Application of Various Methods to Evaluate the Postoperative Characteristics of Expanded Pedicled Deltopectoral Flap for Large Facial Scars.

ABSTRACT: The expanded pedicled deltopectoral flap (EPDF) has been widely used to repair large facial scars. Although doctors and patients are usually satisfied with the outcomes, the actual functional recovery and cosmetic effects of EPDF are still unknown. It is, therefore, necessary to objectively investigate the effect of transferred EPDF by using a variety of methods. From January 2008 to December 2018, 52 patients who underwent EPDF surgery at Xijing Hospital were enrolled. Sense of touch, static 2-point discrimination, elasticity, and color were measured. Thermesthesia and algesthesia were also tested. Postoperative scars were evaluated using the patient and observer scar assessment scale. Satisfaction of patients, doctors, and laypersons was investigated. The algaesthesis, thalposis, and rhigosis scores were 4.7 ±â€Š0.7, 3.7 ±â€Š0.9, and 4.5 ±â€Š0.8, respectively. The tactile score was 0.3 ±â€Š0.2 mN, and 2-point discrimination was 10.1 ±â€Š4.8 mm. L ∗ , a ∗ hemoglobin, and melanin content of the flaps were significantly different when compared with normal skin ( P   <  0.05). The satisfaction of doctors, patients, and laypersons was 88.5%, 71.2%, and 67.3%, respectively. The higher satisfaction of patients was mainly associated with the smaller color difference between the flap and the surrounding skin, and lower patient and observer scar assessment scale score. These results confirm that excellent functional recovery and reliable cosmetic effects are observed when facial scars are repaired with EPDF. The methods used in this study can be applied to the evaluation of functional recovery and cosmetic outcomes of transferred flaps, which may provide a more comprehensive understanding of flap assessment.

Secreted PEDF modulates fibroblast collagen synthesis through M1 macrophage polarization under expanded condition.

Tissue expansion is widely used to obtain new skin tissue for repairing defects in the clinical practice of plastic surgery. One major complication can be dermal thinning during expansion, which usually leads to skin rupture. Collagen synthesis can determine dermal thickness and can be influenced by macrophage polarization during expansion. The aim of the study was to test whether pigment epithelium-derived factor (PEDF) could be a modulator of collagen synthesis in fibroblasts by regulating macrophage polarization during skin expansion. Our results showed that PEDF mRNA expression was increased in expanded human and mouse epidermis. PEDF protein levels were elevated in the subcutaneous exudates of a rat skin expansion model. Increased PEDF mRNA expression was accompanied by dermal thinning during a three-week expansion protocol. Subcutaneous injection of PEDF in vivo further resulted in dermal thinning and cell number increase of M1 macrophage in the expanded skin. PEDF also promoted macrophage polarization in vitro to the M1 subtype under hypoxic conditions. PEDF did not influence collagen gene expression in fibroblasts directly, but attenuated collagen synthesis in a macrophage-mediated manner. Additionally, blockage of PEDF receptors on macrophages with inhibitors rescued collagen synthesis in fibroblasts. Our research demonstrated PEDF elevation in expanded skin leads to dermal thinning through M1 macrophage-mediated collagen synthesis inhibition in fibroblasts. Our results could form a basis for the development of novel strategies to improve skin integrity in expanded skin by using PEDF.

Comparison of 1565-nm Nonablative Fractional Laser and 10600-nm Ablative Fractional Laser in the Treatment of Mild to Moderate Atrophic Acne Scars.

BACKGROUND: The 10,600-nm ablative fractional laser (AFL) is widely used for treating facial atrophic acne scars but with evident side effects. By contrast, the common Er:Glass non-AFL (NAFL) is safer but lacks of comparable outcomes. A novel 1,565 nm Er:Glass NAFL improves thermal energy delivery and could yield better outcomes. OBJECTIVE: We aimed to compare the effectiveness and safety between the 1,565-nm NAFL and 10,600-nm AFL in treating mild-to-moderate facial atrophic acne scars. METHODS: Nineteen patients with mild-to-moderate bilateral facial atrophic acne scars were enrolled in a randomized split-face trial, which involved 3-session procedures for each laser. The effectiveness and safety were evaluated by doctors and patients who were blinded to the treatment assignment. RESULTS: Both lasers improved the acne scar profiles comparably. A marked reduction in erythema, crusting durations, and degree of pain were noted on the sides treated with the 1,565-nm NAFL, relative to those treated with the 10,600-nm AFL. CONCLUSION: Both 1,565 nm-NAFL and 10,600-nm AFL can improve mild-to-moderate acne scars. Patients should never expect complete resolution. The 1,565-nm NAFL has less side effects.

Hair follicle bulge-derived stem cells promote tissue regeneration during skin expansion.

Skin expansion is widely used in reconstructive surgery to obtain supplemental and optimal skin. Enhancing the regenerative capacity of expanded skin is therefore of great interest. Hair follicle bulge-derived stem cells (HFBSCs) located in hair follicle bulges are closely associated with skin; HFBSC transplantation could promote cutaneous wound repair. However, the effects of transplanted HFBSCs on skin regeneration during expansion remain unclear. The aim of the study was to reveal the potential effects of transplanted HFBSCs in the expanded skin and explore its mechanism. Our results showed higher skin area, tissue weight, epidermal thickness, dermal thickness, proliferating cell count, collagen content, microcirculatory blood flow, blood vessels, and lower retraction ratios were observed in HFBSC-injected rats compared to uninjected controls. Moreover, the transplanted HFBSCs directly contributed to tissue regeneration by differentiating into vascular endothelial cells, epidermal cells, and the outer root sheath cells of hair follicle. Higher expression of EGF, VEGF, bFGF, and TGF-ß were observed in HFBSC-injected rats. Our research demonstrated the transplanted HFBSCs could promote skin regeneration by differentiating into various types of skin related cells and by up-regulating the expression of growth factors. Our results could form a basis for the development of novel strategies to enhance regeneration in expanded skin by using HFBSCs.

Establishment of a Novel Mouse Model for Soft Tissue Expansion.

BACKGROUND: Despite its increasing use, not much is known about tissue expansion, and its complication rates are significantly high. Thus, there is an urgent need to establish a stable animal model to overcome the limitations and complications of tissue expansion. Although the mouse model has shown several advantages in the in-depth studies, an appropriate mouse expansion model has rarely been reported, likely because of its loose skin. MATERIALS AND METHODS: A micro expander was designed and implanted under the scalp of a mouse (expanded group); sterilized saline was regularly injected into the expander. In sham-operated mice (control group), a silicone sheet was implanted under the scalp. Skin samples were collected 5 wk after surgery. Histologic changes including epidermal and dermal thickness and collagen fiber arrangement were analyzed. In addition, vascular density and cell proliferation ratio were determined. An ultrastructural analysis was also performed. RESULTS: With the application of the expansion device, the skin became tight and showed area enlargement. The epidermal thickness of the expanded skin increased significantly (P < 0.01), whereas the thickness of the dermis decreased significantly (P < 0.05) as compared with the control skin. Masson staining demonstrated that collagen bundles were arranged more compactly in the expanded skin (P < 0.05) than in the controls. Furthermore, more proliferating cells (P < 0.05) and blood vessels (P < 0.01) were observed. Transmission electron microscopy showed that the fibers of expanded skin were stretched and broken into bundles of various diameters, with abundant active fibroblasts. CONCLUSIONS: A reliable mouse model of scalp skin expansion was successfully established, which may be a promising tool for in-depth studies on skin soft tissue expansion.