Negative Pressure Wound Therapy Treatment Research Articles

Negative Pressure Wound Therapy versus Conventional Dressing in Lower Limb Fractures: Systematic Review and Meta-analysis.

Gustilo 3 lower limb fractures represent a significant challenge because of high complication risk. Two management strategies are commonly used for wound coverage until final closure: negative pressure wound therapy (NPWT) and conventional wound dressing (CWD), also described as standard wound coverage without subatmospheric pressure. Understanding their relative effectiveness is essential to improve patient outcomes. The aim of this systematic review and meta-analysis was to compare the efficacy of NPWT and CWD in Gustilo 3 lower limb fracture management, with a focus on overall rates, superficial infection, and deep infection rates. A systematic review of medical research databases was conducted in accordance with PRISMA guidelines. Studies comparing NPWT with CWD for Gustilo 3 fractures were included. Data extraction and quality assessment were performed. Treatment with CWD was associated with significantly higher rates of overall infection [pooled risk ratio (RR): 0.33; 95% confidence interval (CI): 0.14-0.51] and pooled risk difference (RD: 0.27; 95% CI: 0.15-0.38), superficial infection (pooled RR: 0.35; 95% CI: 0.04-0.66), and deep infection (pooled RR: 0.20; 95% CI: 0.02-0.38) compared with NPWT treatment. Overall infection rate remained significantly higher in the CWD group after analyzing only open tibia fractures (pooled RR: 0.35; 95% CI: 0.21-0.48). Nonunion rate was significant higher in the CWD group (pooled RR: 0.30; 95% CI: 0.00-0.59). Flap failure rate was similar in both groups (pooled RR: 0.09; 95% CI: -0.05 to 0.23). NPWT appears to be a reasonable option for wound management in Gustilo 3 lower limb fractures in terms of infection rates.

Negative Pressure Wound Therapy-A Vacuum-Mediated Positive Pressure Wound Therapy and a Closer Look at the Role of the Laser Doppler.

Background: Negative pressure wound therapy (NPWT) is an intensely investigated topic, but its mechanism of action accounts for one of the least understood ones in the area of wound healing. Apart from a misleading nomenclature, by far the most used diagnostic tool to investigate NPWT, the laser Doppler, also has its weaknesses regarding the detection of changes in blood flow and velocity. The aim of the present study is to explain laser Doppler readings within the context of NPWT influence. Methods: The cutaneous microcirculation beneath an NPWT system of 10 healthy volunteers was assessed using two different laser Dopplers (O2C/Rad-97®). This was combined with an in vitro experiment simulating the compressing and displacing forces of NPWT on the arterial and venous system. Results: Using the O2C, a baseline value of 194 and 70 arbitrary units was measured for the flow and relative hemoglobin, respectively. There was an increase in flow to 230 arbitrary units (p = 0.09) when the NPWT device was switched on. No change was seen in the relative hemoglobin (p = 0.77). With the Rad-97®, a baseline of 92.91% and 0.17% was measured for the saturation and perfusion index, respectively. No significant change in saturation was noted during the NPWT treatment phase, but the perfusion index increased to 0.32% (p = 0.04). Applying NPWT compared to the arteriovenous-vessel model resulted in a 28 mm and 10 mm increase in the venous and arterial water column, respectively. Conclusions: We suspect the vacuum-mediated positive pressure of the NPWT results in a differential displacement of the venous and arterial blood column, with stronger displacement of the venous side. This ratio may explain the increased perfusion index of the laser Doppler. Our in vitro setup supports this finding as compressive forces on the bottom of two water columns within a manometer with different resistances results in unequal displacement.

Application of Staged Negative Pressure Wound Therapy and Flap Surgery for Infection Control After Patellar Internal Fixation Surgery.

