Facial Artery Musculomucosal (Famm) Flap
H. O. B. TAYLOR
J. J. PRIBAZ
This is an excellent arterialized flap for reconstructions of the lower lip, particularly those including the vermilion. The donor site is usually quite acceptable, and there is no functional deficit. One should remember that wet mucosa transferred to the outside tends to dry and needs constant lubrication.
Refinements of previously used buccal mucosal flaps have led to the facial artery musculomucosal (FAMM) flap, which, through its axial pattern blood supply, oblique orientation, and high length-to-width ratio, provides a robust donor for the reconstruction of mucosal defects throughout the mouth and nose, with minimal donor-site morbidity With attention to detail, and inclusion of the facial artery along the full length of the flap, a long and narrow flap may be harvested in either a superiorly or inferiorly based manner, with few donor-site or flap complications.
Oral and perioral reconstruction requires the transfer of surrogate specialized tissues to reconstruct form and function. In the past, the buccal mucosa was utilized as a random musculomucosal flap (1, 2). The subsequent FAMM flap has been used in the reconstruction of a broad array of nasal and oral defects, including those in the palate, alveolus, nasal lining, maxillary antrum, tonsillar fossa, and floor of the mouth (3). It is particularly useful for reconstructing lip defects that may be too large to reconstruct with transfer of adjacent vermilion (4). The color, texture, and moisture of the mucosa carried by the FAMM flap combine to make it an excellent option for wet vermilion reconstruction. Although a number of other options exist for lip reconstruction, including mucosal grafts, labia minora grafts, two-stage flaps such as the tongue flap, cross-lip flap, bilateral island vermilion flaps, and free-tissue transfer (5), the FAMM flap provides a hardy source of axially perfused musculomucosal tissue in a single-stage procedure.
The FAMM flap is an axial buccal flap based on the facial artery, a branch of the external carotid system, which curves beneath the lower border of the mandible, at the anterior aspect of the masseter muscle. Passing in a serpentine fashion, upward toward the commissure, the facial artery lies deep to the risorius and zygomaticus major muscles, but superficial to the deepest perioral muscles, the buccinator, levator anguli oris, and the deep lamina of the orbicularis (Fig. 203.1A and B). Here it gives rise to multiple perforators of the cheek and continues superiorly toward the medial canthus of the ipsilateral eye as the angular artery. Anastomoses exist along its course with the buccal and infraorbital arteries. There is no named vein that drains this region, but a rich network to the anterior facial vein and posterior pterygoid plexus and internal maxillary vein provides a robust outflow. The position of the facial artery superficial to the buccinator requires that the FAMM flap include layers of mucosa, submucosa, and buccinator muscle in order to capture the vessel.