Endovascular therapies for peripheral arterial disease: an evidence-based review

A Combined "Vasculoplastic" Approach to the Vasculopathic Patient Undergoing Limb Salvage: Understanding the Role of Endovascular Revascularization for Lower Extremity Free Tissue Transfer

BACKGROUND

 Multidisciplinary care with vascular surgery and plastic surgery is essential for lower extremity free flap (LEFF) success in the chronic wound population with diabetes and peripheral vascular disease. There is a lack of understanding on performing targeted direct endovascular reperfusion on a vessel that will be used as the flap recipient. Our study compares outcomes of patients who received targeted revascularization (TR) to the recipient vessel for LEFF anastomosis versus nontargeted revascularization (NR) of arterial recipients prior to LEFF.

METHODS

 LEFF patients who underwent preoperative endovascular revascularization (ER) from July 2011 to January 2023 were reviewed. Location of ER, demographics, perioperative details, and outcomes were collected. TR was performed on the same vessel as the flap recipient and NR was located on a different vessel than the flap recipient.

RESULTS

 A total of 55 LEFF patients were identified. Overall, 50.91% (n = 28) received TR and 49.1% (n = 27) received NR. Average age was 60.3 ± 10.9 years and average Charlson Comorbidity Index was 5.3 ± 1.9. On preoperative angiogram, the TR group had significantly lower rates of ER above the knee (3.6 vs. 33.3%, p < 0.001). Immediate flap success rate was 98.2%, with no differences between groups (p = 1.000). No significant differences were found in rates of any postoperative flap complications (p = 0.898), takeback (p = 0.352), partial flap necrosis (p = 0.648), or dehiscence (p = 0.729). Both TR and NR groups had similar rates of a postoperative angiogram (42.9 vs. 48.2%, p = 0.694) and reintervention (35.7 vs. 40.7% p = 0.701). Amputation rates were similar between TR and NR (17.9 vs. 14.8%, p = 1.000).

CONCLUSION

 Close follow-up with vascular and plastic surgery is required for patients who undergo ER prior to LEFF, as nearly half of our cohort required additional endovascular procedures. Overall, we observed no significant differences in complication rates for the TR and NR groups, informing revascularization strategies for free tissue transfer in a highly comorbid chronic wound population.

Establishing a Classification System for Predicting Flow-Limiting Dissection After Balloon Angioplasty Using Explainable Machine-Learning Models: A Multicenter Retrospective Cohort Study

Objective:

Percutaneous transluminal angioplasty (PTA) is the primary method for treatment in peripheral arterial disease. However, some patients experience flow-limiting dissection (FLD) after PTA. We utilized machine learning and SHapley Additive exPlanations to identify and optimize a classification system to predict FLD after PTA.

Methods:

This was a multi-center, retrospective, cohort study. The cohort comprised 407 patients who underwent treatment of the femoropopliteal (FP) arteries in 3 institutions between January 2021 and June 2023. Preoperative computed tomography angiography images were evaluated to identify FP artery grading, chronic total occlusion (CTO), and vessel calcification (peripheral artery calcium scoring system [PACSS]). After PTA, FLD was identified by angiography. We trained and validated 6 machine-learning models to estimate FLD occurrence after PTA, and the best model was selected. Then, the sum of the Shapley values for each of CTO, FP, and PACSS was calculated for each patient to produce the CTO-FP-PACSS value. The CTO-FP-PACSS classification system was used to classify the patients into classes 1 to 4. Univariate and multivariate analyses were performed to validate the effectiveness of the CTO-FP-PACSS classification system for predicting FLD.

Results:

Overall, 407 patients were analyzed, comprising 189 patients with FLD and 218 patients without FLD. Differences in sex (71% males vs 54% males, p<0.001), CTO (72% vs 43%, p<0.001), FP (3.26±0.94 vs 2.66±1.06, p<0.001), and PACSS (2.39±1.40 vs 1.74±1.35, p<0.001) were observed between patients with and without FLD, respectively. The random forest model demonstrated the best performance (validation set area under the curve: 0.82). SHapley Additive exPlanations revealed CTO, PACSS, and FP as the 3 most influential FLD predictors, and the univariate and multivariate analyses confirmed CTO-FP-PACSS classification as an independent FLD predictor (multivariate hazard ratio 4.13; p<0.001).

Conclusion:

The CTO-FP-PACSS classification system accurately predicted FLD after PTA. This user-friendly system may guide surgical decision-making, helping choose between PTA and additional devices to reduce FLD in FP artery treatment.

Clinical impact

We utilised machine-learning techniques in conjunction with SHapley Additive exPlanations to develop a clinical classification system that predicts the probability of flow-limiting dissection (FLD) after plain old balloon angioplasty. This classification system categorises lesions into Classes 1–4 based on three factors: chronic total occlusion, femoropopliteal grading, and peripheral artery calcium scoring. Each class demonstrated a different probability of developing FLD. This classification system may be valuable for surgeons in their clinical practice, as well as serving as a source of inspiration for other researchers.

Alleviating iatrogenic effects of paclitaxel via antiinflammatory treatment

BACKGROUND

Paclitaxel (PTX) is touted as an essential medicine due to its extensive use as a chemotherapeutic agent for various cancers and an antiproliferative agent for endovascular applications. Emerging studies in cardio-oncology implicate various vascular complications of chemotherapeutic agents.

METHODS

We evaluated the inflammatory response induced by the systemic administration of PTX. The investigation included RNAseq analysis of primary human endothelial cells (ECs) treated with PTX to identify transcriptional changes in pro-inflammatory mediators. Additionally, we used dexamethasone (DEX), a well-known antiinflammatory compound, to assess its effectiveness in counteracting these PTX-induced changes. Further, we studied the effects of PTX on monocyte chemoattractant protein-1 (MCP-1) levels in the media of ECs. The study also extended to in vivo analysis, where a group of mice was injected with PTX and subsequently harvested at different times to assess the immediate and delayed effects of PTX on inflammatory mediators in blood and aortic ECs.

RESULTS

Our RNAseq analysis revealed that PTX treatment led to significant transcriptional perturbations in pro-inflammatory mediators such as MCP-1 and CD137 within primary human ECs. These changes were effectively abrogated when DEX was administered. In vitro experiments showed a marked increase in MCP-1 levels in EC media following PTX treatment, which returned to baseline upon treatment with DEX. In vivo, we observed a threefold increase in MCP-1 levels in blood and aortic ECs 12 h post-PTX administration. Similar trends were noted for CD137 and other downstream mediators like tissue factor, vascular cell adhesion molecule 1, and E-selectin in aortic ECs.

CONCLUSION

Our findings illustrate that PTX exposure induces an upregulation of atherothrombotic mediators, which can be alleviated with concurrent administration of DEX. Considering these observations, further long-term investigations should focus on understanding the systemic implications associated with PTX-based therapies and explore the clinical relevance of DEX in mitigating such risks.

Covered Stents vs Bare Metal Stents for Aortoiliac Arterial Diseases: A Systematic Review and Meta-Analysis

PURPOSE

Covered stents and bare metal stents (BMS) have been regarded as viable treatment options for aortoiliac arterial diseases. We performed this systematic review and meta-analysis to compare the efficacy of covered stents with BMS for aortoiliac arterial diseases.

MATERIALS AND METHODS

The Cochrane Library, Embase, and Medline databases were searched by 2 authors (C.Z. and Z.W.) to retrieve all studies comparing the outcomes of covered stents vs BMS for aortoiliac arterial diseases. The Cochrane tool and the Newcastle-Ottawa scale were used to assess the risk of bias in randomized controlled trials and observational studies, respectively. The outcomes at the same stage reported in at least 2 studies were pooled together. The fixed effects model combined the data when I2<50%, otherwise the random effects model was applied. The results for dichotomous variables were presented as odds ratio (OR) or risk difference and 95% confidence interval (CI); continuous variables were reported as mean difference and 95% CI.

