EWMA Document: Negative Pressure Wound Therapy

NPWT resource use compared with standard moist wound care in diabetic foot wounds: DiaFu randomized clinical trial results

Background

Diabetic foot ulcers not only have a negative impact on patient mortality, morbidity and quality of life, but also require high resource utilization to achieve complete wound healing. The aim of this evaluation was to compare resource utilization of negative pressure wound therapy (NPWT) and standard moist wound care (SMWC) for diabetic foot wounds after amputation, surgical debridement or wound cleansing.

Methods

The multicenter clinical DiaFu study enrolled 368 adults with diabetic foot ulcers between December 23, 2011 and October 21, 2014. Patients were randomly assigned to NPWT and SMWC. Evaluation of direct resource use comprised inpatient and outpatient treatment time, and personnel and material for wound treatment within 16 weeks. This resource use analysis was primarily based on the per protocol population (NPWT 44; SMWC 110).

Results

Treatment duration was 16 days shorter with NPWT (mean (SD) 82.8 (31.6), SMWC 98.8 (24.6); U test, p = 0.001) with 14.9 days shorter outpatient treatment (mean (SD) NPWT 68.3 (31.1), SMWC 83.2 (29.7)). The number of dressing changes per study participant was lower with NPWT (mean (SD) 35.1 (18.6), SMWC (42.9 (21.4); U test, p = 0.067). Time per dressing change was significantly lower with SMWC (mean (SD) 19.7 (12.8), NPWT (16.5 (8.2) minutes; U test, p < < 0.0001). Time for surgical debridements per study participant was 23.3 minutes shorter with NPWT (mean (SD) 20.5 (20.5), SMWC (43.8 (46.7); U test, p = 0.395).

Conclusions

Resource use was lower for NPWT, which may be an efficient treatment alternative to SMWC for diabetic foot wounds, to be demonstrated in subsequent cost analyses.

Trial registration

clinicaltrials.govNCT01480362 on November 28, 2011

Supplementary Information

The online version contains supplementary material available at 10.1186/s13047-022-00569-w.

Device for Negative Pressure Wound Therapy in Low-Resource Regions: Open-Source Description and Bench Test Evaluation

Background: Negative (vacuum) pressure therapy promotes wound healing. However, commercially available devices are unaffordable to most potential users in low- and middle-income countries (LMICs), limiting access to many patients who could benefit from this treatment. This study aimed to design and test a cheap and easy-to-build negative pressure device and provide its detailed open-source description, thereby enabling free replication. Methods: the negative pressure device was built using off-the-shelf materials available via e-commerce and was based on a small pump, a pressure transducer, and the simplest Arduino controller with a digital display (total retail cost ≤ 75 US$). The device allows the user to set any therapeutic range of intermittent negative pressure and has two independent safety mechanisms. The performance of the low-cost device was carefully tested on the bench using a phantom wound, producing a realistic exudate flow rate. Results: the device generates the pressure patterns set by the user (25–175 mmHg of vacuum pressure, 0–60 min periods) and can drain exudate flows within the clinical range (up to 1 L/h). Conclusions: a novel, low-cost, easy-to-build negative pressure device for wound healing displays excellent technical performance. The open-source hardware description provided here, which allows for free replication and use in LMICs, will facilitate the application and wider utilization of this therapy to patients.

Treatment of diabetic foot ulcers: review of the literature with regard to the TIME clinical decision support tool

OBJECTIVE

The aim of this clinically orientated paper is to offer an overview of diabetic foot ulcer (DFU) dressings generally, and more specifically, their use in the treatment of DFUs.

METHOD

The TIME clinical decision support tool (CDST) has been used as a clinical tool that can help clinicians bring together the different aspects of dressings for DFU treatment into a holistic approach to patient care.

RESULTS

DFUs are often difficult to heal, are painful and impact negatively on the individual's quality of life. Most DFU dressings are designed to support the healing of hard-to-heal wounds and represent one part of the management of DFUs. Apart from providing a moist environment, absorbing increased exudate, enhancing granulation and assisting in autolysis, the dressings need to be cost-effective. Wound dressing selection is based on clinical knowledge that ensures the dressing is most appropriate for the individual and the wound, taking into account the comorbidities that the individual may have.

CONCLUSION

This paper has highlighted how the use of the TIME CDST model can enhance clinical care and is a further tool clinicians should consider when developing and executing DFU treatment plans. Future research needs to focus on large multicentre studies using robust methodologies, given the current gaps in the evidence, to determine the effectiveness of dressing products for DFUs.

The local physiological effects of a single-use topical negative pressure device in healthy volunteers: the PICO-1 study

OBJECTIVE

This study aimed to investigate the effects of a single-use negative pressure wound therapy (sNPWT) device on tissue perfusion, oxygenation and pressure in the intact skin of healthy volunteers.

METHOD

Healthy volunteers wore a PICO sNPWT device (Smith+Nephew, UK) on their right medial calf for one week. Perfusion, tissue oxygenation and tissue pressure were recorded in superficial and deep tissues over a period of seven days. At the baseline visit, measurements were recorded before and after dressing application without activation. Macrovascular flow and transduced needle pressure measures were recorded at 0 minutes, 30 minutes and 60 minutes after device activation. Superficial tissue perfusion and both oxygenation measures were recorded continuously over the hour following activation. All outcome measures were repeated at 24 hours and again after seven days, both with the dressing and following dressing removal.

RESULTS

The device was associated with a measurable increase in perfusion of the limb in 12 healthy volunteers. Superficial tissue oxygenation adjacent to the dressing was reduced during wear, while deeper tissue demonstrated an increase in oxygenation levels. Superficial skin perfusion was observed to differ between skin overlying muscle and that overlying bone. Pressure in tissue underneath the dressing pad was increased throughout dressing wear and returned to baseline levels on dressing removal.

CONCLUSION

sNPWT produced measurable changes in local physiology in healthy volunteers with intact skin, despite the absence of a wound. Effects may differ according to anatomical site and the composition of underlying tissues. Other factors that promote healing were not explored in this study.

DECLARATION OF INTEREST

This study was funded by Smith+Nephew investigator-initiated grant IIS 684. The funder had no input into study design, conduct, analysis, manuscript preparation or dissemination. The authors have no conflicts of interest to declare.

