BackgroundPartially resecting ribs of the recipient site to facilitate easy anastomosis of the internal mammary vessels to free flaps during breast reconstruction can cause chest wall pain or deformities. To avoid this, the intercostal perforating branches of the internal mammary vessels can be used for anastomosis. The purpose of this study was to investigate the location and size of the internal mammary perforator vessels based on clinical intraoperative findings and to determine their reliability as recipient vessels for breast reconstruction with microsurgical free tissue transfer.MethodsTwelve patients were preoperatively screened for the presence of internal mammary perforators using Doppler tracing. After modified radical mastectomy was performed by a general surgeon, the location and size of the internal mammary perforator vessels were microscopically investigated. The external diameter was examined using a vessel-measuring gauge from a mechanical coupling device, and the distance from the mid-sternal line to the perforator was also measured.ResultsThe largest arterial perforator averaged 1.5 mm, and the largest venous perforator averaged 2.2 mm. Perforators emerging from the second intercostal space had the largest average external diameter; the second intercostal space also had the largest number of perforators arising from it. The average distance from the mid-sternal line to the perforator was 20.2 mm.ConclusionsInternal mammary perforators presented consistent and reliable anatomy in this study. Based on these results, the internal mammary perforators appear to have a suitable diameter for microvascular anastomosis and should be considered as an alternative recipient vessel to the internal mammary vessel.

Soft tissue augmentation is a process of implanting tissues or materials to treat wrinkles or soft tissue defects in the body. Over the years, various materials have evolved to correct soft tissue defects, including a number of tissues and polymers. Autogenous dermis, autogenous fat, autogenous dermis-fat, allogenic dermis, synthetic implants, and fillers have been widely accepted for soft tissue augmentations. Tissue engineering technology has also been introduced and opened a new venue of opportunities in this field. In particular, a long-lasting filler consisting of hyaluronic acid filler and living human mesenchymal cells called "injectable tissue-engineered soft tissue" has been created and applied clinically, as this strategy has many advantages over conventional methods. Fibroblasts and adipose-derived stromal vascular fraction cells can be clinically used as injectable tissue-engineered soft tissue at present. In this review, information on the soft tissue augmentation method using the injectable tissue-engineered soft tissue is provided.Graphical Abstract

A new injectable tissue-engineered soft tissue consisting of a mixture of hyaluronic acid (HA) filler and cultured human fibroblasts have been developed by the authors. To establish this method as a standard treatment, a further study was required to determine whether the injected fibroblasts could stay at the injected place or move to other sites. In addition, effective strategies were needed to increase viability of the injected fibroblasts. The purpose of this study was to track the injected fibroblasts and to determine the effect of adding prostaglandin E1 (PGE1) or vitamin C on the viability of fibroblasts.Human fibroblasts labeled with fluorescence dye were suspended in HA filler and injected into 4 sites on the back of nude mice. The injected bioimplants consisted of one of the 4 followings: HA filler without cells (HA group), fibroblasts suspended in HA filler (HA þ FB group), PGE1-supplemented fibroblasts in HA filler (HA þ FB þ PGE1 group), and vitamin C-supplemented fibroblasts in HA filler (HA þ FB þ VC group). At 4 weeks after injection, locations and intensities of the fluorescence signals were evaluated using a live imaging system.The fluorescence signals of the fibroblast-containing groups were visible only at the injected sites without dispersing to other sites. The HA þFB þ PGE1 group showed a significantly higher fluorescence signal than the HA þ FB and the HA þ FB þVC groups (P < 0.05, each). There was no statistical difference between the HA þ FB and HA þ FB þVC groups (P ¼ 0.69).The results of the current study collectively suggest that injected fibroblasts suspended in HA filler stay at the injected place without moving to other sites. In addition, PGE1 treatment may increase the remaining rhodamine B isothiocynanate dye at the injected site of the human dermal fibroblasts.F or correction of facial wrinkles or soft-tissue augmentation, a number of commercially prepared injectable fillers have been developed. 1-4 Currently, soft-tissue filler products based on hyaluronic acid (HA) are widely used, because they have a low potential for allergic reactions, require no skin testing, can be stored at room temperature, and have no risk of bovine spongiform encephalopathy unlike collagen. Although HA fillers have shown to be relatively safe and convenient to administrate, their variable degrees of resorption require repeated injections. To overcome these drawbacks, the authors created a new injectable filler consisting of a mixture of HA filler and living cultured human fibroblasts. 5,6 The results of our previous experimental and clinical studies showed that cultured human dermal fibroblasts mixed into HA filler can produce human dermal matrices with extended in vivo stability and may have a potential to be used as a long-lasting injectable soft-tissue filler. To establish this method as a standard treatment, a further study, however, is required to determine whether the fibroblasts could stay at the injected place or move to other sites through examination of the location, distribution, and long-...