Free flap transfer and the prevention of endothelial damage

Prolonged ischemia is thought to have detrimental effects on the most vulnerable structure of a free flap, the intima. We investigated experimentally and clinically the effects of ischemia on microvascular flaps, with emphasis on the endothelial cell lining and the efficacy of cold storage solutions in preventing endothelial damage. Experimentally, we investigated three cold storage solutions--the Eurocollins solution, Bretschneider's solution, and the University of Wisconsin solution-histologically, submicroscopically, and functionally regarding their ability to protect the intima. The University of Wisconsin solution proved superior to the Eurocollins and Bretschneider's solutions. Our preliminary results on the clinical free flaps confirm a relationship between the duration of ischemia and the secretion of prostacyclin. We therefore recommend that operating teams be organized to allow immediate reanastomosis following free flap elevation. If immediate reanastomosis is not possible, our results indicate that perfusion with the University of Wisconsin solution provides optimal endothelial protection and increases flap viability.