Effect of Autologous Platelet-Rich Plasma Gel on Skin Flap Survival

Pharmacological and cell-based treatments to increase local skin flap viability in animal models

Local skin flaps are frequently employed for wound closure to address surgical, traumatic, congenital, or oncologic defects. (1) Despite their clinical utility, skin flaps may fail due to inadequate perfusion, ischemia/reperfusion injury (IRI), excessive cell death, and associated inflammatory response. (2) All of these factors contribute to skin flap necrosis in 10-15% of cases and represent a significant surgical challenge. (3, 4) Once flap necrosis occurs, it may require additional surgeries to remove the entire flap or repair the damage and secondary treatments for infection and disfiguration, which can be costly and painful. (5) In addition to employing appropriate surgical techniques and identifying healthy, well-vascularized tissue to mitigate the occurrence of these complications, there is growing interest in exploring cell-based and pharmacologic augmentation options. (6) These agents typically focus on preventing thrombosis and increasing vasodilation and angiogenesis while reducing inflammation and oxidative stress. Agents that modulate cell death pathways such as apoptosis and autophagy have also been investigated. (7) Implementation of drugs and cell lines with potentially beneficial properties have been proposed through various delivery techniques including systemic treatment, direct wound bed or flap injection, and topical application. This review summarizes pharmacologic- and cell-based interventions to augment skin flap viability in animal models, and discusses both translatability challenges facing these therapies and future directions in the field of skin flap augmentation.

Vasopressin-Induced Gangrene of the Bilateral Foot Digits and Right Index Finger Managed With Platelet-Rich Plasma Treatment

Bilateral foot digit gangrene generated by vasopressin is a serious complication for which management and treatment choices are extremely difficult. This case report presents a case of vasopressin-induced gangrene that was successfully treated with platelet-rich plasma (PRP) infiltration. A 20-year-old female patient came with a history of vasopressin treatment, causing bilateral foot digit gangrene and increasing necrosis. The patient's health quickly declined, and conventional care techniques had no effect on enhancing tissue perfusion or stopping the gangrene from getting worse. In our study, we have chosen to use PRP infiltration as an experimental therapeutic technique in light of the restricted choices available. This case study demonstrates the possibility of PRP infiltration as a cutting-edge and effective treatment for vasopressin-induced bilateral foot digit gangrene. The potential of PRP to stimulate angiogenesis, tissue regeneration, and wound healing is essential for optimizing the patient's results. For vasopressin-induced gangrene, more studies are required to evaluate the efficacy of PRP infiltration as a common therapy approach. This case study highlights the important role that PRP infiltration plays in enhancing tissue perfusion, stopping the advancement of necrosis, and promoting recovery.

Evaluation of Survival of Subdermal Plexus Skin Flaps in 8 Cats After Injection of Platelet Rich Plasma

The aim of the present study was to evaluate the effect of platelet-rich plasma injection on the survival of experimentally developed subdermal plexus skin flaps in cats. Two flaps, 2 cm wide and 6 cm long were created bilaterally in the dorsal midline in 8 cats. Each flap was randomized to 1 of 2 groups: platelet-rich plasma injection and control. After flap development, the flaps were immediately placed back on the recipient bed. Then 1.8 mL of platelet-rich plasma was equally injected into 6 different parts of the treatment flap. All flaps were evaluated macroscopically daily and on days 0, 7, 14, and 25 by planimetry, Laser Doppler flowmetry, and histology. Mean flap survival on day 14 was 80.437 % (±22.745) for the treatment group and 66.516 % (±24,12) for the control group with no statistically significant difference between the 2 groups (P = .158). Histologically, a significant difference was found between the base of the PRP and the control flap in edema score on day 25 (P = .034). In conclusion, there is no evidence to support the use of platelet-rich plasma in subdermal plexus flaps in cats. However, the use of platelet-rich plasma may aid in reducing edema of subdermal plexus flaps.

[Renaissance of prepectoral implant-based breast reconstruction: theoretical basis and research status]

Objective

To overview the theoretical basis and research status of prepectoral implant-based breast reconstruction.

