Since the initiation of cardiac surgery using cardiopulmonary bypass, little progress has been made concerning the design of catheters for vascular access. However, in the last few years, research in this specialized field has established that catheter performance not only depends on size but also on the catheter's design. The catheter's drainage hole surface area correlates with its performance, i.e., flow; the ratio of the catheter's diameter to the patient's vein diameter also correlates with flow. These findings should influence the design of future models. An example is presented with the development of the Smartcanula which maximizes hole surface area and minimizes the wall thickness in order to optimize flow rate and vascular access to the patient.