ELSO Interim Guidelines for Venoarterial Extracorporeal Membrane Oxygenation in Adult Cardiac Patients

Over the past decade, the use of extracorporeal membrane oxygenation (ECMO) has increased exponentially, from approximately 30–40 patients per year in the United States 20 years ago, to over 2,000 per year currently, and rising.1 The increased utilization of ECMO has resulted from improved cannulation techniques, including percutaneous approach, as well as advances in the technology of the pumps, oxygenators, and cannulas. Despite these features, however, choosing appropriate candidates and managing their daily care can be extremely challenging. What follows is an in-depth discussion of the indications for venoarterial (VA) ECMO in adult patients affected by cardiac disease, the manner of its application, the physiology underlying the care for these patients, and the assessment and treatment of complications, including ethical and organizational issues. More in-depth material and information are provided in the Extracorporeal Life Support Organization (ELSO) 5th Edition Red Book.2 Furthermore, the recent ELSO indications about ECLS and cannulation nomenclature will be followed in this guideline.3,4 Decision Making in Adult VA ECMO for Acute Cardiac Failure VA ECMO may support patients for days or weeks as a “bridge-to-decision” that includes weaning after recovery of cardiac function, transplantation, long-term mechanical circulatory support (MCS), and withdrawal in the case of futility. Dedicated documents for the use of VA ECMO in the setting of cardiac arrest and postcardiotomy in adult patients are addressed by additional ELSO guidelines and as joint society position paper (expert consensus of EACTS/ELSO/STS/AATS).5 Indications Specific physiologic goals, monitoring, and patient selection. Cardiogenic shock suitable for ECMO is generally characterized by systemic systolic pressure less than 90, urine output < 30 ml/hour, lactate over 2, SVO2 less than 60%, altered conscious state for 6 hours unresponsive to optimal treatment (Table 1). The goal is to maintain systemic oxygen delivery at least 3 times oxygen consumption (the DO2:VO2 ratio is >3) (normal is 5, shock is 2): O2 delivery is arterial oxygen content (normal 20 ml/dl) times cardiac output (normal 30 dl/m2/min). In VA ECMO access, addressing the goal is easy because the cardiac output is the ECMO flow and the arterial hemoglobin saturation is 100%, so content is easily calculated, knowing the hemoglobin concentration (normal 15 g/dl). In VA ECMO, the drainage blood saturation (the SVO2) measures the DO2:VO2 ratio, and SVO2 is measured continuously. If the arterial saturation is 100% and the venous sat is 80%, the ratio is 5:1. So, adjusting flow and hemoglobin to maintain SVO2 over 66% assures that the goal of DO2/VO2 > 3 is met. Additional details are described in the Red Book chapter on physiology.2 Table 1. - Clinical Features of Cardiogenic Shock and Defined Contemporary Trials and Guidelines Clinical Trial/Guidelines Cardiogenic Shock Criteria SHOCK Trial (1999) • SBP < 90 mm Hg or vasopressor support to maintain SBP >90 mm Hg• Evidence of end-organ damage (UO < 30 ml/h or cool extremities)• Hemodynamic criteria: CI < 2.2 and PCWP > 15 mm Hg IABP-SOAP II (2012) • MAP < 70 mm Hg or SBP < 100 mm Hg despite adequate fluid resuscitation (at least 1 L of crystalloid or 500 ml of colloids)• Evidence of end-organ damage (AMS, mottled skin, UO < 0.5 ml/kg/h for 1 h or serum lactate >2 mmol/L) EHS-PCI (2012) • SBP < 90 mm Hg for 30 min or inotropes use to maintain SBP >90 mm Hg• Evidence of end-organ damage and increased filling pressure ESC-HF Guidelines (2016) • SBP < 90 mm Hg with appropriate fluid resuscitation with clinical and laboratory evidence of end-organ damage• Clinical: cold extremities, oliguria, AMS, narrow pulse pressure. Laboratory: metabolic acidosis, elevated serum lactate, elevated serum creatinine KAMIR-NIH (2018) • SBP < 90 mm Hg for >30 min or supportive intervention to maintain SBP >90 mm Hg• Evidence of end-organ damage (AMS, UO < 30 ml/h, or cool extremities) AMS, altered mental status; CI, cardiac index; EHS-PCI, Euro-Heart Survey Percutaneous Coronary