Antibiotic-loaded Bone Cement Combined with Vacuum-assisted Closure Facilitating Wound Healing in Wagner 3-4 Diabetic Foot Ulcers

This study explored the clinical effectiveness of antibiotic-loaded bone cement (ALBC) combined with vacuum-assisted closure (VAC) on the treatment of Wagner 3-4 diabetic foot ulcers (DFUs). This is a retrospective study, including 32 patients with Wagner 3-4 DFUs who had undergone treatment between August 2019 and June 2021. Patient age, sex, Hemoglobin A1c (HbA1c), body mass index (BMI), ankle brachial index (ABI), white blood cells (WBC), C-reactive protein (CRP) levels, comorbidities and wound closure methods were recorded. Patients were divided into the study group and control group according to the treatment modality. Patients in the study group received the combination treatment of ALBC and VAC, while patients in the control group received single VAC treatment. Clinical endpoints were assessed and compared between the two groups, including wound complete healing time and complications after operation. All patients were followed-up 6 months postoperation. Results showed that the mean healing time of the study group (44.20 ± 16.72 days) was shorter than that of the control group (64.00 ± 29.85 days) (P < .05). The infection rate of the study group on the 10th day postoperation was lower than that of the control group (6.67%, 47.06%, P < .05). And there were no significant statistical differences between the two groups in terms of bleeding and necrosis complications postoperation (P = .603, P = .603). Based on the findings, we conclude that the application of ALBC combined with VAC can facilitate wound healing in Wagner 3-4 DFUs patients. It can help to control wound infections and shorten wound healing time.

Negative pressure wound therapy in surgical practice: an Institutional experience from a tertiary centre of North India

&lt;b&gt;Introduction:&lt;/b&gt; Negative pressure wound therapy (NPWT) has been suggested as a gold standard for managing complex wounds and to reduce the time of healing and overall morbidity and mortality of the patient. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Aim:&lt;/b&gt; We have done a retrospective study to observe the outcome in patients managed with negative pressure wound therapy for varied etiologies. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Methods:&lt;/b&gt; Patients with complicated wounds including lower limb wounds post-debridement, upper limb wounds post-debridement, postoperative abdominal wound dehiscence, abdominal and chest abscess wounds post-debridement and amputation stumps, managed with negative pressure wound therapy were studied on the basis of wound outcome, total hospital stay, days of NPWT application and pressure and mode of NPWT. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Results:&lt;/b&gt; A total of 42 patients with complicated wounds were included in the study. Mean hospital stay was 16.2 days and mean NPWT application time was 8.29 days with NPWT being applied on average for 3.91 days post-procedure like debridement or amputation or after wound dehiscence in which debridement was not done. As many as 41.5% of wounds were closed with suturing, 48.8% healed by secondary intention and 9.8% were covered with split-thickness skin grafts. A significant observation was made for lower pressure being used for abdominal wound dehiscence (75 mmHg) compared to other wounds on limbs (mean 98.33 mmHg) (P &lt; 0.001). Re-debridement after the 1st cycle of NPWT was needed in 40% of wounds managed with intermittent mode compared to 6.2% in continuous mode (P = 0.028). &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Conclusion:&lt;/b&gt; NPWT can reduce and manage wound complications with improvement in the quality of life of patients when used at an appropriate time with knowledge of its mechanism and functionality.

A promising contribution to negative pressure wound therapy in treatment of prosthetic joint infection. Discussion based on case report

INTRODUCTION AND IMPORTANCE

Although a significant number of periprosthetic joint infection cases and well-proven algorithm of its cure are available, there still is a potential to make a more justified decision and thus improve treatment result.

CASE PRESENTATION

This paper presents a case report of late simultaneous Prosthetic Joint Infection of both knees.Clinical discussion dedicates to the possible contribution of Negative Pressure Wound Therapy in treatment of Prosthetic Joint Infection.

CONCLUSION

We conceive the role of NPWT in the treatment of PJI to be underestimated to date and should be assessed in controlled trial.

Cost analysis of negative-pressure wound therapy versus standard treatment of acute conflict-related extremity wounds within a randomized controlled trial

Background

Clinical outcomes after negative-pressure wound therapy (NPWT) and standard treatment of conflict-related extremity wounds are similar. In resource-limited settings, cost affects the choice of treatment. We aimed to estimate treatment-related costs of NPWT in comparison with standard treatment for conflict-related extremity wounds.

Methods

We derived outcome data from a randomized, controlled superiority trial that enrolled adult (≥ 18 years) patients with acute (≤ 72 h) conflict-related extremity wounds at two civilian hospitals in Jordan and Iraq. Primary endpoint was mean treatment-related healthcare costs (adjusted to 2019 US dollars).

Results

Patients were enrolled from June 9, 2015, to October 24, 2018. A total of 165 patients (155 men [93.9%]; 10 women [6.1%]; and median [IQR] age, 28 [21–34] years) were included in the analysis. The cost per patient treated with NPWT was $142 above that of standard treatment. Overall, results were robust in a sensitivity analysis.

Conclusions

With similar clinical outcomes compared to standard care, our results do not support the use of NPWT in routine treatment of conflict-related extremity wounds at civilian hospitals in resource scarce settings.

Trial registration NCT02444598.

NPWT Resource Use Compared With Conventional Wound Treatment in Subcutaneous Abdominal Wounds With Healing Impairment After Surgery: SAWHI Randomized Clinical Trial Results

OBJECTIVE

To compare resource utilization of NPWT and CWT for SAWHI after surgery.

SUMMARY OF BACKGROUND DATA

NPWT is widely used in the management of complex wounds but high-level evidence of its resource use remains sparse.

METHODS

The multicenter, multinational, randomized clinical SAWHI study enrolled a total of 539 consecutive, compliant adult patients with SAWHI after surgery without fascial dehiscence between August 2, 2011, and January 31, 2018. Patients were randomly assigned to NPWT and CWT stratified by study site and wound size using a centralized web-based tool. Evaluation of direct resource use comprised inpatient and outpatient time, personnel and material for wound treatment, and associated wound-related procedures. The resource use analysis was primarily based on the per protocol population (NPWT 157; CWT 174).

RESULTS

Although treatment length within 42 days was significantly shorter in the NPWT arm {Mean [Standard deviation (SD)] NPWT 22.8 (13.4); CWT 30.6 (13.3); P < 0.001 U-test}, hospitalization time was shorter with CWT [Mean (SD) NPWT 13.9 (11.1); CWT 11.8 (10.8); P = 0.047 U-test]. Significantly more study participants were outpatient with CWT [N=167 (96.0%)] than with NPWT [N = 140 (89.2%) (P = 0.017)]. Time for dressing changes per study participant [Mean (SD) (min) NPWT N = 133, 196 (221.1); CWT N = 152, 278 (208.2); P < .001 U-test] and for wound-related procedures [Mean (SD) (min) NPWT 167 (195); CWT 266 (313); P < 0.001 U-test] was significantly lower with NPWT.

CONCLUSIONS

NPWT reduces resource use and maybe an efficient treatment alternative to CWT for SAWHI after surgery.

Consensus on the health education of home-based negative pressure wound therapy for patients with chronic wounds: a modified Delphi study

Background

The study aimed to develop consensus on the components of health education of home-based negative pressure wound therapy (NPWT) for patients with chronic wounds.

Methods

A Delphi method was used to achieve consensus on the components of health education and 75% agreement and coefficient of variation (CV) <0.25 were used as cutoff. Sixteen experts were recruited purposefully to finish this study.

Results

Two rounds of consultation were implemented. Consensus was achieved on 36 of the 42 statements. The final agreed list of statements represented three domains: health education before carrying out home-based NPWT, health education for the treatment day of NPWT at hospital and health education for NPWT at home.

