Incidence and outcomes of prosthetic valve thrombosis during peripheral extracorporeal membrane oxygenation.

OBJECTIVES: In the context of postcardiotomy cardiogenic shock (PCCS) following valve replacement surgery, it may be necessary to implant a peripheral veno-arterial extracorporeal membrane oxygenation (pVA-ECMO). This procedure, however, carries a risk of prosthetic valve thrombosis. The aim of this retrospective study was to describe the incidence and outcomes of prosthetic valve thrombosis after VA-ECMO support for PCCS and to report the associated risk factors. METHODS: All consecutive adult patients who received pVA-ECMO for PCCS following a valve replacement procedure between January 2015 and October 2019 in our institution were included in this retrospective study. Outcome variables were prosthetic valve thrombosis, 30-day and hospital survival, pVA-ECMO-associated adverse events and surgery-related adverse events. RESULTS: During the 4-year study period, 549 patients received pVA-ECMO for PCCS. Among them, 152 had undergone a valve replacement procedure and 9 of these developed prosthetic valve thrombosis. The incidence of valve thrombosis at 30 days was 7.5 ± 2%. The cumulative Incidence of prosthetic valve thrombosis was significantly lower with pVA-ECMO + IABP versus VA-ECMO alone (1.4 ± 1.4% vs 13.7 ± 4.7%, p = 0.021, respectively). Intra-aortic balloon pump use associated with pVA-ECMO (versus pVA-ECMO alone) was an independent protective factor against hospital death (OR = 0.180 [0.068-0.478], p = 0.001). CONCLUSIONS: After PCCS following valve replacement surgery, peripheral femoro-femoral VA-ECMO is associated with a low risk of acute valve thrombosis especially when associated with an IABP.

Treatment time limit for successful weaning from veno-arterial extracorporeal membrane oxygenation in cardiogenic shock.

AIMS: Knowing the upper time limit for successful weaning from temporary mechanical circulatory support in cardiogenic shock will help with decision-making regarding advanced heart failure (HF) therapy or considering withdrawal of care. The aim of this study was to investigate the association between the support duration and successful weaning from veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in patients with cardiogenic shock. METHODS AND RESULTS: A retrospective single-centre cohort study was conducted between January 2013 and June 2023. It included 100 consecutive patients with cardiogenic shock who were treated with VA-ECMO. Patients with out-of-hospital cardiac arrest were excluded. The primary outcome was successful weaning from VA-ECMO (i.e., VA-ECMO decannulation and survival to discharge). The association between the length of support duration and the weaning success rate was analysed. Patients were divided into three groups according to ECMO support duration: Group A (≤7 days), Group B (8-14 days), and Group C (≥15 days). Multivariable logistic regression analysis was used to evaluate the impact of the length of support duration on successful weaning of VA-ECMO. The median age was 67 years, and 73% of study participants were male. The underlying aetiologies of cardiogenic shock were as follows: acute myocardial infarction, 50; fulminant myocarditis, 19; cardiomyopathy, 15; valvular heart disease, 8; and other, 8. Seventy-five patients (75%) were attempted to wean VA-ECMO, and 67 moved on to decannulation. In total, 43 (43%) patients were successfully weaned from VA-ECMO. The median length of ECMO support duration was 8 [3-15] days. Compared with those who underwent successful ECMO decannulation, those who did not had a significantly longer support duration of VA-ECMO (5 [3-9] days vs. 12 [3-22] days, P = 0.004). The weaning success rate was significantly higher in patients with short support duration; 58% (29/50), 40% (10/25), 16% (4/25) in Groups A, B, and C, respectively (P = 0.002). Overall, none of the patients supported for over 24 days (0/11) were successfully weaned from VA-ECMO. On multivariable logistic regression analysis, the length of support duration was independently associated with successful weaning after adjusting for age, sex, underlying aetiology, and left ventricular ejection fraction (odds ratio, 0.813 [per 3 days]; 95% confidence interval, 0.679-0.914; P = 0.025). CONCLUSIONS: Long support duration of VA-ECMO was significantly associated with a low rate of successful weaning in patients with cardiogenic shock. Patients who require VA-ECMO for over 1 week should start considering advanced HF therapy or withdrawal of care.

