The extended transverse musculocutaneous gracilis flap: vascular anatomy and clinical implications.

BACKGROUND: The transverse musculocutaneous gracilis (TMG) flap has been used in autologous breast reconstruction, but disadvantages include a small flap volume; therefore, it is only used in small-to-moderate breast reconstructions. We investigated the vascular territory of this flap and the possibility of extending its dimensions.

METHODS: Ten circumferential thigh adipocutaneous flaps attached to the gracilis muscle were harvested from adult cadavers. The following parameters were recorded: diameter and length of pedicles, distance of pedicles from pubis, and number and locations of cutaneous perforators. The major pedicles were injected with contrast and subjected to 3-dimensional computed tomography scanning. Images were viewed using both General Electrics and TeraRecon systems, and the vascular territories were measured. Flaps were then incised to include only tissue that was perfused with contrast, and measured for weight and volume.

RESULTS: The major pedicle had a mean length of 6.7 cm, diameter of 2.2 mm, and distance from pubis of 8.6 cm. There was a mean of 4.3 cutaneous perforators associated with this flap. Three-dimensional images from contrast injection of the major pedicle showed a cutaneous vascular territory that extended more posteriorly than anteriorly, and had a vertical component. Tissue perfused with contrast had a mean weight of 573 g and volume of 617 mL. Two clinical cases were included to show applications of the extended TMG flap.

CONCLUSION: The dimensions of a TMG flap can be increased horizontally (superoposterior thigh) as well as vertically. The vertical portion can be harvested either by undermining the skin inferior to the lower transverse skin incision or by raising a trilobed skin paddle to harvest even more tissue from the medial thigh.