Negative Pressure Wound Therapy

Negative Pressure Wound Therapy for Chronic Wounds

ABSTRACT

Chronic wounds, including those caused by venous and arterial insufficiency, diabetic complications, and pressure-induced ulcers, pose significant treatment challenges. Negative pressure wound therapy has been increasingly used for managing these wounds. This treatment aims to promote wound healing, prepare the wound bed for further surgical intervention, minimize the risk of infection, and potentially shorten the time to wound healing. Considering variances in techniques applied in different regions globally, there is an emerging need to comprehensively evaluate the effectiveness of negative pressure wound therapy on chronic wounds. Unfortunately, detailed descriptions of the techniques applied to achieve negative pressure are often lacking in existing literature abstracts, posing challenges for direct comparisons. This review aims to analyze the application of negative pressure wound therapy in the treatment of chronic wounds, summarize its advantages and disadvantages, and further explore the potential value and future research direction of negative pressure wound therapy in the repair of chronic wounds.

Fatter Is Better: Boosting the Vascularization of Adipose Tissue Grafts

Adipose tissue resorption after fat grafting is a major drawback in plastic and reconstructive surgery, which is primarily caused by the insufficient blood perfusion of the grafts in the initial phase after transplantation. To overcome this problem, several promising strategies to boost the vascularization and, thus, increase survival rates of fat grafts have been developed in preclinical studies in recent years. These include the angiogenic stimulation of the grafts by growth factors and botulinum neurotoxin A, biologically active gels, and cellular enrichment, as well as the physical and pharmacological stimulation of the transplantation site. To transfer these approaches into future clinical practice, it will be necessary to establish standardized procedures for their safe application in humans. If this succeeds, the surgical outcomes of fat grafting may be markedly improved, resulting in a significant reduction of the physical and psychological stress for the patients.

Negative-Pressure Wound Therapy (NPWT) in Horses: A Scoping Review

Obtaining a healthy wound environment that is conductive to healing in horses can be challenging. Negative-pressure wound therapy (NPWT) has been employed in humans to enhance wound healing for decades. The existing evidence for the effectiveness of NPWT remains uncertain in equine medicine. The aim of this review is to investigate NPWT applications and benefits in horses. A scoping review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines for scoping reviews on three databases (PubMed, Web of Science-Thompson Reuters, and Wiley Online Library). Twenty-four manuscripts were considered. After removing duplicates, 17 papers underwent abstract screening. Of these, 16 + 1 (cited by others) were evaluated for eligibility according to PICOs, including no case reports/retrospective studies, four original articles, and three reviews. Fifteen manuscripts met the inclusion criteria. The focus of the articles was wound management; they included three reports of wounds communicating with synovial structures. Traumatic wounds and surgical-site infections are indications for NPWT. NPWT presents several advantages and few complications making it an attractive alternative to conventional wound management. However, randomized controlled trials should be performed to quantify the benefits and establish precise protocols in horses.

Negative pressure promotes macrophage M1 polarization after Mycobacterium tuberculosis infection via the lncRNA XIST/microRNA-125b-5p/A20/NF-κB axis

Experiments have demonstrated the regulation of long noncoding RNA (lncRNA) in tuberculosis (TB), and negative pressure treatment has been associated with the alleviation of TB. Here, we investigated the interaction of negative pressure and the lncRNA X-inactive specific transcript (XIST) in modulating Mycobacterium tuberculosis (MTB) infection. Initially, we established an in vitro cell model of MTB infection and an in vivo mouse model of MTB infection, followed by treatment with negative pressure. Then, we examined the expression of XIST, followed by analysis of the downstream miRNA of XIST. XIST was overexpressed or underexpressed through cell transfection to examine its effects on macrophage polarization via the miR-125b-5p/A2 axis. The MTB models were characterized by upregulated XIST and downregulated miR-125b-5p. XIST bound to miR-125b-5p, leading to its downregulation, and thus causing higher MTB survival in an ESAT-6-dependent manner. Additionally, negative pressure treatment decreased MTB-driven XIST expression through downregulation of A20 (an NF-κB repressor) via miR-125b-5 expression, promoting the M1 polarization program in macrophages through activation of the NF-κB pathway. In summary, negative pressure treatment after MTB infection can promote the polarization of macrophages to the proinflammatory M1 phenotype by regulating the XIST/miR-125b-5p/A20/NF-κB axis.

