Randomized clinical study to compare negative pressure wound therapy with simultaneous saline irrigation and traditional negative pressure wound therapy for complex foot infections

Does complete resection of infected bone improve clinical outcomes in patients with diabetic foot osteomyelitis?

The objective of the study was to compare outcomes in patients with complete surgical resection versus partial resection of diabetic foot osteomyelitis (OM). A post hoc analysis of 171 patients with OM was performed using data from two randomized clinical trials. OM was confirmed with bone culture or histopathology. Surgical culture specimens were obtained from resected bone and sent for histopathology and microbiology. Residual osteomyelitis (RO) was defined as a positive resected margin on culture or histopathology. No residual osteomyelitis (NRO) was defined as no growth from bone culture and no histopathological inflammation in the biopsy of the resection margin. Data from the 12-month follow-up were used to determine clinical outcomes. During the index hospitalization, NRO patients had significantly shorter duration of antibiotic therapy (NRO 21.0, 13.0-38.0 vs. RO 37.0, 20.8-50.0, p <0.01) and more amputations than patients with RO (NRO 89.9% vs. RO 60.9%, p <0.01). During the 12-month follow-up, patients with NRO also had significantly shorter duration of antibiotic therapy (NRO 42, 21.0-66.5 vs. RO 50.5, 35.0-75.0, p = 0.02). During the 12-month follow-up, there was no difference in ulceration at the same site (NRO 3.7%, RO 4.3% p = 0.85), hospitalization (NRO 32.6%, RO 34.8%, p = 0.76), total re-infections (NRO 25.3%, RO 29.3%, p = 0.56), re-infection with osteomyelitis (NRO 13.3% vs. 13.5%, p = 0.36), amputation (NRO 8.8%, RO 5.4%, p = 0.86) and time to wound healing in days (NRO 94, 41.0-365 vs. RO 106, 42.8-365, p = 0.77). Successful treatment of osteomyelitis was achieved by 86.7% and 86.5% of patients. During the index hospitalization, patients with no residual osteomyelitis had more amputations and were treated with antibiotics for a shorter duration. During the 12-month follow-up, patients with no residual osteomyelitis had shorter durations of antibiotics. There were no differences in re-infection, amputation, re-ulceration or hospitalization. Level of evidence: 1.

MRSA infection, re-infection and clinical outcomes in diabetic foot infections

The aim was to investigate methicillin-resistant Staphylococcus aureus (MRSA) incidence, conversion and outcomes in diabetic foot infections (DFIs). This is a pooled patient-level analysis of combined data sets from two randomised clinical trials including 219 patients admitted to the hospital with moderate or severe DFIs. Intraoperative bone and tissue cultures identified bacterial pathogens. We identified pathogens at index infections and subsequent re-infections. We identified MRSA conversion (MSSA to MRSA) in re-infections. MRSA incidence in index infections was 10.5%, with no difference between soft tissue infections (STIs) and osteomyelitis (OM). MRSA conversion occurred in 7.7% of the re-infections in patients who initially had MSSA in their cultures. Patients with re-infection were 2.2 times more likely to have MRSA compared to the first infection (10.5% vs. 25.8%, relative risk [RR] = 2.2, p = 0.001). Patients with MRSA had longer antibiotic treatment during the 1-year follow-up, compared to other pathogens (other 49.8 ± 34.7 days, MRSA 65.3 ± 41.5 days, p = 0.04). Furthermore, there were no differences in healing, time to heal, length of stay, re-infection, amputation, re-ulceration, re-admission, surgery after discharge and amputation after discharge compared to other pathogens. The incidence of MRSA at the index was 10.5% with no difference in STI and OM. MRSA incidence was 25.8% in re-infections. The RR of having MRSA was 2.2 times higher in re-infections. Patients with MRSA used more antibiotics during the 1-year follow-up. Furthermore, there were no differences in clinical outcomes compared to other bacterial pathogens.