Predictors of membrane oxygenator failure in pediatric extracorporeal membrane oxygenation.

BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is increasingly utilized in pediatric patients. Failure to recognize membrane oxygenator failure can lead to critical complications due to rapid deterioration of membrane oxygenator function. Therefore, identifying the predictors for membrane oxygenator exchange is crucial. However, risk factors for membrane oxygenator exchange in pediatric V-A ECMO remain unclear; therefore, this study aimed to evaluate these risk factors. METHODS: This retrospective cohort study enrolled all pediatric patients aged <18 years who received V-A ECMO between August 2018 and July 2023 at a tertiary-care pediatric hospital in Japan. The Cox proportional hazards model was used to evaluate the predictors of membrane oxygenator failure within 72 h after initiation. RESULTS: During the study period, membrane oxygenator failure occurred in 18/55 (32.7%) children within 72 h; membrane oxygenator failure within 72 h occurred in 4/29 (13.8%) and 14/26 (53.8%) in the groups with ratio of blood flow divided by the blood flow limit of the membrane oxygenator (B/L) of <0.5 and ≥0.5, respectively (adjusted hazards ratio, 4.97 [95% confidence interval, 1.33-18.5]; p = 0.017). After adjusting for delta pressure of the oxygenator, an increase in body weight and aspartate aminotransferase levels were associated with an increase in early membrane oxygenator failure. CONCLUSIONS: This retrospective study demonstrated that a B/L ratio >0.5, an increase in body weight, and elevated aspartate aminotransferase were independent risk factors for early membrane oxygenator failure in pediatric V-A ECMO. However, a prospective multicenter study with an appropriate sample size is warranted to mitigate potential bias, and enhance generalizability for further investigation of the association between a B/L ratio and early membrane oxygenator failure.

Veno-arterial extracorporeal membrane oxygenation for the treatment of obstructive shock caused by venous air embolism: A case report.

BACKGROUND: Venous air embolism (VAE) is a potentially lethal condition, with a reported incidence rate of about 0.13%, and the true incidence may be higher since many VAE are asymptomatic. The current treatments for VAE include Durant's maneuver, aspiration and removal of air through venous catheters, and hyperbaric oxygen therapy. For critically ill patients, use of cardiotonic drugs and chest compressions remain useful strategies. The wider availability of extracorporeal membrane oxygenation (ECMO) has brought a new option for VAE patients. CASE SUMMARY: A 53-year-old female patient with VAE presented to the emergency clinic due to abdominal pain with fever for 1 d and unconsciousness for 2 h. One day ago, the patient suffered from abdominal pain, fever, and diarrhea. She suddenly became unconscious after going to the toilet during the intravenous infusion of ciprofloxacin 2 h ago, accompanied by nausea and vomiting, during which a small amount of gastric contents were discharged. She was immediately sent to a local hospital, where cranial and chest computed tomography showed bilateral pneumonia as well as accumulated air visible in the right ventricle and pulmonary artery. The condition deteriorated despite endotracheal intubation, rehydration, and other treatments, and the patient was then transferred to our hospital. Veno-arterial ECMO was applied in our hospital, and the patient's condition gradually improved. The patient was successfully weaned from ECMO and extubated after two days. CONCLUSION: ECMO may be an important treatment for patients with VAE in critical condition.

Science of left ventricular unloading.

The concept of left ventricular unloading has its foundation in heart physiology. In fact, the left ventricular mechanics and energetics represent the cornerstone of this approach. The novel sophisticated therapies for acute heart failure, particularly mechanical circulatory supports, strongly impact on the mechanical functioning and energy consuption of the heart, ultimately affecting left ventricle loading. Notably, extracorporeal circulatory life support which is implemented for life-threatening conditions, may even overload the left heart, requiring additional unloading strategies. As a consequence, the understanding of ventricular overload, and the associated potential unloading strategies, founds its utility in several aspects of day-by-day clinical practice. Emerging clinical and pre-clinical research on left ventricular unloading and its benefits in heart failure and recovery has been conducted, providing meaningful insights for therapeutical interventions. Here, we review the current knowledge on left ventricular unloading, from physiology and molecular biology to its application in heart failure and recovery.

