Mitochondrial transfer mediates endothelial cell engraftment through mitophagy.

Ischaemic diseases such as critical limb ischaemia and myocardial infarction affect millions of people worldwide1. Transplanting endothelial cells (ECs) is a promising therapy in vascular medicine, but engrafting ECs typically necessitates co-transplanting perivascular supporting cells such as mesenchymal stromal cells (MSCs), which makes clinical implementation complicated2,3. The mechanisms that enable MSCs to facilitate EC engraftment remain elusive. Here we show that, under cellular stress, MSCs transfer mitochondria to ECs through tunnelling nanotubes, and that blocking this transfer impairs EC engraftment. We devised a strategy to artificially transplant mitochondria, transiently enhancing EC bioenergetics and enabling them to form functional vessels in ischaemic tissues without the support of MSCs. Notably, exogenous mitochondria did not integrate into the endogenous EC mitochondrial pool, but triggered mitophagy after internalization. Transplanted mitochondria co-localized with autophagosomes, and ablation of the PINK1-Parkin pathway negated the enhanced engraftment ability of ECs. Our findings reveal a mechanism that underlies the effects of mitochondrial transfer between mesenchymal and endothelial cells, and offer potential for a new approach for vascular cell therapy.

Induced pluripotent stem cell-derived extracellular vesicles enriched with miR-126 induce proangiogenic properties and promote repair of ischemic tissue.

Emerging evidence suggests that stem cell-derived extracellular vesicles (EVs) may induce pro-regenerative effects in ischemic tissues by delivering bioactive molecules, including microRNAs. Recent studies have also shown pro-regenerative benefits of EVs derived from induced pluripotent stem (iPS) cells. However, the underlying mechanisms of EV benefits and the role of their transferred regulatory molecules remain incompletely understood. Accordingly, we investigated the effects of human iPS-derived EVs (iPS-EVs) enriched in proangiogenic miR-126 (iPS-miR-126-EVs) on functional properties of human endothelial cells (ECs) in vitro. We also examined the outcomes following EV injection in a murine model of limb ischemia in vivo. EVs were isolated from conditioned media from cultures of unmodified and genetically modified human iPS cells overexpressing miR-126. The iPS-miR-126-EVs were enriched in miR-126 when compared with control iPS-EVs and effectively transferred miR-126 along with other miRNAs to recipient ECs improving their functional properties essential for ischemic tissue repair, including proliferation, metabolic activity, cell survival, migration, and angiogenic potential. Injection of iPS-miR-126-EVs in vivo in a murine model of acute limb ischemia promoted angiogenesis, increased perfusion, and enhanced functional recovery. These observations corresponded with elevated expression of genes for several proangiogenic factors in ischemic tissues following iPS-miR-126-EV transplantation. These results indicate that innate pro-regenerative properties of iPS-EVs may be further enhanced by altering their molecular composition via controlled genetic modifications. Such iPS-EVs overexpressing selected microRNAs, including miR-126, may represent a novel acellular tool for therapy of ischemic tissues in vivo.

Influence of inframalleolar modifier P0/P1 on wound healing in bypass surgery vs endovascular therapy in patients with chronic limb-threatening ischemia.

OBJECTIVE: This study aimed to compare the influence of inframalleolar (IM) P0/P1 on wound healing in bypass surgery vs endovascular therapy (EVT) in patients with chronic limb-threatening ischemia (CLTI). METHODS: We retrospectively analyzed the multicenter data of patients who underwent infra-inguinal revascularization for CLTI between 2015 and 2022. IM P represents target artery crossing into foot, with intact pedal arch (P0) and absent or severely diseased pedal arch (P1). The endpoints were wound healing, limb salvage (LS), and postoperative complications. RESULTS: We analyzed 66 and 189 propensity score-matched pairs in the IM P0 and IM P1 cohorts, respectively. In the IM P0 cohort, the 1-year wound healing rates were 94.5% and 85.7% in the bypass surgery and EVT groups, respectively (P = .092), whereas those in the IM P1 cohort were 86.2% and 66.2% in the bypass surgery and EVT groups, respectively (P < .001). In the IM P0 cohort, the 2-year LS rates were 96.7% and 94.1% in the bypass surgery and EVT groups, respectively (P = .625), and those in the IM P1 cohort were 91.8% and 81.5% in the bypass surgery and EVT groups, respectively (P = .004). No significant differences were observed between the bypass surgery and EVT in terms of postoperative complication rates in either the IM P0 or P1 cohorts. CONCLUSIONS: Bypass surgery facilitated better wound healing and LS than EVT in patients with IM P1. Conversely, no differences in wound healing or LS were observed between groups in patients with IM P0. Bypass surgery should be considered a better revascularization strategy than EVT in patients with tissue loss and IM P1 disease.

