Evolution of distal limb perfusion management in adult peripheral venoarterial extracorporeal membrane oxygenation with femoral artery cannulation.

Limb ischaemia is a clinically relevant complication of venoarterial extracorporeal membrane oxygenation (VA ECMO) with femoral artery cannulation. No selective distal perfusion or other advanced techniques were used in the past to maintain adequate distal limb perfusion. A more recent trend is the shift from the reactive or emergency management to the pro-active or prophylactic placement of a distal perfusion cannula to avoid or reduce limb ischaemia-related complications. Multiple alternative cannulation techniques to the distal perfusion cannula have been developed to maintain distal limb perfusion, including end-to-side grafting, external or endovascular femoro-femoral bypass, retrograde limb perfusion (e.g., via the posterior tibial, dorsalis pedis or anterior tibial artery), and, more recently, use of a bidirectional cannula. Venous congestion has also been recognized as a potential contributing factor to limb ischaemia development and specific techniques have been described with facilitated venous drainage or bilateral cannulation being the most recent, to reduce or avoid venous stasis as a contributor to impaired limb perfusion. Advances in monitoring techniques, such as near-infrared spectroscopy and duplex ultrasound analysis, have been applied to improve decision-making regarding both the monitoring and management of limb ischaemia. This narrative review describes the evolution of techniques used for distal limb perfusion during peripheral VA ECMO.

Clinical Performance of the Low Profile Zenith Alpha Abdominal Endovascular Graft: 2 Year Results from the ZEPHYR Registry.

OBJECTIVE: The midterm outcomes of the low profile Zenith Alpha Abdominal Endovascular Graft from the ZEnith alPHa for aneurYsm Repair (ZEPHYR) registry are reported. METHODS: The ZEPHYR registry is a physician initiated, multicentre, non-randomised, core laboratory controlled, prospective registry. Inclusion criteria were patients with a non-ruptured abdominal aortic aneurysm with a maximum diameter ≥ 50 mm or enlargement > 5 mm within 6 months, with a site reported infrarenal neck length of ≥ 10 mm and with the intention to electively implant the Zenith Alpha abdominal endograft. Patients from 14 sites across Germany, Belgium, and the Netherlands were included. The primary endpoint was treatment success, defined as technical success and clinical success. Technical success was defined as successful delivery and deployment of the endograft in the planned position without unintentional coverage of internal iliac or renal arteries, with successful removal of the delivery system. Clinical success was defined as freedom from aneurysm sac expansion > 5 mm, type I or type III endoleaks, aneurysm rupture, stent graft migration > 10 mm, open conversion, and stent graft occlusion. RESULTS: Three hundred and forty-seven patients were included in the ZEPHYR registry. The median clinical follow up was 743 days (interquartile range [IQR] 657, 806) with a median imaging follow up of 725 days (IQR 408, 788). Treatment success at 6 months, 1, and 2 years was 92.5%, 90.4%, and 85.3%, respectively. Freedom from secondary intervention was 94.3%, 93.4%, and 86.9%, respectively. The predominant reason for secondary intervention was limb complications. Freedom from limb occlusion (per patient) at 6 months, 1, and 2 years was 97.2%, 95.8%, and 92.5%, respectively. Univariable and multivariable Cox regression analyses could not identify any independent predictor for limb complications. CONCLUSION: While treatment success is comparable with other commercially available grafts, the rate of limb complications at 2 years is of concern. The manufacturer's instructions for use should be followed closely. Further studies are necessary to investigate the root cause of the increased rate of limb complications with the Zenith Alpha Abdominal Endovascular Graft.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms.

OBJECTIVE: The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy. METHODS: The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence. RESULTS: A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed. CONCLUSION: The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

Identification of a gene network driving the attenuated response to lipopolysaccharide of monocytes from hypertensive coronary artery disease patients.

