Techniques and Technologies to Improve Vein Graft Patency in Coronary Surgery.

Vein grafts are the most used conduits in coronary artery bypass grafting (CABG), even though many studies have suggested their lower patency compared to arterial alternatives. We have reviewed the techniques and technologies that have been investigated over the years with the aim of improving the quality of these conduits. We found that preoperative and postoperative optimal medical therapy and no-touch harvesting techniques have the strongest evidence for optimizing vein graft patency. On the other hand, the use of venous external support, endoscopic harvesting, vein preservation solution and anastomosis, and graft configuration need further investigation. We have also analyzed strategies to treat vein graft failure: when feasible, re-doing the CABG and native vessel primary coronary intervention (PCI) are the best options, followed by percutaneous procedures targeting the failed grafts.

Predictors of Survival After Heart Transplant in the New Allocation System: A UNOS Database Analysis.

Clinical predictors of posttransplant graft loss since the United Network for Organ Sharing (UNOS) heart allocation system change have not been well characterized. Single organ adult heart transplants from the UNOS database were identified (n = 10,252) and divided into a test cohort (n = 6,869, 67%) and validation cohort (n = 3,383, 33%). A Cox regression analysis was performed on the test cohort to identify recipient and donor risk factors for posttransplant graft loss. Based on the risk factors, a score (max 16) was developed to classify patients in the validation cohort into risk groups of low (≤1), mid (2-3), high (≥4) risk. Recipient factors of advanced age, Black race, recipient blood group O, diabetes, etiology of heart failure, renal dysfunction, elevated bilirubin, redo-transplantation, elevated pulmonary artery pressure, transplant with a durable ventricular assist device, or transplant on extracorporeal membrane oxygenation (ECMO) or ventilator were associated with more posttransplant graft loss. Donor factors of ischemic time and donor age were also associated with outcomes. One year graft survival for the low-, mid-, high-risk groups was 94%, 91%, and 85%, respectively. In conclusion, easily obtainable clinical characteristics at time of heart transplant can predict posttransplant outcomes in the current era.

Optimizing Safety and Success: The Advantages of Bloodless Cardiac Surgery. A Systematic Review and Meta-Analysis of Outcomes in Jehovah's Witnesses.

Transfusions are extremely frequent after cardiac surgery, and they have a considerable economic burden and impact on outcomes. Optimal patient blood management could play a fundamental role in reducing the rate of transfusion and Jehovah's Witnesses (JW) represent the ideal surrogate study population. This meta-analysis compares outcomes of JWs and non-JWs' patients undergoing cardiac surgery, assessing the safety of a bloodless cardiac surgery. A scoping review was conducted using a search strategy for studies assessing outcomes of JW undergoing cardiac surgery. The primary outcome was perioperative mortality, and a random-effects meta-analysis was performed. Ten studies were included in our meta-analysis, involving 780 JW patients refusing any type of transfusion ("JW") and 1182 patients accepting transfusion if needed ("non-JW"). 86% of non-JW patients received at least 1 transfusion. There was no significant difference in terms of perioperative mortality (OR 0.91; 95% CI 0.55-1.52; p = 0.72). The volume blood loss was significantly less in the JW (p = 0.001), while the rate of reoperation for bleeding was also lower, but not statistically significative, in the JW (p = 0.16). Both preoperative and postoperative hemoglobin and hematocrit were significantly higher in the JW. Therefore, we concluded that bloodless cardiac surgery is safe and early outcomes are similar between JW and non-JW patients: optimal patient blood management is fundamental in guarantying these results. Further studies are needed to assess if a limitation of transfusion could have a positive long-term impact on outcomes.

