Do Stem Cells Have an Effect When We Fat Graft?

Use of autologous adipose tissue in acute burn wound management: A systematic review

Fat transfer is increasingly used as part of our reconstructive armamentarium to address the challenges encountered in burn wounds and reconstructive surgery. The present systematic review aimed to evaluate the effectiveness of autologous fat transfer for acute burn wound management. A systematic review of the US National Library of Medicine, Cochrane Library, Web of Science, and Embase was conducted on October 15, 2022 (registration number CDR42022369726). A database watch was performed until submission of the manuscript. The review focused on wound healing. All studies reporting fat transfer in adult patients (at least 5 patients reported) with deep 2nd degree burn wounds were included. The database search yielded a total of 720 records and 367 patients were included from 3 studies. A statistically significant improvement in scar texture, scar appearance, and time to healing was reported in one study in the fat transfer group versus control (P<0.001). Similarly, scores for scar color, scar thickness, scar stiffness, and scar regularity increased significantly. The small number of included studies and their heterogeneity did not allow a meta-regression to be performed. This systematic review emphasizes the limited evidence currently available regarding the use of autologous fat transfer to improve burn wound healing in adult patients, even though it seems promising. Future search should focus on randomized controlled trials with a larger number of participants.

Fat Grafting Reduces Skin Hyperpigmentation of Localized Scleroderma Patients: A Prospective Self-controlled Study

BACKGROUND

Localized scleroderma (LS) is characterized by skin fibrosis, hyperpigmentation and soft tissue atrophy. Fat grafting has been widely used to correct LS deformity.

OBJECTIVE

To investigate the effect of fat grafting on the skin pigmentation of LS lesions.

METHODS

A prospective self-controlled study was conducted. Skin melanin and erythema indexes were measured by Mexameter® MX18 before and 3 months after surgery. Differences between lesions and contralateral normal sites were compared to evaluate changes induced by fat grafting. Localized Scleroderma Cutaneous Assessment Tool and PUMC Localized Scleroderma Facial Aesthetic Index were used for clinical evaluation.

RESULTS

Fourteen frontal linear LS patients participated in the study. Before surgery, the melanin index of the lesions was significantly higher than the contralateral sites (p = 0.023), while the erythema indexes were not significantly different (p = 0.426). Three months post-operation, the melanin index of the lesions significantly decreased (p = 0.008). There was no significant change in the erythema index of the lesions before and after fat grafting (p = 0.322). The LoSCAT and PUMC LSFAI scores demonstrated improved disease condition and facial esthetics after surgery.

CONCLUSION

Fat grafting could alleviate skin hyperpigmentation and skin damage of LS lesions while having little effect on skin erythema and disease activity.

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 .

Repair of cerebrospinal fluid leak during posterior thoracolumbar surgery using paraspinal muscle flap combined with fat graft

Objective

This study aimed to propose a novel surgical method via combination of fat graft and paraspinal muscle flap, in order to treat cerebrospinal fluid (CSF) leak during posterior thoracolumbar surgery. The clinical outcomes were also evaluated.

Methods

Data of a total of 71 patients who were diagnosed with intraoperative incidental durotomy and CSF leak after posterior thoracolumbar surgery in our hospital form January 2019 to January 2021 were retrospectively collected and analyzed. Among them, 34 and 37 patients were assigned into conventional suturing (CS) group and fat graft and paraspinal muscle flap (FPM) group, respectively. Patients’ demographic and clinical data were compared between the two groups.

Results

The average drainage tube time in the FPM group was 3.89 ± 1.17 days, which was shorter than that in the CS group (5.12 ± 1.56, P < 0.001). The drainage volume in the FPM group (281.08 ± 284.76 ml) was also smaller than that in the CS group (859.70 ± 553.11 ml, P < 0.001). Besides, 15 (44.11%) patients in the CS group complained of postural headache, which was more than that in the FPM group (7 patients, 18.91%). There was a statistically significant difference in postoperative visual analogue scale (VAS) score between the two groups (P = 0.013). Two patients underwent revision surgery resulting from incision nonunion and delayed meningeal cyst.

Conclusion

Fat graft combined with paraspinal muscle flap showed to be an effective method to repair CSF leak during posterior thoracolumbar surgery. The proposed method significantly reduced postoperative drainage tube time and postoperative drainage volume. It also decreased the incidence and the degree of postural headache. The proposed method showed satisfactory clinical outcomes, and it is worthy of promotion.