Methods

The domestic and foreign researches on the application of prepectoral implant-based breast reconstruction in breast reconstruction were retrospectively analyzed. The theoretical basis, clinical advantages, and limitations of this technique were summarized and the future development trend in this field was discussed.

Results

The recent advances in breast cancer oncology, the development of materials and the concept of oncology reconstruction have provided a theoretical basis for prepectoral implant-based breast reconstruction. The selection of patients and the experience of surgeons are crucial for postoperative outcomes. Ideal thickness and blood flow of flaps are the most important considerations for the selection of prepectoral implant-based breast reconstruction. However, its long-term reconstruction outcomes and clinical benefits and risks in Asian populations still need to be confirmed by more studies.

Conclusion

Prepectoral implant-based breast reconstruction has a broad application prospect in breast reconstruction following mastectomy. However, the evidence is limited at present. Randomized study with long-term follow-up is urgently in need to provide sufficient evidence to evaluate the safety and reliability of prepectoral implant-based breast reconstruction.

Application of Autogenous Dermis Combined With Local Flap Transplantation in Repair of Titanium Mesh Exposure After Cranioplasty

OBJECTIVES

To investigate the clinical outcome of autogenous dermis combined with local flap transplantation in the treatment of titanium mesh exposure after cranioplasty.

METHODS

We studied a total of 8 patients with titanium mesh exposure after cranioplasty. After debridement of the head wound, the autogenous dermal tissue from the lateral thigh was transplanted to the surface of titanium mesh, and the local skin flap was then applied after suturing and fixation to repair the wound on the surface of the dermis. To repair the lateral thigh dermal tissue area, a local skin flap was obtained, and a blade thick skin graft was used.

RESULTS

Both dermal tissue and local skin flap survived. In the meanwhile, the donor skin area of the lateral thigh healed well, with only slight scar hyperplasia, and the titanium mesh was preserved. There was no recurrence after 6 months of follow-up.

CONCLUSIONS

The application of autogenous dermis combined with local skin flap to repair titanium mesh exposure can effectively avoid skin flap necrosis, potential re-exposure of titanium mesh, sub-flap effusion, infection, and other problems. This method has an ideal effect, has easy access to materials, and reduces patients' economic burden. It is worth popularizing.

Photoacoustic microscopy: a novel approach for studying perforator skin flap in a mouse model

Background

A comprehensive understanding of cutaneous microvessels is key to the design and use of the perforator skin flap. Compared with the various imaging technologies that have been applied in the clinical practice of the perforator skin flap, photoacoustic microscopy (PAM) is a very promising noninvasive imaging modality with high resolution and deep penetration in biological tissues.

Methods

PAM was employed to explore its multiple applications in a perforator skin flap. The following experiments were then conducted in 3 parts. In part 1, 7 mice were used to obtain the preoperative perforator mapping on the mouse back. In parts 2 and 3, 7 mice were used to design and harvest the multiterritory perforator flap. The status of the flap and the morphological changes of choke vessels were subsequently observed by PAM at several time points.

Results

The results showed that PAM could visualize and assess the vascular physiological and pathological conditions of the skin tissue in real time in vivo with high spatial and temporal resolution. It could also provide preoperative perforator mapping, including the total number of perforators, localization, vascular territories, and diameter. Furthermore, it could offer a quantitative, objective method to monitor the status of the perforator skin flap, and was capable of noninvasive characterization of the changes of choke vessels that play an important role in multiterritory perforator skin flap expansion and survival.

Conclusions

PAM has great potential to be an effective and precise quantitative imaging tool for perforator skin flap research, such in as flap design, monitoring, and choke vessel observation.

