title: Prevention of caval collapse during venous drainage for CPB.
abstract: A new plastic self-expanding Smartcanula (Smartcanula LLC, Lausanne, Switzerland) is designed for central insertion and prevention of caval collapse. The objective of our work is to assess the influence of the new design on atrial chatter. Caval collapse over the entire caval axis, right atrial, hepatic, renal vein, and iliac vein is realized in drainage tubes with holes at 5 cm distance intervals. Smartcanulas with various lengths (26 cm [= right atrial], 34 cm [= hepatic], 43 cm [= renal], and 53 cm [= iliac]) versus two-stage cannulas are compared. Pressure drop (ΔP) is measured using Millar pressure-transducers. Flow rate (Q) is measured using an ultrasonic flow meter. Cannula resistance is defined as the ΔP/Q ratio. Data display and recording are controlled using LabView virtual instruments. At an 88 cm height differential, Q values are 8.69 and 6.8 l/min, and ΔP/Q ratios are 0.63 and 1.28 for the 26-cm Smartcanula and the reference cannula, respectively. The 34-cm Smartcanula showed 8.89 l/min and 0.6 ΔP/Q ratio vs. 7.59 l/min and 0.9 for the control cannula (P < 0.05). The 43-cm and 53-cm Smartcanulas showed Q values of 9.04 and 8.81 l/min, respectively, and ΔP/Q2 ratio of 0.6. The Smartcanula outperforms the two-stage cannula, and direct cannula insertion without guide wire is effective.
authors.affiliation: Department of Cardiovascular Surgery, University Hospital CHUV, CH-1011 Lausanne, Switzerland. saad.abdel-sayed@chuv.ch
authors.forename: Saad
authors.initials: S
authors.lastname: Abdel-Sayed
authors.forename: Julien
authors.initials: J
authors.lastname: Favre
authors.forename: Steven
authors.initials: S
authors.lastname: Taub
authors.forename: Ludwig-Karl
authors.initials: LK
authors.lastname: von Segesser
mesh_terms: D001783:Blood Flow Velocity; D001794:Blood Pressure; D002404:Catheterization / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D002405:Catheterization, Central Venous / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D004868:Equipment Failure; D018056:Hemorheology; D006801:Humans; D057446:Hydrodynamics; D008955:Models, Cardiovascular