Major complications during negative pressure wound therapy in poststernotomy mediastinitis after cardiac surgery

Negative pressure wound therapy in patients with diabetes undergoing left internal thoracic artery harvest: A randomized control trial

BACKGROUND

Patients with diabetes undergoing CABG are at risk of wound infection. Incisional negative pressure wound therapy has been shown to be effective in decreasing incidence of infection in high-risk wounds. Near infrared spectroscopy (NIRS) can be used to assess wound oxygenation and low values can predict infection.

OBJECTIVES

To evaluate utility of NIRS to assess wound oxygenation, to assess effect of sternotomy, left internal thoracic artery harvest, and wound dressing type on wound edge oxygenation.

METHODS

In this blinded randomized control trial, patients with diabetes undergoing isolated coronary artery bypass grafting with a left internal thoracic artery were randomized to receive either incisional negative pressure wound therapy dressing or a standard dressing. NIRS measurements were made on the left upper arm (control), and left and right parasternal regions on day -1 (preoperative), day 5, and week 6 after surgery. Results were analyzed using repeated measures parametric methods.

RESULTS

Eighty patients with diabetes were recruited, 40 to the incisional negative pressure wound therapy group and 40 to the standard dressing group. Adjusted NIRS readings dropped significantly in all patients by day 5 and partially recovered by week 6. In both groups, there was no difference between readings on the left and right. At all time points and on both sides, there was no difference in readings between patients in the 2 groups.

CONCLUSIONS

NIRS can be used to assess oxygenation adjacent to a sternotomy wound. Adjusted tissue oxygen levels change with time after sternotomy and left internal thoracic artery harvest in patients with diabetes. Wound dressing type does not influence day 5 wound edge oxygenation.

The role of negative pressure wound therapy with instillation and dwell time in the treatment of deep sternal wound infections-A retrospective cohort study

Background and Aims

Negative pressure wound therapy (NPWT) has gained a central role in the treatment of deep sternal wound infections (DSWIs) after median thoracotomy. Our study aims at proving the safety of using NPWT with instillation and dwell time (NPWTi-d) in the treatment of DSWI.

Methods

We retrospectively evaluated the patients who were treated at our institution between March 2018 and November 2021 for DSWI after radical sternectomy using NPWT or NPWTi-d. The NPWTi-d was applied to start the first postoperative day using 75 mmHg negative pressure for 3 h, followed by instillation of sodium hypochlorite <0.08% with a 3-min dwell time.

Results

The NPWTi-d group showed a shorter length of stay (29.39 ± 12.09 vs. 39.54 ± 17.07 days; p = 0.049), a shorter elapsed time between the debridement and the flap coverage (7.18 ± 4.27 vs. 11.86 ± 7.7 days; p = 0.003) and less operative or nonoperative dressing changes (1.73 ± 1.14 vs. 2.68 ± 56; p < 0.001). The in-hospital mortality was 8.2%, with no significant differences between the two groups (p = 1).

Conclusion

NPWTi-d can be safely employed in the treatment of DSWI. Further prospective randomized studies need to establish the role of NPWTi-d in the control of infection and biofilm as well as in wound healing.

Combined negative pressure wound therapy with irrigation and dwell time and artificial dermis prevents infection and promotes granulation formation in a ruptured giant omphalocele: a case report

Background

Omphalocele is a congenital abdominal wall defect of the umbilical cord insertion site. A giant omphalocele, with a fascial defect > 5 cm in diameter and/or containing > 50% of the liver within the hernia sac, can be challenging for pediatric surgeons. Recently, negative pressure wound therapy has been reported as an effective management for giant omphaloceles; however, it is not recommended for an infected wound with necrotic tissue as it may exacerbate infection. We adopted negative pressure wound therapy with irrigation and dwell time (NPWTi-d) for a case of a ruptured giant omphalocele. Artificial membranes, followed by artificial dermis, were used to promote fibrous capsule formation, and then NPWTi-d was used to promote granulation while controlling infection. However, studies have not been conducted regarding NPWTi-d for ruptured giant omphaloceles; hence, we present our treatment experience with NPWTi-d for a giant omphalocele.

Case presentation

The patient was a boy born at 38 weeks and 3 days of gestation, weighing 1896 g. He was diagnosed with a ruptured giant omphalocele with a total liver and intestine defect hole of 10 cm × 10 cm. The patient underwent silo placement using an artificial mesh, followed by plicating the artificial mesh at 4 days of age. The herniated viscera were gradually reduced into the abdominal cavity; however, the defect size was still large. Hence, a collagen-based artificial dermis was patched on the defect hole. After creating a fresh and smooth granulated tissue, NPWTi-d was applied at 33 days of age to promote granulation and control infection. We used the 3 M™ V.A.C.® Ulta Therapy Unit with 3 M™ VeraFlo™ therapy. NPWTi-d was stopped at 60 days of age when the granulation tissue was well formed including at the artificial dermis site. The wound was managed with prostandin ointment and appropriate debridement, resulting in complete epithelialization at 5 months of age.

