High-flow femoro-femoral bypass utilizing small cannulae and a centrifugal pump on the venous side

Abstract

Femoro-femoral bypass is an established technique in the armamentarium of cardiac surgeons, but poor venous drainage usually restricts the flow rate that can be achieved. We describe a technique whereby full flow (> 2.41 I/min/m² femoro-femoral bypass) can be achieved with a 17 F arterial and a single 21 F venous cannula placed percutaneously or via a cut-down.

Transoesophageal echo is used to position the tip of the venous cannula accurately in the right atrium. The circuit includes a centrifugal pump on the venous side, pumping into a reservoir; a conventional roller pump delivers blood through the arterial cannula. A parallel arrangement allows the centrifugal pump to be excluded from the circuit at any stage. The system allows flow rates over 2.4 l/min/m ² despite the size of the venous cannula ; without the centrifugal pump working maximal flow rates are under 1.5 l/min/m². The right side of the heart is totally decompressed and there is no need to add volume or vasopressors to maintain the desired full flow rate. Once the chest is open, perfusion may continue as before or gravity drainage can be utilized after stopping the centrifugal pump; venous return may be augmented by placing additional cannulae. If desired, slowing drainage by the centrifugal pump temporarily permits the blind placement of a coronary sinus cannula without entraining air. To avoid inadvertent bolus doses with unpredictable effects while the centrifugal pump is running, no drugs should be administered into the right atrium and all infusions into the neck lines must be through flow-regulating pumps. We have found this system useful for (1) hazardous re-operations, (2) pericardiectomy and (3) emergency bypass, when percutaneous cannulation can be used.