Negative pressure wound therapy as an adjunct in healing of chronic wounds

Long-term follow-up and exploration of the mechanism of stromal vascular fraction gel in chronic wounds

BACKGROUND

Chronic refractory wounds easily relapse and seriously affect the patients' quality of life. Previous studies have shown that stromal vascular fraction gel (SVF-gel) significantly promotes the early healing of chronic wounds; however, the mechanisms of SVF-gel function per se remain unclear, and a long-term follow-up is lacking. This study aims to explore the mechanisms of SVF-gel promoting the healing of chronic wounds and follow up the long-term efficacy of SVF-gel.

METHODS

Autologous SVF-gel transplantation was performed in 20 patients with chronic wounds (from March 2016 to September 2019), and the size of the wound before and after SVF-gel transplantation was observed. The conditioned medium (CM) was harvested from SVF-gel under serum-free, serum-deprivation and 10% fetal bovine serum (FBS) microenvironment in vitro, respectively. The concentration of the growth factors in the two kinds of gel-CM was tested, and their effects on the proliferation and migration of human dermal fibroblasts (HDFs) were detected.

RESULTS

All patients had 100% wound closure eventually, and the average time to complete closure was 28.3 ± 9.7 days. The time of follow-up ranged from 2 to 6 years, and there was no wound recurrence. Interestingly, the concentrations of epidermal growth factor and transforming growth factor β1 of the CM were higher in serum-free and serum-deprivation condition than in 10% FBS microenvironment (p < 0.05). Correspondingly, the proliferation and migration ability of HDFs treated with gel-CM from serum-free condition were stronger than those treated with gel-CM from serum-deprivation (2% FBS) or 10% FBS microenvironment (p < 0.05).

CONCLUSION

These results indicate that it is safe, effective, and lasting in effect to treat chronic wounds with SVF-gel and mechanisms of action that include secreting various cytokines and promoting cell proliferation and migration ability.

TRIAL REGISTRATION

Chinese Clinical Trail Registry, ChiCTR2000034624. Registered 12 July 2020-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=56058.

Chronic wounds

Chronic wounds are characterized by their inability to heal within an expected time frame and have emerged as an increasingly important clinical problem over the past several decades, owing to their increasing incidence and greater recognition of associated morbidity and socio-economic burden. Even up to a few years ago, the management of chronic wounds relied on standards of care that were outdated. However, the approach to these chronic conditions has improved, with better prevention, diagnosis and treatment. Such improvements are due to major advances in understanding of cellular and molecular aspects of basic science, in innovative and technological breakthroughs in treatment modalities from biomedical engineering, and in our ability to conduct well-controlled and reliable clinical research. The evidence-based approaches resulting from these advances have become the new standard of care. At the same time, these improvements are tempered by the recognition that persistent gaps exist in scientific knowledge of impaired healing and the ability of clinicians to reduce morbidity, loss of limb and mortality. Therefore, taking stock of what is known and what is needed to improve understanding of chronic wounds and their associated failure to heal is crucial to ensuring better treatments and outcomes.

Effect of Micropower Vacuum Dressing on Promoting Wound Healing in Patients with I-II Diabetic Foot

Objective

Discuss the effectiveness and value of micropower vacuum dressing (MVD) in promoting the healing of I-II grades diabetic foot wounds.

Methods

Sixty patients diagnosed with diabetic foot ulcers and Wagner grades I-II were selected and randomly divided into the control group and experimental group, with 30 cases in each group. The control group was covered with conventional treatments and petrolatum gauze dressings, and the experimental group was treated with MVD on the basis of conventional reatments. The therapeutic effects of the two groups were observed, including healing rate, ulcer area reduction rate, ulcer healing time, dressing change times, ulcer recurrence rate, adverse events, and so on.

