BACKGROUND: Various types of arterial anastomosis are used in the recipient beds of clinical free flap transfers, but their respective hemodynamic efficiencies have not yet been elucidated. The purpose of this study was to investigate the relationship between the type of arterial anastomosis and the area of free flap survival. The authors transferred free three-territory flaps in rats using three different types of arterial anastomosis (end-to-end, end-to-side, and retrograde) and compared their areas of survival. METHODS: Sixty Wistar rats were divided into three groups (n = 20 in each group). A free three-territory flap was elevated and transferred microsurgically to the left ventral region in each rat. The arterial anastomosis was performed in an antegrade end-to-end fashion in group 1, in an end-to-side fashion in group 2, and in a retrograde end-to-end fashion in group 3. The arterial blood flow to the flap was measured 30 minutes after revascularization. On day 5, the area of flap survival was evaluated and whole-body angiography was performed. RESULTS: The average area of flap survival was 90.8 +/- 12.9 percent in group 1, 91.5 +/- 14.3 percent in group 2, and 53.4 +/- 15.5 percent in group 3. There was a statistically significant difference between group 3 and each of the other two groups. CONCLUSIONS: End-to-side and end-to-end arterial anastomoses resulted in an equivalent blood inflow and area of flap survival. Retrograde arterial anastomosis was far inferior to antegrade arterial anastomosis in terms of the area of flap survival, and only the first vascular territory was safe from necrosis.
BACKGROUND: Various types of arterial anastomosis are used in the recipient beds of clinical free flap transfers, but their respective hemodynamic efficiencies have not yet been elucidated. The purpose of this study was to investigate the relationship between the type of arterial anastomosis and the area of free flap survival. The authors transferred free three-territory flaps in rats using three different types of arterial anastomosis (end-to-end, end-to-side, and retrograde) and compared their areas of survival. METHODS: Sixty Wistar rats were divided into three groups (n = 20 in each group). A free three-territory flap was elevated and transferred microsurgically to the left ventral region in each rat. The arterial anastomosis was performed in an antegrade end-to-end fashion in group 1, in an end-to-side fashion in group 2, and in a retrograde end-to-end fashion in group 3. The arterial blood flow to the flap was measured 30 minutes after revascularization. On day 5, the area of flap survival was evaluated and whole-body angiography was performed. RESULTS: The average area of flap survival was 90.8 +/- 12.9 percent in group 1, 91.5 +/- 14.3 percent in group 2, and 53.4 +/- 15.5 percent in group 3. There was a statistically significant difference between group 3 and each of the other two groups. CONCLUSIONS: End-to-side and end-to-end arterial anastomoses resulted in an equivalent blood inflow and area of flap survival. Retrograde arterial anastomosis was far inferior to antegrade arterial anastomosis in terms of the area of flap survival, and only the first vascular territory was safe from necrosis.