Unraveling the differential mechanisms of revascularization promoted by MSCs & ECFCs from adipose tissue or umbilical cord in a murine model of critical limb-threatening ischemia.

BACKGROUND: Critical limb-threatening ischemia (CLTI) constitutes the most severe manifestation of peripheral artery disease, usually induced by atherosclerosis. CLTI patients suffer from high risk of amputation of the lower extremities and elevated mortality rates, while they have low options for surgical revascularization due to associated comorbidities. Alternatively, cell-based therapeutic strategies represent an effective and safe approach to promote revascularization. However, the variability seen in several factors such as cell combinations or doses applied, have limited their success in clinical trials, being necessary to reach a consensus regarding the optimal "cellular-cocktail" prior further application into the clinic. To achieve so, it is essential to understand the mechanisms by which these cells exert their regenerative properties. Herein, we have evaluated, for the first time, the regenerative and vasculogenic potential of a combination of endothelial colony forming cells (ECFCs) and mesenchymal stem cells (MSCs) isolated from adipose-tissue (AT), compared with ECFCs from umbilical cord blood (CB-ECFCs) and AT-MSCs, in a murine model of CLTI. METHODS: Balb-c nude mice (n:32) were distributed in four different groups (n:8/group): control shams, and ischemic mice (after femoral ligation) that received 50 µl of physiological serum alone or a cellular combination of AT-MSCs with either CB-ECFCs or AT-ECFCs. Follow-up of blood flow reperfusion and ischemic symptoms was carried out for 21 days, when mice were sacrificed to evaluate vascular density formation. Moreover, the long-term molecular changes in response to CLTI and both cell combinations were analyzed in a proteomic quantitative approach. RESULTS: AT-MSCs with either AT- or CB-ECFCs, promoted a significant recovery of blood flow in CLTI mice 21 days post-ischemia. Besides, they modulated the inflammatory and necrotic related processes, although the CB group presented the slowest ischemic progression along the assay. Moreover, many proteins involved in the repairing mechanisms promoted by cell treatments were identified. CONCLUSIONS: The combination of AT-MSCs with AT-ECFCs or with CB-ECFCs promoted similar revascularization in CLTI mice, by restoring blood flow levels, together with the modulation of the inflammatory and necrotic processes, and reduction of muscle damage. The protein changes identified are representative of the molecular mechanisms involved in ECFCs and MSCs-induced revascularization (immune response, vascular repair, muscle regeneration, etc.).

Luminal Delivery of Pectin-Modified Oxygen Microbubbles Mitigates Rodent Experimental Intestinal Ischemia.

INTRODUCTION: Ischemic gut injury is common in the intensive care unit, impairs gut barrier function, and contributes to multiorgan dysfunction. One novel intervention to mitigate ischemic gut injury is the direct luminal delivery of oxygen microbubbles (OMB). Formulations of OMB can be modified to control the rate of oxygen delivery. This project examined whether luminal delivery of pectin-modified OMB (OMBp5) can reduce ischemic gut injury in a rodent model. METHODS: The OMBp5 formulation was adapted to improve delivery of oxygen along the length of small intestine. Adult Sprague-Dawley rats (n = 24) were randomly allocated to three groups: sham-surgery (SS), intestinal ischemia (II), and intestinal ischemia plus luminal delivery of OMBp5 (II + O). Ischemia-reperfusion injury was induced by superior mesenteric artery occlusion for 45 min followed by reperfusion for 30 min. Outcome data included macroscopic score of mucosal injury, the histological score of gut injury, and plasma biomarkers of intestinal injury. RESULTS: Macroscopic, microscopic data, and intestinal injury biomarker results demonstrated minimal intestinal damage in the SS group and constant damage in the II group. II + O group had a significantly improved macroscopic score throughout the gut mucosa (P = 0.04) than the II. The mean histological score of gut injury for the II + O group was significantly improved on the II group (P ≤ 0.01) in the proximal intestine only, within 30 cm of delivery. No differences were observed in plasma biomarkers of intestinal injury following OMBp5 treatment. CONCLUSIONS: This proof-of-concept study has demonstrated that luminal OMBp5 decreases ischemic injury to the proximal small intestine. There is a need to improve oxygen delivery over the full length of the intestine. These findings support further studies with clinically relevant end points, such as systemic inflammation and vital organ dysfunction.