Results

The healing rate (100%) of the experimental group was higher than that of the control group (56.7%); the wound reduction rate was higher than that of the control group (P < 0.05); the healing time, the number of dressing changes, and the 1-month recurrence rate were all low in the control group (P < 0.05). The incidence of adverse reactions in the experimental group (6.7%) was lower than that in the control group (46.7%) (P < 0.05).

Conclusion

MVD has significant effects in the treatment of I-II grades diabetic foot wounds and has few adverse reactions. It is an effective new method that can promote the growth of granulation tissue and epithelium and promote wound healing.

Negative pressure wound therapy: device design, indications, and the evidence supporting its use

Introduction: Negative pressure wound therapy (NPWT) has become a mainstay in the armamentarium for wound care. Since the initial commercial vacuum-assisted closure device became available in 1995, subsequent research has confirmed the positive physiological effects of negative pressure on wound healing. Traditionally, NPWT has been used to improve healing of open nonsurgical wounds by secondary intention. However, the clinical applications of NPWT have significantly broadened, and now also include use in open surgical wounds, closed surgical incisions, and skin graft surgery. In addition, devices have evolved and now include functionality and features such as instillation, antimicrobial sponges, and portability.Areas covered: This article reviews the history, background, and physiology underlying NPWT, as well as the most commonly used devices. In addition, an evidence-based discussion of the current clinical applications of NPWT is presented, with a focus on those with high levels of evidence.Expert opinion: Future directions for device development include modifications to increase ease of use by patients and to allow its use in a broader array of anatomic areas. Lastly, more research with high levels of evidence is needed to better define the outcomes associated with NPWT, including in relation to specific clinical applications and cost.

Negative pressure wound therapy promotes wound healing by suppressing macrophage inflammation in diabetic ulcers

Aim: This work aims to explore the biological role of negative pressure wound therapy (NPWT) in the treatment of diabetic ulcer. Materials & methods: Full-thickness skin defects were created in diabetic (db/db) and non diabetic (db/m) mice to create wound models. The mice were received NPWT or rapamycin injection. Mouse macrophage cells (Raw264.7) were treated with lipopolysaccharide to induce inflammatory response, and then received negative pressure treatment. We observed the wound healing of mice and examined gene and protein expression and CD68⁺ macrophage levels. Results: NPWT notably enhanced the wound closure ratio, and inhibited the LC3-II/LC3-I ratio and Beclin-1 expression in diabetes mellitus (DM) mice. NPWT decreased CD68⁺ macrophage levels in wound tissues of DM mice. The influence conferred by NPWT was abolished by rapamycin treatment. Negative pressure repressed the LC3-II/LC3-I ratio and the expression of Beclin-1, TNF-α, IL-6 and IL-1β in the Raw264.7 cells. Conclusion: NPWT promotes wound healing by suppressing autophagy and macrophage inflammation in DM.

Effect of Combining Low Temperature Plasma, Negative Pressure Wound Therapy, and Bone Marrow Mesenchymal Stem Cells on an Acute Skin Wound Healing Mouse Model

Low-temperature plasma (LTP; 3 min/day), negative pressure wound therapy (NPWT; 4 h/day), and bone marrow mesenchymal stem cells (MSCs; 1×106 cells/day) were used as mono- and combination therapy in an acute excisional skin wound-healing ICR mouse model. These therapies have been beneficial in treating wounds. We investigated the effectiveness of monotherapy with LTP, NPWT, and MSC and combination therapy with LTP + MSC, LTP + NPWT, NPWT + MSC, and LTP + NPWT + MSC on skin wounds in mice for seven consecutive days. Gene expression, protein expression, and epithelial thickness were analyzed using real time polymerase chain reaction (RT-qPCR), western blotting, and hematoxylin and eosin staining (H&E), respectively. Wound closure was also evaluated. Wound closure was significantly accelerated in monotherapy groups, whereas more accelerated in combination therapy groups. Tumor necrosis factor-α (TNF-α) expression was increased in the LTP monotherapy group but decreased in the NPWT, MSC, and combination therapy groups. Expressions of vascular endothelial growth factor (VEGF), α-smooth muscle actin (α-SMA), and type I collagen were increased in the combination therapy groups. Re-epithelialization was also considerably accelerated in combination therapy groups. Our findings suggest that combination therapy with LPT, NPWT, and MSC exert a synergistic effect on wound healing, representing a promising strategy for the treatment of acute wounds.

