Evidence based review of negative pressure wound therapy

Hierarchically Assembled Nanofiber Scaffolds with Dual Growth Factor Gradients Promote Skin Wound Healing Through Rapid Cell Recruitment

To address current challenges in effectively treating large skin defects caused by trauma in clinical medicine, the fabrication, and evaluation of a novel radially aligned nanofiber scaffold (RAS) with dual growth factor gradients is presented. These aligned nanofibers and the scaffold's spatial design provide many all-around "highways" for cell migration from the edge of the wound to the center area. Besides, the chemotaxis induced by two growth factor gradients further promotes cell migration. Incorporating epidermal growth factor (EGF) aids in the proliferation and differentiation of basal layer cells in the epidermis, augmenting the scaffold's ability to promote epidermal regeneration. Concurrently, the scaffold-bound vascular endothelial growth factor (VEGF) recruits vascular endothelial cells at the wound's center, resulting in angiogenesis and improving blood supply and nutrient delivery, which is critical for granulation tissue regeneration. The RAS+EGF+VEGF group demonstrates superior performance in wound immune regulation, wound closure, hair follicle regeneration, and ECM deposition and remodeling compared to other groups. This study highlights the promising potential of hierarchically assembled nanofiber scaffolds with dual growth factor gradients for wound repair and tissue regeneration applications.

Use of the modified meek technique for the coverage of extensive burn wounds

INTRODUCTION

Autologous split thickness skin grafting using meshing technique remains the preferred option for the management of deep dermal and full thickness burns. The limited donor site availability seen in patients with extensive burns, however, restricts use of the mesh grafting technique for skin expansion. Meek micrografting was developed to allow for greater expansion, and, therefore, more reliable treatment of extensive burns. This study aimed to present our outcomes using the Meek micrografting technique and identify risk factors for graft failure.

METHODS

A retrospective review of patients admitted to our large academic hospital who were treated with the Meek micrografting technique from 2013 to 2022 was conducted. Patient demographics, surgical characteristics and outcomes were reported. Regression analyses were performed to identify factors that influence graft take and reoperation rate.

RESULTS

A total of 73 patients with a mean age of 45.7 ± 19.9 years and mean burn size of 60.0 ± 17.8%TBSA, with 45.3 ± 14.9% TBSA being third degree burns, received Meek transplantation. The mean graft take after removal of the pre-folded polyamide gauze at the tenth post-operative day was 75.8 ± 14.7%. Pre-treatment with use of an allograft, longer waiting time between admission and Meek grafting and transplantation over a dermal matrix were identified as positive predictors for graft take, while age was established as a negative predictor.

CONCLUSION

By examining the outcomes of the Meek micrografting technique in extensive burn wounds we identified that preconditioning of the wound bed, through allograft or negative pressure wound therapy application, positively correlates with improved outcomes, including higher graft take. At the same time, older age was seen to negatively correlate with graft take. Overall, Meek transplantation displays a favorable safety profile with promising outcomes. Future prospective studies and clinical trials can optimize the procedure and help establish it as the golden standard for extensive and complex burns.

Primary Closure Versus Delayed Primary Closure of Class III and IV Surgical Wounds Following Emergency Laparotomy: A Prospective Comparative Study

Introduction Emergency surgery has a high risk of complications due to the detrimental effect of perioperative sepsis and the relative lack of preoperative optimization of patients. Despite advances in critical care for the management of sepsis, its prevention is dependent on various patient and surgeon factors. Surgical site infection continues to be a major determinant of morbidity and mortality following emergency abdominal surgery, especially in contaminated or dirty wounds. This study aims to compare two techniques of abdominal wall closure, primary closure with subcutaneous suction drains and delayed primary closure following negative pressure wound therapy, in terms of incidence of surgical site infection and morbidity. Materials and methods The study was a prospective comparative study including 50 patients with an acute surgical abdomen requiring laparotomy. The patients were randomized into two groups, Group A (n=25) who underwent primary closure, and Group B (n=25) who underwent delayed primary closure. In Group B patients, a vacuum-assisted closure device was applied in the subcutaneous space for five days prior to the closure of the skin. Outcomes were compared in terms of the incidence of superficial and deep surgical site infection, its association with diabetes mellitus, and the total duration of hospital stay. A chi-square test and an unpaired t-test were used for the test of significance. Results A total of 50 patients, comparable in age, were included in the study. The overall incidence of surgical site infection was significantly higher in patients of Group A as compared to Group B (p=0.0046). There was a positive correlation between diabetes mellitus and the occurrence of wound infection in both groups with the odds ratio being 2.67 and 2.38 respectively. The incidence of superficial wound infection was significantly higher in Group A when compared to Group B (52% versus 24%; p=0.04). Deep surgical site infection was higher in patients of Group A (20% versus 8%) but was not statistically significant (p=0.22). The average duration of hospital stay was 41.56 ± 6.96 and 37.86 ± 6.68 days for patients who developed complications from Groups A and B respectively, while it was nearly two and a half times lower in uncomplicated cases of Groups A and B (11.71± 1.70 days and 16.58± 1.06 days respectively). The one-tailed unpaired t-test showed a significant difference in means of hospital stay between patients with and without complications (T: 17.06, critical value: 1.677). Conclusion Delayed primary closure is an effective method of managing contaminated and dirty wounds following emergency laparotomy. Negative pressure wound therapy is one technique for preventing wound bed infection and accelerating wound healing in such cases. By combining the above in emergency surgeries, the incidence of surgical site infection and duration of hospital stay can be significantly reduced.

