentiation of Vascular Cell Adhesion Protein 1 Fibroadipogenic Progenitors in the Ischemic Limb

Introduction: Chronic limb threatening ischemia (CLTI) patients display a skeletal muscle myopathy that is hallmarked by fatty infiltration. The replacement of functional muscle fibers with adipocytes impairs ambulatory function and is associated with poor clinical outcomes. The cell type responsible for fatty infiltration is a mesenchymal stromal cellular population, term fibroadipogenic progenitors (FAPs). We previously demonstrated that Vcam1+ FAPs represent a sub-population with increased adipogenic potential. However, the molecular mechanisms which govern Vcam1+ FAP mediated adipogenesis remain unknown. Herein, we sought to identify the intracellular mechanisms that drive Vcam1+ FAPs into an adipogenic cellular fate. Methods: We used single cell and bulk RNA-sequencing to identify Sfrp1 as an enriched gene in Vcam1+ FAPs. Next, to determine the sufficiency and necessity of Sfrp1, we overexpress Sfrp1 with a recombinant protein and inhibit Sfrp1 with a siRNA and assess adipogenesis. To assess the clinical significance of this FAP subpopulation, we apply single-cell RNA sequencing to CLTI patients. Results: We show in a CLTI murine model that Vcam1+ FAPs are enriched in Sfrp1. Next, we demonstrate that Sfrp1 is both sufficient and necessary for the differentiation of Vcam1+ FAPs into adipocytes. Finally, we demonstrate that human CLTI patients also have a pathologic FAP population that is enriched in Vcam1 and Sfrp1Conclusions: Our results reveal a novel mechanism for fatty infiltration, a histologic hallmark of CLTI patients, in the ischemic limb. We also validate the clinical significance of Vcam1+ Sfrp1+ FAPs by demonstrating the presence of this population in human CLTI patients. This work lays the foundation for future studies aimed at inhibiting fatty infiltration and promoting skeletal muscle regeneration in CLTI patients.

Abstract 17944: Process Mapping Care of Patients With Lower Extremity Wounds Due to Chronic Limb Threatening Ischemia

Background: The care experience for patients with wounds due to chronic limb threatening ischemia (CLTI) is rarely understood. Quality improvement programs frequently fail to recognize the entire process involved in accessing care. We developed a process map for stakeholders to guide quality improvement for CLTI patients. Methods: We recruited a team of stakeholders, including nurses, providers, coordinators, and patients, and met through iterative meetings to create a process map. We categorized barriers, identified actors, and estimated wait times. Based on information gathered, targeted solutions to improve care were developed. Results: We mapped 2 pathways, inpatient hospitalization and outpatient evaluation, for CLTI patients seeking care. Within these 2 paths, we identified 25 action steps with 15 decision points. We identified a total of 105 barriers to patients accessing care in each pathway. These were mapped into 9 categories grouped into multiple patient factors, health systems resources, insurance, communications, and waiting. We also identified 40 actors whose role in the process could create barriers within the process, including family, translators, social services, insurance. Finally, we grouped solutions into 4 categories. Overall, the shortest time to treatment was mapped as 8 weeks with expedited care to over 1 year with care provided solely in clinic. Conclusion: Process mapping highlights the great lengths patients endure to get treatment as well as specific opportunities for improving care between systems, providers, patients, and families. This work should serve as the foundation for quality improvement programs for patients with CLTI.

Successful Revascularization, Angiosome Concept, and Multivessel Revascularization: Effects on Wound Healing: An Asian Perspective.

Endovascular treatment for revascularization in patients with chronic limb-threatening ischemia (CLTI), which is commonly found in patients with diabetes mellitus demonstrates a variable result of vessel patency, wound healing rate, and limb salvage rate. The angiosome concept has been adopted to determine the best target arterial path (TAP) for revascularization for wound healing in CLTI patients. Recent publications demonstrated the benefit of angiosome-targeted revascularization to guide the endovascular treatment in patients CLTI. The best TAP under angiosome concept by direct revascularization with at least 2 of 3 below-the-knee arteries runoff to restore in-line pulsatile blood flow to the ischemic tissue shows the best patency and high rate of wound healing. However, the clinical evidence and application of the angiosome concept in daily practice are difficult and not well established. The vascular territories, collateral vessel, wound area, and locations which associated with angiosome are varied. This article review aims to summarize the concept of angiosome-targeted revascularization and multivessel revascularization for application to the real-world practice under the evidence-based data.