Conclusions

Artificial membranes followed by artificial dermis were used to promote a fibrous capsule and artificial dermis granulation, which protects against organ damage. NPWTi-d achieved better control of infection and promoted wound healing. NPWTi-d combined with artificial dermis can effectively treat ruptured giant omphaloceles.

Negative pressure wound therapy for surgical wounds healing by primary closure

BACKGROUND

Indications for the use of negative pressure wound therapy (NPWT) are broad and include prophylaxis for surgical site infections (SSIs). Existing evidence for the effectiveness of NPWT on postoperative wounds healing by primary closure remains uncertain.

OBJECTIVES

To assess the effects of NPWT for preventing SSI in wounds healing through primary closure, and to assess the cost-effectiveness of NPWT in wounds healing through primary closure.

SEARCH METHODS

In January 2021, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries and references of included studies, systematic reviews and health technology reports. There were no restrictions on language, publication date or study setting.

SELECTION CRITERIA

We included trials if they allocated participants to treatment randomly and compared NPWT with any other type of wound dressing, or compared one type of NPWT with another.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trials using predetermined inclusion criteria. We carried out data extraction, assessment using the Cochrane risk of bias tool, and quality assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology. Our primary outcomes were SSI, mortality, and wound dehiscence.

MAIN RESULTS

In this fourth update, we added 18 new randomised controlled trials (RCTs) and one new economic study, resulting in a total of 62 RCTs (13,340 included participants) and six economic studies. Studies evaluated NPWT in a wide range of surgeries, including orthopaedic, obstetric, vascular and general procedures. All studies compared NPWT with standard dressings. Most studies had unclear or high risk of bias for at least one key domain. Primary outcomes Eleven studies (6384 participants) which reported mortality were pooled. There is low-certainty evidence showing there may be a reduced risk of death after surgery for people treated with NPWT (0.84%) compared with standard dressings (1.17%) but there is uncertainty around this as confidence intervals include risk of benefits and harm; risk ratio (RR) 0.78 (95% CI 0.47 to 1.30; I² = 0%). Fifty-four studies reported SSI; 44 studies (11,403 participants) were pooled. There is moderate-certainty evidence that NPWT probably results in fewer SSIs (8.7% of participants) than treatment with standard dressings (11.75%) after surgery; RR 0.73 (95% CI 0.63 to 0.85; I² = 29%). Thirty studies reported wound dehiscence; 23 studies (8724 participants) were pooled. There is moderate-certainty evidence that there is probably little or no difference in dehiscence between people treated with NPWT (6.62%) and those treated with standard dressing (6.97%), although there is imprecision around the estimate that includes risk of benefit and harms; RR 0.97 (95% CI 0.82 to 1.16; I² = 4%). Evidence was downgraded for imprecision, risk of bias, or a combination of these. Secondary outcomes There is low-certainty evidence for the outcomes of reoperation and seroma; in each case, confidence intervals included both benefit and harm. There may be a reduced risk of reoperation favouring the standard dressing arm, but this was imprecise: RR 1.13 (95% CI 0.91 to 1.41; I² = 2%; 18 trials; 6272 participants). There may be a reduced risk of seroma for people treated with NPWT but this is imprecise: the RR was 0.82 (95% CI 0.65 to 1.05; I² = 0%; 15 trials; 5436 participants). For skin blisters, there is low-certainty evidence that people treated with NPWT may be more likely to develop skin blisters compared with those treated with standard dressing (RR 3.55; 95% CI 1.43 to 8.77; I² = 74%; 11 trials; 5015 participants). The effect of NPWT on haematoma is uncertain (RR 0.79; 95 % CI 0.48 to 1.30; I² = 0%; 17 trials; 5909 participants; very low-certainty evidence). There is low-certainty evidence of little to no difference in reported pain between groups. Pain was measured in different ways and most studies could not be pooled; this GRADE assessment is based on all fourteen trials reporting pain; the pooled RR for the proportion of participants who experienced pain was 1.52 (95% CI 0.20, 11.31; I² = 34%; two studies; 632 participants). Cost-effectiveness Six economic studies, based wholly or partially on trials in our review, assessed the cost-effectiveness of NPWT compared with standard care. They considered NPWT in five indications: caesarean sections in obese women; surgery for lower limb fracture; knee/hip arthroplasty; coronary artery bypass grafts; and vascular surgery with inguinal incisions. They calculated quality-adjusted life-years or an equivalent, and produced estimates of the treatments' relative cost-effectiveness. The reporting quality was good but the evidence certainty varied from moderate to very low. There is moderate-certainty evidence that NPWT in surgery for lower limb fracture was not cost-effective at any threshold of willingness-to-pay and that NPWT is probably cost-effective in obese women undergoing caesarean section. Other studies found low or very low-certainty evidence indicating that NPWT may be cost-effective for the indications assessed.