A Novel No Foil-to-Skin Contact Technique for Vacuum-assisted Wound Closure in Patients with Sensitive Skin

In some patients with chronic wounds, the surrounding skin is so injured due to various underlying conditions that negative pressure dressing cannot be applied or cannot function properly. Having faced this problem in our everyday practice, we developed a new skin-sparing technique for vacuum-assisted wound closure, which ensures that the peri-wound skin does not come into contact with the transparent adhesive films.

Methods

For 9 months (April-December 2022), we performed 32 vacuum wound dressings with the newly developed technique using the 3M ActiV.A.C. Therapy Unit and accessories, and Convatec's VARIHESIVE, avoiding skin contact with the adhesive films.

Results

Seven patients with 11 wounds who had sensitive skin or allergy to the conventionally used adhesive films were successfully treated with the new technique. The negative pressure wound dressings remained intact and functioned properly for up to 168 hours without compromising patients' daily activities and therapy.

Conclusion

The novel "no foil-to-skin contact" technique for vacuum-assisted wound closure can successfully be incorporated in the treatment of patients in whom conventional negative pressure dressings are otherwise not applicable.

Characteristics and Outcomes of Patients Undergoing Surgical Management of Hidradenitis Suppurativa: An ACS-NSQIP Data Analysis

Objective: Hidradenitis suppurativa (HS) is a painful inflammatory skin disease. Management is largely medical, with surgery reserved for severe refractory cases. In this study, we sought to conduct a retrospective analysis of a multi-institutional surgical database to investigate the surgical management of patients with HS and identify trends in the postoperative outcomes. Approach: The 2011-2019 American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was reviewed to identify patients who underwent surgery for management of HS. Postoperative outcomes were assessed, including surgical and medical complications, length of hospital stay, reoperation, readmission, and nonhome discharge. This article was reported according to the STROBE criteria. Results: We identified 1,030 patients, of which 62% were female and 50% were black. The most common comorbidity was obesity (61%). Surgery was mainly performed by general surgeons (62%) and plastic surgeons (31%). Complications were overall low, with readmission being the most common (7.1%, unplanned 6.0%), followed by reoperation (5.8%). The most common surgical complication was superficial incisional infection (5.1%) and most common medical complication was sepsis (3.8%). Obesity is seen to affect surgical complication rates, with patients with obesity having higher rates of dehiscence (obese: 3.1% and nonobese: 1.0%; p = 0.03) but lower rates of organ space infection (obese: 0.5% and nonobese: 2.0%; p = 0.03) and transfusion (obese: 2.5% and nonobese: 5.2%; p = 0.04). A focus on complications in patients undergoing flap reconstruction (n = 293; 23%), identified higher rates of surgical complications, with superficial incisional infection being the most common (flap reconstruction: 7.5% and incision and drainage, debridement, skin graft: 4.1%; p = 0.04). Innovation: The surgical management of HS is analyzed at the national level, with postoperative complications seen to depend on race and obesity-status. Conclusions: Surgical management for HS is associated with low postoperative complications, making surgery a viable treatment option for this debilitating disease.

Skin Inflammation with a Focus on Wound Healing

Significance: The skin is the crucial first-line barrier against foreign pathogens. Compromise of this barrier presents in the context of inflammatory skin conditions and in chronic wounds. Skin conditions arising from dysfunctional inflammatory pathways severely compromise the quality of life of patients and have a high economic impact on the U.S. health care system. The development of a thorough understanding of the mechanisms that can disrupt skin inflammation is imperative to successfully modulate this inflammation with therapies. Recent Advances: Many advances in the understanding of skin inflammation have occurred during the past decade, including the development of multiple new pharmaceuticals. Mechanical force application has been greatly advanced clinically. Bioscaffolds also promote healing, while reducing scarring. Critical Issues: Various skin inflammatory conditions provide a framework for analysis of our understanding of the phases of successful wound healing. The large burden of chronic wounds on our society continues to focus attention on the chronic inflammatory state induced in many of these skin conditions. Future Directions: Better preclinical models of disease states such as chronic wounds, coupled with enhanced diagnostic abilities of human skin, will allow a better understanding of the mechanism of action. This will lead to improved treatments with biologics and other modalities such as the strategic application of mechanical forces and scaffolds, which ultimately results in better outcomes for our patients.

