Negative Pressure Wound Therapy Group Research Articles

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

This study aims to evaluate the benefits of treating diabetic foot ulcers (DFU) through a revised procedure using the mechanisms underlying negative pressure wound therapy (NPWT) in such a way as to achieve reduced and more evenly distributed lateral tension lines across the wound. Patients with type 2 diabetes were assessed for elegibility. Included patients were divided randomly into two groups: the NPWT control group and the NPWT+ group. Patients in the NPWT control group were treated in the traditional manner: wounds were covered with foams shaped to fit the wound precisely. In the NPWT+ group, foams were shaped to fit the wound precisely, and an additional foam was then wrapped around the foot. Some 85 patients were assessed for eligibility; 59 were randomised into two groups: 29 patients in the NPWT+ group and 30 patients in the NPWT group. The primary objective was median healing time (NPWT+ 19 days, interquartile ratio (IQR) 7.5; NPWT 33 days, IQR 16; p<0.00001), and complete wound healing at three weeks (NPWT+ 55.20% NPWT 26.70% p=0.02). Secondary endpoints included number of major amputations (none in either group) and number of infections (NPWT+ 3.44% of patients, NPWT 6.66% of patients; p=0.57). Our initial findings show that this treatment significantly reduced wound closure times and accelerated healing in DFUs. It also demonstrated promising improvements in healing rates, with no significant increase in wound complications.

Surgical wound infection prevention using topical negative pressure therapy on closed abdominal incisions – the ‘SWIPE IT’ randomized clinical trial

Surgical site infections (SSIs) are the most common cause of healthcare-associated infections in surgical patients. It is unclear whether incisional negative pressure wound therapy (NPWT) can reduce the risk of SSIs in patients after open abdominal surgery. A prospective, non-blinded multi-centre randomized controlled trial (RCT) was performed to evaluate the incidence of SSI post-laparotomy using incisional NPWT compared with a standard dressing. The primary outcome was the rate of superficial SSI. A total of 124 patients (61 patients in the NPWT arm and 63 patients in the control arm) were included. One hundred and nine (87.9%) patients underwent colorectal surgery; 61 patients (49.2%) had emergency surgery. There were more superficial SSIs in the control group than in the NPWT group, although not statistically significant (20.6% vs 9.8%, P=0.1). Upon multiple logistic regression analysis, control dressings were associated with increased risk of superficial SSI although again, not statistically significant (odds ratio (OR) 2.41, 95% confidence interval (CI) 0.81-7.17, P=0.11). There was no superficial non-SSI related wound dehiscence in the NPWT group compared with 9.5% in the control group (P=0.03). There was no difference in postoperative complications (P=0.15), nor in other wound complications (P=0.79). NPWT was not associated with decreased superficial SSI in this RCT. However, there was a statistically significant reduction in superficial wound dehiscence with NWPT dressings. The results of this study should be included in meta-analyses for better evaluation of NPWT on closed abdominal incisions.

Negative pressure wound therapy for skin necrosis prevention after snakebite in the emergency department: A retrospective cohort study.

This retrospective cohort study aimed to compare the effectiveness of conventional treatment and ultra-early application of negative pressure wound therapy (NPWT) in patients with snakebites.Patients who visited the emergency department within 24 hours after a snakebite were assigned to the non- NPWT or NPWT group. Swelling resolution time and rates of necrosis, infection, and operations were compared between the 2 groups. The Stony Brook Scar Evaluation Scale was used to measure short- and long-term wound healing results.Among the included 61 patients, the swelling resolution time was significantly shorter in the NPWT group than in non- NPWT group (P = .010). The NPWT group showed lower necrosis (4.3% versus 36.8%; P = .003) and infection (13.2% and 4.3%; P = .258) rates than the non- NPWT group. The median Stony Brook Scar Evaluation Scale scores were higher in the NPWT group than in the non- NPWT group (P< .001).These findings suggest that ultra-early application of NPWT reduces edema, promotes wound healing, and prevents necrosis in patients with snakebites.

Prophylactic Negative Pressure Wound Therapy After Laparotomy for Gynecologic Surgery: A Randomized Controlled Trial.

