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.

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.

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.

A Pilot Study of Negative Pressure Therapy with Autologous Skin Cell Suspensions in a Porcine Model.

BACKGROUND: Negative pressure wound therapy (NPWT) is an option for securing meshed split thickness skin grafts (mSTSGs) after burn excision to optimize skin graft adherence. Recently, the use of autologous skin cell suspension (ASCS) has been approved for use in the treatment of burn injuries in conjunction with mSTSGs.To date, limited data exists regarding the impact of NPWT on healing outcomes when the cellular suspension is utilized. It was hypothesized that NPWT would not negatively impact wound healing of ASCS+mSTSG. MATERIALS AND METHODS: A burn, excision, mSTSG, ASCS ± NPWT model was used. Two Duroc pigs were utilized in this experiment, each with 2 sets of paired burns. Four wounds received mSTSG+ASCS+NPWT through post-operative day 3, and 4 wounds received mSTSG+ACSC+ traditional ASCS dressings. Cellular viability was characterized prior to spraying. Percent re-epithelialization, graft-adherence, pigmentation, elasticity, and blood perfusion and blood vessel density were assessed at multiple time points through 2 weeks. RESULTS: All wounds healed within 14 days with minimal scar pathology and no significant differences in percent re-epithelialization between NPWT, and non-NPWT wounds were observed. Additionally, no differences were detected for pigmentation, perfusion, or blood vessel density. NPWT treated wounds had less graft loss and improved elasticity, with elasticity being statistically different. CONCLUSIONS: These data suggest the positive attributes of the cellular suspension delivered are retained following the application of negative pressure. Re-epithelialization, revascularization, and repigmentation are not adversely impacted. The use of NPWT may be considered as an option when using ASCS with mSTSGs for the treatment of full-thickness burns.

Securing split-thickness skin grafts using negative-pressure wound therapy without suture fixation.

OBJECTIVE: Negative-pressure wound therapy (NPWT) is generally applied as a bolster for split-thickness skin grafts (STSG) after the graft has been secured with sutures or skin staples. In this study, NPWT was applied to secure STSGs without any sutures or staples. Surgical outcomes of using NPWT without sutures was compared with a control group. METHODS: Patients with STSGs were divided into two groups: a 'no suture' group using only NPWT, and a control group using conventional fixings. In the no suture group, the grafts were covered with meshed wound dressing and ointment. The NPWT foam was placed over the STSG and negative pressure applied. In the control group, grafts were fixed in place using tie-over bolster, securing with fibrin glue, or NPWT after sutures. RESULTS: A total of 30 patients with 35 graft sites participated in the study. The mean rate of graft take in the no suture group was 95.1%, compared with 93.3% in the control group, with no significant difference between them. No graft shearing occurred in the no suture group. Although the difference did not reach statistical significance, mean surgical time in the no suture group (31.5 minutes) tended to be shorter than that in the control group (55.7 minutes). CONCLUSION: By eliminating sutures, the operation time tended to be shorter, suturing was avoided and suture removal was not required meaning that patients could avoid the pain associated with this procedure. Furthermore, the potential for staple retention and its associated complications was avoided, making this method potentially beneficial for both medical staff and patients.

Evaluation of closed incision negative pressure therapy systems on the closure of incisional space model.

OBJECTIVE: The objective of this study was to compare the ability of foam dressing-based and non-foam-based closed incision negative pressure therapy (ciNPT) systems to close isolated incisional deficits in a tissue model. METHODS: Similarly sized foam-based and non-foam-based absorbent ciNPT dressings were applied to ~36cm long, ~3mm and ~6mm wide simulated incisions in gel sheets covered with drape (n=6 dressings/group/experimental condition spread over three respective therapy units). Changes in incision widths were measured directly or with overlying solid gel sheeting (to mimic tissue resistance), at five equally spaced locations before, immediately upon and one hour after initiating negative pressure using associated therapy units. RESULTS: Foam-based ciNPT closed simulated incisions more often than non-foam-based ciNPT in all tested conditions (p<0.05). While foam-based ciNPT almost completely closed the ~3mm wide incisional spaces, unlike non-foam-based ciNPT, the biggest differences between the two groups were observed with the ~6mm incisional width, which allowed maximal inward-stretching of the appositional faces without complete closure. The additional gel layer blunted closure in both groups, but much more with non-foam-based ciNPT. There was minimal impact of negative pressure duration on these results. CONCLUSION: Foam-based ciNPT closed incisional widths in simulated tissue significantly more compared with non-foam-based ciNPT. Different ciNPT systems should not be considered necessarily equivalent in performance.