Modulation of Lymphangiogenesis in Incisional Murine Diabetic Wound Healing Using Negative Pressure Wound Therapy

Objective: Despite the significant function of lymphatics in wound healing, and frequent clinical use of Negative Pressure Wound Therapy (NPWT), the effect of mechanical force application on lymphangiogenesis remains to be elucidated. We utilize a murine incisional wound healing model to assess the mechanisms of lymphangiogenesis following NPWT. Approach: Dorsal incisional skin wounds were created on diabetic mice (genetically obese leptin receptor-deficient mice [db/db]; n = 30) and covered with an occlusive dressing (Control, n = 15) or NPWT (-125 mmHg, continuous, 24 h for 7 days; NPWT, n = 15). The wounds were macroscopically assessed for 28 days. Tissue was harvested on day 10 for analysis. Qualitative functional analysis of lymphatic drainage was performed on day 28 using Evans Blue staining (n = 2). Results: NPWT increased lymphatic vessel density (40 ± 20 vs. 12 ± 6 podoplanin [PDPN]⁺ and 25 ± 9 vs. 14 ± 8 lymphatic vessel endothelial receptor 1 [LYVE-1]⁺) and vessel diameter (28 ± 9 vs. 12 ± 2 μm). Western blotting verified the upregulation of LYVE-1 with NPWT. Leukocyte presence was higher with NPWT (22% ± 3.7% vs. 9.1% ± 4.1% lymphocyte common antigen [CD45]⁺) and the leukocytes were predominately B cells clustered within vessels (8.8% ± 2.5% vs. 18% ± 3.6% B-lymphocyte antigen CD20 [CD20]⁺). Macrophage presence was lower in the NPWT group. Lymphatic drainage was increased in the NPWT group, which exhibited greater Evans Blue positivity. Innovation: The lymphangiogenic effects take place independent of macrophage infiltration, appearing to correlate with B cell presence. Conclusion: NPWT promotes lymphangiogenesis in incisional wounds, significantly increasing the lymph vessel density and diameter. This study highlights the potential of NPWT to stimulate lymphatic drainage and wound healing of surgical incisions.

Outcomes Following Use of Negative-Pressure Wound Therapy Over Autologous Meshed and Non-Meshed Skin Grafts

Negative-pressure wound therapy (NPWT) over split thickness skin grafts can control exudate, decrease infection rates, and improve revascularization. However, no study specifically addresses differences in outcomes between meshed/perforated and non-meshed autologous skin grafts dressed with NPWT. Through retrospective chart review, patients undergoing autologous split thickness skin grafting with a NPWT dressing for any burn injury over a 10-month period were identified. Data on etiology, graft take, meshed/perforated or non-meshed graft, graft size, and seroma/hematoma incidence were collected. Our study included 123 patients who had STSG with NPWT and consisted of 57% males, 57% Caucasian, and an average age of 41. Burn injury etiologies consisted of scald (55%), chemical (25%), flame (15%), and contact (5%). Average 2nd degree TBSA in our cohort was 2.34%, 3rd degree TBSA 4.50%, and total TBSA 5.35%. 66.7% of patients received non-meshed grafts, and these patients had an average graft area of 76.5 cm2. 33.3% of patients received meshed grafts, with an average graft area of 163.5 cm2. Non-meshed burn grafts were significantly smaller than meshed grafts (P = .04). There was 100% graft take and 0% seroma/hematoma formation in all patients. Data was analyzed using an unpaired student's T test and ANOVA testing. There were no statistically significant differences in patient demographics, or burn etiology. There exist many options for dressings after repair of burn injuries, each with its own unique advantages. There were, however, no differences in graft take or incidence of seroma/hematoma formation using a NPWT dressing over autologous meshed grafts vs non-meshed grafts. Our data shows that NPWT use as a bolster dressing is safe and efficacious overlying meshed skin grafts and non-meshed grafts.

Negative-Pressure Wound Therapy: What We Know and What We Need to Know

Negative-pressure wound therapy (NPWT) promotes wound healing by applying negative pressure to the wound surface. A quarter of a century after its introduction, NPWT has been used in various clinical conditions, although molecular biological evidence is insufficient due to delay in basic research. Here, we have summarized the history of NPWT, its mechanism of action, what is currently known about it, and what is expected to be known in the future. Particularly, attention has shifted from the four main mechanisms of NPWT to the accompanying secondary effects, such as effects on various cells, bacteria, and surgical wounds. This chapter will help the reader to understand the current status and shortcomings of NPWT-related research, which could aid in the development of basic research and, eventually, clinical use with stronger scientific evidence.

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

BACKGROUND

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.

MATERIALS AND METHODS

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 24 h 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.

RESULTS

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 9 h evaluated by the scratch assay was significantly smaller in the NPc and NPi groups than in the AP group.

CONCLUSION

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.

Autologous whole blood clot and negative-pressure wound therapy in South Africa: A comparison of the cost and social considerations

BACKGROUND

Advanced wound treatment modalities enhance healing of hard-to-heal wounds, decrease the risk of amputations, and improve the quality of life of patients. Modalities have different rates of efficacy and incur different social and financial costs to the individual and the healthcare system. Two such modalities, the autologous whole blood clot (WBC) and negative-pressure wound therapy (NPWT), were compared in the South African (SA) context. The comparison was conducted on hard-to-heal wounds, with a specific focus on diabetic foot ulcers (DFUs).

OBJECTIVES

To compare the social considerations and financial costs of using autologous WBC v. NPWT in the treatment of DFUs in SA.

METHODS

Data were obtained based on current supply costs from SA suppliers for the two modalities, the standard of care for both modalities, the number of applications required for each, and social considerations provided by SA wound management clinicians. Wound healing rates were obtained from the published literature. This information was used to calculate costs of two scenarios (scenario 1: low exudate v. scenario 2: high exudate), which were compared over two treatment durations (4 and 12 weeks) for each treatment modality. Calculations included weekly cost of supplies, total cost saved by a patient with a DFU managed with either of the wound therapies, and the difference in total cost saved between the two modalities. Key social considerations were assessed qualitatively from discussions with SA clinicians experienced in both autologous WBC and NPWT, and from published research.