Adipose-Derived Stem Cells Exosomes Improve Fat Graft Survival by Promoting Prolipogenetic Abilities through Wnt/β-Catenin Pathway

Autologous fat grafting has been widely used in plastic surgery in recent years, but the unstable retention of fat graft has always been a key clinical problem. Adipose tissue has poor tolerant to ischemia, so the transplanted adipose tissue needs to rebuild blood supply at an early stage in order to survive stably. Our previous study has found that comparing to human foreskin fibroblast exosome (HFF-Exo), human adipose-derived stem cells exosome (hADSC-Exo) can significantly improve the proliferation of vascular endothelial cells and the angiogenic effect of artificial dermal preconstructed flaps. Therefore, the ability of hADSC-Exo to improve the retention of adipose grafts and its potential regenerative mechanism aroused our strong interest. In this study, we applied hADSC-Exo and HFF-Exo to adipose grafts and explored the potential regeneration mechanism through various means such as bioinformatics, immunofluorescence, immunohistochemistry, and adipogenic differentiation. The results showed that hADSC-Exo can significantly promote grafts angiogenesis and adipogenic differentiation of ADSC to improve the retention of fat grafts and may downregulate the Wnt/β-catenin signaling pathway to promote the adipogenic differentiation. In summary, our results provide a theoretical basis for the clinical translation of hADSC-Exo in fat grafting.

Radiation-Induced Tissue Damage: Clinical Consequences and Current Treatment Options

Radiation therapy is a valuable tool in the treatment of numerous malignancies but, in certain cases, can also causes significant acute and chronic damage to noncancerous neighboring tissues. This review focuses on the pathophysiology of radiation-induced damage and the clinical implications it has for plastic surgeons across breast reconstruction, osteoradionecrosis, radiation-induced skin cancers, and wound healing. The current understanding of treatment modalities presented here include hyperbaric oxygen therapy, autologous fat grafting and stem cells, and pharmaceutical agents.

Effects of low-level laser therapy and adipose-derived stem cells on the viability of autologous fat grafts: a preliminary study

Background Autologous fat grafts are commonly used in cosmetic and reconstructive surgery, and various methods are used to improve their viability. Low-level laser therapy (LLLT) can enhance the proliferation, growth, and differentiation of various cell lines, including stem cells. Our study investigated and compared the effects of LLLT and the addition of adipose-derived stem cells (ADSCs) on the viability of fat grafts.Methods Twenty nude mice were divided into four groups: control (group 1), LLLT irradiation (group 2), ADSC addition (group 3), and LLLT irradiation+ADSC addition (group 4). ADSCs were combined with the fat tissue. LLLT irradiation was performed once daily for 1 week from the day of grafting. After 8 weeks, the weight, volume, histology, and Western blot findings of the grafted fat tissues were evaluated.Results The retention rate and volume of the fat tissue in groups 2, 3, and 4 were higher than that of group 1, but the difference was not statistically significant. The number of capillaries, histological parameters, and immunofluorescence staining analyses for CD68, CD31, fibroblast growth factor, and vascular endothelial growth factor (VEGF) showed no significant differences among the four groups. The expression level of VEGF was higher in group 2 than in the other groups, but not to a statistically significant level.Conclusions LLLT and ADSCs did not significantly improve the viability of autologous fat grafts. Therefore, further study is necessary to develop safe and effective methods to improve the viability of these grafts for clinical application.

The Effects of Vasonatrin Peptide on Fat Graft Viability: An Experimental Study

Vasonatrin peptide (VNP) is a synthetic peptide that possesses vasodilatory, natriuretic, and anti-inflammatory properties. The authors aimed to analyze the effects of VNP on fat graft survival. Twenty Sprague-Dawley rats are randomly divided into two groups of 10. Fat grafts are harvested from the right inguinal region. After preparation, fat grafts are placed to the interscapular region. The first group of rats were administered VNP after their fat injection, while the second group received tail-vein injections of an equal volume of sterile saline following their fat injection. Experiment and control groups are evaluated according to their level of degeneration of adipocytes, fat necrosis, vacuolization, cyst formation in adipocytes, fibrosis of the fat tissue, capillary density, and CD31 immunohistochemical staining. Degeneration, vacuolization, and cyst formation in adipocytes were lower in the experiment group. Increased capillary density in the experiment group was demonstrated by CD31 antibody staining and by counting capillary density under a microscope. The average percentage of change in weight of the fat grafts in the experiment group was lower than that in the control group. The results indicate that VNP has some beneficial effects on fat graft survival by multiple independent mechanisms that influence both local and systemic homeostasis.