Triboelectric Nanogenerators for Self-Powered Wound Healing

Wound healing, one of the most complex processes in the human body, involves the spatial and temporal synchronization of a variety of cell types with distinct roles. Slow or nonhealing skin wounds have potentially life-threatening consequences, ranging from infection to scar, clot, and hemorrhage. Recently, the advent of triboelectric nanogenerators (TENGs) has brought about a plethora of self-powered wound healing opportunities, owing to their pertinent features, including wide range choices of constitutive biocompatible materials, simple fabrication, portable size, high output power, and low cost. Herein, a comprehensive review of TENGs as an emerging biotechnology for wound healing applications is presented and covered from three unique aspects: electrical stimulation, antibacterial activity, and drug delivery. To provide a broader context of TENGs applicable to wound healing applications, state-of-the-art designs are presented and discussed in each section. Although some challenges remain, TENGs are proving to be a promising platform for human-centric therapeutics in the era of Internet of Things. Consequently, TENGs for wound healing are expected to provide a new solution in wound management and play an essential role in the future of point-of-care interventions.

Electrospun nanofibers promote wound healing: theories, techniques, and perspectives

At present, the clinical strategies for treating chronic wounds are limited, especially when it comes to pain relief and rapid wound healing. Therefore, there is an urgent need to develop alternative treatment methods. This paper provides a systematic review on recent researches on how electrospun nanofiber scaffolds promote wound healing and how the electrospinning technology has been used for fabricating multi-dimensional, multi-pore and multi-functional nanofiber scaffolds that have greatly promoted the development of wound healing dressings. First, we provide a review on the four stages of wound healing, which is followed by a discussion on the evolvement of the electrospinning technology, what is involved in electrospinning devices, and factors affecting the electrospinning process. Finally, we present the possible mechanisms of electrospun nanofibers to promote wound healing, the classification of electrospun polymers, cell infiltration favoring fiber scaffolds, antibacterial fiber scaffolds, and future multi-functional scaffolds. Although nanofiber scaffolds have made great progress as a type of multi-functional biomaterial, major challenges still remain for commercializing them in a way that fully meets the needs of patients.

Clinical experience of biliary T tube of immobilization of peri-pin membrane in tibial Gustilo III fracture treated with vacuum sealant drainage combined with an external fixator

OBJECTIVE

To determine the effects of an improved method of peri-pin membrane immobilization in tibial Gustilo type III fracture treated with vacuum sealant drainage (VSD) combined with an external fixator.

METHOD

A biliary T tube of suitable size and type was cut into a certain long arm and cross arm which wrapping around a pin to improving traditional peri-pin VSD method. Eighty-six cases of Gustilo type III tibial fracture admitted from January 2016 to December 2019 were prospectively treated, of which 43 cases were treated using a traditional method of VSD (Traditional group) and 43 cases in which VSD treatment was enhanced (Improved group). The 2 groups were compared by some clinical indexes. Statistical software was then used for data analysis. P < .05 was considered statistically significant.

RESULTS

Compared with the Traditional group, the improved group significantly reduced granulation tissue growth time (day) (7.35 + 2.59 vs 11.14 + 2.54, P < .05), antibiotic use time (day) (6.67 + 2.39 vs 8.70 + 1.98, P < .05), operation time (min) (72.44 + 16.79 vs 85.47 + 17.44, P < .05) duration of hospital stay (day) (18.23 + 5.04 vs 21.53 + 4.79, P < .05), wound closure time (day) (9.23 + 2.69 vs 14.19 + 2.67, P < .05), air leakage around the fixed needle (3/43 vs 16/43, P < .05) and postoperative pain score (P < .05). Meanwhile, the white blood cell, C-reactive protein, erythrocyte sedimentation rate of 1 week and 2 weeks post-operation were also reduced after adopting the improved method (P < .05). The difference in infection around the fixation pin and pin loosening between the 2 groups was not significant.

CONCLUSION

The biliary T tube was effctive in improving VSD combined with external fixation for the treatment of tibial Gustilo type III fractures. The materials are easy to obtain and straightforward to use and so is worthy of clinical promotion.

Seed skin grafts for reconstruction of distal limb defects in 15 dogs

OBJECTIVES

To report the surgical technique of seed skin grafting and clinical application for reconstruction of wounds on the distal limb of client-owned dogs.

MATERIALS AND METHODS

Medical records from The Animal Hospital at Murdoch University were retrospectively reviewed for dogs requiring reconstruction using seed grafting for distal limb skin defects between January 2009 and May 2020.

RESULTS

Fifteen dogs were included. Grafting was performed on distal limb wounds at or below the carpus or tarsus, following trauma (n = 12) or neoplasia excision (n = 3). Complete epithelialisation with minimal contracture was recorded at a median of 4 weeks (range 3 to 8 weeks) after implantation. Median follow-up was 37 months (range 3 to 55 months) after grafting. Postoperative complications included epidermal inclusion cyst in two dogs. Good functional outcome with acceptable cosmesis despite sparse hair growth was achieved in all cases.