Inflammation Is a Histological Characteristic of Skeletal Muscle in Chronic Limb Threatening Ischemia

The loss of skeletal muscle is a prognostic factor in several diseases including in patients with chronic limb threatening ischemia (CLTI). Patients with CLTI also have a lower skeletal mass and area when compared to those with claudication. However, there are no currently available data regarding the histological characteristics of core muscles in patients with CLTI. This study aims to determine the differences in core skeletal muscles between patients with claudication and those with CLTI. The second aim is to evaluate the differences in myokines, which are molecules secreted by skeletal muscle, between patients with claudication and those with CLTI. An observational, prospective study was conducted from January 2018 to July 2022 involving consecutive patients with peripheral arterial disease (PAD). The clinical characteristics were registered. In PAD patients with surgical indication for common femoral artery approach, samples of sartorius skeletal muscle (and not from the limb muscles directly involved in the ischemic process) were collected. The samples were submitted to histological characterization on hematoxylin-eosin and to immunohistochemical analysis to detect CD45+ leukocytes and CD163+ macrophages. The extent of the inflammatory cells (leukocytes and macrophages) was semiquantitatively assessed using a 0-to-4 grade scale as follows: absent (0†), mild (†), moderate (††), severe (†††), and very severe (††††). Serum levels of myokines: irisin, myostatin, IL-8, and lL-6 were determined with multiplex bead-based immunoassay. 119 patients (mean age: 67.58±9.60years old, 79.80% males) 64 with claudication and 54 with CLTI were enrolled in the study. No differences were registered between patients with claudication and those with CLTI on age, gender, cardiovascular risk factors, and medication, except on smoking habits. There was a significantly higher prevalence of smokers and a higher smoking load in the claudication group. Samples of sartorius skeletal muscle from 40 patients (14 with claudication and 26 with CLTI) were submitted to histological analysis. No differences were found in skeletal muscle fibers preservation, trauma, or hemorrhage (on hematoxylin-eosin staining). However, in the immunohistochemistry study, we found more inflammatory cells CD45+ leukocytes in patients with CLTI when compared to those with claudication [CD45+≥moderate (††): claudication (n=14): 4; 28.57%; CLTI (n=25): 16; 64.00%; P=0.034]. Patients with CLTI also had higher tissue levels of CD163+ macrophages, but this difference was not significant [CD163+≥moderate (††): claudication (n=13): 7; 53.85%; CLTI (n=27): 21; 77.78%; P=0.122]. The serum levels of the myokines, irisin, and myostatin were below the lower limit of detection, in the majority of patients, so no valid results were obtained. However, patients with CLTI had a higher serum level of Interleukin (IL)-6 and IL-8. CLTI patients exhibit increased quantities of leukocytes in their sartorius muscle, as well as elevated serum levels of myokines IL-8 and IL-6. Inflamed skeletal muscle can contribute to the loss of muscle mass and account for the lower density of skeletal muscle observed in CLTI. Additionally, inflamed skeletal muscle may contribute to the development of systemic inflammation through the secretion of pro-inflammatory cytokines into the systemic circulation. Halting the inflammatory process could eventually improve the prognosis of CLTI patients.

Drug-Coated Balloon Angioplasty of Infrapopliteal Lesions in Chronic Limb-Threatening Ischemia: Six-month Outcomes of PRIME-WIFI.