The anatomic position of the patella is superficial, making it vulnerable to injuries. Treatment of patella infection after internal fixation surgery remains a big challenge due to minimal soft tissue coverage and vital tissue exposure. Forty-two patients aged 10 to 59 years were admitted to the institution's burn unit between January 2010 and December 2019. Each presented with infection after patellar fracture surgery. Twenty-seven infections were superficial, whereas 15 were deep with pyogenous arthritis of the knee. Negative pressure wound therapy (NPWT) was applied after radical debridement to remove necrotic subcutaneous tissues and internal fixation devices. In addition, cases with septic arthritis were irrigated continuously with normal saline. After 5 to 10 days of NPWT treatment and irrigation, wound infection was well controlled. Afterward, 42 wounds were resurfaced with pedicled flaps, the 42 patients received 17 reverse-flow anterolateral thigh (ALT) perforator flap, 12 medial sural artery perforator flaps, 7 gastrocnemius musculocutaneous flaps, as well as 6 saphenous artery flaps. Thirty-seven flaps survived uneventfully. However, 3 flaps developed venous congestion in the distal end. Two flaps developed tip necrosis. All patients were followed up between 3 and 48 months. Infection beneath the flap occurred in 3 patients and healed after an additional debridement surgery. The staged NPWT and flap surgery strategy focus on thorough debridement and immediate internal fixation devices removal, effective fracture fixation, efficient NPWT application, targeted administration of antibiotics, and adequate soft tissue coverage. This study established that the procedure was effective in infection control after patellar internal fixation surgery.

Negative pressure wound therapy for flap closed-incisions after 3D-printed prosthesis implantation in patients with chronic osteomyelitis with soft tissue defects

BackgroundThe flap closed-incisions healing after 3D-printed prosthesis implantation in Chronic Osteomyelitis with Soft Tissue Defects (COSTD) is critical. This study aimed to explore the safety and effectiveness of Negative Pressure Wound Therapy (NPWT) in promoting flap closed-incisions healing.MethodsRetrospective analysis of clinical data was performed, including baseline, surgical and hospitalization information. The efficacy of NPWT was assessed by comparing the ASEPSIS scores, Visual Analogue Scale (VAS), Activity of Daily Living Scale (ADLS), and Lower Extremity Functional Scale (LEFS), as well as the major postoperative complications.ResultsThe study included 20 patients, 13 received conventional dressing (Control group) and 7 received NPWT treatment (NPWT group). These two groups exhibited a notable disparity in the distribution of ASEPSIS scores, and the median scores were 24 in Control group and 9 in NPWT group (p = 0.001). Eight patients in the Control group experienced major incisional complications, including 7 cases of exudation, 3 cases of infection, 2 cases of non-healing, and 1 case of dehiscence, while none were observed in the NPWT group (p = 0.015). The VAS, ADLS, and LEFS scores were significantly improved in the NPWT group compared to the Control group (p = 0.003, 0.017, and 0.043, respectively).ConclusionsThe study findings suggest that NPWT applied to the healing process of flap closed-incisions after 3D prosthesis implantation in patients with COSTD can reduce the occurrence of postoperative major complications and promote the recovery of lower limb function and daily activities, which should be recommended for clinical practice.

Treatment of Complex Thoracic and Abdominal Trauma Patients: A Review of Literature and Negative Pressure Wound Therapy Treatment Options.

Significance: In trauma care, extensive surgical intervention may be required. Damage control surgery (DCS) is applicable to patients with life or limb-threatening conditions that are incapable of tolerating a traditional surgical approach. Recent Advances: The current resuscitation strategy for complex trauma patients includes limiting crystalloid fluids, balanced mass transfusion protocols, permissive hypotension, and damage control resuscitation. Recent technological advancements in surgical critical care have improved outcomes in these critically ill patients. Critical Issues: DCS, which is often required in patients with trauma injuries, is typically followed by surgical correction of the injury once the immediate patient survival procedures have been completed. However, DCS and the subsequent injury repair procedures have a high risk for postsurgical complication development. Future Directions: Negative pressure therapy modalities can offer clinicians additional adjunctive and cost-effective tools for the management of the trauma care patient, as these systems can be utilized during both the DCS and the postoperative injury management phases of trauma care.

Negative pressure wound therapy: A salvage solution for wound treatment with exposed bone tissue

Negative pressure wound therapy (NPWT) is a well-known and proven treatment for wound care. However, its use on bone tissue hasn’t been described so far. Wounds with visible bone tissue are difficult to manage and the results are often disappointing. We describe the case of a 75-year-old man, with cutaneous necrosis and underlying exposed hardware 7 weeks after a tibial shaft fracture treated by open reduction and internal fixation. After hardware removal, and because of the impossibility to close the soft tissue, a NPWT was directly applied to the bone. The results were encouraging, and a simple skin graft was sufficient after NPWT treatment. Through this case and after a review of the literature, it seems appropriate to extend the indications of NPWT as a salvage solution for exposed bone wound. Further studies are needed to determine the limits of this therapeutic option and to compare it with the already existing treatments.