Surgical Ablation for Atrial Fibrillation During Mitral Valve Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Although surgical ablation has been shown to produce excellent outcomes at follow-up for patients with atrial fibrillation who underwent mitral valve replacement/repair (MVR), this procedure is not commonly performed. Our objective was to conduct a systematic review and meta-analysis to evaluate the outcomes of concomitant surgical ablation during MVR. Three databases were systematically reviewed for randomized clinical trials published by August 2022. The primary outcome was sinus rhythm (SR) at 12 months. Secondary outcomes included SR at discharge and 6 months, all-cause mortality, permanent pacemaker implantation, and stroke and thromboembolic events. A random-effects meta-analysis was performed, calculating odds ratios (ORs) for each outcome. Thirteen studies were included, involving 1,089 patients comparing patients who underwent either isolated MVR ("MVR-only") or concomitant surgical ablation during MVR ("MVR+Ablation"). The odds of SR were significantly higher in the MVR+Ablation group at discharge (OR 9.62, 95% confidence interval [CI] 4.87 to 19.02, I2 = 55%), at 6-month follow-up (OR 7.21, 95% CI 4.30 to 12.11, I2 = 34%), and at 1-year follow-up (OR 8.41, 95% CI 5.14 to 13.77, I2 = 48%). All-cause mortality was not different in the groups, as were stroke and thromboembolic events, whereas the odds of permanent pacemaker implantation were slightly higher in the MVR+Ablation group (OR 1.87, 95% CI 1.11 to 3.17, I2 = 0%). Concomitant surgical ablation during MVR showed excellent outcomes at short-term follow-up, despite a slightly higher rate of permanent pacemaker implantation. Further studies with longer follow-ups are needed to assess if the SR is maintained over the years.

del Nido versus hematic cardioplegia in minimally invasive aortic valve surgery.

BACKGROUND: The quality of a myocardial protection of a single-dose del Nido cardioplegia versus multiple dose blood-based cardioplegia on myocardial injury, outcomes and operative times in patients undergoing minimally invasive aortic valve replacement is basically unreported. METHODS AND RESULTS: Preoperative and post-operative data, as well as technical details from isolated minimally invasive aortic valve replacements, performed using single-dose or multiple-dose cardioplegia were prospectively collected and retrospectively analysed. A total of 110 patients undergoing minimally invasive valve replacements at our institution composed two groups: 55 patients in the blood cardioplegia group (BloCa) and 55 in the del Nido group (DeNiCa). The two-matched groups were comparable in terms of preoperative variables. In the DeNiCa group, there was a statistically significant less need for cardiac defibrillation after aortic cross-clamp release (p < 0.001). Moreover, the BloCa group received intraoperatively more blood transfusions (p = 0.001) and more insulin administration for higher glucose levels (p < 0.001). The BloCa group showed higher intraoperative lactate levels (p = 0.01). Need for post-operative inotropic and vasoactive support, Creatine Kinase-MB levels after 6 and 12 h, onset of post-operative atrial fibrillation and length of stay were similar. No deaths occurred in neither groups. CONCLUSION: Single-dose del Nido cardioplegia in the setting of minimally invasive aortic surgery seems to offer adequate myocardial protection, comparable to multiple dose hematic cardioplegia. It has been documented a lower peri-operative need of defibrillation after cross-clamp release, lactate- and glucose peak values, as well as less blood transfusions compared to blood cardioplegic strategy.

Left ventricular assist device exchange: a review of indications, operative procedure, and outcomes.

The use of left ventricular assist devices (LVADs) is intended to treat patients with end-stage heart failure. Owing to technological advances, these devices are becoming more durable. However, LVADs may need to be exchanged when complications arise and heart transplantation is not possible. Indications for LVAD exchange (LVADE) include device thrombosis, device infections, and pump component failure. LVADE has historically been associated with a high risk of morbidity and mortality. In this review, we discuss the indications of LVADE, the decisional and technical aspects during surgery, and outcomes.

Increasing differential diagnosis between lipoma and liposarcoma through radiomics: a narrative review.

Soft tissue sarcomas (STSs) are rare, heterogeneous, and very often asymptomatic diseases. Their diagnosis is fundamental, as is the identification of the degree of malignancy, which may be high, medium, or low. The Italian Medical Oncology Association and European Society of Medical Oncology (ESMO) guidelines recommend magnetic resonance imaging (MRI) because the clinical examination is typically ineffective. The diagnosis of these rare diseases with artificial intelligence (AI) techniques presents reduced datasets and therefore less robust methods. However, the combination of AI techniques with radiomics may be a new angle in diagnosing rare diseases such as STSs. Results obtained are promising within the literature, not only for the performance but also for the explicability of the data. In fact, one can make tumor classification, site localization, and prediction of the risk of developing metastasis. Thanks to the synergy between computer scientists and radiologists, linking numerical features to radiological evidence with excellent performance could be a new step forward for the diagnosis of rare diseases.

Nonischemic Donor Heart Preservation: New Milestone in Heart Transplantation History.