To evaluate 6-month outcomes of drug-coated balloon (DCB) angioplasty of infrapopliteal lesions in patients with chronic limb-threatening ischemia (CLTI). We analyzed 6-month follow-up data from the 10-center PRIME-WIFI prospective registry on 300 consecutive patients (33.000% female) with CLTI who underwent DCB angioplasty for infrapopliteal arterial lesions. The primary outcome was freedom from major adverse event (MAE), a composite of major amputation, all-cause death, and clinically-driven target limb reintervention (CD-TLR). Secondary outcomes included amputation-free survival (AFS), freedom from each primary outcome component, primary sustained clinical improvement, and quality of life (QOL) score. Independent risk factors of MAE were determined using Cox proportional hazards regression analysis. A total of 409 infrapopliteal lesions in 312 limbs were treated with DCB, with 54.167% of the limbs being treated for isolated infrapopliteal lesions. By Kaplan-Meier analysis, at 6 months post- procedure (follow-up rate, 85.000%), freedom from MAE was 86.353%; AFS was 90.318%; and freedom from major amputation, all-cause death, and CD-TLR were 96.429%, 93.480%, and 95.079%, respectively. At 6-month follow-up, 83.590% of patients showed primary sustained clinical improvement, and QOL score (4.902±1.388) improved compared with that before procedure (2.327±1.109; p<0.001). Chronic renal insufficiency, chronic obstructive pulmonary disease, Rutherford grade, and postoperative infrapopliteal runoff score were independent risk factors for MAE within 6 months. In CLTI, DCB angioplasty of infrapopliteal lesions yields acceptable early efficacy and safety. This study evaluated the 6-month outcomes of DCB angioplasty in infrapopliteal lesions in CLTI patients by analyzing multicenter prospective data, showing that infrapopliteal DCB angioplasty can be performed with acceptable freedom from MAE rate, amputation-free survival rate, freedom from major amputation rate, survival rate, and freedom from CD-TLR rate. No patient experienced DCB-related intraoperative distal embolism. Chronic renal insufficiency, chronic obstructive pulmonary disease, Rutherford grade and postoperative infrapopliteal runoff score were independent risk factors for MAE within 6 months. Comparative real-world studies are needed.

Risk Analysis and Clinical Outcomes in Chronic Limb-threatening Ischemia Patients with Surgical Site Infection after Distal Bypass

A recent randomized control study showed that long-term outcomes after surgical revascularization were superior to those after endovascular treatment for cases with chronic limb-threatening ischemia (CLTI) with an appropriate single-segment great saphenous vein. However, surgical site infection (SSI) in CLTI cases after infrapoplital bypass also resulted in a prolonged hospital stay and poor outcomes, including graft disruption. The aim of the current study was to analyze risk factors for SSI in CLTI patients after distal bypass and to compare outcomes in patients with and without SSI. A total of 515 cases that underwent distal bypass at a single center between 2009 and 2022 were analyzed retrospectively. Comparisons were made between patients with and without SSI after distal bypass. The primary end point was limb salvage after distal bypass. Of the 515 cases that underwent distal bypass, 79 (15%) had SSI. The risk factors for SSI were preoperative antibacterial drug use (P=0.001), pedal bypass (P=0.001), and prolonged operation time (≥150min) (P=0.010). The median hospital stay in SSI cases was longer than that in non-SSI cases (P<0.001). Of 515 distal bypasses, 7 (1.3%) bypass grafts ruptured postoperatively due to SSI, and of these 7 cases, 6 ruptured during the day, 5 cases occurred within 1month postoperatively, and 2 patients (29%) are alive without amputation. The mean follow-up period was 34±30months. During follow-up, 62 limbs (SSI cases, 19; non-SSI cases, 43) required major amputation and there were 234 deaths (SSI cases, 46; non-SSI cases, 188). The 1-, 3-, and 5-year limb salvage rates of 82%, 71%, and 62%, respectively, in SSI cases were significantly lower than those in non-SSI cases (P<0.001). The 5-year survival rate of 29% in SSI cases showed a tendency to be lower than that in non-SSI cases (P=0.058). The limb salvage rate in SSI cases was lower than in non-SSI cases after distal bypass. Graft rupture due to SSI occurred at a rate of 1.3% and resulted in poor outcomes in most cases. SSIs adversely affect outcomes and further study is needed to identify methods to avoid SSI following distal bypass.