AUTHORS' CONCLUSIONS

People with primary closure of their surgical wound and treated prophylactically with NPWT following surgery probably experience fewer SSIs  than people treated with standard dressings but there is probably no difference in wound dehiscence (moderate-certainty evidence). There may be a reduced risk of death after surgery for people treated with NPWT compared with standard dressings but there is uncertainty around this as confidence intervals include risk of benefit and harm (low-certainty evidence). People treated with NPWT may experience more instances of skin blistering compared with standard dressing treatment (low-certainty evidence). There are no clear differences in other secondary outcomes where most evidence is low or very low-certainty. Assessments of cost-effectiveness of NPWT produced differing results in different indications. There is a large number of ongoing studies, the results of which may change the findings of this review. Decisions about use of NPWT should take into account surgical indication and setting and consider evidence for all outcomes.

Outcome of Prophylactic Postoperative Negative Pressure Wound Treatment in Colorectal Cancer Patients

BACKGROUND

Wound infection is a common cause of morbidity in colorectal surgery. We speculated that a prophylactic Negative Pressure Wound Treatment (NPWT) is associated with less postoperative wound complications for colorectal cancer patients who undergo a colectomy.

METHODS

Multivariate analysis was used to investigate the association between NPWT and wound complications for patients with colorectal cancer who underwent a colectomy using data from the National Surgical Quality Improvement Program (NSQIP) database during the 2013 - 2019 period.

RESULTS

We investigated 96 105 patients who underwent colectomy for colorectal cancer during 2013-2019 within the database. Negative Pressure Wound Treatment was utilized for 270 patients following the principal procedure (.3%). Patients who had NPWT had dirtier wounds, less bowel preparation, more extensive surgery (total colectomy vs partial colectomy), higher stoma creation, and more non-elective operations. Multiple factors were associated with postoperative wound complications such as smoking Adjusted Odd Ratio (AOR:1.27, P < .01), chronic steroid use (AOR: 1.30, P < .01), obesity (AOR: 1.54, P < .01), and serum albumin level less than 3.5 g/dL (AOR: 1.29, P < .01). Overall, there was no significant decrease in wound complications using NPWT (AOR: .66, P = .14). However, a sub-group of patients who underwent emergent/urgent operation had a significant lower risk of wound complications using NPWT (AOR: .3, CI: .09-.99, P = .04).

CONCLUSION

Prophylactic NPWT is associated with a decrease in wound complications of patients who underwent an emergent/urgent colectomy for colorectal cancer. However, we could not find any significant decrease in wound complications for elective colorectal procedures for colorectal cancer. Further clinical trials are needed to confirm these study results.

Post-CABG Deep Sternal Wound Infection: A Retrospective Comparative Analysis of Early versus Late Referral to a Plastic Surgery Unit in a Tertiary Care Center

Background  Deep sternal wound infections (DSWI) following median sternotomy are initially treated by the cardiothoracic surgeons and are referred to a plastic surgical unit late in the course of time.

Methods  This is a retrospective review done in a tertiary care teaching institute from January 2005 to June 2018 and the data of 72 patients who had DSWI out of 4,214 patients who underwent median sternotomy for coronary artery bypass grafting (CABG) was collected with respect to the duration between CABG and presentation of DSWI as well as time of referral to a plastic surgery unit. We defined early referral as < or equal to 15 days from presentation and late referral as > 15 days. Both groups were compared with respect to multiple parameters as well as early and late postoperative course, postoperative complications, and mortality.

Results  The early group had 33 patients, while the late group had 39 patients. The number of procedures done by the cardiothoracic team before referral to the plastic surgery unit is significant ( p = 0.002). The average duration from the presentation of DSWI to definitive surgery was found to be 16.58 days in the early group and 89.36 days in the late group. The rest of the variables that were compared in both the groups did not have significant differences.

Conclusion  There is no statistical difference between early and late referral to plastic surgery in terms of mortality and morbidity. Yet, early referrals could lead to highly significant reduction in total duration of hospital stay, wound healing, and costs. Early referral of post-CABG DSWIs to Plastic surgeons by the cardiothoracic surgeons is highly recommended.

The management of deep sternal wound infection: Literature review and reconstructive algorithm

Deep sternal wound infection (DSWI) is an important complication of open thoracic surgery, with a reported incidence of 0.5-6%. Given its association with increased morbidity, mortality, inpatient duration, financial burden, and re-operation rates, an aggressive approach to treatment is mandated. Flap reconstruction has become the standard of care, with studies demonstrating improved outcomes with reduced mortality and resource usage in patients undergoing early versus delayed flap reconstruction. Despite this, no evidence-based standard for the management of DSWI exists. We performed a thorough review of the literature to identify principles in management, using a PRISMA compliant methodology. Ovid-Embase, Medline and PubMed databases were searched for relevant papers using the search terms "deep sternal wound infection," and "post-sternotomy mediastinitis" to December 2019. Duplicates were removed, and the search narrowed to look at specific areas of interest i.e. negative pressure wound therapy, flap reconstruction, and rigid fixation. The reference list of included articles underwent full text review. No randomized controlled trials were identified. We review the current management techniques for patients with DSWI, and raise awareness for the need for further high quality studies, and a standardized national cardiothoracic-plastic surgery guideline to guide management. Based on our findings and the authors' own experience in this area, we provide evidence-based recommendations. We also propose a reconstructive algorithm.