3D bioprinting of Salvianolic acid B-sodium alginate-gelatin skin scaffolds promotes diabetic wound repair via antioxidant, anti-inflammatory, and proangiogenic effects

In patients with diabetic wounds, wound healing is impaired due to the presence of persistent oxidative stress, an altered inflammatory response, and impaired angiogenesis and epithelization. Salvianolic acid B (SAB), which is derived from the Chinese medicinal plant Salvia miltiorrhiza, has been found to exhibit antioxidant, anti-inflammatory, and proangiogenic effects. Previous studies have used 3D bioprinting technology incorporating sodium alginate (SA) and gelatin (Gel) as basic biomaterials to successfully produce artificial skin. In the current study, 3D bioprinting technology was used to incorporate SAB into SA-Gel to form a novel SAB-SA-Gel composite porous scaffold. The morphological characteristics, physicochemical characteristics, biocompatibility, and SAB release profile of the SAB-SA-Gel scaffolds were evaluated in vitro. In addition, the antioxidant, anti-inflammatory, and proangiogenic abilities of the SAB-SA-Gel scaffolds were evaluated in cells and in a rat model. Analysis demonstrated that 1.0 wt% (the percentage of SAB in the total weight of the solution containing SA and Gel) SAB-SA-Gel scaffolds had strong antioxidant, anti-inflammatory, and proangiogenic properties both in cells and in the rat model. The 1.0% SAB-SA-Gel scaffold reduced the expression of tumor necrosis factor-α, interleukin-6, and interluekin-1β and increased the expression of transforming growth factor-β. In addition, this scaffold removed excessive reactive oxygen species by increasing the expression of superoxide dismutase, thereby protecting fibroblasts from injury. The scaffold increased the expression of vascular endothelial growth factor and platelet/endothelial cell adhesion molecule-1, accelerated granulation tissue regeneration and collagen deposition, and promoted wound healing. These findings suggest that this innovative scaffold may have promise as a simple and efficient approach to managing diabetic wound repair.

Management of Hardware-Exposed Soft Tissue Defects Using Dermal Substitutes and Negative Pressure Wound Therapy

INTRODUCTION

Reconstruction of complex injuries of the extremities with full-thickness wounds is a challenging but important task. If primary closure is not feasible, more complex procedures are required, such as split-thickness skin graft or flap surgery. Recently, several studies have shown good results when combined with negative pressure wound therapy (NPWT) and artificial dermal replacement therapy after extensive surgical debridement and NPWT administration for severe complex wounds accompanied by tendon or bone exposure. However, flap surgery remains the only treatment for wounds in which the hardware is exposed after fracture fixation. Therefore, in this study, we attempted to prove the usefulness of the combined treatment using artificial dermal substitutes (MatriDerm) and NPWT by focusing on hardware-exposed wounds, which have not been studied before.

METHODS

From 2019 to 2021, we treated with our wound management procedure 14 patients with hardware-exposing wounds after internal fixation using plates, out of 48 patients with full-thickness posttraumatic skin defect. Before skin grafting, after surgical debridement and thorough washouts, MatriDerm was placed and NPWT was applied over it. This staged approach aimed at conditioning even the most complex wounds so that closure with MatriDerm-augmented skin grafting would become possible in a one-step approach.

RESULTS

We stratified the duration of treatment and number of replacements in NPWT according to the type of injury. Cases with open fractures required significantly longer NPWT than those with closed fractures (P = 0.01); however, there was no significant difference between the Gustilo-Anderson classification within open fractures (P > 0.05). Patients with open fractures underwent a mean of 6.6 changes while those with closed fractures underwent 2.5 (P = 0.002) until the final wound closure with MatriDerm-augmented skin grafting was performed. There was no significant difference in the treatment period based on the location and size of the wound, and there was no significant difference in the number of NPWT replacements. Skin grafting was successful in all 14 patients.

CONCLUSIONS

This study revealed that NPWT and artificial dermis-augmented skin grafting after combined treatment with NPWT and artificial dermis were sufficiently useful for hardware-exposed wounds, where flap surgery has been considered the only treatment to date.

A Prospective Analysis of the SVS WIfI Classification System to Stratify Immediate and 1-Year Patient Outcomes

The purpose of this study was to prospectively enroll patients that presented to the emergency department with a lower extremity infection, stratify risk and record outcomes. Risk stratification was performed based on the Society of Vascular Surgery Wound, foot Infection, and Ischemia (WIfI) classification system. This study aimed to establish the efficacy and validity of this classification in predicting patient outcomes during immediate hospitalization and throughout a 1 year follow up. A total of 152 patients were enrolled in the study and of these, 116 met the inclusion criteria and had at least 1 year of follow up for analysis. Each patient was assigned a WIfI score based on wound, ischemia, and foot infection severity according to the classification guidelines. Patient demographics as well as all podiatric and vascular procedures were recorded. The major end points of the study were rates of proximal amputation, time to wound healing, surgical procedures, surgical dehiscence, readmission rates, and mortality. A difference in rates of healing (p = .04), surgical dehiscence (p < .01), and 1 year mortality (p = .01) with increasing WIfI stage as well as across the individual component scores was noted. This analysis further supports the application of the WIfI classification system early during patient care to stratify risk and identify the need for early intervention and a multispecialty team approach to potentially improve outcomes in the severe multicomorbid patient.