Conclusions

This study was the first attempt to develop consensus on the comprehensive components of health education of home-based NPWT for patients with chronic wounds. According to the established framework and components of health education, wound professionals can safely and effectively implement health education of home-based NPWT for patients with chronic wounds and improve their self-care ability and treatment experience at home.

Low-vacuum negative pressure wound therapy protocol for complex wounds with exposed vessels

OBJECTIVE

Treating high-risk surgical patients with complex wounds over exposed blood vessels is a challenge. Guided wound healing may be the only treatment possible. Negative pressure wound therapy (NPWT) is not recommended in these cases. The authors challenged these current recommendations and share their preliminary experience.

METHOD

The authors adapted a NPWT protocol that uses low-vacuum continuous pressure (-80mmHg) with a silicone sheath and gauze/foam dressing between the wound bed and the device. They monitored the clinical features of patients' wounds to detect bleeding/ischaemia early on. Dressings were changed every 72-96 hours.

RESULTS

This protocol was followed in five male patients (aged 23-68 years) with complex wounds over exposed vessels. Two cases were foot crush injuries, one midfoot amputation, one hand self-subamputation and one vascular bypass infection. Comorbidities included monoarterial limbs/stump, severe arteriopathy and psychiatric disorder. The exposed vessels were femoral, radial and ulnar, anterior and posterior tibial arteries and veins. Mean treatment lasted 37 days (range 20-61 days). No episodes of severe bleeding/ischaemia of the extremities were observed. Treatment was discontinued once debridement was complete and granulation tissue allowed spontaneous closure/grafting. All wounds appeared stable at 1-year follow-up.

CONCLUSION

The low-vacuum NPWT protocol was successful in solving five difficult cases. This regimen reduces risks associated with NPWT use on wounds with exposed vessels. The authors believe further validation is required to strengthen the evidence. However, preliminary data are encouraging and might help to change future NPWT recommendations by extending the indications for its use to exposed vessels.

Clinical Uses of NPWT with Irrigation of Normal Saline in Diabetic Foot Ulcer: Outcome Assessed by DEPA Score

Introduction

Diabetic foot ulcer (DFU) is a common complication of uncontrolled diabetes. Negative pressure wound therapy (NPWT) with irrigation of normal saline is one of the methods for wound care and dressing techniques in DFU. Wound assessment is another aspect of DFU management for deciding whether the wound is prepared or not for coverage. The present study uses DEPA score as a wound assessment tool in DFU.

Materials and Methods

This case series include 11 patients with DFU who were treated using NPWT with simultaneous irrigation of normal saline.

Results

All 11 patients were male and age more than 60. Most patients have duration of diabetes for less than 10 years. Staphylococcus aureus (n = 5, 45.4%) was most common bacterial flora. Most patients in series presented with DEPA score more than 7 and after application of NPWT instillation therapy significant improvement seen with score in most of the patient with DEPA score below 6. Mean time for NPWT (irrigation) application was 15 days. Mean time of wound preparation was 18.7 days. Final surgical procedures executed in all patients, split skin grafting performed in 7 patients. 4 patients had wound coverage by reverse sural flap (2), medial plantar flap (1) and local flap coverage (1).

Conclusion

NPWT with normal saline irrigation is an effective method of wound preparation in DFU. DEPA score is an important tool for assessment of wound preparation which gives exact information for timing of wound coverage once diabetic foot wound is prepared.

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.

Retained Negative Pressure Wound Therapy Foams as a Cause of Infection Persistence

Significance: Negative pressure wound therapy (NPWT) has become a valuable adjunct in the treatment of acute and chronic wounds in several surgical disciplines. Retained foams are among its side effects, and they pose a rare but devastating complication at the site of this therapy, which might be associated with wound-healing complications, infection persistence, repeated surgical revisions, and prolonged antibiotic courses. Recent Advances: In the past 15 years, an increasing number of studies have identified this potential problem. Although the exact incidence remains unknown, initial studies have indicated rates of up to 10% in large collectives being treated by NPWT. Critical Issues: The lack of radiopaque markers does not allow for the visual control of retained foams using plain radiographs. Further imaging methods (e.g., CT and MRI) also do not help in adequate differential diagnosis. The lack of routine documentation of the number, type, and localization of the inserted foam(s) and unplanned surgery with a different surgical team pose risk factors for foam retainment. Future Directions: Introducing new documentation records for wounds treated with NPWT is recommended. At foam removal, all dressing materials should be examined for integrity. The development of foams with radiopaque markers by the industry, such as those routinely used in surgical gauze swabs, might also be a useful step to minimize the risk of foam retainment within wounds.

The use of negative pressure wound therapy for fracture-related infections following internal osteosynthesis of the extremity: A systematic review

This study aimed to systematically review the current literature on studies using negative pressure wound therapy (NPWT) or dressings following fracture-related infection (FRI) in internal osteosynthesis of the extremity. Articles were analyzed on fracture and wound healing and included when comparing or describing the use of either NPWT or dressings in FRI. We conducted a systematic literature search in four electronic databases: Embase, Medline, the Cochrane Library, and Scopus. The studies were screened by two authors using Covidence.org and evaluated for risk of bias. A total of 8576 records were identified. No articles compared NPWT to dressings. Seven case reports and three case series included a total of 115 patients treated for FRI. Fracture healing was achieved in 21 out of 67 patients treated with NPWT (4 amputations and 46 not described) and all 48 patients in the dressing group (4 patients needed additional sequestrectomy procedures). Five studies did not describe fracture healing. In 57 out of 67 patients treated with NPWT, the wounds were described as healed, closed, or requiring soft tissue reconstruction (4 amputations and six lacking description). The dressing group had complete wound coverage in 18 patients and partial coverage in 30 patients. Studies were generally at high risk of bias because of insufficient descriptions of both patient demographics and outcomes. No studies compared NPWT to dressings, and the existing literature is at high risk of bias. The included studies were of low-level evidence. NPWT can be neither recommended nor advised against to cover infected osteosynthesis.

Wound healing: potential therapeutic options

This review highlights the range of therapeutic options available to clinicians treating difficult-to-heal wounds. While certain treatments are established in daily clinical practice, most therapeutic interventions lack robust and rigorous data regarding their efficacy, which would help to determine when, and for whom, they should be used. The purpose of this review is to give a broad overview of the available interventions, with a brief summary of the evidence base for each intervention.

Alternative Approaches for the Management of Diabetic Foot Ulcers

Diabetic foot ulcers (DFU) represent a growing public health problem. The emergence of multidrug-resistant (MDR) bacteria is a complication due to the difficulties in distinguishing between infection and colonization in DFU. Another problem lies in biofilm formation on the skin surface of DFU. Biofilm is an important pathophysiology step in DFU and may contribute to healing delays. Both MDR bacteria and biofilm producing microorganism create hostile conditions to antibiotic action that lead to chronicity of the wound, followed by infection and, in the worst scenario, lower limb amputation. In this context, alternative approaches to antibiotics for the management of DFU would be very welcome. In this review, we discuss current knowledge on biofilm in DFU and we focus on some new alternative solutions for the management of these wounds, such as antibiofilm approaches that could prevent the establishment of microbial biofilms and wound chronicity. These innovative therapeutic strategies could replace or complement the classical strategy for the management of DFU to improve the healing process.