Treatment of a patient with aconitine poisoning using veno-arterial membrane oxygenation: A case report.

BACKGROUND: Aconitine poisoning is highly prone to causing malignant arrhythmias. The elimination of aconitine from the body takes a considerable amount of time, and during this period, patients are at a significant risk of death due to malignant arrhythmias associated with aconitine poisoning. CASE SUMMARY: A 30-year-old male patient was admitted due to accidental ingestion of aconitine-containing drugs. Upon arrival at the emergency department, the patient intermittently experienced malignant arrhythmias including ventricular tachycardia, ventricular fibrillation, ventricular premature beats, and cardiac arrest. Emergency interventions such as cardiopulmonary resuscitation and defibrillation were promptly administered. Additionally, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) therapy was initiated. Successful resuscitation was achieved before ECMO placement, but upon initiation of ECMO, the patient experienced recurrent malignant arrhythmias. ECMO was utilized to maintain hemodynamics and respiration, while continuous blood purification therapy for toxin clearance, mechanical ventilation, and hypothermic brain protection therapy were concurrently administered. On the third day of VA-ECMO support, the patient's respiratory and hemodynamic status stabilized, with only frequent ventricular premature beats observed on electrocardiographic monitoring, and echocardiography indicated recovery of cardiac contractile function. On the fourth day, a significant reduction in toxin levels was observed, along with stable hemodynamic and respiratory functions. Following a successful pump-controlled retrograde trial occlusion test, ECMO assistance was terminated. The patient gradually improved postoperatively and achieved recovery. He was discharged 11 days later. CONCLUSION: VA-ECMO can serve as a bridging resuscitation technique for patients with reversible malignant arrhythmias.

Successful prehospital ECMO in drowning resuscitation after prolonged submersion.

An 18-year-old drowning victim was successfully resuscitated using prehospital veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Despite 24 min of submersion in water with a surface temperature of 15 °C, the patient was cannulated on-scene and transported to a trauma center. After ICU admission on VA-ECMO, he was decannulated and extubated by day 5. He was transferred to a peripheral hospital on day 6 and discharged home after 3.5 weeks with favorable neurological outcome of a Cerebral Performance Categories (CPC) score of 1 out of 5. This case underscores the potential of prehospital ECMO in drowning cases within a well-equipped emergency response system.

Retrograde Aortic Valve Migration During Transcatheter Aortic Valve Replacement for Aortic Regurgitation: A Case Report Highlighting the Importance of Prompt Venoarterial Extracorporeal Membrane Oxygenation (VA-ECMO) Initiation.

Surgical aortic valve replacement (SAVR) is the recommended curative treatment for pure native aortic regurgitation (AR). However, some patients are not suitable for SAVR due to comorbidities or frailty. Transcatheter aortic valve replacement (TAVR) has been reported to offer a better prognosis than medical therapy in AR patients; thus, the use of TAVR for AR may increase in the future. However, the reduced calcification and annulus ring stiffness associated with TAVR may increase the risk of valve migration. Accumulating data on rescue measures in the event of valve migration is necessary. An 87-year-old female with a history of hypertension and persistent atrial fibrillation presented to our emergency department with dyspnea. The patient was diagnosed with congestive heart failure class IV, according to the New York Heart Association classification, necessitating urgent admission to our cardiac department. Due to the patient's high surgical risk (Society of Thoracic Surgeons (STS) score 9.17%, Euro2 score 9.55%, frailty 6), the heart team performed TAVR with a right femoral arterial approach. The patient was sedated, and pacing was initiated at 180 bpm. We placed an Edwards SAPIEN 3 valve (Edwards Lifesciences, Irvine, CA, USA) #23 (-1 mL volume, with attached balloon). During the post-deployment procedure, the aortic valve migrated retrogradely into the left ventricle (LV). Despite the occurrence of severe aortic valve regurgitation, the patient's vital signs remained stable. Five minutes after the migration of the aortic valve, venoarterial extracorporeal membrane oxygenation (VA-ECMO) was initiated. A second TAVR valve implantation was then performed. However, after the second valve implantation and the removal of the pre-shaped guidewire (Safari2 pre-shaped guidewire extra small, Boston Scientific, Marlborough, MA, USA), the migrated valve became stuck in the left ventricular outflow tract (LVOT) in a reverse position, resulting in severely limited left ventricular ejection. We increased the support provided by VA-ECMO, and surgical conversion to SAVR was performed without experiencing circulatory collapse. Surgical aortic valve replacement was initiated successfully, and withdrawal of the cardiopulmonary bypass (CPB) was performed without complications. The patient was extubated on the first postoperative day (POD), discharged from the ICU on POD 3, and transferred for rehabilitation on POD 27. In summary, the prompt introduction of VA-ECMO was important for avoiding complications and saving the patient's life following the retrograde migration of the TAVR valve.