RESULTS

The cost of supplies per week was ZAR3 250 for autologous WBC and ZAR4 804 for NPWT in scenario 1, and ZAR3 332 and ZAR6 612 in scenario 2. With healing rates over 4 weeks' treatment duration of 19% for autologous WBC and 10% for NPWT, autologous WBC saved ZAR17 719.93, or 9% more than using NPWT, in scenario 1 and ZAR18 381.47, or 10% more, in scenario 2. At 12 weeks' treatment duration, healing rates for autologous WBC and NPWT were 75% and 43%, respectively. In scenario 1, results indicated a 43% cost difference between the two modalities. Autologous WBC had a total cost saving of ZAR61 874.40 compared with NPWT over a period of 12 weeks. In scenario 2, results indicated a 46% cost difference between the two modalities. Autologous WBC had a total cost saving of ZAR70 454.68 compared with NPWT over a period of 12 weeks. One of the identified social considerations is that NPWT needs a reliable supply of electricity to recharge the pump, while autologous WBC does not.

CONCLUSION

Both modalities are safe and effective in treating hard-to-heal wounds of the lower extremities. Autologous WBC consistently demonstrated better outcomes than NPWT in terms of both healing rate and cost-effectiveness, as well as having some advantages in terms of social considerations in SA.

The Association between Neoadjuvant Radio-Chemotherapy and Prolonged Healing of Anastomotic Leakage after Esophageal Resection Treated with EndoVAC Therapy

(1) Background: Endoscopic vacuum therapy (EVT) has become the mainstay in the treatment of early anastomotic leakage (AL) after esophageal resection. The effect of nRCT on the efficacy of EVT is currently unknown. (2) Methods: Data of 427 consecutive patients undergoing minimally invasive esophagectomy between 2013 and 2022 were analyzed. A total of 26 patients received EVT for AL after esophagectomy between 2010 and 2021. We compared a cohort of 13 patients after treatment with EVT for anastomotic leakage after neoadjuvant radiochemotherapy (nRCT) with a control group of 13 patients after neoadjuvant chemotherapy (nCT) using inverse propensity score weighting to adjust for baseline characteristics between the groups. EVT therapy was assessed regarding patient survival, treatment failure as defined by a change in treatment to stent/operation, duration of treatment, and secondary complications. Statistical analysis was performed using linear regression analysis. (3) Results: Time to EVT after initial tumor resection did not vary between the groups. The duration of EVT was longer in patients after nRCT (14.69 days vs. 20.85 days, p = 0.002) with significantly more interventions (4.38 vs. 6.85, p = 0.001). The success rate of EVT did not differ between the two groups (nCT n = 8 (61.54%) vs. nCT n = 5 (38.46%), p = 0.628). The rate of operative revision did not vary between the groups. Importantly, no mortality was reported within 30 days and 90 days in both groups. (4) Conclusions: EVT is a valuable tool for the management of AL after esophageal resection in patients after nRCT. While the success rates were comparable, EVT was associated with a significantly longer treatment duration. Anastomotic leakages after nRCT often require prolonged and multimodal treatment strategies while innovative strategies such as prophylactic endoVAC placement or use of a VAC-Stent may be considered.

Application of Negative Pressure Therapy on Skin Grafts after Soft-Tissue Reconstruction: A Prospective Observational Study

A split-thickness skin graft (STSG) is one of the main tools used in the reconstruction of skin defects. Negative-pressure wound therapy (NPWT) has been widely used as adjunct therapy for wound healing for decades. Few studies have conducted the outcomes of NPWT use as a postoperative dressing for STSGs. This study aimed to compare the outcomes of the application of NPWT versus conventional dressing on STSGs after soft-tissue reconstruction. A prospective observational study was performed at the King Abdullah Medical City. A total of 18 patients with STSGs for acute or chronic skin defects were recruited. Patients from the two groups—10 patients in the NPWT group and 8 in the No-NPWT group—were postoperatively evaluated for three weeks. Assessment included the STSG take rate, wound healing, pain, infection, hematoma formation, and the need to re-graft the same recipient area. Our data demonstrated a higher mean skin graft take rate in the second and third weeks of the No-NPWT group compared to the NPWT group, but it was not statistically significant (p > 0.05). No significant differences between the two groups in terms of wound healing, pain, infection, hematoma formation, and the need to re-graft (p > 0.05) were found. Our study showed that the conventional dressing of STSGs is not inferior to NPWT. In addition, conventional dressing was shown to be easier to use and less expensive to apply, as well as having a higher skin graft take rate and lower infection rate.

Postoperative Fluid Collections in Total Joint Arthroplasty: A Narrative Review

A post-operative fluid collection (POFC) represents a common finding in both primary and revision total joint arthroplasty (TJA). Fortunately, most resolve on their own, but in instances where they become symptomatic, prompt identification and management are paramount, especially when they occur adjacent to a joint arthroplasty because of the increased the risk of developing a periprosthetic joint infection. A strong clinical suspicion with appropriate clinical exam is required along with select imaging modalities to arrive at a diagnosis. Meticulous surgical technique is crucial to prevent POFC, but new emerging treatments continue to evolve. This article presents an updated overview of incidence, pathophysiology, diagnosis, and management of POFC in the setting of TJA. We review the role of select imaging modalities as well as summarize current literature regarding new treatments such as sclerotherapy agents, acellular dermal matrices, and negative pressure wound therapy. Future studies are necessary to explore the interplay of inflammatory mediators in POFC formation and to define their role in fluid collection resolution.