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, I2 = 100%). The length of hospital stay (MD = -3.07, 95%CI [-4.38, -1.77], P < .00001; P for heterogeneity = .99, I2 = 0%), re-infection (RR = 0.18, 100%CI [0.08, 0.40], P < .00001; P for heterogeneity = 0.48, I2 = 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 for surgical wounds healing by primary closure

BACKGROUND

Indications for the use of negative pressure wound therapy (NPWT) are broad and include prophylaxis for surgical site infections (SSIs). Existing evidence for the effectiveness of NPWT on postoperative wounds healing by primary closure remains uncertain.

OBJECTIVES

To assess the effects of NPWT for preventing SSI in wounds healing through primary closure, and to assess the cost-effectiveness of NPWT in wounds healing through primary closure.

SEARCH METHODS

In June 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries and references of included studies, systematic reviews and health technology reports. There were no restrictions on language, publication date or study setting.

SELECTION CRITERIA

We included trials if they allocated participants to treatment randomly and compared NPWT with any other type of wound dressing, or compared one type of NPWT with another type of NPWT.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trials using predetermined inclusion criteria. We carried out data extraction, assessment using the Cochrane 'Risk of bias' tool, and quality assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology.

MAIN RESULTS

In this third update, we added 15 new randomised controlled trials (RCTs) and three new economic studies, resulting in a total of 44 RCTs (7447 included participants) and five economic studies. Studies evaluated NPWT in the context of a wide range of surgeries including orthopaedic, obstetric, vascular and general procedures. Economic studies assessed NPWT in orthopaedic, obstetric and general surgical settings. All studies compared NPWT with standard dressings. Most studies had unclear or high risk of bias for at least one key domain. Primary outcomes Four studies (2107 participants) reported mortality. There is low-certainty evidence (downgraded twice for imprecision) showing no clear difference in the risk of death after surgery for people treated with NPWT (2.3%) compared with standard dressings (2.7%) (risk ratio (RR) 0.86; 95% confidence interval (CI) 0.50 to 1.47; I² = 0%). Thirty-nine studies reported SSI; 31 of these (6204 participants), were included in meta-analysis. There is moderate-certainty evidence (downgraded once for risk of bias) that NPWT probably results in fewer SSI (8.8% of participants) than treatment with standard dressings (13.0% of participants) after surgery; RR 0.66 (95% CI 0.55 to 0.80 ; I² = 23%). Eighteen studies reported dehiscence; 14 of these (3809 participants) were included in meta-analysis. There is low-certainty evidence (downgraded once for risk of bias and once for imprecision) showing no clear difference in the risk of dehiscence after surgery for NPWT (5.3% of participants) compared with standard dressings (6.2% of participants) (RR 0.88, 95% CI 0.69 to 1.13; I² = 0%). Secondary outcomes There is low-certainty evidence showing no clear difference between NPWT and standard treatment for the outcomes of reoperation and incidence of seroma. For reoperation, the RR was 1.04 (95% CI 0.78 to 1.41; I² = 13%; 12 trials; 3523 participants); for seroma, the RR was 0.72 (95% CI 0.50 to 1.05; I² = 0%; seven trials; 729 participants). The effect of NPWT on occurrence of haematoma or skin blisters is uncertain (very low-certainty evidence); for haematoma, the RR was 0.67 (95% CI 0.28 to 1.59; I² = 0%; nine trials; 1202 participants) and for blisters the RR was 2.64 (95% CI 0.65 to 10.68; I² = 69%; seven trials; 796 participants). The overall effect of NPWT on pain is uncertain (very low-certainty evidence from seven trials (2218 participants) which reported disparate measures of pain); but moderate-certainty evidence suggests there is probably little difference between the groups in pain after three or six months following surgery for lower limb fracture (one trial, 1549 participants). There is also moderate-certainty evidence for women undergoing caesarean sections (one trial, 876 participants) and people having surgery for lower limb fractures (one trial, 1549 participants) that there is probably little difference in quality of life scores at 30 days or 3 or 6 months, respectively. Cost-effectiveness Five economic studies, based wholly or partially on trials included in our review, assessed the cost-effectiveness of NPWT compared with standard care. They considered NPWT in four indications: caesarean sections in obese women; surgery for lower limb fracture; knee/hip arthroplasty and coronary artery bypass graft surgery. They calculated quality-adjusted life-years for treatment groups and produced estimates of the treatments' relative cost-effectiveness. The reporting quality was good but the grade of the evidence varied from moderate to very low. There is moderate-certainty evidence that NPWT in surgery for lower limb fracture was not cost-effective at any threshold of willingness-to-pay and that NPWT is probably cost-effective in obese women undergoing caesarean section. Other studies found low or very low-certainty evidence indicating that NPWT may be cost-effective for the indications assessed.

AUTHORS' CONCLUSIONS

People experiencing primary wound closure of their surgical wound and treated prophylactically with NPWT following surgery probably experience fewer SSI than people treated with standard dressings (moderate-certainty evidence). There is no clear difference in number of deaths or wound dehiscence between people treated with NPWT and standard dressings (low-certainty evidence). There are also no clear differences in secondary outcomes where all evidence was low or very low-certainty. In caesarean section in obese women and surgery for lower limb fracture, there is probably little difference in quality of life scores (moderate-certainty evidence). Most evidence on pain is very low-certainty, but there is probably no difference in pain between NPWT and standard dressings after surgery for lower limb fracture (moderate-certainty evidence). Assessments of cost-effectiveness of NPWT produced differing results in different indications. There is a large number of ongoing studies, the results of which may change the findings of this review. Decisions about use of NPWT should take into account surgical indication and setting and consider evidence for all outcomes.