Extracorporeal Life Support in Myocardial Infarction: New Highlights.

Background and Objectives: Cardiogenic shock (CS) is a potentially severe complication following acute myocardial infarction (AMI). The use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in these patients has risen significantly over the past two decades, especially when conventional treatments fail. Our aim is to provide an overview of the role of VA-ECMO in CS complicating AMI, with the most recent literature highlights. Materials and Methods: We have reviewed the current VA-ECMO practices with a particular focus on CS complicating AMI. The largest studies reporting the most significant results, i.e., overall clinical outcomes and management of the weaning process, were identified in the PubMed database from 2019 to 2024. Results: The literature about the use of VA-ECMO in CS complicating AMI primarily has consisted of observational studies until 2019, generating the need for randomized controlled trials. The EURO-SHOCK trial showed a lower 30-day all-cause mortality rate in patients receiving VA-ECMO compared to those receiving standard therapy. The ECMO-CS trial compared immediate VA-ECMO implementation with early conservative therapy, with a similar mortality rate between the two groups. The ECLS-SHOCK trial, the largest randomized controlled trial in this field, found no significant difference in mortality at 30 days between the ECMO group and the control group. Recent studies suggest the potential benefits of combining left ventricular unloading devices with VA-ECMO, but they also highlight the increased complication rate, such as bleeding and vascular issues. The routine use of VA-ECMO in AMI complicated by CS cannot be universally supported due to limited evidence and associated risks. Ongoing trials like the Danger Shock, Anchor, and Recover IV trials aim to provide further insights into the management of AMI complicated by CS. Conclusions: Standardizing the timing and indications for initiating mechanical circulatory support (MCS) is crucial and should guide future trials. Multidisciplinary approaches tailored to individual patient needs are essential to minimize complications from unnecessary MCS device initiation.

Mitral bioprosthesis early dysfunction treated with transapical valvuloplasty during V-A ECMO.

We report the case of a 61-year-old male who had complications with a mitral valve (MV) bioprosthesis replacement by post-cardiotomy shock leading to VA ECMO implantation. The patient suffered early bioprosthetic valve failure owing to early thrombosis. The complication was successfully treated with a MV bioprosthesis transapical balloon valvuloplasty that restored normal leaflet mobility.

Prevalence and risk factors for in-hospital mortality of adult patients on veno-arterial extracorporeal membrane oxygenation for cardiogenic shock and cardiac arrest: A systematic review and meta-analysis.