Novel cell culture system for monitoring cells during continuous and variable negative-pressure wound therapy.

Although the clinical efficacy of negative-pressure wound therapy (NPWT) is well known, many of its molecular biological mechanisms remain unresolved, mainly due to the difficulty and paucity of relevant in vitro studies. We attempted to develop an in vitro cell culture system capable of real-time monitoring of cells during NPWT treatment. A novel negative-pressure cell culture system was developed by combining an inverted microscope, a stage-top incubator, a sealed metal chamber for cell culture, and an NPWT treatment device. Human keratinocytes, PSVK-1, were divided into ambient pressure (AP), continuous negative-pressure (NPc), and intermittent negative-pressure (NPi) groups and cultured for 24h with scratch assay using our real-time monitoring system and device. Pressure inside the device, medium evaporation rate, and the residual wound area were compared across the groups. Pressure in the device was maintained at almost the same value as set in all groups. Medium evaporation rate was significantly higher in the NPi group than in the other two groups; however, it had negligible effect on cell culture. Residual wound area after 9h evaluated by the scratch assay was significantly smaller in the NPc and NPi groups than in the AP group. We developed a negative-pressure cell culture device that enables negative-pressure cell culture under conditions similar to those used in clinical practice and is able to monitor cells under NPWT. Further experiments using this device would provide high-quality molecular biological evidence for NPWT.

Negative-Pressure Wound Therapy Induces Lymphangiogenesis in Murine Diabetic Wound Healing.

Decreased lymphangiogenesis contributes to impaired diabetic wound healing. Although negative-pressure wound therapy (NPWT) has been shown to be effective in the treatment of recalcitrant wounds, its impact on lymphangiogenesis remains to be elucidated. In this study, the authors investigate the mechanisms of lymphangiogenesis following NPWT treatment of diabetic murine wound healing. Full-thickness dorsal skin wounds (1 × 1 cm 2 ) were excised on 30 db/db mice. The mice were either treated with occlusive covering (control group, n = 15), or received a 7-day treatment of continuous NPWT at -125 mmHg (NPWT group, n = 15). The wounds were photographed on days 0, 7, 10, 14, 21, and 28. Wound tissue was harvested on days 10, 14, 21, and 28 for quantitative analysis. Functional analysis of lymphatic drainage was performed on days 14 and 28 with Evans blue dye tracing. Lymphatic density and diameter, as visualized through podoplanin probing, was significantly higher in the NPWT group compared to the control group ( P < 0.001). NPWT up-regulated the expression of lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) at the protein level ( P = 0.04), and significant differences were noted in lymphatic density as assessed by LYVE-1 staining ( P = 0.001). Leukocyte infiltration was significantly higher in the NPWT group ( P = 0.01). A higher speed of wound closure ( P < 0.0001) and greater wound bed thickness ( P < 0.0001) were noted in the NPWT group compared to the control group. NPWT increased the lymphatic vessel density and diameter with LYVE-1 up-regulation. NPWT therefore plays a positive role in lymphangiogenesis in diabetic wound healing. The authors' study investigates the association of NPWT and lymphatics and underlines the importance of a more in-depth investigation of the role of lymphatic vessels in wound healing.

Negative Pressure Wound Therapy Promotes Wound Healing by Inhibiting Inflammation in Diabetic Foot Wounds: A Role for NOD1 Receptor.

Aims: Diabetic foot results in frequent amputation and quality-of-life reduction in diabetes population. These lesions are featured by a prolonged and exaggerated inflammation with a significant impairment in local bacterial invasion. Negative pressure wound therapy (NPWT) attenuates hyperinflammation in the healing of diabetic foot wounds, but the potential mechanism of NPWT down-regulated inflammatory reaction still remains elusive. This study aims to explore the inflammatory signaling involved in the effect of NPWT on diabetic ulcer. Methods: Thirty patients with diabetic foot ulceration were divided into NPWT group (treated with NPWT, n = 10), NPWT + FK565 group (treated with NPWT combined with FK565 which is NOD1 receptor ligand, n = 10) and control group (n = 10). After two weeks treatment, samples were harvested and analyzed by histochemistry for infiltration of inflammatory cells, immunofluorescence stain for NOD1, western blotting for NOD1, RIP2 (Receptor interacting protein 2), IL-1β, TAK1 (Transforming growth factor-β-activated kinase1), p65 and real time-PCR for expression of NOD1 and RIP2. Results: NPWT could notably accelerate the diabetic wound healing through alleviating inflammatory reaction. The immunofluorescence analysis results revealed that NOD1 was mainly expressed in the cytoplasm and noticeably decreased after the NPWT treatment. And NPWT obviously decreased both the mRNA and protein level of NOD1 and RIP2. Moreover, The protein expression of IL-1β, TAK1 and p65 in the NPWT-group were significant decreased. Conclusion: NPWT effectively promotes wound healing by suppressing the wound inflammation in diabetic foot, which is mediated at least in part by suppression of NOD1 receptor.