Percutaneous Management of Dialysis Access Steal Syndrome: Interventions and Outcomes from a Single Institution's 20-Year Experience.

PURPOSE: To determine safety and effectiveness of percutaneous interventions performed by interventional radiologists at a single institution over 2 decades in patients with dialysis access steal syndrome (DASS). MATERIALS AND METHODS: A retrospective review of fistulograms from 2001 to 2021 (N = 11,658) was performed. In total, 286 fistulograms in 212 patients with surgically created dialysis accesses met inclusion criterion of fistulography for suspected DASS. Chart review collected data regarding patient demographics, comorbidities, access characteristics, fistulography findings, intervention(s) performed, and outcomes. Procedures with and without DASS intervention were compared. Odds ratios (ORs), adjusted for age, sex, comorbidities, access characteristics, and multiple within-patient events, were calculated using logistic regression to determine associations between steal intervention status and outcome variables: (a) major adverse events, (b) access preservation, and (c) follow-up surgery. A percutaneously treatable cause of DASS was present in 128 cases (45%). Treatment of DASS lesions was performed in 118 cases. Fifteen embolizations were also performed in patients without DASS lesions. RESULTS: Technical success of DASS interventions, defined by the Society of Interventional Radiology (SIR) reporting standards, was 94%; 54% of interventions resulted in DASS symptom improvement at a median follow-up of 15 days. Patients with steal intervention had 60% lower odds of follow-up surgery (OR, 0.4; P = .007). There was no difference in major adverse events (P = .98) or access preservation (P = .13) between groups. CONCLUSIONS: In this retrospective cohort study, approximately half of DASS fistulograms revealed a percutaneously treatable cause of steal. Over half of DASS interventions resulted in symptomatic relief. Percutaneous intervention was associated with lower odds of follow-up surgery without compromising access preservation.

Gene therapy by virus-like self-spooling toroidal DNA condensates for revascularization of hindlimb ischemia.

Peripheral arterial diseases (PAD) have been reported to be the leading cause for limb amputations, and the current therapeutic strategies including antiplatelet medication or intervene surgery are reported to not clinically benefit the patients with high-grade PAD. To this respect, revascularization based on angiogenetic vascular endothelial growth factor (VEGF) gene therapy was attempted for the potential treatment of critical PAD. Aiming for transcellular delivery of VEGF-encoding plasmid DNA (pDNA), we proposed to elaborate intriguing virus-like DNA condensates, wherein the supercoiled rigid micrometer-scaled plasmid DNA (pDNA) could be regulated in an orderly fashion into well-defined nano-toroids by following a self-spooling process with the aid of cationic block copolymer poly(ethylene glycol)-polylysine at an extraordinary ionic strength (NaCl: 600 mM). Moreover, reversible disulfide crosslinking was proposed between the polylysine segments with the aim of stabilizing these intriguing toroidal condensates. Pertaining to the critical hindlimb ischemia, our proposed toroidal VEGF-encoding pDNA condensates demonstrated high levels of VEGF expression at the dosage sites, which consequently contributed to the neo-vasculature (the particularly abundant formation of micro-vessels in the injected hindlimb), preventing the hindlimb ischemia from causing necrosis at the extremities. Moreover, excellent safety profiles have been demonstrated by our proposed toroidal condensates, as opposed to the apparent immunogenicity of the naked pDNA. Hence, our proposed virus-like DNA condensates herald potentials as gene therapy platform in persistent expressions of the therapeutic proteins, and might consequently be highlighted in the management of a variety of intractable diseases.

Spermatozoon-propelled microcellular submarines combining innate magnetic hyperthermia with derived nanotherapies for thrombolysis and ischemia mitigation.