A substantial number of patients with rest pain, ulceration or gangrene are unable to undergo current non-invasive perfusion testing-Could another modality be utilised?

Rest pain, ulceration and gangrene are hallmark features of chronic limb-threatening ischaemia (CLTI). Wound healing can be challenging, and this is compounded by an inability to measure lower limb perfusion via non-invasive tools such as toe pressure (TP). Novel perfusion tests, such as pedal acceleration time (PAT), may overcome some limitations. This study aimed to quantify the proportion of patients with CLTI that were unable to undergo TP measurement. Over a three-year duration, 344 consecutive patients with CLTI underwent PAT assessment (403 limbs). Overall, 32% of limbs were unable to undergo first toe TP, and 12.9% were unable to undergo first and second toe TP due to forefoot/digit amputation or tissue loss. Inability to measure first toe TP disproportionately impacted CLTI patients with diabetes compared to patients without diabetes (39.6% limbs (106/268); vs. 17% limbs (23/135); p < 0.001). Novel modalities may provide a useful tool for assessing perfusion in CLTI.

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.

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

Twelve-Month Outcomes of Intravascular Lithotripsy for Treatment of Calcified Popliteal and Infrapopliteal Lesions in Patients With Chronic Limb-Threatening Ischemia.

Vessel calcification is estimated to be present in 30% to 50% of patients with peripheral arterial disease (PAD) and is one of the main challenges in endovascular treatment. The popliteal artery is unique compared with other arteries due to its exposure to significant deformation and biomechanical stress during knee motion. Intravascular lithotripsy (IVL) is a novel technique that uses acoustic pressure waves to cause microfractures within the intimal and medial wall calcification. Intravascular lithotripsy is safe in femoropopliteal and infrapopliteal lesions, but follow-up studies are lacking. Therefore, the purpose of this study was to describe the first follow-up outcomes of IVL in popliteal and infrapopliteal arterial disease. This prospective, multicenter cohort study included all patients treated with IVL in the popliteal and infrapopliteal arteries at 4 sites. Standardized follow-up with duplex ultrasonography was scheduled at 6 to 8 weeks and 12 months. The primary safety endpoint was a composite of major adverse events (MAEs) at 30 days. Primary efficacy endpoints were primary patency, limb salvage, and amputation-free survival (AFS) at 12 months. Secondary endpoints were primary-assisted patency and freedom from target lesion revascularization (TLR). Endpoints were distributed for patients with chronic limb-threatening ischemia (CLTI) and intermittent claudication (IC) and estimated using the Kaplan-Meier method. Between April 2021 and March 2023, 29 patients with 30 limbs were treated. Diabetes mellitus (DM) and CLTI were present in 62.1% and 80.0% of patients, respectively. Within the 32 treated lesions, severe calcification was present in 84.4% and bailout stenting was necessary in 12.5% of the lesions. Four MAEs occurred within 30 days: 1 closure device failure, 1 major amputation, and 2 deaths, neither of which was related to the study device. The primary patency, primary-assisted patency, freedom from TLR, limb salvage, and AFS at 12 months were 68.8%, 90.0%, 93.3%, 83.9%, and 57.1% for CLTI patients, respectively. No events occurred in restenosis, re-occlusion, TLR, major amputation, or mortality in patients with IC. This first-ever analysis on follow-up outcomes of IVL in the popliteal and infrapopliteal arteries demonstrated promising safety and efficacy outcomes with a low rate of bailout stenting. Vessel calcification is a common feature in peripheral arterial disease (PAD) and is one of the main challenges in endovascular treatment. The popliteal artery is subjected to biomechanical stress during knee motion, which makes stenting unappealing and often leads to worse clinical outcomes. This study aimed to describe the first follow-up outcomes of IVL in popliteal and infrapopliteal arterial disease. As in line with previous studies, no relevant procedural complications were found and the rate of bail-out stenting was only 12.5%. Moreover, in a complex patient population, this study demonstrated promising safety and efficacy outcomes. The comparison of IVL with angioplasty alone or other vessel preparation devices for popliteal and infrapopliteal arterial disease is warranted.