Autologous Fat Grafting for Oncologic Patients: A Literature Review

Autologous fat grafting (AFG) serves as an effective method to address volume defects, contour irregularities, and asymmetry in both aesthetic and reconstructive procedures. In recent years, there has been growing concern about the potential of cancer recurrence and interference with cancer surveillance in oncologic patients receiving AFG. The adipose tissue contains adipose-derived stem cells (ASCs), a specific type of mesenchymal stem cells, that facilitate secretion of numerous growth factors which in turn stimulate tissue regeneration and angiogenesis. As such, it has been theorized that ASCs may also have the potential to stimulate cancer cell proliferation and growth when used in oncologic patients. Multiple research studies have demonstrated the ability of ACSs to facilitate tumor proliferation in animal models. However, clinical research in oncologic patients has yielded contradictory findings. Although the literature pertaining to oncologic safety in head and neck, as well as sarcoma, cancer patients remains limited, studies demonstrate no increased risk of tumor recurrence in these patient populations receiving AFG. Similarly, both the efficacy and safety of AFG have been well established in breast cancer patients through numerous clinical studies. More recently, preclinical research in animal models has shown that AFG has the potential to facilitate tissue regeneration and improve joint contracture following irradiation. Ultimately, further research is needed to elucidate the safety of AFG in a variety of oncologic patients, as well as explore its use in tissue regeneration, particularly in the setting of radiotherapy. Level of Evidence: 4.

Long-Term Follow-Up After Fat Graft Myringoplasty: Do Size and Location Matter?

OBJECTIVE

To assess clinical and functional outcomes of a fat graft myringoplasty under local in an office setting.

STUDY DESIGN

Prospective case series.

SETTING

Tertiary care facility.

PATIENTS

Patients with a tympanic membrane (TM) perforation presenting between December 2005 and June 2019. Inclusion criteria included perforation size >25% of the surface of the pars tensa of the TM, entire perforation margins visualized through a transcanal view, and lack of spontaneous closure at the 6-month follow-up. The exclusion criteria were the presence of cholesteatoma, wet appearance of the mucosa in the tympanic cavity, ear discharge in the 3 months before surgery, or signs of ossicular inconsistency.

INTERVENTION

In-office fat graft myringoplasty technique under local anesthesia.

MAIN OUTCOME MEASURES

Complete perforation closure rate and audiometric outcomes.

RESULTS

A total of 121 patients underwent the procedure, of whom 21 had bilateral sequential procedures (total 142 ears). Average age was 51.1 ± 18.4 years (range, 3-78 years). The size of perforation was <25% of TM in 39 (27.5%) ears, 25% to 50% of TM in 49 (34.55%) ears, 50% to 75% of TM in 34 (23.91%) ears, and 75% to 100% of TM in 20 (14.10%) ears. Complete perforation closure was evident in 130 (91.55%) of the 142 ears. Preoperative mean air conduction threshold was 59.3 dB (17-95 dB) and significantly improved into 35.6 dB (10-85 dB; P < .0004) after surgery. Preoperative air-bone gap was 30.2 dB (5-70 dB) and also significantly improved into 10.2 dB (5-65 dB; P < .0001) after surgery.

CONCLUSION

In office fat graft myringoplasty, in adult and pediatric patients with variable perforation sizes, is a well-tolerated procedure with very satisfactory clinical results.

Deferoxamine Protects Stromal/Stem Cells of "Lull pgm System"-Processed Lipoaspirates Against Damages Induced by Mitochondrial Respiration Inhibition

BACKGROUND

The ischemic environment of the receiving area compromises the outcome of autologous fat grafts. The aim of this study was to isolate and expand the stromal vascular fraction from patient lipoaspirates and investigate the gain in cell viability exerted by some protective agents against the blockage of mitochondrial respiration.

METHODS

The aspirates were (1) washed, using the "Lull pgm system," (2) centrifuged and (3) decanted. The corresponding stromal vascular fractions were isolated, and after cell adherence selection, the stromal/stem cell subpopulations were exposed to Antimycin A for 1 h. Then, the protection induced by cell pretreatment with deferoxamine, diazoxide and IGF-1 was evaluated.

RESULTS

The residual cell viability of the "Lull pgm system"-washed samples was greater than that of the centrifuged samples (p < 0.05), and this advantage was maintained during the following 12 days of culture. The administration of 400 μM deferoxamine before Antimycin A treatment increased the number of viable cells from 56.5 to 80.8% (p < 0.05). On the contrary, the pretreatment with 250 μM diazoxide or 0.1 μg/ml IGF-1 did not exert any significant pro-survival action. Echinomycin abolished the positive effect of deferoxamine, suggesting that its protection involved HIF-1α.

