Drainage insufficiency is a common phenomenon during extracorporeal life support, related to a variable and potentially multiple etiologies. Being associated with impaired extracorporeal blood flow (EBF), so with impaired extracorporeal life support (ECLS), and with potential damage to vascular structures, it requires utmost awareness and prompt implementation of an algorithmic approach to identify and treat contributing factor(s).

We believe that the severe, recurrent, and refractory episodes of drainage insufficiency that we experienced in the present case, rather than promoting the growth of fibrin/proteinaceous sheath on the drainage cannula, were induced by the presence of the sheath itself. This, developed as a catheter-induced activation of coagulation cascade, could have partially enveloped the multistage drainage cannula in the inferior vena cava (IVC), as illustrated in Figure 1. The sleeve, occluding some of drainage holes or drainage hole rows, may have decreased the inlet pressure at the level of the unobstructed holes. The lower inlet pressure (augmented negativity) would have increased the risk of collapse of the IVC on the cannula, arising drainage insufficiency, with swinging inlet pressure, drainage tubing “chattering,” and inconsistent EBF,³ without any other evident cause and any substantial response to fluid challenge.