RESULTS

Herein, 10 studies with a total of 1695 limbs were included. The covered stents significantly increased the freedom from target lesion revascularization (OR 2.85, 95% CI: 1.28-6.33, p=0.010) compared to the BMS during a 24-month follow-up. However, no statistically significant difference was found in the technical success, primary patency, secondary patency, major adverse events (MAEs), ankle-brachial index (ABI) improvement, limb salvage, and survival between the two groups.

CONCLUSION

Compared to BMS, covered stents appear to have similar technical success, primary patency, secondary patency, MAEs, ABI improvement, limb salvage, and survival but may have advantages in reducing target lesion revascularization. More well-designed, prospective studies are warranted to determine such findings.

CLINICAL IMPACT

Covered stents may increase freedom from target lesion revascularization (TLR) compared to bare metal stents (BMS) in the treatment of aortoiliac arterial diseases. However, technical success, primary patency, secondary patency, major adverse events (MAEs), ABI improvement, limb salvage, and survival were similar. The aforementioned results are still not sufficient to draw a solid conclusion about the selection of stents for aortoiliac arterial diseases. More well-designed, prospective studies are warranted to determine such findings.

Association between sex and long-term outcomes of endovascular treatment for peripheral artery disease

BACKGROUND

Endovascular peripheral vascular intervention (PVI) has become the primary revascularization technique used for peripheral artery disease (PAD). Yet, there is limited understanding of long-term outcomes of PVI among women versus men. In this study, our objective was to investigate sex differences in the long-term outcomes of patients undergoing PVI.

METHODS

We performed a cohort study of patients undergoing PVI for PAD from January 1, 2010 to September 30, 2015 using data in the Vascular Quality Initiative (VQI) registry. Patients were linked to fee-for-service Medicare claims to identify late outcomes including major amputation, reintervention, major adverse limb event (major amputation or reintervention [MALE]), and mortality. Sex differences in outcomes were evaluated using cumulative incidence curves, Gray's test, and mixed effects Cox proportional hazards regression accounting for patient and lesion characteristics using inverse probability weighted estimates.

RESULTS

In this cohort of 15,437 patients, 44% (n = 6731) were women. Women were less likely to present with claudication than men (45% vs. 49%, p < 0.001, absolute standardized difference, d = 0.08) or be able to ambulate independently (ambulatory: 70% vs. 76%, p < 0.001, d = 0.14). There were no major sex differences in lesion characteristics, except for an increased frequency of tibial artery treatment in men (23% vs. 18% in women, p < 0.001, d = 0.12). Among patients with claudication, women had a higher risk-adjusted rate of major amputation (hazard ratio [HR] = 1.72, 95% confidence interval [CI]: 1.18-2.49), but a lower risk of mortality (HR = 0.86, 95% CI: 0.75-0.99). There were no sex differences in reintervention or MALE for patients with claudication. However, among patients with chronic limb-threatening ischemia, women had a lower risk-adjusted hazard of major amputation (HR = 0.79, 95% CI: 0.67-0.93), MALE (HR = 0.86, 95% CI: 0.78-0.96), and mortality (HR = 0.86, 95% CI: 0.79-0.94).

CONCLUSION

There is significant heterogeneity in PVI outcomes among men and women, especially after stratifying by symptom severity. A lower overall mortality in women with claudication was accompanied by a higher risk of major amputation. Men with chronic limb-threatening ischemia had a higher risk of major amputation, MALE, and mortality. Developing sex-specific approaches to PVI that prioritizes limb outcomes in women can improve the quality of vascular care for men and women.

Predictors of Amputation-free Survival after Endovascular Intervention for Chronic Limb-Threatening Ischemia in the Modern era

BACKGROUND

Chronic limb-threatening (CLTI) is associated with 25% limb loss and 25% mortality at 1-year. Its lethality increases to 45% in patients subjected to a major amputation. Percutaneous peripheral intervention (PPI) constitutes an attractive and less morbid treatment option for patients with CLTI. The purpose of this study was to assess amputation-free survival (AFS) in a contemporary cohort treated with endovascular recanalization and assess its predictors.

METHODS

Patients with CLTI undergoing endovascular revascularization at a single regional hospital between 2015-2019 were reviewed. Baseline demographic characteristics, Wound, Ischemia, and foot Infection (WIfI) stage, technical details, and clinical outcomes were tabulated. The primary endpoint was AFS; a P-value < 0.05 was used for univariate screening and inclusion in a multivariable model.

RESULTS

A total of 137 limbs in 111 patients were studied. Comorbidities were prevalent and included diabetes (65%), congestive heart failure (21%), and dialysis dependence (18%). The majority of revascularized limbs presented with advanced wounds (66% WIfI stages 3-4; 47% Rutherford category 6). Presenting WIfI stages were similar across races (P = 0.26). Peripheral interventions most commonly targeted femoropopliteal disease (69%), although 26% were multilevel. Percutaneous atherectomy, stenting, and paclitaxel-coated or eluting devices were utilized in 68%, 28%, and 15% of cases, respectively. After a median follow-up of 16 months (interquartile range IQR = 4-29 months), significant independent predictors of reduced AFS included nonWhite race (HR = 2.96 [1.42-6.17]; P = 0.004) and WIfI stage 4 wounds (HR = 2.23 [1.10-4.52]; P = 0.026). At one year following successful revascularization, only 59% ± 1% of patients were alive with their limb intact.

CONCLUSIONS

Despite considerable and consistent advances in urban health care delivery and the techniques of PPI, CLTI remains a morbid and deadly disease. Even in the endovascular era, nearly half of all patients presenting with CLTI will lose their limb and/or life within the first year. Unfortunately, late-stage presentation continues to be commonplace. Although endovascular intervention can reliably restore patency to affected arteries, this appears insufficient to restore most patients to health.

Changes in national endovascular management of femoropopliteal artery disease: an analysis of the 2011-2019 Medicare data

PURPOSE

Current evidence supports endovascular approaches (including balloon angioplasty, atherectomy, and stenting) for management of femoropopliteal peripheral artery disease (PAD); this study sought to describe national trends in utilization of each intervention.

METHODS

The Medicare Physician/Supplier Procedure Summary dataset containing 100% of part B claims were interrogated for years 2011-2019. Current procedural terminology codes specific for femoropopliteal angioplasty, stenting, and atherectomy were used to create summary statistics for utilization by year, place of service (hospital inpatient, hospital outpatient, and office-based lab), and provider specialty (cardiology, radiology, and surgery).

RESULTS

Atherectomy use increased from 34,732 procedures (33%) in 2011 to 75,435 (53%) in 2019 and became the dominant treatment strategy for femoropopliteal PAD. Relative utilization of stenting (36,793/35% to 28,899/20%) and angioplasty only (34,398/32% to 38,228/27%) decreased concomitantly from 2011 to 2019. Atherectomy use by 2019 was two-fold higher in office-based labs compared with the outpatient hospital setting (44,767 and 20,901, respectively). Treatment strategy varied by provider specialty in 2011 when cardiologists used atherectomy most frequently (17,925/43%), while radiologists used angioplasty alone (5,928/6%) and surgeons stented (18,009/37%) most frequently. By 2019 all specialties utilized atherectomy most frequently (29,564/59% for cardiology, 10,912/58% for radiology, and 33,649/47% for surgery).

CONCLUSION

National approach to endovascular management of femoropopliteal PAD has changed since 2011, towards an implant-free strategy including a multi-fold increase in atherectomy use. Discordant rates of atherectomy between the ambulatory hospital and office-based settings highlight the need for comparative effectiveness studies to guide management.