Inpatient Versus Outpatient Management of Negative Pressure Wound Therapy in Pediatric Patients

BACKGROUND

Negative pressure wound therapy (NPWT) is commonly used to manage complex wounds in the pediatric population. With recently developed portable NPWT devices, providers have the opportunity to transition NPWT to the outpatient setting. However, there are no studies describing outpatient NPWT in pediatric patients. Therefore, the purpose of our study was to leverage a population-level analysis to advance our current knowledge about outpatient NPWT use in pediatric patients.

MATERIALS AND METHODS

We analyzed the Truven Health Analytics MarketScan Commercial Claims Database from 2006 to 2014 to identify children treated with NPWT. We compared patient characteristics, indications, complications before and after NPWT, health care utilization within 30 d of NPWT initiation, and health care cost profile of patients treated with NPWT primarily as outpatients versus inpatients. Outpatient NPWT was defined as patients with ≤50% of NPWT coded during an inpatient hospitalization, whereas inpatient NPWT was defined as patients with >50% of NPWT.

RESULTS

We identified 3184 patients (1621 inpatients and 1563 outpatients) aged 0-17 y, who were treated with NPWT from 2006 to 2014. Outpatient NPWT was implemented across multiple ages, comorbidities, and indications, with a low complication rate (2.4%). After controlling for hematologic comorbidity and indications, outpatient NPWT was associated with lower risk of complications (odds ratio: 0.57, 95% confidence interval 0.38-0.86) and lower median total costs ($5602.03) compared with inpatient ($15,233.21) therapy.

CONCLUSIONS

Outpatient NPWT management in pediatric patients was associated with low complication rates. Additional studies are necessary to determine the most overall cost-effective treatment setting for NPWT in the pediatric population.

Negative pressure wound therapy for surgical wounds healing by primary closure

BACKGROUND

Indications for the use of negative pressure wound therapy (NPWT) are broad and include prophylaxis for surgical site infections (SSIs). Existing evidence for the effectiveness of NPWT on postoperative wounds healing by primary closure remains uncertain.

OBJECTIVES

To assess the effects of NPWT for preventing SSI in wounds healing through primary closure, and to assess the cost-effectiveness of NPWT in wounds healing through primary closure.

SEARCH METHODS

In June 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries and references of included studies, systematic reviews and health technology reports. There were no restrictions on language, publication date or study setting.

SELECTION CRITERIA

We included trials if they allocated participants to treatment randomly and compared NPWT with any other type of wound dressing, or compared one type of NPWT with another type of NPWT.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trials using predetermined inclusion criteria. We carried out data extraction, assessment using the Cochrane 'Risk of bias' tool, and quality assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology.

MAIN RESULTS

In this third update, we added 15 new randomised controlled trials (RCTs) and three new economic studies, resulting in a total of 44 RCTs (7447 included participants) and five economic studies. Studies evaluated NPWT in the context of a wide range of surgeries including orthopaedic, obstetric, vascular and general procedures. Economic studies assessed NPWT in orthopaedic, obstetric and general surgical settings. All studies compared NPWT with standard dressings. Most studies had unclear or high risk of bias for at least one key domain. Primary outcomes Four studies (2107 participants) reported mortality. There is low-certainty evidence (downgraded twice for imprecision) showing no clear difference in the risk of death after surgery for people treated with NPWT (2.3%) compared with standard dressings (2.7%) (risk ratio (RR) 0.86; 95% confidence interval (CI) 0.50 to 1.47; I² = 0%). Thirty-nine studies reported SSI; 31 of these (6204 participants), were included in meta-analysis. There is moderate-certainty evidence (downgraded once for risk of bias) that NPWT probably results in fewer SSI (8.8% of participants) than treatment with standard dressings (13.0% of participants) after surgery; RR 0.66 (95% CI 0.55 to 0.80 ; I² = 23%). Eighteen studies reported dehiscence; 14 of these (3809 participants) were included in meta-analysis. There is low-certainty evidence (downgraded once for risk of bias and once for imprecision) showing no clear difference in the risk of dehiscence after surgery for NPWT (5.3% of participants) compared with standard dressings (6.2% of participants) (RR 0.88, 95% CI 0.69 to 1.13; I² = 0%). Secondary outcomes There is low-certainty evidence showing no clear difference between NPWT and standard treatment for the outcomes of reoperation and incidence of seroma. For reoperation, the RR was 1.04 (95% CI 0.78 to 1.41; I² = 13%; 12 trials; 3523 participants); for seroma, the RR was 0.72 (95% CI 0.50 to 1.05; I² = 0%; seven trials; 729 participants). The effect of NPWT on occurrence of haematoma or skin blisters is uncertain (very low-certainty evidence); for haematoma, the RR was 0.67 (95% CI 0.28 to 1.59; I² = 0%; nine trials; 1202 participants) and for blisters the RR was 2.64 (95% CI 0.65 to 10.68; I² = 69%; seven trials; 796 participants). The overall effect of NPWT on pain is uncertain (very low-certainty evidence from seven trials (2218 participants) which reported disparate measures of pain); but moderate-certainty evidence suggests there is probably little difference between the groups in pain after three or six months following surgery for lower limb fracture (one trial, 1549 participants). There is also moderate-certainty evidence for women undergoing caesarean sections (one trial, 876 participants) and people having surgery for lower limb fractures (one trial, 1549 participants) that there is probably little difference in quality of life scores at 30 days or 3 or 6 months, respectively. Cost-effectiveness Five economic studies, based wholly or partially on trials included in our review, assessed the cost-effectiveness of NPWT compared with standard care. They considered NPWT in four indications: caesarean sections in obese women; surgery for lower limb fracture; knee/hip arthroplasty and coronary artery bypass graft surgery. They calculated quality-adjusted life-years for treatment groups and produced estimates of the treatments' relative cost-effectiveness. The reporting quality was good but the grade of the evidence varied from moderate to very low. There is moderate-certainty evidence that NPWT in surgery for lower limb fracture was not cost-effective at any threshold of willingness-to-pay and that NPWT is probably cost-effective in obese women undergoing caesarean section. Other studies found low or very low-certainty evidence indicating that NPWT may be cost-effective for the indications assessed.