Negative pressure wound therapy with intermittent irrigation for treatment of post-traumatic giant abscess: A case report.

IntroductionNegative pressure wound therapy (NPWT), also called vacuum-assisted closure, is an adjunctive therapy used to manage open wounds that apply subatmospheric pressure to the wound surface. The therapeutic effects of NPWT are exerted by stabilizing the wound environment, increasing blood flow, and macro-deformation of wounds that initiate granulation tissue formation.Case presentationWe present a case of a 28-year-old Caucasian male who developed a giant non-resolving hepatic abscess secondary to a gunshot wound (GSW) to the upper right abdomen. The abscess was successfully treated with open debridement followed by NWPT with instillation therapy. Significant reduction in abscess diameter and cessation of trauma-induced bile leak was observed following 15 days of wound vac treatment.DiscussionWound vac treatment was essential in this patient due to the inherent erosive properties of bile that damage surrounding tissue and perpetuate opportunistic growth of pathogenic microbes. Prior to standard NPWT treatment, debridement of devitalized tissues and infection should be managed; however, instillation therapy has permitted NPWT to be used in the presence of infection or as an adjuvant to surgical infection management.ConclusionNPWT is indicated for a wide range of acute and chronic wounds; however, the utilization of NPWT to treat abscesses remains unclear.

The effect of NPWT in wound healing and bacterial count on deep dermal burn injury model: An experimental study

BackgroundSepsis is one of the main causes in burn victim's mortality. The use of negative pressure wound therapy (NPWT) provides an ideal environment to accelerate wound healing. We compare the use of normal saline (NS), intermittent NPWT, continuous NPWT and silver sulfadiazine in wound healing process. MethodThis study involved 6 Yorkshire pigs; each pig was induced with 20 burns on the flank area. Burns were divided into 4 treatment groups: NS gauze, intermittent NPWT, continuous NPWT, and silver sulfadiazine dressing. Burns were evaluated on day 1,3,7,14, and 21 for its morphology and bacterial colonization and on day 14 and 21 for the remaining burn surface area. ResultWound that received NPWT therapy appeared better in both granulation and crust formation. Remaining burn surface area (mm2) on day 14 in NS group, intermittent NPWT, continuous NPWT, and silver sulfadiazine were 107.43 ± 83.43, 178.07 ± 74.83, 146.10 ± 69.1, 126.03 ± 83.22, respectively(p = 0.457); on day 21 in NS group, intermittent NPWT, continuous NPWT, and silver sulfadiazine were 13.16 ± 16.86, 59.49 ± 20.72, 54.79 ± 46.59, 48.95 ± 39.84, respectively(p=0.169). There were no significant differences in each treatment group bacterial colonization(p>0.05). There were no significant correlation between bacterial colonization and remaining burn surface area (p>0.05). ConclusionWhile morphologically, the wound in NPWT treatment groups appeared better in granulation and crust formation, the remaining wound surface area and the number of bacterial colonization were not significantly difference compared to standard therapy (silver sulfadiazine and NS gauze). There were no significant correlation between the amount of bacterial colonization and remaining wound surface area on every treatment group.