Can Intralesional Epidermal Growth Factor Reduce Skin Graft Applications in Patients with Diabetic Foot Ulcer?

BACKGROUND

Diabetic foot ulcer (DFU) is a serious health problem. Major amputation increases the risk of mortality in patients with DFU; therefore, treatment methods other than major amputation come to the fore for these patients. Graft applications create an appropriate environment for the reproduction of epithelial cells. Similarly, epidermal growth factor (EGF) also stimulates epithelization and increases epidermis formation. In this study, we aimed to compare patients with DFU treated with EGF and those treated with a split-thickness skin graft.

METHODS

Patients who were treated for DFU in the general surgery clinic were included in the study. The patients were evaluated retrospectively according to their demographic characteristics, wound characteristics, duration of treatment, and treatment modalities.

RESULTS

There were 26 patients in the EGF group and 21 patients in the graft group. The mean duration of treatment was 7 weeks (4-8 weeks) in the EGF group and 5.3 weeks (4-8 weeks) in the graft group (P < .05). In the EGF group, wound healing could not be achieved in one patient during the study period. In the graft group, no recovery was achieved in three patients (14.2%) in the donor site. Graft loss was detected in four patients (19%), and partial graft loss was observed in three patients (14.2%). The DFU of these patients were on the soles (85.7%). These patients have multiple comorbidities.

CONCLUSIONS

EGF application may be preferred to avoid graft complications in the graft area and the donor site, especially in elderly patients with multiple comorbidities and wounds on the soles.

Vacuum-Assisted Closure with Temporalis Muscle Reconstruction for Recurrent Scalp Erosion Following Deep Brain Stimulation: A Case Report

BACKGROUND

Scalp erosion is not an uncommon complication of deep brain stimulation (DBS) surgery. Although various methods have been proposed to prevent and manage complications, there are still challenges. We introduce a case of recurrent scalp erosion after DBS surgery treated with vacuum-assisted closure.

CASE DESCRIPTION

This article reports the case of a patient who underwent DBS for advanced Parkinson's disease and suffered from recurrent scalp erosion with device extrusion through the skin. Scalp erosion occurred 2 years after DBS and repeated improvement and deterioration despite scalp reconstruction using a skin flap. We opened the wound and performed temporal muscle reconstruction to cover the burr hole site, and we changed the exposed cable and applied vacuum-assisted closure. During the follow-up period, no signs of erosion or infection occurred, and DBS efficacy was preserved.

CONCLUSION

To date, the available management strategies for scalp erosion after DBS are revision with debridement and scalp reconstruction using skin flaps or skin grafts. However, if erosion occurs repeatedly despite the above management strategies, vacuum-assisted closure with temporalis muscle reconstruction could be a suitable option. We suggest that if the condition of the scalp is weakened, it is worth considering this approach preferentially.

Diagnosis and treatment impacts on wound care efficiency drivers: real-world analysis

Objective: The prevalence and economic burden of wounds are growing. Any wound has the potential to become hard-to-heal and require frequent care. Clinicians need to find ways to absorb demand on services without compromising outcomes. Drivers of wound care efficiency-time-to-heal, frequency of dressing change and the incidence of complications-can be evaluated to shape future wound management. A survey of wound care was conducted by clinicians from five centres in Sweden over a one-week period, during which clinicians documented every wound once. At the time of surveying, 49% of wounds were considered to be improving, infection incidence was 11.7% and dressings were changed a mean of 2.2 times per week, with highly exuding wounds changed 6.9 times per week. The data highlighted the importance of diagnosing patient and wound characteristics in selecting treatments and organising care. Recognised gaps in diagnoses potentially identify opportunities to influence healing, complication incidence and intensity of nursing, thus reducing demand on resources. In conclusion, this survey highlights opportunities to reduce the burdens these drivers present. Through improved diagnosis and alignment to recognised care pathways, there is potential to improve patient outcomes and alleviate the strains placed upon wound care providers.

Negative pressure wound therapy-two novel approaches to healing dehisced vascular bypass wounds

The use of negative pressure wound therapy (NPWT) in surgical wound healing by secondary intention is well known. Its use in healing dehisced vascular bypass wounds is contraindicated by manufacturers due to exposed vasculature and risk of bleeding. There is an increasing body of knowledge to support the use of NPWT in vascular wounds in order to prevent graft excision and the need for flap closure. This paper reports the use of two different approaches using NPWT to heal dehisced, infected vascular groin bypass wounds in two patients. Both patients had lower limb bypass using Dacron (Vascutek Ltd., UK) grafts and subsequently became infected, dehisced and required debridement. Following debridement, graft was visible in the wound bed and NPWT was applied to facilitate healing. Case one had polyurethane (black) foam and a layer of petroleum-impregnated cellulose acetate mesh to prevent adherence to the graft. Case two had polyvinyl alcohol (white) (PVA) foam applied to the wound. The PVA foam was used in Case two due to pain at dressing changes. Negative pressure was initially -25mmHg but increased gradually to -125mmHg and -150mmHg, respectively, the therapeutic pressure for the respective foams. Dressings were changed every 48-72 hours and infection treated with antibiotics as appropriate. After eight days and 28 days of NPWT, respectively, graft was no longer visible. No significant bleeding was noted. These two case studies would suggest that, with precautions taken to protect the vasculature, the use of NPWT in healing dehisced vascular groin wounds is an appropriate treatment.

Cryptococcus neoformans osteomyelitis of the calcaneus: Case report and literature review

Cryptococcus neoformans is an encapsulated, yeast-like fungus that can cause a systemic mycosis, particularly in immunocompromised patients. Disseminated infections typically affect the central nervous system, and osseous lesions are infrequent. Only 5%–10% of disseminated cryptococcosis involves bones. A 69-year-old female presented pain, swelling, and a soft tissue mass in her right lateral hindfoot. Her medical history included a kidney transplant (10 years earlier) secondary to chronic disease due to IgA nephropathy. The patient underwent an excisional biopsy, surgical debridement, and secondarily negative pressure wound therapy to achieve skin closure. Biopsy revealed a rare Cryptococcus neoformans osteomyelitis of the calcaneus. The patient then received IV treatment with liposomal amphotericin B at 3 mg/kg/d for 25 days. In conclusion, we present a case of cryptococcal osteomyelitis which, although not a frequent disease, must be considered as one of the differential diagnoses of osteolytic osseous lesions in patients with chronic osteomyelitis. Cryptococcus neoformans may be a potential cause of below-knee infection, mainly in immunocompromised patients.

