Morphological Changes and Durability of Skin and Mucosal Flaps in Intraoral and Pharyngeal Reconstructions: Long-term Follow-up and Literature Review for Potential Second Carcinomas

The long-term changes in tissues implanted in the oral cavity and pharynx after head and neck reconstruction have not been fully evaluated. This study aimed to clarify the morphological changes, long-term durability, and potential for secondary carcinogenesis in such tissues. In our single-center study, the rough morphological changes in 54 cases of intraoral and pharyngeal skin and mucosal flaps were evaluated more than 10 years after flap transfer. In addition, the literature on the development of second carcinomas from skin flaps was reviewed. The mean follow-up period for transferred flaps was 148 months. The reconstruction areas and the probability of morphological changes were significantly correlated (p=0.006), especially in cases with tongue, lower gingiva, and buccal mucosal reconstruction. Free jejunal flap surfaces were well maintained, whereas tubed skin flaps showed severe morphological changes in cases with pharyngeal reconstruction. None of the flaps in our series developed second primary carcinomas. Skin flaps generally had good durability for > 10 years in intraoral environments, while mucosal flaps had better durability for pharyngeal reconstruction. Second squamous carcinomas arising from skin flaps are extremely rare; however, surgeons should take this possibility into consideration and conduct meticulous and long-term follow-up.