Clinical outcomes of negative pressure wound therapy with instillation vs standard negative pressure wound therapy for wounds: A meta‐analysis of randomised controlled trials

Negative pressure wound therapy (NPWT) with or without instillation has been extensively applied for patients with multiple wound types. Whether NPWT with instillation is superior to NPWT alone is not known. This study aims to compare the efficacy between negative pressure wound therapy with instillation (NPWTi) and standard negative pressure wound therapy for wounds. The authors searched for randomised controlled trials (RCTs) in PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials investigating clinical outcomes of negative pressure wound therapy with instillation vs standard negative pressure wound therapy for wounds. The registration number (protocol) on PROSPERO is CRD42022287178. Eight RCTs involved 564 patients met the inclusion criteria and were included finally. NPWTi showed a significant fewer surgeries and dressing changes (RR and 95% CI, -9.31 [-17.54, -1.08], P < 0.05), and smaller wound area after treatment (RR and 95% CI, -9.31 [-17.54, -1.08], P < 0.05) compared with NPWT. No significant difference was observed on healing rate, time to heal, length of stay, dehiscence, reinfection, reoperation and readmission between NPWTi and NPWT. The addition of instillation to NPWT could improve clinical outcomes regarding the number of surgeries and dressing changes, and wound area after treatment in patients with multiple wound types. However, because of the heterogeneity these conclusions still need to be further validated by more well-designed RCTs with large sample sizes.

Therapeutic Effect and Mechanism of Negative Pressure Wound Therapy with Huoxue Shengji Decoction Instillation for Chronic Skin Ulcers

Background

Negative pressure wound therapy (NPWT) with instillation (NPWTi) is a new treatment for chronic skin ulcers (CSUs), but the choice of perfusate is still investigated. The clinical application of Huoxue Shengji (HXSJ) decoction has been proved to promote the formation of granulation. The formation of fresh granulation, angiogenesis, and proliferation of vascular endothelial cells are closely related. The purpose of this study was to observe the clinical efficacy of NWPT with HXSJ decoction instillation in the treatment of CSUs and to explore the potential mechanism by which HXSJ decoction promotes proliferation of vascular endothelial cells at the cellular level.

Methods

In the clinical study, the random number table was used to divide the patients into three groups (patients were numbered by visit time and assigned a random number and grouped by the remainder after the random number was divided by 3, and when the number of patients in one group reached 20, the enrolment of this group is stopped), including NPWT combined with HXSJ decoction instillation (group A), NPWT combined with normal saline instillation (group B), and NPWT (group C). Related indexes were examined, including the wound cavity volume, bacterial culture, histopathology examination, time periods of debridement, repair methods, and the time of ulcer healing. In the basic research, the effect of HXSJ decoction on the proliferation of HUVECs was analysed by CCK-8 assay and RT-PCR and western blot were used to quantify the VEGF and VEGFR-2 expression in the relevant signalling pathway.

Results

There was no significant difference in the improvement rate of invasive cavity volume (P > 0.05) between groups A and B, but a significant difference was observed between groups A and C (P < 0.05). There was no significant difference in microbial reduction among groups (all P > 0.05). Histopathological examination showed that the microvascular count in group A was significantly higher than that in groups B and C (both P < 0.01) and there was no statistical difference between groups B and C (P > 0.05). There were no significant differences in the number of invasive lesions and repair methods among the groups (all P > 0.05). The healing time of group A was significantly faster than those of groups B and C (compared to group B, P < 0.05; compared to group C, P < 0.01), and there was no statistical difference between groups B and C (P > 0.05). In the cellular experiments, concentration screening was performed and 125 μg/mL HXSJ decoction showed the most significant effect on the proliferation of HUVECs and also enhanced the expression of VEGF and VEGFR-2.

Conclusion

HXSJ decoction can enhance the expression of VEGF and VEGFR-2 and promote the proliferation of HUVECs. Treatment with NWPT with HXSJ decoction instillation can further reduce the wound cavity volume; meanwhile, it can promote blood vessel formation in ulcer wounds, thus accelerating the healing of CSUs.