To estimate the effectiveness of prophylactic negative pressure wound therapy in patients undergoing laparotomy for gynecologic surgery. We conducted a randomized controlled trial. Eligible, consenting patients, regardless of body mass index (BMI), who were undergoing laparotomy for presumed gynecologic malignancy were randomly allocated to standard gauze or negative pressure wound therapy. Patients with BMIs of 40 or greater and benign disease also were eligible. Randomization, stratified by BMI, occurred after skin closure. The primary outcome was wound complication within 30 (±5) days of surgery. A sample size of 343 per group (N=686) was planned. From March 1, 2016, to August 20, 2019, we identified 663 potential patients; 289 were randomized to negative pressure wound therapy (254 evaluable participants) and 294 to standard gauze (251 evaluable participants), for a total of 505 evaluable patients. The median age of the entire cohort was 61 years (range 20-87). Four hundred ninety-five patients (98%) underwent laparotomy for malignancy. The trial was eventually stopped for futility after an interim analysis of 444 patients. The rate of wound complications was 17.3% in the negative pressure wound therapy (NPWT) group and 16.3% in the gauze group, absolute risk difference 1% (90% CI -4.5 to 6.5%; P=.77). Adjusted odds ratio controlling for estimated blood loss and diabetes was 0.99 (90% CI 0.62-1.60). Skin blistering occurred in 33 patients (13%) in the NPWT group and in three patients (1.2%) in the gauze group (P<.001). Negative pressure wound therapy after laparotomy for gynecologic surgery did not lower the wound complication rate but did increase skin blistering. ClinicalTrials.gov, NCT02682316. The protocol was supported in part by KCI/Acelity.

Combining Negative Pressure Wound Therapy with Insulin Instillation Reduces Insulin Resistance and Accelerates Healing in Patients with Chronically Infected Wounds

This study aimed at evaluating the effects of negative pressure wound therapy (NPWT) combined with insulin instillation on wound healing and insulin resistance (IR) in patients with chronically infected wounds.

Clinical outcome and cost analysis of negative pressure wound therapy in extremity wounds: a comparison to conventional wound management

&lt;p&gt;&lt;strong&gt;Background:&lt;/strong&gt; Open fractures and traumatic wounds constitute a major health problem. Amongst the armamentarium of wound care products available, negative pressure wound therapy (NPWT) is a modality that has transformed wound care and has been recommended for treating all kinds of acute and chronic wounds.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods:&lt;/strong&gt; This prospective randomised comparative study was conducted at a tertiary care hospital in Northeast India. 30 patients were included in this study over a period of 24 months commencing from January 2018. The patients consisted of two groups of 15 each, the first group comprised patients who underwent treatment using NPWT and the second group was treated using standard wound therapy (SWT). The endpoint taken was a granulated wound or a wound ready for split skin grafting (SSG).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; The mean wound size difference between the NPWT group and the SWT group on day nine was 13±7.17 mm and 4.53±0.99 mm, respectively. Likewise, on day nine, 11 (73.3%) patients in the group treated using NPWT had no positive bacterial cultures compared to 8(53.3%) patients on SWT. The estimated cost of materials for each NPWT dressing change was roughly INR₹ 3446 (US$ 45.57).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; NPWT is not a magic bullet and will not replace the basic methods of wound treatment such as wound debridement, infection control and ensuring adequate blood supply. Nevertheless, NPWT remains an integral part of the current scenario in wound care management and is cost effective under the condition that it accelerates wound healing when compared to traditional treatment.&lt;/p&gt;

Negative pressure wound therapy for prevention of surgical site infection in patients at high risk after clean-contaminated major pancreatic resections: A single-center, phase 3, randomized clinical trial

BackgroundSurgical site infections are an important burden of pancreatic surgery, prolonging hospitalization and delaying adjuvant treatment. The aim of this study was to compare negative pressure wound therapy with standard sterile dressing in terms of the prevention of non–organ-space surgical site infection (superficial and deep surgical site infection) in the high-risk setting. MethodsThe trial was conducted at the University of Verona Hospital Trust, Verona, Italy, from July 25, 2018, through October 10, 2019, among adults undergoing surgery for periampullary neoplasms. Only patients at high-risk for surgical site infection based on body mass index, diabetes, steroids, neoadjuvant therapy, American Society of Anesthesiologists score, Charlson comorbidity index, duration of surgery, and blood loss were included and randomized. ResultsA total of 351 patients were screened, 100 met the inclusion criteria and were 1:1 allocated in the 2 arms. The difference in terms of non–organ-space surgical site infection comparing negative pressure wound therapy with standard sterile dressing was not significant (10.9 vs 12.2%, risk ratio [RR] 1.144, confidence interval [CI] 95% 0.324–4.040, P = 1.000). Hematomas (4.3 vs 2%, RR 1.565, CI 95% 0.312–7.848, P = .609) and organ-space infections (46.7 vs 43.8%, RR 1.059, CI 95% 0.711–1.576, P = .836) were similar. Negative pressure wound therapy prevented the development of seromas (0 vs 12.2%, RR 0.483, CI 95% 0.390–0.599, P = .027). The aesthetic result assessed on postoperative day 7 was better in the negative pressure wound therapy group (visual analogue scale, 8 vs 7, P = .029; Stony Brook Scar Evaluation Scale, 3.2 vs 2.5, P = .009), but it was no more evident on postoperative day 30 after a total number of 23 dropouts. ConclusionCompared with standard sterile dressing, negative pressure wound therapy is not associated with an improved rate of non–organ-space surgical site infection after surgery for periampullary neoplasms in patients at high risk for surgical site infection. Additional studies will help identify the population that could benefit most from this intervention.

