Cyclic High Negative-Pressure External Volume Expansion Reduces Daily Device Application Time With Similar Effects on Recipient Site Preparation in a Murine Model

Introduction: Recipient site preparation using external volume expansion (EVE) increases graft survival in large-volume fat grafting. To improve patient compliance with using the device, we tested a new cyclic high negative-pressure (CHNP) mode that involves 1 h/day at -55 mm Hg, cycled between 1-second negative-pressure activation, followed by a 2-second deactivation period in an animal model. Material and Method: A miniaturized EVE device was applied to 30 8-week-old male Sprague-Dawley rats. The rats were assigned to 3 groups (no pressure for the control group, conventional -25 mm Hg for 8 h/day for conventional EVE, and CHNP mode for the CHNP group). After 28 days, micro-computed tomography was performed and skin biopsy specimens were obtained. Results: The CHNP group showed a 6.6-fold increase and the conventional EVE group showed a 4.4-fold increase in volume compared to the control group. Hematoxylin and eosin staining showed a similar increase in subcutaneous tissue thickness in both EVE groups, compared to the control group. Masson's trichome and proliferating cell nuclear antigen staining showed significantly higher collagen deposition and subdermal adipocytes in EVE groups. Immunohistochemistry against platelet endothelial cell adhesion molecule 1 showed 2.5- and 2.7-times higher vessel density in the conventional and CHNP EVE groups, respectively. There was no statistically significant difference in subcutaneous tissue thickness, collagen deposition, subdermal adipocyte proliferation, and vessel density between the 2 EVE groups. Conclusion: CHNP produced comparable results in recipient site preparation (subcutaneous tissue thickening and angiogenesis) compared to the conventional protocol, while markedly reducing the daily wear-time from 8 hours to 1 hour. Although further clinical data must be acquired, our new pressure setting seems promising and provides a more patient-friendly pre-expansion environment.

Effect of Silicone Patch Containing Metal-organic Framework on Hypertrophic Scar Suppression

BACKGROUND/AIM

Hypertrophic scars (HS) are an abnormal cutaneous condition of wound healing characterized by excessive fibrosis and disrupted collagen deposition. This study assessed the potential of a silicone patch embedded with chemically stable zirconium-based metal-organic frameworks (MOF)-808 structures to mitigate HS formation using a rabbit ear model.

MATERIALS AND METHODS

A silicone patch was strategically engineered by incorporating Zr-MOF-808, a composite structure comprising metal ions and organic ligands. Structural integrity of the Zr-MOF-808 silicone patch was validated using scanning electron microscopy and X-ray diffraction analysis. The animals were divided into three groups: a control, no treatment group (Group 1), a silicone patch treatment group (Group 2), and a group treated with a 0.2% loaded Zr-MOF-808 silicone patch (Group 3). HS suppression effects were quantified using scar elevation index (SEI), dorsal skin thickness measurements, and myofibroblast protein expression.

RESULTS

Histopathological examination of post-treatment HS samples revealed substantial reductions in SEI (34.6%) and epidermal thickness (49.5%) in Group 3. Scar hyperplasia was significantly diminished by 53.5% (p<0.05), while collagen density declined by 15.7% in Group 3 compared to Group 1. Western blot analysis of protein markers, including TGF-β1, collagen-1, and α-SMA, exhibited diminished levels by 8.8%, 12%, and 21.3%, respectively, in Group 3, and substantially higher levels by 21.9%, 27%, and 39.9%, respectively, in Group 2. On the 35th day post-wound generation, Zr-MOF-808-treated models exhibited smoother, less conspicuous, and flatter scars.

CONCLUSION

Zr-MOF-808-loaded silicone patch reduced HS formation in rabbit ear models by inducing the proliferation and remodeling of the wound healing process.

Nasal Osteotomies Revisited in Asians: Surface Aesthetics, Anatomical and Technical Considerations

Background  Although osteotomy is commonly performed in rhinoplasty, it is difficult for less experienced surgeon to understand mechanism of the procedure. The primary goal of this study is to improve understanding of nasal osteotomy in Asians by considering the surface aesthetics and anatomy of the nose as well as their relationships with the surgical procedure. Methods  Surface aesthetics, anatomic considerations, kinetics of medial and lateral osteotomy, fracture levels of osteotomy were discussed in detail by reviewing the previous publications and 18 years of our experience. Moreover, the technical details of osteotomy were explained and personal tips for performing successful osteotomy were described. Results  Dorsal and lateral aesthetic lines, dorsal and basal widths are main characteristics related to the surface aesthetics of nose to perform the osteotomy. In addition, these features are different in Asian population due to the anatomic difference with Caucasians, which makes the procedure difficult and requires more attention to perform osteotomy. Conclusion  Because osteotomy is one of the most traumatic and invasive part of the rhinoplasty, it is crucial for the rhinoplasty surgeon to understand the relationship between surface aesthetics and osteotomy techniques to produce consistent and reproducible results.