Expanded negative pressure wound therapy in healing diabetic foot ulcers: a prospective randomised study

OBJECTIVE

This study aims to evaluate the benefits of treating diabetic foot ulcers (DFU) through a revised procedure using the mechanisms underlying negative pressure wound therapy (NPWT) in such a way as to achieve reduced and more evenly distributed lateral tension lines across the wound.

METHOD

Patients with type 2 diabetes were assessed for elegibility. Included patients were divided randomly into two groups: the NPWT control group and the NPWT+ group. Patients in the NPWT control group were treated in the traditional manner: wounds were covered with foams shaped to fit the wound precisely. In the NPWT+ group, foams were shaped to fit the wound precisely, and an additional foam was then wrapped around the foot.

RESULTS

Some 85 patients were assessed for eligibility; 59 were randomised into two groups: 29 patients in the NPWT+ group and 30 patients in the NPWT group. The primary objective was median healing time (NPWT+ 19 days, interquartile ratio (IQR) 7.5; NPWT 33 days, IQR 16; p<0.00001), and complete wound healing at three weeks (NPWT+ 55.20% NPWT 26.70% p=0.02). Secondary endpoints included number of major amputations (none in either group) and number of infections (NPWT+ 3.44% of patients, NPWT 6.66% of patients; p=0.57).

CONCLUSION

Our initial findings show that this treatment significantly reduced wound closure times and accelerated healing in DFUs. It also demonstrated promising improvements in healing rates, with no significant increase in wound complications.

Consensus on the application of negative pressure wound therapy of diabetic foot wounds

Because China is becoming an aging society, the incidence of diabetes and diabetic foot have been increasing. Diabetic foot has become one of the main health-related killers due to its high disability and mortality rates. Negative pressure wound therapy (NPWT) is one of the most effective techniques for the treatment of diabetic foot wounds and great progress, both in terms of research and its clinical application, has been made in the last 20 years of its development. However, due to the complex pathogenesis and management of diabetic foot, irregular application of NPWT often leads to complications, such as infection, bleeding and necrosis, that seriously affect its treatment outcomes. In 2020, under the leadership of Burns, Trauma and Tissue Repair Committee of the Cross-Straits Medicine Exchange Association, the writing group for ‘Consensus on the application of negative pressure wound therapy of diabetic foot wounds’ was established with the participation of scholars from the specialized areas of burns, endocrinology, vascular surgery, orthopedics and wound repair. Drawing on evidence-based practice suggested by the latest clinical research, this consensus proposes the best clinical practice guidelines for the application and prognostic evaluation of NPWT for diabetic foot. The consensus aims to support the formation of standardized treatment schemes that clinicians can refer to when treating cases of diabetic foot.

Negative Pressure Wound Therapy vs Conventional Wound Treatment in Subcutaneous Abdominal Wound Healing Impairment: The SAWHI Randomized Clinical Trial

Question

Is negative pressure wound therapy (NPWT) an effective and safe treatment option for subcutaneous abdominal wound healing impairment (SAWHI) after surgery?

Findings

In the randomized clinical SAWHI study that included 507 adults, wounds were closed significantly faster and more often in the NPWT arm (36.1 days for 92 of 256 study participants) than with conventional wound treatment (39.1 days for 54 of 251 participants). The number of participants with wound-related adverse events was higher in the NPWT arm (48 of 234) than in the conventional wound treatment arm (27 of 201).

Meaning

For SAWHI after surgery, NPWT is an effective treatment alternative to conventional wound treatment but causes more wound-related adverse events.

Importance

Negative pressure wound therapy (NPWT) is an established treatment option, but there is no evidence of benefit for subcutaneous abdominal wound healing impairment (SAWHI).

Objective

To evaluate the effectiveness and safety of NPWT for SAWHI after surgery in clinical practice.

Design, Setting, and Participants

The multicenter, multinational, observer-blinded, randomized clinical SAWHI study enrolled patients between August 2, 2011, and January 31, 2018. The last follow-up date was June 11, 2018. The trial included 34 abdominal surgical departments of hospitals in Germany, Belgium, and the Netherlands, and 539 consecutive, compliant adult patients with SAWHI after surgery without fascia dehiscence were randomly assigned to the treatment arms in a 1:1 ratio stratified by study site and wound size using a centralized web-based tool. A total of 507 study participants (NPWT, 256; CWT, 251) were assessed for the primary end point in the modified intention-to-treat (ITT) population.

Interventions

Negative pressure wound therapy and conventional wound treatment (CWT).

Main Outcomes and Measures

The primary outcome was time until wound closure (delayed primary closure or by secondary intention) within 42 days. Safety analysis comprised the adverse events (AEs). Secondary outcomes included wound closure rate, quality of life (SF-36), pain, and patient satisfaction.

Results

Of the 507 study participants included in the modified ITT population, 287 were men (56.6%) (NPWT, 155 [60.5%] and CWT, 132 [52.6%]) and 220 were women (43.4%) (NPWT, 101 [39.5%] and CWT 119 [47.4%]). The median (IQR) age of the participants was 66 (18) years in the NPWT arm and 66 (20) years in the CWT arm. Mean time to wound closure was significantly shorter in the NPWT arm (36.1 days) than in the CWT arm (39.1 days) (difference, 3.0 days; 95% CI 1.6-4.4; P < .001). Wound closure rate within 42 days was significantly higher with NPWT (35.9%) than with CWT (21.5%) (difference, 14.4%; 95% CI, 6.6%-22.2%; P < .001). In the therapy-compliant population, excluding study participants with unauthorized treatment changes (NPWT, 22; CWT, 50), the risk for wound-related AEs was higher in the NPWT arm (risk ratio, 1.51; 95% CI, 0.99-2.35).

Conclusions and Relevance

Negative pressure wound therapy is an effective treatment option for SAWHI after surgery; however, it causes more wound-related AEs.

Trial Registration

ClinicalTrials.gov Identifier: NCT01528033

How influential is the stiffness of the foam dressing on soft tissue loads in negative pressure wound therapy?

Negative pressure wound therapy (NPWT) is an established adjunctive modality for treatment of both acute and chronic wounds. However, little is known about the optimal settings and combination of treatment parameters and importantly, how these translate to target tissue strains and stresses that would result the fastest healing and buildup of good-quality tissues. Here we have used a three-dimensional open wound computational (finite element) model that contains viscoelastic skin, adipose and skeletal muscle tissue components for determining the states of tissue strains and stresses in and around the wound when subjected to NPWT with foam dressings of varying stiffnesses. We found that the skin strain state is considerably more sensitive to the pressure level than to the stiffness of the foam dressing within a 8.25 to 99 kPa range which covers the current industry standard. Accordingly, peri-wound skin strains and stresses which stimulate cell proliferation/migration and angiogenesis and thereby, healing of the wound, can be more effectively controlled by adjusting the pressure level than by varying the stiffness of the foam dressing.