Negative pressure wound therapy for burn patients: A meta-analysis and systematic review.

Negative pressure wound therapy (NPWT), which has been applied in various medical specialties to accelerate wound healing, has been the object of a few investigations. We explored the effectiveness of NPWT and the possibility of its inclusion in burn management guidelines. Randomised controlled trials comparing NPWT with non‐NPWT treatments for burn wounds were extracted from PubMed. For the risk of bias analysis, all included studies were evaluated according to the Cochrane risk of bias tool and the approaches outlined in the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) Handbook. Outcomes such as graft take rate in the first week, infection rate, and overall complication rate were analysed. Six studies that included a total of 701 patients met our inclusion criteria. Qualitative analysis revealed that the NPWT group had a significantly better overall graft rate in the first week (P = 0.001) and a significantly lower infection rate (P = 0.04). No significant difference in the overall complication rate was found. Our results indicate that NPWT is a safe method for stimulating healing and lowering the infection rate of burn wounds. NPWT can be part of general burn management, and its incorporation into burn treatment guidelines is recommended.

Prophylactic negative-pressure wound therapy after ileostomy reversal for the prevention of wound healing complications in colorectal cancer patients: a randomized controlled trial

BackgroundThe aim of this study was to assess the usefulness of protective negative-pressure wound therapy (NPWT) in the reduction of wound healing complications (WHC) and surgical site infections (SSI) after diverting ileostomy closure in patients who underwent surgery for colorectal cancer.MethodsIn this prospective randomized clinical trial in a tertiary academic surgical center, patients who had colorectal cancer surgery with protective loop ileostomy and were scheduled to undergo ileostomy closure with primary wound closure from January 2016 to December 2018 were randomized to be treated with or without NPWT. The primary endpoint was the incidence of WHC. Secondary endpoints were incidence of SSI, length of postoperative hospital stay (LOS), and length of complete wound healing (CWH) time.ResultsWe enrolled 35 patients NPWT (24 males [68.6%]; mean age 61.6 ± 11.3 years), with NPWT and 36 patients (20 males [55.6%]; mean age 62.4 ± 11.3 years) with only primary wound closure (control group). WHC was observed in 11 patients (30.6%) in the control group and 3 (8.57%) in the NPWT group (p = 0.020). Patients in the NPWT group had a significantly lower incidence of SSI (2 [5.71%] vs. 8 [22.2%] in the control group; p = 0.046) as well as significantly shorter median CWH (7 [7–7] days vs. 7 [7–15.5] days, p = 0.030). There was no difference in median LOS between groups (3 [2.5–5] days in the control group vs. 4 [2–4] days in the NPWT group; p = 0.072).ConclusionsProphylactic postoperative NPWT after diverting ileostomy closure in colorectal cancer patients reduces the incidence of WRC and SSI.Clinical trial registrationclinicaltrials.gov (NCT04088162).

Negative-pressure wound therapy for III/IV pressure injuries: A meta-analysis.