Introduction: The impact of cardiovascular disease (CVD) risk factors, encompassing various biological determinants and unhealthy lifestyles, on the functional dynamics of circulating monocytes-a pivotal cell type in CVD pathophysiology remains elusive. In this study, we aimed to elucidate the influence of CVD risk factors on monocyte transcriptional responses to an infectious stimulus. Methods: We conducted a comparative analysis of monocyte gene expression profiles from the CTMM - CIRCULATING CELLS Cohort of coronary artery disease (CAD) patients, at baseline and after lipopolysaccharide (LPS) stimulation. Gene co-expression analysis was used to identify gene modules and their correlations with CVD risk factors, while pivotal transcription factors controlling the hub genes in these modules were identified by regulatory network analyses. The identified gene module was subjected to a drug repurposing screen, utilizing the LINCS L1000 database. Results: Monocyte responsiveness to LPS showed a highly significant, negative correlation with blood pressure levels (ρ< -0.4; P<10-80). We identified a ZNF12/ZBTB43-driven gene module closely linked to diastolic blood pressure, suggesting that monocyte responses to infectious stimuli, such as LPS, are attenuated in CAD patients with elevated diastolic blood pressure. This attenuation appears associated with a dampening of the LPS-induced suppression of oxidative phosphorylation. Finally, we identified the serine-threonine inhibitor MW-STK33-97 as a drug candidate capable of reversing this aberrant LPS response. Conclusions: Monocyte responses to infectious stimuli may be hampered in CAD patients with high diastolic blood pressure and this attenuated inflammatory response may be reversed by the serine-threonine inhibitor MW-STK33-97. Whether the identified gene module is a mere indicator of, or causal factor in diastolic blood pressure and the associated dampened LPS responses remains to be determined.

FLOW: Flow dysfunction of hemodialysis vascular access: A randomized controlled trial on the effectiveness of surveillance of arteriovenous fistulas and grafts.

INTRODUCTION: It is assumed that identification and correction of asymptomatic stenoses in the vascular access circuit will prevent thrombosis that would require urgent intervention to continue hemodialysis treatment. However, the evidence base for this assumption is limited. Recent international clinical practice guidelines reach different conclusions on the use of surveillance for vascular access flow dysfunction and recommend further research to inform clinical practice. METHODS: The FLOW trial is a double-blind, multicenter, randomized controlled trial with a 1:1 individual participant treatment allocation ratio over two study arms. In the intervention group, only symptomatic vascular access stenoses detected by clinical monitoring are treated, whereas in the comparison group asymptomatic stenoses detected by surveillance using monthly dilution flow measurements are treated as well. Hemodialysis patients with a functional arteriovenous vascular access are enrolled. The primary outcome is the access-related intervention rate that will be analyzed using a general linear model with Poisson distribution. Secondary outcomes include patient satisfaction, access-related serious adverse events, and quality of the surveillance process. A cost effectiveness analysis and budget impact analysis will also be conducted. The study requires 828 patient-years of follow-up in 417 participants to detect a difference of 0.25 access-related interventions per year between study groups. DISCUSSION: As one of the largest randomized controlled trials assessing the clinical impact of vascular access surveillance using a strong double-blinded study design, we believe the FLOW trial will provide much-needed evidence to improve vascular access care for hemodialysis patients.

End of Life Care for Unplanned Vascular Admissions.