Heart transplantation is considered the gold standard for the treatment of advanced end-stage heart failure. However, standard donors after brain death are decreasing, whereas patients on the heart transplant waitlist are constantly rising. The introduction of the ex vivo machine perfusion device has been a turning point; in fact, these systems are able to significantly reduce ischemic times and have a potential effect on ischemia-related damage reduction. From a clinical standpoint, these machines show emerging results in terms of heart donor pool expansion, making marginal donors and donor grafts after circulatory death suitable for donation. This article aims to review mechanisms and preclinical and clinical outcomes of currently available ex vivo perfusion systems, and to explore the future fields of application of these technologies.

Endoscopic aortic valve surgery in isolated and concomitant procedures.

OBJECTIVES: To evaluate early outcomes of endoscopic aortic valve replacement (AVR) and risks of concomitant procedures done through the same working port. METHODS: At our institution, we performed a data analysis of 342 consecutive patients (from July 2013 to May 2021) who underwent endoscopic AVR with or without associated major procedure. Preoperative, intraoperative, postoperative data were evaluated. Subsequently, we perform a comparative analysis between the isolated and concomitant surgery group. The surgical access was a 3- to 4-cm working port in the second right intercostal space and 3 additional 5-mm mini-ports for the introduction of the thoracoscope, the transthoracic clamp and the vent line. Cardiopulmonary by-pass was achieved through peripheral cannulation. RESULTS: 105 patients (30.7%) underwent combined procedure: 2 coronary artery bypass (1.9%), 21 ascending aorta replacement (19.6%), 41 mitral surgery (38.3%), 16 mitral and tricuspid surgery (15%) and 25 other procedure (27%). Death occurred in 1 patient (0.4%) in the isolated group versus 2 patients (1.9%) in the combined group (P = 0.175). Seven strokes were observed, 4 in isolated procedures (1.7%) and 3 in the concomitant ones (2.85%) (P = 0.481). Surgical revision for bleeding was performed always through the same access in 13 patients (5.4%) versus 11 patients (10.4%) (P = 0.096). Pacemaker implantation was necessary in 5 patients (2.1%) versus 8 patients (7.6%) (P = 0.014). Median intubation time was 5 (2) h vs 6 (8) (P < 0.080). CONCLUSIONS: Through a single working port made for endoscopic AVR, a concomitant procedure may be done without affecting in-hospital mortality and postoperative stroke rate.

Novel Sources of Biodiversity and Biomolecules from Bacteria Isolated from a High Middle Ages Soil Sample in Palermo (Sicily, Italy).

The urban plan of Palermo (Sicily, Italy) has evolved throughout Punic, Roman, Byzantine, Arab, and Norman ages until it stabilized within the borders that correspond to the current historic center. During the 2012 to 2013 excavation campaign, new remains of the Arab settlement, directly implanted above the structures of the Roman age, were found. The materials investigated in this study derived from the so-called Survey No 3, which consists of a rock cavity of subcylindrical shape covered with calcarenite blocks: it was probably used to dispose of garbage during the Arabic age and its content, derived from daily activities, included grape seeds, scales and bones of fish, small animal bones, and charcoals. Radiocarbon dating confirmed the medieval origin of this site. The composition of the bacterial community was characterized through a culture-dependent and a culture-independent approach. Culturable bacteria were isolated under aerobic and anaerobic conditions and the total bacterial community was characterized through metagenomic sequencing. Bacterial isolates were tested for the production of compounds with antibiotic activity: a Streptomyces strain, whose genome was sequenced, was of particular interest because of its inhibitory activity, which was due to the Type I polyketide aureothin. Moreover, all strains were tested for the production of secreted proteases, with those belonging to the genus Nocardioides having the most active enzymes. Finally, protocols commonly used for ancient DNA studies were applied to evaluate the antiquity of isolated bacterial strains. Altogether these results show how paleomicrobiology might represent an innovative and unexplored source of novel biodiversity and new biotechnological tools. IMPORTANCE One of the goals of paleomicrobiology is the characterization of the microbial community present in archaeological sites. These analyses can usually provide valuable information about past events, such as occurrence of human and animal infectious diseases, ancient human activities, and environmental changes. However, in this work, investigations about the composition of the bacterial community of an ancient soil sample (harvested in Palermo, Italy) were carried out aiming to screen ancient culturable strains with biotechnological potential, such as the ability to produce bioactive molecules and secreted hydrolytic enzymes. Besides showing the biotechnological relevance of paleomicrobiology, this work reports a case of germination of putatively ancient bacterial spores recovered from soil rather than extreme environments. Moreover, in the case of spore-forming species, these results raise questions about the accuracy of techniques usually applied to estimate antiquity of DNA, as they could lead to its underestimation.