Can systemically administered antibiotics be detected in wound tissues and surfaces under negative pressure wound therapy?

In this study, we evaluated a new aspect of negative pressure wound therapy (NPWT) as an analytical tool for pharmacokinetic studies. Twenty-one patients with soft tissue defects scheduled to receive NPWT were included in this study. Concomitant to NPWT, all patients received intravenous moxifloxacin (MX). At different time intervals, blood plasma levels of MX were sampled and compared with synchronous concentrations of MX in the exudate obtained from the NPWT drainage system. Serial measurements were performed upon initiation of the therapy as well as in the steady state (after 5 days). At steady state, wound tissue was obtained intraoperatively. High-performance liquid-chromatography (HPLC) was used for analysis. At 1 hour post-administration, the exudate/plasma levels (mg/L) were 1.92/3.07; at 12 hours, 0.80/1.14; at 24 hours, 0.26/0.43; and at 120 hours (steady state), 0.42/0.47. There was a correlation between exudate and plasma levels reaching approximately 0.75. Until now, methods for pharmacokinetic studies concerning interstitial fluid are difficult to apply in the clinical context. The presented method showed limitations, but we believe that, after methodological improvements, measurements of substances in the interstitial fluid by means of NPWT are feasible.

Bacterial reduction and shift with NPWT after surgical debridements: a retrospective cohort study.

BACKGROUND: Surgical debridement, negative-pressure wound therapy (NPWT) and antibiotics are used for the treatment of open wounds. However, it remains unclear whether this treatment regimen is successful in the reduction and shift of the bacterial load. METHODS: After debridement in the operating room, NPWT, and antibiotic treatment, primary and secondary consecutive microbiological samples of 115 patients with 120 open wounds with bacterial or yeast growth in ≥1 swab or tissue microbiological sample(s) were compared for bacterial growth, Gram staining and oxygen use at a level one trauma center in 2011. RESULTS: Secondary samples had significantly less bacterial growth (32 vs. 89%, p < .001, OR 17), Gram-positive bacteria (56 vs. 78%, p = .013), facultative anaerobic bacteria (64 vs. 85%, p = .011) and Staphylococcus aureus (10 vs. 46%, p = .002). They also tended to include relatively more Coagulase-negative Staphylococci (CoNS) (44 vs. 18%) and Pseudomonas species (spp.) (31 vs. 7%). Most (98%) wounds were successfully closed within 11 days, while wound revision was needed in 4%. CONCLUSIONS: The treatment regimen of combined use of repetitive debridement, irrigation and NPWT in an operating room with antibiotics significantly reduced the bacterial load and led to a shift away from Gram-positive bacteria, facultative anaerobic bacteria, and S. aureus, as well as questionably toward CoNS and Pseudomonas spp. in this patient cohort. High rates of wound closure were achieved in a relatively short time with low revision rates. Whether each modality played a role for these findings remains unknown.

Classification, prevention and management of entero-atmospheric fistula: a state-of-the-art review.

BACKGROUND: Entero-atmospheric fistula (EAF) is an enteric fistula occurring in the setting of an open abdomen, thus creating a communication between the GI tract and the external atmosphere. Management and nursing of patients suffering EAF carries several challenges, and prevention of EAF should be the first and best treatment option. PURPOSE: Here, we present a novel modified classification of EAF and review the current state of the art in its prevention and management including nutritional issues and feeding strategies. We also provide an overview on surgical management principles, highlighting several surgical techniques for dealing with EAF that have been reported in the literature throughout the years. CONCLUSIONS: The treatment strategy for EAF should be multidisciplinary and multifaceted. Surgical treatment is most often multistep and should be tailored to the single patient, based on the type and characteristics of the EAF, following its correct identification and classification. The specific experience of surgeons and nursing staff in the management of EAF could be enhanced, applying distinct simulation-based ex vivo training models.

A New Method of Salvaging Breast Reconstruction After Breast Implant Using Negative Pressure Wound Therapy and Instillation.

UNLABELLED: Breast implant infections and their associated inflammatory response can have severe consequences, such as the loss of the prosthesis and cavity, or extensive scarring. Negative pressure wound therapy has been indicated for the management of implant infections. This report describes situations where negative pressure wound therapy was used in conjunction with instillation therapy to treat breast implant infections. The findings showed that the application of these techniques accelerated the treatment of the infections and, most importantly, maintained the breast cavity for future reconstruction. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Evaluating a novel vertical traction device for early closure in open abdomen management: a consecutive case series.

Background: In emergency surgery, managing abdominal sepsis and critically ill patients with imminent abdominal compartment syndrome (ACS) using an open abdomen (OA) approach has become standard practice for damage control. To prevent significant complications associated with OA therapy, such as abdominal infections, entero-atmospheric fistula (EAF), and abdominal wall hernia formation, early definitive fascial closure (DFC) is crucial. This study aims to assess the feasibility of a novel device designed to facilitate early fascial closure in patients with an open abdomen. Methods: Between 2019 and 2020, nine patients undergoing open abdomen management were enrolled in this study. All patients were treated using vertical mesh-mediated fascial traction combined with a novel vertical traction device (VTD). Data from these cases were collected and retrospectively analyzed. Results: In this study, all patients were treated with OA due to impending ACS. Three patients died before achieving DFC, while the remaining six patients successfully underwent DFC. The mean number of surgical procedures after OA was 3 ± 1, and the mean time to DFC was 9 ± 3 days. The use of the VTD in combination with negative pressure wound therapy (NPWT) resulted in a 76% reduction in fascia-to-fascia distance until DFC was achieved. The application of the VTD did not affect ventilation parameters or the Simplified Acute Physiology Score II (SAPS II), but intra-abdominal pressure (IAP) was reduced from 31 ± 8 mmHg prior to OA to 8.5 ± 2 mmHg after applying the device. The primary complication associated with the device was skin irritation, with three patients developing skin blisters as the most severe manifestation. Conclusion: Overall, the novel VTD appears to be a safe and feasible option for managing OA cases. It may reduce complications associated with OA by promoting early definitive fascial closure.

A case series of prophylactic negative pressure wound therapy use with purse-string closure in stoma closure wounds in infants.

BACKGROUND: The study introduces the application of negative pressure wound therapy (NPWT) in pediatric stoma closure, emphasizing the importance of enhancing aesthetics and minimizing surgical site infections (SSI). CASE PRESENTATION: The case series involves four infants undergoing non-umbilical stoma closure with a combination of purse-string closure (PSC) and NPWT, focusing on aesthetic outcomes and infection prevention. NPWT was initiated immediately after surgery, and patients were monitored every 3-4 days. Notably, none of the four infants experienced SSI or other complications. The patients adequately tolerated NPWT, with no significant adverse events. Furthermore, Manchester Scar Scale (MSS) was 9 [7-10], and Patient and Observer Scar Assessment Scale (POSAS) (observer) was 12.5 [12-19], POSAS (patient) was 12.5 [11-16] (all median values [minimum-maximum]), indicating that excellent aesthetic outcomes were achieved. DISCUSSION: We emphasizes the significance of aesthetics in pediatric patients; in addition, our findings demonstrate that four infants who received NPWT combined with PSC achieved superior outcomes that did the most recent four infants who underwent PSC only at our institution. It also addresses the risk of SSI in stoma closure and discusses the pros and potential cons of using NPWT in pediatric cases, underlining the need for further research and the accumulation of additional reports. CONCLUSIONS: This is the inaugural report of prophylactic NPWT for pediatric stoma closure, emphasizing the effectiveness of combining PSC and NPWT for SSI prevention and improved aesthetics. The study calls for additional research and reports on NPWT in pediatric cases to further solidify its benefits in this patient population.

