Evidence-based recommendations for negative pressure wound therapy: Treatment variables (pressure levels, wound filler and contact layer) – Steps towards an international consensus

Negative Pressure Level and Effects on Bacterial Growth Kinetics in an in vitro Wound Model

Negative Pressure Wound Therapy (NPWT) has been widely adopted in wound healing strategies due to its multimodal mechanism of action. While NPWT's positive impression on wound healing is well-established, its effect on bacterial load reduction remains equivocal. This study investigates NPWT's efficacy in reducing bioburden using an in vitro porcine skin model, focusing on the impact of Staphylococcus aureus and Staphylococcus epidermidis. Custom-made negative pressure chambers were employed to apply varying negative pressures. Porcine skin was cut into 5 × 5 cm squares and three standardized wounds of 6 mm each were created using a biopsy punch. Then, wounds were infected with S. aureus and S. epidermidis bacterial suspensions diluted 1:10,000 to obtain a final concentration of 1.5 × 104 CFU/ml and were placed in negative pressure chambers. After incubation, bacterial counts were expressed as colony-forming units (CFU) per ml. For S. aureus at 120 hours, the median CFU, mean area per colony, and total growth area were notably lower at -80 mmHg when compared to -250 mmHg and -50 mmHg, suggesting an optimal negative pressure for the pressure-dependent inhibition of the bacterial proliferation. While analyzing S. epidermidis at 120 hours, the response to the negative pressure was similar but less clear, with the minor CFU at -100 mmHg. The influence of intermittent negative pressure on the S. epidermidis growth showed notably lower median CFU with the interval therapy every hour compared to the S. aureus control group. This study contributes valuable insights into NPWT's influence on the bacterial load, emphasizing the need for further research to reformulate its role in managing contaminated wounds.

Updated Scenario on Negative Pressure Wound Therapy

Negative pressure wound therapy (NPWT) is a widely used and effective treatment for managing complex wounds. This document discusses how NPWT can be used in wound care in an updated way. The updated scenario on NPWT provides a concise overview of the current state of NPWT and its implications in clinical practice. It highlights recent developments in NPWT, as well as the advancements in this field. As part of NPWT, vacuum-assisted closure is used and negative pressure is applied to the wound bed. It discusses the key components and mechanisms. In addition to improving wound healing, NPWT also reduces infection rates and improves patient comfort, among other benefits. In addition, this document discusses the specific indications and contraindications of NPWT, as well as the types of wounds that can be treated with NPWT, including diabetic foot ulcers, pressure ulcers, and traumatic wounds. The document emphasizes the importance of choosing patients appropriately and assessing wounds to ensure optimal outcomes. In addition, it provides evidence-based guidelines and clinical recommendations on NPWT. In addition to reviewing the latest research findings supporting NPWT in a variety of clinical settings, it also discusses randomized controlled trials and systematic reviews. In addition, it discusses the potential complications and challenges associated with NPWT, including pain, bleeding, and device malfunction. The purpose of this document is to shed light on the role of NPWT in wound care management by providing an updated scenario. NPWT can be incorporated into clinical practice by healthcare professionals if they understand its principles, benefits, indications, and limitations. Healthcare providers can optimize patient outcomes and improve wound healing in diverse patient populations by staying abreast of the latest advancements in NPWT.

Polyurethane foam dressing with non-adherent membrane improves negative pressure wound therapy in pigs

OBJECTIVE

Negative pressure wound therapy (NPWT) is considered to be an effective technique to promote the healing of various wounds. The aim of this study was to evaluate different wound dressings combined with NPWT in treating wounds in Wuzhishan pigs.

METHOD

Excisions were made in the backs of the pigs and were covered with polyvinyl alcohol (PVA) dressing, polyurethane (PU) dressing or PU dressing with non-adherent membrane (PU-non-ad). NPWT was applied to the wound site. In the control group, basic occlusive dressing (gauze) without NPWT was applied. On days 0, 3, 7, 14, 21 and 28 post-surgery, the wound size was measured during dressing change, and wound healing rate (WHR) was calculated. In addition, blood perfusion within 2cm of the surrounding wound was measured by laser doppler flowmetry. Dressing specimen was collected and microbiology was analysed. Granulation tissues from the central part of the wounds were analysed for histology, vascular endothelial growth factor (VEGF) and cluster of differentiation 31 (CD31) mRNA expression.

RESULTS

The PU-non-ad-NPWT significantly (p<0.01) accelerated wound healing in the pigs. Further pathological analysis revealed that the non-adherent membrane effectively protected granulation tissue formation in PU-NPWT treated wounds. The blood perfusion analysis suggested that the non-adherent membrane improved the blood supply to the wound area. Microbiological analysis showed that non-adherent membrane decreased the bacterial load in the PU-NPWT dressing. VEGF and CD31 mRNA expression was upregulated in the wound tissue from the PU-non-ad-NPWT treated groups.

CONCLUSION

In this study, the PU dressing with non-adherent membrane was an ideal dressing in NPWT-assisted wound healing.

Effectiveness of Negative Pressure Wound Therapy During Aeromedical Evacuation Following Soft Tissue Injury and Infection

INTRODUCTION

Negative pressure wound therapy (NPWT) is utilized early after soft tissue injury to promote tissue granulation and wound contraction. Early post-injury transfers via aeromedical evacuation (AE) to definitive care centers may actually induce wound bacterial proliferation. However, the effectiveness of NPWT or instillation NPWT in limiting bacterial proliferation during post-injury AE has not been studied. We hypothesized that instillation NPWT during simulated AE would decrease bacterial colonization within simple and complex soft tissue wounds.

METHODS

The porcine models were anesthetized before any experiments. For the simple tissue wound model, two 4-cm dorsal wounds were created in 34.9 ± 0.6 kg pigs and were inoculated with Acinetobacter baumannii (AB) or Staphylococcus aureus 24 hours before a 4-hour simulated AE or ground control. During AE, animals were randomized to one of the five groups: wet-to-dry (WTD) dressing, NPWT, instillation NPWT with normal saline (NS-NPWT), instillation NPWT with Normosol-R® (NM-NPWT), and RX-4-NPWT with the RX-4 system. For the complex musculoskeletal wound, hind-limb wounds in the skin, subcutaneous tissue, peroneus tertius muscle, and tibia were created and inoculated with AB 24 hours before simulated AE with WTD or RX-4-NPWT dressings. Blood samples were collected at baseline, pre-flight, and 72 hours post-flight for inflammatory cytokines interleukin (IL)-1β, IL-6, IL-8 and tumor necrosis factor alpha. Wound biopsies were obtained at 24 hours and 72 hours post-flight, and the bacteria were quantified. Vital signs were measured continuously during simulated AE and at each wound reassessment.

RESULTS

No significant differences in hemodynamics or serum cytokines were noted between ground or simulated flight groups or over time in either wound model. Simulated AE alone did not affect bacterial proliferation compared to ground controls. The simple tissue wound arm demonstrated a significant decrease in Staphylococcus aureus and AB colony-forming units at 72 hours after simulated AE using RX-4-NPWT. NS-NPWT during AE more effectively prevented bacterial proliferation than the WTD dressing. There was no difference in colony-forming units among the various treatment groups at the ground level.