Negative pressure wound therapy improves bone regeneration by promoting osteogenic differentiation via the AMPK-ULK1-autophagy axis

ABSTRACT Deficient bone regeneration causes bone defects or nonunion in a substantial proportion of trauma patients that urges for novel therapies. To develop a reliable therapy, we investigated the effect of negative pressure wound therapy (NPWT) on bone regeneration in vivo in a rat calvarial defect model. Negative pressure (NP) treatment in vitro was mimicked to test its effect on osteoblast differentiation in rat mesenchymal stem cells (MSCs) and MC3T3-E1 cells. Transcriptomic analyses, pharmaceutical interventions, and shRNA knockdowns were conducted to explore the underlying mechanism and their clinical relevance was investigated in samples from patients with nonunion. The potential application of a combined therapy of MSCs in hydrogels with negative pressure was tested in the rat critical-size calvarial defect model. We found that NPWT promoted bone regeneration in vivo and NP treatment induced osteoblast differentiation in vitro. NP induced osteogenesis via activating macroautophagy/autophagy by AMPK-ULK1 signaling that was impaired in clinical samples from patients with nonunion. More importantly, the combined therapy involving MSCs in hydrogels with negative pressure significantly improved bone regeneration in rat critical-size calvarial defect model. Thus, our study identifies a novel AMPK-ULK1-autophagy axis by which negative pressure promotes osteoblast differentiation of MSCs and bone regeneration. NPWT treatment can potentially be adopted for therapy of bone defects. Abbreviations: ADP, adenosine diphosphate; AICAR/Aic, acadesine; ALP, alkaline phosphatase; ALPL, alkaline phosphatase, biomineralization associated; AMP, adenosine monophosphate; AMPK, AMP-activated protein kinase; ARS, alizarin red S staining; ATG7, autophagy related 7; ATP, adenosine triphosphate; BA1, bafilomycin A1; BGLAP/OCN, bone gamma-carboxyglutamate protein; BL, BL-918; BS, bone surface; BS/TV, bone surface per tissue volume; BV/TV, bone volume per tissue volume; C.C, compound C; CCN1, cellular communication network factor 1; COL1A1, collagen type I alpha 1 chain; COL4A3, collagen type IV alpha 3 chain; COL4A4, collagen type IV alpha 4 chain; COL18A1, collagen type XVIII alpha 1 chain; CQ, chloroquine; GelMA, gelatin methacryloyl hydrogel; GO, Gene Ontology; GSEA, gene set enrichment analysis; HIF1A, hypoxia inducible factor 1 subunit alpha; HPLC, high-performance liquid chromatography; ITGAM/CD11B, integrin subunit alpha M; ITGAX/CD11C, integrin subunit alpha X; ITGB1/CdD9, integrin subunit beta 1; KEGG, Kyoto Encyclopedia of Genes and Genomes; MAP1LC3B/LC3B, microtubule associated protein 1 light chain 3 beta; micro-CT, microcomputed tomography; MSCs, mesenchymal stem cells; MTOR, mechanistic target of rapamycin kinase; NP, negative pressure; NPWT, negative pressure wound therapy; PRKAA1/AMPKα1, protein kinase AMP-activated catalytic subunit alpha 1; PRKAA2, protein kinase AMP-activated catalytic subunit alpha 2; PTPRC/CD45, protein tyrosine phosphatase receptor type C; ROS, reactive oxygen species; RUNX2, RUNX family transcription factor 2; SBI, SBI-0206965; SPP1/OPN, secreted phosphoprotein 1; THY1/CD90, Thy-1 cell surface antigen; SQSTM1, sequestosome 1; TGFB3, transforming growth factor beta 3; ULK1/Atg1, unc-51 like autophagy activating kinase 1.

Clinical effects of negative pressure wound therapy in treating the poor healing of incisions after different abdominal operations

Objective: To investigate the clinical effects of negative pressure wound therapy (NPWT) in treating the poor healing of incisions after different abdominal operations. Methods: The retrospective observational study was conducted. From June 2019 to December 2020, 42 patients with poor healing of incisions after abdominal surgery were admitted to Center of Burns and Trauma of the First Affiliated Hospital of Naval Medical University, including 29 males and 13 females, aged 23-81 years. The disease course of poor healing of abdominal incision was 3-60 d. The preoperative examination of patients was completed after admission, and NPWT was used after debridement. According to the dehiscence level of incision, the negative pressure value of -10.64 to -6.65 kPa was set. The incisions were sutured in the second stage when the incisions had good blood circulation. The cause of abdominal surgery, the dehiscence level and the cause of poor healing of abdominal incision were investigated, and the final healing of abdominal incision and the occurrence of complication were observed. Results: The causes of abdominal operations in this group of patients who ocurred poor healing of abdominal incisions were ranked according to the composition ratio, with the top 4 causes being colon cancer (9 cases, accounting for 21.4%), bile duct disease (8 cases, accounting for 19.0%), liver cancer (5 cases, accounting for 11.9%), and appendicitis (4 cases, accounting for 9.5%). There were 25 cases (59.5%) with dehiscence of abdominal incision in the deep fascia layer, and the other 17 cases (40.5%) with dehiscence of abdominal incision in the superficial fascia layer. The causes of poor healing of abdominal incision were ranked according to the composition ratio, with the top 3 causes being infection (24 cases, accounting for 57.1%), fat liquefaction (11 cases, accounting for 26.2%), and suture reaction (5 cases, accounting for 11.9%). The blood circulation in 40 patients was improved after being treated with NPWT, and the incisions were sutured in the second stage. The incisions healed well when the suture lines were removed in the second to third week. Intestinal fistula and bile leakage developed during the NPWT treatment, respectively in the other 2 patients, in which negative pressure equipment was removed subsequently, and the incisions healed after adequate drainage and conventional dressing changes. Conclusions: NPWT is effective in treating poor healing of abdominal incision after different abdominal surgeries. The clinicians need to comprehensively assess the patient's condition to determine when and how to use NPWT to avoid the occurrence of intestinal fistula, bile leakage, and other complications.

