Critical limb ischemia: introduction

Trans-pedal access for endovascular revascularization in complex infra-popliteal lesions in critically ischemic limb: A cohort study

Background

critical limb ischemia is one of the most challenging cases we face nowadays with high risk for amputation, retrograde trans-pedal angioplasty offers an alternative technique after failure of traditional ante-grade angioplasty.

Patients and Methods

96 patients underwent trans-pedal or trans-tibial retrograde angioplasty after failure of the traditional ante-grade angioplasty with the aid of US, 21-gauge needle and 0.018 wire through sheath-less approach as a last chance for revascularization.

Results

clinical success or improvement in 77 cases (80.2%), and in other 19 cases (19.8%) there was no clinical success or improvement. The technical success was achieved in 81 cases with percentage of (84.4%), and not achieved in 15 cases (15.6%) only.

Conclusions

Retrograde Trans-pedal angioplasty is an efficient, safe, and practical procedure with a high technical success and a relatively minimal procedural adverse effect.

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retrograde trans-pedal angioplasty offers an alternative technique after failure of traditional ante-grade angioplasty.

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Retrograde Trans-pedal angioplasty is an efficient, safe, and practical procedure

Major Lower Limb Amputations and Amputees in an Aging Population in Southwest Finland 2007-2017

Purpose

The aim of the present study was to describe and analyze changes in the incidences of lower extremity amputations (LEAs), patient characteristics, vascular history of amputees and survival in Southwest Finland.

Patients and Methods

This is a retrospective patient study in the Hospital District of Southwest Finland. All consecutive patients with atherosclerosis and diabetes-caused LEA, between 1st January 2007 and 31st December 2017, were included. The annual incidences of major LEA patients were statistically standardized. Patients' diagnoses, functional status, previous revascularizations and minor amputations were recorded, and survival was analyzed.

Results

During the 11-year-period major LEAs were performed on 891 patients, 118 (13.2%) were urgent operations. The overall incidence of major LEA was 17.2/100 000 and was age-dependent (3.1 for ≤64 years, 34.3 for 65-74 years, 81.5 for 75-84 years, 216 for ≥85 years). A decrease in incidence was detected in the <65 year-age-group (incidence 4.98 in 2007 and 1.88 in 2017; p = 0.0018). Among older age groups, there was no significant change. Half (50.6%) of all amputees were diabetics. Altogether, 472 patients (53.0%) had a history of revascularization before LEA. 80.1% of index amputations were transfemoral and 19.9% transtibial. Re-surgery was performed on 94 (10.5%) patients. The 1-, 3- and 5-year overall survival were 56%, 30%, and 18%, respectively.

Conclusion

Our results suggest that in an aging population, despite good availability of vascular services, a significant number of patients are not fit for active revascularization, and LEA is the only feasible treatment for critical limb ischemia.

ROS-responsive nanoparticle-mediated delivery of CYP2J2 gene for therapeutic angiogenesis in severe hindlimb ischemia

With critical limb ischemia (CLI) being a multi-factorial disease, it is becoming evident that gene therapy with a multiple bio-functional growth factor could achieve better therapeutic outcomes. Cytochrome P450 epoxygenase-2J2 (CYP2J2) and its catalytic products epoxyeicosatrienoic acids (EETs) exhibit pleiotropic biological activities, including pro-angiogenic, anti-inflammatory and cardiovascular protective effects, which are considerably beneficial for reversing ischemia and restoring local blood flow in CLI. Here, we designed a nanoparticle-based pcDNA3.1-CYP2J2 plasmid DNA (pDNA) delivery system (nanoparticle/pDNA complex) composed of a novel three-arm star block copolymer (3S-PLGA-po-PEG), which was achieved by conjugating three-armed PLGA to PEG via the peroxalate ester bond. Considering the multiple bio-functions of CYP2J2-EETs and the sensitivity of the peroxalate ester bond to H₂O₂, this nanoparticle-based gene delivery system is expected to exhibit excellent pro-angiogenic effects while improving the high oxidative stress and inflammatory micro-environment in ischemic hindlimb. Our study reports the first application of CYP2J2 in the field of therapeutic angiogenesis for CLI treatment and our findings demonstrated good biocompatibility, stability and sustained release properties of the CYP2J2 nano-delivery system. In addition, this nanoparticle-based gene delivery system showed high transfection efficiency and efficient VEGF expression in vitro and in vivo. Intramuscular injection of nanoparticle/pDNA complexes into mice with hindlimb ischemia resulted in significant rapid blood flow recovery and improved muscle repair compared to mice treated with naked pDNA. In summary, 3S-PLGA-po-PEG/CYP2J2-pDNA complexes have tremendous potential and provide a practical strategy for the treatment of limb ischemia. Moreover, 3S-PLGA-po-PEG nanoparticles might be useful as a potential non-viral carrier for other gene delivery applications.

