Extracorporeal membrane oxygenation (ECMO): Radiographic appearances, complications and imaging artefacts for radiologists

Abstract

Extracorporeal membrane oxygenation (ECMO) is a form of cardiopulmonary support primarily used in cardiothoracic and intensive care unit (ICU) settings. The purpose of this review is to familiarise radiologists with the imaging features of ECMO devices, their associated complications and appropriate imaging protocols for contrast-enhanced CT imaging of ECMO patients. This paper will provide a brief introduction to ECMO and the imaging modalities utilised in ECMO patients, followed by a description of the types of ECMO available and cannula positioning. Indications and contraindications for ECMO will be outlined followed by a description of the complications associated with ECMO, which radiologists should recognise. Finally, the imaging protocol and interpretation of contrast-enhanced CT imaging in ECMO patients will be discussed. In the current clinical climate with millions of COVID-19 cases around the world and tens of thousands of critically ill patients, many requiring cardiopulmonary support in intensive care units, the use of ECMO in adults has increased, and thus so has the volume of imaging. Radiologists need to be familiar with the types of ECMO available, the correct positioning of the catheters depending on the type of ECMO being utilised, and the associated complications and imaging artefacts.

Veno-venous extracorporeal membrane oxygenation (VV ECMO) cannula malposition identified with point-of-care ultrasound

“…Minor and major hemorrhage is not uncommon in these patients secondary to anticoagulation and platelet dysfunction. Concurrent thrombocytopenia, hepatic dysfunction and renal failure are not uncommon in these critically ill patients, further contributing to coagulopathy [ 21 , 22 ]. Secondary to prolonged hospital stays, nosocomial infections are common and may contribute to underlying endothelial injury and leakage, further exacerbating hypotension and hypoperfusion.…”

An Imaging Overview of COVID-19 ARDS in ICU Patients and Its Complications: A Pictorial Review

“…Hemorrhages are more frequently observed in patients receiving therapeutic anticoagulation for the prevention of venous thromboembolism [105], but both high levels of proinflammatory cytokines and widespread endothelial cell damage may contribute to their occurrence [106]. Moreover, anticoagulant therapy to prevent the ECMO circuit from clotting and consequently minimize the risk of thromboembolic events may lead to an increased risk for spontaneous hemorrhages anywhere in the body [27].…”

“…ECMO can bypass the lungs through a veno-venous circuit (VV-ECMO), providing quite complete respiratory support. In particular, the VV-ECMO circuit drains venous blood through a cannula commonly positioned in the inferior vena cava, oxygenates the blood with the external membrane oxygenator, and then pumps the blood back into the same venous compartment, generally through a return cannula positioned in the superior vena cava [27]. The use of veno-arterial ECMO (VA-ECMO) in COVID-19 patients is reserved for those with severe respiratory failure accompanied by severe heart failure or other causes of cardiogenic shock.…”

Identifying the cause of cardiac arrest through coronary computed tomography angiography with high heart rate under venoarterial extracorporeal membrane oxygenation support: a case description

“…Coronary CTA (CCTA) has been considered the most effective noninvasive method for evaluating coronary arteries, but traditional CCTA requires heart rate control and respiratory coordination, which are challenging under ECMO support ( 9 ). ECMO can change blood flow, causing difficulties in the venous injection of contrast agents for CCTA examinations ( 10 ). As a result, patients under ECMO are underserved in terms of CCTA examinations.…”