This meta-analysis was conducted to identify the potential benefits and the efficacy of negative-pressure wound therapy (NPWT) for III/IV pressure injuries (PIs) compared with standard wound care (SWC). Sixteen RCTs with 629 patients were included in our analysis. The methodological quality was assessed by the Cochrane Collaboration Tool. The outcomes included complete ulcer healing rate, wound healing time, pain score, the frequency of dressing change, hospitalization cost, the condition of the exudate, and the wound improvement. The percentage of healing rate was 61.45% for the NPWT group and 36.90% for SWC (95% CI: 1.32-1.70). There were significant differences in wound healing time (WMD = -16.47 days, 95% [CI (-22.36, - 10.59) days, P ≤ .001]). The pain score and hospitalization cost in NPWT was lower compared with SWC group (WMD = -2.39, 95% CI [-3.47, -1.30], P ≤ .001); (SMD = -2.55, 95% CI [-4.07, -1.03], P < .01). The frequency of dressing change in both NPWT groups was greatly reduced (SMD = -3.61, 95% [CI (-4.57, - 2.66) times, P ≤ .001]). Our meta-analysis indicated that NPWT was associated with greater improvements in improving PIs and shorting healing time for III/IV PIs. However, this conclusion needs to be confirmed by high-quality multicenter RCTs.

OUTCOMES OF VAC VERSUS CONVENTIONAL DRESSING IN MANAGEMENT OF DIABETIC FOOT ULCER

Background: Foot wounds in people with diabetes mellitus (DM) are common and serious global health issue. Negative pressure wound therapy can be used to treat these wounds and a clear and current overview of current evidence is required to facilitate decision-making regarding its use. Objective: To assess the efficacy of vacuum assisted closure dressings as compared to conventional moist wound dressings in improving the healing process in diabetic foot wounds. Patients and methods: This prospective randomized comparative study was conducted in the General and Vascular Surgery Departments at Al-Azhar university hospitals and Al-Ahrar teaching hospital, in the period from January 2019 to May 2020. The study included 30 patients randomized into two equal groups: VAC therapy and conventional dressing suffering from diabetic foot wounds. All chronic wounds where conventional dressings indicated were included in the study. Results: Wound bed showed signs of healing by granulation tissue formation in 11 among 15 patients (73.3%) in VAC therapy group. In conventional treatment, 4 showed granulation among 15 patients (26.7%) one week after initiation of treatment. (P=0.01). There was a statistically significant difference between average granulation as % of ulcer area and it was significantly high in vacuum dressing. It was 50.2 ± 18.9 in Conventional treatment compared with 77.4 ± 19.3 in NPWT group (p- value = 0.005). Also, at the end of the study, we found that the total mean cost in conventional dressing group was 1993 ± 193 EP compared to 2261 ± 183 EP in VAC group. There was a difference in the total cost finally. Being higher in cost, VAC therapy although has a shorter hospital stay and faster healing time in comparison with conventional dressing. Conclusion: Negative pressure wound therapy (NPWT) using vacuum-assisted closure (VAC) was more efficacious than conventional therapy in the management of foot ulcers in diabetic patients. Hospital stay was significantly shorter in NPWT patients, so less consuming of hospital service than conventional dressing. This is finally decreasing the total budget to the hospital.

Randomized clinical trial of negative pressure wound therapy as an adjunctive treatment for small-area thermal burns in children

BackgroundThe efficacy of negative pressure wound therapy (NPWT) in the acute management of burns remains unclear. The purpose of this trial was to compare standard Acticoat™ and Mepitel™ dressings with combined Acticoat™, Mepitel™ and continuous NPWT to determine the effect of adjunctive NPWT on re‐epithelialization in paediatric burns.MethodsThis two‐arm, single‐centre RCT recruited children with acute thermal burns covering less than 5 per cent of their total body surface area. The primary outcome was time to re‐epithelialization. Blinded assessments were performed using photographs captured every 3–5 days until discharge. Secondary measures included pain, itch, grafting, perfusion and scar management referrals.ResultsSome 114 patients were randomized. Median time to re‐epithelialization was 8 (i.q.r. 7–11) days in the NPWT group and 10 (8–14) days in the control group. In a multivariable model, NPWT decreased the expected time to wound closure by 22 (95 per cent c.i. 7 to 34) per cent (P = 0·005). The risk of referral to scar management was reduced by 60 (18 to 81) per cent (P = 0·013). Four participants in the control group and one in the NPWT group underwent grafting. There were no statistically significant differences between groups in pain, itch or laser Doppler measures of perfusion. Adverse events were rare and minor, although NPWT carried a moderate treatment burden, with ten patients discontinuing early.ConclusionAdjunctive NPWT hastened re‐epithelialization in small‐area burn injuries in children, but had a greater treatment burden than standard dressings alone. Registration number: ACTRN12618000256279 ( http://ANZCTR.org.au).

Negative pressure wound therapy for patients with mediastinitis: A meta-analysis.