Intervention Registry; ESC-HF, European Society of Cardiology—Heart Failure; IABP-SOAP II, Intra-aortic balloon pump in cardiogenic shock II; KAMIR-NIH, Korean Acute Myocardial Infarction Registry—National Institute of Health; MAP, mean arterial pressure; PCWP, pulmonary capillary wedge pressure; SBP, systolic blood pressure; SHOCK, Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock; UO, Urine output. Short-term MCS should be considered in patients with refractory cardiogenic shock with a potentially reversible or surgically correctable cause.6 Compared with other percutaneous temporary MCS, VA ECMO has advantages for patients with severe biventricular failure or in case of malignant arrhythmia as well as associated pulmonary failure. The classical scenario where VA ECMO should be considered occurs when medical treatment, including fluids, inotropes, and, potentially, intra-aortic balloon pump (IABP), fails. Ideally, VA ECMO should be initiated before multiorgan failure and after thorough echocardiography evaluation. The patient’s age, comorbidities, and prognosis of the underlying illness should also be factored into the ECMO decision making. Age per se’, however, should not be considered an absolute contraindication, especially when greater prospects of cardiac recovery exist, given that the suitability for bridging durable MCS and heart transplantation may diminish with advancing age. Common situations for ECMO are patients with medical (acute myocardial infarction, fulminant myocarditis, intoxication with cardiotoxic drugs, end-stage dilated or ischemic cardiomyopathy, hypothermia with refractory cardiocirculatory instability, and massive pulmonary embolism), and postsurgical (including posttransplantation) acute cardiogenic shock. Other emerging indications for VA ECMO are shown in Figure 1.Figure 1.: Common (dark gray) and emerging situations (light gray) for venoarterial extracorporeal life support in the context of cardiogenic shock. AMI, acute myocardial infarction; APE, massive pulmonary embolism; LVAD, left ventricular assist device; Sepsis, sepsis-associated cardiomyopathy.Contraindications Regarding the contraindications for VA ECMO implant, these are listed below: - • Cardiac recovery unlikely and no indication for heart transplant or durable left ventricular (LV) assists device • Poor life expectancy (end-stage peripheral-organ diseases, malignant tumor, massive pulmonary embolisms in cancer patients, chemotherapy-induced chronic cardiomyopathy, etc.) • Severe aortic valve regurgitation • Severe vascular disease with extensive aortic and peripheral vessel involvement (calcification, stenosis, and closure), including axillary arteries • Acute Type A or B aortic dissection with extensive aortic branches (ascending, supra-aortic and femoral) involvement (preoperatively) • Severe neurologic impairment (i.e., prolonged anoxic brain damage, extensive trauma and bleeding) • Severe immunologic disease with marked blood and coagulation disorders • Liver cirrhosis (Child-Pugh class B and C) Pre-ECMO Risk Prediction (Risk Scores) In the last few years, several risk scores have been proposed to assess the VA ECMO patient outcomes, to stratify patients’ risk of mortality, and to improve the patient selection. The survival after VA ECMO score (Table 2) is a survival prediction score based on the large pre-ECMO assessment data extracted from the ELSO registry.7 The survival after VA ECMO score is the first reported in-hospital survival prediction model for ECLS use in cardiogenic shock but does not apply to postcardiotomy settings. Other scores have been designed regarding ECMO in cardiogenic shock, including general or specific VA ECMO settings and described in Table 3.8–10 Table 2. - The SAVE Score6 Parameter Score Acute cardiogenic shock diagnosis group (select one or more) Myocarditis 3 Refractory VT/VF 2 Post heart or lung transplantation 3 Congenital heart disease –3 Other diagnoses leading to cardiogenic shock requiring VA ECMO 0 Age (yrs) 18–38 7 39–52 4 53–62 3 ≥63 0 Weight (kg) ≤65 1 65–89 2 ≥90 0 Acute pre-ECMO organ failures (select one or more if required) Liver failure* –3 Central nervous system dysfunction† –3 Renal failure‡ –3 Chronic renal failure§ –6 Duration of intubation before initiation of ECMO (h) ≤10 0 11–29 –2 ≥30 –4 Peak inspiratory pressure ≤20 cmH2O 3 Pre-ECMO cardiac arrest –2 Diastolic blood pressure before ECMO ≥ 40 mm Hg¶ 3 Pulse pressure before ECMO ≤20 mm Hg¶ –2 HCO3 before ECMO ≤15 mmol/L¶ –3 Constant value to add to all calculations of SAVE score –6 Total score –35 to 17 Total SAVE score Risk class Survival (%) >5 I 75 1–5 II 58 –4 to 0 III 42 –9 to –5 IV 30 ≤ –10 V 18 An online calculator is available at www.save-score.com.