CONCLUSION

The hypoxic, hypobaric environment of AE did not independently affect the bacterial growth after simple tissue wound or complex musculoskeletal wound. RX-4-NPWT provided the most effective bacterial reduction following simulated AE, followed by NS-NPWT. Future research will be necessary to determine ideal instillation fluids, negative pressure settings, and dressing change frequency before and during AE.

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

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

Single-Use Negative Pressure Wound Therapy Applied on Various Wound Types: An Interventional Case Series

PURPOSE

The purpose of this study was to determine whether a single-use negative pressure wound therapy (NPWT) system achieves individualized goals of therapy when used to treat patients with a variety of wound types.

DESIGN

Multiple case series.

SUBJECTS AND SETTING

The same comprised 25 participants; their mean age was 51.2 years (SD: 18.2; range: 19-79 years); 14 were male (56%) and 11 were female (44%). Seven study participants withdrew from study participation. Wound etiologies vary; 4 had diabetic foot ulcers; 1 had a full-thickness pressure injury; 7 were treated for management of an abscess or cyst; 4 had necrotizing fasciitis, 5 had nonhealing postsurgical wounds, and 4 had wounds of other etiologies. Data were collected at 2 ambulatory wound care clinics located in the Southeastern United States (Augusta and Austell, Georgia).

METHODS

A single-outcome measure was selected for each participant by his or her attending physician at a baseline visit. Selected end points were (1) decrease in wound volume, (2) decrease in size of the tunneling area, (3) decrease in size of the undermining, (4) decrease in the amount of slough, (5) increase in granulation tissue formation, (6) decrease in periwound swelling, and (7) wound bed progression toward transition to another treatment modality (such as standard dressing, surgical closure, flap, or graft). Progress toward the individualized goal was monitored until the goal was achieved (study end point) or a maximum of 4 weeks following initiation of treatment.

RESULTS

The most common primary treatment goal was to achieve a decrease in wound volume (22 of 25 study participants), and the goal to increase granulation tissue was chosen for the remaining 3 study participants. A majority of participants (18 of 23, 78.3%) reached their individualized treatment outcome. The remaining 5 participants (21.7%) were withdrawn during the study (for reasons not related to the therapy). The median (interquartile range [IQR]) duration of NPWT therapy was 19 days (IQR: 14-21 days). Between baseline and the final assessment, median reductions in wound area and volume were 42.7% (IQR: 25.7-71.5) and 87.5% (IQR: 30.7-94.6).

CONCLUSIONS

The single-use NPWT system achieved multiple individualized treatment objectives in a variety of wound types. Individually selected goals of therapy were met by all study participants who completed the study.

Update on therapeutic strategy for esophageal anastomotic leak: A systematic literature review

Anastomotic leak is still a severe complication in esophageal surgery due to high mortality. This article reviews the updates on the treatment of anastomotic leak after esophagectomy in order to provide reference for clinical treatment and research. The relevant studies published in the Chinese Zhiwang, Wanfang, and MEDLINE databases to December 21, 2021 were retrieved, and esophageal carcinoma, esophagectomy, anastomotic leakage, and fistula selected as the keywords. A total of 78 studies were finally included. The treatments include traditional surgical drainage, new reverse drainage trans-fistula, stent plugging, endoscopic clamping, biological protein glue injection plugging, endoluminal vacuum therapy (EVT), and reoperation, etc. Early diagnosis, accurate classification and optimal treatment can promote the rapid healing of anastomotic leaks. EVT may be the most valuable approach, simultaneously with good commercial prospects. Reoperation should be considered in patients with complex fistula in which conservative treatment is insufficient or has failed.

Simplified vacuum dressing system: effectiveness and safety in wounds management

PURPOSE

Negative pressure wound therapy (NPWT) has revolutionized wound care, but its high cost reduces the procedure's availability. To solve the problem, streamlined vacuum dressings systems have been proposed, but the utility of these devices has been poorly studied. The objective of this study was to evaluate a simplified vacuum dressing system model (SVDM).

METHODS

Randomized clinical trial in which wounds were treated with SVDM compared to a complex occlusive dressing (silver hydrofiber, SHF). The analyzed outcomes were cleaning, presence of granulation tissue, clinical appearance, and indication for surgical closure of wounds.

RESULTS

Fifty injuries were treated (25 in each group), most located on lower limbs. SVDM proved to be more effective than SHF in the evaluated outcomes. Wound recalcitrance reduced the effectiveness of the equipment used. Despite its efficacy, complications occurred, the most frequent related to dressing changes: minor bleeding, foam adherence to a wound bed, and pain. Only for bleeding no favorable risk-benefit ratio was found. There were no severe complications, worsening conditions of injuries, or deaths.

CONCLUSIONS

SVDM proved to be an effective and acceptably safe device for managing studied wounds.

Efficacy of Prophylactic Negative-Pressure Wound Therapy with Delayed Primary Closure for Contaminated Abdominal Wounds

Background. Prophylactic negative-pressure wound therapy (NPWT) to prevent surgical site infection (SSI) may be effective for severely contaminated wounds. We investigated the safety and efficacy of NPWT with delayed primary closure (DPC) for preventing SSI. Methods. For patients with contaminated and dirty/infected surgical wounds after an emergency laparotomy, the abdominal fascia was closed with antibacterial absorbent threads and the skin was left open. Negative pressure (−80 mmHg) was applied through the polyurethane foam, which was replaced on postoperative days 3 and 7. DPC was performed when sufficient granulation was observed. The duration and adverse events of NPWT, the development of SSI, and the postoperative hospital stay were retrospectively reviewed. Results. We analyzed the cases of patients with contaminated (n = 15) and dirty/infected wounds (n = 7). The median duration of NPWT was 7 days (range 5–11 days). NPWT was discontinued in one (4.5%) patient due to wound traction pain. SSI developed in seven patients (31.8%), with incisional SSI in one (4.5%) and organ/space SSI in six (27.3%). The median postoperative hospital stay was 17 days (range 7–91 days). There was no significant relationship between postoperative hospital stay and wound classification ( $P=0.17$ ) or type of SSI ( $P=0.07$ ). Conclusion. Prophylactic NPWT with DPC was feasible and may be particularly suitable for severely contaminated wounds, with a low incidence of incisional SSI.

