Adaptors, cannulas, caps, tube couplers, and systems thereof provide endovascular access through an established ECLS system. Adaptors having curved or angled shafts navigate right angle side ports of standard bypass cannulas and permit hemostatic introduction and direction of an intervention device to the axial flow path of the cannula lumen and bypass system. A modified cannula having an angled side port is also provided for use as an arterial cannula. A cap having an occluding surface may be inserted into the angled side port to prevent blood from stagnating in the angled side port. A tube coupler is also provided having an access port, such as an angled access port, and may be spliced into an established bypass system for vascular access point. Multiple couplers can be used to provide multiple access points. The adaptors and occlusive cap are interchangeable with each other and with secondary circuits.