*Liver failure was defined as bilirubin ≥33 µmol/L or elevation of serum aminotransferases (ALT or AST) >70 UI/L.†CNS dysfunction combined neurotrauma, stroke, encephalopathy, cerebral embolism, as well as seizure and epileptic syndromes.‡Renal dysfunction is defined as acute renal insufficiency (e.g., creatinine >1.5 mg/dl) with or without RRT.§Chronic kidney disease is defined as either kidney damage or glomerular filtration rate <60 ml/min/1.73 m2 for ≥3 mo.¶Worse value within 6 h prior ECMO cannulation.ALT, alanine transaminase; AST, aspartate aminotransferase; ECMO, extracorporeal membrane oxygenation; CNS, central nervous system; RRT, renal replacement therapy; SAVE, Survival After Venoarterial Extracorporeal Membrane Oxygenation; VF, ventricular fibrillation; VT, ventricular tachycardia. Table 3. - Published Risk Scores for Venoarterial Extracorporeal Life Support, Besides the SAVE Score Risk Score Name Reference VA ECMO Setting Predictors ENCOURAGE Score7 Cardiogenic shock(post AMI) Age, sex, BMI, Glasgow Coma Scale, creatininemia, serum lactate value, prothrombin activity REMEMBER Score8 Post cardiotomy cardiogenic shock(post CABG) Older age, left main coronary artery disease, Inotropic score, CK-MB, serum creatinine, platelet count CARDShock Score9 Cardiogenic shock Older age, neurologic status, previous myocardial infarction or CABG, blood lactate value, acute coronary syndrome etiology, LV systolic dysfunction, estimated glomerular filtration AMI, acute myocardial infarction; BMI, body mass index; CABG, coronary artery bypass grafting; CK-MB, creatinine kinase-myocardial band; LV, left ventricular; VA ECMO, venoarterial extracorporeal membrane oxygenation. Recommendations VA ECMO should be considered for cardiogenic shock within 6 hours of its occurrence, refractory to conventional pharmacological and fluid therapy, and in patients with reversible cardiocirculatory collapse or those eligible for alternative cardiocirculatory assistance, for example, ventricular assist devices (VADs) or transplantation. Etiologies compromising appropriate ECMO function (aortic insufficiency) should be considered to represent potential contraindications. Age, per se’, should not be used as an absolute contraindication. Prognostic score may be used to provide information regarding decision making before ECMO. Poor life expectancy, severe liver disease, acute brain injury, vascular disease, and immunocompromise represent exclusion criteria for ECMO application. Cannulation, Distal Perfusion, and Left Ventricular Venting All aspects and information regarding ECMO circuits, systems, and modes are also presented in other ELSO position papers and in the ELSO Red Book.2–4 Peripheral Cannulation Peripheral VA ECMO cannulation is the most frequently applied for access and performed via the common femoral artery and vein just below the inguinal ligament and above their respective bifurcations (Figure 2). A 15–17 French arterial cannula is usually adequate to supply sufficient flow depending on the patient’s needs. Larger 19 or 21 French cannulas may be necessary in rare clinical scenarios such as sepsis when higher flow is desired.11 Larger arterial cannulas might be associated with increased vascular complications, including limb ischemia.Figure 2.: Right femoral vascular anatomy demonstrating relationship between the common femoral artery, vein, inguinal ligament, and femoral head.Although the result of expert-opinion only, it is felt preferable to place the arterial and venous cannulas in separate limbs to reduce vascular complications and to facilitate decannulation. If feasible, the venous cannula should be placed in the