Wound contraction under negative pressure therapy measured with digital image correlation and finite-element analysis in tissue phantoms and wound models

The purpose of this study is to demonstrate the capabilities of finite-element (FE) models to predict contraction of wounds managed with negative pressure wound therapy (NPWT). The features of wounds and surrounding tissues were analysed to gain insights into the mechanical effects of NPWT on them. 3D digital image correlation (DIC) measurement of soft tissue phantoms was used to investigate the effect of wound thickness, size, and shape, which were further compared with results of FE simulations. It was noticed that with an increased NP level the difference between DIC and FE in wound contraction became more pronounced, particularly for the thick wounds. In addition, the locations of the wounds were evaluated to predict their contraction characteristics, based on surrounding tissue structures, in 3D using the developed FE models. It was demonstrated that features and location of wounds influenced their deformations differently for the same pressure levels. Overall, this study, involving a combined experimental and computational approach, allowed the important insights into mechanical effects of NPWT.

Abdominal Soft Tissue Infection Caused by Mycobacterium wolinskyi After Cosmetic Surgery: A Case Report

BACKGROUND

Mycobacterium wolinskyi is a rare, fast-growing, painful bacterium causing soft tissue infections. Sparse case reports focus on long-term intravenous antibiotic therapy and surgical interventions. We searched the literature and found almost no discussion about treatment from a nursing and wound care perspective.

CASE

Ms P, a 30-year-old Arabic female patient, underwent cosmetic surgery in Iraq including liposuction, abdominoplasty, and herniorrhaphy. One month postoperatively, she presented with an infection identified as M. wolinskyi resulting in multiple hospital admissions. Ms P received treatment with long-term antibiotic therapy and underwent multiple surgical debridements with extensive wound care management.

CONCLUSION

Mycobacterium wolinskyi is an exceedingly rare bacterium not typically seen in the clinical setting and requires prolonged and aggressive treatment. It is painful and fast-growing, as evidenced by multiple abscess formations and tissue necrosis in this case. Daily assessments and wound management using a collaborative approach were important to promote optimal healing.

Pre-Clinical Assessment of Single-Use Negative Pressure Wound Therapy During In Vivo Porcine Wound Healing

Objective: Traditional negative pressure wound therapy (tNPWT) systems can be large and cumbersome, limiting patient mobility and adversely affecting quality of life. PICO™, a no canister single-use system, offers a lightweight, portable alternative to tNPWT, with improved clinical performance. The aim of this study was to determine the potential mechanism(s) of action of single-use NPWT (sNPWT) versus tNPWT. Approach: sNPWT and tNPWT were applied to an in vivo porcine excisional wound model, following product use guidelines. Macroscopic, histological, and biochemical analyses were performed at defined healing time points to assess multiple aspects of the healing response. Results: Wounds treated with single-use negative pressure displayed greater wound closure and increased reepithelialization versus those treated with traditional negative pressure. The resulting granulation tissue was more advanced with fewer neutrophils, reduced inflammatory markers, more mature collagen, and no wound filler-associated foreign body reactions. Of note, single-use negative pressure therapy failed to induce wound edge epithelial hyperproliferation, while traditional negative pressure therapy compromised periwound skin, which remained inflamed with high transepidermal water loss; features not observed following single-use treatment. Innovation: Single-use negative pressure was identified to improve multiple aspects of healing versus traditional negative pressure treatment. Conclusion: This study provides important new insight into the differing mode of action of single-use versus traditional negative pressure and may go some way to explaining the improved clinical outcomes observed with single-use negative pressure therapy.

Endoscopic vacuum therapy for anastomotic leak in esophagectomy and total gastrectomy: a systematic review and meta-analysis

The curative treatment for esophageal and gastric cancer is primarily surgical resection. One of the main complications related to esophagogastric surgery is the anastomotic leak. This complication is associated with a prolonged length of stay, reduced quality of life, high treatment costs, and an increased mortality rate. The placement of endoluminal stents is the most frequent endoscopic therapy in these cases. However, since its introduction, endoscopic vacuum therapy has been shown to be a promising alternative in the management of this complication. This study primarily aims to evaluate the efficacy and safety of endoscopic vacuum therapy for the treatment of anastomotic leak in esophagectomy and total gastrectomy. A systematic review and meta-analysis was performed. Studies that evaluated the use of endoscopic vacuum therapy for anastomotic leak in esophagectomy and total gastrectomy were included. Twenty-three articles were included. A total of 559 patients were evaluated. Endoscopic vacuum therapy showed a fistulous orifice closure rate of 81.6% (rate: 0.816; 95% CI: 0.777-0.864) and, when compared to the stent, there is a 16% difference in favor of endoscopic vacuum therapy (risk difference [RD]: 0.16; 95% CI: 0.05-0.27). The risk for mortality in the endoscopic vacuum therapy was 10% lower than in endoluminal stent therapy (RD: -0.10; 95% CI: -0.18 to -0.02). Endoscopic vacuum therapy might have a higher rate of fistulous orifice closure and a lower rate of mortality, compared to intraluminal stenting.