Comparison of Healthcare Costs Associated With Patients Receiving Traditional Negative Pressure Wound Therapies in the Post-Acute Setting

Objective

A retrospective national insurance claims database analysis evaluated total and wound-related costs for acute and chronic wound patients treated with negative pressure wound therapy (NPWT), comparing a product specific NPWT (NPWT-K) to other NPWT systems (NPWT-O).

Methods

Patients with one or more NPWT claims between January 2016 and September 2018 in an outpatient setting with continuous medical and pharmacy benefits for six months before the initial (index) NPWT claims and 12 months post index were assessed. The cohorts were propensity score matched based on age, gender, comorbidities, and payer type. Each cohort included 3,368 patients after matching. Costs were evaluated at 30 days, three months, and 12 months after initial NPWT placement. Hospital admission rates, emergency room (ER) visits, and NPWT device switching were evaluated at 30 days. Differences were analyzed by t-test and chi-square test.

Results

At 30 days, wound-related costs were $8,583 and $11,334, and total cost to treat was $17,809 and $24,405 for NPWT-K and NPWT-O, respectively (p < 0.0001). NPWT-O patients had higher NPWT, wound-related, and total costs across all time periods, as well as a longer average length of therapy (p = .0039). There was no statistical difference in 30-day hospital admissions (p = 0.089); although 30-day ER visits were higher for NPWT-K (4.9% vs. 3.3%, p = 0.0007). A higher degree of switching from NPWT-O to NPWT-K occurred at 30 days (NPWT-O 2.5% vs. 0.4%, p < 0.0001).

Conclusions

This comparative effectiveness analysis indicates differences remain across NPWT suppliers in wound-related and total cost to treat for patients who receive durable NPWT in the outpatient setting.

A novel system for dynamic stretching of cell cultures reveals the mechanobiology for delivering better negative pressure wound therapy

Serious wounds, both chronic and acute (e.g., surgical), are among the most common, expensive and difficult-to-treat health problems. Negative pressure wound therapy (NPWT) is considered a mainstream procedure for treating both wound types. Soft tissue deformation stimuli are the crux of NPWT, enhancing cell proliferation and migration from peri-wound tissues which contributes to healing. We developed a dynamic stretching device (DSD) contained in a miniature incubator for applying controlled deformations to fibroblast wound assays. Prior to the stretching experiments, fibroblasts were seeded in 6-well culture plates with elastic substrata and let to reach confluency. Squashing damage was then induced at the culture centers, and the DSD was activated to deliver stretching regimes that represented common clinical NPWT protocols at two peak strain levels, 0.5% and 3%. Analyses of the normalized maximal migration rate (MMR) data for the collective cell movement revealed that for the 3% strain level, the normalized MMR of cultures subjected to a 0.1 Hz stretch frequency regime was ~ 1.4 times and statistically significantly greater (p < 0.05) than that of the cultures subjected to no-stretch (control) or to static stretch (2nd control). Correspondingly, analysis of the time to gap closure data indicated that the closure time of the wound assays subjected to the 0.1 Hz regime was ~ 30% shorter than that of the cultures subjected to the control regimes (p < 0.05). Other simulated NPWT protocols did not emerge as superior to the controls. The present method and system are a powerful platform for further revealing the mechanobiology of NPWT and for improving this technology.

Perspectives on the Process of Negative Pressure Wound Therapy at Home in Patients With Chronic Wound: A Qualitative Descriptive Study

The purpose of this study was to explore the experience of negative pressure wound therapy (NPWT) at home among Chinese chronic wound patients. Qualitative descriptive study design was adopted, and qualitative data were collected through semistructured in-depth interviews. A purposive, sampling method was used. Informants were recruited from one single wound healing center of a teaching hospital and were interviewed following one course of NPWT at home. A thematic content analysis was undertaken in the framework of input-process-output theory to guide analysis. Of the 13 participants interviewed, 9 were female and 4 were male with an age ranging from 20 to 69 years. Two major categories with their corresponding codes were identified. The first, positive experience, had 6 codes: high-degree identity and feeling hope (input); easy operation and convenience (process); improvement of symptoms and effective treatment (output). The second category, negative experience, had 11 codes: high expenditure, defects of the NPWT device, health education deficiency, and lack of independence and rationales in making decision of NPWT (input); poor communication with wound professionals, unexpected circumstances, therapeutic side effects, and a change of self-image (process); impact on physical symptoms and daily life, impact on social activities, and impact on psychological well-being (output). Patients considered the NPWT at home as a promising regimen, but they also had a feeling of not being prepared and lack of health education to make medical decision independently. The participants' perceptions and experiences would provide valuable information to promote the intervention program of health education and advance service process optimization.

Acceleration of Skin Wound-Healing Reactions by Autologous Micrograft Tissue Suspension

Background and objectives: Skin grafting is a method usually used in reconstructive surgery to accelerate skin regeneration. This method results frequently in unexpected scar formations. We previously showed that cutaneous wound-healing in normal mice is accelerated by a micrograft (MG) technique. Presently, clinical trials have been performed utilizing this technology; however, the driving mechanisms behind the beneficial effects of this approach remain unclear. In the present study, we focused on five major tissue reactions in wound-healing, namely, regeneration, migration, granulation, neovascularization and contraction. Methods: Morphometrical analysis was performed using tissue samples from the dorsal wounds of mice. Granulation tissue formation, neovascularization and epithelial healing were examined. Results: The wound area correlated well with granulation sizes and neovascularization densities in the granulation tissue. Vascular distribution analysis in the granulation tissue indicated that neovessels extended and reached the subepidermal area in the MG group but was only halfway developed in the control group. Moreover, epithelialization with regeneration and migration was augmented by MG. Myofibroblast is a known machinery for wound contraction that uses α-smooth muscle actin filaments. Their distribution in the granulation tissue was primarily found beneath the regenerated epithelium and was significantly progressed in the MG group. Conclusions: These findings indicated that MG accelerated a series of wound-healing reactions and could be useful for treating intractable wounds in clinical situations.

Negative pressure wound therapy versus standard treatment in patients with acute conflict-related extremity wounds: a pragmatic, multisite, randomised controlled trial

BACKGROUND

In armed conflict, injuries among civilians are usually complex and commonly affect the extremities. Negative pressure wound therapy (NPWT) is an alternative to standard treatment of acute conflict-related extremity wounds. We aimed to compare the safety and effectiveness of NPWT with that of standard treatment.

METHODS

In this pragmatic, randomised, controlled superiority trial done at two civilian hospitals in Jordan and Iraq, we recruited patients aged 18 years or older, presenting with a conflict-related extremity wound within 72 h after injury. Participants were assigned (1:1) to receive either NPWT or standard treatment. We used a predefined, computer-generated randomisation list with three block sizes. Participants and their treating physicians were not masked to treatment allocation. The primary endpoint was wound closure by day 5. The coprimary endpoint was net clinical benefit, defined as a composite of wound closure by day 5 and freedom from any bleeding, wound infection, sepsis, or amputation of the index limb. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT02444598, and is closed to accrual.

