RESUMEN
Although unexplained thrombotic failures still exist, the majority of free-flap failures are due to identifiable technical failures, indicating that an excellent operative technique remains the key point. However, some clinical circumstances, such as damaged or deeply located vessels, are related to a higher thrombotic risks, demanding refinements of the microsurgical procedure to avoid higher failure rates. We reviewed 195 free flaps in the lower leg in order to quantify these situations and how we dealt with them. In total, six flaps were performed with a T-interposition to cope with difficult end-to-side anastomoses on damaged vessels. In two cases, the use of a funnel-shaped vein graft facilitated difficult end-to-side anastomoses in the popliteal area. The authors believe that these refinements of microsurgery should not be first-choice procedures, but they have proven to be a useful tool for certain microsurgical reconstructions.