right femoral vein as it is a more direct path to the IVC and right atrium (Figure 3).12Figure 3.: Bilateral peripheral VA ECLS cannulation demonstrating the relationship of the venous and arterial cannula, distal perfusion cannula and distal NIRS patches (modified from Rupprecht et al.).12 NIRS, near-infrared spectroscopy; VA ECLS, venoarterial extracorporeal life support.Image-guided cannulation, particularly vascular ultrasound as a first choice, is recommended. Fluoroscopy can be useful in certain circumstances, for example, implantation in the cath lab. Vascular ultrasound should be started in the short axis and longitudinal views. We recommend starting in the short-axis view, identifying the common femoral artery and vein, the superficial and profunda femoral arteries (Figure 4A), then rotating 90° to the longitudinal view. This affords visualization of the common femoral artery and bifurcation (Figure 4B). It optimizes anterior entry of the needle into the vessel and avoids posterior wall puncture. In addition, using the femoral head as a landmark can ensure vascular access is at a compressible portion of the vessel and avoids pelvic entry (Figure 4C). Similar techniques are recommended for entering the common femoral vein.Figure 4.: A: Vascular ultrasound in short axis of demonstrating the relationship of the CFA and CFV, the bifurcation of the SFA and PFA, inguinal ligament and femoral head. Note the FV courses below the superficial femoral artery. B: Longitudinal vascular ultrasound of the CFA as it bifurcates to the superficial femoral artery and the PFA. C: Longitudinal vascular ultrasound of the femoral artery demonstrating the relationship to the femoral head and the needle entry position of the arterial return cannula and the distal perfusion catheter (By courtesy of Dr. Wallace Ngai, Hong Kong). CFA, common femoral artery; CFV, common femoral vein; FV, femoral vein; PFA, profound femoral artery; SFA, superficial femoral artery.After administration of adequate anticoagulation, a standard guidewire is advanced in the respective vessels and a series of progressive dilations are performed to facilitate cannula insertion. In certain situations, such as obesity, tortuous anatomy, and peripheral vascular disease, a stiff guidewire may be needed for support. The cannulas are then advanced into their respective femoral artery and vein. Imaging (ultrasound, fluoroscopy, or x-ray film) is recommended to confirm initial wire position, directing the advancement of the guidewire, and confirming placement of the arterial and venous drainage cannulas (Figures 5 and 6). Standard chest x-ray film is sufficient to confirm appropriate cannula position after implant.Figure 5.: Fluoroscopy position of the guidewire in the SVC and the tip of the drainage cannula at the SVC/RA junction (By courtesy of Dr. Wallace Ngai, Hong Kong). SVC, superior vena cava; RA, right atrium.Figure 6.: Cardiac echocardiography in the subcostal view demonstrating guidewire position in the IVC/RA junction. IVC, inferior vena cava; RA, right atrium.Subclavian or axillary artery cannulation can be used as a form of peripheral access.2 This access may be used in patients with peripheral vascular disease or very difficult femoral artery access so as to prevent vascular cannulation complications occurring at the femoral artery site, including leg ischemia, bleeding, vascular perforation or rupture, and inadequate cannula size. Furthermore, this access site can (a) minimize differential oxygenation, (b) facilitate patient mobilization in the case of a predicted long VA ECMO run, and (c) allow transition to isolated LV support. In this case, a pseudo-percutaneous approach or the use of a tube graft connection to the axillary artery may be helpful with incision closure while minimizing infection complication. As opposed to ischemia, upper limb hyperperfusion with arm swelling is the more common vascular complication as a result of high ECLS flow with no limitation to ipsilateral limb perfusion, as can occur in the case of a “chimney technique” with a prosthetic graft, as discussed later in this section. The cannulation of the subclavian artery may be carried out similarly, directly