Quantitative relationship between vascular kinking and twisting.

A wide variety of factors causing vascular thrombosis in the microvascular free flap reconstruction have been encountered. The most frequent situation in our experiences has been vascular kinking because of improper positioning. It has been reported that the best way to avoid kinking is to place the vessels at a neutral axis. However, curving the pedicles to match the recipient vessels cannot be avoided, especially in head and neck reconstruction with a large flap and long pedicle. According to our clinical experiences, the curved vascular pedicle needs rotation in its axis from the neutral position to avoid kinking. Furthermore, we noted that the number of loops equals the number of axial rotations of 360°. We propose that these experiences and ideas can have wide applications in various fields of vascular surgery.