Characteristics and Safety Profiles of a Hydrocolloid Polyester Dressing Incorporated with Herbal Extract: In Vitro, in Vivo and Randomized Clinical Studies

The polyester dressing containing herbal extract had been used for several years. However, some properties had not been investigated. This study examined three parts including in vitro studies, skin irritation in an animal model, and the pilot clinical study in traumatic wounds. In in vitro studies, six different wound dressings consisted of hydrocolloid polyester containing herbal extract (SI-HERB®), hydrofiber (Aquacel®), hydrocolloid polyester (Urgotul®), soft paraffin gauze (Bactigras®), foam (Mepilex®), and biocellulose (Suprasorb® X + PHMB) dressings were comparatively evaluated in physical properties including the fluid absorption, desorption, and fluid drainage ability. The skin irritation test was examined in a rabbit model using SI-HERB® as a tested group. In a clinical study, traumatic patients with leg wounds were randomly assigned to six wound dressings. The primary outcome was the pain level and the secondary outcomes were non-adherence and peri-wound reaction evaluating score. From the study, Bactigras® had the largest pore size but the total area of pore size per field of it was similar to SI-HERB®. There were no significant differences between SI-HERB®, Urgotul®, and Bactigras® in the percentage of absorption and desorption. No dermatologic effect was found in the animal study. In the irritation test on leg wounds, pain level, and peri-wound reaction in hydrocolloid polyester dressing group were significantly lower compared with Aquacel® and Bactigras®. The polyester dressing had the pain level after removal lower than before application while the Mepilex® and Suprasorb® presented that insignificantly increase the pain level. Erythema could be observed in Bactigras®, Aquacel®, and Suprasorb® but the edema scores were not different. A hydrocolloid polyester dressing containing herbal extract had good drainage ability. No skin irritation was reported. Pain scores, removal ability, and peri-wound reaction were also significantly lower with other types of wound dressings. These results suggested that this dressing be an alternative in wound treatment.

Can Prophylactic Incisional Negative Pressure Wound Therapy reduce Wound Complications after Inguinal Lymph Node Dissection for Melanoma? Results from a Randomized Controlled Trial

Background

Methods

Results

Conclusion

Trial registration

A programmable and skin temperature-activated electromechanical synergistic dressing for effective wound healing

Mechanical regulation and electric stimulation hold great promise in skin tissue engineering for manipulating wound healing. However, the complexity of equipment operation and stimulation implementation remains an ongoing challenge in clinical applications. Here, we propose a programmable and skin temperature-activated electromechanical synergistic wound dressing composed of a shape memory alloy-based mechanical metamaterial for wound contraction and an antibacterial electret thin film for electric field generation. This strategy is successfully demonstrated on rats to achieve effective wound healing in as short as 4 and 8 days for linear and circular wounds, respectively, with a statistically significant over 50% improvement in wound closure rate versus the blank control group. The optimally designed electromechanical synergistic stimulation could regulate the wound microenvironment to accelerate healing metabolism, promote wound closure, and inhibit infection. This work provided an effective wound healing strategy in the context of a programmable temperature-responsive, battery-free electromechanical synergistic biomedical device.

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.

Use of autologous conditioned serum dressings in hard-to-heal wounds: a randomised prospective clinical trial

OBJECTIVE

In this study, we aimed to assess both the efficacy and tolerability of autologous conditioned serum (ACS) as an innovative wound dressing in the local management of hard-to-heal wounds.

METHOD

In this single-blinded randomised controlled trial, patients with hard-to-heal wounds were randomly assigned to receive either ACS treatment or normal saline (NS) dressings. The treatment was applied once a week for three weeks with a final assessment at three weeks from the first ACS application.

RESULTS

A total of 30 patients took part in the study. Analysis of wound assessment data demonstrated statistically significant differences for wound surface area and Pressure Ulcer Scale for Healing scores (area score, exudate and tissue) from baseline to the end of the study in patients who received the ACS dressing, but not in patients who received the normal saline dressing. There were statistically significant differences in changes in: the wound surface area at week three (-6.4±2.69cm² versus +0.4±2.52cm²); area score at week three (-2.2±1.08 versus +0.2±0.86); exudate at week two (-1.2±0.70 versus +0.0±0.45) and at week 3 (-1.3±0.72 versus -0.1±0.63); tissue at week two (-1.1±0.35 versus +0.0±0.53) and at week three (-1.8±0.65 versus -0.1±0.63); and the PUSH total score at week one (-1.6±0.98 versus +0.4±1.22), week two (-3.2±0.86 versus +0.4±0.98) and week three (-5.3±1.17 versus -0.0±1.33) between the ACS and NS groups, respectively.

CONCLUSION

This trial revealed a significant decrease in wound surface area as well as a considerable improvement in wound healing in the ACS dressing group.

The Role of Negative-Pressure Wound Therapy in Patients with Fracture-Related Infection: A Systematic Review and Critical Appraisal

INTRODUCTION

Fracture-related infection (FRI) is a severe musculoskeletal complication in orthopedic trauma surgery, causing challenges in bony and soft tissue management. Currently, negative-pressure wound therapy (NPWT) is often used as temporary coverage for traumatic and surgical wounds, also in cases of FRI. However, controversy exists about the impact of NPWT on the outcome in FRI, specifically on infection recurrence. Therefore, this systematic review qualitatively assesses the literature on the role of NPWT in the management of FRI.

METHODS

A literature search of the PubMed, Embase, and Web of Science database was performed. Studies that reported on infection recurrence related to FRI management combined with NPWT were eligible for inclusion. Quality assessment was done using the PRISMA statement and the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

After screening and quality assessment of 775 unique identified records, eight articles could be included for qualitative synthesis. All eight studies reported on infection recurrence, which ranged from 2.8% to 34.9%. Six studies described wound healing time, varying from two to seven weeks. Four studies took repeated microbial swabs during subsequent vacuum dressing changes. One study reported newly detected pathogens in 23% of the included patients, and three studies did not find new pathogens.

CONCLUSION

This review provides an assessment of current literature on the role of NPWT in the management of soft tissue defects in patients with FRI. Due to the lack of uniformity in included studies, conclusions should be drawn with caution. Currently, there is no clear scientific evidence to support the use of NPWT as definitive treatment in FRI. At this stage, we can only recommend early soft tissue coverage (within days) with a local or free flap. NPWT may be safe for a few days as temporarily soft tissue coverage until definitive soft tissue management could be performed. However, comparative studies between NPWT and early wound closure in FRI patients are needed.

A prospective, randomized, controlled clinical study on the effectiveness of a single-use negative pressure wound therapy system, compared to traditional negative pressure wound therapy in the treatment of diabetic ulcers of the lower extremities

A multicenter, phase 4, randomized, comparative-efficacy study in subjects with lower extremity wounds was carried out to compare wound closure rates, for a single-use negative pressure wound therapy (s-NPWT) versus traditional NPWT (t-NPWT) systems over a 12-week treatment period. From the initial population of patients with diabetic foot ulcers (DFU) and venous leg ulcers (VLU), we analyzed a subgroup of patients with diabetes mellitus and leg and foot ulcers (either DFUs or VLUs in diabetics), termed, the diabetic lower extremity ulcers (DLEU). In the DLEU group, there were 95 patients in intention-to-treat (ITT) and 61 patients in per protocol (PP) populations, respectively. We found a significant difference in favor of s-NPWT over t-NPWT in the confirmed wound closures at 12 weeks both in ITT (p < 0.001) and PP populations (p = 0.017). Significantly higher wound closure rates in s-NPWT group suggest that s-NPWT should be preferred NPWT option for DLEU.

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.

