Blood flow and tissue survival in the rabbit venous flap

The extent of venous flow, revascularization, local fluid imbibition, and metabolic status was evaluated in an experimental venous flap model. Thirty-six rabbits divided into six groups of six rabbits each had a 3.5 x 2.5 cm venous flap elevated along the thoracoepigastric vein, connected only by its proximal and distal vein, and sutured back. A composite graft of the same size was created on the contralateral side. Venous flaps survived 14 days, while composite grafts consistently did not. The vascular network was partially filled with fluorescein tracer within an hour after flap creation, even with an underlying Silastic sheet. Filling improved over several days, consistent with rapid revascularization. Composite grafts showed no immediate filling and delayed revascularization. Venous flow was apparently insufficient to enhance metabolism, since both glucose and lactate levels were equivalent between venous flaps and composite grafts. This supports the concept that an enhanced revascularization may be the primary mechanism of survival for venous flaps.