Measurement of Revascularization in the Hind Limb After Experimental Ischemia in Mice

Peripheral vascular disease is a major cause of morbidity and mortality, and is a consequence of impaired blood flow to the limbs. This arises due to the inability of the tissue to develop sufficiently functional collateral vessel circulation to overcome occluded arteries, or microvascular impairment. The mouse hind limb model of hind limb ischemia can be used to investigate the impact of different treatment modalities, behavioral changes, or genetic knockout. Here we described the model in detail, providing examples of adverse events, and details of ex vivo analysis of blood vessel density.

Principal predictors of major adverse limb events in diabetic peripheral artery disease: A narrative review

Background and aims

The increasing prevalence of diabetes mellitus is causing a massive growth of peripheral artery disease incidences, a disabling complication of diabetic atherosclerosis, which leads often to the amputation of the affected limb. Critical limb ischemia is the terminal disease stage, which requires a prompt intervention to relieve pain and save limbs. However, patients undergoing revascularization often suffer from cardiovascular, cerebrovascular and major adverse limb events with poor outcomes. Furthermore, the same procedure performed in apparently similar patients has various outcomes and lack of an outcome predictive support causes a high lower limb arterial revascularization rate with disastrous effects for patients. We collected the main risk factors of major adverse limb events in a more readable and immediate format of the topic, to propose an overview of parameters to manage effectively peripheral artery disease patients and to propose basics of a new predictive tool to prevent from disabling vascular complications of the disease.

Methods

Most recent and updated literature about the prevalence of major adverse limb events in peripheral artery disease was reviewed to identify possible main predictors.

Results

In this article, we summarized major risk factors of limb revascularization failure and disabling vascular complications collecting those parameters principally responsible for major adverse limb events, which provides physio-pathological explanation of their role in peripheral artery disease.

Conclusion

We evaluated and listed a panel of possible predictors of MALE (Major Adverse Limb Event) in order to contribute to the development of a predictive score, based on a summary of the main risk factors reported in scientific articles, which could improve the management of peripheral artery disease by preventing vascular accidents.

The evolving role of endovascular therapy in the management of arterial thoracic outlet syndrome

OBJECTIVE

Over the past two decades, vascular surgeons have successfully incorporated endovascular techniques to the routine care of patients with arterial thoracic outlet syndrome (ATOS). However, no reports have documented the impact of endovascular therapy. This study describes the trends in management of ATOS by vascular surgeons and outcomes after both endovascular and open repair of the subclavian artery.

METHODS

We queried a single-institution, prospectively maintained thoracic outlet syndrome database for ATOS cases managed by vascular surgeons. For comparison, cases were divided into two equal time periods, January 1986 to August 2003 (P-1) vs September 2003 to March 2021 (P-2), and by treatment modality, open vs endovascular. Clinical presentation, outcomes, and the involvement of vascular surgeons in endovascular therapy were compared between groups.

RESULTS

Of 2200 thoracic outlet syndrome cases, 51 were ATOS (27 P-1, 24 P-2) and underwent 50 transaxillary decompressive operations. Forty-eight cases (92%) presented with ischemic symptoms. Thrombolysis was done in 15 (29%). During P-1, vascular surgeons performed none of the catheter-based interventions. During P-2, vascular surgeons performed 60% of the angiograms, 50% of thrombolysis, and 100% of stent grafting. Subclavian artery pathology included 16 aneurysms (31%), 15 stenoses (29%), and 19 occlusions (37%). Compared with open aneurysmal repair, endovascular stent graft repairs took less time (241 vs 330 minutes; P = .09), incurred lower estimated blood loss (103 vs 150 mL; P = .36), and had a shorter length of stay (2.4 vs 5.0 days; P = .10). Yet the endovascular group had decreased primary (63% vs 77%; P = .481), primary assisted (75% vs 85%; P = .590), and secondary patency rates (88% vs 92%; P = .719), at a mean follow-up time of 3.0 years for the endovascular group and 6.9 years for the open group (P = .324). These differences did not achieve statistical significance. Functionally, 84% of patients were able to resume work or school. A majority of patients (88%) had a good to excellent functional outcome based on their Derkash score. Somatic pain scores and QuickDASH (disabilities of the arm, shoulder, and hand) scores decreased postoperatively, 2.9 vs 0.8 (P = .015) and 42.6 vs 12.6 (P = .004), respectively.

CONCLUSIONS

This study describes the evolving role of endovascular management of ATOS over the past two decades and documents the expanded role of vascular surgeons in the endovascular management of ATOS at a single institution. Compared with open repair, stent graft repair of the subclavian artery may be associated with shorter operative times, less blood loss, but decreased patency, without changes in long-term functional outcomes.

Mechano-chemo-biological Computational Models for Arteries in Health, Disease and Healing: From Tissue Remodelling to Drug-eluting Devices

This review aims to highlight urgent priorities for the computational biomechanics community in the framework of mechano-chemo-biological models. Recent approaches, promising directions and open challenges on the computational modelling of arterial tissues in health and disease are introduced and investigated, together with in silico approaches for the analysis of drug-eluting stents that promote pharmacological-induced healing. The paper addresses a number of chemo-biological phenomena that are generally neglected in biomechanical engineering models but are most likely instrumental for the onset and the progression of arterial diseases. An interdisciplinary effort is thus encouraged for providing the tools for an effective in silico insight into medical problems. An integrated mechano-chemo-biological perspective is believed to be a fundamental missing piece for crossing the bridge between computational engineering and life sciences, and for bringing computational biomechanics into medical research and clinical practice.

The SELUTION SLR™ drug-eluting balloon system for the treatment of symptomatic femoropopliteal lesions

Endovascular treatment has become first line therapy for the treatment of femoropopliteal disease. Drug-coated devices play a key role in maintaining vessel patency. In the past antiproliferative coating of drug-coated balloons (DCBs) exclusively consisted of paclitaxel. Use of limus drugs was limited by a short residency time in the vessel wall. Besides the drug, the SELUTION SLR™ drug-eluting balloon system consists of a coating formulation of four excipients. The first excipient is a biodegradable polymer (poly(lactic-co-glycolic acid)) that is intermixed with the sirolimus to form micro-reservoirs and regulates drug release via matrix degradation. This review summarizes the existing pre-clinical and clinical literature on treatment of femoropopliteal artery lesions with the SELUTION SLR DCB.

Gene-expression profiles of abdominal perivascular adipose tissue distinguish aortic occlusive from stenotic atherosclerotic lesions and denote different pathogenetic pathways

Perivascular adipose tissue (PVAT) helps regulate arterial homeostasis and plays a role in the pathogenesis of large vessel diseases. In this study, we investigated whether the PVAT of aortic occlusive lesions shows specific gene-expression patterns related to pathophysiology. By a genome-wide approach, we investigated the PVAT transcriptome in patients with aortoiliac occlusive disease. We compared the adipose layer surrounding the distal aorta (atherosclerotic lesion) with the proximal aorta (plaque-free segment), both within and between patients with complete aortoiliac occlusion (Oc) and low-grade aortic stenosis (St). We found that PVAT of the distal versus proximal aorta within both Oc- and St-patients lacks specific, locally restricted gene-expression patterns. Conversely, singular gene-expression profiles distinguished the PVAT between Oc- and St-patients. Functional enrichment analysis revealed that these signatures were associated with pathways related to metabolism of cholesterol, vessel tone regulation, and remodeling, including TGF-β and SMAD signaling. We finally observed that gene-expression profiles in omental-visceral or subcutaneous fat differentiated between Oc- and St-patients, suggesting that the overall adipose component associates with a different atherosclerosis burden. Our work points out the role of PVAT and, likely, other adipose tissues play in the pathophysiological mechanisms underlying atherosclerotic disease, including the abdominal aortic occlusive forms.