BACKGROUND: Unplanned vascular admissions have a high mortality. Previous studies have indicated that end of life care (EoLC) among this group of patients is low but there exist limited data on EoLC in the United Kingdom. The aim of this study was to evaluate the quality and predictors of EoLC for unplanned vascular admissions to a tertiary center in the United Kingdom. METHODS: This was a retrospective single-center cohort study of unplanned vascular surgery admissions from August 1, 2019 to January 22, 2020. Data on patient demographics, markers of quality of palliative care, mortality, and cause of death of unplanned admission to the vascular surgery department were collected from hospital and general practitioner records and evaluated against EoLC to evaluate predictors and efficacy of EoLC. Quality of palliative care markers included documentation of preferred place of death and care priorities, time spent in hospital and the intensive care unit toward the end of life, and realization of documented care objectives. EoLC input was defined as a dedicated palliative care consultation (PCC) by a palliative care professional, medical doctor, surgeon, or advanced care practitioner. We also conducted a subgroup analysis of patients within this group with chronic limb-threatening ischemia (CLTI), diabetic foot, and ruptured aortic aneurysms, as all patients in this group should be offered EoLC according to international guidelines. RESULTS: One-hundred and fifty patients were included. Median age at presentation was 70.5 years, and the cohort consisted of mostly men (72%). CLTI (31%) was the most common reason for admission. Surgical intervention was carried out in 60% of patients. Two-year mortality was 36%, and pneumonia (22%) was the most common cause of death. Seven percent of patients received PCC, which occurred a median of 10 days before death. Only a minority of patients had preferred place of care/death (14%), care priorities (37%), and family involvement during advance care planning (17%) documented in their notes; 29% of patients had Recommended Summary Plan for Emergency Care and Treatment forms in place. A diagnosis of left ventricular systolic dysfunction, chronic kidney disease, and increasing age predicted Recommended Summary Plan for Emergency Care and Treatment form completion. Patients with PCC were more likely to have advance care planning, but this did not translate into improvements in the other markers of quality of palliative and, consequently, EoLC. CONCLUSIONS: EoLC was insufficient and of low quality despite a high mortality in this group. Clinical guidelines and pathways are needed to ensure these patients are considered for EoLC and those with CLTI, diabetic foot sepsis or ruptured abdominal aortic aneurysms are offered it by default. Further research is needed to help identify vascular patients who would benefit from EoLC earlier to improve quality at end of life.

Bilateral Femoral Cannulation Is Associated With Reduced Severe Limb Ischemia-Related Complications Compared With Unilateral Femoral Cannulation in Adult Peripheral Venoarterial Extracorporeal Membrane Oxygenation: Results From the Extracorporeal Life Support Registry.

OBJECTIVES: Peripheral venoarterial extracorporeal membrane oxygenation (ECMO) with femoral access is obtained through unilateral or bilateral groin cannulation. Whether one cannulation strategy is associated with a lower risk for limb ischemia remains unknown. We aim to assess if one strategy is preferable. DESIGN: A retrospective cohort study based on the Extracorporeal Life Support Organization registry. SETTING: ECMO centers worldwide included in the Extracorporeal Life Support Organization registry. PATIENTS: All adult patients (≥ 18 yr) who received peripheral venoarterial ECMO with femoral access and were included from 2014 to 2020. INTERVENTIONS: Unilateral or bilateral femoral cannulation. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the occurrence of limb ischemia defined as a composite endpoint including the need for a distal perfusion cannula (DPC) after 6 hours from implantation, compartment syndrome/fasciotomy, amputation, revascularization, and thrombectomy. Secondary endpoints included bleeding at the peripheral cannulation site, need for vessel repair, vessel repair after decannulation, and in-hospital death. Propensity score matching was performed to account for confounders. Overall, 19,093 patients underwent peripheral venoarterial ECMO through unilateral ( n = 11,965) or bilateral ( n = 7,128) femoral cannulation. Limb ischemia requiring any intervention was not different between both groups (bilateral vs unilateral: odds ratio [OR], 0.92; 95% CI, 0.82-1.02). However, there was a lower rate of compartment syndrome/fasciotomy in the bilateral group (bilateral vs unilateral: OR, 0.80; 95% CI, 0.66-0.97). Bilateral cannulation was also associated with lower odds of cannulation site bleeding (bilateral vs unilateral: OR, 0.87; 95% CI, 0.76-0.99), vessel repair (bilateral vs unilateral: OR, 0.55; 95% CI, 0.38-0.79), and in-hospital mortality (bilateral vs unilateral: OR, 0.85; 95% CI, 0.81-0.91) compared with unilateral cannulation. These findings were unchanged after propensity matching. CONCLUSIONS: This study showed no risk reduction for overall limb ischemia-related events requiring DPC after 6 hours when comparing bilateral to unilateral femoral cannulation in peripheral venoarterial ECMO. However, bilateral cannulation was associated with a reduced risk for compartment syndrome/fasciotomy, lower rates of bleeding and vessel repair during ECMO, and lower in-hospital mortality.

