Recent Advances on the Application of Negative Pressure External Volume Expansion in Breast Plastic Surgery

Mechanism of Origin of Positive Tissue Pressure During Negative-Pressure Wound Therapy

This report provides a simplified insight into the previously unexplained physical mechanism of the origin of local positive tissue pressure during negative-pressure wound therapy (NPWT). A chain of 2 spring model could be used to show the biomechanical interaction between the NPWT dressing and the adjacent body tissues. It is important to assume that the application of NPWT dressing to the body surface creates a new closed compartmentalized volume. Air suction generates local positive pressure within the dressing due to unopposed atmospheric load, which in turn leads to compression of the adjacent tissues and induction of positive pressure there. Analysis of the biomechanical events during NPWT implies the possibility of tissue injury by positive pressure and suggests clinical alertness in regard to the balance between the size of the NPWT dressing and suction pressure as well as further related research.

Efficacy of breast augmentation using an external breast tissue expander for a shorter period while applying higher pressure: a preliminary study

Background Various types of external breast tissue expanders have been found to be effective for aesthetic breast augmentation. However, their use has been limited when compared with implant-based breast augmentation due to the burdensome nature of their application. This article reports the possibility that external breast tissue expanders may be applied safely and effectively with higher pressure and shorter application time.Methods The participants comprised patients who desired breast augmentation using the EVERA-RAPHA device between January 2020 and March 2020. A double-blinded prospective study was conducted on two groups of eight patients each, with either 60 mmHg or 100 mmHg of pressure applied. Standardized photographs were taken and blinded measurements of volume and circumference were made. The Mann-Whitney and paired t-tests were conducted.Results Sixteen patients were evaluated after 1 month of treatment. The women in groups 1 and 2 (60 mmHg and 100 mmHg, respectively) used EVERA-RAPHA for 15.400± 0.704 and 15.300±0.477 minutes per day, respectively. The mean volume increases in groups 1 and 2 were 39.000±42.526 cc and 27.700±20.260 cc, respectively. No patients dropped out of the study. All patients reported that the device was tolerable. Mild bruising was found in 62.5% of the patients in group 2.Conclusions Breast augmentation using external tissue expanders can be a safe, effective, and practical option. Pressures of 60 mmHg or 100 mmHg can be safely applied for a shorter duration. Larger studies are needed to further confirm our findings.

To use indwelling drainage or not in dual-plane breast augmentation mammoplasty patients: A comparative study

To explore the necessity of indwelling drainage in dual-plane breast augmentation mammoplasty patients.Female patients (123 in total) were selected from June 2015 to June 2018 in the Department of Plastic Surgery at Peking Union Medical College Hospital and were randomly divided into 2 different groups: the with drainage group (WD group, 57 patients) and the without drainage group (WOD group, 66 patients). In the 2 groups, the operation time, postoperative stay, and hospitalization expenses were recorded. The BREAST-Q Version 2.0 Augmentation Module Pre- and Postoperative Scales (Chinese Version) were used to evaluate psychosocial well-being, sexual well-being, physical well-being, and satisfaction with breasts preoperatively and postoperatively (1 year after operation).Before the operation, no significant differences were found in psychosocial well-being, sexual well-being, physical well-being, or satisfaction with breasts between these 2 groups. In the WOD group, postoperative stay and hospitalization expenses were remarkably decreased, but the operation time was similar, compared with the WD group. Compared with before the operation, both groups had significantly increased scores in psychosocial well-being, sexual well-being, and satisfaction with breasts after the operation. However, no significant differences were found between the 2 groups. No complications were found in any of the patients.Although the operation time was not significantly decreased, patients without drainage could save much more time and money and simultaneously reach similar postoperative effects in psychosocial well-being, sexual well-being, physical well-being, and satisfaction with breasts. Therefore, drainage may not be necessary in patients who undergo dual-plane breast augmentation mammoplasty.

Negative Pressure From an Internal Spiral Tissue Expander Generates New Subcutaneous Adipose Tissue in an In Vivo Animal Model

BACKGROUND

Tissue expanders are widely utilized in plastic surgery. Traditional expanders usually are "inflatable balloons," which are planned to grow additional skin and/or to create space to be filled, for example, with an implant. In very recent years, reports suggest that negative pressure created by an external device (ie, Brava) induces both skin expansion and adipogenesis.

OBJECTIVES

The authors evaluated and assessed the adipogenetic potential of a novel internal tissue expander in an in vivo animal model.

METHODS

New Zealand female rabbits were enrolled in the study. A prototype spiral inner tissue expander was employed. It consisted of a-dynamic conic expander (DCE) with a valve at the end: when empty, it is flat (Archimedean spiral), whereas when filled with a fluid, it takes a conic shape. Inside the conic spiral, a negative pressure is therefore created. DCE is implanted flat under the latissimus dorsi muscle in experimental animals (rabbit) and then filled to reach the conical shape. Animals were investigated with magnetic resonance imaging, histology, and transmission electronic microscopy at 3, 6, and 12 months.

RESULTS

Magnetic resonance imaging revealed a marked increase in newly formed adipose tissue, reaching its highest amount at 12 months after the DCE implantation. Histology confirmed the existence of new adipocytes, whereas transmission electronic microscopy ultrastructure confirmed that most of these new cells were mature adipocytes.

CONCLUSIONS

Tensile stress, associated with negative-pressure expanders, generated newly white subcutaneous adipose tissue.

Increase of glandular epithelial cell clusters by an external volume expansion device promotes adipose tissue regeneration by recruiting macrophages

Background: There is a clinical need for the use of engineered adipose tissue in place of surgical reconstruction. We previously found that the external volume expansion (EVE) device increased special cell clusters in well-vascularized connective stroma during adipose regeneration. However, the origin of these cell clusters and their role in adipose tissue regeneration remain unknown. Aim: In the present study, we evaluated EVE in the construction of expanded prefabricated adipose tissue (EPAT) in a rat model. Methods: Rats were randomized into an EVE suction group and a control group, with 24 rats in each group. The structure and origin of the special cell clusters were determined by hematoxylin and eosin staining, and immunohistochemistry; their role in adipose tissue regeneration was investigated by immunohistochemistry and Western blot analyses. Results: Special cell clusters began to increase at week 1 with a peak at week 4, and then receded from weeks 8 to 12. Clusters were identified as glandular epithelial cells as determined by their gland-like structure and expression of specific markers. The cell clusters induced significant infiltration of macrophage antigen-2 (Mac-2) positive macrophages by secreting monocyte chemoattractant protein-1 (MCP-1) at the early stage of suction. Subsequently, these infiltrated macrophages expressed massive vascular endothelial growth factor (VEGF) to promoted angiogenesis. Conclusion: EVE generated glandular epithelial cell clusters, which recruited macrophages to promote angiogenesis and subsequent adipose tissue regeneration. These findings shed light on the mechanisms underlying the effects of EVE devices on adipose tissue regeneration.