A Comparison of Negative Pressure and Conventional Therapy in Spine Infections: A Single-Center Retrospective Study.

Purpose: To investigate the effectiveness and safety of negative-pressure wound therapy (NPWT) in treating primary spinal infections. Methods: Patients who underwent surgical treatment for primary spinal infection between January 2018 and June 2021 were retrospectively evaluated. They were divided into two groups based on the type of surgery: one that underwent negative-pressure wound therapy (NPWT) and another that underwent conventional surgery (CVSG-Posterior debridement, bone grafting, fusion, and internal fixation in one stage). The two groups were compared in terms of the total operation time, total blood loss, total postoperative drainage, postoperative pain score, time for the postoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to return to normal, postoperative complications, treatment time, and recurrence rate. Results: A total of 43 cases of spinal infection were evaluated, with 19 in the NPWT group and 24 in the CVSG group. The NPWT group had a superior postoperative drainage volume, antibiotic use time, erythrocyte sedimentation rate and CRP recovery times, VAS score at 3 months after the operation, and cure rate at 3 months after operation compared with the CVSG group. There were no significant variations in the total hospital stay and intraoperative blood loss between the two groups. Conclusions: This study supports the use of negative pressure in the treatment of a primary spinal infection and indicates that it has a notably better short-term clinical effect than conventional surgery. Additionally, its mid-term cure rate and recurrence rate are more desirable than those of conventional treatments.

Treatment of Fournier's gangrene with negative pressure wound therapy in the course of sepsis - Case report.

INTRODUCTION: Fournier's Gangrene is a severe and rapidly progressing necrotic infection of the skin and fascia that can affect the external genitals, perineum, anus, and abdomen. It can extend to the abdominal cavity and result in necrosis of the soft tissue with a high mortality rate. This case gives a unique perspective on managing such a complicated infection in a smaller community hospital. PRESENTATION OF CASE: This report describes a particularly challenging case of Fournier's Gangrene in a 34 year old male with multiple pre-existing comorbidities, including alcohol use disorder, chronic kidney disease, and hepatitis B. Development of gangrene was preceded by sepsis. The patient's treatment was based on intravenous antibiotic therapy and early surgical intervention with extensive resection of necrotic tissue, supported by Hyperbaric Oxygen Therapy (HBOT) and Negative Pressure Wound Therapy (NPWT). DISCUSSION: The majority of the patient's treatment was done at a local community hospital with remote coordination with the Hyperbaric Medicine Center where the patient was temporarily transferred to for HBOT. Multiple treatment modalities were employed in this case of Fournier's gangrene, including intravenous antibiotic therapy, necrosectomy, chronic wound care with septic dressings and tissue debridement, HBOT and NPWT. Interdisciplinary cooperation between different medical specialists was crucial in treatment. CONCLUSION: The presented case shows that despite the large scale of difficulty and the complexity of treatment, it is possible to effectively manage Fournier's Gangrene in a local community hospital through interdisciplinary cooperation with specialized quaternary care centers. HBOT and NPWT proved to be useful treatment modalities.

Case Report: A spinal infection with bilateral psoas abscesses was treated with NPWT to enhance the local infection by increasing the infiltration of neutrophil cells and draining the pus.

Treatment of spinal brucellosis with bilateral psoas abscess is a challenging clinical endeavor. We retrospectively evaluated a case of lumbar infection and bilateral psoas abscess, and was effectively managed through a unilateral extreme lateral approach with the aid of NPWT for bilateral drainage. We hypothesize that NPWT can influence the Piezo1 receptor of neutrophils and further influence the interaction between neutrophils and endothelial cells to promote the clearance of infected lesions, and this phenomenon is also observed in pathological slides. This proves that NPWT can rapidly enhance the recruitment of neutrophils in the infected area and improve the local immune response, and after a year of reassessment and tracking, Bilateral drainage using NPWT via a unilateral Extreme Lateral Approach could acquire satisfactory surgical outcomes, can be used as a treatment modality for lumbar infection with bilateral psoas abscesses.