Effect of Bone Marrow Mesenchymal Stem Cell Sheets on Skin Capillary Parameters in a diabetic wound model: A Novel Preliminary Study

Background

Treatment with BMMSCs has anti-inflammatory, tissue regenerative, angiogenic, and immune-stimulating effects. When using as sheets or accumulate, BMMSCs causes the development of neoangiogenesis in damaged skin tissue. Diabetes, a metabolic disorder, can negatively affect many physiological functions, including the process of skin injury repair. This adverse impact may increase the risk of skin surgery. RSF is commonly used in reconstructive surgery. The terminal part of the RSF is often affected by necrosis because of impaired blood flow, which is exacerbated in diabetes. This study investigated the effect of stem cells, applied as accumulated or cell sheets, along with RSF surgery on skin capillaries in STZ-induced diabetic rats.

Methods

Thirty male Wistar rats were divided into three groups (n = 10): diabetes-RSF control, diabetes-RSF local applied stem cells (loc-BMMSCs), diabetes-RSF applied stem cells as accumulated or cell sheets (ac-BMMSCs). Two weeks after the STZ injection, RSF surgery and stem cell therapy (6 × 109) were carried out (day zero). Furthermore, stereological methods were used to investigate the capillary patterns among the groups. Anti-CD31/PCAM1 immunohistochemistry was also used for further confirmation of changes in capillary parameters.

Results

The results demonstrated that capillaries were protected by MSC sheets in the flap tissue, and the thickness of the epidermal layer was improved, indicationg the possible beneficial effects of MSC sheets on diabetic wound treatment.

Conclusion

Stem cells, as ac-BMMSCs, may decrease the levels of wound healing complications in diabetes and can be considered as a cell therapy option in such conditions.

Investigation of transcriptome profile of ischemia/reperfusion injury of abdominal skin flaps in rats after methane-rich saline treatment using RNA-seq

OBJECTIVE

Here we examined the influence of methane-rich saline treatment (MS) on the whole transcriptome of the skin flaps during the ischemia/reperfusion (I/R) injuryusing RNA-sequence (RNA-seq).

METHODS

The rats were divided into three groups: the sham surgery group (SH),the I/R surgery group treated with physiological saline (I/R-P) or the I/R surgery group treated with the methane-rich saline (I/R-M) respectively. On the 72 hours after operation, the perfusion and the distribution of micro-circulatoryblood flow in skin flaps were observed by laser doppler flowmeters. The whole transcriptome alteration of the skin flaps was examined using RNA-seq. Moreover, the responses of the skin flaps to MRS treatment were examined using bio-informatic and q-PCR approaches after I/R injury.

RESULTS

The methane-rich saline (MS) treatment could expand survival area and improve the blood perfusion of the skin flaps after l/R injury. Compared to the I/R-P group, 474 genes significantly altered in the I/R-M group. These genes were mainly associated the development, the cell adhesion and migration. In addition, the PI3K-Akt signal pathway was meaningfully related to regulation of MS treatment. Q-PCR results confirmed that MS treatment positively regulated PI3K-Akt signal pathway relative genes and inhibited the cell adhesion relative genes.

CONCLUSION

These results proved that methane-rich saline may alleviate I/R injury and improve flap survival rate by regulating cell adhesion and PI3K-Akt signal pathway.

The effects of platelet-rich plasma combined with a skin flap transplant on open foot fractures with soft tissue defects

OBJECTIVE

This study aimed to explore the therapeutic effect of surgery using platelet-rich plasma combined with a skin flap transplant on open foot fractures with a soft tissue defect.

METHODS

From February 2017 to March 2020, 72 patients with open foot fractures and soft tissue defects were recruited as the study cohort. The patients who underwent surgery with just a flap transplant were placed in the control group (the CG) (35 cases), and the patients who underwent surgery using platelet-rich plasma combined with a flap transplant were placed in the research group (the RG) (37 cases). The wound volume changes before and after the treatment, the wound healing times, the fracture healing times, and any adverse prognostic reactions were observed. The pre- and post-treatment VAS and SF-36 scores were observed and recorded.

