Comparative Analysis of Two Automated Fat-processing Systems

Improving the Retention of Low-Volume Autologous Fat Grafting: A Comparative Analysis of Lipoaspirate Processing Techniques for Facial Feminization

Background

Outcomes following autologous fat grafting have historically been unpredictable because of variability in fat retention rates. The novel poloxamer wash, absorption, mesh filtration system (PWAS) uses proprietary technology to stabilize and concentrate lipoaspirate. Its use in low-volume fat grafting has not been reported.

Objectives

The authors in this study aimed to compare PWAS technology with traditional lipoaspirate processing techniques in low-volume fat grafting procedures.

Methods

Medical charts were reviewed to determine a consecutive cohort of patients who underwent fat grafting for facial feminization. All patients had obtained preoperative and postoperative 3-dimensional facial imaging. Patients were grouped based on the method of lipoaspirate processing. The analysis software was used to measure changes in facial volume, and percent retention was calculated.

Results

Between September 2021 and February 2023, 11 facial fat grafting procedures were performed using the PWAS, and 5 performed using traditional lipoaspirate osmotic filtration with Telfa. Age and BMI were statistically similar between both the groups (P > .1). The average volume of lipoaspirate that was grafted was 23.4 mL (standard deviation [SD] 10.9 mL) and similar between both the groups (P > .1). The mean follow-up duration was 7.1 months (SD 3.1 months): 7.2 months, SD 3.5 months in the PWAS group vs 7.0 months, SD 2.2 months in the osmotic filtration group (P > .5). The average fat volume retention rate was 73.1% (SD 6.8%) in patients in whom the PWAS was used when compared with 46.1% (SD 5.2%) in patients in whom osmotic filtration was used (P > .01).

Conclusions

For patients undergoing low volume fat grafting, the PWAS technology may result in improved fat retention rates when compared with traditional lipoaspirate processing with Telfa.

Level of Evidence 4

Tissue engineering strategies for breast reconstruction: a literature review of current advances and future directions

Background and Objective

Mastectomy is a primary treatment for breast cancer patients, and both autologous and implant-based reconstructive techniques have shown excellent results. In recent years, advancements in bioengineering have led to a proliferation of innovative approaches to breast reconstruction. This article comprehensively explores the promising perspectives offered by bioengineering and tissue engineering in the field of breast reconstruction.

Methods

A literature review was conducted between April and June 2023 on PubMed and Google Scholar Databases. All English and French articles related to bioengineering applied to the field of breast reconstruction were included. We used the Evidence-Based Veterinary Medicine Association (EBVM) Toolkit 14 checklist for narrative reviews as a quality assurance measure and the Scale for the Assessment of Narrative Review Articles (SANRA) tool to self-assess our methodology.

Key Content and Findings

Over 130 references related to breast bioengineering were included. The analysis revealed four key applications: enhancing the quality of the skin envelope, improving the viability of fat grafting, creating breast shape and volume via bio-printing, and optimizing nipple reconstruction through engineering techniques. The primary identified approaches revolved around establishing structural support and enhancing cellular viability. Structural techniques predominantly involved the implementation of 3D printed, decellularized, or biocompatible material scaffolds. Meanwhile, promoting cellular content trophicity primarily focused on harnessing the regenerative potential of adipose-derived stem cells (ADSCs) and increasing the tissue's survivability and cell trophicity.

Conclusions

Tissue and bioengineering hold immense promise in the field of breast reconstruction, offering a diverse array of approaches. By combining existing techniques with novel advancements, they have the potential to significantly enhance the therapeutic options available to plastic and reconstructive surgeons.

Strategies to Improve AFT Volume Retention After Fat Grafting

BACKGROUND

Autologous fat grafting has gained increasing popularity used in plastic surgery as a strategy to improve functional and aesthetic outcome. However, variable augmentation results have concerned surgeons in that volume loss of grafted fat reported fluctuates unsteadily.