Entering Cardiac Rehabilitation With Peripheral Artery Disease: A RETROSPECTIVE COMPARISON TO CORONARY ARTERY DISEASE

PURPOSE

Supervised exercise is recommended for patients with peripheral artery disease (PAD) and patients with coronary artery disease (CAD). Both conditions share common etiology as atherosclerotic diseases. The clinical profile, cardiorespiratory fitness, and exercise prescriptions of PAD, CAD, and patients with concomitant PAD and CAD (BOTH) have yet to be compared upon entry into cardiac rehabilitation (CR).

METHODS

Cardiopulmonary, demographic, and anthropometric assessments were conducted at entry to CR between January 2006 and December 2017.

RESULTS

Among 9701 consecutively enrolled patients, there were 94.6% with CAD (n = 9179), 1.5% with PAD (n = 143), and 3.9% with BOTH (n = 379). Only 5.4% (n = 522) of all patients entering CR had a diagnosis of PAD. Compared with CAD, patients with PAD and BOTH were older (mean ± SD = 62.5 ± 11.1 vs 67.9 ± 11.4 and 69.2 ± 9.8 yr, P < .01), had higher resting systolic blood pressure (124 ± 17 vs 130 ± 17 and 133 ± 18 mm Hg, P < .01), had lower cardiorespiratory fitness (19.7 ± 6.3 vs 15.6 ± 4.8 and 15 ± 4.5 mL/kg/min, P < .01), and were more likely to have diabetes (25% vs 35% and 41%, P < .01), abdominal obesity (39% vs 54% and 51%, P < .01), and initially prescribed lower-intensity exercise (84.4 ± 14.1 vs 74.1 ± 15.7 and 70.0 ± 14.6 m/min exercise pace, P < .01), reflecting the complex nature of patients diagnosed with PAD.

CONCLUSIONS

Patients referred with PAD have a cardiovascular risk profile that places them at a greater risk for a repeat or first cardiac event compared with patients with CAD. Referral to structured exercise and risk factor modification programs should be considered to aid in the management of PAD.

A New Preprocedural Score to Predict Bleeding Complications of Endovascular Interventions for Peripheral Artery Disease

Purpose: To investigate the bleeding complications associated with endovascular therapy (EVT) for peripheral artery disease (PAD) and develop a dedicated peripheral bleeding score (PBS). Materials and Methods: This prospective, single-center study enrolled 530 patients (mean age 67.6±9.8 years; 396 men) undergoing endovascular procedures between August 2016 and July 2018 for chronic PAD. Primary endpoints were the incidence of 30-day bleeding complications [minor and major (prolonging hospitalization, causing permanent sequelae, or resulting in death)], the identification of factors associated with bleeding events, and the development of a dedicated PBS based on univariate and multivariate analysis. Hazard ratios (HR) and 95% confidence intervals (CI) are reported. The HAS-BLED score was compared with the PBS. Results: The overall peripheral bleeding complication rate was 3.8% (20/530), of which 3.2% (17/530) were major and included 4 (0.7%) active retroperitoneal bleeding events and 13 (2.4%) pseudoaneurysms. The annualized incidences of overall bleeding and major bleeding complications were 1.9% and 1.6%, respectively. Multivariable regression analysis identified age ≥75 as a correlate of significantly increased bleeding risk (HR 3.32, 95% CI 1.12 to 9.80, p<0.02). Male gender (HR 0.193, 95% CI 0.49 to 0.75, p<0.001) and statin therapy (HR 0.245, 95% CI 0.08 to 0.71, p=0.01) were correlated with a significantly decreased bleeding risk. Based on the regression analysis findings an 8-point PBS was developed, demonstrating 75.0% sensitivity and 78.4% specificity in detecting bleeding complications. The HAS-BLED score failed to identify 30-day bleeding events. Conclusion: The annualized incidence of bleeding complications associated with peripheral EVT was low. Advanced age and female sex were correlated with increased bleeding risk. The PBS demonstrated satisfactory statistical performance and could be considered for inclusion in the preprocedural endovascular checklist to help optimize intra- and postprocedural care.

Inflammatory Cytokines Associated With Failure of Lower-Extremity Endovascular Revascularization (LER): A Prospective Study of a Population With Diabetes

OBJECTIVE

Peripheral artery disease (PAD) is one of the most relevant complications of diabetes. Although several pharmacological and revascularization approaches are available for treating patients with diabetes and PAD, an endovascular approach is often associated with postprocedural complications that can increase the risk for acute limb ischemia or amputation. However, no definitive molecular associations have been described that could explain the difference in outcomes after endovascular treatment in patients with diabetes, PAD, and chronic limb-threatening ischemia (CLTI).

RESEARCH DESIGN AND METHODS

We evaluated the relationship between the levels of the main cytokines associated with diabetic atherosclerosis and the outcomes after endovascular procedures in patients with diabetes, PAD, and CLTI.

RESULTS

A total of 299 patients with below-the-knee occlusive disease who were undergoing an angioplasty procedure were enrolled. The levels of key cytokines-osteoprotegerin (OPG), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and C-reactive protein (CRP)-were measured, and major adverse limb events (MALE) and major adverse cardiovascular events (MACE) were assessed 1, 3, 6, and 12 months after the procedure. There was a linear trend from the lowest to the highest quartile for each cytokine at baseline and incident MALE. A linear association was also observed between increasing levels of each cytokine and incident MACE. Receiver operating characteristics models were constructed using clinical and laboratory risk factors, and the inclusion of cytokines significantly improved the prediction of incident events.

CONCLUSIONS

We demonstrated that elevated OPG, TNF-α, IL-6, and CRP levels at baseline correlate with worse vascular outcomes in patients with diabetes, PAD, and CLTI undergoing an endovascular procedure.

The Ever-Humbling Challenge of Peripheral Artery Disease Treatment Seen Across the Sexes

See Article Ramkumar et al

Role of Sex in Determining Treatment Type for Patients Undergoing Endovascular Lower Extremity Revascularization

Background Limited data exist to describe factors that influence the use of different endovascular treatments for peripheral arterial disease. Therefore, we studied sex differences in the utilization of endovascular treatment modalities and their impact on arterial patency. Methods and Results We analyzed procedures from 2010 to 2016 in the Vascular Quality Initiative for arteries treated with percutaneous transluminal angioplasty (PTA) alone, stenting (with/without PTA), and atherectomy (with/without PTA). We explored sex differences in treatment modality by arterial segment (iliac, femoropopliteal, and tibial) with multivariable logistic regression. We used Kaplan-Meier survival analysis and multivariable Cox regression to study sex differences in arterial reintervention and occlusion. In this cohort, patients (n=58 247, mean age 68 years, 41% women,) had 106 073 arteries treated (median=2 arteries, interquartile range=1-3). Half (50%) of these arteries were treated with stents, 39% with PTA alone, and 11% with atherectomy. After risk adjustment, women were less likely to undergo stenting or atherectomy (versus PTA alone) in the femoropopliteal (stent risk ratio=0.78 [0.74-0.82]; atherectomy risk ratio=0.69 [0.58-0.82]) and tibial arteries (stent risk ratio=0.70 [0.55-0.89]; atherectomy risk ratio=0.87 [0.70-1.07]). In the iliac arteries there was no sex difference in stenting, and atherectomy was rarely used (0.2%). Women underwent reintervention in the femoropopliteal arteries (hazard ratio=1.28 [1.17-1.40]) or developed an occlusion in the iliac (hazard ratio=1.42 [1.12-1.81]) and femoropopliteal arteries (hazard ratio=1.19 [1.06-1.34]) more frequently than men. Conclusions Women were less likely to undergo stenting or atherectomy and had higher rates of occlusion and reintervention, especially in the femoropopliteal arteries. Evidence-based guidelines are needed to guide optimal use of endovascular treatments for men and women.