Comprehensive analysis of lncRNA and miRNA expression profiles and ceRNA network construction in negative pressure wound therapy.

BackgroundThis study aims to explore the molecular mechanism of negative pressure wound therapy (NPWT) at the transcriptome level through whole transcriptome sequencing and biometric analysis.MethodsA rat skin defect model was constructed and randomly divided into a NPWT group and a gauze group. The tissue in the center of the wound was used for whole transcriptome sequencing, and differentially expressed messenger RNAs (DEmRNAs), long noncoding RNAs (DElncRNAs), and microRNAs (DEmiRNAs) were identified between the two groups. Quantitative real time-polymerase chain reaction (qRT-PCR) analysis was used to verify the sequencing results. Functional enrichment analysis, pathway analysis, and protein-protein interaction (PPI) network analysis of DEmRNAs were conducted. Through bioinformatics analysis, a lncRNA-associated competing endogenous RNA (ceRNA) network was identified and constructed.ResultsWe detected 896 DEmRNAs, 1,471 DElncRNAs, and 20 DEmiRNAs between the two groups. qRT-PCR verified the sequencing results. Functional analysis showed that DEmRNAs were mainly enriched in immune system processes and the Notch signaling pathway. Protein tyrosine phosphatase receptor type C (PTPRC) and signal transducer and activator of transcription 1 (STAT1) were the central hub nodes in the PPI analysis. The ceRNA network contained 11 mRNAs, 15 lncRNAs, and 4 miRNAs.ConclusionsWe identified several DEmRNAs, DElncRNAs, and DEmiRNAs between the NPWT treatment group and the control group. These findings may provide new insights into the pathophysiological mechanism of NPWT and wound healing.

Ultraviolet-A Light and Negative-Pressure Wound Therapy to Accelerate Wound Healing and Reduce Bacterial Proliferation.

Ultraviolet (UV)-A therapy is a simple, inexpensive, and effective modality for wound healing, with tremendous potential to improve healing and reduce clinical infections in a number of clinical settings. To date, application of UV-A relies on bulky and hard-to-dose lamps that provide inconsistent therapy, thus making it difficult to apply therapy that is appropriate for the patient. This study was designed to test the effectiveness of a novel wound therapy device that combines UV-A with traditional negative-pressure wound therapy (NPWT) to promote wound healing. Furthermore, we tested the ability of fiberoptic UV-A delivery to inhibit bacterial proliferation. Finally, we assayed the level of DNA damage that results from UV-A as compared to established UV-C therapies. Wound healing studies were performed in a porcine model using an articulated therapy arm that allows for continued therapy administration over an extended time course. Negative-pressure wound therapy was administered alone or with UV-A fiberoptic therapy for 2 weeks. Dressings were changed twice a week, at which time wound area was assessed. Data demonstrate that UV-A with NPWT treatment of wounds results in greater healing than NPWT alone. Using the same therapy device, we demonstrate that exposure of Staphylococcus aureus and Pseudomonas aeruginosa to fiberoptic UV-A results in decreased colony area and number of both bacterial strains. Finally, we show that UV-A induces minimal DNA damage in human fibroblasts and no more DNA damage in wound tissue as compare to intact skin. These data demonstrate that UV-A can decrease bacterial proliferation and promote wound healing when coupled with NPWT.

