Comparison of arterial supercharging and venous superdrainage on improvement of survival of the extended perforator flap in rats.

ABSTRACT

BACKGROUND: Arterial supercharging and venous superdrainage have been the commonly used vascular augmentation techniques for resolving partial loss of flaps in reconstructive surgery. It remains controversial which one of them is more effective in improving flap survival. The purpose of this study was to compare the effect of distal venous superdrainage and arterial supercharging on the survival of an extended dorsal perforator flap in rats. MATERIALS AND METHODS: Sixty Sprague-Dawley rats were randomly divided into three groups (n = 20 in each group). An extended dorsal perforator flap with the size of 3 × 12 cm based on the deep circumflex iliac artery and vein was elevated in each rat. In arterial supercharging group, the thoracodorsal artery was retained as the distal supercharging vessel; In venous superdrainage group, the thoracodorsal vein was retained as the distal superdrainage vessel. In control group, no other arteries and veins were retained except the main vascular pedicle. On the seventh day after operation, the survival area of flap was calculated as a percentage of viable area to the total flap. Vascular changes in the choke zones were assessed by angiography. Microvascular density and diameter were assessed via immunohistochemistry staining of CD31 on the fifth day after operation. RESULTS: The flap survival area in arterial supercharging group was significantly higher than that in venous superdrainage group (98.9 ± 0.8% vs. 81.5 ± 3.5%, p < .001). By gross observation, the extent of dilation of choke zone vessels in venous superdrainage group was smaller compared with that in arterial supercharging group. The density of CD31-positive vessels and the diameter of choke zone vessels in arterial supercharging group were significantly larger than that in venous superdrainage group (23.4 ± 4.6 mm-2 vs. 13.1 ± 4.2 mm-2 , p < .05; and 37.5 ± 5.8 µm vs. 27.8 ± 4.9 µm, p < .05). CONCLUSION: Compared with venous superdrainage, distal arterial supercharging in the potential territory resulted in better survival of an extended dorsal perforator flap in a rat model.