CONCLUSIONS

Adipose-derived stromal-stem cells survive the inhibition of mitochondrial respiration better if the lipoaspirate is washed using the "Lull pgm system" rather than centrifuged. Moreover, a significant contribution to cell survival can be obtained by preconditioning stromal-stem cells with deferoxamine. In a clinical perspective, this drug could be safely administered before surgery to patients undergoing autologous fat transfer.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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.

Risk factors and complications after body-contouring surgery and the amount of stromal vascular fraction cells found in subcutaneous tissue

Body contouring surgery following massive weight loss is often prone to complications. Subcutaneous adipose tissue is a rich source of stromal vascular fraction (SVF) cells, and moreover it plays an important role in the pathophysiology of obesity, metabolic syndrome, and wound healing. In this retrospective, single-centred appraisal, complications are examined and correlated with individual SVF numbers in abdominal subcutaneous fat tissue. We analysed whether the weight loss method affected complications. Eighty seven massive weight loss patients undergoing body contouring surgery between 2010 and 2017 were included in the study. In total, 57 cases with at least one complication were recorded (65.5%). Maximum lifetime weight was 109.6 kg (range 48-184 kg). Half of the complications (50.8%) were minor complications without the need for surgical revision. The mean number of SVF found in the resected tissue was 714 997.63 cells/g fat tissue. We found no statistical difference in complication rates dependent on cell numbers. Smoking (P = .049) and a high BMI at the time point of surgery (P = .031) led to significantly more complications. Also, a high resection weight (P = .057) showed a tendency for impaired wound healing. However, there was no difference in complication rates following body contouring procedures attributable to the method of weight loss in this study.

Office-Based Autologous Fat Injection Laryngoplasty for Glottic Insufficiency in Patients Under 50 Years Old

OBJECTIVE

We sought to determine the outcomes of office-based autologous fat injection laryngoplasty in the treatment of patients under 50 years old with glottic insufficiency but without neurological problems or acquired organic lesions in the vocal fold.

METHODS

We conducted a retrospective chart review of consecutive patients under 50 years of age who underwent office-based autologous fat injection laryngoplasty for glottic insufficiency. None of the patients presented neurological problems or acquired organic lesions in the vocal fold. Videolaryngostroboscopic data, objective voice assessment, perceptual measurements of vocal quality, and subjective ratings of voice quality were evaluated before and after treatment.

RESULTS

The 23 patients (7 men and 16 women) in this study presented significant improvements in phonatory function in terms of maximum phonation time, jitter, grade, asthenia, and Voice Handicap Index-10 (VHI-10) values at 3 months. Significant improvements in terms of jitter, noise-to-harmonic ratio, grade, roughness, breathiness, asthenia, and the VHI-10 values were also observed at 6 months.

CONCLUSIONS

Glottic insufficiency in younger patients without neurological problems or acquired organic lesions in the vocal fold can be treated effectively using office-based autologous fat injection laryngoplasty. Significant improvements in phonatory function were observed even 6 months after surgery.

Autologous Fat Grafting in Severe Lower Extremity Asymmetries: Report of Four Cases

Background: Lower extremity asymmetries are challenging problems in plastic and aesthetic surgery practice. Regardless of their origin, atrophies and asymmetries can be extremely varied and difficult to solve with simple techniques.

Objectives:  The author reports his experience in the treatment of four patients suffering from severe lower extremity atrophy and asymmetry of different etiologies with autologous fat grafting.

Methods: A total of four cases are presented. Patient selection was based on the severity of atrophy and asymmetry. Two patients were treated with two sessions of simple fat grafting and two patients with one session of cell-enriched fat grafting. The end point in each session was determined by tension/blanching of soft tissues. All patients were followed up for at least 12 months after the last session. During the postoperative follow-up, variables, such as objective volume improvement, objective girth loss, return to daily activities, and patient satisfaction, were analyzed.

Results: The initial analysis of postoperative results showed a good patient satisfaction rate with no relevant complications and an early return to daily activities. Estimated mean volume improvement for simple fat grafting cases was estimated as 44% after two treatments. Mean volume improvement in cell-enriched fat grafting cases was estimated as 25% after only one treatment.

Conclusions: Autologous fat grafting is a safe, effective, and reliable technique to perform aesthetic and reconstructive reshaping of a lower extremity in cases of atrophy or severe asymmetry. Depending on the preoperative soft tissue compliance, cell-assisted fat grafting will play an important role in reducing the number of sessions to perform.