Effect of recipient arterial blood inflow on free flap survival area

The influence of using different recipient arteries on free flap survival area has not been well studied. The purpose of the authors' present study was to compare the survival areas of free flaps transferred to different recipient arteries with different blood inflow and to investigate the vascular structural changes in the flaps.

The authors developed a free three-territory flap model on the back of a rat. This three-territory flap was elevated based on the thoracodorsal vessels, which were dissected to the axillary vessels. In group 1, the control group (n = 16), the flap was transferred to the abdominal skin defect as a pedicled flap after 60 minutes of clamp ischemia. Groups 2 (n = 24) and 3 (n = 24) were free flap models that were transferred to different recipient vessels. The axillary vessels were anastomosed to the common carotid artery and the external jugular vein in group 2, and to the femoral vessels in group 3. On day 5, evaluation of the survival area of the flap, whole-body angiography, and measurement of arterial inflow to the flap were performed.

The greatest mean flap survival was seen in group 2 (94.3 percent). The differences between groups 1 and 2 and groups 2 and 3 were statistically significant. Angiographic studies demonstrated that the second choke zone in group 2 dilated extensively, but in groups 1 and 3, the second choke zone dilated only slightly or remained unopened.

The results suggest that augmenting the arterial inflow of a free flap could open the second choke zone and improve flap survival area.