Vascularization of the long process of the malleus: surgical implications

Knowledge of the vascularization of the malleus may help to better understand some unwanted effects occurred in those surgical techniques using the handle as an attachment site of ossicle-replacement prostheses. Our hypothesis is that vascular damage occurred in the long process of the malleus during tympanic membrane detachment before fastening a malleovestibulopexy (MVP) prosthesis promotes the lysis of this ossicle at the attachment site. To confirm this premise, we carried out an evolutive and descriptive study of ten MVP procedures as well as a morphological analysis of ten cadaveric mallei using both light and scanning electron microscopies. The arterial supply of the manubrium comes from two main sources: vascular branches that reach this ossicle from the site of insertion of the tensor tympani tendon and small perforating branches which penetrate the bone from arteries of the tympanic membrane that, following the periosteum/perichondrium, they arrange parallel to the bone. The detachment of the tympanic membrane to fasten a MVP prosthesis causes a damage in the periosteal/perichondral vascular supply of the handle as well as micro-trauma on it, which can promote bone resorption at the point of anchorage by osteoclast stimulation. Respect periosteal vascularization of the manubrium may be important to prevent damage in this ossicle caused by some middle ear reconstruction prostheses.