Neovascularization in the "Cross-Leg Fashioned" Muscular Free Flap

For the reconstruction of soft tissue defect combined with open fracture in the lower leg, free flap, especially muscle free flap which has abundant blood supply, is considered to be the most suitable method. Sometimes, however, injury to the main vessels in the lower leg makes it impossible to use a principal vessel as a recipient vessel. In such cases, vein graft or end-to-side anastomosis can be employed. To acquire a healthier vessel as a recipient,the authors performed crossleg muscle free flap, using a non-injured healthy vessel of the contralateral leg as a recipient vessel. Controversy still lingers over the angiogenesis of cross-leg muscle free flap and thus safety after flap detachment. There have been some clinical case reports on cross-leg muscle free flap, but flap survival after pedicle detachment has been known to be variable according to different authors. Because of the uncertainty of neovascularization in muscular free flap at the time of flap delay procedure,many surgeons hesitate to use a pure muscle free flap as a delay flap. Eight cases of cross-leg muscular free flap were performed by the authors using the rectus abdominis muscle, latissimus dorsi muscle and a combination of the latissimus dorsi and serratus anterior muscle flap. During the operation, the authors estimated the ratio of poorly vascularized bed in recipient soft tissue defect. Despite the high ratio of non-vascularized bed, there was no flap necrosis after pedicle detachment and ample neovascularization within the muscle was confirmed by post-division angiogran. As well, there was no recurrence of osteomyelitis. Conclusively, enough neovascularization in cross-leg free muscle flap, even placed on a poorly vascularized bed, could be induced through a delayed procedure.ope