Surveillance After Surgical and Endovascular Treatment for Peripheral Artery Disease: a Dutch Survey.

OBJECTIVE: At present, there is no clear, optimal approach to surveillance after invasive treatment of peripheral artery disease (PAD) in terms of modality, duration, clinical benefit, and cost effectiveness. The ongoing debate on the clinical benefit and cost effectiveness of standard surveillance creates a clear knowledge gap and may result in overtreatment or undertreatment. In this study, a survey was conducted among vascular surgeons in the Netherlands to assess the currently applied surveillance programmes. METHODS: All vascular surgeons from the Dutch Society for Vascular Surgery received an online survey on follow up after open and endovascular revascularisation in patients with PAD. Surveillance was defined as at least one follow up visit after intervention with or without additional imaging or ankle brachial index (ABI) measurement. Ten types of PAD intervention were surveyed. RESULTS: Surveys were returned by 97 (46.2%) of 210 vascular surgeons, and 76% reported using a routine follow up protocol after an invasive intervention. Clinical follow up only is most commonly performed after femoral endarterectomy (53%). After peripheral bypass surgery, clinical follow up only is applied rarely (4 - 8%). In six of the 10 interventions surveyed, duplex ultrasound (DUS) was the most used imaging modality for follow up. After bypass surgery, 76 - 86% of vascular surgeons perform DUS with or without ABI measurement. After endovascular interventions, 21 - 60% performed DUS surveillance. Lifelong surveillance is most often applied after aortobifemoral bypass (57%). Surveillance frequency and duration vary greatly within the same intervention. Frequencies range from every three or six months to annually. Duration ranges from one time surveillance to lifelong follow up. CONCLUSION: There is significant practice variation in surveillance after surgical and endovascular treatment of patients with PAD in the Netherlands. Prospective studies to evaluate treatment outcomes and to define the clinical need and cost effectiveness of standardised surveillance programmes for patients with PAD are recommended.

GM-CSF-activated STAT5A regulates macrophage functions and inflammation in atherosclerosis.

Introduction: Inhibition of STAT5 was recently reported to reduce murine atherosclerosis. However, the role of STAT5 isoforms, and more in particular STAT5A in macrophages in the context of human atherosclerosis remains unknown. Methods and results: Here, we demonstrate reciprocal expression regulation of STAT5A and STAT5B in human atherosclerotic lesions. The former was highly upregulated in ruptured over stable plaque and correlated with macrophage presence, a finding that was corroborated by the high chromosomal accessibility of STAT5A but not B gene in plaque macrophages. Phosphorylated STAT5 correlated with macrophages confirming its activation status. As macrophage STAT5 is activated by GM-CSF, we studied the effects of its silencing in GM-CSF differentiated human macrophages. STAT5A knockdown blunted the immune response, phagocytosis, cholesterol metabolism, and augmented apoptosis terms on transcriptional levels. These changes could partially be confirmed at functional level, with significant increases in apoptosis and decreases in lipid uptake and IL-6, IL-8, and TNFa cytokine secretion after STAT5A knockdown. Finally, inhibition of general and isoform A specific STAT5 significantly reduced the secretion of TNFa, IL-8 and IL-10 in ex vivo tissue slices of advanced human atherosclerotic plaques. Discussion: In summary, we identify STAT5A as an important determinant of macrophage functions and inflammation in the context of atherosclerosis and show its promise as therapeutic target in human atherosclerotic plaque inflammation.

The Maastricht Acquisition Platform for Studying Mechanisms of Cell-Matrix Crosstalk (MAPEX): An Interdisciplinary and Systems Approach towards Understanding Thoracic Aortic Disease.