Regeneration and Repair of Skin Wounds: Various Strategies for Treatment

Skin as a mechanical barrier between the inner and outer environment of our body protects us against infection and electrolyte loss. This organ consists of 3 layers: the epidermis, dermis, and hypodermis. Any disruption in the integrity of skin leads to the formation of wounds, which are divided into 2 main categories: acute wounds and chronic wounds. Generally, acute wounds heal relatively faster. In contrast to acute wounds, closure of chronic wounds is delayed by 3 months after the initial insult. Treatment of chronic wounds has been one of the most challenging issues in the field of regenerative medicine, promoting scientists to develop various therapeutic strategies for a fast, qualified, and most cost-effective treatment modality. Here, we reviewed more recent approaches, including the development of stem cell therapy, tissue-engineered skin substitutes, and skin equivalents, for the healing of complex wounds.

Treatment of large avulsion injury in perianal, sacral, and perineal regions by island flaps or skin graft combined with vacuum assisted closure

BACKGROUND

Traumatic avulsion injuries to the anus, although uncommon, can result in serious complications and even death. Management of anal avulsion injuries remains controversial and challenging. This study aimed to investigate the clinical effects of treating large skin and subcutaneous tissue avulsion injuries in the perianal, sacral, and perineal regions with island flaps or skin graft combined with vacuum assisted closure.

METHODS

Island flaps or skin graft combined with vacuum assisted closure, diverting ileostomy, the rectum packed with double-lumen tubes around Vaseline gauze, negative pressure drainage with continuous distal washing, wounds with skin grafting as well as specialized treatment were performed.

RESULTS

The injuries healed in all patients. Six cases had incomplete perianal avulsion without wound infection. Wound infection was seen in four cases with annular perianal avulsion and was controlled, and the separated prowl lacuna was closed. The survival rate in 10 patients who underwent skin grafting was higher than 90%. No anal stenosis was observed after surgery, and ileostomy closure was performed at 3 months (six cases) and 6 months (four cases) after surgery, respectively.

CONCLUSIONS

Covering a wound with an island flap or skin graft combined with vacuum assisted closure is successful in solving technical problems, protects the function of the anus and rapidly seals the wound at the same time.

Autologous platelet-rich gel treatment for diabetic chronic cutaneous ulcers: A meta-analysis of randomized controlled trials

BACKGROUND

In recent years, many studies have reported that autologous platelet-rich gel (APG) is an effective adjuvant treatment for chronic cutaneous ulcers in diabetics. The aim of this study was to explore the efficacy and safety of APG for the topical treatment of diabetic chronic cutaneous ulcers.

METHODS

The China Biology Medicine (CBM), China National Knowledge Infrastructure (CNKI), VIP Database for Chinese Technical Periodicals (VIP), Chinese Wanfang database, PubMed, EMBASE, EBSCOhost, and Cochrane Library were systematically searched for relevant studies published up to 18 October 2017. Fixed- and random-effects models were used to calculate risk ratios (RR), odds ratios (ORs), and mean difference (MD) with 95% confidence intervals (95% CI). Subgroup analyses were conducted according to the Diabetic Foot Wagner Classification.

RESULTS

Fifteen randomized control trials (RCTs) with 829 patients were eligible for inclusion in this analysis. Compared with standard care or conventional treatment, APG significantly improved the healing rate (RR 1.39; 95% CI 1.29, 1.50; P < 0.00001), shortened the healing time (MD -9.18; 95% CI -11.32, -7.05; P < 0.00001), and reduced the incidence of infection (OR 0.34; 95% CI 0.15, 0.77; P = 0.009).