FINDINGS

Between June 9, 2015, and Oct 24, 2018, 174 patients were randomly assigned to either the NPWT group (n=88) or the standard treatment group (n=86). Five patients in the NPWT group and four in the standard treatment group were excluded from the intention-to-treat analysis. By day 5, 41 (49%) of 83 participants in the NPWT group and 49 (60%) of 82 participants in the standard treatment group had closed wounds, with an absolute difference of 10 percentage points (95% CI -5 to 25, p=0·212; risk ratio [RR] 0·83, 95% CI 0·62 to 1·09). Net clinical benefit was seen in 33 (41%) of 81 participants in the NPWT group and 34 (44%) of 78 participants in the standard treatment group, with an absolute difference of 3 percentage points (95% CI -12 to 18, p=0·750; RR 0·93, 95% CI 0·65 to 1·35). There was one in-hospital death in the standard treatment group and none in the NPWT group. The proportion of participants with sepsis, bleeding leading to blood transfusion, and limb amputation did not differ between groups.

INTERPRETATION

NPWT did not yield superior clinical outcomes compared with standard treatment for acute conflict-related extremity wounds. The results of this study not only question the use of NPWT, but also question the tendency for new and costly treatments to be introduced into resource-limited conflict settings without supporting evidence for their effectiveness. This study shows that high-quality, randomised trials in challenging settings are possible, and our findings support the call for further research that will generate context-specific evidence.

FUNDING

The Stockholm County Council, the Swedish National Board of Health and Welfare, and Médecins Sans Frontières.

ALGINATE versus NPWT in the Preparation of Surgical Excisions for an STSG: ATEC Trial

Supplemental Digital Content is available in the text.

A calcium alginate dressing (ALGINATE) and negative pressure wound therapy (NPWT) are frequently used to treat wounds which heal by secondary intention. This trial compared the healing efficacy and safety of these 2 treatments.

Negative Pressure Wound Therapy in Pyoderma Gangrenosum Treatment

Patient: Male, 83-year-old

Final Diagnosis: Pyoderma gangrenosum

Symptoms: Infection

Medication: —

Clinical Procedure: Negative pressure wound therapy

Specialty: Dermatology • Geriatrics • Palliative Medicine • Surgery

Preparation and biological evaluation of a novel agarose-grafting-hyaluronan scaffold for accelerated wound regeneration

At present, seeking an effective dressing for wound regeneration has drawn considerable interest. In this paper, a novel agarose-grafting-hyaluronan (Ag-g-HA) scaffold was synthesized for rapid wound healing. Elemental analysis results showed that the HA grafting rate of Ag-g-HA was ∼69%. Ag-g-HA remained bioactive to accelerate cell proliferation and stimulate secretion of TNF-α for macrophagocyte RAW 264.7, and collagen I and collagen III for fibroblast 3T3. An i n vivo study demonstrated that Ag-g-HA showed a faster repair cycle and a better skin histological structure for a full-thickness skin defect. The collagen I, collagen III and TNF-α secreted by mice for Ag-g-HA were similiar to HA. Ag-g-HA showed a similiar biological activity to HA but had a longer degradation time through its improved insolubility. These findings demonstrate that the Ag-g-HA scaffold accelerated wound healing, and could be a promising novel scaffold for tissue engineering and regenerative medicine.

Heel Pressure Injuries: Consensus-Based Recommendations for Assessment and Management

Significance: A systematic approach to develop experts-based recommendations could have a favorable impact on clinical problems characterized by scarce and low-quality evidence as heel pressure ulcers. Recent Advances: A systematic approach was used to conduce a formal consensus initiative. A multidisciplinary panel of experts identified relevant clinical questions, performed a systematic search of the literature, and created a list of statements. GRADE Working Group guidelines were followed. An independent international jury reviewed and voted recommendations for clinical practice. Consent was developed according to Delphi rules and GRADE method was used to attribute grade of strength. Critical Issues: The extensive search of the literature retrieved 42 pertinent articles (26 clinical studies, 7 systematic reviews or meta-analysis, 5 other reviews, 2 consensus-based articles, and 2 in vitro studies). Thirty-five recommendations and statements were created. Only 1 of 35, concerning ankle-brachial pressure index reliability in diabetic patients, was rejected by the panel. No sufficient agreement was achieved on toe brachial index test to rule out the orphan heel syndrome, removing dry eschar in adult patients without vascular impairment, and using an antimicrobial dressing in children with infected heel pressure injuries. Eleven recommendations were approved with a weak grade of strength. Experts strongly endorsed 20 recommendations. Offloading, stages I and II pressure injuries, and referral criteria were areas characterized by higher level of agreement. Future Directions: We believe that the results of our effort could improve practice, especially in areas where clear and shared opinions emerged. Barriers and limits that could hinder implementation are also discussed in the article.

NPWT in diabetic foot wounds-a systematic review and meta-analysis of observational studies

PURPOSE

Negative-pressure wound therapy (NPWT) is an adjunct modality in diabetic foot ulcerations (DFUs). Randomized controlled trials (RCTs) have shown its advantage over standard approaches; however, data from observational studies remain scarce.We performed a systematic review of observational non-RCTs evaluating NPWT efficacy and safety in patients with DFU.

METHODS

Electronic databases were searched for observational studies involving NPWT. The results of single-arm studies were presented as percentages of patients with the outcome of interest. A meta-analysis of comparative studies provided point estimates of outcomes. Continuous outcomes were reported as either weighted or standardized mean differences and dichotomous data as relative risks (RR).

RESULTS

The search identified 16 relevant observational studies, 12 single-arm, and 4 comparative, reporting on a total of 18,449 patients with DFU, of whom 1882 were managed with NPWT. In the NPWT-treated patients, ulcers were larger (average size range 6.6-27.9 cm²), as compared with controls (≤3 cm²). The pooled results showed healing and major amputation in 51% and 5% of NPWT patients, respectively. The meta-analysis of comparative studies revealed lower risk of major amputation [RR = 0.23 (0.07; 0.80)] in NPWT-treated patients. The pooled results for healing rate and risk of any amputation were inconclusive due to large between-study heterogeneity. Overall, 6 deaths out of 158 patients were reported, none of them related to NPWT. Serious adverse events occurred in 6% of patients on NPWT.

CONCLUSIONS

This systematic review of observational studies provided supportive evidence that NWPT is an efficient and safe adjunct treatment in the management of DFUs.