The Effect of Negative-Pressure Wound Therapy with Instillation Compared to Current Standard Care on Wound Closure Time of Infected Wounds: A Systematic Review and Meta-Analysis

BACKGROUND

Infected wounds extend healing time and are associated with higher treatment costs than noninfected wounds. Several observational studies indicate that negative-pressure wound therapy with instillation can effectively reduce bacterial bioburden and improve wound healing. Only a few randomized trials with small sample sizes have been published, and a meta-analysis directly comparing negative-pressure wound therapy with instillation to current standard care is lacking. It is therefore uncertain whether negative-pressure wound therapy with instillation actually improves wound healing. The authors performed a systematic review and hypothesized that negative-pressure wound therapy with instillation reduces wound closure time.

METHODS

The PubMed, Embase, and CENTRAL databases were searched up to December of 2020 for English studies that compare negative-pressure wound therapy with instillation-to either negative-pressure wound therapy without instillation or to other types of wound care-for the treatment of acute or chronically infected wounds. Time to wound closure was analyzed using a random effects meta-analysis in predefined subgroups according to study design and comparative wound care.

RESULTS

The authors identified 14 studies describing 1053 patients. Meta-analysis of three randomized trials shows no significant difference in time to wound closure between negative-pressure wound therapy with instillation and that without (mean difference, 0.48 day; 95 percent CI, -0.70 to 1.65; I ² = 0 percent). Data from eleven observational studies indicate that negative-pressure wound therapy with instillation reduces wound closure time (from 1.6 to 16.8 days; no pooled data). Because of imprecision and risk of bias, the available evidence provides only low-level certainty.

CONCLUSIONS

There is currently insufficient evidence to support or discard the use of negative-pressure wound therapy with instillation for infected wounds. More randomized trials are needed to determine whether a beneficial effect can be substantiated.

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.

Modified negative pressure wound therapy as an adjunct to antibiotics in the treatment of orthopaedic infected metalwork

Purpose

Infected orthopaedic metalwork is challenging to treat. Negative pressure wound therapy (NPWT) with irrigation is an emerging therapy for infected wounds as an adjunct to antibiotic therapy. The senior author had devised a modified technique to augment its efficacy, utilising high-flow rate irrigation and skin closure over the standard NPWT dressing. This novel technique was originally evaluated in a different centre and produced 100% success in metalwork retention. The present study is a reproducibility test of the same technique.

Methods

A retrospective review was performed on 24 patients with infected orthopaedic metalwork, including 3 upper limb and 21 lower limb cases, for outcomes relating to implant retention and infection resolution. Patients underwent a modified NPWT technique as an adjunct to antibiotic therapy and surgical debridement. Detailed medical and microbiology information were obtained from the patient records.

Results

23 of 24 (96%) patients had successful metalwork retainment with healed wounds and resolution of infection, allowing fracture union. 27 infective organisms were identified in this cohort, and the antibiotic regimens for each patient are provided. The average follow-up was 663 days. No adverse effects were observed.

Conclusion

This series supports the modified NPWT technique as a safe, reliable and effective adjunct therapy to resolve metalwork infection. The same results have been reproduced as the previous cohort in a different centre.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00590-021-03135-5.

Evidence-Based Wound Irrigation: Separating Fact from Fiction

SUMMARY

The relationship between wound irrigation and healing has been recognized for centuries. However, there is little evidence and no official recommendations from any health care organization regarding best wound irrigation practices. This is the first review of wound irrigation that systematically summarizes the literature using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and distills the evidence into a practical format. In this comprehensive review, the authors outline the irrigation fluids and delivery methods used in the identified studies, analyze reported treatment outcomes, summarize irrigation effectiveness, and propose evidence-based guidelines to improve wound healing outcomes and enhance the consistency of wound irrigation. Thirty-one high-quality studies with a combined total of 61,808 patients were included. Based on the current evidence provided by this review, the authors propose the following guidelines: (1) acute soft-tissue wounds should receive continuous gravity flow irrigation with polyhexanide; (2) complex wounds should receive continuous negative-pressure wound therapy with instillation with polyhexanide; (3) infected wounds should receive continuous negative-pressure wound therapy with instillation with silver nitrate, polyhexanide, acetic acid, or povidone-iodine; (4) breast implant wounds should receive gravity lavage with povidone-iodine or antibiotics; and (5) surgical-site infection rates can be reduced with intraoperative povidone-iodine irrigation.