A retrospective cohort study comparing clinical outcomes and healthcare resource utilisation in patients undergoing surgery for osteomyelitis in England: a case for reorganising orthopaedic infection services

Aims: An investigation of the impact of a multidisciplinary bone infection unit (BIU) undertaking osteomyelitis surgery with a single-stage protocol on clinical outcomes and healthcare utilisation compared to national outcomes in England. Patients and Methods: A tertiary referral multidisciplinary BIU was compared to the rest of England (ROE) and a subset of the 10 next busiest centres based on osteomyelitis treatment episode volume (Top Ten), using the Hospital Episodes Statistics database (HES). A total of 25 006 patients undergoing osteomyelitis surgery between April 2013 and March 2017 were included. Data on secondary healthcare resource utilisation and clinical indicators were extracted for 24 months before and after surgery. Results: Patients treated at the BIU had higher orthopaedic healthcare utilisation in the 2 years prior to their index procedure, with more admissions (p< 0.001) and a mean length of stay (LOS) over 4 times longer than other groups (10.99 d, compared to 2.79 d for Top Ten and 2.46 d for the ROE, p< 0.001). During the index inpatient period, the BIU had fewer mean theatre visits (1.25) compared to the TT (1.98, p< 0.001) and the ROE (1.64, p= 0.001). The index inpatient period was shorter in the BIU (11.84 d), 33.6 % less than the Top Ten (17.83 d, p< 0.001) and 29.9 % shorter than the ROE (16.88 d, p< 0.001). During follow-up, BIU patients underwent fewer osteomyelitis-related reoperations than Top Ten centres (p= 0.0139) and the ROE (p= 0.0137). Mortality was lower (4.71 %) compared to the Top Ten (20.06 %, p< 0.001) and the ROE (22.63 %, p< 0.001). The cumulative BIU total amputation rate was lower (6.47 %) compared to the Top Ten (15.96 %, p< 0.001) and the ROE (12.71 %, p< 0.001). Overall healthcare utilisation was lower in the BIU for all inpatient admissions, LOS, and Accident and Emergency (A&E) attendances. Conclusion: The benefits of managing osteomyelitis in a multi-disciplinary team (MDT) specialist setting included reduced hospital stays, lower reoperation rates for infection recurrence, improved survival, lower amputation rates, and lower overall healthcare utilisation. These results support the establishment of centrally funded multidisciplinary bone infection units that will improve patient outcomes and reduce healthcare utilisation.

NPWTi allows safe delayed free flap repair of Gustilo IIIb injuries: A prospective case series

Introduction

Free flap lower extremity repair is associated with a high complication rate (>31%); higher rates are observed in more severe patients. In cases requiring prior systemic/local stabilization, delayed repair increases complication rate (+10% at 7 days): Negative-pressure Wound Therapy (NPWT) decreases complications but only when applied for less than 7 days. Recent limited evidence suggests that augmentation of NPWT with instillation for wound irrigation (NPWTi) might safely extend such window. This study hypothesizes that, through the combined cleansing effect of NPWT and instillation, NPWTi allows safe (low complication rate) delayed free flap repair in severe patients with Gustilo IIIb injuries (GIIIb).

Methods

A prospective case series was designed (inclusion criteria: GIIIb requiring microsurgical repair, severe patient/injury condition preventing immediate/early repair; exclusion criteria: allergy to NPWTi dressing). Patients received NPWTi (suction: 125 mmHg continuous; irrigation: NaCl 0.9%) until considered clinically ready for repair. Preoperative/postoperative complications (dehiscence, wound infection, bone non-union, osteomyelitis, flap failure) were monitored with clinical signs, imaging, and serum markers (CRP, WBC).

Results

Four patients (male: N = 4, female N = 1; Age: 59 [44-75] years-old) were treated. NPWTi was applied for 15.2 [9-28] days. No complication (0%) was observed preoperatively or postoperatively. Delayed repair occurred by latissimus dorsi musculocutaneous flap (N = 3), and anterolateral thigh flap (N = 2). All patients walked weight-bearing 12 [6-20] weeks after injury.

Conclusions

NPWTi seems to allow safe delayed free flap repair in patients with severe lower extremity injuries unable to undergo immediate/early repair.

The role of negative pressure wound therapy (NPWT) on the treatment of pyoderma gangrenosum: A systematic review and personal experience

Pyoderma gangrenosum (PG) is a rare painful ulcerative neutrophilic inflammatory skin disease, necessitating a high level of diagnostic suspicion associated with appropriate treatment to avoid progression. Negative pressure wound therapy (NPWT) has been efficiently used in the treatment of different types of wounds. However, the role of NPWT in the management of PG is still controversial, due to the risk of the pathergy phenomenon. In this article, we conducted a systematic review (according to the PRISMA guidelines) on the use of NPWT in the treatment of PG, and we report our personal experience with two patients treated with this device. The result of the review showed that articles on the topic are, in their entirety, of low levels of evidence, such as case series, case reports, and reviews. Improvement in wound healing with the use of NPWT was observed in 85.1% of the patients studied. Besides, a significant association between improvement in wound healing with NPWT and immunosuppressive therapy was observed. Regarding the cases reported here, both showed good outcomes with the use of NPWT and skin graft during the treatment of PG injuries. Due to the rarity of PG, there is a scarcity of studies with robust evidence for standardization and comparison between treatments, which consequently makes it difficult to select therapeutic options. However, based on this systematic review and reported cases, we consider NPWT a safe option for adjuvant treatment of wounds caused by PG if combined with systemic immunosuppression, which plays a key role in greater chances of successful treatment. This approach should be recommended, whenever possible, associated with skin grafting to accelerate wound closure. The role of negative pressure wound therapy (NPWT) on the treatment of pyoderma gangrenosum: a systematic review and personal experience.

Pilonidal Cyst Excision: Primary Midline Closure with versus without Closed Incision Negative Pressure Therapy

Background

Pilonidal cysts are a painful condition that primarily affect young adult men. In the literature, numerous operative techniques for resolving pilonidal cysts are described, with variable outcomes. The objective of this study was to compare primarily closed midline incisions managed with or without the use of closed incision negative pressure therapy after pilonidal cyst excision.

Methods

Twenty-one patients underwent excision and midline primary closure. Postoperative care composed of closed incisional negative pressure therapy (study group; n = 10) or gauze dressings (control group; n = 11). In both groups, the sutures were partially removed on day 14 and completely removed on day 21. Compared outcomes included the duration of hospitalization, pain on the day of surgical procedure, and on postoperative day 7, and time-to-healing.

Results

The median hospital stay was about 9 hours and 23 hours in the study and control groups, respectively (P < 0.05). The median pain scores on the day of operation were 1.20/10 in the study group and 3.36/10 in the control group (P < 0.05). On day 7, study group showed median pain score 0.9/10 and control group showed 2.63/10 (P < 0.05). The mean healing time was 23.8 and 57.9 days in the ciNPT group and gauze group, respectively (P < 0.05).

Conclusion

These outcomes supported the incorporation of closed incision negative pressure therapy into our surgical treatment protocol for pilonidal cysts.