or with a “chimney graft” for access. Finally, although usually confined to the pediatric population, carotid artery cannulation can be used for arterial access, recognizing the increased risk of acute brain injury,13 thereby making it the access of last resort when femoral, axillary/subclavian, or a central approach are not feasible. Distal Perfusion With peripheral femoral cannulation, distal perfusion ipsilateral to the femoral artery cannulation is recommended.2 Distal perfusion catheters should be placed under ultrasound guidance or under direct vision into the superficial femoral artery. If the approach is percutaneous, access should start with a puncture in the common femoral artery below the arterial cannula but above the bifurcation and guided into the superficial femoral artery (Figure 4C). Confirmation of the guide wire in the superficial femoral artery by ultrasound or fluoroscopy may be considered, and confirmation of flow by continuous-flow Doppler and ultrasound of the popliteal artery is recommended. When using smaller 15 Fr and 17 Fr arterial cannulas, distal limb perfusion may not be always needed with decision making informed by Near-Infrared Spectroscopy (NIRS). Tissue saturation by NIRS should be above 50%, preferably 60%, and there should be less than a 20% difference between the two extremities. In principle, however, distal perfusion is recommended with a short 6 Fr–8 Fr armored cannula.2 Larger and longer sheaths may be associated with vascular trauma and spasm. The sidearm of the distal perfusion sheath is connected with short tubing using a male-to-male connector to the vent port of the arterial cannula (Figure 3). Retrograde limb perfusion through the dorsalis pedis or the posterior tibial arteries might be also considered not requiring any fluoroscopy or echo guidance to perform it.2 When possible, measurement of flow confirms adequate tissue perfusion, targeting at least 100 ml/min. Finally, it is recommended that distal limb perfusion be accomplished at the time of ECMO institution, preventing any delays in limb perfusion. Left Ventricular Venting Strategies A major disadvantage of VA ECMO is the potential for significant LV loading and distension due to the increase in aorta afterload and associated poor LV ejection. This may be especially harmful for the acutely infarcted left ventricle. High afterload and poor LV ejection may impair aortic valve opening leading to acute pulmonary edema or catastrophic thrombosis of the left-sided cardiac chambers or the aortic root. Thus, the threshold for LV venting in VA ECMO should be low and initially guided by the clinical/imaging scenario (Figure 7).14Figure 7.: Criteria to be used for the assessment of LV unloading need.13 AV, aortic valve; bpm, beats per minute; CVP, central venous pressure; IABP, intra-aortic balloon pump; LA, left atria; LV, left ventricular; PCWP, postcapillary wedge pressure; SVCO3, superior vena cava oxygen saturation.Pulmonary edema on chest x-ray film, a pulse pressure less than 5–10 mm Hg, LV “smoke-like” visualization, and a closed aortic valve with LV distension on echocardiogram all should trigger prompt intervention.14 Noninvasive techniques, including a reduction of ECMO flow while still sustaining effective end-organ perfusion, vasodilation to directly reduce peripheral arterial resistance, increased PEEP to reduce pulmonary arterial flow and enhance right cardiac drainage toward the ECMO system, or moderate inotropic support to maintain LV ejection, all represent possible noninvasive approaches to managing LV distension.14 In principle, impaired LV unloading compromises myocardial recovery and should be addressed immediately when present (Table 4). Table 4. - Options, Procedures, and Related Efficacy Potentially Available to Pursue or Favoring Left Ventricular Unloading During Venoarterial Extracorporeal Life Support Type of Procedure Efficacy Less-invasive maneuvers Reduced ECMO flow √√√ Inotropes √√ Vasodilation √√ Increased PEEP √√ Diuretics √ Invasive (catheter-based) maneuvers Trans-aortic suction device Impella √√√√√ Pulsatile trans-aortic suction device √√√ Atrial septostomy √√√ - √√√√ Left ventricular venting through