title: A paired membrane umbrella double-lumen cannula ensures consistent cavopulmonary assistance in a Fontan sheep model.
abstract: OBJECTIVE
  The Avalon Elite (Macquet, Rastatt, Germany) double-lumen cannula can provide effective cavopulmonary assistance in a Fontan (total cavopulmonary connection) sheep model, but it requires strict alignment. The objective was to fabricate and test a newly designed paired umbrella double-lumen cannula without alignment requirement.
  
  
  METHODS
  The paired membrane umbrellas were designed on the double-lumen cannula to bracket infusion blood flow toward the pulmonary artery. Two umbrellas were attached, one 4 cm above and one 4 cm below the infusion opening. Umbrellas were temporarily wrapped and glued to the double-lumen cannula body to facilitate insertion. A total cavopulmonary connection mock loop was used to test cavopulmonary assistance performance and reliability with double-lumen cannula rotation and displacement. The paired umbrella double-lumen cannula also was tested in a total cavopulmonary connection adult sheep model (n = 6).
  
  
  RESULTS
  The bench test showed up to 4.5 L/min pumping flow and approximately 90% pumping flow efficiency at 360° rotation and 8-cm displacement of double-lumen cannula. The total cavopulmonary connection model with compromised hemodynamics was successfully created in all 6 sheep. The cavopulmonary assistance double-lumen cannula with paired umbrellas was smoothly inserted into the superior vena cava and extracardiac conduit in all sheep. At 3.5 to 4.0 L/min pump flow, the systolic arterial blood pressure and central venous pressure returned to normal baseline and remained stable throughout the 90-minute experiment, demonstrating effective cavopulmonary assistance support. Double-lumen cannula rotation and displacement did not affect performance. Autopsy revealed well-opened and positioned paired umbrellas, and double-lumen cannulas were easily removed from the right jugular vein.
  
  
  CONCLUSIONS
  Our double-lumen cannula with paired umbrellas is easy to insert and remove. The paired umbrellas eliminated the strict alignment requirement and ensured consistent cavopulmonary assistance performance.
authors.affiliation: Cardiothoracic Surgery Division, Department of Surgery, University of Kentucky, Lexington, Ky. Electronic address: dnwang2@email.uky.edu.
authors.forename: Dongfang
authors.initials: D
authors.lastname: Wang
authors.affiliation: Cardiothoracic Surgery Division, Department of Surgery, University of Kentucky, Lexington, Ky.
authors.forename: Guodong
authors.initials: G
authors.lastname: Gao
authors.affiliation: Cardiothoracic Surgery Division, Department of Surgery, University of Kentucky, Lexington, Ky.
authors.forename: Mark
authors.initials: M
authors.lastname: Plunkett
authors.affiliation: W-Z Biotech, LLC, Lexington, Ky.
authors.forename: Guangfeng
authors.initials: G
authors.lastname: Zhao
authors.affiliation: W-Z Biotech, LLC, Lexington, Ky.
authors.forename: Stephen
authors.initials: S
authors.lastname: Topaz
authors.affiliation: Cardiothoracic Surgery Division, Department of Surgery, University of Kentucky, Lexington, Ky.
authors.forename: Cherry
authors.initials: C
authors.lastname: Ballard-Croft
authors.affiliation: Cardiothoracic Surgery Division, Department of Surgery, University of Kentucky, Lexington, Ky.
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Zwischenberger
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D002302:Cardiac Output; D004867:Equipment Design; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects / Q000295:instrumentation*; D008422:Materials Testing; D008567:Membranes, Artificial; D023421:Models, Animal; D011183:Postoperative Complications / Q000503:physiopathology / Q000517:prevention & control*; D011651:Pulmonary Artery / Q000503:physiopathology*; D011652:Pulmonary Circulation; D012039:Regional Blood Flow; D012756:Sheep; D013997:Time Factors; D062666:Vascular Access Devices; D014682:Vena Cava, Inferior / Q000503:physiopathology*; D014683:Vena Cava, Superior / Q000503:physiopathology*; D014690:Venous Pressure
chemical_list: D008567:Membranes, Artificial