CLINICAL SIGNIFICANCE

Seed grafting is a simple technique that can be used reliably to reconstruct wounds on the distal limb in dogs where other reconstructive techniques are not suitable. Complete epithelialisation with sparse hair growth, good long-term functional outcome and minimal complications can be expected.

Technological Advances in Wound Treatment of Exotic Pets

Although most research about the use of technological advances for wound healing was performed in laboratory animals but oriented to human medicine, recent technological advances allowed its application not only to small animals but also to exotic pets. This article reviews the literature available about some of these techniques (negative wound pressure therapy, photobiomodulation [laser therapy], electrical stimulation therapy, therapeutic ultrasonography, hyperbaric oxygen therapy), and other advances in wound management (skin expanders, xenografts, and bioengineered autologous skin substitutes) in exotic pet species.

Reconstruction of Pelvic Exenteration Defects Using the Combined Method With Extended Vertical Rectus Abdominus Flap and Vacuum-Assisted Suction Drainage

Introduction:

Pelvic exenteration is a highly invasive procedure, with a reported rate of 20%–80% for serious complications. Thus, the prevention of postoperative complications is a major issue. Many previous reports have emphasized the importance of filling the dead space to prevent postoperative complications. In addition to filling the dead space, we believe that achieving sufficient drainage is extremely important. In this paper, we present a new combined method of the extended rectus abdominis myocutaneous flap and vacuum drainage with multiple drains, which achieved a lower frequency of complications.

Case Presentation:

The subjects were 6 patients who underwent reconstruction following pelvic exenteration during a 7-year period between April 2005 and September 2013. We retrospectively measured the volume of the pelvic cavity and that of the rectus abdominis flap on lateral computed tomography (CT) scans to calculate the percentage of the dead space that was filled by the flap. There were no problems with flap engraftment in any of the patients. There were no serious complications, and no patient required additional surgery. The percentage of the dead space filled ranged from 25% to 46% (mean: 32%).

Conclusion:

The rectus flap + vacuum drainage method, which uses an extended rectus abdominis myocutaneous flap to decrease the pelvic dead space and multiple vacuum suction drains, was associated with the prevention of serious complications.

Wound Management: Wounds with Special Challenges

Distal limb wounds in horses heal substantially different than trunk wounds, commonly resulting in exuberant granulation tissue and exposed and sequestered bone. Surgical intervention of severe rectovaginal lacerations in the mare should be delayed until the tissues have heeled and scar tissue has remodeled. Wounds resulting in severe hemorrhage require appropriate emergent fluid therapy and potentially transfusion therapy.

Surface engineering of spongy bacterial cellulose via constructing crossed groove/column micropattern by low-energy CO2 laser photolithography toward scar-free wound healing

Bacterial cellulose (BC) is a bio-derived polymer, and it has been considered as an excellent candidate material for tissue engineering. In this study, a crossed groove/column micropattern was constructed on spongy, porous BC using low-energy CO₂ laser photolithography. Applying the targeted immobilization of a tetrapeptide consisting of Arginine-Glycine-Aspartic acid-Serine (H-Arg-Gly-Asp-Ser-OH, RGDS) as a fibronectin onto the column platform surface, the resulting micropatterned BC (RGDS-MPBC) exhibited dual affinities to fibroblasts and collagen. Material characterization of RGDS-MPBC revealed that the micropattern was built by the column part with size of ~100 × 100 μm wide and ~100 μm deep, and the groove part with size of ~150 μm wide. Hydrating the MPBC did not result in the collapse of the integrity of the micropattern, suggesting its potential application in a highly hydrated wound environment. Cell culture assays revealed that the RGDS-MPBC exhibited an improved cytotoxicity to mouse fibroblasts L929, as compared to the pristine BC. Meanwhile, it was observed that the RGDS-MPBC was able to guide the ordered aggregation of human skin fibroblast (HSF) cells on the column platform surface, and no HSF cells were found in the groove channels. Over time, it was found that a dense network of collagen was gradually established across the groove channels. Furthermore, the in-vivo animal study preliminarily demonstrated the scar-free healing potential of the micropatterned BC materials. Therefore, this RGDS-MPBC material exhibited its advantages in guiding cell migration and collagen distribution, which could present a prospect in the establishment of "basket-woven" organization of collagen in normal skin tissue against the formation of dense, parallel aggregation of collagen fibers in scar tissue toward scar-free wound healing outcome.