T-anastomosis in microsurgical free flap reconstruction: an overview of clinical applications.

In free flap transfer, the recipient vessel is often sacrificed to provide the pedicle anastomosis. As the recipient vessel is likely necessary for distal circulation, preserving its patency is also important, especially in the extremities of aged or chronic vasculopathy patients, such as those with diabetes. If a reliable proximal branch is included in the T-shaped pedicle preparation, the pedicle can be interposed between two ends of the recipient vessel, thus allowing for T-anastomosis. This technique can be used to preserve recipient flow as well as for other clinical purposes depending on the recipient vessel condition. T-anastomosis was planned in cases that required the recipient flow to be preserved, for example, if peripheral vasculopathy was present. Various clinical applications of T-anastomosis have been performed, such as preserving recipient flow, preserving donor flow, rebuilding deficient vascular flow, balancing and dispersing blood flow or pressure, chimeric patterns, reusing a pedicle in the staged reconstruction or a combination of the above. Vascular systems with reliable proximal branches of the proper diameters, such as subscapular or lateral circumflex femoral vessels, appear to be good source vessels for the T-shaped pedicle. The T-anastomosis was used in 45 cases for single and dual purposes. The dominant recipient vessel was preserved in 11 extremity reconstructions, and a single remnant recipient vessel was saved in six traumatic extremities and four chronic vasculopathy patients. The recipient vessels that were selected for preserving the flow included the posterior tibial (n=21), anterior tibial (n=8), radial (n=3), ulnar (n=2) and other arteries. The source vessel of the latissimus dorsi or anterolateral thigh perforator flap was most often used for preparing the T-shaped pedicle. T-anastomosis of the pedicle in the free flap transfer is another reliable option for preserving recipient flow. In addition, the anastomosis is quite useful in difficult recipient sites and for many purposes, such as chronic diabetes or traumatic vascular injury. With this technique, a single recipient vessel can be reused in a staged reconstruction. In perforator flaps, the concentrated flow through a narrow perforator pedicle with a small diameter can be dispersed until the autoregulation of new flow distribution in the flap is stabilised.