Treatment Location Variation for Chronic Limb-Threatening Ischemia in Patients With Kidney Failure

IntroductionEnd-stage kidney disease (ESKD) is an established risk factor for chronic limb-threatening ischemia (CLTI). Procedural location for ESKD patients has not been well described. This study aims to examine variation in index procedural location in ESKD versus non-ESKD patients undergoing peripheral vascular intervention for CLTI and identify preoperative risk factors for tibial interventions. MethodsChronic limb-threatening ischemia (CLTI) patients were identified in the Vascular Quality Initiative (VQI) peripheral vascular intervention dataset. Patient demographics and comorbidities were compared between patients with and without ESKD and those undergoing index tibial versus nontibial interventions. A multivariable logistic regression evaluating risk factors for tibial intervention was conducted. ResultsA total of 23,480 procedures were performed on CLTI patients with 13.6% (n = 3154) with ESKD. End-stage kidney disease (ESKD) patients were younger (66.56 ± 11.68 versus 71.66 ± 12.09 y old, P = 0.019), more often Black (40.6 versus 18.6%, P < 0.001), male (61.2 versus 56.5%, P < 0.001), and diabetic (81.8 versus 60.0%, P < 0.001) than non-ESKD patients. Patients undergoing index tibial interventions had higher rates of ESKD (19.4 versus 10.6%, P < 0.001) and diabetes (73.4 versus 57.5%, P < 0.001) and lower rates of smoking (49.9 versus 73.0%, P < 0.001) than patients with nontibial interventions. ESKD (odds ratio (OR) 1.67, 95% confidence interval (CI) 1.52-1.86, P < 0.001), Black race (OR 1.19, 95% CI 1.09-1.30, P < 0.001), and diabetes (OR 1.82, 95% CI 1.71-2.00, P < 0.001) were risk factors for tibial intervention. ConclusionsPatients with ESKD and CLTI have higher rates of diabetes and tibial disease and lower rates of smoking than non-ESKD patients. Tibial disease was associated with ESKD, diabetes, and Black race.

Editor's Choice – Bypass versus Angioplasty for Severe Ischaemia of the Leg (BASIL) Prospective Cohort Study and the Generalisability of the BASIL-2 Randomised Controlled Trial

The Bypass versus Angioplasty in Severe Ischaemia of the Leg-2 (BASIL-2) randomised controlled trial has shown that, in patients with chronic limb threatening ischaemia (CLTI) who require an infrapopliteal (IP) revascularisation a vein bypass (VB) first revascularisation strategy led to a 35% increased risk of major amputation or death when compared with a best endovascular treatment (BET) first revascularisation strategy. The study aims are to place the BASIL-2 trial within the context of the CLTI patient population as a whole, and to investigate the generalisability of the BASIL-2 outcome data. This was an observational, single centre prospective cohort study. Between 24 June 2014 and 31 July 2018, the BASIL Prospective Cohort Study (PCS) was performed which used BASIL-2 trial case record forms to document the characteristics, initial and subsequent management, and outcomes of 471 consecutive CLTI patients admitted to the vascular centre. Ethical approval was obtained, and all patients provided fully informed written consent. Follow up data were censored on 14 December 2022. Of the 238 patients who required an infrainguinal revascularisation, 75 (32%) had either IP bypass (39 patients) or IP BET (36 patients) outside BASIL-2. Seventeen patients were initially randomised to BASIL-2. A further three patients who did not have an IP revascularisation as their initial management were later randomised in BASIL-2. Therefore, 95/471 (20%) of patients had IP revascularisation (16% outside, 4% inside BASIL-2). Differences in amputation free survival, overall survival, and limb salvage between IP bypass and endovascular revascularisation performed outside BASIL-2 were not subject to hypothesis testing due to the small sample size. Reasons for non-randomisation into the trial were numerous, but often due to anatomical and technical considerations. CLTI patients who required an IP revascularisation procedure and were subsequently randomised into BASIL-2 accounted for a small subset of the CLTI population as a whole. For a wide range of patient, limb, anatomic and operational reasons, most patients in this cohort were deemed unsuitable for randomisation in BASIL-2. The results of BASIL-2 should be interpreted in this context.