Long-Term Outcomes and Risk Factors Analysis for Patients Undergoing Thoracic Endovascular Aorta Repair (TEVAR), According to the Aortic Pathologies.

BACKGROUND: Thoracic endovascular aortic repair (TEVAR) has become a standard treatment for acute and chronic thoracic aorta diseases. We analyzed long-term outcomes and risk factors of TEVAR procedures according to the aortic pathology. METHODS: Demographics, indications, technical details, and outcomes of patients undergoing TEVAR procedures in our institutions were prospectively collected and retrospectively analyzed. Overall survival was determined using Kaplan-Meier methods while log-rank tests were used to compare the survival between groups. Cox regression analysis was used to identify risk factors. RESULTS: Between June 2002 and April 2020, 116 patients underwent TEVAR for different thoracic aorta diseases. Among them, 47 patients (41%) underwent TEVAR for aneurysmatic aortic disease, 26 (22%) for type-B aortic dissection, 23 (20%) for penetrating aortic ulcer, 11 (9%) after previous type-A dissection treatment, and 9 (8%) for traumatic aortic injury. Patients with posttraumatic aortic injury were younger (P < 0.01) with less hypertension (P < 0.01), diabetes (P < 0.01), and prior cardiac surgery (P < 0.01). Survival was different based on indication for TEVAR (log rank 0.024). Patients after previous type-A dissection treatment had the worst survival rate (50% at 5 years) while survival for aneurysmatic aortic disease was 55% at 5 years. No late death occurred in the traumatic group. Cox-regression model identified independent predictors for mortality: age (hazard ratio [HR]: 1.05, 95% confidence interval [CI]: 1.01-1.09, P = 0.006), male gender (HR: 3.2, 95% CI: 1.1-9.2, P = 0.028), moderate chronic obstructive pulmonary disease (HR: 2.1, 95% CI: 1.02-4.55, P = 0.043), previous cardiac surgery (HR: 2.1, 95% CI: 1.008-4.5, P = 0.048), and treatment indication for aneurysm (HR: 2.6, 95% CI: 1.2-5.2, P = 0.008). CONCLUSIONS: TEVAR is a safe and effective procedure with excellent long-term results in case of traumatic aortic injury. The overall long-term survival is affected by aortic pathology, associated comorbidities, gender, and previous cardiac surgery.

Venous External Support in Coronary Artery Bypass Surgery: A Systematic Review and Meta-Analysis.

Neointimal hyperplasia and lumen irregularities are major contributors to vein graft failure and the use of VEST(R) should prevent this. In this review, we aim to evaluate the angiographic outcomes of externally supported vein grafts. Medline, Embase and Cochrane Library were systematically reviewed for randomized clinical trials published by August 2022. The primary outcome was graft failure. Secondary outcomes included graft ectasia, intimal hyperplasia area and thickness, and graft nonuniformity. Odds ratios (OR) for dichotomous variables and mean difference (MD) for continuous variables with 95% confidence intervals (CI) were pooled using a fixed-effects model. Three randomized controlled trials with a total of 437 patients were included with follow-up ranging from 1 to 2 years. The odds of graft failure were similar in the 2 groups (OR 1.22; 95%CI 0.88-1.71; I²â€¯= 0%). Intimal hyperplasia area [MD -0.77 mm2; 95%CI -1.10 to -0.45; I2 = 0%] and thickness [MD -0.06 mm; 95% CI -0.08 to -0.04; I2=0%] were significantly lower in the VEST group. Fitzgibbon Patency Scale of II or III (representing angiographic conduit nonuniformity; OR 0.67; 95%CI 0.48-0.94; I2 = 0%) and graft ectasia (OR 0.53; 95%CI 0.32-0.88; I2 = 33%) were also significantly lower in the VEST group. At short-term follow-up, VEST does not seem to reduce the incidence of graft failure, although it is associated with attenuation of intimal hyperplasia and nonuniformity. Longer angiographic follow-up is warranted to determine whether these positive effects might translate into a positive effect in graft failure and in long-term clinical outcomes.

Totally Endoscopic Constrictive Pericarditis Treatment: A Case Series.