Mechanotransduction in Wound Healing: From the Cellular and Molecular Level to the Clinic

GENERAL PURPOSE

To review the various mechanical forces that affect fibroblasts, keratinocytes, endothelial cells, and adipocytes at the cellular and molecular level as well as scar-reducing mechanical devices currently in clinical use.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will:1. Compare and contrast the responses of various types of cells to mechanical forces.2. Identify the mechanical devices and techniques that can help restore skin integrity.

Negative-pressure Wound Therapy for Sacral Pressure Ulcer in Gorham-Stout Disease

Gorham-Stout disease (GSD) is a rare musculoskeletal disorder characterized by progressive bone resorption and overgrowth of lymphatic vessels. The mechanism of GSD is still largely unknown. Negative-pressure wound therapy (NPWT) is known to accelerate wound healing and is used worldwide. Herein, we report a successful treatment of a patient with GSD having a sacral pressure ulcer, using NPWT. An 18-year-old female GSD patient was referred to our department for treating a sacral wound. The wound was disinfected by pocket incision, cleansing, and administration of antibiotics; however, the lesion remain unhealed. Histopathology of the debrided sacral wound revealed fibrous granulation tissue, with no sign of lymphatic anomalies. NPWT was started with −75 mm Hg of pressure, and neither lymphorrhea nor growth of lymphangioma was noted. Negative pressure was gradually increased to −125 mm Hg. The ulcer size decreased to 2 × 2 cm², which healed 3 months after hospital discharge, with no recurrence for 8 months. For progressive diseases such as GSD, NPWT may cause the regrowth of lymphangioma or other neoplasms due to an increase in vessel endothelial growth factor. NPWT appears to be one of the safest and most effective wound therapies even for this rare and difficult disease, provided the use of the following treatment protocol: Pathohistological assessment before application of NPWT, and negative pressure initially set at a low level; then, gradually increased, with careful observation to avoid lymphorrhea. When changing the foam dressing, careful checking is important to determine whether the wound is necrotic, or if there is tumor-like tissue accumulation rather than healthy granulation.

Cellular benefits of single-use negative pressure wound therapy demonstrated in a novel ex vivo human skin wound model

Negative pressure wound therapy is a widely used treatment for chronic, nonhealing wounds. Surprisingly, few studies have systematically evaluated the cellular and molecular effects of negative pressure treatment on human skin. In addition, no study to date has directly compared recently available single-use negative pressure modalities to traditional negative pressure devices in a controlled setting. Here we developed a novel large-scale ex vivo human skin culture system to effectively evaluate the efficacy of two different negative pressure wound therapy modalities. Single-use and traditional negative pressure devices were applied to human ex vivo wounded skin sheets cultured over a period of 48 hours. Cellular tissue response to therapy was evaluated via a combination of histological analysis and transcriptional profiling, in samples collected from the wound edge, skin adjacent to the wound, and an extended skin region. Single-use negative pressure wound therapy caused less damage to wound edge tissue than traditional application, demonstrated by improved skin barrier, reduced dermal-epidermal junction disruption and a dampened damage response. Transcriptional profiling confirmed significantly less activation of multiple pro-inflammatory markers in wound edge skin treated with single-use vs traditional negative pressure therapy. These findings may help to explain the greater efficacy of sNPWT in the clinic, while offering a noninvasive system to develop improved NPWT-based therapies.

Role of Negative Pressure Wound Therapy When Performing Elective Open Colectomy

Background: The impact of negative pressure wound therapy (NPWT) as an adjunct to colorectal surgery is largely unknown. The purpose of this study was to determine whether NPWT impacts wound complications during elective open colectomy. Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) and colectomy targeted procedure databases were queried from 2012-2018 for patients undergoing non-emergent planned open colectomies. Groups were propensity score matched for anastomosis type (ileo-colic, colo-colic, colo-rectal), age, body mass index (BMI), diabetes, smoking, steroid use, wound classification, American Society of Anesthesiologists (ASA) class, operative time, and wound layers closed. Wound complications were defined as superficial surgical site infection (SSI), deep incisional SSI, and dehiscence. Results: A total of 15,770 patients were identified; 92 underwent simultaneous NPWT (0.58%). Non-NPWT patients were matched at a 5:1 ratio, producing 460 comparisons. There was no difference in wound complications (8.26% non-NPWT vs. 6.52% NPWT; p = 0.574). In addition, there were no differences in wound complications when only including patients who had NPWT placed over closed skin (9.11% non-NPWT vs. 7.25% NPWT; p = 0.789). On multivariable analysis, NPWT was not associated with wound complications (odds ratio [OR] 0.79; 95% confidence interval [CI], 0.37-1.69). Conclusions: Negative pressure wound therapy does not reduce wound complications in open elective colectomies. Large randomized studies and more granular data are needed to ascertain if there is any benefit in select patient populations.