CONCLUSIONS

Current evidence suggests that APG is effective and safe, and is feasible for use as an adjuvant treatment for diabetic ulcers, especially chronic refractory ulcers. However, more RCTs with a good design and of a high quality are needed before the use of APG can be implemented widely.

Treatment of human chronic wounds with autologous extracellular matrix/stromal vascular fraction gel: A STROBE-compliant study

Stem cell therapy is considered as the most promising treatment for chronic wounds. Extracellular matrix/stromal vascular fraction gel (ECM/SVF gel), an adipose-derived stem cell-based cytotherapy, has shown healing potential in experimental wounds in animal models. However, the effects of ECM/SVF gel on human chronic wounds have not been investigated. The aim of the present study is to investigate the therapeutic effect of ECM/SVF gel on human chronic wounds.Autologous ECM/SVF gel was prepared and used to treat patients with chronic wounds in clinics, with negative pressure wound therapy as the positive control. Wound healing rate per week and histological changes were performed.The average wound healing rate per week in the ECM/SVF gel group was 34.55 ± 11.18% compared with 10.16 ± 2.67% in the negative pressure wound therapy group (P < .001). Histological analysis with hematoxylin and eosin, Masson's trichrome staining, and CD31 immunohistochemistry showed less lymphocyte infiltration, more collagen accumulation, and more newly formed vessels in the ECM/SVF gel group treated skins compared to the control.ECM/SVF gel is an effective therapeutic option for chronic wound healing in clinics.

Reduction of diabetic foot ulcer healing times through use of advanced treatment modalities

Diabetic wounds are a major health care problem associated with delayed healing and high amputation rates. This review systematically evaluated newer wound care therapies for the treatment of diabetic wounds. More recent means of approaching diabetic foot ulcers include various dressings, off-loading shoes, and bioengineered skin constructs and growth factors. Electrical stimulation, phototherapy, electromagnetic fields, and shockwave therapy have been further proposed as potential treatments. A brief overview of these treatments is presented using peer-reviewed evidenced-based literature. A review of the literature demonstrated that treatment of diabetic wounds has focused on either prevention of the wounds in the form of off-loading shoes or adequate protective dressings or on direct treatment of wounds with bioengineered skin constructs, growth factors, or medical devices that accelerate wound healing. The authors' conclusion, following extensive literature review, is that although excellent national and international guidelines exist regarding suggested approaches to the treatment of the diabetic foot ulcer, there is no definitive or universal consensus on the choice of specific treatment modalities. The importance of optimizing comorbidities and the disease state, hemodynamics, local and peripheral skin and wound care, and metabolic challenges while reducing biological and bacterial burden and minimizing trauma remain the primary approach, followed by choice of the most appropriate treatment material or product.

Cyclic negative pressure wound therapy: an alternative mode to intermittent system

The purpose of this study was to develop and test a novel mode of negative pressure wound therapy (NPWT) that minimises pain while preserving the efficacy in wound healing. A porcine model was used in this study. Wounds were generated in animals and treated with either simple dressing or various treatment modes of NPWT. The wound volume, perfusion level and vasculature status were analysed and compared among different groups. Clinical application was performed to evaluate the level of pain occurring when negative pressure is applied. Among the NPWT groups, the Cyclic-50 group showed most decrement in wound volume, even though statistical relevance was not found (P = 0·302). The perfusion level was significantly increased in the Cyclic-50 group compared with the Intermittent group (P < 0·001) and the Cyclic-100 group (P = 0·004). Evaluation of blood vessel formation revealed that the Cyclic-50 group showed the highest number of vasculature with statistical significance (P < 0·001). In clinical application, the cyclic group showed significant decrease in pain compared with the intermittent group (P = 0·001). The cyclic NPWT mode decreased patient discomfort while maintaining superior wound healing effects as the intermittent mode.