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Cytochrome P450 epoxygenase-2J2 (CYP2J2) was first applied in the field of therapeutic angiogenesis for critical limb ischemia treatment.

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The ROS-responsive three-arm star block copolymer (3S-PLGA-po-PEG) was synthesized with peroxalate ester as H₂O₂-responsive linkages through the esterification reaction of oxalyl chloride and hydroxyl group.

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The CYP2J2 nano-delivery system achieved high transfection efficiency and significant therapeutic angiogenesis effect.

Fibrosis Distinguishes Critical Limb Ischemia Patients from Claudicants in a Transcriptomic and Histologic Analysis

Most patients with critical limb ischemia (CLI) from peripheral arterial disease (PAD) do not have antecedent intermittent claudication (IC). We hypothesized that transcriptomic analysis would identify CLI-specific pathways, particularly in regards to fibrosis. Derivation cohort data from muscle biopsies in PAD and non-PAD (controls) was obtained from the Gene Expression Omnibus (GSE120642). Transcriptomic analysis indicated CLI patients (N = 16) had a unique gene expression profile, when compared with non-PAD controls (N = 15) and IC (N = 20). Ninety-eight genes differed between controls and IC, 2489 genes differed between CLI and controls, and 2783 genes differed between CLI and IC patients. Pathway enrichment analysis showed that pathways associated with TGFβ, collagen deposition, and VEGF signaling were enriched in CLI but not IC. Receiver operating curve (ROC) analysis of nine fibrosis core gene expression revealed the areas under the ROC (AUC) were all >0.75 for CLI. Furthermore, the fibrosis area (AUC = 0.81) and % fibrosis (AUC = 0.87) in validation cohort validated the fibrosis discrimination CLI from IC and control (all n = 12). In conclusion, transcriptomic analysis identified fibrosis pathways, including those involving TGFβ, as a novel gene expression feature for CLI but not IC. Fibrosis is an important characteristic of CLI, which we confirmed histologically, and may be a target for novel therapies in PAD.

Anticoagulation in addition to dual antiplatelet therapy has no impact on long-term follow-up after endovascular treatment of (sub)acute lower limb ischemia

Background: To assess the impact of short- vs. long-term anticoagulation in addition to standard dual antiplatelet therapy (DAPT) upon endovascular treatment of (sub)acute thrombembolic occlusions of the lower extremity. Patient and methods: Retrospective analysis was conducted on 202 patients with a thrombembolic occlusion of lower extremities, followed by crirical limb ischemia that received endovascular treatment including thrombolysis, mechanical thrombectomy, or a combination of both between 2006 and 2015 at a single center. Following antithrombotic regimes were compared: 1) dual antiplatelet therapy, DAPT for 4 weeks (aspirin 100 mg/d and clopidogrel 75 mg/d) upon intervention, followed by a lifelong single antiplatelet therapy; 2) DAPT plus short term anticoagulation for 4 weeks, followed by a lifelong single antiplatelet therapy; 3) DAPT plus long term anticoagulation for > 4 weeks, followed by a lifelong anticoagulation. Results: Endovascular treatment was associated with high immediate revascularization (> 98 %), as well as overall and amputation-free survival rates (> 85 %), independent from the chosen anticoagulation regime in a two-year follow up, p > 0.05. Anticoagulation in addition to standard antiplatelet therapy had no significant effect on patency or freedom from target lesion revascularization (TLR) 24 months upon index procedure for both thrombotic and embolic occlusions. Severe bleeding complications occurred more often in the long-term anticoagulation group (9.3 % vs. 5.6 % (short-term group) and 6.5 % (DAPT group), p > 0.05). Conclusions: Our observational study demonstrates that the choice of an antithrombotic regime had no impact on the long-term follow-up after endovascular treatment of acute thrombembolic limb ischemia whereas prolonged anticoagulation was associated with a nominal increase in severe bleeding complications.

Gene-based therapies in patients with critical limb ischemia

Critical limb ischemia (CLI) constitutes a life-limiting and life-threatening disease. Revascularization, either endovascular or surgical, remains the best treatment option accompanied by medication and risk factor modification. Patients unable to undergo revascularization, referred as 'no-option patients', have been the center of interest the last few years, subjected to treatment therapies based on proteins (mainly growth factors) involved in angiogenesis via gene delivery to the ischemic tissue. Areas covered: This review focuses on these growth factors, gives an update of the studies available, discusses the possible problems that influence outcomes and describes future perspectives including possible new technologies that will improve them. Additionally, the authors attempt to place therapeutic angiogenesis to the bigger frame of tailored therapy in CLI. Expert opinion: Although encouraging in the beginning, growth factor therapy results have been equivocal and inconclusive. And while it would be misleading to approach gene therapy as panacea, its effect on the micro-circulatory level activating angiogenesis and arteriogenesis could act as an important adjunct in personalized treatment.

Burden of Readmissions Among Patients With Critical Limb Ischemia

BACKGROUND

Readmissions constitute a major health care burden among critical limb ischemia (CLI) patients.

OBJECTIVES

This study aimed to determine the incidence of readmission and factors affecting readmission in CLI patients.

METHODS

All adult hospitalizations with a diagnosis code for CLI were included from State Inpatient Databases from Florida (2009 to 2013), New York (2010 to 2013), and California (2009 to 2011). Data were merged with the directory available from the American Hospital Association to obtain detailed information on hospital-related characteristics. Geographic and routing analysis was performed to evaluate the effect of travel time to the hospital on readmission rate.

RESULTS

Overall, 695,782 admissions from 212,241 patients were analyzed. Of these, 284,189 were admissions with a principal diagnosis of CLI (primary CLI admissions). All-cause readmission rates at 30 days and 6 months were 27.1% and 56.6%, respectively. The majority of these were unplanned readmissions. Unplanned readmission rates at 30 days and 6 months were 23.6% and 47.7%, respectively. The major predictors of 6-month unplanned readmissions included age, female sex, black/Hispanic race, prior amputation, Charlson comorbidity index, and need for home health care or rehabilitation facility upon discharge. Patients covered by private insurance were least likely to have a readmission compared with Medicaid/no insurance and Medicare populations. Travel time to the hospital was inversely associated with 6-month unplanned readmission rates. There was a significant interaction between travel time and major amputation as well as travel time and revascularization strategy; however, the inverse association between travel time and unplanned readmission rate was evident in all subgroups. Furthermore, length of stay during index hospitalization was directly associated with the likelihood of 6-month unplanned readmission (odds ratio for log-transformed length of stay: 2.39 [99% confidence interval: 2.31 to 2.47]).

CONCLUSIONS

Readmission among patients with CLI is high, the majority of them being unplanned readmissions. Several demographic, clinical, and socioeconomic factors play important roles in predicting readmissions.

Vascular surgery institutional-based quality and performance measures for the care of patients with critical limb ischemia

The intensity and quality of medical care provided to patients with critical limb ischemia (CLI) varies by geography, ethnicity, and socioeconomic status. Although vascular surgery societal performance goals have been set forth, no consensus criteria exist by which to benchmark the quality of health care delivery specifically for CLI patients. We review existing broad performance measures for patients with peripheral vascular disease and suggest those with optimal care delivery suited for CLI (eg, ankle-brachial index, optimal medical therapy, smoking cessation, and duplex surveillance). Further, we propose that diabetic management, degree of wound healing, and quality of life measures be considered as additional quality measures for CLI management. In combination, these criteria provide a simple yet powerful metric that might allow for standardization of CLI care and comparisons across institutions, with the potential for diminishing the disparity that exists in current treatment practices.