Novel balloon technologies to minimize dissection of peripheral angioplasty

INTRODUCTION

Percutaneous transluminal angioplasty (PTA) currently remains the endovascular treatment of choice in a large percentage of patients suffering from peripheral artery disease (PAD). However, the mechanism of angioplasty itself can cause some extent of arterial dissection leading to early vessel restenosis/reocclusion. Current endovascular imaging studies have reported a higher rate of arterial dissection than previously reported in literature and advocated the correlation of dissection with poor patency. Thus, there is the need of developing devices to minimize dissection and bailout stenting.

AREAS COVERED

The present review focuses on newly-developed balloon angioplasty technologies designed to minimize arterial wall distress and consequently the rate of dissections. Available literature regarding three new specialty balloons is being reviewed, highlighting their value and limitations. Authors' future perspective about the benefits of utilizing specialty balloons towards a metal free and dissection free future is also provided.

EXPERT OPINION

By understanding the mechanism of angioplasty and thus developing devices which cause minimal or no arterial wall distress, the rate of dissections and bailout stenting can be minimized and long-term clinical outcomes of endovascular therapy can be optimized.

Endovascular Repair of an Iliac Artery Pseudoaneurysm Using a Surgeon-Reconstructed Prosthetic Graft and a Bare Metal Stent

Iliac artery aneurysms are usually asymptomatic. Herein, we report a novel strategy for the repair of a pseudoaneurysm involving the external iliac artery using a conventional artificial graft and bare metal stent. A 76-year-old male patient presented with severe resting pain and right foot discoloration. Computed tomography angiography revealed a right distal external iliac artery pseudoaneurysm, with severe calcified occlusion at the right common and superficial femoral arteries. After exposing the right femoral artery, long-segment endarterectomy and patch angioplasty with the ipsilateral greater saphenous vein were performed. Before the completion of patch angioplasty, a surgeon-modified 8-mm expanded polytetrafluoroethylene (ePTFE) graft was inserted for complete pseudoaneurysm repair. If a commercial covered stent is not available, minimally invasive endovascular repair can be safely performed using a surgeon-modified ePTFE graft and bare metal stent.

Lower Extremity Amputation and Health Care Utilization in the Last Year of Life among Medicare Beneficiaries with ESRD

BACKGROUND

Lower extremity amputation is common among patients with ESRD, and often portends a poor prognosis. However, little is known about end-of-life care among patients with ESRD who undergo amputation.

METHODS

We conducted a mortality follow-back study of Medicare beneficiaries with ESRD who died in 2002 through 2014 to analyze patterns of lower extremity amputation in the last year of life compared with a parallel cohort of beneficiaries without ESRD. We also examined the relationship between amputation and end-of-life care among the patients with ESRD.

RESULTS

Overall, 8% of 754,777 beneficiaries with ESRD underwent at least one lower extremity amputation in their last year of life compared with 1% of 958,412 beneficiaries without ESRD. Adjusted analyses of patients with ESRD showed that those who had undergone lower extremity amputation were substantially more likely than those who had not to have been admitted to-and to have had prolonged stays in-acute and subacute care settings during their final year of life. Amputation was also associated with a greater likelihood of dying in the hospital, dialysis discontinuation before death, and less time receiving hospice services.

CONCLUSIONS

Nearly one in ten patients with ESRD undergoes lower extremity amputation in their last year of life. These patients have prolonged stays in acute and subacute health care settings and appear to have limited access to hospice services. These findings likely signal unmet palliative care needs among seriously ill patients with ESRD who undergo amputation as well as opportunities to improve their care.

In vivo comparison of key quantitative parameters measured with 3D peripheral angiography, 2D peripheral quantitative angiography and intravascular ultrasound

The aim of this study was to compare the measures of luminal stenosis between the two-dimensional (2D) and three-dimensional (3D) Quantitative Vessel Analysis (QVA) generated by CAAS QVA software and intravascular ultrasound (IVUS). Invasive contrast angiography is considered gold standard for diagnostic imaging and intervention in both coronary and peripheral arterial disease. However, it is based on 2D images depicting complicated 3D arterial anatomy. To overcome these limitations, 3D QVA has been developed to bridge the gap between 2D QVA and endovascular imaging. Thirty porcine femoral angiograms (common, profunda and superficial) with matching intravascular ultrasound (IVUS) pullbacks featuring variable degree of stenosis were analysed by 2D QVA, 3D QVA and quantitative IVUS. All 3 modalities provided similar data regarding the length of the investigated segment. Median lumen diameter was nearly identical in IVUS (4.69 mm) and in 3D QVA (4.76 mm) but quite a bit lower in 2D QVA (4.47 mm, Kruskal-Wallis test p = 0.1648). Lumen area measured in 2D QVA was lower than in IVUS and in 3D QVA. Lumen areas rendered by IVUS and 3D QVA were similar. Bland-Altman plots showed that the lowest differences were observed between IVUS and 3D QVA. IVUS and 3D QVA results were consistently higher than 2D QVA. 3D QVA is a useful surrogate of IVUS for precise luminal morphology measurements of peripheral arteries, rendering results that are much closer to IVUS than 2D QVA can provide.

The Advantage of Common Femoral Endarterectomy Alone or Combined with Endovascular Treatment

Purpose

Although common femoral artery endarterectomy (CFAE) is regarded as the standard treatment modality for common femoral artery (CFA) disease, availability of advanced endovascular techniques has resulted in an increased number of CFA disease being treated. We evaluated clinical outcomes in a contemporary series of patients who were treated for CFA disease using endarterectomy alone or combined with endovascular treatment.

Materials and Methods

We retrospectively reviewed 46 patients from November 2001 through December 2007. The treated lesions were divided into 4 groups based on operative procedure: group I (n=11), CFAE alone; group II (n=15), CFAE and iliac artery (IA) endovascular treatment; group III (n=6), CFAE and superficial femoral artery (SFA) endovascular treatment; group IV (n=14), CFAE and IA and SFA endovascular treatment or bypass surgery.

Results

The degree of CFA steno-occlusion was not different among the groups. The 3-year primary patency rates of each group were 88.9±10.5%, 60.0±14.5%, 62.5±21.3%, and 83.9±10.4%, respectively. The 3-year primary assisted patency rates were 100%, 70.0±13.0%, 62.5±21.3%, and 89.3±10.4%, while 3-year secondary patency rates were 100%, 80.0±13.0%, 62.5±21.3%, and 92.3±7.4%, respectively. There was no procedure-related mortality. Significant improvement of ankle-brachial index was achieved in all groups.

Conclusion

CFAE alone is the treatment of choice for excellent patency and clinical improvement in steno-occlusive lesions confined to the CFA. In multiple steno-occlusive diseases, this procedure could be combined with endovascular procedures to reduce the operative risk in conditions with high morbidity.

Nanoparticles for Detection and Treatment of Peripheral Arterial Disease

Peripheral arterial disease (PAD) is defined as a slow, progressive disorder of the lower extremity arterial vessels characterized by chronic narrowing that often results in occlusion and is associated with loss of functional capacity. Although the PAD occurrence rate is increasing in the elderly population, outcomes with current treatment strategies are suboptimal. Hence, there is an urgent need to develop new technologies that overcome limitations of traditional modalities for PAD detection and therapy. In this Review, the application of nanotechnology as a tool that bridges the gap in PAD diagnosis and therapy is in focus. Several materials including synthetic, natural, biodegradable, and biocompatible materials are used to develop nanoparticles for PAD diagnostic and/or therapeutic applications. Moreover, various recent research approaches are being explored to diagnose PAD through multimodality imaging with different nanoplatforms. Further efforts include targeted delivery of various therapeutic agents using nanostructures as carriers to treat PAD. Last, but not least, despite being a fairly new field, researchers are exploring the use of nanotheranostics for PAD detection and therapy.