Thrombotic cardiovascular diseases are a prevalent factor contributing to both physical impairment and mortality. Thrombolysis and ischemic mitigation have emerged as leading contemporary therapeutic approaches for addressing the consequences of ischemic injury and reperfusion damage. Herein, an innovative cellular-cloaked spermatozoon-driven microcellular submarine (SPCS), comprised of multimodal motifs, was designed to integrate nano-assembly thrombolytics with an immunomodulatory ability derived from innate magnetic hyperthermia. Rheotaxis-based navigation was utilized to home to and cross the clot barrier, and finally accumulate in ischemic vascular organs, where the thrombolytic motif was "switched-on" by the action of thrombus magnetic red blood cell-driven magnetic hyperthermia. In a murine model, the SPCS system combining innate magnetic hyperthermia demonstrated the capacity to augment delivery efficacy, produce nanotherapeutic outcomes, exhibit potent thrombolytic activity, and ameliorate ischemic tissue damage. These findings underscore the multifaceted potential of our designed approach, offering both thrombolytic and ischemia-mitigating effects. Given its extended therapeutic effects and thrombus-targeting capability, this biocompatible SPCS system holds promise as an innovative therapeutic agent for enhancing efficacy and preventing risks after managing thrombosis.

A Systematic Review of the Quality of Clinical Practice Guidelines for Chronic Limb-Threatening Ischemia.

BACKGROUND: To assess the quality of clinical practice guidelines (CPGs) for chronic limb-threatening ischemia (CLTI) using the Appraisal of Guidelines for Research and Evaluation II instrument. METHODS: A systematic review of Medline, Embase, and online CPG databases was carried out. Four CPGs on CLTI were identified: Global Vascular Guidelines (GVG), European Society of Cardiology (ESC), American College of Cardiology, and National Institute for Health and Care Excellence guidelines on lower limb peripheral arterial disease. Two independent appraisers analyzed the 4 CPGs using the Appraisal of Guidelines for Research and Evaluation II instrument. CPGs were ranked across 6 domains with 23 items that ranged from 1 (strongly disagree) to 7 (strongly agree). A scaled domain score was calculated as a percentage of the maximum possible score achievable. A domain score of ≥50% and an overall average domain score of ≥80% reflected a CPG of adequate quality recommended for use. RESULTS: GVG had the highest overall score (82.9%), as an average of all domains, and ESC had the lowest score (50.2%). GVG and National Institute for Health and Care Excellence guidelines had all domains scoring >50%, while American College of Cardiology had 5 and ESC had 3. Two domains, rigor of development and applicability, scored the lowest among the CPGs. There was a lack of detail in describing systematic methods used in the literature review, how guidelines were formulated with minimal bias, and the planned procedure for updating the guidelines. Implications of guideline application and monitoring of outcomes after implementations were not explicitly discussed. CONCLUSIONS: The GVG guideline published in 2019 discussing CLTI is assessed to be of high quality and recommended for use. This review helps to improve clinical decision-making and quality of future CPGs for CLTI.

Correlation Between Pedal Acceleration Time and Transcutaneous Oxygen Pressures - A Prognostic Tool for Wound Healing in the Diabetic Foot Population.

BACKGROUND: Pedal arch interrogation by ultrasound through systolic acceleration time measurement (Pedal Acceleration Time [PAT]) is a recently described technique that offers valuable insights into foot hemodynamics. Previous studies have demonstrated a correlation between PAT and the ankle-brachial index and PAT has been proposed as a prognostic tool for wound healing in patients with peripheral artery disease. This study aims to assess the correlation between PAT and Transcutaneous Pressure of Oxygen (TcPO2) in the diabetic foot population. METHODS: In this single-center cross-sectional study PAT and TcPO2 were measured in diabetic patients with ischemic foot ulcers. The assessment of wound status was performed between the 12th and 16th week after the first evaluation. The primary outcome was to assess the correlation between the values obtained for PAT and TcPO2. The secondary outcome was to establish a cut-off value for wound healing. RESULTS: Sixty limbs with ischemic foot ulcers were evaluated. The results showed a correlation between PAT and TcPO2 [F (1.52) = 16.928; R2 = 0.246; P < 0.001]. The receiver operating characteristics curve analysis showed an optimal cut-off value at PAT >186 ms for predicting a nonhealing ulcer with a 96% specificity (area under the curve = 0.774; confidence interval 0.648-0.872; P < 0.001). CONCLUSIONS: PAT showed a significant correlation with TcPO2 with high specificity to identify nonhealing foot ulcers due to insufficient foot perfusion with a potential prognostic value in the diabetic foot population.