AIM

An optimal technique that clinically maximizes the long-term survival rate of transplantation is in urgent need to be identified.

METHOD

The PubMed/MEDLINE database was queried to search for animal and human studies published through March of 2022 with search terms related to adipose grafting encompassing liposuction, adipose graft viability, processing technique, adipose-derived stem cell, SVF and others.

RESULTS

45 in vivo studies met inclusion criteria. The principal of ideal processing technique is effective purification of fat and protection of tissue viability, such as gauze rolling and washing-filtration devices. Cell-assisted lipotransfer including SVF, SVF-gel and ADSCs significantly promotes graft retention via differentiation potential and paracrine manner. ADSCs induce polarization of macrophages to regulate inflammatory response, mediate extracellular matrix remodeling and promote endothelial cell migration and sprouting, and differentiate into adipocytes to replace necrotic cells, providing powerful evidence for the benefits and efficacy of cell-assisted lipotransfer.

CONCLUSION

Based on the current evidence, the best strategy can not be decided. Cell-assisted lipotransfer has great potential for use in regenerative medicine. But so far mechanically prepared SVF-gel is conducive to clinical promotion. PRP as endogenous growth factor sustained-release material shows great feasibility.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Surgical Decision Making in Autologous Fat Grafting: An Evidence-Based Review of Techniques to Maximize Fat Survival

Autologous fat grafting is an important tool in plastic surgery and is widely used for a variety of applications, both aesthetic and reconstructive. Despite an ever-increasing list of indications and extensive research over many years into improving outcomes, fat grafting remains plagued by incomplete and often unpredictable graft survival. Decisions made at each stage of surgery can potentially contribute to ultimate success, including donor site selection and preparation, fat harvest, processing, and purification of lipoaspirate, recipient site preparation, and delivery of harvested fat to the recipient site. In this review, we examine the evidence for and against proposed techniques at each stage of fat grafting. Areas of consensus identified include use of larger harvesting and grafting cannulas and slow injection speeds to limit cell damage due to shearing forces, grafting techniques emphasizing dispersion of fat throughout the tissue with avoidance of graft pooling, and minimizing exposure of the lipoaspirate to the environment during processing. Safety considerations include use of blunt-tipped needles or cannulas to avoid inadvertent intravascular injection as well as awareness of cannula position and avoidance of danger zones such as the subgluteal venous plexus. We believe that using the evidence to guide surgical decision-making is the key to maximizing fat grafting success. Level of Evidence: 4.

Fat Processing Techniques: A Narrative Review

OBJECTIVE

This study reviewed the literature regarding different fat processing techniques, in order to update the information for healthcare personnel and provide the latest evidence in selecting purification methods.

METHODS

PubMed (MEDLINE), EMBASE, the Cochrane Library, and the Cochrane Central Register of Controlled Trials were comprehensively searched to identify studies that compared different fat purification methods for animal and human studies published through July 2020. Papers were screened using inclusion and exclusion criteria, and relative data were collected for review.

RESULTS

A total of 3292 studies were identified, of which 30 were included for review. The findings of existing clinical studies showed that the filtration and washing filtration methods performed better in the volume retention rate of adipose tissue. In terms of postoperative complications (fat necrosis, nodules, cysts, etc.), the incidence of complications of centrifugation is generally higher than that of other purification methods, while Telfa gauze and washing filtration system show better safety. More comparative studies are needed to draw conclusions about clinical efficacy and satisfaction. The existing basic science studies generally believe that centrifugation has no advantage in the integrity and metabolic activity of adipose tissue. However, there is no definite conclusion about the volume retention rate of grafts in animal experiments.

CONCLUSION

In recent years, studies on the cost-effectiveness of various purification methods have emerged, and the efficiency advantages of commercial systems have also been gradually reflected. In the future, the purification efficiency will be improved based on ensuring clinical efficacy, which will be translated into cost savings.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .