A new mechanism in negative pressure wound therapy: interleukin-17 alters chromatin accessibility profiling.

Negative pressure wound therapy (NPWT) is extensively used in clinical settings to enhance the healing of wounds. Despite its widespread use, the molecular mechanisms driving the efficacy of NPWT have not been fully elucidated. In this study, skin wound-healing models were established, with administration of NPWT. Vimentin, collagen I, and MMP9 of skin tissues were detected by immunofluorescence (IF). Gene expression analysis of skin wound tissues was performed by RNA-sequencing (RNA-seq). Protein expression was assayed by a Western blotting or IF assay, and mRNA levels were quantified by quantitative PCR. Chromatin accessibility profiles of fibroblasts following NPWT or IL-17 exposure were analyzed by ATAC-seq. In rat wound-healing models, NPWT promoted wound repair by promoting reepithelialization, extracellular matrix (ECM) synthesis, and proliferation, which mainly occurred in the early stage of wound healing. These differentially expressed genes (DEGs) in NPWT wounds versus control wounds were enriched in the IL-17 signaling pathway. IL-17 was identified as an upregulated factor following NPWT in skin wounds. Moreover, the IL-17 inhibitor secukinumab (SEC) could abolish the promoting effect of NPWT on wound healing. Importantly, chromatin accessibility profiles were altered following NPWT and IL-17 stimulation in skin fibroblasts. Our findings suggest that NPWT upregulates IL-17 to promote wound healing by altering chromatin accessibility, which is a novel mechanism for NPWT's efficacy in wound healing.NEW & NOTEWORTHY To our knowledge, this is the first report of the efficacy of negative pressure wound therapy (NPWT) in promoting wound healing via IL-17. Moreover, NPWT and IL-17 can alter chromatin accessibility. Our study identifies a novel mechanism for NPWT's efficacy in wound healing.

Association of negative pressure wound therapy and surgical site infections in patients undergoing cytoreductive surgery: An entropy balanced analysis.

BACKGROUND AND OBJECTIVES: Surgical site infections (SSIs) after cytoreductive surgery (CRS) ± hyperthermic intraperitoneal chemotherapy (HIPEC) are a major cause of potentially avoidable morbidity. We explored the association of negative pressure wound therapy (NPWT) with SSI in patients undergoing CRS/HIPEC. METHODS: Retrospective analysis of consecutive patients undergoing CRS/HIPEC for non-gynecologic cancers. Exposure was the receipt of NPWT versus traditional skin closure. Primary outcome was SSI within 90 days of surgery. We performed multivariable logistic regression (before and after entropy balancing) to evaluate the association of exposure with outcomes. RESULTS: A total of 251 patients were included, of which 43 (17%) received NPWT and 26 (10.4%) developed SSIs. Baseline demographics and clinicopathologic characteristics were similar between the two groups with some exceptions: Patients who received NPWT had a higher Peritoneal Carcinomatosis Index (median 19 vs. 11, p = 0.002) and operative time (10 vs. 8.2 h, p = 0.003) but were less likely to undergo HIPEC (84% vs. 95%, p < 0.05). After entropy balancing, on multivariable logistic regression, NPWT was not associated with 90-day SSI (odds ratio = 0.90; 95% confidence interval = 0.21-3.80; p = 0.89). CONCLUSION: NPWT was not associated with a reduction in SSIs. These findings prompt a reevaluation of the routine use of NPWT in CRS/HIPEC.

Surgical limits, pitfalls, and potential solutions in kyphectomy in myelomeningocele: three cases and systematic review of the literature.

OBJECTIVES: To describe surgical treatment of 3 cases of severe and progressive thoracolumbar kyphosis in myelomeningocele and provide a systematic review of the available literature on the topic. METHODS: Medical records and pre- and post-operative imaging of 3 patients with thoracolumbar kyphosis and myelomeningocele were reviewed. A database search was performed for all manuscripts published on kyphectomy and/or surgical treatment of kyphosis in myelomeningocele. Patients' information, preoperative kyphosis angle, type of surgery, levels of surgery degrees of correction after surgery and at follow-up, and complications were reviewed for the included studies. RESULTS: Three cases underwent posterior vertebral column resection (pVCR) of 2-4 segments at the apex of the kyphosis (kyphectomy). Long instrumentation was performed with all pedicle screws constructed from the thoracic spine to the pelvis using iliac screws. According to literature review, a total of 586 children were treated for vertebral kyphosis related to myelomeningocele. At least one vertebra was excised to gain some degree of correction of the deformity. Different types of instrumentation were used over time and none of them demonstrated to be superior over the other. CONCLUSION: Surgical treatment of progressive kyphosis in myelomeningocele has evolved over the years incorporating all major advances in spinal instrumentation techniques. Certainly, the best results in terms of preservation of correction after surgery and less revision rates were obtained with long construct and screws. However, complication rate remains high with skin problems being the most common complication. The use of low-profile instrumentation remains critical for treatment of these patients.

Negative pressure wound therapy with instillation and dwell time in debridement of fibrinous leg ulcers.

OBJECTIVE: In conjunction with appropriate wound care, negative pressure wound therapy with instillation and dwell time (NPWTi-d) may be used as an adjunct therapy for acute or hard-to-heal (chronic) wounds, especially when infected. However, there are very few data on the use of NPWTi-d in the treatment of fibrinous wounds that are difficult to debride mechanically. The main objective of this study was to describe changes in the fibrin area of such wounds, before and after treatment with NPWTi-d. METHOD: This was a monocentric, observational, prospective pilot study evaluating the NPWTi-d medical device. Eligible patients included in the study were those with hard-to-heal lower limb ulcers who had previously undergone unsuccessful specific debridement treatment for their wound, with failure of manual mechanic debridement for at least six weeks' duration, and whose wounds had a fibrinous surface area of >70% of the total wound surface area. The primary endpoint was the difference in the percentage of fibrinous surface area before and after treatment. RESULTS: A total of 14 patients who received treatment for lower limb ulcers between October 2017 and August 2019 were included in the study. There was a significant shrinkage rate of the fibrinous wound surface between the start and end of treatment (83.6±14.5% and 32.2±19.7%, respectively; p<0.001). CONCLUSION: This study showed a significant decrease in fibrin area in wounds treated with NPWTi-d, with good tolerance. We believe that NPWTi-d has its place in the multidisciplinary management of patients with hard-to-heal ulcers. Additional randomised studies are required to confirm these findings. DECLARATION OF INTEREST: The authors have no conflicts of interest.

Deciphering Early-Stage Molecular Mechanisms of Negative Pressure Wound Therapy in a Murine Model.

Negative Pressure Wound Therapy (NPWT) is a commonly employed clinical strategy for wound healing, yet its early-stage mechanisms remain poorly understood. To address this knowledge gap and overcome the limitations of human trials, we establish an NPWT C57BL/6JNarl mouse model to investigate the molecular mechanisms involved in NPWT. In this study, we investigate the intricate molecular mechanisms through which NPWT expedites wound healing. Our focus is on NPWT's modulation of inflammatory immune responses and the concurrent orchestration of multiple signal transduction pathways, resulting in shortened coagulation time and reduced inflammation. Notably, we observe a significant rise in dickkopf-related protein 1 (DKK-1) concentration during NPWT, promoting the differentiation of Hair Follicle Stem Cells (HFSCs) into epidermal cells, expediting wound closure. Under negative pressure, macrophages express and release DKK-1 cytokines, crucial for stimulating HFSC differentiation, as validated in animal experiments and in vitro studies. Our findings illuminate the inflammatory dynamics under NPWT, revealing potential signal transduction pathways. The proposed framework, involving early hemostasis, balanced inflammation, and macrophage-mediated DKK-1 induction, provides a novel perspective on enhancing wound healing during NPWT. Furthermore, these insights lay the groundwork for future pharmacological advancements in managing extensive wounds, opening avenues for targeted therapeutic interventions in wound care.

[Use of meglumine sodium succinate and NPWT therapy in the treatment of early and late complications of cholelistics]. / Ispol'zovanie meglyumina natriya suktsinata i NRWT-terapii v lechenii rannikh i pozdnikh oslozhnenii zhelchnokamennoi bolezni.

Gallstone disease remains an important medical and socially significant problem due to the increase in the proportion of patients of young and working age. At the same time, along with the increase in incidence, the number of complicated forms, such as choledocholithiasis in combination with stenosing duodenal papillitis (SDP) and obstructive jaundice, is increasing, which increases the importance of surgical approaches in the complex treatment of the disease and expands the range of conservative methods of therapy. In the given clinical observation of a young patient with severe cholelithiasis, accompanied by early and late complications, including the formation of postoperative scars and ventral hernias. At the last of the described stages of treatment during allohernioplasty, a complication developed in the form of a seroma followed by phlegmon of the anterior abdominal wall in the area of the implant, which served as the basis for including both local (NPWT therapy) and general (a course of infusions of a succinate-containing drug) methods in the treatment regimen, which contributed to more pronounced positive dynamics of the patient's condition.

Preclinical assessment of novel longer-duration wear negative pressure wound therapy dressing in a porcine model.

While reticulated open cell foam (ROCF) is a well-established dressing for negative pressure wound therapy (NPWT), there is the known potential for granulation tissue ingrowth if left in place for longer than 72 h. This may cause wound bed disruption, bleeding, and pain upon dressing removal. In addition, any retained foam fragments may elicit an adverse tissue reaction. A novel, easy to use dressing designed to utilise the advantages of ROCF while addressing its challenges has recently been created. This 7 day study investigated the utility of a novel NPWT dressing under longer-duration wear circumstances while assessing the prevalence of tissue ingrowth and ease of dressing removal in full-thickness excisional wounds utilising a porcine model. Histopathology and morphometry evaluations indicated thicker granulation tissue with, depending on the parameters assessed, either comparable or better tissue quality for wounds treated with the novel dressing. Greater re-epithelialization levels were also evident compared with ROCF. Three-dimensional imaging analysis indicated faster wound fill with a corresponding decrease in wound area with the novel dressing. Furthermore, tissue ingrowth was limited to only ROCF-treated wounds, which was not unexpected in this longer-duration wear study. The force required to remove the novel dressing was considerably lower compared with ROCF, correlating to the tissue ingrowth results. Results of this study illustrate that the novel dressing provided more favourable wound healing results compared with traditional ROCF. In addition, reduction in the risk of tissue ingrowth and low dressing peel force may allow it to be used as a longer-wear dressing.

Comparison of surgical site infection (SSI) between negative pressure wound therapy (NPWT) assisted delayed primary closure and conventional delayed primary closure in grossly contaminated emergency abdominal surgeries: a randomized controlled trial.

PURPOSE: NPWT has been tried in many surgical fields, including colorectal, thoracic, vascular, and non-healing wounds, for the prevention of SSI. However, its efficacy in the prevention of SSI-grade IV closed abdominal wounds is yet to be explored. METHODS: All patients with grade IV abdominal wounds were included in the study. They were randomized into the conventional arm and the VAC arm after confirming the diagnosis intra-operatively. The sheath was closed, and the skin was laid open in the postoperative period. In the VAC arm, the NPWT dressing was applied on postoperative day (POD)-1 and removed on POD-5. In the conventional arm, only regular dressing was done postoperatively. The skin was closed with a delayed primary intention on POD-5 in both arms. The sutures were removed after 7 to 10 days of skin closure. RESULTS: The rate of SSI (10% in the VAC arm vs. 37.5% in the conventional arm, p-value = 0.004) was significantly lower in the VAC arm, as were the rates of seroma formation (2.4% in the VAC arm vs. 20% in the conventional arm, p = 0.014) and wound dehiscence (7.3% vs. 30%, p = 0.011). The conventional arm had a significant delay in skin closure beyond POD5 due to an increased rate of SSI, which also led to a prolonged hospital stay (5 days in the VAC arm vs. 6.5 days in the conventional arm, p-value = 0.005). CONCLUSION: The VAC dressing can be used routinely in grade IV closed abdominal wounds to reduce the risk of SSI and wound dehiscence.

Prophylactic negative pressure wound therapy following colorectal perforation: defining the risk factors for delayed wound healing.

PURPOSE: The World Health Organization recommends prophylactic negative pressure wound therapy (NPWT) for high-risk SSI wounds, despite which delayed wound healing (DWH) remains a problem. The aim of this study was to define the risk factors for DWH under prophylactic NPWT following colorectal perforation (CP). METHODS: The subjects of this retrospective study were patients who underwent emergency laparotomy and prophylactic NPWT for CP between 2011 and 2019 at Fujisawa City Hospital in Japan. Multivariable analysis was performed to identify which perioperative factors impact DWH. RESULTS: A total of 58 patients met the inclusion criteria and the median period from surgery to wound closure was 12 days (IQR: 8-18). Most factors, including preoperative steroid use, diabetes, and serum albumin, were not associated with DWH, although patients requiring catecholamine were more likely to have DWH (OR 7.81, 95% CI 1.55-39.24, p = 0.013). The median in-hospital cost was more than double for patients with DWH vs. those without DWH (41.36 kUSD [IQR 24.95-51.89] vs. 20.32 kUSD [IQR 16.69-28.45], p < 0.001). CONCLUSION: Catecholamine use was a greater risk factor for DWH than previously reported factors such as diabetes and the serum albumin level. Further study is needed to investigate strategies to prevent DWH and optimize the utilization of NPWT, especially in patients requiring catecholamine.

Efficacy of prophylactic negative pressure wound therapy after open ventral hernia repair: a systematic review meta-analysis.

INTRODUCTION: The susceptibility to surgical site occurrence (SSO) is high following ventral hernia repair (VHR) surgery. SSO severely increases the physical and mental burden on patients. The main purpose of this review was to analyze the efficacy of negative pressure wound therapy (NPWT) after open VHR(OVHR) and explore benefits to patients. METHODS: The Cochrane Library, PubMed, and Embase databases were searched from the date of establishment to 15 October 2022. All randomized controlled trials and retrospective cohort studies comparing NPWT with standard dressings after OVHR were included. The Revman 5.4 software recommended by Cochrane and the STATA16 software were used in this meta-analysis. RESULTS: Fifteen studies (involving 1666 patients) were identified and included in the meta-analysis, with 821 patients receiving NPWT. Overall, the incidence rate of SSO in the NPWT group was lower compared to the control group (odds ratio [OR] = 0.44; 95% confidence interval [CI] = 0.21-0.93; I2 = 86%; P = 0.03). The occurrence rate of surgical site infection (SSI; OR = 0.51; 95% CI = 0.38-0.68, P < 0.001), wound dehiscence (OR = 0.64; 95% CI = 0. 43-0.96; P = 0.03), and hernia recurrence (OR = 0.51; 95% CI = 0.28-0.91, P = 0.02) was also lowered. There was no significant difference in seroma (OR = 0.76; 95% CI = 0.54-1.06; P = 0.11), hematoma (OR = 0.53; 95% CI = 0.25-1.11; P = 0.09), or skin necrosis (OR = 0.83; 95% CI = 0.47-1.46; P = 0.52). CONCLUSION: NPWT can effectively decrease the occurrence of SSO, SSI wound dehiscence and hernia recurrence and should be considered following OVHR.

Biodegradable temporising matrix: use of negative pressure wound therapy shows a significantly higher success rate.

OBJECTIVE: The purpose of this case series was to evaluate the efficacy of a synthetic biodegradable temporising matrix (BTM; PolyNovo Biomaterials Pty Ltd, Australia) and compare the outcome of BTM patients with and without negative pressure wound therapy (NPWT). METHOD: A retrospective chart review was conducted on patients admitted with deep full-thickness burns, traumatic or complex wound injuries treated with BTM. Electronic medical records and images were evaluated by a team of clinical professionals. Endpoints included: the measure of successful BTM integration; and comparison between patients treated with and without NPWT. Additional measures were BTM total surface area, BTM sites, timeliness of BTM application and any complications. RESULTS: A total of 28 patients were evaluated and 23 (82.1%) demonstrated overall successful BTM integration. Patients treated with BTM in conjunction with NPWT (n=16) demonstrated a significantly higher (p=0.046) integration rate compared to patients treated without NPWT (n=12) (93.8% versus 58.3%, respectively). Patients treated with BTM with NPWT continued to successfully integrate and sustain favourable outcomes despite the presence of severe infection or the development of haematomas. CONCLUSION: A significantly higher integration rate was demonstrated when BTM was used in conjunction with NPWT. The results of this study further support the efficacy of successful integration of BTM as a replacement for tissue loss in the treatment of deep, full-thickness burns, traumatic and complex wound injuries, and particularly favourable outcomes with the use of NPWT. To the best of our knowledge, this is the first reported case series comparing the clinical outcomes of BTM with and without the use of NPWT.

Is vacuum-assisted closure therapy the main culprit in right ventricular rupture after deep sternal wound infection?

Right ventricular rupture after deep sternal wound infection (DSWI) is a rare but fatal complication, and can occur with or without vacuum assisted closure (VAC) therapy. There is currently no strong evidence to suggest whether or not VAC therapy is a contributing factor to this complication. In total, 30 articles were retrieved and assessed through a systematic review strategy from 1953 to 2022. The keywords: 'vacuum assisted closure'; 'VAC'; 'negative pressure wound therapy'; 'deep sternal wound infection'; 'DSWI'; 'right ventricular rupture'; and 'cardiac rupture' were used in the search. Overall, 15 of the included articles satisfied the predefined eligibility criteria. Fatal right ventricular ruptures were reported in 18 (36%) out of 50 cases. In this article, the risk factors, mechanisms and management of right ventricular rupture are discussed. A novel view of the mechanism of VAC-associated right ventricular rupture is highlighted, with a focus on both pre- and intraoperative management.

Use of negative pressure wound therapy on locoregional flaps: a case-control study.

OBJECTIVE: The use of negative pressure wound therapy (NPWT) is ubiquitous in the management of complex wounds. Extending beyond the traditional utility of NPWT, it has been used after reconstructive flap surgery in a few case series. The authors sought to investigate the outcomes of NPWT use on flap reconstruction in a case-control study. METHOD: Patients who underwent flap reconstruction between November 2017 and January 2020 were reviewed for inclusion in the study, and divided into an NPWT group and a control group. For patients in the NPWT group, NPWT was used directly over the locoregional flap immediately post-surgery for 4-7 days, before switching to conventional dressings. The control group used conventional dressing materials immediately post-surgery. Outcome measures such as flap necrosis, surgical site infections (SSIs), wound dehiscence as well as time to full functional recovery and hospitalisation duration were evaluated. RESULTS: Of the 138 patients who underwent flap reconstruction, 37 who had free flap reconstructions were excluded, and 101 patients were included and divided into two groups: 51 patients in the NPWT group and 50 patients in the control group. Both groups had similar patient demographics, and patient and wound risk factors for impaired wound healing. Results showed that there was no statistically significant difference between flap necrosis, SSIs, wound dehiscence, hospitalisation duration as well as functional recovery rates. Cost analysis showed that the use of NPWT over flaps for the first seven postoperative days may potentially be more cost effective in our setting. CONCLUSION: In this study, the appropriate use of NPWT over flaps was safe and efficacious in the immediate postoperative setting, and was not inferior to the conventional dressings used for reconstructive flap surgery. The main benefits of NPWT over flaps include better exudate management, oedema reduction and potential cost savings. Further studies would be required to ascertain any further benefit.

The early association of water irrigation with negative pressure wound therapy does not more efficiently reduce the depth of the alkali infiltration progress into the burn.

Water irrigation is an efficacious decontaminating method for dermis exposures to corrosive agents and hence has been widely applied to treat especially alkali burns. Nevertheless, once alkali has infiltrated the deep subcutaneous tissue, washing the tissue surface with water irrigation does not attenuate the damage progress. Therefore, significant efforts have been devoted to promising strategies aimed at removing the deeply infiltrated lye. According to a recent report, the negative pressure wound therapy (NPWT) reduces the pH value of the exudate from alkali-provoked burns thus accelerating wound healing. However, it remains to be ascertained whether or not NPWT coupled with water irrigation, that is, iNPWT, more effectively hinders the alkali injury deepening. In this study, we compared the effectiveness of an early application of water irrigation with or without NPWT in preventing the progressive deepening of the alkali burn in an animal model. Our histological examination results showed no appreciable difference in tissue injury depth, dermal retention, inflammatory cell infiltration, re-epithelization, and cellular function between iNPWT and water irrigation alone treatments. Thus, our results prove that the more expensive NPWT coupled with water irrigation does not more effectively hinder the alkali's injury deepening. Hence, iNPWT use should be more cautious in clinical practice.

Effects of negative pressure wound therapy with instillation and dwell time (NPWTi-d) versus NPWT or standard of care in orthoplastic surgery: A systematic review and meta-analysis.

Negative pressure wound therapy (NPWT) is a wound-dressing system that applies sub-atmospheric pressure on the surface of a wound to promote healing. An evolution of this technology, NPWT with solution instillation and dwell time (NPWTi-d), is increasingly being used to maximise wound closure and reduce failure rates. However, there is still a lack of evidence concerning its use in orthoplastic surgery. Therefore, the aim of this study is to compare NPWTi-d with NPWT and standard of care for wound management in orthoplastic surgery. A comprehensive literature search using PubMed, Web of Science, and Cochrane databases up to 15 March 2022 was performed, including studies describing the outcomes of NPWTi-d for traumatic/orthopaedic injuries. A meta-analysis on the number of surgical debridements, as well as the rate of complete wound closure and complications was carried out, although for other outcomes, a descriptive statistic was applied. Risk of bias and quality of evidence were assessed using the Downs& Black's Checklist for Measuring Quality. Thirteen studies with a total number of 871 patients were included, in which NPWTi-d demonstrated significantly higher primary wound closure and lower complication rates (P < .05). No difference in the number of surgical procedures required for final wound healing was observed. Moreover, five out of six studies showed better results for NPWTi-d when the change of the bioburden and bacterial count of the wound were analysed. A singular study investigating the length of the hospital stay of patients treated with NPWTi-d showed a reduction in the latter. The present meta-analysis proves that NPWTi-d is superior to NPTW or conventional dressings in orthoplastic wound care management, in terms of complete wound closure rate and the reduced number of complications. Still, the limited quality of the studies analysed shows that future randomised studies are needed to confirm the benefits and to identify the most appropriate recommendations for using NPWTi-d in orthoplastic surgery, as well as to investigate the cost-effectiveness of this wound-dressing system.