Long-term experience with a collagen-elastin scaffold in combination with split-thickness skin grafts for the treatment of full-thickness soft tissue defects: improvements in outcome-a retrospective cohort study and case report

Purpose

The management of severe soft tissue injuries to the extremities with full-thickness wounds poses a challenge to the patient and surgeon. Dermal substitutes are used increasingly in these defects. The aim of this study was to investigate the impact of the type of injury on the success rate of Matriderm® (MD)-augmented split-thickness skin grafting, as well as the role of negative pressure wound therapy (NPWT) in preconditioning of the wounds, with a special focus on the reduction of the bioburden.

Methods

In this study, 45 wounds (44 affecting lower extremities (97.7%)), resulting from different types of injuries: soft tissue (ST), soft tissue complications from closed fracture (F), and open fracture (OF) in 43 patients (age 55.0 ± 18.2 years, 46.7% female), were treated with the simultaneous application of MD and split-thickness skin grafting. The study was designed as a retrospective cohort study from March 2013 to March 2020. Patients were stratified into three groups: ST, F, and OF. Outcome variables were defined as the recurrence of treated wound defects, which required revision surgery, and the reduction of bioburden in terms of reduction of number of different bacterial strains. For statistical analysis, Student’s t-test, analysis of variance (ANOVA), Mann–Whitney U test, and Pearson’s chi-squared test were used.

Results

There was no significant difference in the rate of recurrence in the different groups (F: 0%; OF: 11.1%; ST: 9.5%). The duration of VAC therapy significantly differed between the groups (F: 10.8 days; OF: 22.7 days; ST: 12.6 days (p < 0.05)). A clinically significant reduction of bioburden was achieved with NPWT (bacterial shift (mean (SD), F: − 2.25 (1.89); OF: − 1.9 (1.37); ST: − 2.6 (2.2)).

Conclusion

MD-augmented split-thickness skin grafting is an appropriate treatment option for full-thickness wounds with take rates of about 90%. The complexity of an injury significantly impacts the duration of the soft tissue treatment but does not have an influence on the take rate. NPWT leads to a relevant reduction of bioburden and is therefore an important part in the preconditioning of full-thickness wounds.

Cost-minimization analysis of negative pressure wound therapy technologies for the treatment of moderate-to-severe foot infections

Aim: The objective was to estimate the cost of care associated with two negative pressure wound therapy (NPWT) technologies used to treat patients admitted to the hospital with moderate-to-severe foot infections. Materials & methods: A decision tree simulation model was developed to estimate the hospital costs associated with two different NPWT technologies: Cardinal Health™ PRO (NPWT-C) and V.A.C. ULTA™ (NPWT-K). Clinical data were obtained from a previously completed single-site prospective trial. One-way and probabilistic sensitivity analyses were performed to gauge the robustness of the results. Results: The total expected per-patient costs were US$41,206 (SD: US$8,194) for NPWT-C and US$44,439 (SD: US$8,963) for NPWT-K. Conclusion: This study found that NPWT-C was expected to minimize the total costs over the episode of treatment. Larger and more clinically diverse studies are recommended to confirm these findings.

Does negative pressure wound therapy with irrigation improve clinical outcomes? A randomized clinical trial in patients with diabetic foot infections

AIM

To compare the efficacy of Negative Pressure Wound Therapy (NPWT) with and without irrigation with 0.1% polyhexanide-betaine.

METHODS

We randomized 150 subjects in a 16-week RCT to compare healing in patients with diabetic foot infections. NPWT delivered at 125 mm Hg continuous pressure. NPWT-I were administered at 30 cc per hour.

RESULTS

There were no differences clinical treatment or outcomes: wound area after surgery (18.5 ± 19.0 vs. 13.4 ± 11.1 cm2, p = 0.50), duration of antibiotics (39.7 ± 21.0 vs. 38.0 ± 24.6 days, p = 0.40), number of surgeries (2.3 ± 0.67 vs. 2.2 ± 0.59, p = 0.85), duration of NPWT (148.1 ± 170.4 vs. 114.5 ± 135.1 h, p = 0.06), healed wounds (58.7% vs. 60.0%, p = 0.86), time to healing (56.3 ± 31.7 vs. 50.7 ± 27.8, p = 0.53), length of stay (13.8 ± 6.4 vs. 14.5 ± 11.2 days, p = 0.42), re-infection (20.0% vs. 22.7%, p = 0.69, and re-hospitalization (17.3% vs. 18.7, p = 0.83).

CONCLUSIONS

The addition of irrigation to NPWT did not change clinical outcomes in patients with diabetic foot infections.

CLINICAL TRIAL NUMBER

NCT02463487, ClinicalTrials.gov.