Wang-Zwische double-lumen cannula leads to total cavopulmonary support in a failing Fontan sheep model

Background: We are developing a total cavopulmonary support system for failing Fontan physiology using the percutaneous Wang-Zwische double-lumen cannula (DLC).

Methods: We developed a sheep model of failing Fontan physiology through a right thoracotomy in 5 sheep. An extracardiac conduit was anastomosed to the inferior vena cava and superior vena cava, and a graft was applied to connect the conduit and the right pulmonary artery (PA) to create total vena cava-to-PA diversion, excluding the right heart. The DLC (commercialized as AvalonElite, Avalon Laboratories LLC, Rancho Dominguez, CA) was coupled with a CentriMag pump (Levitronix Waltham, MA) to form a cavopulmonary support system. The DLC was inserted through the right jugular vein and the superior vena cava into the extracardiac conduit with the infusion lumen opening aligned with the right PA bridge. Blood was withdrawn from the superior vena cava and the inferior vena cava through the drainage lumen and pumped into the right PA through the infusion lumen, with flow adjusted to 4.0±0.5 L/min.

Results: A successful Fontan model was created without cardiopulmonary bypass. After total venous blood diversion from the vena cava to the right PA artery, failing Fontan physiology developed, evidenced by elevated central venous pressure and dropping mean PA pressure and systolic arterial pressure. The DLC was successfully inserted, and hemodynamics were normalized in all 5 sheep for the duration of the 2-hour study.

Conclusions: We created a model of failing Fontan circulation in sheep without cardiopulmonary bypass. The DLC system achieved total cavopulmonary support for 2 hours in our failing Fontan sheep model.