Minimally invasive cardiac surgery has increased in popularity to reduce the morbidity associated with open heart surgery. In this article, a totally endoscopic case series is presented in which anterior pericardiectomy is performed by peripheral femoral arterial and venous cannulation. Right periareoal incision and right submammary incision were used for male and female patients, respectively, to access the heart by the fourth intercostal space.

Percutaneous coronary intervention versus coronary artery bypass graft surgery in dialysis-dependent patients: A pooled meta-analysis of reconstructed time-to-event data.

OBJECTIVE: Το perform a systematic review with meta-analysis of published data comparing outcomes between a percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in dialysis-dependent patients. METHODS: We searched PubMed, Scopus, and Cochrane databases for studies including dialysis-dependent patients who underwent either CABG or PCI. This meta-analysis follows the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We conducted one-stage and two-stage meta-analysis with Kaplan-Meier-derived individual patient data for overall survival and meta-analysis with the random-effects model for the in-hospital mortality and repeat revascularization. RESULTS: Twelve studies met our eligibility criteria, including 13,651 and 28,493 patients were identified in the CABG and PCI arms, respectively. Patients who underwent CABG had overall improved survival compared with those who underwent PCI at the one-stage meta-analysis (hazard ratio [HR]: 1.12, 95% confidence interval [CI]: 1.09-1.16, p < .0001) and the two-stage meta-analysis (HR: 1.15, 95% CI: 1.08-1.23, p < .001, I2 = 30.0%). Landmark analysis suggested that PCI offers better survival before the 8.5 months of follow-up (HR: 0.96, 95% CI: 0.92-0.99, p = .043), while CABG offers an advantage after this timepoint (HR: 1.3, 95% CI: 1.22-1.32, p < .001). CABG was associated with increased odds for in-hospital mortality (odds ratio [OR]: 1.70, 95% CI: 1.50-1.92, p < .001, I2 = 0.0%) and decreased odds for repeat revascularization (OR: 0.22, 95% CI: 0.14-0.34, p < .001, I2 = 58.08%). CONCLUSIONS: In dialysis-dependent patients, CABG was associated with long-term survival but a higher risk for early mortality. The risk for repeat revascularization was higher with PCI.

Gaseous Microemboli in the Cardiopulmonary Bypass Circuit: Presentation of a Systematic Data Collection Protocol Applied at Istituto Cardiocentro Ticino.

Air emboli are reported to enter the cardiovascular system during cardiac surgery despite air-bubble filters in the arterial line of the cardiopulmonary bypass (CPB). A potential association with stroke, covert cerebral insults and cognitive decline after cardiac surgery has been hypothesized. Although most of the previous studies failed to prove it, this hypothesis cannot be rejected because the situation in the operating room (OR) is multifactorial and complex. Therefore, rigorous and standardized protocols are needed to investigate sources, patterns, as well as effective quantity and volume of air embolism.  We hereby present our protocol in detail for systematic data collection as a standard quality control measure at our center, where air bubbles in the cardiopulmonary bypass circuit are measured by a commercial bubble counter. We also show a preview of the type of information that can be obtained for future analysis. The eventual aim is to determine a potential association between air emboli and adverse postoperative outcomes, as well as to identify major sources of air bubbles generation and in the long run to find effective prevention strategies.

Percutaneous coronary intervention versus coronary artery bypass graft for left main coronary artery disease: A meta-analysis.

BACKGROUND: The optimal revascularization strategy for patients with left main coronary artery disease is still controversial. This is systematic review and meta-analysis aims to evaluate the outcomes of percutaneous coronary intervention (PCI) with drug-eluting stents compared with coronary artery bypass graft (CABG) for LM disease. METHODS: Online electronic databases were systematically reviewed until January 2020 for randomized trials comparing PCI with drug-eluting stents and CABG. Primary outcomes were: all-cause mortality, myocardial infarction (MI), stroke, and repeated revascularization. Secondary outcomes included periprocedural and nonperiprocedural MI. The period of follow-up included 30 days, 1 year, and 5 years. Odds ratio and 95% confidence interval were calculated with a fixed-effects model. RESULTS: A total of 4595 patients (5 randomized trials) with left main coronary artery disease were included. At 30 days and 1 year, PCI was associated with lower incidence of stroke, higher repeated revascularization, and similar odds of mortality and MI compared with CABG. At 5 years, PCI was associated with higher rates of MI (odds ratio, 1.43; 95% confidence interval, 1.13-1.79; P = .003) and repeat revascularization (odds ratio, 1.89; 95% CI, 1.58-2.26; P < .001) than CABG. PCI was associated with lower periprocedural MI at 30 days, whereas at 5 years PCI was associated with higher nonperiprocedural MI (odds ratio, 2.32; 95% confidence interval, 1.62-3.31; P < .001). Mortality and stroke rate did not differ at 5-year follow-up. CONCLUSIONS: Patients with left main coronary artery disease treated with either PCI or CABG do not show significant difference in early or 5-year mortality. Although CABG was associated with higher stroke rates at 30 days and 1 year, PCI was associated with an increase in MI and need for repeat revascularization at 5 years.