Effects of negative pressure wound therapy on an axial congested rabbit skin flap model without any bare surface

One of the most important problems encountered in reconstructive surgery is partial or total flap loss, and venous congestion is the most common reason. It should be solved as early as possible. The purpose of this study is to investigate the effects of Negative pressure wound therapy (NPWT) on an ideal congested rabbit skin flap model without any open wound. The current study included 28 female, adult, New Zealand albino rabbits. Animals were divided into four groups according to the duration of NPWT to be applied. An axial pattern ideal congested skin flap was designed on the posterior surface of the ear. After surgical intervention on the right ears, we applied NPWT treatment for 2, 4, 6 and 8 days. The left ears were followed without any treatment. Samples were taken for edema, congestion and neo-angiogenesis examination. There was no significant difference between the NPWT applied group and control group in the 2nd, 4th, 6th, and 8th days for edema and neo-angiogenesis and no differences in the 2nd, 6th, and 8th days for congestion. NPWT group had a higher flap survival rate than the control group but without a significant difference. This study used an ideal congested rabbit skin flap model imitating venous congestion. Our findings illustrate that NPWT treatment does not have a significant effect on the congested skin flap model we utilized where a closed system was created maintaining a skin barrier without a bare surface of the flap. Level of Evidence: Level I, experimental study

Negative pressure wound therapy enhances bone regeneration compared with conventional therapy in a rabbit radius gap-healing model.

Negative pressure wound therapy (NPWT) has been recognized as an effective method for the treatment of intractable wounds. However, its effects on bone healing remain to be elucidated. Our previous study demonstrated that NPWT induced cell proliferation and osteoblastic differentiation of rat periosteum-derived mesenchymal stem cells (P-MSCs). It was reported that following NPWT treatment, the expression of the mechanotransduction molecule integrin β5 is increased, indicating that NPWT may serve an active role in fracture healing by enhancing bone formation and reducing bone resorption. The present study sought to further investigate the efficacy of NPWT on the bone regeneration process in a rabbit radial gap-healing model. All rabbits with radial defects were randomly divided into two groups: NPWT and control groups. Continuous negative pressure at -125 mmHg was applied to all rabbits. Furthermore, X-ray imaging and scoring on day 7, 14, 21 and 28 postoperatively were performed to evaluate new bone formation. Histological changes were determined via hematoxylin and eosin and Masson's trichrome staining at 2- and 4-weeks following surgery. In addition, vimentin-positive cells located in the periosteum were detected via immunohistochemical examination on day 3 post operation. Finally, protein expression levels of vascular endothelial growth factor (VEGF), bone morphogenetic protein (BMP)-2 and osteopontin (OPN) were evaluated using western blot analysis on the 2nd and 4th week following NPWT. X-ray and histological examination revealed that the bone-healing processes in the NPWT group were faster compared with the control group. Additionally, compared with the control group, the NPWT group exhibited higher X-ray scores, increased percentage of positive vimentin-stained cells and upregulated expression of VEGF, BMP-2 and OPN proteins. The aforementioned findings suggest that NPWT, under a continuous negative pressure of -125 mmHg, may accelerate bone regeneration by enhancing MSC proliferation, osteoblastic differentiation and VEGF, BMP-2 and OPN expression.

Kiterjedt gluteális lokalizációjú hidradenitis suppurativa negatív nyomásterápiával kombinált többlépcsős sebészi ellátása

Hidradenitis suppurativa (HS) is a chronic, recurrent infammatory disease of the hair follicles in the skinfolds containing apocrine glands, which greatly impairs the quality of life of patients. The fnal solution in extensive cases is surgical treatment. There is no ideal treatment or uniform therapeutic template equally suitable for all patients. Treatment is personalized. In this paper, we present the case of a 53-year-old patient who underwent a two-stage surgical treatment for therapy-resistant HS, Hurley stage III, causing permanent complaints. During the frst surgery, the fstula openings were flled with methylene blue, then the skin and the scary subcutaneous tissue were excised, and after 10 days, in a second step, the surgical site was covered with split thickness skin graft from the back. After both surgeries, negative pressure wound therapy (NPWT) was initiated. After the applied treatment, 98-100% graft adhesion was observed, and the patient was emitted without complaints after 3 weeks. Our case illustrates that in cases where the prospects for fap replacement in HS are poor or the healing tendency of the faps is questionable (infective wound base, poor quality surrounding skin), split thickness skin grafting combined with negative pressure therapy may be less stressful and provides a successful outcome. The combined treatment (NPWT + split thickness skin graft) is excellent not only for clearing and stimulating the wound base, but also provides an excellent wound base and allows successful wound closure / coverage, signifcantly shortening the duration of the long and cumbersome open treatment has been used so far. In this case, NPWT treatment can also be considered as a “bridging” step.