the apex √√√√√ Left ventricular venting through the mitral valve √√√√√ Pulmonary artery venting √√√ IABP √√ Tran-septal atrial cannula √√√√ Additional venous cannula √√ Central ECLS √√√ ECMO, extracorporeal membrane oxygenation; PEEP, positive end-expiratory pressure; IABP, intra-aortic balloon pump. Various strategies for more aggressive LV venting and unloading include the temporary percutaneous axial flow LV assist device (LVAD) (Impella; Abiomed, Danvers, MA), atrial septostomy or direct drainage, or direct LV apical cannulation and decompression. Intra-aortic balloon pump with inotropes may assist in unloading as well, but data to support this practice are still limited although widely practiced. The favorable impact of LV venting on weaning and early survival have been recently highlighted15,16 indicating that such an important aspect of cardiac support with VA ECMO must receive adequate attention and monitoring to enhance appropriate and timely intervention. Central Cannulation Particularly in the presence of severe peripheral vascular disease at the femoral/iliac levels, central cannulation is usually adopted in the postcardiotomy setting, although recent investigations indicate that even in this setting, if possible, intraoperative transition to a peripheral approach provides better outcomes.2 When central cannulation is decided upon postcardiotomy, use of the CPB-related cannulas (ascending aorta for perfusion and right atrium for drainage) is common. The adoption of prosthetic graft attached to the aorta is usually instituted after aortic surgery but can be adopted also as a solution to allow sternal closure.17 There are several advantages and disadvantages when comparing central to peripheral cannulation (Table 5); however, peripheral cannulation appears linked to better ultimate outcomes and should be considered preferable to a central approach, even in postcardiotomy patients.18,19 Table 5. - Advantages and Disadvantages of Central vs. Peripheral Cannulation in Patients Undergoing Postcardiotomy Extracorporeal Membrane Oxygenation17 Advantages Disadvantages Central cannulation (aortic/atrial) Use of originally (cardiopulmonary bypass) implanted cannulas Opened sternum (chest closed possible) Antegrade flow High bleeding risk Better drainage (bigger right atrium cannulas) Cardiac compression (if exit port subxiphoid—use different exit sites if possible) Long-lasting support (subclavian artery use) Resternotomy to remove cannulas Higher ECMO flow (better unloading through the right atrium drainage) More infection (sepsis) Patient mobilization (particularly with subclavian artery access) Higher rate of cerebral emboli More options (and more easily) for LV venting Higher risk of closed aortic valve Lower risk of differential oxygenation Peripheral cannulation (percutaneous) Femoral artery No surgical Incision Leg ischemia Reduced bleeding risk Retrograde flow (LV afterload increase) Closed sternum Not suitable for long-lasting support No cardiac compression Lower ECMO flow Easier switch to VAD implant Vascular complication (during cannulation or after decannulation) No resternotomy for cannulas removal Reduced options for LV venting (percutaneous) Peripheral cannulation (open) Femoral artery Visualization of peripheral vessel and appropriate cannulation site Lower limb compartment syndrome (in the majority of cases distal perfusion required) Reduced bleeding than central access Retrograde flow (LV afterload increase) Closed sternum Less suitable for prolonged support—reduced patient mobility No cardiac compression Lower ECMO flow (limited right chamber unloading) Axillary artery Avoidance of leg ischemia Upper limb compartment syndrome Avoidance of Harlequin (North/South) Syndrome Upper limb hyperperfusion syndrome (with graft interposition) Patient mobility if prolonged support (bridge to) required Higher bleeding risk (site of cannulation) Visualization of peripheral vessel and appropriate cannulation site Higher cerebral embolic risk Reduced bleeding than central access Lower ECMO flow (limited right chamber unloading) Closed sternum Retrograde flow (LV afterload increase, but less than femoral access) No cardiac compression