AUTHORS' CONCLUSIONS

People experiencing primary wound closure of their surgical wound and treated prophylactically with NPWT following surgery probably experience fewer SSI than people treated with standard dressings (moderate-certainty evidence). There is no clear difference in number of deaths or wound dehiscence between people treated with NPWT and standard dressings (low-certainty evidence). There are also no clear differences in secondary outcomes where all evidence was low or very low-certainty. In caesarean section in obese women and surgery for lower limb fracture, there is probably little difference in quality of life scores (moderate-certainty evidence). Most evidence on pain is very low-certainty, but there is probably no difference in pain between NPWT and standard dressings after surgery for lower limb fracture (moderate-certainty evidence). Assessments of cost-effectiveness of NPWT produced differing results in different indications. There is a large number of ongoing studies, the results of which may change the findings of this review. Decisions about use of NPWT should take into account surgical indication and setting and consider evidence for all outcomes.

EWMA Document: Negative Pressure Wound Therapy

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

Negative pressure wound therapy for surgical wounds healing by primary closure

BACKGROUND

Indications for the use of negative pressure wound therapy (NPWT) are broad and include prophylaxis for surgical site infections (SSIs). While existing evidence for the effectiveness of NPWT remains uncertain, new trials necessitated an updated review of the evidence for the effects of NPWT on postoperative wounds healing by primary closure.

OBJECTIVES

To assess the effects of negative pressure wound therapy for preventing surgical site infection in wounds healing through primary closure.

SEARCH METHODS

We searched the Cochrane Wounds Specialised Register, CENTRAL, Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, and EBSCO CINAHL Plus in February 2018. We also searched clinical trials registries for ongoing and unpublished studies, and checked reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports to identify additional studies. There were no restrictions on language, publication date, or setting.

SELECTION CRITERIA

We included trials if they allocated participants to treatment randomly and compared NPWT with any other type of wound dressing, or compared one type of NPWT with another type of NPWT.

DATA COLLECTION AND ANALYSIS

Four review authors independently assessed trials using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and quality assessment according to GRADE methodology.

