Intravenous Infusion of Mesenchymal Stem Cells Promotes the Survival of Random Pattern Flaps in Rats.

BACKGROUND: Surgical reconstruction options of soft-tissue defects often include random pattern skin flaps. Flap survival depends on flap size and rotation arc and can be challenging regarding flap perfusion, leading to wound healing complications, insufficient wound coverage, and even flap loss. Therefore, novel approaches that promote skin flap survival are required. Bone marrow-derived mesenchymal stem cells intravenous infusion is therapeutically effective in various experimental disease models by means of multimodal and orchestrated mechanisms including anti-inflammatory and immunomodulatory effects, and by means of microvasculature reestablishment. METHODS: A modified McFarlane-type rodent skin flap model was used. After skin flap surgery, intravenous infusion of mesenchymal stem cells or vehicle was performed. In vivo optical near-infrared imaging using indocyanine green was performed, followed by histologic analysis, including hematoxylin and eosin and Masson trichrome staining, and gene expression analysis. RESULTS: The flap survival area was greater in the mesenchymal stem cell group. In vivo optical near-infrared perfusion imaging analysis suggested that skin blood perfusion was greater in the mesenchymal stem cell group. Ex vivo histologic analysis demonstrated that the skin structure was more clearly observed in the mesenchymal stem cell group. The dermal thickness was greater in the mesenchymal stem cell group, according to the Masson trichrome staining results. The authors observed a higher expression of fibroblast growth factor 2 mRNA in the tissues of the mesenchymal stem cell group using quantitative reverse-transcription polymerase chain reaction. CONCLUSION: These results suggest that intravenous infusion of bone marrow-derived mesenchymal stem cells promotes skin survival of random pattern flaps, which is associated with increased blood perfusion and higher expression of fibroblast growth factor 2.

Establishment of a Standardized Technique for Concha-type Microtia-How to Incorporate the Cartilage Frame into the Remnant Ear.

We have already reported surgical procedures for lobule-type microtia that provide an excellent contour and shape of the ear with minimum sacrifice of the donor. We have succeeded in establishing a standard surgical technique for almost all types of concha-type microtia that effectively uses the remnant ear and can use a unified costal cartilage frame. METHODS AND RESULTS: The concept of our technique is that remnant cartilage should be used maximally but that the deformed area should be completely replaced by the costal cartilage frame. The differences between the cartilage frame for lobule-type microtia and that for concha-type microtia are that the lower half beneath the antihelical area and the concha cymba in the base frame are omitted in concha-type microtia. The area from the tragus to the incisura of the tragus in the antihelical-tragal frame is also omitted. The area of the helical crus in the helical frame and the lower half in the antihelix are not immobilized in the base frame and are free edges. On the other hand, the remnant cartilage outside the concha is removed, but the antitragus is preserved. When the cartilage frame and the remnant are incorporated, all of the components of the ear can be provided. CONCLUSION: The ears created by our technique have a natural appearance and clear contour.