大胸筋皮弁の血行形態に関する研究

Abstract

The pectoralis major musculocutaneous flap (PMMC-flap) has been used for the immediate reconstruction of defects in thc head and neck region. This technique is highly valued because it can transplant a large amount of well-vascularized tissue, but its vascular pattern seems to have been characterized by a simple axial pattern without adequate investigation.Recently, the vascular anatomy has been clarified gradually as many authors have reported on it in detail. The purpose of this study was to define the vascular pattern of the PMMCflap by dye injection, angiography and cadaver dissection.Materials and methods:Dye injection: Fresh cadavers (3 males, 2 females), were used and different color inks were injected in to the internal thoracic artery and thoracoacrominal artery. Then the colored skin areas on the chest were observed and recorded. Angiography: Fresh cadavers (3 males, 7 females) were also used into which a contrast medium was infused via the femoral artery, and the pectoralis major muscle and overlying skin with adjacent vessels were resected. After taking X-ray photographs and making the angiograms, the vascular patterns in the muscle and cutaneous layer were analysed. Subsequently the PMMC-flap on the cadavers was evaluated and the vascular pattern was analysed from the angiograms.Cadaver dissection: The vascular anatomy was studied by cadaver dissection.Results:1) The pectoralis major muscle and the overlying skin were found to receive their blood supply from separate blood vessels.2) The musculocutaneous perforators directly airisng from the dominant artery appeared in certain limited areas only and not observed in the area where the skin island is usually designed.3) The blood supply of the PMMC-flap was supported by a communicating circulatory system from the muscle to cutaneous layer, which was formed by the pectoral branch anastomosing with the anterior perforators in the muscle and fascial layer.4) It seems that the vascular pattern of the PMMC-flap is not of axial pattern directly sustained by musculocutaneous perforators arising from the pectoral branch but is of extended axial pattern which is spreaded in three dimensions by anastomosis to adjacent vessels.5) The concept of this vascular pattern is very important and the author thinks that with this knowledge we can reduce the risk of partial and/or marginal necrosis in the skin island on the PMMC-flap.