MAIN RESULTS

In this second update we added 25 intervention trials, resulting in a total of 30 intervention trials (2957 participants), and two economic studies nested in trials. Surgeries included abdominal and colorectal (n = 5); caesarean section (n = 5); knee or hip arthroplasties (n = 5); groin surgery (n = 5); fractures (n = 5); laparotomy (n = 1); vascular surgery (n = 1); sternotomy (n = 1); breast reduction mammoplasty (n = 1); and mixed (n = 1). In three key domains four studies were at low risk of bias; six studies were at high risk of bias; and 20 studies were at unclear risk of bias. We judged the evidence to be of low or very low certainty for all outcomes, downgrading the level of the evidence on the basis of risk of bias and imprecision.Primary outcomesThree studies reported mortality (416 participants; follow-up 30 to 90 days or unspecified). It is uncertain whether NPWT has an impact on risk of death compared with standard dressings (risk ratio (RR) 0.63, 95% confidence interval (CI) 0.25 to 1.56; very low-certainty evidence, downgraded once for serious risk of bias and twice for very serious imprecision).Twenty-five studies reported on SSI. The evidence from 23 studies (2533 participants; 2547 wounds; follow-up 30 days to 12 months or unspecified) showed that NPWT may reduce the rate of SSIs (RR 0.67, 95% CI 0.53 to 0.85; low-certainty evidence, downgraded twice for very serious risk of bias).Fourteen studies reported dehiscence. We combined results from 12 studies (1507 wounds; 1475 participants; follow-up 30 days to an average of 113 days or unspecified) that compared NPWT with standard dressings. It is uncertain whether NPWT reduces the risk of wound dehiscence compared with standard dressings (RR 0.80, 95% CI 0.55 to 1.18; very low-certainty evidence, downgraded twice for very serious risk of bias and once for serious imprecision).Secondary outcomesWe are uncertain whether NPWT increases or decreases reoperation rates when compared with a standard dressing (RR 1.09, 95% CI 0.73 to 1.63; 6 trials; 1021 participants; very low-certainty evidence, downgraded for very serious risk of bias and serious imprecision) or if there is any clinical benefit associated with NPWT for reducing wound-related readmission to hospital within 30 days (RR 0.86, 95% CI 0.47 to 1.57; 7 studies; 1271 participants; very low-certainty evidence, downgraded for very serious risk of bias and serious imprecision). It is also uncertain whether NPWT reduces incidence of seroma compared with standard dressings (RR 0.67, 95% CI 0.45 to 1.00; 6 studies; 568 participants; very low-certainty evidence, downgraded twice for very serious risk of bias and once for serious imprecision). It is uncertain if NPWT reduces or increases the risk of haematoma when compared with a standard dressing (RR 1.05, 95% CI 0.32 to 3.42; 6 trials; 831 participants; very low-certainty evidence, downgraded twice for very serious risk of bias and twice for very serious imprecision. It is uncertain if there is a higher risk of developing blisters when NPWT is compared with a standard dressing (RR 6.64, 95% CI 3.16 to 13.95; 6 studies; 597 participants; very low-certainty evidence, downgraded twice for very serious risk of bias and twice for very serious imprecision).Quality of life was not reported separately by group but was used in two economic evaluations to calculate quality-adjusted life years (QALYs). There was no clear difference in incremental QALYs for NPWT relative to standard dressing when results from the two trials were combined (mean difference 0.00, 95% CI -0.00 to 0.00; moderate-certainty evidence).One trial concluded that NPWT may be more cost-effective than standard care, estimating an incremental cost-effectiveness ratio (ICER) value of GBP 20.65 per QALY gained. A second cost-effectiveness study estimated that when compared with standard dressings NPWT was cost saving and improved QALYs. We rated the overall quality of the reports as very good; we did not grade the evidence beyond this as it was based on modelling assumptions.

AUTHORS' CONCLUSIONS

Despite the addition of 25 trials, results are consistent with our earlier review, with the evidence judged to be of low or very low certainty for all outcomes. Consequently, uncertainty remains about whether NPWT compared with a standard dressing reduces or increases the incidence of important outcomes such as mortality, dehiscence, seroma, or if it increases costs. Given the cost and widespread use of NPWT for SSI prophylaxis, there is an urgent need for larger, well-designed and well-conducted trials to evaluate the effects of newer NPWT products designed for use on clean, closed surgical incisions. Such trials should initially focus on wounds that may be difficult to heal, such as sternal wounds or incisions on obese patients.

Negative-Pressure Wound Therapy in Infants and Children: A Population-Based Study

BACKGROUND

Although the safety and benefits of negative-pressure wound therapy (NPWT) have been clearly demonstrated in the adult population, studies evaluating the safety and describing the use of NPWT in the pediatric population have been limited. Given this paucity, the goals of this study were to (1) evaluate the literature dedicated to NPWT use in infants and children and (2) leverage a population-level analysis to describe the experience of NPWT use in the pediatric population.

MATERIALS AND METHODS

We performed a literature review and analyzed the Truven Health Analytics MarketScan Commercial Claims Databases from 2006 to 2014 to identify infants and children treated with NPWT. We evaluated patient characteristics, indications, complications before and after NPWT placement, and health care utilization within 30 d of NPWT placement.

RESULTS

We identified 457 articles, 11 of which fit our inclusion criteria. Most studies (65.2%) were case reports or series with less than 10 patients. In addition, we identified 3184 patients aged younger than of 18 y who were treated with NPWT between 2006 and 2014. Serious incident complications within 30 d after NPWT placement were rare (bleeding 0.6%, septicemia 0.5%, and sepsis 0.5%).

CONCLUSIONS

Despite the lack of robust studies, NPWT is widely used for many indications and across different ages and providers. Given the low incidence of serious complications, we conclude that NPWT use in infants and children is safe and can be effectively used by different providers spanning surgical and nonsurgical disciplines.

Continuous Negative Pressure Drain is Associated with Better Outcome: A Randomized Prospective Trial in Plastic Surgery Patients

BACKGROUND

A randomized prospective trial to compare the effects on minimizing complications using continuous negative pressure drain and intermittent suction mode in plastic surgeries.

METHODS

There were 174 cases of stage II post-auricular flap expansion and ear reconstruction, 76 cases of skin expansion flap repair, 56 cases of breast augmentation surgery, 58 cases of abdominoplasty, and 76 cases with free skin grafts. Patients were randomized to intermittent suction mode group (control group) and continuous negative pressure external drain group (intervention group) stratified by surgery types. In the intervention group, different pressure levels were applied according to the surgery types. The drainage volume, the length of time of external drainage, incidence of seroma, flap necrosis, the first intending healing rate and drain-associated bleeding were recorded and compared.