Integra in Scalp Reconstruction After Tumor Excision: Recommendations From a Multidisciplinary Advisory Board

Integra is a dermal regeneration template used in the reconstruction of burns, traumatic injuries, or excision lesions in patients who present particular risk factors for traditional surgical procedures. A multidisciplinary advisory board of expert dermatologists and plastic surgeons have discussed the use of Integra in the reconstruction of scalp defects after tumor excision, focusing on the evidence derived from literature and on their experience in the treatment of approximately 400 patients. In this position paper, the authors summarize the main evidence discussed during the board, and the common practice guidelines proposed by the experts. The use of Integra is recommended in elderly patients with multiple comorbidities who have a higher risk for potential complications in traditional surgery; these patients may in fact benefit from a lower anesthetic risk, a less complicated postsurgical care and limited morbidity at the donor site obtained with the dermal template. Integra should also be used in the reconstruction of large and complex wounds and in case of bone exposure, as it helps to overcome the challenges related to wound healing in difficult areas. Notably, Integra has proven to be effective in patients who have undergone previous surgical procedures or adjuvant radiation therapy, in which previous incisions, scarring and radiation damages may hamper the effectiveness of traditional procedures. Finally, Integra is recommended in patients with recurrent and aggressive tumors who need closer tumor surveillance, as it gives easy access to the tumor site for oncologic follow-up examination.

Topical negative-pressure wound therapy: emerging devices and techniques

Introduction: The treatment of chronic wounds constitutes a massive financial burden to society and our health-care system. Therefore, efficient wound care is of great importance to all kinds of medical fields. The implementation and modification of negative-pressure wound therapy can be seen as a major improvement in wound healing. Many different NPWT applications evolved trying to address various wound etiologies.Areas covered: This review aims to give an overview of various NPWT applications, show its effects on wound healing, and discuss future modifications.Expert opinion: NPWT as a delivery device for cold plasma, growth factors, or targeted stem cells to the wound bed and the ability to monitor the inflammatory activity, bacterial load and wound healing factors can be seen as possible future steps to individualized wound care. In addition, it requires high-quality experimental studies to develop the ideal foam in terms of microstructure, pore size, and material properties.

Evaluating complications in below-knee skin cancer surgery after introduction of preoperative appointments: A 2-year retrospective cohort study

Below-knee dermatological surgery has a high risk of complications such as wound infection, bleeding, and necrosis. In this study, we evaluated the impact of preoperative appointments on complication risks. We searched the medical records of the Helsinki University Central Hospital (HUS) Dermatosurgery unit for all below-knee surgeries during 2016, when no preoperative nurse appointments were carried out, and compared it with 2018, when preoperative appointments for risk patients were introduced. The study included 187 patients in 2016 and 179 patients in 2018, of whom 68 (about one third) attended preoperative appointments. At the appointments, risk factors were evaluated, and compression therapy was introduced when possible. The results show complication rates of 13.4% in 2016 vs 10.1% in 2018 (P = .33), despite significantly higher risks in the 2018 patient group. The odds ratio for complications in appointment attendees vs non-attendees was reduced after adjustments to 0.58; however, this was insignificant (P = .47). The odds of complications for skin grafts were considerably higher: 11.33 vs other surgery techniques (P = .00). In conclusion, the introduction of preoperative appointments appeared to reduce complications in below-knee surgery. For graft reconstructions, complication risk is high, even with carefully planned pre- and postoperative care. Further studies are needed to evaluate preventable risk factors of below-knee graft reconstructions.

Effectiveness of Chronic Wound Debridement with the Use of Larvae of Lucilia Sericata

The process of successful wound healing depends on effective debridement and infection control. One method of wound debridement, known since antiquity, is based on the use of fly larvae. Solid scientific evidence proves that maggot debridement therapy (MDT), like surgical intervention, can be effectively and safely used to remove necrotic tissue. Based on a review of the related literature, this study was designed to assess the effectiveness of chronic wound cleansing with the use of larvae of Lucilia sericata (Phaenicia sericata). Maggot therapy, applied in wound debridement and treatment, is a safe and effective method. Its benefits are associated with debridement, disinfection and faster tissue growth. MDT may reduce the duration of antibiotic therapy and the need for hospitalization, or it may decrease the number of outpatient visits required. It is a relatively cost-effective method, and, in addition to financial gains, it may reduce the frequency of inpatient treatment. In the literature, an increasing amount of scientific evidence confirms that such treatment can effectively reduce the biofilm and bacterial load in a wound.

DNA methylation analysis of negative pressure therapy effect in diabetic foot ulcers

OBJECTIVE

Negative pressure wound therapy (NPWT) has been used to treat diabetic foot ulcerations (DFUs). Its action on the molecular level, however, is only partially understood. Some earlier data suggested NPWT may be mediated through modification of local gene expression. As methylation is a key epigenetic regulatory mechanism of gene expression, we assessed the effect of NPWT on its profile in patients with type 2 diabetes (T2DM) and neuropathic non-infected DFUs.

METHODS

Of 36 included patients, 23 were assigned to NPWT and 13 to standard therapy. Due to ethical concerns, the assignment was non-randomized and based on wound characteristics. Tissue samples were obtained before and 8 ± 1 days after therapy initiation. DNA methylation patterns were checked by Illumina Methylation EPIC kit.

RESULTS

In terms of clinical characteristics, the groups presented typical features of T2DM; however, the NPWT group had significantly greater wound area: 16.8 cm2 vs 1.4 cm2 (P = 0.0003). Initially only one region at chromosome 5 was differentially methylated. After treatment, 57 differentially methylated genes were found, mainly located on chromosomes 6 (chr6p21) and 20 (chr20p13); they were associated with DNA repair and autocrine signaling via retinoic acid receptor. We performed differential analyses pre treatment and post treatment. The analysis revealed 426 differentially methylated regions in the NPWT group, but none in the control group. The enrichment analysis showed 11 processes significantly associated with NPWT, of which 4 were linked with complement system activation. All but one were hypermethylated after NPWT.

CONCLUSION

The NPWT effect on DFUs may be mediated through epigenetic changes resulting in the inhibition of complement system activation.

Carrageenan hydrogel as a scaffold for skin-derived multipotent stromal cells delivery

Carrageenan is a thermoreversible polymer of natural origin widely used in food and pharmaceutical industry that presents a glycosaminoglycan-like structure. Herein, we show that kappa-type carrageenan extracted by a semi-refined process from the red seaweed Kappaphycus alvarezii displayed both chemical and structural properties similar to a commercial carrageenan. Moreover, both extracted carrageenan hydrogel and commercial carrageenan hydrogel can serve as a scaffold for in vitro culture of human skin-derived multipotent stromal cells, demonstrating considerable potential as cell-carrier materials for cell delivery in tissue engineering. Skin-derived multipotent stromal cells cultured inside the carrageenan hydrogels showed a round shape morphology and maintained their growth and viability for at least one week in culture. Next, the effect of the extracted carrageenan hydrogel loaded with human skin-derived multipotent stromal cells was evaluated in a mouse model of full-thickness skin wound. Macroscopic and histological analyses revealed some pointed ameliorated features, such as reduced inflammatory process, faster initial recovery of wounded area, and improved extracellular matrix deposition. These results indicate that extracted carrageenan hydrogel can serve as a scaffold for in vitro growth and maintenance of human SD-MSCs, being also able to act as a delivery system of cells to wounded skin. Thus, evaluation of the properties discussed in this study contribute to a further understanding and specificities of the potential use of carrageenan hydrogel as a delivery system for several applications, further to skin wound healing.