Effect of Negative Pressure Wound Therapy in Electrical Burns

Electrical burns are capable of damaging cells through both thermal and nonthermal mechanisms. The complexity of these wounds, the deterioration in time, and the conversion during the first days make managing them a challenge. Negative pressure wound therapy (NPWT) is a technology that can be used as a tool to improve outcomes in patients with burns in the acute and reconstructive phases of the treatment. We describe 2 cases in which we apply this technology in electrical injuries. We present 2 cases of patients with electrical burns who underwent NPWT with instillation (NPWTi) with saline solution in the acute phase, to block the conversion of the burn and to improve the granulation tissue and in the reconstructive phase, as a tool to improve the grafts take. Both patients showed early formation of granulation tissue adequate for surgical reconstruction, and neither of them presented loss of skin grafts. In the acute phase, NPWT with instillation when applied in these patients showed fast formation of granulation tissue adequate for early reconstruction, whereas NPWT in the reconstructive phase when applied to bolster grafts showed improvements in grafts take. NPWT is a useful tool to support the surgical management of the electrical injuries during the acute phase to prepare the wound for early reconstruction and after the skin grafts reconstruction to improve the grafts take.

Transrectal endoscopic drainage with vacuum-assisted therapy in patients with anastomotic leaks following rectal cancer resection

Background

Surgery is the gold standard for the treatment of malignant tumors of the rectum. Intestinal anastomotic leakage remains a serious complication of colorectal surgery. The efficacy and safety of transrectal endoscopic drainage by vacuum therapy in patients with intestinal anastomotic leakage after surgical treatment of middle and distal rectal tumors were assessed.

Methods

Prospective analysis of treatment outcomes among patients undergoing surgery for middle and distal rectal tumors at the Department of General, Gastroenterological, and Oncological Surgery of the Ludwik Rydygier Collegium Medicum in Bydgoszcz and Nicolaus Copernicus University in Torun from 2016 to 2019 was conducted.

Results

Seventy-nine patients with middle and distal rectal tumors underwent laparoscopic resection. Intestinal anastomotic leak was identified in 18 (22.79%) patients [all men, mean age 61.39 (43–86) years] during the postoperative period. Primary protective ileostomy was performed in 8/18 (44.44%) patients. All 18 patients were treated with endoluminal vacuum therapy via transrectal endoscopic drainage. The mean time from surgery to the diagnosis of leakage and initiation of endoscopic treatment was 16 (3–728) days. The mean number of endoscopic procedures per patient was 6 (1–11). The mean duration of endoscopic treatment was 22 (4–43) days. Complications of endotherapy occurred in 2/18 (11.11%) patients treated endoscopically for bleeding from the abscess cavity. Success of endoluminal vacuum therapy was achieved in 17/18 (94.44%) patients. Moreover, 5/18 (27.78%) patients required ileostomy during the endoscopic treatment. The mean follow-up period was 368 (118–724) days. Long-term success of transrectal endoscopic drainage using vacuum-assisted therapy was achieved in 15/18 (83.33%) patients.

Conclusions

Endoscopic rectal drainage using vacuum-assisted therapy is an effective and safe minimally invasive treatment in patients with intestinal anastomotic leaks following resection procedures within the middle and distal rectum.

Multidisciplinary approach for large retroperitoneal abscess management: A case report

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Retroperitoneal abscess is a rare disease entity that lack of specific clinical manifestations and often misdiagnosis.

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Multi-disciplinary approach is needed for manage severe retroperitoneal abscess.

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The usage of negative wound pressure therapy and honey-impregnated gauze for wound bed preparation.

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The utilization of lumbar artery perforator (LAP) Flap for large defect closure in retroperitoneal region.

Introduction and importance

Retroperitoneal abscess is a rare disease that is often difficult to diagnose and require multidisciplinary management. We report a case of large retroperitoneal abscess and the usage lumbar artery perforator (LAP) for the defect closure.

Case presentation

A 52-year-old-women was admitted to our emergency with a chief complaint of left flank pain. Patient had history of multiple genitourinary tract procedure and diabetes mellitus type 2. We found a bulging mass on the left flank accompanied by pressure pain. A contrast CT scan revealed a large abscess on the retroperitoneal region that involved the left retroperitoneal hemiabdomen muscles. We performed multistage-treatment comprising of radical abscess debridement, followed by honey-impregnated gauze and negative pressure wound therapy for wound bed preparation. Post-debridement, the defect was closed with LAP and keystone flap. LAP flap was raised and transposed to close the defect on the caudal area. One-month follow up showed the outcome was satisfactory.

Clinical discussion

In our case, the source of infection was thought to origin from genitourinary infection. The history of multiple urology procedures and diabetes mellitus became the main risk factors. Multistage managements were needed to eradicate the abscess. The usage of NPWT and honey-impregnated gauze was proven successful in preparing the wound bed prior to definitive closure. Lastly, the utilization LAP flap combined with keystone flap showed satisfactory outcome for defect closure.

Conclusion

The management of patient with large retroperitoneal abscess require multidisciplinary approach including extensive debridement and well-prepared wound bed. In this report, LAP flap was proven reliable option to resurface large defect around flank area.

Negative pressure wound therapy does not diminish efficacy of topical antibiotic powder in a preclinical contaminated wound model

AIMS

High-energy injuries can result in multiple complications, the most prevalent being infection. Vancomycin powder has been used with increasing frequency in orthopaedic trauma given its success in reducing infection following spine surgery. Additionally, large, traumatic injuries require wound coverage and management by dressings such as negative pressure wound therapy (NPWT). NPWT has been shown to decrease the ability of antibiotic cement beads to reduce infection, but its effect on antibiotic powder is not known. The goal of this study was to determine if NPWT reduces the efficacy of topically applied antibiotic powder.

METHODS

Complex musculoskeletal wounds were created in goats and inoculated with a strain of Staphylococcus aureus modified to emit light. Six hours after contaminating the wounds, imaging, irrigation, and debridement and treatment application were performed. Animals received either vancomycin powder with a wound pouch dressing or vancomycin powder with NPWT.

RESULTS

There were no differences in eradication of bacteria when vancomycin powder was used in combination with NPWT (4.5% of baseline) compared to vancomycin powder with a wound pouch dressing (1.7% of baseline) (p = 0.986), even though approximately 50% of the vancomycin was recovered in the NPWT exudate canister.

CONCLUSION

The antimicrobial efficacy of the vancomycin powder was not diminished by the application of NPWT. These topical and locally applied therapies are potentially effective tools that can provide quick, simple treatments to prevent infection while providing coverage. By reducing the occurrence of infection, the recovery is shortened, leading to an overall improvement in quality of life. Cite this article: Bone Joint Res 2021;10(2):149-155.

Necrotizing soft tissue infection after liposculpture; Case report

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Infections in isolated liposuction procedures are reported as only 0.1 % of cases

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One of the most serious complications of liposuction is necrotizing soft tissue infection (NSTI).