Role of Endoscopic Vacuum Therapy as a Treatment for Anastomosis Leak after Esophageal Cancer Surgery

Esophageal anastomotic leak is the most common and serious complication following esophagectomy. However, the standard treatment for anastomotic leaks remains unclear. Recently, endoscopic vacuum therapy has become an important non-surgical alternative treatment method for patients with esophageal anastomotic leak. This treatment involves the endoscopic placement of a sponge connected to a nasogastric tube into the defect cavity or lumen. Subsequently, continuous negative pressure is delivered to the cavity through the tube. Several studies have reported a treatment success rate of 80% to 100%. In this study, we review the mechanism of action, the method of performing the procedure, its safety and efficacy, and prognostic factors for failure of endoscopic vacuum therapy in the management of patients with anastomotic leak, and on this basis attempted to confirm the possibility of establishing a standardized treatment protocol using endoscopic vacuum therapy.

Treatment of hard-to-heal leg ulcers with hyaluronic acid, sodium alginate and negative pressure wound therapy

OBJECTIVE

Hard-to-heal lower extremity ulcer is a common healthcare problem and can lead to a poor quality of life (QoL). Despite the advances in wound care, conventional therapies, such as necrotic tissue debridement, cleansing, treatment of infection and local treatment with dressing application are still considered the standard of care in patients with hard-to-heal leg ulcers. However, managing hard-to-heal ulcers that do not respond well to these methods has led to new treatment strategies. In this study, the effects of hyaluronic acid (HA) and sodium alginate (SA), combined with negative pressure wound therapy (NPWT), in patients with hard-to-heal leg ulcers are evaluated.

METHOD

Patients with hard-to-heal lower extremity ulcers were treated with HA-SA combined with NPWT (HA-SA-NWPT, n=11), or conventional therapy (n=14), between June 2014 and September 2015. Demographics, comorbidities, time to complete healing and change in wound area were recorded and compared.

RESULTS

A total of 25 patients took part. Complete healing was achieved in 63.6% (n=7) of the patients in the HA-SA with NPWT group, compared with 14.3% (n=2) of the patients in the conventional therapy group (p=0.017). The mean decrease in wound size was significantly higher in the HA-SA-NPWT group than in the conventional therapy group (73.8% versus 34.8%, respectively, p=0.029). Despite a shorter healing period in the HA-SA-NPWT group than in the conventional group, no statistically significant difference was found between groups for time to complete healing (37 days versus 55 days, respectively).

CONCLUSION

These results demonstrate that the combination of HA-SA-NPWT is a promising treatment for decreasing the healing time and increasing the success rate by their synergistic effect on wound healing in hard-to-heal lower extremity ulcers. However, further studies with a larger number of patients are needed to confirm the results.

Spontaneous closure of an extensive postdebridement perineal wound in a newly diagnosed diabetic patient presenting with necrotizing fasciitis

Diabetes mellitus may present for the first time with necrotizing fasciitis. Early treatment of septic shock and immediate surgical debridement reduces mortality. A diverting loop colostomy prevents soiling of extensive postdebridement wound. Local wound care together with good glycemic and infection control leads to spontaneous wound closure.

Tapering pressure of wall vacuum-assisted closure for the treatment of patients with pancreatic fistula in traumatic pancreatic injury: Report of two cases

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Postoperative pancreatic fistula is a nightmare for digestive surgeons.

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Requires complex treatment and a long duration of hospitalization of patients with a large cost burden.

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VAC using wall suction with NPWT principle can be used to treat patients with complex wounds.

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A simple and easy procedure with good outcomes.

Introduction

Traumatic injury to the pancreas is rare and difficult to diagnose, requiring immediate operative management. It also has high mortality and morbidity rates. Postoperative pancreatic fistula is one of the complications that is considered a nightmare for digestive surgeons. The prevalence of POPF is estimated at 13%–41%, with 28% of mortality rate and the most common cause of death is retroperitoneal sepsis and hemorrhage. It requires complex treatment and a long duration of hospitalization of patients with a large cost burden.

Presentation of case

Here we report 2 cases of POPF after pancreatic injury in abdominal trauma. The patients underwent emergency laparotomy. In the hospital ward, the patients developed wound dehiscence and a clear viscous pancreatic juice came out from the wound with high output. The installation of wall VAC using wall suction with pressure adjustments according to the number of products per day was performed. The patients showed good outcomes, the pancreatic juice output decreased and diminished, and the wound also narrowed and closed.

Discussion

VAC using wall suction is a device that applies the technique of NPWT and an emerging procedure used to treat patients with complex wounds. NPWT can reduce pooling of fluid, while reducing shear stress and tissue hypoxia at the wound edges, and stimulating the release of vascular endothelial growth factor in wound milieu.

Conclusions

Tapering pressure of VAC using wall suction for treatment of pancreatic fistula in post laparotomy pancreatic injury patients is a simple and easy procedure with good outcomes.

Therapeutic advances in wound healing

Wound healing is a complex physiological process that occurs in the human body involving the sequential activation of multiple cell types and signaling pathways in a coordinated manner. Chronic wounds and burns clearly decrease quality of life of the patients since they are associated with an increase in physical pain and socio-economical complications. Furthermore, incidence and prevalence of chronic wounds (unlike burns) have been increasing mainly due to population aging resulting in increased costs for national health systems. Thus, the development of new and more cost-effective technologies/therapies is not only of huge interest but also necessary to improve the long-term sustainability of national health systems. This review covers the current knowledge on recent technologies/therapies for skin regeneration, such as: wound dressings; skin substitutes; exogenous growth factor based therapy and systemic therapy; external tissue expanders; negative pressure; oxygen; shock wave, and photobiomodulation wound therapies. Associated benefits and risks as well as the clinical use and availability are all addressed for each therapy. Moreover, future trends in wound care including novel formulations using metallic nanoparticles and topical insulin are herein presented. These novel formulations have shown to be promising therapeutic options in the near future that may change the wound care paradigm.

