Preliminary Exploration: When Angiosome Meets Prefabricated Flaps.

 The best known limitation to the use of prefabricated flaps is their limited survival area. One explanation for this is insufficient neovascularization. However, blood flow of prefabricated flaps is through their innate vascular network. This could lead one to conclude that angiosomes may impede blood perfusion. This study aims to settle this contradiction between theory and clinical practice.  We performed a two-stage operation of a prefabricated abdominal flap in a rat model. The rats were divided into five groups ( = 6/group). Group A: fixed pedicle at a horizontal angle; Group B: fixed pedicle at an oblique angle; Group C: fixed pedicle at a vertical angle; Group D: fixed pedicle in the same position as Group A; and Group E: axial flap. Groups A and B were prefabricated for 2 weeks and Groups C and D were prefabricated for 3 weeks. Macroscopic appearance was noted, and analysis of near-infrared fluorescence imaging and capillary density was performed.  There was no significant difference in the flaps' survival area between Groups A and B. Group D had a significantly larger survival area when compared with Group C. The boundary between two angiosomes (medioventral line) seemed to limit the indocyanine green perfusion in Groups B, C, and E, while in Groups A and D, no such limitation was seen. Capillary density was positively correlated with neovascularization time.  Angiosomes impede blood perfusion in prefabricated flaps. Cross-bound neovascular vessels nourish the flap, thus overcoming the limitation of choke vessels.