To evaluate clinical effects between conditional treatment and negative pressure wound therapy for mediastinal infection. Multiple databases were searched to identify relevant studies, and the articles that eventually satisfied the criteria were included. All the meta‐analyses were conducted with the Review Manager 5.2. To estimate the quality of each article, risk of bias table was performed. Finally, nine studies including 648 patients met the eligibility criteria. The negative pressure wound therapy (NPWT) group and the control group included 353 and 295 patients, respectively. The meta‐analysis showed no significant difference in operative time (RR = −6.13, 95%CI [−50.00, 37.74], P = .78; P for heterogeneity <.000001, I 2 = 100%). The length of hospital stay (MD = −3.07, 95%CI [−4.38, −1.77], P < .00001; P for heterogeneity = .99, I 2 = 0%), re‐infection (RR = 0.18, 100%CI [0.08, 0.40], P < .00001; P for heterogeneity = 0.48, I 2 = 0%), and mortality were significantly different between the two groups (RR = 0.27, 95%CI [0.12, 0.63], P of overall effect = .002). NPWT is a better therapy than conventional treatment for mediastinitis.

Negative-pressure wound therapy compared with standard dressings following surgical treatment of major trauma to the lower limb: the WHiST RCT.

Major trauma is the leading cause of death in people aged < 45 years. Patients with major trauma usually have lower-limb fractures. Surgery to fix the fractures is complicated and the risk of infection may be as high as 27%. The type of dressing applied after surgery could potentially reduce the risk of infection. To assess the deep surgical site infection rate, disability, quality of life, patient assessment of the surgical scar and resource use in patients with surgical incisions associated with fractures following major trauma to the lower limbs treated with incisional negative-pressure wound therapy versus standard dressings. A pragmatic, multicentre, randomised controlled trial. Twenty-four specialist trauma hospitals representing the UK Major Trauma Network. A total of 1548 adult patients were randomised from September 2016 to April 2018. Exclusion criteria included presentation > 72 hours after injury and inability to complete questionnaires. Incisional negative-pressure wound therapy (n = 785), in which a non-adherent absorbent dressing covered with a semipermeable membrane is connected to a pump to create a partial vacuum over the wound, versus standard dressings not involving negative pressure (n = 763). Trial participants and the treating surgeon could not be blinded to treatment allocation. Deep surgical site infection at 30 days was the primary outcome measure. Secondary outcomes were deep infection at 90 days, the results of the Disability Rating Index, health-related quality of life, the results of the Patient and Observer Scar Assessment Scale and resource use collected at 3 and 6 months post surgery. A total of 98% of participants provided primary outcome data. There was no evidence of a difference in the rate of deep surgical site infection at 30 days. The infection rate was 6.7% (50/749) in the standard dressing group and 5.8% (45/770) in the incisional negative-pressure wound therapy group (intention-to-treat odds ratio 0.87; 95% confidence interval 0.57 to 1.33; p = 0.52). There was no difference in the deep surgical site infection rate at 90 days: 13.2% in the standard dressing group and 11.4% in the incisional negative-pressure wound therapy group (odds ratio 0.84, 95% confidence interval 0.59 to 1.19; p = 0.32). There was no difference between the two groups in disability, quality of life or scar appearance at 3 or 6 months. Incisional negative-pressure wound therapy did not reduce the cost of treatment and was associated with a low probability of cost-effectiveness. Owing to the emergency nature of the surgery, we anticipated that some patients who were randomised would subsequently be unable or unwilling to participate. However, the majority of the patients (85%) agreed to participate. Therefore, participants were representative of the population with lower-limb fractures associated with major trauma. The findings of this study do not support the use of negative-pressure wound therapy in patients having surgery for major trauma to the lower limbs. Our work suggests that the use of incisional negative-pressure wound therapy dressings in other at-risk surgical wounds requires further investigation. Future research may also investigate different approaches to reduce postoperative infections, for example the use of topical antibiotic preparations in surgical wounds and the role of orthopaedic implants with antimicrobial coatings when fixing the associated fracture. Current Controlled Trials ISRCTN12702354 and UK Clinical Research Network Portfolio ID20416. This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 38. See the NIHR Journals Library for further project information.

Closed incision negative pressure wound therapy may decrease wound complications in major lower extremity amputations

ObjectiveWound complications after major lower extremity amputations (LEAs) are a cause of significant morbidity in vascular surgery patients. Recent publications have demonstrated the efficacy of the closed incision negative pressure dressing at preventing surgical site infections (SSIs); however, there are few data on its use in major LEAs. This study sought to assess if closed incision negative pressure wound therapy (NPWT) would decrease the risk of complications as compared with a standard dressing in patients with peripheral vascular disease undergoing major LEA. MethodsFifty-four consecutive patient limbs with a history of peripheral arterial disease underwent below-knee or above-knee amputations. This was a retrospective review of a prospectively maintained database from January 2018 to December 2019, and it included 23 amputations in the NPWT group and 31 amputations in the standard dressing group. NPWT using the PREVENA system was applied intraoperatively at the discretion of the operating surgeon and removed 5 to 7 days postoperatively. The standard group received a nonadherent dressing with an overlying compression dressing. Amputation incisions were assessed and wound complications were recorded. Student's t-test and two-sample proportion z-test were used for statistical analysis. A P value of less than .05 was considered statistically significant. ResultsFor comorbidities, there was a higher incidence of tobacco use in the NPWT as compared with the standard group (44% vs 13%; P = .011), as well as trends toward increased prior amputations, anemia, hyperlipidemia, and chronic obstructive pulmonary disorder in the NPWT group. For risk factors, there were more dirty wounds in the NPWT as compared with the standard group (52% vs 26%; P = .046). For outcomes, there were fewer wound complications in the NPWT as compared with the standard group (13% vs 39%; P = .037). The types of wound-related complications in the NPWT group included one wound dehiscence with a deep SSI, one superficial SSI, and one incision line necrosis. In the standard group, there were four wound dehiscences with deep SSI, three superficial SSIs, four incision line necroses, and one stump hematoma. The rates of perioperative mortality and amputation revision did not differ significantly between the NPWT and the standard groups (3% vs 4% and 4.3% vs 10%, respectively). ConclusionsClosed incision NPWT may decrease the incidence of wound complications in vascular patients undergoing major LEA. This held true even among a population that was potentially at higher risk. This therapy may be considered for use in lower extremity major amputations.

Clinical application of negative-pressure wound therapy in split-thickness skin grafting at hard-to-fix sites

Objective: To compare the clinical effects of continuous negative-pressure wound therapy (NPWT) and conventional pressure dressing at at hard-to-fix sites after split-thickness skin grafting. Methods: From September 2017 to August 2019, 129 patients who met the inclusion criteria and had spilt-thickness skin grafting at hard-to-fix sites were admitted to the First Affiliated Hospital of Air Force Medical University and included in this retrospective cohort study. The patients were divided into NPWT group (67 patients, 41 males and 26 females, aged (32±6) years) and conventional pressure dressing group (62 patients, 37 males and 25 females, aged (30±5) years) according to whether the hard-to-fix sites were applied with NPWT after spilt-thickness skin grafting. After debridement and spilt-thickness skin grafting at hard-to-fix sites in patients of 2 groups, the wounds of patients in conventional pressure dressing group were applied with conventional pressure bandaging after being filled with dry gauze; for the wounds of patients in NPWT group, the semi-permeable membrane was pasted and sealed for continuous negative pressure suction after filled with dry gauze and placed the drainage foam or drainage tube, with the negative pressure ranging from -16.6 to -9.9 kPa. The bandage was opened during the first dressing change on the 5th day after surgery in NPWT group and on the 7th day after surgery in conventional pressure dressing group. The skin graft surviving area and proportion, the area and proportion of hematoma, the incidence of common complications of skin graft were observed and calculated. The times of postoperative dressing change and the length of hospital stay were counted. Data were statistically analyzed with two independent sample t test, Cochran & Cox approximate t test, chi-square test, and Fisher's exact probability test. Results: (1) At the first dressing change, the skin graft surviving area of patients in NPWT group was (420±94) cm(2), which was significantly larger than (322±97) cm(2) in conventional pressure dressing group (t'=12.33, P<0.01); the skin graft surviving area proportion of patients in NPWT group was (97.0±2.3)%, which was significantly higher than (74.4±4.8)% in conventional pressure dressing group (t'=50.11, P<0.01). (2) At the first dressing change, the skin hematoma area of patients in conventional pressure dressing group was (31.7±10.1) cm(2), which was significantly larger than (3.2±0.7) cm(2) in NPWT group (t'=23.04, P<0.01); the skin hematoma area proportion of patients in conventional pressure dressing group was (7.3±2.3)%, which was significantly higher than (0.7±0.3)% in NPWT group (t'=76.21, P<0.01). (3) At the first dressing change, there was 1 case of skin movement and no case of skin graft edge tear in NPWT group with an incidence of 1.5% (1/67). In the conventional pressure dressing group, there were 4 cases of skin movement and 2 cases of skin graft edge tear with an incidence of 9.7% (6/62), P<0.05. The incidence of complication of skin graft of patients in NPWT group was significantly lower than that in conventional pressure dressing group (P<0.05). (4) The times of postoperative dressing change of patients in NPWT group was significantly less than that in conventional pressure dressing group (t=7.93, P<0.01). The postoperative length of hospital stay in NPWT group was significantly less than that in conventional pressure dressing group (t=11.71, P<0.01). Conclusions: Continuous NPWT can effectively promote wound healing, improve the survival rate of skin graft, reduce the incidence of complications after skin grafting, and shorten the length of hospital stay in split-thickness skin grafting at hard-to-fix sites.