The Wound Express System, A Potential Treatment for Patients with Ulcers and Non-Operable Arterial Disease: A Pilot Safety Study

Background: Intermittent pneumatic compression (IPC) devices apply intermittent compression to the thigh, which is thought to facilitate wound healing by improving wound perfusion in patients with chronic limb-threatening ischemia and no option for revascularization. Wound Express is an IPC device but its safety and efficacy are currently unclear. In this study, we aimed to determine the safety of the Wound Express IPC system in this high-risk cohort.Methods: This was a prospective, non-controlled, non-randomized pilot safety study. In total, 19 patients were screened for inclusion and 10 were recruited. IPC was applied for 2 hours per day for 12 weeks. The primary endpoint was any treatment-related adverse event in the first 3 months. Secondary endpoints included pain using the visual analogue scale, limb status assessed using the Wound, Ischemia, Foot Infection (WIFi) score and quality of life using the Vascular Quality of Life Questionnaire (VASUQOL) score.Results: Of the 10 patients who were enrolled, eight completed the 12-week course. There were no treatment-related adverse events. One patient died from coronavirus disease 19-related disease and two withdrew for reasons unrelated to treatment. Median pain scores were reduced from 6 to 0, while median VASUQOL increased from 10 to 16.5. WIFi scores were reduced in three out of eight of participants (37.5%).Conclusion: Wound Express appears to be safe and may decrease pain, improve wound healing and improve quality of life for chronic limb-threatening ischemia patients. Adequately powered, prospectively randomized trials of the Wound Express system to assess its efficacy and safety are warranted.

Exploring the Effects of Human Bone Marrow-Derived Mononuclear Cells on Angiogenesis In Vitro.

Cell therapies involving the administration of bone marrow-derived mononuclear cells (BM-MNCs) for patients with chronic limb-threatening ischemia (CLTI) have shown promise; however, their overall effectiveness lacks evidence, and the exact mechanism of action remains unclear. In this study, we examined the angiogenic effects of well-controlled human bone marrow cell isolates on endothelial cells. The responses of endothelial cell proliferation, migration, tube formation, and aortic ring sprouting were analyzed in vitro, considering both the direct and paracrine effects of BM cell isolates. Furthermore, we conducted these investigations under both normoxic and hypoxic conditions to simulate the ischemic environment. Interestingly, no significant effect on the angiogenic response of human umbilical vein endothelial cells (HUVECs) following treatment with BM-MNCs was observed. This study fails to provide significant evidence for angiogenic effects from human bone marrow cell isolates on human endothelial cells. These in vitro experiments suggest that the potential benefits of BM-MNC therapy for CLTI patients may not involve endothelial cell angiogenesis.

Effect of Limb Salvage by Excimer Laser Angioplasty Plus Low-Pressure Balloon Inflation in Chronic Limb-Threatening Ischemia Patients with Infrapopliteal Vessel Disease.

Patients with chronic limb-threatening ischemia (CLTI) often exhibit long, diffuse, totally occluded and heavily calcified infrapopliteal (IP) lesions. This study evaluated limb salvage after peripheral excimer laser atherectomy (PELA) plus low-pressure balloon inflation (LPBI) without stent deployment in CLTI patients with severe IP disease. We retrospectively evaluated 70 consecutive patients with 109 IP vessels who underwent PELA plus LPBI from 2010 to 2013. Technical success was defined as at least one IP straight-line flow being achieved below the malleolus. Binary logistic regression was performed to identify factors associated with 6-month limb salvage. Of the 109 IP vessels, 100 (91.7%) were totally occluded, and none of the patients received a stent. Of the 70 patients, 20% were octogenarians, and 85.8% had a Rutherford-Becker class 5 and 6. The technical success rate was 87.1% and 6-month limb salvage rate was 78.6%. Rutherford score was negatively correlated with clinical success (adjusted odds ratio 0.24; p = 0.028). No immediate major cardiovascular events were recorded during admission. PELA plus LPBI may be a treatment option for complex IP lesions in patients with CLTI. Higher Rutherford class was correlated with a lower 6-month limb salvage rate. However, a large-scale study with a control group is needed to clarify our results.