Recurrence of Critical Limb Ischemia After Endovascular Intervention in Patients with Diabetic Foot Ulcers

Objective: To establish the rate of clinical recurrence of critical limb ischemia (CLI) in diabetic patients with ischemic foot ulcers (DFUs) treated by percutaneous transluminal angioplasty (PTA). Approach: The study group was composed of 304 patients with ischemic DFUs treated by PTA. We evaluated the rate of clinical recurrence of CLI requiring a second PTA (repeated PTA [rePTA]), the factors related to CLI relapse, and the outcomes of rePTA patients. The follow-up was 12.5 ± 6.6 months. Results: Seventy-four of 304 patients (24.3%) needed rePTA. The mean time to rePTA was 3.5 ± 0.64 months. rePTA group in comparison with no rePTA group had lower rate of healing (28.5% vs. 71.9% p = 0.0001), higher rate of ulcer recurrence (20% vs. 10.3% p = 0.03), major amputation (24.3% vs. 4.3% p = 0.0005), and death (33.3% vs. 7.9% p = 0.002). Glycated hemoglobin, type A1C (HbA1c; 2.2 [1.9-2.7] p = 0.02) and dialysis (1.5 [1.4-3.6] p = 0.006) were independently associated to clinical recurrence of CLI after PTA. Innovation: To identify the outcomes of patients with clinical recurrence of CLI and the clinical factors involved to reduce the rate of restenosis after endovascular treatment and improve the rate of limb salvage. Conclusions: Clinical recurrence of CLI is associated with a high rate of nonhealing ulcer recurrence, major amputation, and death. Dialysis and impaired glycemic control were independent predictors of CLI relapse after endovascular treatment.

Performance Assessment of a Radiofrequency Powered Guidewire for Crossing Peripheral Arterial Occlusions Based on Lesion Morphology

Endovascular wires and devices for peripheral arterial disease therapy have evolved greatly, yet failure rates of these procedures remain high. Information on lesion composition may inform device selection to improve the success rates of these procedures. This paper, presents an approach for informed guidewire selection. The objective of this study is to quantitatively assess the performance of a radiofrequency powered guidewire in the crossing of various morphology types of peripheral chronic total occlusions. Samples taken from amputated patient limbs are characterized by magnetic resonance imaging. Using a customized catheter test station, the performance of a radiofrequency powered guidewire in puncturing these lesions is compared to a conventional guidewire, and to itself when not powered. The analysis includes quantitative and statistical comparisons of the puncture forces experienced by the different guidewires in "hard" vs. "soft" lesions as well as qualitative assessment of deflections, buckling and puncture success of the wires. Results indicate that the use of radiofrequency ablation significantly reduces the required puncture force, reduced events of buckling and deflection, and resulted in a significantly higher puncture success rate.

Proliferation of human aortic endothelial cells on Nitinol thin films with varying hole sizes

In this paper, we present the effect of micron size holes on proliferation and growth of human aortic endothelial cells (HAECs). Square shaped micron size holes (5, 10, 15, 20 and 25 μm) separated by 10 μm wide struts are fabricated on 5 μm thick sputter deposited Nitinol films. HAECs are seeded onto these micropatterned films and analyzed after 30 days with fluorescence microscopy. Captured images are used to quantify the nucleus packing density, size, and aspect ratio. The films with holes ranging from 10 to 20 μm produce the highest cell packing densities with cell nucleus contained within the hole. This produces a geometrically regular grid like cellular distribution pattern. The cell nucleus aspect ratio on the 10-20 μm holes is more circular in shape when compared to aspect ratio on the continuous film or larger size holes. Finally, the 25 μm size holes prevented the formation of a continuous cell monolayer, suggesting the critical length that cells cannot bridge is between 20 to 25 μm.

Lower extremity computed tomography angiography can help predict technical success of endovascular revascularization in the superficial femoral and popliteal artery

OBJECTIVE

Preprocedural computed tomography angiography (CTA) assists in evaluating vascular morphology and disease distribution and in treatment planning for patients with lower extremity peripheral artery disease (PAD). The aim of the study was to determine the predictive value of radiographic findings on CTA and technical success of endovascular revascularization of occlusions in the superficial femoral artery-popliteal (SFA-pop) region.

METHODS

Medical records and available imaging studies were reviewed for patients undergoing endovascular intervention for PAD between January 2013 and December 2015 at a single academic institution. Radiologists reviewed preoperative CTA scans of patients with occlusions in the SFA-pop region. Radiographic criteria previously used to evaluate chronic occlusions in the coronary arteries were used. Technical success, defined as restoration of inline flow through the SFA-pop region with <30% stenosis at the end of the procedure, and intraoperative details were evaluated.

RESULTS

From 2013 to 2015, there were 407 patients who underwent 540 endovascular procedures for PAD. Preprocedural CTA scans were performed in 217 patients (53.3%), and 84 occlusions in the SFA-pop region were diagnosed. Ten occlusions were excluded as no endovascular attempt to cross the lesion was made because of extensive disease or concomitant iliac intervention. Of the remaining 74 occlusions in the SFA-pop region, 59 were successfully treated (80%) and 15 were unsuccessfully crossed (20%). The indications for revascularization were claudication in 57% of patients and critical limb ischemia in the remaining patients. TransAtlantic Inter-Society Consensus A, B, and C occlusions were treated with 87% success, whereas D occlusions were treated with 68% success (P = .047). There were nine occlusions with 100% vessel calcification that was associated with technical failure (P = .014). Longer lengths of occlusion were also associated with technical failure (P = .042). Multiple occlusions (P = .55), negative remodeling (P = .69), vessel runoff (P = .56), and percentage of vessel calcification (P = .059) were not associated with failure. On multivariable analysis, 100% calcification remained the only significant predictor of technical failure (odds ratio, 9.0; 95% confidence interval, 1.8-45.8; P = .008).

CONCLUSIONS

Analysis of preoperative CTA shows 100% calcification as the best predictor of technical failure of endovascular revascularization of occlusions in the SFA-pop region. Further studies are needed to determine the cost-effectiveness of obtaining preoperative CTA for lower extremity PAD.

Peripheral Stent Thrombosis Leading to Acute Limb Ischemia and Major Amputation: Incidence and Risk Factors in the Aortoiliac and Femoropopliteal Arteries

PURPOSE

To report the real-world incidence and risk factors of stent thrombosis in the aortoiliac and femoropopliteal arteries in case of bare nitinol stent (BNS) or covered nitinol stent (CNS) placement from a single-centre retrospective audit.

MATERIALS AND METHODS

Medical records of consecutive patients treated with peripheral stent placement for claudication or critical limb ischemia were audited for definite stent thrombosis defined as imaging confirmed stent thrombosis that presented as acute limb-threatening ischemia. Cases were stratified between aortoiliac and femoropopliteal anatomy. Cox regression analysis was employed to adjust for baseline clinical and procedural confounders and identify predictors of stent thrombosis and major limb loss.

