selecting an extension cannula having a distal region coupled to an elongated shaft and a proximal region coupled to an outlet of an ECMO return cannula, the elongated shaft configured so that a blood flow path does not pass through the elongated shaft;

advancing the distal region of the extension cannula within a patient's vasculature via the elongated shaft such that the extension cannula extends from a location proximal to the patient's renal vessels to a location beyond the patient's renal vessels;

fluidically coupling an inlet of the ECMO return cannula to an ECMO machine;

transitioning the extension cannula from a collapsed insertion state to an expanded deployed state when in communication with a blood flow from the ECMO machine; and

delivering the blood flow through a lumen of the extension cannula in the expanded state to the location beyond the patient's renal vessels via an outlet at the distal region of the extension cannula to thereby improve systemic perfusion.