The clinical role of the gracilis muscle: an example of multidisciplinary collaboration

The gracilis muscle is widely used in reconstructive surgery as either a pedicled or free flap for soft tissue coverage or as a functioning muscle transfer. Many studies based on cadaveric dissection have focused on the vascular anatomy of the gracilis muscle providing uncertain data about the number, origin and calibre of its vascular pedicles. Computed Tomography (CT) angiographies of 40 patients (35 males and 5 females, mean age: 63 years) have been analyzed bilaterally to perform a detailed anatomical study of the gracilis vascular supply. The main pedicle penetrates the gracilis muscle at a mean distance (± S.D.) of 10 ± 1 cm from the ischiopubic branch. Its calibre shows a mean value of 2.5 ± 0.5 mm, and it is statistically larger when directly originating from the deep femoral artery versus when arising from the artery of the adductors (p < 0.01). The muscle belly has a mean length of 30 ± 2.1 cm. A significant correlation between the calibre of the main pedicle and the volume of the gracilis muscle was found (p < 0.01). The mean number of the accessory pedicles is 1.8 (range 1-4). Based on the results of our study, a 54 year old woman suffering from a recurrent recto-vaginal fistula underwent CT angiography to plan a proximally pedicled gracilis flap. CT angiography showed that the entrance point into the gracilis muscle was located 10.3 cm distal from the pubis and that the length of the muscle belly was 28 cm. This data was useful for planning the graciloplasty, since that part of the dominant pedicle and the distal myotendineuos junction was long enough for the surgical procedure. Using this information pre-operatively surgeons could minimize the extent of dissection and avoid retrograde mobilization of the dominant pedicle, thus reducing the risk of iatrogenic damage. CT angiography could be a useful pre-operative study for the plastic surgeon when planning a gracilis flap, allowing better patient selection and providing a detailed description of the muscular and vascular structures of the thigh