Current management guidelines for ascending thoracic aortic aneurysms (aTAA) recommend intervention once ascending or sinus diameter reaches 5-5.5 cm or shows a growth rate of >0.5 cm/year estimated from echo/CT/MRI. However, many aTAA dissections (aTAAD) occur in vessels with diameters below the surgical intervention threshold of <55 mm. Moreover, during aTAA repair surgeons observe and experience considerable variations in tissue strength, thickness, and stiffness that appear not fully explained by patient risk factors. To improve the understanding of aTAA pathophysiology, we established a multi-disciplinary research infrastructure: The Maastricht acquisition platform for studying mechanisms of tissue-cell crosstalk (MAPEX). The explicit scientific focus of the platform is on the dynamic interactions between vascular smooth muscle cells and extracellular matrix (i.e., cell-matrix crosstalk), which play an essential role in aortic wall mechanical homeostasis. Accordingly, we consider pathophysiological influences of wall shear stress, wall stress, and smooth muscle cell phenotypic diversity and modulation. Co-registrations of hemodynamics and deep phenotyping at the histological and cell biology level are key innovations of our platform and are critical for understanding aneurysm formation and dissection at a fundamental level. The MAPEX platform enables the interpretation of the data in a well-defined clinical context and therefore has real potential for narrowing existing knowledge gaps. A better understanding of aortic mechanical homeostasis and its derangement may ultimately improve diagnostic and prognostic possibilities to identify and treat symptomatic and asymptomatic patients with existing and developing aneurysms.

Outcomes of Elective and Non-elective Fenestrated-branched Endovascular Aortic Repair for Treatment of Thoracoabdominal Aortic Aneurysms.

OBJECTIVE: To describe outcomes after elective and non-elective fenestrated-branched endovascular aortic repair (FB-EVAR) for thoracoabdominal aortic aneurysms (TAAAs). BACKGROUND: FB-EVAR has been increasingly utilized to treat TAAAs; however, outcomes after non-elective versus elective repair are not well described. METHODS: Clinical data of consecutive patients undergoing FB-EVAR for TAAAs at 24 centers (2006-2021) were reviewed. Endpoints including early mortality and major adverse events (MAEs), all-cause mortality, and aortic-related mortality (ARM), were analyzed and compared in patients who had non-elective versus elective repair. RESULTS: A total of 2603 patients (69% males; mean age 72±10 year old) underwent FB-EVAR for TAAAs. Elective repair was performed in 2187 patients (84%) and non-elective repair in 416 patients [16%; 268 (64%) symptomatic, 148 (36%) ruptured]. Non-elective FB-EVAR was associated with higher early mortality (17% vs 5%, P <0.001) and rates of MAEs (34% vs 20%, P <0.001). Median follow-up was 15 months (interquartile range, 7-37 months). Survival and cumulative incidence of ARM at 3 years were both lower for non-elective versus elective patients (50±4% vs 70±1% and 21±3% vs 7±1%, P <0.001). On multivariable analysis, non-elective repair was associated with increased risk of all-cause mortality (hazard ratio, 1.92; 95% CI] 1.50-2.44; P <0.001) and ARM (hazard ratio, 2.43; 95% CI, 1.63-3.62; P <0.001). CONCLUSIONS: Non-elective FB-EVAR of symptomatic or ruptured TAAAs is feasible, but carries higher incidence of early MAEs and increased all-cause mortality and ARM than elective repair. Long-term follow-up is warranted to justify the treatment.

Evolution of the covered endovascular reconstruction of the aortic bifurcation technique for complex aorto-iliac occlusive disease.

INTRODUCTION: The covered endovascular reconstruction of aortic bifurcation (CERAB) technique was introduced as a more anatomical and physiological configuration of stents to overcome the limits of standard endovascular technique with kissing stenting in terms of patency and reintervention rates in the treatment of complex aorto-iliac occlusive disease in particular when the aortic bifurcation is involved. The purpose of this systematic review is to report the evolution of this technique during recent years. EVIDENCE ACQUISITION: Data were retrieved from retrospective studies and case series excluding letters, editorial, and reviews conducted from 2000 to September 2022. EVIDENCE SYNTHESIS: The literature analysis provided data on the evolution of CERAB technique and the current evidence about clinical results. CONCLUSIONS: Since its introduction in 2009, CERAB technique has grown as a safe and effective endovascular therapeutic option for aorto-iliac occlusive disease. Data from prospective multicenter registries with dedicated stent grafts and comparative trials are needed to validate the technique.