Higher rate of vascular complications Time consuming ECMO, extracorporeal membrane oxygenation; LV, left ventricular; VAD, ventricular assist device. Recommendations Peripheral cannulation may be associated with improved outcomes, and in cases of severe vascular disease, subclavian, or axillary artery cannulation should be considered. Ipsilateral limb perfusion is recommended at the time of initial femoral artery cannulation. Central cannulation may be considered in postcardiotomy and when faced with severe peripheral vascular disease. LV venting should be immediately addressed when LV distension is present as it is associated with increased weaning rates and early survival (data to be confirmed). LV venting can be noninvasive or invasive with MCS or with left-sided percutaneous or direct cannulation. Configurations and Peculiarities Factors considered when planning the initial cannulation strategy for MCS include: the underlying cause of cardiac dysfunction and projected time course of recovery; the severity of pulmonary dysfunction and projected time course of recovery; the functional reserve of each ventricle; the presence and severity of valvular pathology; risk of arterial access and size of vessels; the severity of coagulopathy and risk of sternotomy; planned future surgery, such as durable VAD implantation or transplant. For patients with predominant cardiac failure and preserved pulmonary function, there are several options for MCS based on ECLS circuitry (Table 6). Table 6. - ECMO Strategies for Temporary Mechanical Circulatory Support in Isolated Cardiac Failure ECLS Strategy Principle Indication(s) Peripheral VA ECMO (return FA) • Default strategy for potentially reversible cardiogenic shock of any cause. Central VA ECMO (return aorta) • Failure to wean from CPB where recovery expected within 7 d• Salvage for small patients with cardiogenic shock where femoral arterial access inadequate VA ECMO (return axillary artery) • Reversible cardiogenic shock where high flows not required• Reversible cardiogenic shock with lower limb vascular disease.• Post aortic dissection operation Centrifugal LVAD (access LA/LV, return aorta) • Isolated LV support where recovery is expected in 8 weeks Centrifugal RVAD (access RA, return PA) • Isolated RV support where recovery is expected in 8 weeks Centrifugal BiVAD • Biventricular support where recovery is expected in 8 weeks CPB, cardiopulmonary bypass; ECLS, extracorporeal life support; FA, femoral artery; FV, femoral vein; LA, left atrium; LV, left ventricle; LVAD, left ventricular assist device; PA, pulmonary artery; RV right ventricle; RVAD, right ventricular assist device; VA ECMO, venoarterial extracorporeal membrane oxygenation. Given its less invasive nature (compared with thoracic access), peripheral VA ECMO, with attention to avoid or minimize LV distension, is a viable first-line option for patients with isolated acute cardiac failure refractory to conventional management. The limitations of peripheral VA ECMO have prompted the use of ECMO devices to facilitate LV unloading by changing to a temporary LVAD or a biVAD configuration (Figure 8).20Figure 8.: Provision of biventricular assistance along with respiratory support. The extracorporeal membrane oxygenation system can be used as a biventricular assist device along with respiratory support provided by the oxygenator in the circuit (adapted with permission from SAGE Publications).34 LVAD, left ventricular assist device; RA, right atrium.Any perfusion strategy that creates a right to left shunt requires an oxygenator in the circuit. Oxygenators may additionally provide temperature control. This strategy effectively provides biventricular support and gas exchange through a single pump configuration with the ability to cease right ventricular (RV) support when not required. However, this configuration requires sternotomy and cannulation of the left ventricle (or left atrium) and aorta. Reoperation (sternotomy or thoracotomy) is then required for explantation of the cannula upon cardiac recovery or for implantation of a long-term mechanical assist device. Less invasive techniques for temporary cardiorespiratory support, including a t