RESULTS

The total effective rate in the RG (100.00%) was significantly higher than the total effective rate in the CG (88.57%) (P=0.034). After the treatment, the wound volumes were lower in both groups, and the volume in the RG was smaller than it was in the CG at 3 weeks and 6 weeks after the treatment (P < 0.05). The average wound healing time in the RG (22.40 ± 2.10 days) was significantly lower than it was in the CG (32.20 ± 3.30 days) (P > 0.05). The average fracture healing time in the RG (6.50 ± 2.20 months) was significantly lower than it was in the RG (7.51 ± 2.33 months) (P > 0.05). The total incidence of adverse reactions to the treatment in the RG was 2.70%, and in the CG it was 11.43%. After the treatment, the VAS scores in the RG were significantly lower than they were in the CG (P < 0.05), and the SF-36 scores in the RG were significantly higher than the SF-36 scores in the CG (P < 0.05).

CONCLUSION

Platelet-rich plasma combined with a skin flap transplant can accelerate the healing times of wounds and fractures and lessen the occurrence of adverse reactions during the patients' treatment.

The secretome of stressed peripheral blood mononuclear cells increases tissue survival in a rodent epigastric flap model

Reconstructive surgery transfers viable tissue to cover defects and to restore aesthetic and functional properties. Failure rates after free flap surgery range from 3 to 7%. Co-morbidities such as diabetes mellitus or peripheral vascular disease increase the risk of flap failure up to 4.5-fold. Experimental therapeutic concepts commonly use a monocausal approach by applying single growth factors. The secretome of γ-irradiated, stressed peripheral blood mononuclear cells (PBMCsec) resembles the physiological environment necessary for tissue regeneration. Its application led to improved wound healing rates and a two-fold increase in blood vessel counts in previous animal models. We hypothesized that PBMCsec has beneficial effects on the survival of compromised flap tissue by reducing the necrosis rate and increasing angiogenesis. Surgery was performed on 39 male Sprague-Dawley rats (control, N = 13; fibrin sealant, N = 14; PBMCsec, N = 12). PBMCsec was produced according to good manufacturing practices (GMP) guidelines and 2 ml were administered intraoperatively at a concentration of 2.5 × 107 cells/ml using fibrin sealant as carrier substance. Flap perfusion and necrosis (as percentage of the total flap area) were analyzed using Laser Doppler Imaging and digital image planimetry on postoperative days 3 and 7. Immunohistochemical stainings for von Willebrand factor (vWF) and Vascular Endothelial Growth Factor-receptor-3 (Flt-4) were performed on postoperative day 7 to evaluate formation of blood vessels and lymphatic vessels. Seroma formation was quantified using a syringe and flap adhesion and tissue edema were evaluated clinically through a cranial incision by a blinded observer according to previously described criteria on postoperative day 7. We found a significantly reduced tissue necrosis rate (control: 27.8% ± 8.6; fibrin: 22.0% ± 6.2; 20.9% reduction, p = .053 vs. control; PBMCsec: 19.1% ± 7.2; 31.1% reduction, p = .012 vs. control; 12.9% reduction, 0.293 vs. fibrin) together with increased vWF+ vessel counts (control: 70.3 ± 16.3 vessels/4 fields at 200× magnification; fibrin: 67.8 ± 12.1; 3.6% reduction, p = .651, vs. control; PBMCsec: 85.9 ± 20.4; 22.2% increase, p = .045 vs. control; 26.7% increase, p = .010 vs. fibrin) on postoperative day 7 after treatment with PBMCsec. Seroma formation was decreased after treatment with fibrin sealant with or without the addition of PBMCsec. (control: 11.9 ± 9.7 ml; fibrin: 1.7 ± 5.3, 86.0% reduction, 0.004 vs. control; PBMCsec: 0.6 ± 2.0; 94.8% reduction, p = .001 vs. control; 62.8% reduction, p = .523 vs. fibrin). We describe the beneficial effects of a secretome derived from γ-irradiated PBMCs on tissue survival, angiogenesis, and clinical parameters after flap surgery in a rodent epigastric flap model.

