A veno-arterial extracorporeal membrane oxygenation (VA ECMO) system comprising: a dual lumen drainage cannula comprising: a first drainage tube having a proximal end, a distal end, and a sidewall extending between the proximal end and the distal end; and a second drainage tube in axial alignment with the first drainage tube and having a proximal end, a distal end, and a sidewall extending between the proximal end and the distal end; a connector configured for connecting to a proximal end of the drainage cannula such that fluid pathways leading from the first and second drainage tubes (12, 14) transition from a coaxial arrangement at a distal end of the connector to an axially-offset arrangement at a proximal end of the connector; a blood pump having a pump inlet and a pump outlet, the pump inlet configured for fluidly connecting to the first drainage tube and the second drainage tube; an oxygenator having an oxygenator inlet and an oxygenator outlet, the oxygenator inlet configured for fluidly connecting with the pump outlet; and an infusion cannula configured for fluidly connecting with the oxygenator outlet, wherein the distal end of the first drainage tube has a plurality of first drainage apertures and the distal end of the second drainage tube has a plurality of second drainage apertures, wherein the first drainage tube and the second drainage tube are fixedly connected to each other at the distal end of the second drainage tube. a dual lumen drainage cannula comprising: a first drainage tube having a proximal end, a distal end, and a sidewall extending between the proximal end and the distal end; and a second drainage tube in axial alignment with the first drainage tube and having a proximal end, a distal end, and a sidewall extending between the proximal end and the distal end; a connector configured for connecting to a proximal end of the drainage cannula such that fluid pathways leading from the first and second drainage tubes (12, 14) transition from a coaxial arrangement at a distal end of the connector to an axially-offset arrangement at a proximal end of the connector; a first drainage tube having a proximal end, a distal end, and a sidewall extending between the proximal end and the distal end; and a second drainage tube in axial alignment with the first drainage tube and having a proximal end, a distal end, and a sidewall extending between the proximal end and the distal end; a connector configured for connecting to a proximal end of the drainage cannula such that fluid pathways leading from the first and second drainage tubes (12, 14) transition from a coaxial arrangement at a distal end of the connector to an axially-offset arrangement at a proximal end of the connector; a blood pump having a pump inlet and a pump outlet, the pump inlet configured for fluidly connecting to the first drainage tube and the second drainage tube; an oxygenator having an oxygenator inlet and an oxygenator outlet, the oxygenator inlet configured for fluidly connecting with the pump outlet; and an infusion cannula configured for fluidly connecting with the oxygenator outlet, wherein the distal end of the first drainage tube has a plurality of first drainage apertures and the distal end of the second drainage tube has a plurality of second drainage apertures, wherein the first drainage tube and the second drainage tube are fixedly connected to each other at the distal end of the second drainage tube.