Proximal Arterial Inflow Revascularization Improves Pedal Arch Quality and Its Impact on Ischemic Diabetic Foot Ulcer Healing.

BACKGROUND: Arterial perfusion is a key factor in diabetic foot ulcer (DFU) healing. Although it is associated with pedal arch patency, not all patients are amenable to pedal artery angioplasty. This study aims to determine the impact of angiographic improvement of the pedal arch quality after proximal arterial inflow revascularization (PAIR) and its association with wound healing. METHODS: One hundred and fifty diabetic patients with tissue loss in 163 limbs who had digital subtraction angiography were studied. Cox regression analysis was used to determine independent predictors of wound healing. Wound healing rates in association with pedal arch patency were calculated by Kaplan-Meier analysis. RESULTS: End-stage renal disease, minor amputation, and complete pedal arch patency were significant independent predictors of wound healing following PAIR with hazard ratios for failure: 3.02 (P = 0.008), 0.54 (P = 0.023), and 0.40 (P = 0.039), respectively. The prevalence of complete pedal arches increased by 24.1% with successful intervention (P < 0.001). The overall rates of wound healing at 6, 12, and 24 months were 36%, 64%, and 72%, respectively. The wound healing rate at 1 year in patients with a complete pedal arch was 73% compared to 45% in those with an absent pedal arch (P = 0.017). CONCLUSIONS: PAIR increases complete pedal arch patency, a significant predictor of wound healing in DFU.

Ocular Ischemic Syndrome and the Role of Carotid Artery Revascularization.

BACKGROUND: Ocular ischemic syndrome (OIS) is a rare presentation of atherosclerotic carotid artery stenosis that can result in permanent visual loss. This severely disabling syndrome remains under diagnosed and undertreated due to lack of awareness; especially since it requires expedited multidisciplinary care. The relevance of early diagnosis and treatment is increasing due to an increasing prevalence of cerebrovascular disease. METHODS: The long-term visual and cerebrovascular outcomes following intervention for nonarteritic OIS, remain poorly described and were the objective of this concise review. We conducted a PubMed search to include all English language publications (cohort studies and case reports) between 2002 and 2023. RESULTS: A total of 33 studies (479 patients) report the outcomes of treatment of OIS with carotid endarterectomy (CEA, 304 patients, 19 studies), and carotid artery stenting (CAS, 175 patients, 14 studies). Visual outcomes were improved or did not worsen in 447 patients (93.3%). No periprocedural stroke was reported. Worsening visual symptoms were rare (35 patients, 7.3%); they occurred in the immediate postoperative period secondary to ocular hypoperfusion (3 patients) and in the late postoperative period due to progression of systemic atherosclerotic disease. Symptomatic recurrence due to recurrent stenosis after CEA was reported in 1 patient (0.21%); this was managed successfully with CAS. None of these studies report the results of transcarotid artery revascularization, the long-term operative outcome or stroke rate. CONCLUSIONS: OIS remains to be an underdiagnosed condition. Early diagnosis and prompt treatment are crucial in reversal or stabilization of OIS symptoms. An expedited multidisciplinary approach between vascular surgery and ophthalmology services is necessary to facilitate timely treatment and optimize outcome. If diagnosed early, both CEA and CAS have been associated with visual improvement and prevention of progressive visual loss.

Treatment Outcomes in Octogenarians with Chronic Limb-Threatening Ischemia after Infrainguinal Bypass Surgery or Endovascular Therapy.

