Extracorporeal life support offers cardiopulmonary support to allow recovery of the heart and/or lungs or to transition to more definitive therapies. The use of extracorporeal membrane oxygenation (ECMO) in thoracic surgery focuses on two settings. The first is intraoperative utilization to either facilitate surgery or manage an acute cardiopulmonary crisis. The second is in the postoperative setting for complications after surgery. Each setting requires understanding the capabilities of ECMO, the risks and benefits of extracorporeal technology, and even the creative application of this technology for optimal patient outcomes. In this chapter, we discuss the technical aspects of ECMO initiation and the various scenarios the general thoracic surgeon may encounter, including intraoperative ECMO during pulmonary resections and ECMO for postoperative acute respiratory distress syndrome (ARDS).
ECMO INDICATIONS AND CANNULATION
It is important to recognize the dramatic increase in ECMO utilization. An analysis of the U.S. Nationwide Inpatient Sample from 2006 to 2011 demonstrated a 433% increase.1 A similar analysis of ECMO in Germany showed a threefold increase from 2007 to 2012.2 In general, as institutional ECMO volumes increase, the observed mortality improves. This threshold appears to be around 30 ECMO cases annually as evidenced by a report from the Extracorporeal Life Support Organization (ELSO) registry.3
ECMO is indicated for two main reasons: oxygenation and hemodynamics. Both indications may be an issue for the thoracic surgeon. For instance, if performing a complex resection on a patient with limited reserve and challenges with intraoperative ventilation, ECMO can provide oxygenation during the procedure. Also, if the surgeon is working close to the heart for locally advanced tumors that require cardiac manipulation, ECMO can be used to reduce hemodynamic stress on the patient. Both oxygenation and hemodynamic compromise can be an issue postoperatively as well and may require ECMO support. Finally, the thoracic surgeon may also be called on to consider and initiate ECMO for any patient presenting with hypoxic respiratory failure, such as in the setting of ARDS.
The number of absolute contraindications is limited. Patients who have contraindications to systemic anticoagulation or an acute intracranial hemorrhage or stroke should not proceed to ECMO. In general, terminally ill patients with limited life expectancy or patients with widely metastatic cancer should not proceed to ECMO. Since ECMO patients after pulmonary resection were initially deemed suitable candidates for pulmonary resection, some of these threshold criteria have already been considered. Relative contraindications include ventilation for longer than 7 days, especially with high ventilatory support, vascular access limitations, or age older than 65. Again, the criteria in the setting of postpulmonary resection differ from those of the general ARDS patient since the decision to proceed with curative surgery implies a more aggressive stance toward respiratory failure.
Numerous different scoring systems have been developed to predict the likelihood of successful outcomes with ECMO. These include ...