“…During his first ECP session at our facility, we noticed that the central venous catheter (CVC) had a symmetrical tip design with equal priming volumes in both arterial and venous lines (1.9 mL). Building upon our prior knowledge of the “recirculation” phenomenon during ECP, 1 we analyzed the collection efficiency 2 (CE 2 ) of the double‐needle (DN) versus single‐needle (SN) modes used in the first and second procedures, respectively. Based on the results from cycle 1, we employed the same methodology in cycle 2 to validate these findings.…”