A 55-year-old man with a history of morbid obesity, uncontrolled diabetes mellitus, and smoking presented to the emergency department 48 hours after the onset of chest pain. He was in cardiogenic shock with sinus tachycardia to 120 beats per minute and hypotension with a blood pressure of 87/55 mm Hg. An electrocardiogram (ECG) showed ST elevations and an emergent cardiac catheterization was performed, which demonstrated an occluded left anterior descending artery. The occlusion could not be crossed with a wire and during the procedure the patient went into ventricular fibrillatory arrest. Immediate cardiopulmonary resuscitation was undertaken and despite numerous rounds of pharmacologic therapy and chest compressions, a perfusing rhythm and pressure were not achieved. He was placed on percutaneous venoarterial extracorporeal membrane oxygenation (VA-ECMO) via the femoral vein and femoral artery for acute cardiogenic shock. Over the next 7 days, he was weaned off of VA-ECMO support and was discharged home on optimal medical therapy for his coronary artery disease (CAD).

VA-ECMO is typically considered in the setting of continued end-organ hypoperfusion, despite escalating doses of inotropic support with or without the use of an intra-aortic balloon pump for augmentation. In such cases of refractory cardiogenic shock, VA-ECMO is used to bridge patients to recovery, surgical intervention, transplantation, or left ventricular assist device (LVAD). The most common indications for VA-ECMO include fulminant myocarditis, post-cardiotomy support, acute myocardial infarction (MI), and post heart transplant for early graft failure (Table 36-1). Other indications include refractory ventricular tachycardia or ventricular fibrillation unresponsive to conventional therapy, hypothermia, acute anaphylaxis, pulmonary embolism, peripartum cardiomyopathy, sepsis-related cardiac depression, and drug overdose.

There is no standardized and universally accepted list of contraindications to VA-ECMO. Nonetheless, there are several contraindications that we believe many groups would agree upon (Table 36-2). These include advanced age (>75-80 years), active malignancy with an expected survival of less than 1 year, severe peripheral vascular disease, end-stage renal disease on dialysis, advanced liver disease, current intracranial hemorrhage or other contraindication to systemic anticoagulation, unwitnessed cardiopulmonary arrest with ongoing cardiopulmonary resuscitation, and witnessed cardiopulmonary arrest with prolonged cardiopulmonary resuscitation (>30 minutes) without return of spontaneous circulation.

The VA-ECMO circuit consists of a pump, a membrane oxygenator, a controller, cannulae, and tubing. The pump is usually a centrifugal pump that can generate up to 4000 rotations per minute and flow up to 8 L per minute. The oxygenator functions to eliminate carbon dioxide and to oxygenate blood. It is comprised of a polymethylpentene membrane, which is lower in resistance resulting in less blood consumption, and can be heparin-coated. The controller displays and allows for adjustment of rotations per minute and associated flow.

The drainage cannula is inserted into the venous system. It typically has a larger diameter between 21 and 25 French and can be up to 60 cm in length. The venous drainage cannula can be single or multistage drainage. The return cannula is inserted into the arterial system, is typically 15 to 19 French in diameter, and is shorter with lengths of 20 to 25 cm when inserted peripherally.

TECHNIQUE

In establishing access for VA-ECMO, relevant aspects to consider are the indication for which VA-ECMO is being instituted and any anatomic factors that may hinder placement of cannulae in a specific location. In the post-cardiotomy setting of being unable to wean from cardiopulmonary bypass or in the setting of an emergent resternotomy for a post-cardiac surgical patient, patients are typically cannulated centrally, with the arterial cannula placed in the ascending aorta and the venous cannula placed in the right atrium (Figure 36-1). In the latter scenario of emergent resternotomy, some surgeons will immediately proceed to aortotomy and atriotomy, insert the cannulae with an assistant holding them in place, go on VA-ECMO, and then place purse-string sutures around the cannulae to secure them in place, thereby reducing the amount of time to get the patient on support. If time allows, placing the purse-strings initially with subsequent aortotomy and atriotomy and cannulation in a more controlled sequence minimizes the risk of malpositioning or accidental displacement of the cannulae. With central VA-ECMO, the cannulae are tunneled through the subcutaneous tissues and away from the midline wound, with the sternum and overlying subcutaneous tissue often left open and an Esmarch dressing sewn in place. A left ventricular vent can also be directly inserted and tunneled away from the midline wound to prevent ventricular distension and Y-ed into the drainage cannulae. After successful weaning from VA-ECMO and decannulation, the purse-strings can be tied and the aortotomy and atriotomy oversewn in usual fashion.