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Rapid recognition of NSTI is life saving; with urgent extensive debridement and prophylactic antibiotics as the mainstay of treatment for this condition

Introduction

Liposculpture procedures have a complication rate of 5%, with the majority being minor complications. Infections in isolated liposuction procedures are as low as 0.1 % of cases. Necrotizing infections can occur after major traumatic injuries, as well as after minor breaches of the skin or mucosa. Here we present a case of a 53-year-old female patient who underwent cosmetic surgery and developed a necrotizing soft tissue infection and we will discuss the importance of early diagnosis, risk factors and preventive measures, treatment options and our management of this particular case.

Presentation of Case

53-year-old female patient with a history of multiple cosmetic surgeries, with no significant past medical history, she presented fever and disabling pain at the surgical site with extensive bullae formation; during her fourth post operative day, she presented septic shock that required vasopressor support and mechanical ventilation, accompanied by acute renal failure which required admission to the intensive care unit.

The patient’s relatives requested air transportation to bring the patient to our center.

The patient remained hospitalized for 42 days in which 15 surgical interventions were performed including multiple surgical wound cleansing and debridement as well as placement of a negative pressure wound therapy system, flaps advancement, lesions reconstruction, graft procurements and insertions.

Discussion

Antibiotic prophylaxis is recommended preferably with a second-generation cephalosporin, one hour prior to surgery and should be continued for 5–6 days afterwards. Likewise, prophylaxis with Flucloxacillin or gentamicin is recommended in the case of liposuction and or abdominoplasty. The microorganisms most frequently isolated in post-liposuction infections are Staphylococcus aureus, Streptococcus group A, Streptococcous pyogenes, and synergistic infections with anaerobes and facultative pathogens.

Among the most severe complications of liposuction is necrotizing soft tissue infection (NSTI), which is an infection of the subcutaneous tissue that spreads to the underlying dermis and sometimes beyond including the fascia and muscle.

Conclusion

Rapid recognition of NSTI is life-saving and urgent, extensive debridement and prophylactic antibiotics are the mainstay treatment for this condition, multiple debridement procedures may be necessary for successful treatment.

Pediatric necrotizing soft tissue infection after elective surgery: A case report and literature review

INTRODUCTION

Necrotizing soft tissue infections (NSTIs) are rare but often lethal. Early diagnosis and aggressive surgical debridement are essential to achieve the best possible outcome.

CASE PRESENTATION

A 12-year old boy was diagnosed with a necrotizing soft tissue infection following elective revision surgery for functional impairment resulting from scar tissue of the neck. Fever and inflammation of the surgical wound manifested 24-36 hours postoperatively. Antibiotic therapy with amoxicillin-clavulanic acid was initiated, but the patient was unresponsive. Ultrasonography, a wound culture and surgical exploration confirmed the diagnosis. The culture was positive for a Streptococcus pyogenes infection and antibiotic treatment was switched to penicillin and clindamycin. Following the diagnosis, surgical debridement was performed subcutaneously, and only necrotic tissue was removed to preserve as much skin tissue as possible. After eradication of the infection, vacuum-assisted closure of the wound was used to close the subcutaneous space. The patient was discharged after 40 days.

CONCLUSION

In this patient, we treated a necrotizing soft tissue infection with antibiotics, skin sparing surgeries and negative pressure wound therapy (NPWT). We used ultrasonography as imaging technique to help with the diagnosis. The extensiveness of surgical debridement was rather limited. We focused on opening all affected fascial layers. The surgical debridement was subcutaneous, and only necrotic tissue was removed. Because of the location in the neck, we tried to avoid an aggressive skin debridement to preserve as much skin tissue as possible. Negative pressure wound therapy is not frequently used in this context but it contributed to an enhanced wound healing. Ultrasonography for diagnosing NSTIs is useful, but the clinical findings and an explorative surgery will remain most important.

Terapia de presión negativa en pediatría

Introducción. La terapia de presión negativa es un recurso utilizado cada vez con mayor frecuencia en el manejo de heridas complejas en pediatría. El objetivo de este estudio fue describir la experiencia con esta terapia en diferentes situaciones clínicas. Métodos. Se llevó a cabo un estudio descriptivo retrospectivo en un grupo de pacientes pediátricos en quienes se utilizó la terapia de presión negativa entre el año 2010 y el 2015. Se analizaron las variables sociodemográficas, los diagnósticos que indicaron la terapia, el tiempo de uso, sus complicaciones y la mortalidad. Resultados. Se incluyeron 41 pacientes. La terapia se indicó en 39 casos con heridas localizadas en el abdomen, en uno con infección de los tejidos blandos perianales y en otro con una herida de esternotomía infectada. De las heridas abdominales, 14 fueron por complicaciones relacionadas con apendicitis aguda, 6 por enfermedades relacionadas con megacolon, 5 por obstrucción intestinal, 4 para el manejo de fístulas, 4 por enterocolitis necrosante del recién nacido, 3 por pancreatitis aguda y 3 por otras causas. El tiempo promedio de uso de la terapia fue de 7 días. Se presentaron fallas en el sistema de vacío en dos pacientes, pero no hubo complicaciones por el uso de la terapia. Dos pacientes fallecieron por complicaciones relacionadas con su enfermedad de base. Conclusión. La terapia de presión negativa es un recurso efectivo en el manejo de heridas complejas en la población pediátrica.

Use of negative pressure wound therapy to treat a cochlear implant infection around the auricle: a case report

Although negative pressure wound therapy (NPWT) is widely used, its application to the head and neck region remains challenging due to anatomical complexities. This report presents the case of a female patient presenting with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes, uncontrolled diabetes and severe bilateral sensorineural hearing loss. The patient had undergone cochlear implant surgery and five months later the wound was infected with methicillin-resistant Staphylococcus aureus (MRSA). NPWT was started shortly after removing the internal receiver and was stopped 11 days later. NPWT helped in controlling infection and led to a successful wound closure. In this case, NPWT was effective in treating infectious wounds around the auricle after cochlear implant surgery. Declaration of interest: The authors have no financial support for this article and no conflict of interest directly relevant to the content of this article.

A Prospective Randomized Study: The Usefulness and Efficacy of Negative Pressure Wound Therapy with Lipidocolloid Polyester Mesh Compared to Traditional Negative Pressure Wound Therapy for Treatment of Pressure Ulcers

To improve healing of pressure ulcer wounds, it is important to optimize the conditions of the area surrounding the wound. Negative pressure wound therapy (NPWT) promotes wound healing, however, the removal of NPWT can cause pain or focal bleeding, delaying wound healing or causing infection. In this study, we reviewed the efficacy of the lipidocolloid non-adherent dressing (Urgotul^®) as a wound contact layer. A total of 38 patients from the same facility who applied NPWT from April 2016 to October 2019 were included and divided into two groups; NPWT with the lipidocolloid non-adherent dressing (group 1, experimental group, 19 patients) and NPWT only (group 2, control group, 19 patients). The condition of the wound was examined prior to NPWT application, at one week, and again at three weeks after application. No significant differences were found between groups for general characteristics, bacterial culture or photo analysis. However, when comparing groups based on the time of examination, there was a significant reduction of the wound size in group 1 (p = 0.001) but not in group 2 (p = 0.082). Therefore, the current study finds that using the lipidocolloid non-adherent dressing as a wound contact layer in NPWT stimulates healing by shrinking the size of the pressure ulcer wound.

