Abstract:

Objective To investigate the effect of different delayed surgeries on microcirculation remodeling of the crossed-flap after modeling single-and multiperforator-based flaps on the back of the mouse, and examine the changes of endothelial nitric oxide synthase (e-NOS) and matrix metalloproteinase-2(MMP-2) of the choke area. How blood flowing through the choke area affects the morphology of choke vessels was also studied. Methods A total of 100 healthy Balb/c mice were randomly divided into a control group(n=10),and three experimental groups (n=30,each).Group A, which the right thoracodorsal perforator was ligated;group B in which both the right thorac odorsal and iliac lumbar perforators were ligated, and group C in which the left thoracodorsal perforator was intact but the rest of other three perforators were ligated.Laser Doppler measureme nts were made preoperatively and postoperatively at the 6th hour, day 1, day 3, day 5 and day 7 in zone C of each group. Morphology changes of the vessels within the flap was observed. HE staining was used to observe changes of choke vessels. Western blotting was performed for protein detection. The proteins were localized by immunohistochemistry. Results Compared with control group, blood flow in the experimental groups had an obvious increase postoperatively,and the difference was statistical significance(P<0.01). The increasing vascular curvature in the choke area of experimental groups was seen.HE staining showed the dilated diameter and the thicken wall. The protein levels of e-NOS and MMP-2 were increased and mainly located in and around the walls of vessels. Conclusion The characteristics of morphology and hemodynamic (microcirculation remodeling) of choke area in experimental groups are different. The delayed surgery that keeps single-perforator intact has the greatest impact on microcirculation remodeling. e-NOS and MMP-2 have an effect on angiogenesis.

Key words: Perforator flap, Choke vessel, Delayed surgery, Hemodynamic, Western blotting, Immunohistochemistry, Mouse