Platelet-rich plasma accelerates skin wound healing by promoting re-epithelialization

BACKGROUND

Autologous platelet-rich plasma (PRP) has been suggested to be effective for wound healing. However, evidence for its use in patients with acute and chronic wounds remains insufficient. The aims of this study were to comprehensively examine the effectiveness, synergy and possible mechanism of PRP-mediated improvement of acute skin wound repair.

METHODS

Full-thickness wounds were made on the back of C57/BL6 mice. PRP or saline solution as a control was administered to the wound area. Wound healing rate, local inflammation, angiogenesis, re-epithelialization and collagen deposition were measured at days 3, 5, 7 and 14 after skin injury. The biological character of epidermal stem cells (ESCs), which reflect the potential for re-epithelialization, was further evaluated in vitro and in vivo.

RESULTS

PRP strongly improved skin wound healing, which was associated with regulation of local inflammation, enhancement of angiogenesis and re-epithelialization. PRP treatment significantly reduced the production of inflammatory cytokines interleukin-17A and interleukin-1β. An increase in the local vessel intensity and enhancement of re-epithelialization were also observed in animals with PRP administration and were associated with enhanced secretion of growth factors such as vascular endothelial growth factor and insulin-like growth factor-1. Moreover, PRP treatment ameliorated the survival and activated the migration and proliferation of primary cultured ESCs, and these effects were accompanied by the differentiation of ESCs into adult cells following the changes of CD49f and keratin 10 and keratin 14.

CONCLUSION

PRP improved skin wound healing by modulating inflammation and increasing angiogenesis and re-epithelialization. However, the underlying regulatory mechanism needs to be investigated in the future. Our data provide a preliminary theoretical foundation for the clinical administration of PRP in wound healing and skin regeneration.

The Effects of Platelet-Rich Plasma to Decrease the Risk of Seroma Formation After Mastectomy and Axillary Dissection

BACKGROUND

Seroma, which is the most common complication after mastectomy and axillary dissection, is the leakage of the lymphovascular fluid into the dead space. It can cause local complications varying from delayed wound healing to infection and skin flap necrosis. The aim of this study was to evaluate whether platelet-rich plasma (PRP) reduces the risk of seroma formation.

MATERIALS AND METHODS

A total of 24 Wistar albino rats were randomly divided into three groups of eight rats in each. For the rats in group 1, no additional procedures were carried out. The rats in groups 2 and 3 were applied with 0.25 and 0.5 mL/cm² PRP, respectively, to the operation site. The groups were compared in respect of adhesion scores, histopathologic examination, and tissue seroma volume.

RESULTS

The mean seroma volume was 2.19 ± 0.78 mL in group 1, 1.43 ± 0.35 mL in group 2, and 0.96 ± 0.24 mL in group 3. The seroma volumes of groups 3 and 2 were significantly lower than those in group 1. In the macroscopic assessment the mean general adhesion score was 6 ± 0.75 in group 3. The other general adhesion scores were 5.25 ± 0.70 and 2.12 ± 0.64 in groups 2 and 1, respectively. The adhesion scores of groups 3 and 2 were significantly higher than those of group 1. The mean inflammatory cell score was 0.87 ± 0.83 in group 3, 2.0 ± 0.92 in group 2, and 3.0 ± 0.53 in group 1. There were significantly lower levels of inflammatory cells in group 3 than in the other groups and the group 2 inflammatory cell count was lower than that of group 1. Fibroblast density score was significantly higher in group 3 (2.50 ± 1.06) compared with the other groups. Neovascularization was significantly higher in groups 3 and 2 compared with group 1. The mean neovascularization score was 2.25 ± 1.16 and 2.12 ± 1.12 in groups 2 and 3, respectively. There were no statistically significant differences between the groups in respect of collagen levels.

CONCLUSIONS

Local application of PRP in rats after experimental mastectomy and axillary dissection was observed to decrease seroma formation and to increase neovascularization and fibroblast density.