Treatment of hard-to-heal leg ulcers with hyaluronic acid, sodium alginate and negative pressure wound therapy

Hard-to-heal lower extremity ulcer is a common healthcare problem and can lead to a poor quality of life (QoL). Despite the advances in wound care, conventional therapies, such as necrotic tissue debridement, cleansing, treatment of infection and local treatment with dressing application are still considered the standard of care in patients with hard-to-heal leg ulcers. However, managing hard-to-heal ulcers that do not respond well to these methods has led to new treatment strategies. In this study, the effects of hyaluronic acid (HA) and sodium alginate (SA), combined with negative pressure wound therapy (NPWT), in patients with hard-to-heal leg ulcers are evaluated. Patients with hard-to-heal lower extremity ulcers were treated with HA-SA combined with NPWT (HA-SA-NWPT, n=11), or conventional therapy (n=14), between June 2014 and September 2015. Demographics, comorbidities, time to complete healing and change in wound area were recorded and compared. A total of 25 patients took part. Complete healing was achieved in 63.6% (n=7) of the patients in the HA-SA with NPWT group, compared with 14.3% (n=2) of the patients in the conventional therapy group (p=0.017). The mean decrease in wound size was significantly higher in the HA-SA-NPWT group than in the conventional therapy group (73.8% versus 34.8%, respectively, p=0.029). Despite a shorter healing period in the HA-SA-NPWT group than in the conventional group, no statistically significant difference was found between groups for time to complete healing (37 days versus 55 days, respectively). These results demonstrate that the combination of HA-SA-NPWT is a promising treatment for decreasing the healing time and increasing the success rate by their synergistic effect on wound healing in hard-to-heal lower extremity ulcers. However, further studies with a larger number of patients are needed to confirm the results.

Negative Pressure Wound Therapy Compared to Petrolatum Gauze and a Bogota Bag to Manage Postoperative Midline Abdominal Wound Dehiscence: A Pilot, Nonrandomized Controlled Trial

A study was conducted to evaluate the efficacy of NPWT for fascial closure/cutaneous cover compared to non-NPWT treatment using petrolatum gauze and a Bogota bag in patients with postoperative laparotomy wound dehiscence. A single center, prospective, nonrandomized pilot study was conducted. Using convenience sampling methods, consecutive patients on 6 different surgical units who were at least 18 years of age and who developed postoperative abdominal wound dehiscence following elective and emergency laparotomy from January 2017 to December 2018 were recruited. NPWT dressing with polyvinyl white foam sponge or loosely packed, saline-soaked petrolatum gauze followed by Bogota bag application were used and compared. Baseline patient demographics and history were collected, and patients were followed for an average of 6 months after surgery. Number of days until first signs of granulation tissue appearance, time until complete granulation tissue cover/fascial surgical closure, and hospital discharge were compared. Categorical variables (gender, comorbidities, presence or absence of stoma, exposure to prior radiotherapy) were expressed as proportions and analyzed using chi-squared test or Fischer's exact test. Continuous variables such as age, body mass index, albumin, postoperative hospital stay, and number of days required for decision for fascial closure were expressed as Mean ± standard deviation and analyzed using an independent t test or Mann Whitney U test based on whether the data followed normal distribution. Postoperative day of wound dehiscence, the number of days for the appearance of granulation tissue, and the number of NPWT placements required also were assessed using Mean ± standard deviation and analyzed using an independent t test. A P value <.05 was considered significant. Sixty (60) patients were included, but 4 in NPWT group and 10 in the non-NPWT group could not complete the study, leaving 26 patients in NPWT group and 20 patients in non-NPWT group. Demographic and surgical variables were not significantly different. Patients in both groups achieved complete wound coverage by surgical closure or healing by secondary intention. Days until first signs of granulation tissue (2.92 vs. 6.65; P <.001), number of days until fascial closure (15.50 vs. 29.50; P <.001), and length of postoperative hospital stay (24.30 vs. 37.90; P <.001) were significantly less in NPWT group. Two (2) patients (7.6%) in the NPWT developed a fistula during the 6-month follow-up period. No fistulas developed in the control group, and no intra-abdominal abscesses, ventral hernias, or wound dehiscence were reported in either group. Time until first signs of granulation tissue appearance and complete granulation tissue coverage was significantly shorter in the NPWT group, but time until definitive closure was not evaluated. Randomized, controlled clinical studies to compare definitive time to wound closure and long-term follow up to evaluate long-term complication rates, including the risk of developing fistulas, are warranted.