Combined computational analysis and cytology show limited depth osteogenic effect on bone defects in negative pressure wound therapy.

Background: The treatment of bone defects remains a clinical challenge. The effect of negative pressure wound therapy (NPWT) on osteogenesis in bone defects has been recognized; however, bone marrow fluid dynamics under negative pressure (NP) remain unknown. In this study, we aimed to examine the marrow fluid mechanics within trabeculae by computational fluid dynamics (CFD), and to verify osteogenic gene expression, osteogenic differentiation to investigate the osteogenic depth under NP. Methods: The human femoral head is scanned using micro-CT to segment the volume of interest (VOI) trabeculae. The VOI trabeculae CFD model simulating the bone marrow cavity is developed by combining the Hypermesh and ANSYS software. The effect of trabecular anisotropy is investigated, and bone regeneration effects are simulated under NP scales of -80, -120, -160, and -200 mmHg. The working distance (WD) is proposed to describe the suction depth of the NP. Finally, gene sequence analysis, cytological experiments including bone mesenchymal stem cells (BMSCs) proliferation and osteogenic differentiation are conducted after the BMSCs are cultured under the same NP scale. Results: The pressure, shear stress on trabeculae, and marrow fluid velocity decrease exponentially with an increase in WD. The hydromechanics of fluid at any WD inside the marrow cavity can be theoretically quantified. The NP scale significantly affects the fluid properties, especially those fluid close to the NP source; however, the effect of the NP scale become marginal as WD deepens. Anisotropy of trabecular structure coupled with the anisotropic hydrodynamic behavior of bone marrow; An NP of -120 mmHg demonstrates the majority of bone formation-related genes, as well as the most effective proliferation and osteogenic differentiation of BMSCs compared to the other NP scales. Conclusion: An NP of -120 mmHg may have the optimal activated ability to promote osteogenesis, but the effective WD may be limited to a certain depth. These findings help improve the understanding of fluid mechanisms behind NPWT in treating bone defects.

Split thickness skin graft compression: a scoping review.

Background: Split thickness skin graft (STSG) is a routine reconstructive manoeuvre, particularly after excision of cutaneous lower limb malignancies. While surgical technique is well established, evidence supporting the postoperative management of these grafts is less robust. Compression therapy after the index procedure may be an important adjunct for graft take and minimizing complications, particularly in patients susceptible to oedema from a concurrent lymph node procedure. Methods: An initial PubMed literature search was performed using the terms "split thickness skin graft", "compression" and "oedema" yielding no results, hence a broader search was performed combining the terms "compression", "pressure" and "split thickness skin graft" providing 383 results. One hundred articles remained for abstract review after an initial screen. Results: The literature on compression therapy to promote split thickness graft take is modest, with only 12 articles described (12/100, 12.0%). Even then, none of these were in the setting of grafting after oncological resection. Many of the articles promote negative pressure wound therapy (NPWT) as an established adjunct to promote graft take (80/100, 80.0%). Conclusions: There is limited demonstrated efficacy of postoperative compression therapy for lower limb STSG let alone in patients with an ancillary lymph node procedure. Further large-scale trials ideally in a prospective fashion are warranted to validate this as a simple, widely available and cost-effective adjunct to STSG in this particularly susceptible population of reconstructive patients.

Successful pedicled vertical rectus abdominis myocutaneous flap reconstruction with negative-pressure wound therapy for deep sternal wound infection: a case report and comprehensive review.