Transcatheter aortic valve replacement for structural degeneration of previously implanted transcatheter valves (TAVR-in-TAVR): a systematic review.

OBJECTIVES: Transcatheter aortic valve replacement (TAVR) represents a valid treatment for patients with aortic valve stenosis and high or intermediate surgical risk. However, biological transcatheter valves can also experience a structural degeneration after years, and a redo-TAVR procedure (TAVR-in-TAVR) can be a valid option. We revised the current available literature for indications, procedural and technical details and outcome on TAVR-in-TAVR procedures for degenerated TAVR valves. METHODS: A systematic search was conducted in the public medical database for scientific articles on TAVR-in-TAVR procedures for degenerated transcatheter valves. Data on demographics, indications, first and second transcatheter valve type and size, mortality, complications and follow-up were extracted and analysed. RESULTS: A total of 13 studies (1 multicentre, 3 case series, 9 case reports) were included in this review, with a total amount of 160 patients treated with TAVR-in-TAVR procedures for transcatheter valve failure. The mean age was 74.8 ± 7.8 with 84 males (52.8%). The mean elapsed time from the first TAVR procedure was 58.1 ± 23.4 months. Main indication for TAVR-in-TAVR was pure stenosis (38.4%, with mean gradient of 44.5 ± 18.5 mmHg), regurgitation (31.4%), mixed stenosis and regurgitation (29.5%) and leaflet thrombosis (8.8%). Procedural success rate was 86.8%, with second TAVR valve malposition occurred in 4 cases (2.5%). The hospital mortality rate was 1.25% (2/160). Post-procedural echocardiographic control showed moderate regurgitation in 5.6% of patients (9/160) and residual transvalvular mean gradient ≥20 mmHg in 5% of cases. Postoperative complications included major vascular complications (8.7%), new pacemaker implantation (8.7%), acute kidney failure (3.7%), stroke (0.6%) and coronary obstruction (0.6%). The mean follow-up time was 6 ± 5.6 months with 1 non-cardiovascular death reported. CONCLUSIONS: TAVR-in-TAVR represents a valid alternative to standard surgery for the treatment of degenerated transcatheter valves in high-risk patients. Despite these promising results, further studies are required to assess durability and haemodynamic performances of the second TAVR valve.

Lysosome purinergic receptor P2X4 regulates neoangiogenesis induced by microvesicles from sarcoma patients.

The tumor microenvironment modulates cancer growth. Extracellular vesicles (EVs) have been identified as key mediators of intercellular communication, but their role in tumor growth is largely unexplored. Here, we demonstrate that EVs from sarcoma patients promote neoangiogenesis via a purinergic X receptor 4 (P2XR4) -dependent mechanism in vitro and in vivo. Using a proteomic approach, we analyzed the protein content of plasma EVs and identified critical activated pathways in human umbilical vein endothelial cells (HUVECs) and human progenitor hematopoietic cells (CD34+). We then showed that vessel formation was due to rapid mitochondrial activation, intracellular Ca2+ mobilization, increased extracellular ATP, and trafficking of the lysosomal P2XR4 to the cell membrane, which is required for cell motility and formation of stable branching vascular networks. Cell membrane translocation of P2XR4 was induced by proteins and chemokines contained in EVs (e.g. Del-1 and SDF-1). Del-1 was found expressed in many EVs from sarcoma tumors and several tumor types. P2XR4 blockade reduced EVs-induced vessels in angioreactors, as well as intratumor vascularization in mouse xenografts. Together, these findings identify P2XR4 as a key mediator of EVs-induced tumor angiogenesis via a signaling mediated by mitochondria-lysosome-sensing response in endothelial cells, and indicate a novel target for therapeutic interventions.