Editor's Choice - Quality of Life after Stenting for Iliofemoral Venous Obstruction: A Randomised Controlled Trial with One Year Follow Up.

OBJECTIVE: Deep venous obstruction (DVO) is a great burden on the healthcare system and patients' quality of life (QoL). Case series show stenting is safe and effective, however most studies lack control groups and QoL changes have not been compared with conventional treatment. The aim was to assess the difference in QoL changes from baseline to 12 months between stent and conventionally treated patients with DVO. METHODS: Subjects > 18 years old with DVO due to post-thrombotic (PTS) or non-thrombotic iliac vein lesions (NIVLs) in a tertiary hospital were prospectively randomised to best medical therapy (BMT) or stent placement with BMT in a ratio 2:1, stratified for PTS or NIVL. The primary outcome was the between group difference in VEINES-QoL scores change from baseline to 12 months after treatment. Secondary outcomes included the difference in score changes for EuroQoL 5-Dimension 5 Level (EQ-5D-5L), Pain Disability Index (PDI), Venous Clinical Severity Score (VCSS), and the Villalta score. RESULTS: After three years, the inclusion rate dropped to almost zero, therefore the study had to be stopped. Sixty-three patients were randomised to either the stent (n = 42) or control group (n = 21). Overall, 50 patients had available data for primary outcome analysis. The adjusted mean difference between 12 month scores for VEINES-QoL and VEINES-Sym was 8.07 (95% CI 3.04 - 13.09) and 5.99 (95% CI 0.75 - 11.24) (p = .026), respectively, in favour of the stent group. The differences were significant, but a pre-defined meaningful 14 point improvement in QoL was not reached. The mean difference between 12 month scores for VCSS was -2.93 (95% CI -5.71 - 0.16, p = .040), -11.83 (95% CI -20.81 - 2.86, p = .011) for PDI, 0.015 (95% CI -0.12 - 0.15, p = .82) for the EQ-5D index, and -2.99 (95% CI -7.28 - 1.30, p = .17) for the Villalta score. CONCLUSION: Symptomatic patients with DVO who received dedicated venous stents had significantly higher VEINES-QoL/Sym scores at 12 months compared with the control group, but the between group difference was lower than the pre-specified clinically relevant QoL difference of at least 14 points. STUDY REGISTRATION NUMBER: NCT03026049.

Microvesicle-Mediated Tissue Regeneration Mitigates the Effects of Cellular Ageing.

Extracellular vesicles (EVs), comprising microvesicles (MVs) and exosomes (Exos), are membranous vesicles secreted by cells which mediate the repair of cellular and tissue damage via paracrine mechanisms. The action of EVs under normative and morbid conditions in the context of ageing remains largely unexplored. We demonstrate that MVs, but not Exos, from Pathfinder cells (PCs), a putative stem cell regulatory cell type, enhance the repair of human dermal fibroblast (HDF) and mesenchymal stem cell (MSC) co-cultures, following both mechanical and genotoxic stress. Critically, this effect was found to be both cellular age and stress specific. Notably, MV treatment was unable to repair mechanical injury in older co-cultures but remained therapeutic following genotoxic stress. These observations were further confirmed in human dermal fibroblast (HDF) and vascular smooth muscle cell (VSMC) co-cultures of increasing cellular age. In a model of comorbidity comprising co-cultures of HDFs and highly senescent abdominal aortic aneurysm (AAA) VSMCs, MV administration appeared to be senotherapeutic, following both mechanical and genotoxic stress. Our data provide insights into EVs and the specific roles they play during tissue repair and ageing. These data will potentiate the development of novel cell-free therapeutic interventions capable of attenuating age-associated morbidities and avoiding undesired effects.