CHEST Guidelines-Echocardiographic-Image-of-a-Cannula-in-the-Inferi

Echocardiographic-Image-of-a-Cannula-in-the-Inferi

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A 16-year-old boy with fulminant myocarditis experienced cardiogenic shock, leading to the use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) for stabilization. Following a week of support, the patient improved and VA-ECMO was discontinued. Subsequent transthoracic echocardiography (TTE) revealed a cannula-shaped structure indicating a thrombus in the inferior vena cava (IVC), suggestive of cannula-associated deep vein thrombosis (DVT).<br /><br />Typically underdiagnosed, cannula-associated DVT is a potential complication post-ECMO decannulation, with risks aggravated by blood flow changes and cannula size, especially when larger cannulas are used. The thrombus, however, in this case, did not cause IVC syndrome or pulmonary embolism symptoms, potentially due to its configuration allowing blood flow. After 10 days of anticoagulation therapy with unfractionated heparin (UFH), the thrombus resolved without further complications.<br /><br />The diagnosis of cannula-associated DVT stems from the lack of compressibility in the vein, absence of blood flow, and direct thrombus visualization, often post removal of ECMO cannulas. While transthoracic echocardiography (TTE) has low sensitivity during ECMO support, it effectively detects DVT following cannula removal. Options for managing such thrombosis include anticoagulation, thrombolytic therapy, mechanical intervention, or surgical removal, with anticoagulation deemed optimal for this patient.<br /><br />The incident reflects a broader challenge of anticoagulation during ECMO: balancing thrombotic risk reduction with hemorrhage prevention. While the procedure allows for continued hemodynamic stability, reliable anticoagulation monitoring remains challenging due to variability in activated partial thromboplastin time (aPTT) reliability. Finally, the lack of universal anticoagulation standards underscores the need for further research to mitigate such risks.

Keywords

fulminant myocarditis

cardiogenic shock

venoarterial extracorporeal membrane oxygenation

VA-ECMO

transthoracic echocardiography

cannula-associated deep vein thrombosis

DVT

anticoagulation therapy

unfractionated heparin

ECMO complications