OBJECTIVES: To synthesize quantitative research findings on the prevalence and risk factors for in-hospital mortality of patients on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). METHODS: A comprehensive search was conducted for the period from May 2008 to December 2023 by searching the five electronic databases of PubMed, CINAHL, Web of Science, EMBASE, and Cochrane library. The quality of included studies was assessed using the Newcastle-Ottawa scale. The meta-analysis estimated the pooled odds ratio or standard mean difference and 95% confidence intervals. RESULTS: A total of twenty-five studies with 10,409 patients were included in the analysis. The overall in-hospital mortality of patients on VA-ECMO was 56.7 %. In the subgroup analysis, in-hospital mortality of VA-ECMO for cardiogenic shock and cardiac arrest was 49.2 % and 75.2 %, respectively. The number of significant factors associated with an increased risk of in-hospital mortality in the pre-ECMO period (age, body weight, creatinine, chronic kidney disease, pH, and lactic acid) was greater than that in the intra- and post-ECMO periods. Renal replacement, bleeding, and lower limb ischemia were the most significant risk factors for in-hospital mortality in patients receiving VA-ECMO. CONCLUSION: Early detection of the identified risk factors can contribute to reducing in-hospital mortality in patients on VA-ECMO. Intensive care unit nurses should provide timely and appropriate care before, during, and after VA-ECMO. IMPLICATIONS FOR CLINICAL PRACTICE: Intensive care unit nurses should be knowledgeable about factors associated with the in-hospital mortality of patients on VA-ECMO to improve outcomes. The present findings may contribute to developing guidelines for reducing in-hospital mortality among patients considering ECMO.

Hemodynamics with mechanical circulatory support devices using a cardiogenic shock model.

Mechanical circulatory support (MCS) devices, including veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and Impella, have been widely used for patients with cardiogenic shock (CS). However, hemodynamics with each device and combination therapy is not thoroughly understood. We aimed to elucidate the hemodynamics with MCS using a pulsatile flow model. Hemodynamics with Impella CP, VA-ECMO, and a combination of Impella CP and VA-ECMO were assessed based on the pressure and flow under support with each device and the pressure-volume loop of the ventricle model. The Impella CP device with CS status resulted in an increase in aortic pressure and a decrease in end-diastolic volume and end-diastolic pressure (EDP). VA-ECMO support resulted in increased afterload, leading to a significant increase in aortic pressure with an increase in end-systolic volume and EDP and decreasing venous reservoir pressure. The combination of Impella CP and VA-ECMO led to left ventricular unloading, regardless of increase in afterload. Hemodynamic support with Impella and VA-ECMO should be a promising combination for patients with severe CS.

Left Ventricular Unloading in Extracorporeal Membrane Oxygenation: A Clinical Perspective Derived from Basic Cardiovascular Physiology.

PURPOSE OF REVIEW: To present an abridged overview of the literature and pathophysiological background of adjunct interventional left ventricular unloading strategies during veno-arterial extracorporeal membrane oxygenation (V-A ECMO). From a clinical perspective, the mechanistic complexity of such combined mechanical circulatory support often requires in-depth physiological reasoning at the bedside, which remains a cornerstone of daily practice for optimal patient-specific V-A ECMO care. RECENT FINDINGS: Recent conventional clinical trials have not convincingly shown the superiority of V-A ECMO in acute myocardial infarction complicated by cardiogenic shock as compared with medical therapy alone. Though, it has repeatedly been reported that the addition of interventional left ventricular unloading to V-A ECMO may improve clinical outcome. Novel approaches such as registry-based adaptive platform trials and computational physiological modeling are now introduced to inform clinicians by aiming to better account for patient-specific variation and complexity inherent to V-A ECMO and have raised a widespread interest. To provide modern high-quality V-A ECMO care, it remains essential to understand the patient's pathophysiology and the intricate interaction of an individual patient with extracorporeal circulatory support devices. Innovative clinical trial design and computational modeling approaches carry great potential towards advanced clinical decision support in ECMO and related critical care.

Prevalence and prognostic relevance of invasive fungal disease during veno-arterial ECMO: A retrospective single-center study.

