Anatomy of the postauricular island "revolving door" flap ("flip-flop" flap).

Reconstruction following resection of auricular (cavum conchae) lesions may be done with a retroauricular rotation flap. Recently there has been revived interest in this elegant reconstructive procedure. Although the vascular anatomy of the area was studied, no direct study of flap anatomy was reported. Six fresh adult male cadaveric dissections of the retroauricular area were performed. The skin and underlying subcutaneous tissue layer were reflected to correspond with flap size, and anatomic structures were studied. Dissection was carried out on 12 ears. The origin of the occipital belly of the occipitofrontalis muscle arising from the posterior mastoid region was identified in four patients and only as part of the fascial layer overlying the posterior mastoid region. Only a small portion of the sternocleidomastoid tendon at best is possibly incorporated in the flap. It seems that only a negligible contribution to the flap is derived from the temporalis muscle. The posterior auricular muscle was identified in all patients and its origin from the skull was (in all patients) included or bordered the posterior flap region. The posterior auricular artery (PAA) was seen in all 12 dissections. The artery was adjacent to the styloid process medial to the parotid gland superficially between the auricular cartilage and the mastoid process. The PAA was then found on the periosteum of the mastoid process, ascending deep to the posterior auricular muscle. The flap seems to be a truly fasciocutaneous flap with small, questionable, superior and anteroinferior muscular contributions, and an inclusion of the rather small posterior auricular muscle. As reported in other studies, blood supply to the area seems to be derived from the PAA.