Ex-vivo oxygenated perfusion of free flaps during ischemia time: a feasibility study in a porcine model and preliminary results.

Background: Under ideal circumstances, creation of the anastomosis during free flap transfer is a routine task and can be performed under short ischemia time. However, vessels may be in suboptimal state due to atherosclerosis, radiotherapy or trauma, increasing difficulties regarding receptor vessel identification, and anastomosis which in turn may lead to lengthening of ischemia time resulting in postoperative wound problems or even flap loss. In the current pilot study, a modified heart-lung machine was assembled to achieve continuous oxygenated extracoporeal perfusion using porcine myocutaneous rectus abdominis flaps, aimed at minimizing tissue damage occurring during ischemia time.

Materials And Methods: Different pilot test groups with n = 2 were created, including oxygenated perfusion with heparinized autologous blood or organ preservation solutions. Control groups included short flush with preservation solution followed by cold storage.

Results: Flaps were successfully attached to the modified heart-lung machine while maintaining stable flow throughout the 24-h experiments. Flaps undergoing continuous oxygenated perfusion with preservation solutions showed minimal or no signs of cell necrosis during the 24-h experiment, in contrast to using heparinized autologous blood or flushing and cold storage.

Conclusions: The use of a modified heart-lung machine for oxygenated perfusion of free flaps provides new possibilities to minimize tissue damage during ischemia time, and further study of its use is warranted.