BACKGROUND: This study aimed to analyze the clinical outcomes after revascularization for chronic limb-threatening ischemia (CLTI) in patients aged ≥ 80 years and < 80 years. METHODS: We retrospectively analyzed multicenter data of 789 patients who underwent infrainguinal revascularization for CLTI between 2015 and 2021. The end points were 2-year overall survival (OS), amputation-free survival (AFS), limb salvage (LS), and postoperative complications. RESULTS: A total of 90 patients aged ≥ 80 years and 200 patients aged < 80 years underwent bypass surgery (BSX), and 205 patients aged ≥ 80 years and 294 patients aged < 80 years underwent endovascular therapy (EVT). Before the propensity score matching, multivariate analyses showed that age ≥ 80 years, lower body mass index and serum albumin levels, nonambulatory status, and end-stage renal disease were independent risk factors for 2-year mortality in the BSX and EVT groups. After propensity score matching, the 2-year OS was better in the < 80 years cohort than in the ≥ 80 years cohort in both the BSX and EVT groups (P = 0.018 and P = 0.035, respectively). There was no difference in the 2-year LS rates between the < 80 years and the ≥ 80 years cohorts in both the BSX and EVT groups (P = 0.621 and P = 0.287, respectively). According to the number of risk factors, except for age ≥ 80 years, there was no difference in the 2-year AFS rates between the < 80 years and ≥ 80 years cohorts for the BSX and EVT groups with 0-1 risk factor (P = 0.957 and P = 0.655, respectively). However, the 2-year AFS rate was poor, especially in the ≥ 80 years cohort in the BSX with 2-4 risk factors (P = 0.015). The Clavien-Dindo ≥ IV complication rates tended to be higher in the ≥ 80 years cohort than in the < 80 years cohort only in the BSX with 2-4 risk factors (P = 0.056). CONCLUSIONS: Patients with CLTI aged ≥ 80 years had poorer OS than those aged < 80 years. However, there was no difference in LS between the ≥ 80 years and < 80 years cohorts in both the BSX and EVT groups. Although age ≥ 80 years was associated with poorer OS, patients with 0-1 risk factor may benefit from revascularization, including BSX, because no difference was observed in AFS or Clavien-Dindo ≥ IV complications.

The Use and Impact of Cilostazol on Patients Undergoing Endovascular Peripheral Interventions.

BACKGROUND: Cilostazol is used for the treatment of intermittent claudication. The impact of cilostazol on the outcomes of peripheral vascular interventions (PVIs) remains controversial. This study assesses the use and impact of cilostazol on patients undergoing PVI for peripheral arterial disease (PAD). METHODS: The Vascular Quality Initiative (VQI) database files for PVI were reviewed. Patients with PAD who underwent PVI for chronic limb threatening-ischemia or claudication were included and divided based on the use of cilostazol preoperatively. After propensity matching for patient demographics and comorbidities, the short-term and long-term outcomes of the 2 groups (preoperative cilostazol use versus no preoperative cilostazol use) were compared. The Kaplan-Meier method was used to determine outcomes. RESULTS: A total of 245,309 patients underwent PVI procedures and 6.6% (N = 16,366) were on cilostazol prior to intervention. Patients that received cilostazol were more likely to be male (62% vs 60%; P < 0.001), White (77% vs. 75%; P < 0.001), and smokers (83% vs. 77%; P < 0.001). They were less likely to have diabetes mellitus (50% vs. 56%; P < 0.001) and congestive heart failure (14% vs. 23%; P < 0.001). Patient on cilostazol were more likely to be treated for claudication (63% vs. 40%, P < 0.001), undergo prior lower extremity revascularization (55% vs. 51%, P < 0.001) and less likely to have undergone prior minor and major amputation (10% vs. 19%; P < 0.001) compared with patients who did not receive cilostazol. After 3:1 propensity matching, there were 50,265 patients included in the analysis with no differences in baseline characteristics. Patients on cilostazol were less likely to develop renal complications and more likely to be discharged home. Patients on cilostazol had significantly lower rates of long-term mortality (11.5% vs. 13.4%, P < 0.001 and major amputation (4.0% vs. 4.7%, P = 0.022). However, there were no significant differences in rates of reintervention, major adverse limb events, or patency after PVI. Amputation-free survival rates were significantly higher for patients on cilostazol, after 4 years of follow up (89% vs. 87%, P = 0.03). CONCLUSIONS: Cilostazol is underutilized in the VQI database and seems to be associated with improved amputation-free survival. Cilostazol therapy should be considered in all patients with PAD who can tolerate it prior to PVI.

Outcomes of Alprostadil As an Adjuvant Therapy with Indirect Angiosomal Revascularization in Patients with Critical Limb Ischemia after Failure of Direct Revascularization.