Nipple Projection Change in Immediate Breast Reconstruction and Use of an Acellular Dermal Matrix Strut for Maintaining Nipple Projection

BACKGROUND

Nipple-sparing mastectomy (NSM) has gained popularity as more studies have supported its oncologic safety. Although there have been some studies reporting complications including mastectomy flap and nipple necrosis, there have been few reports discussing the change in nipple projection following NSM. This study aimed to analyze the change in nipple projection after NSM and identify risk factors for nipple depression. In addition, the authors present a new method for maintaining nipple projection.

METHODS

Patients who underwent NSM between March of 2017 and December of 2020 at the authors' institute were included in this study. The authors measured the preoperative and postoperative nipple projection height and used a nipple projection ratio (NPR) to compare the change in height. Univariate and multivariate analyses were performed to examine the correlation of variables with the NPR.

RESULTS

A total of 307 patients and 330 breasts were included in this study. There were 13 cases of nipple necrosis. The postoperative nipple height was decreased by 32.8%, which was statistically significant. In multiple linear regression analysis, the use of an acellular dermal matrix strut was positively correlated with the NPR and implant-based reconstruction and postmastectomy radiation therapy were negatively correlated with the NPR.

CONCLUSIONS

The results of this study demonstrated that the reduction in nipple height after NSM was statistically significant. Surgeons need to be aware of these changes following NSM and explain this possibility to patients who have risk factors. The application of an acellular dermal matrix strut should be considered for the prevention of nipple reduction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Improving Facial Fat Graft Survival Using Stromal Vascular Fraction-Enriched Lipotransfer: A Prospective Multicenter, Randomized Controlled Study

BACKGROUND

Although previous clinical studies have reported that cell-assisted lipotransfer increases the fat survival rate in facial fat transplants, most were case studies without quantitative evaluation. A multi-center, prospective, randomized, controlled study was performed to evaluate the safety and efficacy of the stromal vascular fraction (SVF) in facial fat grafts.

METHODS

Twenty-three participants were enrolled for autologous fat transfer in the face, and randomly assigned to the experimental ( n =11) and control ( n =12) groups. Fat survival was assessed using magnetic resonance imaging at 6 and 24 weeks postoperatively. Subjective evaluations were performed by the patients and surgeons. To address safety concerns, results of an SVF culture and the postoperative complications were recorded.

RESULTS

The overall fat survival rate was significantly higher in the experimental group than in the control group (6 weeks: 74.5±9.99% vs. 66.55±13.77%, p <0.025; 24 weeks: 71.27±10.43% vs. 61.98±13.46%, p <0.012). Specifically, graft survival in the forehead was 12.82% higher in the experimental group when compared with that in the control group at 6 weeks ( p <0.023). Furthermore, graft survival in the forehead ( p <0.021) and cheeks ( p <0.035) was superior in the experimental group at 24 weeks. At 24 weeks, the aesthetic scores given by the surgeons were higher in the experimental group than in the control group ( p <0.03); however, no significant intergroup differences were noted in the patient-evaluated scores. Neither bacterial growth from SVF cultures nor postoperative complications were noted.

CONCLUSIONS

SVF enrichment for autologous fat grafting can be a safe and effective technique for increasing the fat retention rate.

Conventional versus modified nipple sparing mastectomy in immediate breast reconstruction: Complications, aesthetic, and patient-reported outcomes

Background

Nipple-sparing mastectomy (NSM) followed by immediate breast reconstruction (IBR) is the optimal surgical treatment for breast cancer. However, investigations are ongoing to improve the surgical technique to achieve better results. This study aimed to evaluate the outcomes of modified NSM (m-NSM), which preserves the anterior lamellar fat layer, in patients who underwent IBR.

Methods

All patients who underwent modified NSM (m-NSM) or conventional NSM (c-NSM) followed by IBR using autologous tissue or implants were retrospectively reviewed between January 2014 and January 2021. Two mastectomy types were compared in terms of postoperative complications and aesthetic outcomes using panel assessment scores by physicians and reported outcomes using Breast-Q. In addition, postoperative evaluations of the thickness of mastectomy flap was performed using CT scan images.

Results

A total of 516 patients (580 breasts) with NSM (143 breasts with c-NSM and 437 breasts with m-NSM) followed by IBR were reviewed. The mean ± SD flap thickness was 8.48 ± 1.81 mm in patients who underwent m-NSM, while it was 6.32 ± 1.15 mm in the c-NSM cohort (p = 0.02). The overall major complications rate was lower in the m-NSM group (3.0% vs. 9.0%, p < 0.013). Ischemic complications of the mastectomy flap and nipple-areolar complex (NAC) were more in c-NSM, although the difference was not statistically significant. The mean panel assessment scores were higher in the m-NSM group (3.14 (good) and 2.38 (fair) in the m-NSM and c-NSM groups, respectively; p < 0.001). Moreover, m-NSM was associated with greater improvements in psychosocial (p < 0.001) and sexual (p = 0.007) well-being.

Conclusion

Preserving the anterior lamellar fat in NSM was associated with thicker mastectomy flap, overall lower rates of complications, including ischemia of the mastectomy flap and nipple-areolar complex, and was associated with better aesthetic outcomes and improved quality of life.

Risk factors for chest wall depression after implant insertion for breast reconstruction: a retrospective quantitative study

Background

Methods

Results

Conclusions