Adaptive expression of biofilm regulators and adhesion factors of Staphylococcus aureus during acute wound infection under the treatment of negative pressure wound therapy in vivo.

Negative pressure wound therapy (NPWT) is gaining acceptance as a physical therapy for a wide variety of infected wounds. To gain insight into the response of bacteria to NPWT in vivo, the adaptive expression of biofilm regulators and adhesion factors of Staphylococcus aureus (S. aureus), the most frequently isolated pathogen in the clinic, during acute wound infection was investigated. A 3 cm full-thickness dermal wound was created on each side of a rabbit back and inoculated with green fluorescent protein-labeled S. aureus. NPWT was initiated at 6 h post inoculation, with the wound on the contralateral side as the untreated self-control. The wounds were subjected to a 28 day observation period. Histological analysis, laser scanning confocal microscopy and scanning electron microscopy revealed a transition of S. aureus to a free-living phenotype in tissues treated with NPWT, compared with microcolonies in untreated wounds. Viable bacteria counts showed a modest reduction in the bioburden of NPWT group on day 8 (P<0.001), with ~1x106 colony-forming units/g tissue. Transcript analysis of biofilm- and colonization-related genes were investigated using reverse transcription-quantitative PCR on postoperative days 1, 2, 4 and 8. The poly-beta-1,6-N-acetyl-D-glucosamine synthase locus and holin-like protein CidA/antiholin-like protein LrgA network were less active in the NPWT group compared with the untreated control group. Accordingly, the expression profile switched to an elevated expression of the adhesive factors UDP-phosphate N-acetylglucosaminyl 1-phosphate transferase (at days 0-4) and fibronectin-binding protein A and iron-regulated surface determinant protein A at >4 days during both stages of colonization. Meanwhile, low expression levels of the effector molecule (RNAIII) of the accessory gene regulator type I (agr) system was detected in NPWT group, suggesting that the bacterial density in NPWT-treated wounds was under the threshold for agr activation, thus not leading to an active and invasive infection. The wounds treated by NPWT healed completely on day 28, compared with an average of an 8.11% defect area in the control group (P<0.001). The results of the current study indicated that S. aureus responds to NPWT by regulating gene expression, manifesting a decrease in biofilm formation and an increase in bacterial colonization in vivo, which potentially benefits the wound repair and healing process.

Result of negative pressure wound therapy in open fracture

Introduction: Open fractures are associated with a high incidence of mainly osteomyelitis. Negative pressure wound therapy (NPWT) is a novel form of treatment that uses sub atmospheric pressure to effect early wound healing. Objectives and study design: To determine the effect of NPWT on incidence of deep infections/ osteomyelitis after open fractures using a prospective randomized study design. Materials and methods: Ninety-five open fractures were randomized into two groups receiving NPWT and the second group undergoing periodic irrigation, cleaning and debridement respectively. The wounds were closed or covered on shrinkage in size and sufficient granulation. Evidence of infection was sought during the course of treatment and follow up. Also, serial cultures were sent every time the wound was cleaned. Results and conclusions: Patients in the control group developed a total of 19 infections (42.21%) as opposed to only 5 (10%) in the NPWT group. FOURTY SEVEN patients developed positive growth when samples were sent for culture with 5 (4.75%) in the NPWT group and 42 (39.9%) in the control group. Only 21 patients (22.2%) went on the develop osteomyelitis, among them 5(10%) patients are in npwt grup and 16(35.55%) are in control group. Thus, negative pressure wound therapy is indeed beneficial for preventing the incidence of both acute infections and osteomyelitis in open fractures. However, a significant difference was seen in the time required for the wound to be ready for delayed primary closure or coverage.