Introduction: Deep sternal wound infection (DSWI) is a serious complication that may occur after median sternotomy, with potentially devastating consequences. By reporting our case and analyzing the existing literature, this article aimed to provide a thorough understanding of the role of negative-pressure wound therapy (NPWT) and the importance of flap choice in managing DSWI accompanied by severe heart injury and high hemodynamic risk. Case description: A 60-year-old woman with severe aortic stenosis, aortic valve regurgitation, and heart failure underwent redo sternotomy, which resulted in an intraoperative right ventricle injury. She required extracorporeal membrane oxygenation support because of low blood pressure and subsequently developed complications, including surgical site hematoma, wound dehiscence, and fat necrosis. She was referred for wound closure, where a significant 10 × 20-cm soft tissue defect in the anterior chest wall was observed. A pedicled vertical rectus abdominis myocutaneous flap addressed the soft tissue defect. The wound showed remarkable improvement at the 8-month follow-up visit. Conclusions: DSWI management is a complex and multifaceted challenge. NPWT, when combined with appropriate surgical strategies, including wound debridement and flap selection, may promote successful wound healing. This case report highlights the successful management of a complex DSWI using a multidisciplinary approach, including debridement, appropriate antibiotic therapy, and free-flap reconstruction, which resulted in favorable outcomes.

Negative Pressure Wound Therapy for the Treatment of Fournier's Gangrene: A Rare Case with Rectal Fistula and Systematic Review of the Literature.

Fournier's gangrene (FG) is a Necrotizing Soft Tissue Infection (NSTI) of the perineal region characterized by high morbidity and mortality even if appropriately treated. The main treatment strategies are surgical debridement, broad-spectrum antibiotics, hyperbaric oxygen therapy, NPWT (Negative Pressure Wound Therapy), and plastic surgery reconstruction. We present the case of a 50-year-old woman with an NSTI of the abdomen, pelvis, and perineal region associated with a rectal fistula referred to our department. After surgical debridement and a diverting blow-out colostomy, an NPWT system composed of two sponges connected by a bridge through a rectal fistula was performed. Our target was to obtain healing in a lateral-to-medial direction instead of depth-to-surface to prevent the enlargement of the rectal fistula, promoting granulation tissue growth towards the rectum. This eso-endo-NPWT technique allowed for the primary suture of the perineal wounds bilaterally, simultaneously treating the rectal fistula and the perineum lesions. A systematic review of the literature underlines the spreading of NPWT and its effects.

Superior Enhancement of Cutaneous Microcirculation Due to "Cyclic" Application of a Negative Pressure Wound Therapy Device in Humans - Local and Remote Effects.

Objectives: Despite a common utilization of "Negative Pressure Wound Therapy" (NPWT) Devices in a wide range of specialties, some of the basic mechanisms of action of the techniques are still on debate. Conflicting results from prior studies demonstrate our lack of understanding how wound-bed perfusion or cutaneous microcirculation is affected by NPWT. Methods: We conducted a prospective randomized study which included 45 healthy subjects to further investigate the acute effects of NPWT on cutaneous microcirculation underneath the applied dressing. Three modes of application, namely, continuous, intermittent, cyclic, were tested. Amongst others, measurements of elicited surface pressure and a comprehensive microcirculatory analysis were carried out by utilizing an O2C-device. For the detection of (systemic) remote effects, perfusion changes of the contra-lateral thigh were evaluated. Results: All three tested modes of application led to a significant (p < 0.05) improvement in local tissue perfusion with an increased blood flow of max +151% and tissue oxygen saturation of +28.2% compared to baseline values. Surface pressure under the dressing significantly increased up to 29.29 mmHg due to the activation of the NPWT device. Continuous, intermittent, and cyclic application of negative pressure were accurately sensed by participants, resulting in reported pain values that mirrored the different levels of applied suction. Although the cyclic application mode showed the most pronounced effects regarding microcirculatory changes, no statistical significance between groups was observed. Conclusion: We could demonstrate a significant improvement of cutaneous microcirculation under an applied NPWT dressing with favorable effects due to cyclic mode of application. An increased surface pressure leads to a better venous drainage of the tissue, which was shown to increase arterial inflow with a consecutive improvement of oxygen supply. Further research is warranted to evaluate our findings regarding wound bed perfusion in the clinical field with respect to formation of granulation tissue and wound healing.