Prophylactic application of closed-incision NPWT in aseptic surgery - a review of literature.

Negative pressure wound therapy is a generally accepted method of treating septic or secreting wounds. In contrast to that, postoperative application of negative pressure wound therapy to primarily closed surgical wounds is referred to as closed-incision negative-pressure wound therapy (Ci-NPWT). According to available sources, wounds after prophylactic application of Ci-NPWT show lower complication rates, especially wound infections, and dehiscence. The literature confirms that the Ci-NPWT technique improves healing of all surgical wounds, both septic and aseptic.

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.

The effects of negative pressure wound therapy on wounds with cerebrospinal fluid leakages.

OBJECTIVE: Negative pressure wound therapy (NPWT) has been widely used for a variety of wounds with good outcomes. However, it is contraindicated in the management of wounds with cerebrospinal fluid (CSF) leakages. The reason is the fear of a sudden shift of CSF fluid as a result of suction leading to brain herniation or coning. There is a paucity of data to either support or negate such claims. We aimed to determine the effect of NPWT in the management of patients with wounds with CSF leakages. METHOD: This was a longitudinal prospective study of patients having wounds with CSF leakages managed with NPWT in our institute. Outcome measures evaluated were changes in the level of consciousness, Glasgow Coma Scale (GCS) score, length of hospital stay, mean effluent collected, time taken for the wounds to heal/close and complications related to NPWT. RESULTS: A total of 12 patients with wounds that had CSF leakage were managed with NPWT over two years. Of the patients, nine had wounds in communication with the brain, with three patients having spinal cord wounds. The average effluent collected on the first day of applying NPWT was 510ml, and by the third day this had fallen to approximately 200ml. The mean time taken for wounds to close was 12.3 days. There was no evidence of herniation nor any other morbidities or mortalities reported in any of our patients. CONCLUSION: NPWT, as indicated in this series, had a beneficial effect in the management of wounds with CSF leakage. NPWT, once applied to the wound, caused a tamponade effect that resulted in stoppage of the leakage of the CSF and did not lead to suction of the fluid, as previously thought. The dressings ensured an airtight system, preventing communication between the wound and the external environment, thus reducing sepsis while awaiting definitive wound closure.

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.

Safety and efficacy of negative pressure wound therapy in treating deep surgical site infection after lumbar surgery.

PURPOSE: To evaluate the efficacy and safety of negative pressure wound therapy (NPWT) for post-operative deep surgical site infection (SSI) after posterior instrumented spinal surgery. METHODS: We retrospectively compared the clinical outcomes of NPWT with standard debridement for deep SSI after posterior instrumented spinal surgery from 2012 to 2020 in our department. The primary outcomes were peri-operative characteristics including positive organism results, duration of fever, and visual analogue scale (VAS) pain scores three days after re-operation. The secondary outcomes were post-operative characteristics including implant infection recurrence, implant retention rate, duration of hospitalization, and VAS at discharge. Pearson's chi-squared analysis (categorical) and Student's t test (continuous) were used to determine the differences. RESULTS: Thirty-four patients were included, of which 19 underwent NPWT, and 15 underwent standard debridement. Patients in the NPWT group all significantly improved primary outcomes including duration of fever after re-operation (0.95 ± 1.13 vs 4.07 ± 5.35, P = 0.001), positive organism results (14 of 19 vs 2 of 15, P < 0.01), and VAS at 3 days after re-operation (2.58 ± 0.69 vs 3.40 ± 1.06, P < 0.05). Patients in NPWT group exhibited significant decrease in implant infection recurrence (0 of 19 vs 5 of 15, P < 0.01), implant retention rate (19 of 19 vs 10 of 15, P < 0.01), duration of hospitalization (27.74 ± 10.95 vs 37.67 ± 13.67, P < 0.01). CONCLUSIONS: NPWT is a feasible and safe treatment option for deep SSI after posterior instrumented spinal surgery.