RESULTS

256 patients (n = 277 limbs) were analysed over a 5-year period (2009-2014) including 117 aortoiliac stents (34 CNS; 12.8 ± 5.0 cm and 83 BNS; 7.8 ± 4.0 cm) and 160 femoropopliteal ones (60 CNS; 21.1 ± 11.0 cm and 100 BNS; 17.5 ± 11.9 cm). Median follow-up was 1 year. Overall stent thrombosis rate was 6.1% (17/277) after a median of 43 days (range 2-192 days) and affected almost exclusively the femoropopliteal segment (12/60 in the CNS cohort vs. 4/100 in the BNS; p = 0.001). Annualized stent thrombosis rates (per 100 person-years) were 12.5% in case of CNS and 1.4% in case of BNS (HR 6.3, 95% CI 2.4-17.9; p = 0.0002). Corresponding major amputations rates were 8.7 and 2.5%, respectively (HR 4.5, 95% CI 2.7-27.9; p = 0.0006). On multivariable analysis, critical leg ischemia and CNS placement were the only predictors of stent thrombosis. Diabetes, critical leg ischemia, femoropopliteal anatomy, long stents and CNS were independent predictors of major amputations.

CONCLUSIONS

Placement of long femoropopliteal covered nitinol stents is associated with an increased incidence of acute stent thrombosis and ensuing major amputation. Risks are significantly lower in the aortoiliac vessels and with use of bare nitinol stents.

Effect of Chronic Kidney Disease on Mortality in Patients Who Underwent Lower Extremity Peripheral Vascular Intervention

It is known that chronic kidney disease (CKD) is associated with increased postoperative morbidity and mortality in patients with peripheral artery disease who underwent lower extremity surgical revascularization; however, outcomes after peripheral vascular intervention (PVI) are less well established. This study sought to determine the impact of CKD on adverse outcomes in patients with peripheral artery disease who underwent PVI. Using data from the Veteran Affairs Clinical Assessment, Reporting, and Tracking System Program, we identified a cohort of 755 patients who underwent lower extremity PVI from June 2005 to August 2010 at 33 sites. The outcomes of interest were mortality, progression to dialysis, myocardial infarction, limb amputation, and stroke. Kaplan-Meier survival analysis and Cox proportional hazard frailty models assessed the association between CKD and adverse outcomes. Of the patients who underwent lower extremity PVI, 201 patients (27%) had CKD. The presence of CKD was associated with decreased survival (5-year survival probability of CKD compared with non-CKD: 49.9% [41.6% to 59.9%] vs 80.1% [76.2% to 84.1]), which persisted after risk adjustment (HR 1.57; 95% confidence interval 1.13 to 2.19). In addition, there was a significant association between CKD and progression to dialysis (HR 6.62; 95% confidence interval 2.25 to 19.43). In contrast, there was no association between CKD and re-hospitalization for myocardial infarction, limb amputation, or stroke. In conclusion, CKD is present in 1 of 4 patients who underwent PVI and is associated with increased risk of mortality and progression to dialysis.

Bivalirudin versus unfractionated heparin during peripheral vascular interventions: A Propensity-matched Study

OBJECTIVES

This study aimed to compare the association of access site complications and the use of unfractionated heparin versus bivalirudin during subinguinal peripheral vascular intervention.

BACKGROUND

Compared to unfractionated heparin, bivalirudin has been associated with fewer bleeding complications in patients undergoing percutaneous coronary intervention but more ischemic events. The safety and efficacy of direct thrombin inhibitors in peripheral vascular interventions is not well defined.

METHODS

We compared the incidence of in-hospital access site complications and discharge status among patients in the multicenter, prospective Vascular Quality Initiative registry who underwent peripheral vascular intervention between August 2007 and January 2014 using bivalirudin or unfractionated heparin. Propensity score matching was used to obtain a balanced cohort of 1,524 patients in each treatment group.

RESULTS

Patients treated with bivalirudin had a significantly lower incidence of access site hematomas (2.4% vs. 3.9%, P = 0.018), shorter post-procedural hospitalization (1.0 vs. 1.2 days, P < 0.001) and lower rates of discharge to a nursing home or rehabilitation center rather than home (7.61% vs. 9.73%, P = 0.034) when compared with unfractionated heparin-treated patients. The incidence of in-hospital access site occlusion, distal embolization, and mortality did not differ significantly between groups.

CONCLUSIONS

Patients who received bivalirudin had lower rates of access site hematoma, shorter length of stay, and improved discharge status compared with unfractionated heparin during hospitalization for peripheral vascular intervention. Randomized comparisons of these agents are needed to confirm these findings. © 2016 Wiley Periodicals, Inc.

Interventional treatment of the left subclavian in 2 patients with coronary steal syndrome

In patients with history of coronary artery disease angina pectoris is usually attributed to the progression of atherosclerotic lesions. However, in patients with previous coronary artery bypass graft operation (CABG) using internal mammary artery grafts, great vessel disease should also be considered. Herein we present two patients with history of CABG whose symptoms were suspicious for coronary ischemia. During cardiac catheterization reverse blood flow was observed from the left artery disease to the left internal mammary artery (LIMA) graft in both cases. After angioplasty and stent implantation of the left subclavian artery antegrade flow was restored in the LIMA grafts and both patients had complete resolution of symptoms.

Antithrombotic Therapy After Peripheral Vascular Intervention

Cardioprotective medications and risk-factor modification are the hallmarks of treatment for all patients with peripheral artery disease (PAD). If symptoms are life-limiting and/or do not respond to conservative treatment, endovascular or surgical revascularization can be considered especially for patients with critical limb ischemia or acute limb ischemia. The rates of peripheral vascular intervention (PVI) have risen dramatically over the past few decades and much of this care have shifted from inpatient hospital settings to outpatient settings and office-based clinics. While PVI rates have surged and technology advancements have dramatically changed the face of PVI, the data behind optimal antithrombotic therapy following PVI is scant. Currently in the USA, most patients are treated with indefinite aspirin therapy and a variable duration of clopidogrel (or other P2Y12 inhibitor)-typically 1 month, 3 months, or indefinite therapy. More observational analyses and randomized clinical trials evaluating clinically relevant outcomes such as cardiovascular morbidity/mortality and the risk of bleeding are needed to guide the optimal role and duration of antithrombotic therapy post-PVI.

Anesthetic considerations for endovascular abdominal aortic aneurysm repair

Aneurysm is defined as a localized and permanent dilatation with an increase in normal diameter by more than 50%. It is more common in males and can affect up to 8% of elderly men. Smoking is the greatest risk factor for abdominal aortic aneurysm (AAA) and other risk factors include hypertension, hyperlipidemia, family history of aneurysms, inflammatory vasculitis, and trauma. Endovascular Aneurysm Repair [EVAR] is a common procedure performed for AAA, because of its minimal invasiveness as compared with open surgical repair. Patients undergoing EVAR have a greater incidence of major co-morbidities and should undergo comprehensive preoperative assessment and optimization within the multidisciplinary settings. In majority of cases, EVAR is extremely well-tolerated. The aim of this article is to outline the Anesthetic considerations related to EVAR.

Endovascular Therapy for Large Vessel Vasculopathy in HIV-infected Patients

OBJECTIVES

To evaluate outcomes after endovascular treatment of patients with aneurysmal or occlusive vasculopathy in HIV-infected patients.

METHODS

Retrospective analysis of a prospective database of treatment outcomes in patients with HIV related vasculopathies between April 2005 and September 2015.