Factors affecting postmusculoskeletal tumour surgery wound problem treatment with negative pressure wound therapy

The aim of the study is to investigate the risk factors identified in literature that have been associated with prolonged Negative Pressure Wound Therapy (NPWT). Our study included patients who developed local wound problems after bone or soft tissue sarcoma surgery with negative margin at our clinic between 2012 and 2018 and treated with NPWT. All patients were followed up of at least 6 months. Sex, albumin level, skin infiltration, type of wound problem, postoperative intensive care unit (ICU) requirement, and intraoperative blood loss were found to be influential factors on NPWT > 10 sessions. We conclude that treatment may be prolonged and the necessary precautions need to be taken in patients with an impaired preoperative nutritional condition, with intraoperative high amount of blood loss, and with long postoperative stays in the ICU as well as if the underlying cause for wound problem is an infection.

A Prospective, Multicenter, Single-Arm Clinical Trial for Treatment of Complex Diabetic Foot Ulcers with Deep Exposure Using Acellular Dermal Matrix

OBJECTIVE

This prospective, multicenter study evaluated the efficacy and safety of an acellular dermal matrix allograft, DermACELL (D-ADM; LifeNet Health, Virginia Beach, Virginia), in the treatment of large, complex diabetic foot ulcers (DFUs) that probed to tendon or bone.

METHODS

Inclusion criteria were Wagner grade 3 or 4 DFUs between 4 weeks and 1 year in duration. All participants received one application of D-ADM at baseline and could receive one additional application if wound healing arrested. Ulcers were assessed weekly for 16 weeks using a laser measuring device.

RESULTS

Sixty-one participants were enrolled, with an average wound area of 29.0 cm²; 59 of these ulcers showed exposed bone. The entire per-protocol population (n = 47) achieved 100% granulation. The mean time to 100% granulation was 4.0 weeks with an average of 1.2 applications of D-ADM. Mean percent wound area reduction was 80.3% at 16 weeks. Those DFUs 15 cm² or smaller were substantially more likely to close than DFUs larger than 29 cm² (P = .0008) over a 16-week duration. No complications were associated with the use of the studied matrix.

CONCLUSIONS

The D-ADM demonstrated the ability to rapidly reduce the size of large, complex DFUs with exposed bone. Some wounds did not completely heal by 16 weeks; however, the significant reduction in size suggests that these large, complex wounds may heal if given more time.

Role of endoscopic vacuum therapy in the management of gastrointestinal transmural defects

A gastrointestinal (GI) transmural defect is defined as total rupture of the GI wall, and these defects can be divided into three categories: perforations, leaks, and fistulas. Surgical management of these defects is usually challenging and may be associated with high morbidity and mortality rates. Recently, several novel endoscopic techniques have been developed, and endoscopy has become a first-line approach for therapy of these conditions. The use of endoscopic vacuum therapy (EVT) is increasing with favorable results. This technique involves endoscopic placement of a sponge connected to a nasogastric tube into the defect cavity or lumen. This promotes healing via five mechanisms, including macrodeformation, microdeformation, changes in perfusion, exudate control, and bacterial clearance, which is similar to the mechanisms in which skin wounds are treated with commonly employed wound vacuums. EVT can be used in the upper GI tract, small bowel, biliopancreatic regions, and lower GI tract, with variable success rates and a satisfactory safety profile. In this article, we review and discuss the mechanism of action, materials, techniques, efficacy, and safety of EVT in the management of patients with GI transmural defects.

Negative pressure wound therapy use in diabetic foot syndrome-from mechanisms of action to clinical practice

BACKGROUND

Diabetes and its complications constitute a rising medical challenge. Special attention should be given to diabetic foot syndrome (DFS) due to its high rate of associated amputation and mortality. Negative pressure wound therapy (NPWT) is a frequently used supportive modality in a diabetic foot with ulcerations (DFUs).

DESIGN

Here, we reviewed the current knowledge concerning the tissue and molecular mechanisms of NPWT action with an emphasis on diabetes research followed by a summary of clinical DFU studies and practice guidelines.

RESULTS

Negative pressure wound therapy action results in two types of tissue deformations-macrodeformation, such as wound contraction, and microdeformation occurring at microscopic level. Both of them stimulate a wound healing cascade including tissue granulation promotion, vessel proliferation, neoangiogenesis, epithelialization and excess extracellular fluid removal. On the molecular level, NPWT results in an alteration towards more pro-angiogenic and anti-inflammatory conditions. It increases expression of several key growth factors, including vascular endothelial growth factor and fibroblast growth factor 2, while expression of inflammatory cytokinesis reduced. The NPWT application also alters the presence and function of matrix metalloproteinases. Clinical studies in DFU patients showed a superiority of NPWT over standard therapy in terms of efficacy outcomes, primarily wound healing and amputation rate, without a rise in adverse events. International guidelines point to NPWT as an important adjuvant therapy in DFU whose use is expected to increase.

CONCLUSIONS

This current knowledge improves our understanding of NPWT action and its tailoring for application in diabetic patients. It may inform the development of new treatments for DFU.