Role of Extracorporeal Membrane Oxygenation in the Treatment of Massive Pulmonary Embolism.

Massive/high-risk pulmonary embolism (PE) is associated with a 30-day mortality rate of approximately 65%. In searching for strategies that may make a dent on this dismal mortality rate, investigators have, over the last decade, shown renewed interest in the potential beneficial role of venoarterial (V-A) extracorporeal membrane oxygenation (ECMO) in the treatment of patients with high-risk PE. There is a dearth of high-quality evidence regarding the value of ECMO in the treatment of massive PE. Studies examining this issue have generally been retrospective, often single center and frequently with small patient numbers. Moreover, these reported studies are not matched with appropriate controls, and, accordingly, it is difficult to regulate for inherent treatment bias. Not surprisingly, there are no randomized controlled trials examining the value of ECMO in the treatment of massive PE, as such trials would pose formidable feasibility challenges. Over the past several years, there has been increasing support for upfront use of V-A ECMO in the treatment of massive PE, when it is complicated by cardiac arrest. In those patients without cardiac arrest, but who have contraindications for thrombolysis, V-A ECMO combined with anticoagulation may be used to stabilize the patient. If after 3 to 5 days, such patients demonstrate persistent right ventricular dysfunction, embolectomy (either surgical or catheter based) should be performed. Well-designed, multicenter, prospective studies are urgently needed to better define the role of V-A ECMO in the treatment of patients with massive PE.