Effects of arterial blood supply on the survival of reverse-flow island flaps: an experimental study

Abstract

Objectives: This study aimed to investigate the effect of arterial blood supply on the survival area of retrograde island flap.

Methods: The vein and saphenous artery in rabbits were selected to design the reverse-flow island flap experimental model. Forty rabbits were randomly divided into four groups: control group (group A), partial anastomosis of the saphenous artery group (group B), partial anastomosis of the vein group (group C), and no superficial vein group (group D). Flap survival was observed postoperatively, the survival area was measured, and the survival rate was compared. Blood distribution in the flap at different time points was observed by radionuclide imaging.

Results: The blood vessel distribution and blood cell status were observed histologically. The survival rate of flaps in group B was higher than that of the other three groups (P < 0.05). The radioactive material (RM) could be seen clearly in group B, whereas those in groups A, C, and D existed transiently. The RM in group B was higher than that in groups A, C, and D (P < 0.05). On postoperative day 10, group B had more capillary regeneration and blood cells than the other three groups (P < 0.05).

Conclusions: Increasing blood supply can improve the survival rate of flaps, but simply promoting venous return has no significant effect on the survival rate of flaps.

Keywords: Reverse-flow island flaps; pressurization; survival rate; venous drainage.

Figure 1

A. Anatomical diagram of the lower limb of the experimental animals, design of the saphenous artery retrograde island flap, and flap vascular clip anastomosis. B. After the ligation of the saphenous artery and great saphenous vein (not pictured), the flap is lifted to the far end. After the flap is cut, the communicating structures in the deep tissue are ligatured. Postoperative treatment: a translucent membrane is placed in between the flap and deep tissue to block deep tissue drainage in the skin flap; the flap suture in situ. C. The distal saphenous artery is cut and trimmed to half of its diameter, and end-to-end anastomosis is then performed to simulate the distal peripheral artery. D. After the great saphenous vein near the heart is cut, the lumen is trimmed by half, and end-to-end anastomosis simulates the distal peripheral vein.

Figure 2

General observation of flaps. A. Completely necrotic skin flap that appeared pale. B. 10 days after the operation, the skin flap appeared ruddy. All survived and had hair. C. After the operation, the skin flap appeared ruddy and showed only small areas of black necrosis. D. The distal part of the flap appeared darker.

Figure 3

Results of the radionuclide imaging. A. Group A: On the day of surgery, nuclide imaging was performed for visible radionuclide distribution. B. Group A: After the second day, radioactive material was not obvious on the nuclide image. C. Group B: On the day of surgery, nuclide images showed visible nuclide evenly distributed. D. Group B: After the second day, nuclide images showed evenly distributed nuclide. E. Group C: On the day of surgery, nuclide imaging indicated obvious nuclides. F. Group C: Nuclide images after the second day. G. Group D: On the day of surgery. H. Group D: After the second day. I. The statistical results of groups A, B, C, and D. A is the control group, B is part anastomosis of the saphenous artery group, C is part anastomosis of the vein group, and D is the no superficial vein group.

Figure 4

Comparison of the flap survival rate between groups. A. Control group. B. Partial anastomosis of the saphenous artery group. C. Partial anastomosis of the vein group. D. No superficial vein group. *P < 0.05, **P < 0.01.

Figure 5

Histological detection (magnification =200 ×; scale bar =200 µm). A. Control group, the flap with increased fibrous scar tissue. B. Partial anastomosis of the saphenous artery group, with skin flap with capillary regeneration and visible blood cells. C. Part anastomosis of the vein group, only a small amount of blood capillary regeneration in skin flap. D. No superficial vein group, site with a small amount of blood capillary in regeneration.