Standardizing the classification of skin tears: validity and reliability testing of the International Skin Tear Advisory Panel Classification System in 44 countries

BACKGROUND

Skin tears are acute wounds that are frequently misdiagnosed and under-reported. A standardized and globally adopted skin tear classification system with supporting evidence for diagnostic validity and reliability is required to allow assessment and reporting in a consistent way.

OBJECTIVES

To measure the validity and reliability of the International Skin Tear Advisory Panel (ISTAP) Classification System internationally.

METHODS

A multicountry study was set up to validate the content of the ISTAP Classification System through expert consultation in a two-round Delphi procedure involving 17 experts from 11 countries. An online survey including 24 skin tear photographs was conducted in a convenience sample of 1601 healthcare professionals from 44 countries to measure diagnostic accuracy, agreement, inter-rater reliability and intrarater reliability of the instrument.

RESULTS

A definition for the concept of a 'skin flap' in the area of skin tears was developed and added to the initial ISTAP Classification System consisting of three skin tear types. The overall agreement with the reference standard was 0·79 [95% confidence interval (CI) 0·79-0·80] and sensitivity ranged from 0·74 (95% CI 0·73-0·75) to 0·88 (95% CI 0·87-0·88). The inter-rater reliability was 0·57 (95% CI 0·57-0·57). The Cohen's Kappa measuring intrarater reliability was 0·74 (95% CI 0·73-0·75).

CONCLUSIONS

The ISTAP Classification System is supported by evidence for validity and reliability. The ISTAP Classification System should be used for systematic assessment and reporting of skin tears in clinical practice and research globally. What's already known about this topic? Skin tears are common acute wounds that are misdiagnosed and under-reported too often. A skin tear classification system is needed to standardize documentation and description for clinical practice, audit and research. What does this study add? The International Skin Tear Advisory Panel Classification System was psychometrically tested in 1601 healthcare professionals from 44 countries. Diagnostic accuracy was high when differentiating between type 1, 2 and 3 skin tears using a set of validated photographs.

Biological coating with platelet-rich plasma and adipose tissue-derived microvascular fragments improves the vascularization, biocompatibility and tissue incorporation of porous polyethylene

Porous polyethylene (pPE) is a commonly used biomaterial in craniofacial reconstructive surgery. However, implant failure due to insufficient vascularization represents a major issue. To overcome this problem, we herein introduce an effective strategy to improve the vascularization and incorporation of pPE. Adipose tissue-derived microvascular fragments (MVF) from transgenic green fluorescent protein (GFP)⁺ mice were suspended in platelet-rich plasma (PRP) for the coating of pPE. PRP/MVF-coated pPE as well as PRP-coated and uncoated controls were subsequently implanted into the dorsal skinfold chamber and the flanks of GFP^- wild-type mice to analyze their in vivo performance throughout 2, 4 and 8 weeks by means of intravital fluorescence microscopy, histology and immunohistochemistry. The GFP⁺/GFP^- cross-over design allowed the identification of GFP⁺ MVF within the implants. Shortly after implantation, they rapidly reassembled into new blood-perfused microvascular networks, resulting in a significantly accelerated vascularization of PRP/MVF-coated pPE when compared to both controls. The overall numbers of rolling and adherent leukocytes within the microcirculation as well as macrophages, multi-nucleated giant cells and mast cells around the implants did not differ between the three groups. However, in contrast to uncoated controls, PRP/MVF-coated and PRP-coated pPE promoted pro-angiogenic M2 macrophage polarization at the implantation site. These findings demonstrate that PRP/MVF-coating represents a highly effective strategy to enhance the vascularization, biocompatibility and tissue incorporation of pPE. STATEMENT OF SIGNIFICANCE: The clinical in vivo performance of implanted biomaterials is crucially dependent on their adequate incorporation into the body. To achieve this, we herein introduce an effective biological coating strategy. Our results demonstrate that coating with PRP and MVF accelerates and enhances the vascularization, biocompatibility and tissue incorporation of porous polyethylene. Because this type of biological coating is easily applicable on any type of biomaterial, our approach may rapidly be translated into clinical practice to improve the outcome of various regenerative approaches.