RESULTS

Sixty HIV patients presented with post-traumatic pseudoaneurysm formation (n = 7), aneurysmal disease (n = 24) or occlusive disease (n = 29 (48%)). The majority were male (42/60 (70%)), with a mean age of 43.9 years (SD ± 12.6). All seven patients with a post-traumatic pseudoaneurysm were treated by insertion of a covered stent (n = 6) or coiling (n = 1). All were successfully treated at 30 days, but only one patient returned for late surveillance. 23/24 patients who underwent insertion of a stent graft/covered stent for aneurysmal disease returned for 30 day review (one asymptomatic stent graft occlusion). Only 11 patients attended for late surveillance; 9/11 were asymptomatic with patent stent grafts. Late stent occlusion occurred in two (no further action (n = 1), major limb amputation (n = 1). In the 29 patients who underwent endovascular treatment for occlusive disease, 9 (31%) had immediate treatment failure (including 8 amputations (28%)). Of the sixteen who returned for serial review, 8 (50%) suffered further complications including 4 amputations. Overall, 12/29 treated patients (41%) ultimately underwent amputation.

CONCLUSIONS

In the immediate short term, an 'endovascular first' strategy was associated with good outcomes in HIV patients with aneurysmal disease. By contrast, outcomes were poor in HIV patients with occlusive disease. Whether this relates to the underlying natural history of HIV occlusive vasculopathies remains unclear. One major problem in trying to formulate meaningful management strategies is a generalised reluctance for HIV patients to return for surveillance.

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.

Comparison of the non-invasive Nexfin® monitor with conventional methods for the measurement of arterial blood pressure in moderate risk orthopaedic surgery patients

Objective

Continuous invasive arterial blood pressure (IBP) monitoring remains the gold standard for BP measurement, but traditional oscillometric non-invasive intermittent pressure (NIBP) measurement is used in most low-to-moderate risk procedures. This study compared non-invasive continuous arterial BP measurement using a Nexfin® monitor with NIBP and IBP monitors.

Methods

This was a single-centre, prospective, pilot study in patients scheduled for elective orthopaedic surgery. Systolic BP, diastolic BP and mean arterial blood pressure (MAP) were measured by Nexfin®, IBP and NIBP at five intraoperative time-points. Pearson correlation coefficients, Bland–Altman plots and trending ability of Nexfin® measurements were used as criteria for success in the investigation of measurement reliability.

Results

A total of 20 patients were enrolled in the study. For MAP, there was a sufficient correlation between IBP/Nexfin® (Pearson = 0.75), which was better than the correlation between IBP/NIBP (Pearson = 0.70). Bland–Altman analysis of the data showed that compared with IBP, there was a higher percentage error for MAP_NIBP (30%) compared with MAP_Nexfin® (27%). Nexfin® and NIBP underestimated systolic BP; NIBP also underestimated diastolic BP and MAP. Trending ability for MAP_Nexfin® and MAP_NIBP were comparable to IBP.

Conclusion

Non-invasive BP measurement with Nexfin® was comparable with IBP and tended to be more precise than NIBP.

Covered vs Uncovered Stents for Aortoiliac and Femoropopliteal Arterial Disease

Purpose: To evaluate outcomes of covered vs bare metal stents for the treatment of lower limb peripheral artery disease. Methods: A search of electronic databases was performed to identify all studies comparing outcomes of covered vs bare metal stents for treatment of aortoiliac and femoropopliteal arterial disease. The Cochrane tool and the Newcastle-Ottawa scale were used to assess the risk of bias in randomized controlled trials (RCTs) and observational studies, respectively. Fixed or random effects models were applied to analyze pooled outcome data. The results for dichotomous outcome variables are presented as the odds ratio (OR) and 95% confidence interval (CI); intergroup comparisons of continuous clinical variables are reported as the mean difference (MD) and 95% CI. Results: Two RCTs and 4 retrospective cohort studies, enrolling 744 patients (mean age 67 years; 477 men) and 918 diseased arteries, were identified. For aortoiliac disease, treatment with a covered stent showed no significant improvement in primary patency (OR 2.10, 95% CI 0.48 to 9.11, p=0.32), but it was associated with higher ankle-brachial index (ABI) (MD 0.08, 95% CI 0.07 to 0.09, p<0.001) and a lower reintervention rate (OR 0.19, 95% CI 0.09 to 0.42, p<0.001). For femoropopliteal disease, use of covered stents was associated with increased primary patency (OR 1.84, 95% CI 1.11 to 3.06, p=0.02), higher ABI (MD 0.08, 95% CI 0.00 to 0.16, p=0.04), and a lower reintervention rate (OR 0.51, 95% CI 0.30 to 0.87, p=0.01). No significant differences in technical success, complications, limb salvage, or survival were identified between the groups in either segment. Conclusion: Theoretically, the use of covered stents may increase the patency rate due to decreased restenosis after stent placement. This analysis found that the primary patency was improved with the use of a covered stent in femoropopliteal lesions but not in aortoiliac disease. Improved outcomes were seen with covered stents compared with bare metal stents as indicated by a lower need for reintervention and an improved ABI. It remains to be investigated whether such beneficial effects can be translated into improved clinical outcomes, such as limb salvage and amputation-free survival. Long-term results of the comparative efficacy of covered stents over bare metal stents are not currently available.

Association between health status and long-term mortality after percutaneous revascularization of peripheral artery disease

OBJECTIVES

To explore the association of health status change and long-term survival among patients with symptomatic peripheral artery disease (PAD).

BACKGROUND

Early gains in health status after successful endovascular therapy (EVT) for symptomatic PAD can be maintained up to 1 year. Whether such health status improvements are associated with long-term survival benefits is unknown.

METHODS

Between February 2001 and August 2004, 258 patients with symptomatic PAD treated with EVT participated in a prospective study evaluating baseline and 1 year health status using the Peripheral Artery Questionnaire (range 0-100, higher scores = better). All-cause mortality was assessed for all patients at a median of 9.4 years following EVT.

RESULTS

The mean age at enrollment was 68 ± 11 years; 61% were male, 97% were Caucasian, and 38% had diabetes. Patients with a clinically meaningful health status improvement (≥8 points) 1 year after their index procedure (79%) were identified as responders. Responders had a significantly better 10 year survival compared with nonresponders (60% vs 38%, p = 0.025). Responder status was associated with a survival advantage that persisted in risk-adjusted analysis (adjusted hazard ratio for long-term mortality, 0.66 [95% CI, 0.45-0.97]; p = 0.036).

CONCLUSIONS

Among patients with symptomatic PAD undergoing EVT, improvement of PAD-specific health status at 1 year follow-up was associated with improved long-term survival. Whether additional treatment for patients with poor response to EVT could improve long-term survival warrants further investigation. © 2016 Wiley Periodicals, Inc.

The role of clinical evidence in emergent therapies: an empirical study on femoropopliteal stent-angioplasty in Europe

RATIONALE, AIMS AND OBJECTIVE

A delayed availability of clinical evidence in rapidly emerging therapies is considered a major problem. In this study, we examined whether evidence from clinical studies has influenced the therapy of a major disease in industrial countries, peripheral arterial disease (PAD), using novel femoropopliteal stent-angioplasty.

METHOD

This analysis of retrospective time series data uses multivariate linear regression to investigate associations between published clinical evidence on femoropopliteal stent-angioplasty from Q3/2004 to Q4/2010 and the demand for femoropopliteal stents in Germany, France, Italy and the UK between Q1/2005 and Q4/2010, controlling for the prevalence of PAD risk factors, cardiovascular drug demand, reimbursement of health care providers for stent implantation, stent selling prices of manufacturers and economic indicators.

RESULTS

We did not observe any association of published clinical evidence with femoropopliteal stent demand in Germany, France, Italy and the UK, while we observed such associations for varying control variables at different time lags respectively.

CONCLUSION

We observed no association between published clinical evidence of femoropopliteal stent-angioplasty and its use in any of the four countries. The country-specific context and practice-related variables at a centre and individual doctor level may have limited the role of published clinical evidence in emerging femoropopliteal stent-angioplasty. More research is needed at this context, centre and individual level.