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Background In full-thickness nasal defects, the internal lining is perhaps the most challenging aspect of the three layers to rebuild. Nasal damage is usually more concentrated on the tip, soft triangles, alar wings, and columella, but the lateral nasal arteries are often left intact and the damage to the dorsal sidewalls are normally superficial. Methods Twelve patients who required total nasal reconstruction received a forehead flap placement as external coverage and autologous rib cartilage as structural support. Residual normal/superficial scar tissue flaps on the dorsal sidewalls with lateral nasal artery pedicles were mobilized and designed for internal lining repair without creating secondary donor site damage. The flaps were then turned 180° downward and placed between the alar medial angles and the fornix. Results No total lining flap necrosis occurred in all the patients. Partial necrosis occurred on the distal edge owing to overpressure of the nostril splint to the flaps; however, the wounds eventually healed, and the nasal structural integrity was preserved. The patients were satisfied with the aesthetic results and had no complaints of airway stenosis. Conclusions Lateral nasal artery pedicle dorsal sidewall skin flaps are appropriately thick, providing enough nostril circumferential support to improve airway stenosis. It allows sufficient blood supply and creates no extra donor site damage. Blood vessels and skin flaps are often undamaged, thereby allowing maximum application in total nasal reconstruction.

Clinical application of mechanical stretching is a reconstructive method for skin repair. Although studies have reported dermal fibroblast heterogeneity, whether stretching affects individual fibroblast subpopulations equally remains unclear. In this study, we show the changes in dermal structure and papillary fibroblast (Fp) in regenerated human skin. Exhausted skin regeneration caused dermal‒epidermal junction flattening, papillary dermis thinning, and an increase in type III collagen-to-type I collagen ratio, with upregulated hallmarks of aging. Well-regenerated skin displayed a notable increase in the Fp population. Consistent changes were observed in the rat expansion model. Moreover, we found that TGFβ1 expression was especially increased in skin showing good regeneration. Activation of the TGFβ1/SMAD2/3 pathway improved exhausted skin regeneration and resulted in increased collagen content and Fp proliferation, whereas pharmacological inhibition of TGFβ1 action impacted well-regenerated skin. Short-term mechanical stretching that promoted skin regeneration enhanced Fp proliferation, extracellular matrix synthesis, and increased TGFβ1 expression, leading to good regeneration. Conversely, long-term stretching induced premature Fp senescence, leading to poor regeneration. This work shows the mechanism of mechanical stretching in well-skin regeneration that enhances Fp proliferation and extracellular matrix synthesis through the TGFβ1/SMAD2/3 pathway and highlights a crucial role of Fps in stretching-induced skin regeneration.

Background Mechanical stretch, in term of skin expansion, can induce effective but limited in vivo skin regeneration for complex skin defect reconstruction. We propose a strategy to obtain regenerated skin by combining autologous stem cell transplantation with mechanical stretch. Methods This randomized, blinded placebo-controlled trial enrolled 38 adult patients undergoing skin expansion presenting with signs of exhausted regenerative capacity. Patients randomly received autologous bone marrow mononuclear cell (MNC) or placebo injections intradermally. Follow-up examinations were at 4, 8 weeks and 2 years. The primary endpoint was the volume achieved in relation to the designed size of the expander (expansion index, EI). Secondary endpoints were surface area, thickness and texture of expanded skin. This trial is registered with ClinicalTrial.gov, NCT01209611. Findings The MNC group had a significantly higher EI at 4 weeks (mean difference 0.59 [95% CI, 0.03–1.16]; p = 0.039) and 8 weeks (1.05 [95% CI, 0.45–1.66]; p = 0.001) versus controls. At 8 weeks, the MNC group had significantly thicker skin (epidermis: p, Highlights • This study shows that intradermally transplanted MNCs in mechanical stretched skin is a safe and feasible clinical application. • Intradermally transplantation of MNCs can overcome the regenerative limitations of skin. • The strategy of combining stem cell and microenvironment can provide significant amounts tissue for surgical reconstruction. Though stem cells are proved to participate in tissue regeneration, there is seldom clinical research combining stem cell and in vivo mechanotransduction to provoke skin regeneration. In this study, we introduce autologous bone marrow stem cells to mechanical stretch induced skin regeneration. The results showed that the potential of autologous stem cells in promoting skin regeneration. The application of stem cell assisted skin expansion can overcome the regenerative limitations of skin to provide significant amounts tissue for surgical reconstruction. The integration of stem cells and mechanical stretch stimuli will engender further advances in in vivo tissue regeneration.

Background Supraclavicular flaps had been widely used as pedicled flaps to reconstruct face and neck defects. However, the size of this traditional flap was limited even after expansion. In this study, we present a flap pedicled by the thoracic branch of supraclavicular artery (TBSA). The flap is located at the subclavicular region, and has the advantage of large dimension, matching colour and thin thickness. Methods In this series, 24 patients with ages ranging between 3 and 49 years (30 flaps with six patients in bilateral fashion) were treated in the authors’ institution. Results The maximum size of the flap was 25 cm × 25 cm, whereas the minimum size was 15 cm × 10 cm. The average size of the flaps was 241.1 ± 95.7 cm2. Twenty-six flaps (86.7%) survived completely. Total flap loss was seen in one patient (3.3%) and was treated with reverse harvesting skin graft. Partial flap necrosis occurred in three flaps (10.0%). Through a mean time of 10-month follow-up, the colour and the texture of the flaps matched with the recipient area. No conspicuous flap contracture was observed. Conclusion This expanded subclavicular flap pedicled by the TBSA has proved to be a promising method with satisfactory outcome and high success rate.