BACKGROUND: This study was carried out to assess the effectiveness of alprostadil (prostaglandin E1) when used as an adjuvant therapy with indirect revascularization in patients with critical limb ischemia (CLI) after the failure of direct revascularization (DR). METHODS: At our centers, 120 patients suffering from infrainguinal peripheral arterial disease with CLI underwent a failed trial of DR procedure, all revascularization procedures were endovascular. Median follow-up was 2 years and 2.5 years for patients with and without diabetes mellitus (DM). In the alprostadil group, the mean age was 63.41 ± 12.52; 36 (60%) for males and 24 (40%) for females. Post-endovascular intervention alprostadil was administrated immediately postoperatively by intravenous infusion of 40 µg alprostadil diluted in 100 ml of normal saline, over 2 hr every 12 hr for 6 days. RESULTS: In the alprostadil group, the mean ± standard deviation (SD) of the baseline ankle-brachial index (ABI) was 0.45 ± 0.175, while the mean ± SD of ABI at the end of our study was 0.65 ± 0.216 with a difference from the baseline of 0.2 ± 0.041 (P value = 0.08, <0.05 meaning that it is significant). Our 1-month primary patency rate was 93.3%, while our 3- and 6-month patency rate was 92.9%. In the control group, the mean ± SD of the baseline ABI was 0.68 ± 0.22, while the mean ± SD of ABI at the end of our study was 0.69 ± 0.23 with a difference from the baseline of 0.01 ± 0.01 (P value >0.05 meaning that it is nonsignificant) 1-month patency rate was 89%, while 3- and 6-month patency rate was 75%. When we compared the patient's leg vessels before and after our intervention, we found that the percentage of the no-runoff-vessels group decreased from 10 (16.7%) to 4 (6.67%). One-runoff-vessel group percentage dropped from 40 (66.7%) to 36 (60%), whereas, in the two-runoff-vessel group, the percentage increased from 10 (16.7%) to 20 (33.3%). We evaluate leg arteries; we do no pedal arch intervention in the alpostradil group. Out of the total of 60 patients, limb salvage occurred in 58 (96.7%) patients, and 2 (3.3%) patients underwent below-the-knee amputation before the study ended. CONCLUSIONS: Our results show the efficacy and safety of alprostadil as an adjuvant therapy with indirect angiosomal revascularization in patients with tissue loss due to CLI.

Influence of a Novel Morphology-Driven Classification on Limb Salvage after Isolated Tibial Intervention for Chronic Limb Threatening Ischemia.

BACKGROUND: Infra-popliteal interventions for chronic limb-threatening ischemia (CLTI) can be impacted by the morphology of the tibial vessels. The aim of this study was to examine the impact of a novel morphology-driven classification on the outcomes of isolated tibial intervention for CLTI. METHODS: A database of patients undergoing isolated tibial interventions for CLTI at a single center between 2010 and 2020 was retrospectively queried. Patients with isolated infra-popliteal disease were identified, and their anatomy was scored as present or absent for lesion calcification (1 point), target vessel diameter<3.0 mm (1 point), lesion length>300 mm (1 point), and poor pedal runoff score (1 point). Patients were then divided into 3 groups: low risk (0 or 1 points), moderate risk (2 points), and high risk (3 or 4 points). Intention to treat analysis by the patient was performed. Limb-based patency (the absence of reintervention, occlusion, critical stenosis [>70%], or hemodynamic compromise with ongoing symptoms of CLTI as it related to the patency of the preoperatively determined target artery pathway) was assessed. Patient-oriented outcomes of amputation-free survival (AFS; survival without major amputation) and freedom from major adverse limb events (MALE; above ankle amputation of the index limb or major reintervention: new bypass graft, jump/interposition graft revision) were evaluated. RESULTS: 1,607 patients (55% male, average age 60 years, 3,846 vessels) underwent tibial intervention for CLTI. The majority of the patients were diabetic and of Hispanic origin. Morphologically, 27%, 31%, and 42% of the vessels were categorized as low risk, moderate risk, and high risk, respectively. There was a significant worsening of the infra-popliteal Global Limb Anatomic Staging System (GLASS) grading as the morphological risk increased. The 30-day major adverse cardiac events (MACE) were equivalent across the groups and were under the stated objective performance goal (OPG) of ≤10%. In contrast, both the 30-day MALE and the 30-day major amputations were significantly different across the groups, with the low-risk group remaining under the OPG of ≤9% and ≤4%, respectively, while the moderate risk and high risk exceeded the goal threshold. For the OPG, freedom from MALE was 60 ± 5%, 46 ± 5%, and 22 ± 9% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.008). Overall AFS was 55 ± 5%, 37 ± 6%, and 18 ± 7% at 5 years for low-, moderate-, and high-risk groups, respectively (mean ± standard error of the mean; P = 0.003). CONCLUSIONS: Tibial anatomic morphology impacts isolated tibial endovascular intervention with adverse morphology associated with poorer short- and long-term outcomes. Risk stratification based on anatomic predictors should be an additional consideration as one intervenes on infra-popliteal vessels for CLTI.

