Vascular Nature and Existence of Anastomoses of Extrinsic Postauricular Fascia: Application for Staged Auricular Reconstruction

Abstract: A staged auricular reconstruction in microtia patients was developed by using superficial mastoid fascia (as part of extrinsic postauricular fascia) to cover the cartilagenous framework due to its highly vascularized nature. Three branches of external carotid artery (superficial temporal artery, posterior auricular artery and occipital artery) were found to supply this fascia, this study was therefore aimed to investigate the dimension of blood supply from each vessel and also to demonstrate the existence of anastomoses among these arteries. Thirty-eight pinnas and postauricular fascias from Thai fresh adult cadavers were included to document the anastomoses by showing both perfused dye connection (10 dissections) and visible anastomotic branches (8 dissections) among them. Distribution of each vessel trunk and its branches were demonstrated using superimposed illustration in the other 20 dissections with dye injection into each artery to designate 3 zones of anastomotic area between each arterial pair. Maximal size of viable postauricular fascial flap for staged reconstruction according to this vascular study was thus estimated to be at least 5 cm above and 3 cm below the Frankfurt horizontal plane and about 6 cm posterior to external acoustic meatus owing to the course of posterior auricular artery and its anastomoses. In addition, greater size of flap with dual blood supply from both superficial temporal and posterior auricular arteries can be raised by harvesting beyond 5 cm above external acoustic meatus.

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