PURPOSE: To assess the prevalence and relevance of invasive fungal disease (IFD) during veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO). METHODS: Retrospective analysis from January 2013 to November 2023 of adult V-A ECMO cases at a German University Hospital. Parameters relating to IFD, demographics, length of stay (LoS), days on ECMO and mechanical ventilation, prognostic scores and survival were assessed. Multivariable logistic regression analyses with IFD and death as dependent variables were performed. Outcome was assessed after propensity score matching IFD-patients to non-IFD-controls. RESULTS: 421 patients received V-A ECMO. 392 patients with full electronic datasets were included. The prevalence of IFD, invasive candidiasis and probable invasive pulmonary aspergillosis was 4.6%, 3.8% and 1.0%. Severity of acute disease, pre-existing moderate-to-severe renal disease and continuous kidney replacement therapy were predictive of IFD. In-hospital mortality (94% (17/18) compared to 67% (252/374) in non-IFD patients (p = 0.0156)) was predicted by female sex, SOFA score at admission, SAVE score and IFD (for IFD: OR: 8.31; CI: 1.60-153.18; p: 0.044). There was no difference in outcome after matching IFD-cases to non-IFD-controls. CONCLUSIONS: IFD are detected in about one in 20 patients on V-A ECMO, indicating mortality >90%. However, IFD do not contribute to prognosis in this population.

Intraoperative Catastrophic Acute Pulmonary Embolism: A Case Report.

This case report describes a 75-year-old female with a medical history including recurrent bowel obstruction due to sigmoid stricture, atrial fibrillation managed with rivaroxaban, a 50-year one pack-per-day smoking history, hypertension, hyperlipidemia, peripheral vascular disease with bilateral iliac stents (2015), stage III chronic kidney disease, and renal artery stenosis with bilateral stenting. She was transferred from outside hospital for an elective sigmoidectomy with ileorectal anastomosis following several recent admissions due to bowel obstruction that had been managed non-operatively. She was deemed optimized for surgery by the primary care team; however, during induction, she developed pulseless ventricular tachycardia requiring extensive resuscitative efforts. Intraoperative findings revealed biventricular failure and a clot in the right pulmonary artery. Despite aggressive treatment, including veno-arterial extracorporeal membrane oxygenation (VA ECMO), the patient's condition deteriorated, and life support was ultimately withdrawn. This case highlights the challenges of managing complex surgical patients and underscores the importance of multidisciplinary care in such cases.

Invisible Active Bleeding Due to the Watershed Phenomenon.

A case is presented of an 83-year-old female patient with a strong suspicion of active bleeding, but no diagnostic contrast blush could be seen on the original computed tomography (CT) scan. Teaching point: When performing CT angiography in veno-arterial extracorporeal membrane oxygenation (VA-ECMO), it is important to understand the altered haemodynamics, as flow-related artefacts such as the vascular watershed phenomenon can obscure bleeding.

Cardiac Extracorporeal Membrane Oxygenation in Community Cardiac Surgery Program: Are the Results Comparable?

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) outcomes in small centers are commonly considered less favorable than in large-volume centers. New ECMO protocols and procedures were established in our regional community hospital system as part of a cardiogenic shock initiative. This retrospective study aims to evaluate the outcomes of veno-arterial extracorporeal membrane oxygenation (VA ECMO) and extracorporeal cardiopulmonary resuscitation (ECPR) in a community hospital system with cardiac surgery capability and assess whether protocol optimization and cannulation standards result in comparable outcomes to larger centers whether the outcomes of this new ECMO program at the community hospital setting were comparable to the United States averages. METHODS: Our regional system comprises five hospitals with 1500 beds covering southwestern New Jersey, with only one of these hospitals having cardiac surgery and ECMO capability. In May 2021, the new ECMO program was initiated. Patients were screened by a multidisciplinary call, cannulated by our ECMO team, and subsequently treated by the designated team. We reviewed our cardiac ECMO outcomes over two years, from May 2021 to April 2023, in patients who required ECMO due to cardiogenic shock or as a part of extracorporeal cardiopulmonary resuscitation (ECPR). RESULTS: A total of 60 patients underwent cardiac ECMO, and all were VA ECMO, including 18 (30%) patients who required ECPR for cardiac arrest. The overall survival rate for our cardiac ECMO program turned out to be 48% (29/60), with 50% (22/42) in VA ECMO excluding ECPR and 39% (7/18) in the ECPR group. The hospital survival rate for the VA ECMO and ECPR groups was 36% (15/42) and 28% (5/18), respectively. The ELSO-reported national average for hospital survival is 48% for VA ECMO and 30% for ECPR. Considering these benchmarks, the hospital survival rate of our program did not significantly lag behind the national average. CONCLUSIONS: With protocol, cannulation standards, and ECMO management optimized, the VA ECMO results of a community hospital system with cardiac surgery capability were not inferior to those of larger centers.