EWMA Document: Negative Pressure Wound Therapy

1. Introduction Since its introduction in clinical practice in the early 1990's negative pressure wounds therapy (NPWT) has become widely used in the management of complex wounds in both inpatient and outpatient care.¹ NPWT has been described as a effective treatment for wounds of many different aetiologies^2,3 and suggested as a gold standard for treatment of wounds such as open abdominal wounds,^4-6 dehisced sternal wounds following cardiac surgery^7,8 and as a valuable agent in complex non-healing wounds.^9,10 Increasingly, NPWT is being applied in the primary and home-care setting, where it is described as having the potential to improve the efficacy of wound management and help reduce the reliance on hospital-based care.¹¹ While the potential of NPWT is promising and the clinical use of the treatment is widespread, highlevel evidence of its effectiveness and economic benefits remain sparse.^12-14 The ongoing controversy regarding high-level evidence in wound care in general is well known. There is a consensus that clinical practice should be evidence-based, which can be difficult to achieve due to confusion about the value of the various approaches to wound management; however, we have to rely on the best available evidence. The need to review wound strategies and treatments in order to reduce the burden of care in an efficient way is urgent. If patients at risk of delayed wound healing are identified earlier and aggressive interventions are taken before the wound deteriorates and complications occur, both patient morbidity and health-care costs can be significantly reduced. There is further a fundamental confusion over the best way to evaluate the effectiveness of interventions in this complex patient population. This is illustrated by reviews of the value of various treatment strategies for non-healing wounds, which have highlighted methodological inconsistencies in primary research. This situation is confounded by differences in the advice given by regulatory and reimbursement bodies in various countries regarding both study design and the ways in which results are interpreted. In response to this confusion, the European Wound Management Association (EWMA) has been publishing a number of interdisciplinary documents^15-19 with the intention of highlighting: The nature and extent of the problem for wound management: from the clinical perspective as well as that of care givers and the patients Evidence-based practice as an integration of clinical expertise with the best available clinical evidence from systematic research The nature and extent of the problem for wound management: from the policy maker and healthcare system perspectives The controversy regarding the value of various approaches to wound management and care is illustrated by the case of NPWT, synonymous with topical negative pressure or vacuum therapy and cited as branded VAC (vacuum-assisted closure) therapy. This is a mode of therapy used to encourage wound healing. It is used as a primary treatment of chronic wounds, in complex acute wounds and as an adjunct for temporary closure and wound bed preparation preceding surgical procedures such as skin grafts and flap surgery. Aim An increasing number of papers on the effect of NPWT are being published. However, due to the low evidence level the treatment remains controversial from the policy maker and health-care system's points of view-particularly with regard to evidence-based medicine. In response EWMA has established an interdisciplinary working group to describe the present knowledge with regard to NPWT and provide overview of its implications for organisation of care, documentation, communication, patient safety, and health economic aspects. These goals will be achieved by the following: Present the rational and scientific support for each delivered statement Uncover controversies and issues related to the use of NPWT in wound management Implications of implementing NPWT as a treatment strategy in the health-care system Provide information and offer perspectives of NPWT from the viewpoints of health-care staff, policy makers, politicians, industry, patients and hospital administrators who are indirectly or directly involved in wound management.

A prospective, randomized, controlled clinical trial on the efficacy of a single-use negative pressure wound therapy system, compared to traditional negative pressure wound therapy in the treatment of chronic ulcers of the lower extremities

Multicenter, phase‐4, randomized, comparative‐efficacy study in patients with VLUs or DFUs comparing for noninferiority the percentage change in target ulcer dimensions (area, depth, and volume) a single‐use negative pressure wound therapy (s‐NPWT) system versus traditional NPWT (t‐NPWT) over a 12‐week treatment period or up to confirmed healing. Baseline values were taken at the randomization visit. Randomized by wound type and size, 164 patients with non‐infected DFUs and VLUs were included. The ITT population was composed of 161 patients (101 with VLUs, 60 with DFUs) and 115 patients completed follow‐up (64 in the s‐NPWT group and 51 in the t‐NPWT group) (PP population). The average age for all patients was 61.5 years, 36.6% were women, and treatment groups were statistically similar at baseline. Primary endpoint analyses on wound area reduction demonstrated statistically significant reduction in favor of s‐NPWT (p = 0.003) for the PP population and for the ITT population (p < 0.001). Changes in wound depth (p = 0.018) and volume (p = 0.013) were also better with s‐NPWT. Faster wound closure was observed with s‐NPWT (Cox Proportional Hazards ratio (0.493 (0.273, 0.891); p = 0.019) in the ITT population. Wound closure occurred in 45% of patients in the s‐NPWT group vs. 22.2% of patients in the t‐NPWT group (p = 0.002). Median estimate of the time to wound closure was 77 days for s‐NPWT. No estimate could be provided for t‐NPWT due to the low number of patients achieving wound closure. Device‐related AEs were more frequent in the t‐NPWT group (41 AEs from 29 patients) than in the s‐NPWT group (16 AEs from 12 patients). The s‐NPWT system met noninferiority and achieved statistical superiority vs. t‐NPWT in terms of wound progression toward healing over the treatment period. When NPWT is being considered for the management of challenging VLUs and DFUs, s‐NPWT should be considered a first choice over other types of NPWT.

Spatial-Temporal Changes of Mechanical Microenvironment in Skin Wounds During Negative Pressure Wound Therapy

Cell migration, proliferation, and differentiation are regulated by mechanical cues during skin wound healing. Negative pressure wound therapy (NPWT) reduces the healing period by optimizing the mechanical microenvironment of the wound bed. Under NPWT, it remains elusive how the mechanical microenvironment (e.g., stiffness, strain gradients) changes both in time and space during wound healing. To illustrate this, the healing time of full-thickness skin wounds under NPWT, with pressure settings ranging from -50 to -150 mm Hg, were evaluated and compared with gauze dressing treatments (control group), and three-dimensional finite element models of full-thickness skin wounds on days 1 and 5 after treatment were developed on the basis of MR 3D imaging data. Shear wave elastography (SWE) was applied to detect the stiffness of wound soft tissue on days 1 and 5, and nonlinear finite element analysis (FEA) was used to represent the spatial-temporal environment of the 3D strain field of the wound under NPWT vs the control group. Compared with the control group, NPWT with -50, -80, and -125 mm Hg promoted wound healing. SWE showed that the elastic modulus of wounded skin increased during healing. Meanwhile, the elastic modulus in wounded skin under NPWT was significantly smaller than in the control group. Strain and its gradient decreased under NPWT during wound healing, while no significant change was observed in the control group. This study, which is based on MR 3D imaging, shear wave elastography, and nonlinear FEA, provides an in-depth understanding of changes of the skin mechanical microenvironment under NPWT in the time-space dimension and the associated wound healing.