The effects of high quality team medicine on outcomes of chronic limb-threatening ischemia patients with infrapopliteal bypass.

A team approach for treatment of patients with CLTI is used worldwide. However, the quality of team medicine is a concern. The Global Vascular Guidelines provide recommendations for high quality team medicine, but there is limited knowledge of the significance of team quality in CLTI treatment. The objective of this study is to evaluate the effects of team quality on clinical outcomes after infrapopliteal bypass. A retrospective analysis was performed in 337 patients who underwent 414 infrapopliteal bypasses under a team medicine approach at a single center between 2009 and 2021. In 2017, team medicine was reorganized for improvement of quality. Comparisons were made between before (Group 1; 160 patients, 195 limbs) and after (Group 2; 177 patients, 219 limbs) reorganization. The primary endpoints were limb salvage and wound healing after infrapopliteal bypass. The patients included 227 males (67%) and had a median age of 76 [68-83]years. Diabetes mellitus was present in 67% and end-stage renal disease with hemodialysis in 37%. The follow-up rate was 96% in a mean follow-up period of 31±30months. The 3-year limb salvage rate was significantly lower in Group 1 (before reorganization) than in Group 2 (after reorganization) (84% vs 95%, p = .001). The wound healing rates in the whole cohort were 72% at 6months and 85% at 12months, with no significant differences between the groups. In multivariate analysis, the risk factors for major amputation were treatment before reorganization (HR 2.68; p = .017), hemodialysis (HR 2.27; p = .017), and non-ambulatory status (HR 2.63; p = .005). A reorganized team approach with the goal of higher quality was independently associated with reduced major amputation for patients with CLTI treated with infrapopliteal bypass. This result indicates the importance of a high quality team approach for success of this treatment.

Five Year Survival in Medicare Patients Undergoing Interventions for Peripheral Arterial Disease: a Retrospective Cohort Analysis of Linked Registry Claims Data

To justify upfront risks of offering elective interventions for intermittent claudication (IC), patients should have reasonable life expectancy to derive durable clinical benefits. Open surgery for chronic limb threatening ischaemia (CLTI) is maximally beneficial in patients surviving ≥ 2 years. Our goal was to assess long term survival after IC and CLTI interventions. In a retrospective cohort analysis, the Vascular Quality Initiative (VQI) registry from 1 January 2010 to 31 May 2021 was queried for peripheral vascular intervention (PVI), infra-inguinal bypasses (IIB), and supra-inguinal bypasses (SIB) for IC and CLTI across 286 US centres. VQI linkage to Medicare insurance claims provided 5 year survival data. Multivariable analysis identified factors associated with 5 year mortality. There were 31 457 PVIs (44.7% IC, 55.3% CLTI), 7 978 IIBs (26.9% IC, 73.1% CLTI), and 2 149 SIBs (50.1% IC, 49.9% CLTI) recorded in the VQI. Among PVI, IIB, and SIB cohorts, average ages were 75, 73, and 72 years, respectively. Respective 5 year mortality after PVI for IC and CLTI was 37.2% and 71.1%; after IIB for IC and CLTI it was 37.8% and 60%; and after SIB for IC and CLTI it was 33.8% and 53.8%. On multivariable analysis, across all procedures, end-stage renal disease, CLTI, congestive heart failure, anaemia, chronic obstructive pulmonary disease, and prior amputation were independently associated with increased mortality. Pre-admission home living and pre-operative aspirin use were independently associated with decreased mortality. Long term survival in Medicare patients undergoing interventions in VQI centres for peripheral arterial disease is poor. Two thirds of CLTI patients and over one third of IC patients were not alive at 5 years. Intervening for IC in patients with high mortality risk should be avoided. For CLTI patients identified with decreased survival likelihood, intervention durability may be less important than invasiveness. Pre-operative medical optimisation should always be undertaken.