Acute aortic occlusion: A narrative review for emergency clinicians.

INTRODUCTION: Acute aortic occlusion (AAO) is a rare but serious condition associated with significant morbidity and mortality. OBJECTIVE: This review provides an emergency medicine focused evaluation of AAO, including presentation, assessment, and emergency department (ED) management based on current evidence. DISCUSSION: AAO refers to obstruction of blood flow through the aorta due to either thrombosis or embolism. This condition primarily affects older adults ages 60-70 with cardiovascular comorbidities and most commonly presents with signs and symptoms of acute limb ischemia, though the gastrointestinal tract, kidneys, and spinal cord may be affected. The first line imaging modality includes computed tomography angiography of the chest, abdomen, and pelvis. ED resuscitative management consists of avoiding extremes of blood pressure or heart rate, maintaining normal oxygen saturation and euvolemic status, anticoagulation with heparin, and pain control. Emergent consultation with the vascular surgery specialist is recommended to establish a plan for restoration of perfusion to ischemic tissues via endovascular or open techniques. High rates of baseline comorbidities present in the affected population as well as ischemic and reperfusion injuries place AAO patients at high risk for complications in an immediate and delayed fashion after surgical management. CONCLUSIONS: An understanding of AAO can assist emergency clinicians in diagnosing and managing this rare but devastating disease.

Open Surgical Therapy for Peripheral Artery Disease.

PURPOSE OF REVIEW: The surgical management of symptomatic peripheral artery disease (PAD) has changed in the last few decades. Improvement in endovascular technology has resulted in more complex lesion once reserved for open surgery being addressed in an endovascular fashion. Even with these advances, there are lesions and patients that are better managed with an open surgical procedure. The aim of this review is to describe the most commonly performed open surgical procedures for PAD. RECENT FINDINGS: The recently published Best Endovascular versus Best Surgical Therapy (BEST-CLI) trial was an international, prospective, randomized controlled trial that aimed to investigate which revascularization (endovascular vs. surgical bypass) approach was superior for limb salvage. The evidence supports an open surgical bypass as an initial approach. The advancements made in the surgical management of PAD have provided options for patients who were once deemed poor surgical candidates. The goal continues to be utilization of the best available tools to address patient disease. In this current era, it is important to be familiar with the open surgical therapies.

Therapeutic Effects of Anti-Inflammatory and Anti-Oxidant Nutritional Supplementation in Retinal Ischemic Diseases.

Appropriate nutrients are essential for cellular function. Dietary components can alter the risk of systemic metabolic diseases, including cardiovascular diseases, cancer, diabetes, and obesity, and can also affect retinal diseases, including age-related macular degeneration, diabetic retinopathy, and glaucoma. Dietary nutrients have been assessed for the prevention or treatment of retinal ischemic diseases and the diseases of aging. In this article, we review clinical and experimental evidence concerning the potential of some nutritional supplements to prevent or treat retinal ischemic diseases and provide further insights into the therapeutic effects of nutritional supplementation on retinopathies. We will review the roles of nutrients in preventing or protecting against retinal ischemic diseases.

Cell Therapy of Vascular and Neuropathic Complications of Diabetes: Can We Avoid Limb Amputation?

Globally, a leg is amputated approximately every 30 seconds, with an estimated 85 percent of these amputations being attributed to complications arising from diabetic foot ulcers (DFU), as stated by the American Diabetes Association. Peripheral arterial disease (PAD) is a risk factor resulting in DFU and can, either independently or in conjunction with diabetes, lead to recurring, slow-healing ulcers and amputations. According to guidelines amputation is the recommended treatment for patients with no-option critical ischemia of the limb (CTLI). In this article we propose cell therapy as an alternative strategy for those patients. We also suggest the optimal time-frame for an effective therapy, such as implanting autologous mononuclear cells (MNCs), autologous and allogeneic mesenchymal stromal cells (MSC) as these treatments induce neuropathy relief, regeneration of the blood vessels and tissues, with accelerated ulcer healing, with no serious side effects, proving that advanced therapy medicinal product (ATMPs) application is safe and effective and, hence, can significantly prevent limb amputation.