Management of Deep Spinal Wound Infections Following Instrumentation Surgery with Subfascial Negative Pressure Wound Therapy.

The treatment of infections following a spine surgery continues to be a challenge. Negative pressure wound therapy (NPWT) has been an effective method in the context of infection therapy, and its use has gained popularity in recent decades. This study aims to analyze the impact of known risk factors for postoperative wound infection on the efficiency and length of NPWT therapy until healing. We analyzed 50 cases of NPWT treatment for deep wound infection after posterior and posteroanterior spinal fusion from March 2010 to July 2014 retrospectively. We included 32 women and 18 men with a mean age of 69 years (range, 36-87 years). Individual risk factors for postoperative infection, such as age, gender, obesity, diabetes, immunosuppression, duration of surgery, intraoperative blood loss, and previous surgeries, as well as type and onset (early vs. late) of the infection were analyzed. We assessed the associations between these risk factors and the number of revisions until wound healing. In 42 patients (84%), bacterial pathogens were successfully detected by means of intraoperative swabs and tissue samples during first revision. A total of 19 different pathogens could be identified with a preponderance of Staphylococcus epidermidis (21.4%) and S. aureus (19.0%). Methicillin-resistant S. aureus (MRSA) was recorded in two patients (2.6%). An average of four NPWT revisions was required until the infection was cured. Patients with infections caused by mixed pathogens required a significantly higher number of revisions (5.3 vs. 3.3; p < 0.01) until definitive wound healing. For the risk factors, no significant differences in the number of revisions could be demonstrated when compared with the patients without the respective risk factor. NPWT was an effective therapy for the treatment of wound infections after spinal fusion. All patients in the study had their infections successfully cured, and all spinal implants could be retained. The number of revisions was similar to those reported in the published literature. The present study provides insights regarding the effectiveness of NPWT for the treatment of deep wound infection after spinal fusion. Further investigations on the impact of potential risk factors for postoperative wound healing disorders are required. Better knowledge on the impact of specific risk factors will contribute to a higher effectiveness of prophylaxis for postoperative wound infections considering the patient-specific situation.

Associating Insulin Instillation with Negative Pressure Wound Therapy Reduces Insulin Resistance in Diabetic Patients with Infected Foot Wounds

In this work we investigated whether a joint treatment with insulin instillation and negative pressure wound therapy (NPWT) would reduce insulin resistance (IR) in diabetic patients with infected diabetic foot ulcers (DFUs) and improve their healing. We also studied the effects of insulin+NPWT treatment on the inflammatory response coupled with wound healing. Seventy-five diabetic patients with infected DFUs were recruited and randomly divided into equal (n=25) groups treated respectively with NPWT alone, NPWT+insulin, and conventional dressings (controls). Thereafter, the ulcers’ healing progress was assessed. The serum levels of Tumor Necrosis Factor-α (TNF-α), Interleukin-2 (IL-2), and Interleukin-6 (IL-6) were measured at 1 day before and at 7, 14, and 21 days after each treatment using specific double-antibody sandwich enzyme-linked immunosorbent assays (ELISA). Serum glucose was measured via a glucose-oxidase method, and serum insulin via radioimmunoassay. In each patient, IR was appraised via the Homeostasis Model Assessment (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI). Our results showed that at 7, 14 and 21 days post-treatment, with respect to the control group the two NPWT-treated groups had (i) significantly (p &lt; 0.05) lower serum levels of TNF-α, IL-2 and IL-6; (ii) a significantly (p &lt; 0.01) greater reduction in IR; and (iii) significantly (p &lt; 0.05) higher wound healing rates. Moreover, at 14- and 21-days post-treatment, the NPWT+insulin-treated group had a significantly (p &lt; 0.05) higher wound healing rate than the NPWT alone-treated group. In conclusion, the combined NPWT+insulin instillation treatment gave superior results by improving wound healing, decreasing inflammation at the wounds surface, and reducing IR in diabetic patients with infected DFUs.