"Gravity" - a new simple negative pressure wound therapy self-build design for low income countries

Negative Pressure Wound Therapy (NPWT) is prohibitively expensive at the moment and therefore not easily accessible in low-income countries. An additional problem is the requirement of consistent reliable electricity to power the devices. A new low-cost NPWT device was designed from low cost and simple materials and it can be built and operated following a simple set of instructions. The so-called Gravity device was made from parts costing just under £6 GBP (May 2016) and it creates a constant pressure of 125 mmHg. Gravity operated from 4 hours and 40 minutes up to 5 hours and 18 minutes before needing to be reset. This reset can be achieved without patient involvement. Gravity was taken to Kenya by a Doctor on 5 May 2016 to be evaluated. A NPWT device prototype was successfully made and positive feedback was received from Kenya.

Feasibility of a disposable canister-free negative-pressure wound therapy (NPWT) device for treating open wounds in horses

BACKGROUND

Wounds are among the most common medical conditions affecting horses and have a major economic impact on the horse industry. Wound healing in horses is distinct to that documented in other species, and often results in delayed healing and extensive scarring, with compromised functional and aesthetic outcomes. To date, there is no conventional method objectively proven to accelerate healing or to successfully prevent complications associated with second intention healing. Several effects of Negative Pressure Wound Therapy (NPWT) may be particularly useful to the management of wounds in horses. However, cumbersome designs of classic NPWT devices render them unsuitable for equine practice. A new lightweight, portable and disposable unit of NPWT (PICO®), should facilitate the use of this modality by equine practitioners. The aim of this study was to evaluate the feasibility of using this canister-free system to treat experimental open wounds in horses.

RESULTS

No difficulties were encountered with the application or maintenance of the PICO® system during the ex vivo experiment or during the preliminary in vivo experiment conducted on intact skin. All horses readily tolerated the PICO® but difficulties with adhesion and seal prevented the completion of the experimental wound study despite the use of many adjunctive adhesives.

CONCLUSION

The current PICO® dressing design is not suitable to be used as a dressing for open wounds in horses though the device is well tolerated by equine patients. A dressing with a wider adhesive edge, a superior adhesive and a more flexible pad would likely be better adapted to enable its future use in equine practice.

Wound Management: Wounds with Special Challenges

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

Reducing Risks Associated With Negative-Pressure Wound Therapy: Strategies for Clinical Practice

Negative-pressure wound therapy represents a relatively new strategy for wound management. Significant, life-threatening complications (bleeding, infection, and retained dressing material) have been associated with negative-pressure wound therapy. As a result, the Food and Drug Administration published several warnings to negative-pressure wound therapy users and recommended that clinicians ordering, managing, and/or monitoring negative-pressure wound therapy be aware of the potential complications and be prepared to take prompt action to reduce patients' risk for harm. This article reviews and organizes published consensus, expert opinion, research, and manufacturer guidelines about patient safety during negative-pressure wound therapy relevant to nurses practicing in acute and critical care settings, including in advanced practice roles.

Use of controlled negative pressure in management of phlegmon caused by fulminant complication of pressure wound: A case report

RATIONALE

Effective wound healing depends on the adequate choice of the wound cleansing method, to enable rapid removal of necrotic tissue. Negative pressure wound therapy (NPWT) is an effective non-invasive technique for management of wounds of varied aetiology, including deep tissue injuries caused by pressure.

PATIENT CONCERNS

This article discusses a case of an 82-year-old female receiving hospice care at home owing to progressing untreated thoracic spinal stenosis, bedridden for 4 years, incapable of self-care.

DIAGNOSES

Three fulminant pressure wounds, 50 cm each, with signs of undermining, Stage II/IV according to National Pressure Ulcer Advisory Panel, were identified in the area of the sacrum and the right and left trochanter. Despite measures used to prevent pressure sores, and nutritional supplementation, two months later a fourth pressure ulcer involving subcutaneous tissue was identified in the area of the right sciatic tuber, accompanied with signs of systemic inflammatory response, as well as massive phlegmon and lesion in the ischial bone.

INTERVENTIONS

As previously applied treatments (surgical necrectomy, biological therapy - Lucilia Sericata maggots, autolysis, pharmacological therapy) proved ineffective, NPWT was experimentally administered to evacuate exudate and to cleanse the wound.

OUTCOMES

Application of negative pressure during a 42-day therapy allowed significantly faster cleansing of the wound. The pressure wounds was significantly reduced in size, and necrotic tissue was removed from the sciatic tuber, which ultimately was covered with granulation tissue.

LESSONS

Controlled negative pressure can successfully be used in the process of cleansing an infected pressure wound to safely remove exudate and to minimise local inflammation. Administration of controlled negative pressure is an effective and safe method in the process of cleansing an infected pressure wound.

Negative pressure therapy for the treatment of complex wounds

The objective of this study is to evaluate the effectiveness of negative pressure therapy (NPT) in the treatment of complex wounds, with emphasis on its mechanisms of action and main therapeutic indications. We searched the Pubmed / Medline database for articles published from 1997 to 2016, and selected the most relevant ones. The mechanisms of action of NPT involveboth physical effects, such as increased perfusion, control of edema and exudate, reduction of wound dimensions and bacterial clearance, and biological ones, such as the stimulation of granulation tissue formation, microdeformations and reduction of Inflammatory response. The main indications of NPT are complex wounds, such as pressure ulcers, traumatic wounds, operative wound dehiscences, burns, necrotizing wounds, venous ulcers, diabetic wounds, skin grafts, open abdomen, prevention of complications in closed incisions and in the association with instillation of solutions in infected wounds.

Negative pressure wound therapy in the management of mine blast injuries of lower limbs: Lessons learnt at a tertiary care center

Background

Mine blast injuries of foot are devastating injuries that result in composite tissue loss or amputations. Negative pressure wound therapy has helped in the management of such combat-related wounds. The aim of this study was to report experiences gained in managing such injuries at a tertiary care center.

Methods

17 combatants who sustained mine blast injuries were included in this study. Severity of foot injury was assessed as per Foot and Ankle Severity Score. After wound debridement, negative pressure wound therapy was started and foot defect was appropriately reconstructed. Following wound healing, the foot was assessed for Foot and Ankle Severity Score in terms of impairment. The patients were then suitably rehabilitated by shoe modifications, orthosis, or custom-made prosthesis.

Results

Mean age of soldiers who sustained mine blast injuries was 30.2 years. The mean Foot and Ankle Severity Score was 3.76. Temporary wound closure was achieved using negative pressure wound therapy and it prevented local and systemic infection. The defect could be reconstructed appropriately using split skin graft, regional fasciocutaneous flap, or microvascular free flap. Mean time to definitive reconstructive procedure was 16.5 days. Mean Foot and Ankle Severity Score in terms of impairment was 4.11. All soldiers could be rehabilitated and were returned to their respective units and were able to perform sedentary duties assigned to them.

Conclusion

The negative pressure wound therapy was helpful in preventing proximal amputations due to mine blast injury and was helpful in satisfactory reconstruction of foot defects.