Effect of veno-arterial extracorporeal membrane oxygenation lower-extremity cannulation on intra-arterial flow characteristics, oxygen content, and thrombosis risk.

PURPOSE: This study aimed to investigate the effects of lower-extremity cannulation on the intra-arterial hemodynamic environment, oxygen content, blood damage, and thrombosis risk under different levels of veno-arterial (V-A) ECMO support. METHODS: Computational fluid dynamics methods were used to investigate the effects of different levels of ECMO support (ECMO flow ratios supplying oxygen-rich blood 100-40 %). Flow rates and oxygen content in each arterial branch were used to determine organ perfusion. A new thrombosis model considering platelet activation and deposition was proposed to determine the platelet activation and thrombosis risk at different levels of ECMO support. A red blood cell damage model was used to explore the risk of hemolysis. RESULTS: Our study found that partial recovery of cardiac function improved the intra-arterial hemodynamic environment, with reduced impingement of the intra-arterial flow field by high-velocity blood flow from the cannula, a flow rate per unit time into each arterial branch closer to physiological levels, and improved perfusion in the lower extremities. Partial recovery of cardiac function helps reduce intra-arterial high shear stress and residence time, thereby reducing blood damage. The overall level of hemolysis and platelet activation in the aorta decreased with the gradual recovery of cardiac contraction function. The areas at high risk of thrombosis under V-A ECMO femoral cannulation support were the aortic root and the area distal to the cannula, which moved to the descending aorta when cardiac function recovered to 40-60 %. However, with the recovery of cardiac contraction function, hypoxic blood pumped by the heart is insufficient in supplying oxygen to the front of the aortic arch, which may result in upper extremity hypoxia. CONCLUSION: We developed a thrombosis risk prediction model applicable to ECMO cannulation and validated the model accuracy using clinical data. Partial recovery of cardiac function contributed to an improvement in the aortic hemodynamic environment and a reduction in the risk of blood damage; however, there is a potential risk of insufficient perfusion of oxygen-rich blood to organs.

Application of extracorporeal membrane oxygenation in the remote transport of a patient with a ruptured sinus of Valsalva aneurysm: a case report.

Background: A ruptured sinus of Valsalva aneurysm can lead to rapid heart failure and sudden cardiac death. Management of patients who develop severe heart failure and need to be transferred to a specialized hospital for surgical treatment can be challenging. In patients with severe shock due to a ruptured sinus of Valsalva aneurysm into the right atrium, extracorporeal membrane oxygenation (ECMO) transport is an effective means to ensure patient safety, but increases the right cardiac load. We report the experience of veno-arterial (VA) ECMO transport in the treatment of acute cardiogenic shock caused by rupture of a congenital sinus of Valsalva aneurysm. Case presentation: We describe the case of an 18-year-old male who began having acute episodes of chest pain, shortness of breath, palpitations, and dizziness 18 h before presenting to the emergency department. An echocardiogram revealed an acute ruptured sinus of Valsalva aneurysm and a shunt to the right atrium. The patient presented with severe shock. VA-ECMO was administered to ensure safe transport to the cardiac center. The outcome of emergency surgical repair was good. The patient was on ECMO for 8 h. He returned to the general ward after 7 days and was successfully discharged after 40 days. He had good exercise tolerance 2 years after surgery and no evidence of heart failure. Conclusion: Although ECMO transport can increase right cardiac load, it is an effective and safe method to move patients with severe shock caused by a ruptured sinus of Valsalva aneurysm into the right atrium. Methods to decrease right cardiac load, such as decreasing ECMO flow combined with cardiotonic drugs, should be adopted. Successful treatment involves rapid establishment of cardiopulmonary bypass and urgent repair of the ruptured sinus of Valsalva aneurysm.