RESULTS

Generally, fewer complications and better healing were observed in the intervention group. In patients with stage II post-auricular flap expansion and ear reconstruction, lower incidence of flap necrosis and seroma, higher first intention healing rate, greater drain volume but shorter time of drainage were observed in the intervention group (p < 0.05 for all). Similar results were shown in patients with skin expansion flap repair, breast augmentation, abdominoplasty, and free skin grafts. In patients who underwent free skin grafts, a higher graft success rate and lower graft infection rate were also observed (p < 0.01 for both). No drain-associated bleeding was observed.

CONCLUSIONS

A continuous negative pressure drain was associated with better outcomes in patients underwent various plastic surgeries and is a powerful technique in the postoperative management of plastic surgery.

LEVEL OF EVIDENCE II

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 .

Advances in managing the noninfected open chest after cardiac surgery: Negative-pressure wound therapy

OBJECTIVE

The objective of this study was to compare safety and clinical effectiveness of negative-pressure wound therapy (NPWT) with traditional wound therapy for managing noninfected open chests with delayed sternal closure after cardiac surgery.

METHODS

From January 2000 to July 2015, 452 of 47,325 patients who underwent full sternotomy left the operating room with a noninfected open chest (0.96%), managed using NPWT in 214-with frequency of use rapidly increasing to near 100%-and traditionally in 238. Predominant indications for open-chest management were uncontrolled coagulopathy or hemodynamic compromise on attempted chest closure. Weighted propensity-score matching was used to assess in-hospital complications and time-related survival.

RESULTS

NPWT and traditionally managed patients had similar high-risk preoperative profiles. Most underwent reoperations (63% of the NPWT group and 57% of the traditional group), and 21% versus 25% were emergency procedures. Reexplorations for bleeding were less common with NPWT versus traditional wound therapy (n = 63 [29%] vs 104 [44%], P = .002). Median duration of open-chest to definitive sternal closure was 3.5 days for NPWT versus 3.1 for traditionally managed patients (P[log rank] = .07). Seven patients (3.3%) were converted from NPWT to traditional therapy because of hemodynamic intolerance and 6 (2.5%) from traditional to NPWT. No NPWT-related cardiovascular injuries occurred. Among matched patients, NPWT was associated with better early survival (61% vs 44% at 6 months; P = .02).

CONCLUSIONS

NPWT is safe and effective for managing noninfected open chests after cardiac surgery. By facilitating open-chest management and potentially improving outcomes, it has become our therapy of choice and perhaps has lowered our threshold for leaving the chest open after cardiac surgery.

From open packing to negative wound pressure therapy: A critical overview of deep sternal wound infection treatment strategies after cardiac surgery

Deep sternal wound infection is a challenging aspect of modern cardiac surgery. The considerable mortality rate, devastating morbidity and, negative impact on long-term survival has driven cardiac and plastic surgeons to seek a more advantageous treatment solution. This review summarizes progress in the field of deep sternal wound infection treatment after cardiac surgery. Emphasis is placed on outcomes analysis of contemporary treatment strategy based on negative pressure wound therapy followed by sternotomy wound reconstruction, and its comparison with conventional treatment modalities used afore. Furthermore, complications and drawbacks of treatment strategies are critically evaluated to outline current options for successfully managing this life-threatening complication following cardiac surgery.

Efficacy of a novel strategy for poststernotomy deep sternal infection after thoracic aorta replacement using a prosthetic graft

BACKGROUND

Poststernotomy deep sternal wound infections are persistent and occasionally fatal, especially in cases involving prosthetic grafts, because of their complicated structure and virtual impossibility of removal. We aimed to verify the influence of cooperation with plastic surgeons and our novel strategy for treating deep sternal wound infection after aortic replacement on cardiovascular surgery outcomes.

PATIENTS AND METHODS

Nine hundred eighty-three consecutive patients were divided into two groups: an early group (2012-2013) and a late group (2014-2015). The late group had received cooperatively improved perioperative wound management: our novel strategy of deep sternal infection based on radical debridement and immediate reconstruction decided by reference to severities of the patient's general condition and widespread infection by early intervention of plastic surgeons. The groups were analysed retrospectively. Binary variables were analysed statistically with the Fisher exact test and continuous variables with the Mann-Whitney U test. Inter-group differences were assessed with the chi-square test.

RESULTS

Twenty of 390 cases in the early group and 13 of 593 cases in the late group were associated with deep sternal infection. Morbidity rates of deep sternal wound infection and associated mortality rates 1 year after reconstruction surgery were significantly less (p <0.05 for both) in the late group.

CONCLUSIONS

Intervention by plastic surgeons improved perioperative wound management outcomes. Our treatment strategy for deep sternal wound infection also reduced associated mortality rates. Facilities should consider the early inclusion of plastic surgeons in the treatment of patients undergoing aortic replacement to facilitate better outcomes.

MODIFIED VAC DRESSING IN STERNAL WOUND INFECTION MANAGEMENT. CHEAP AND FEASIBLE TECHNIQUE IN DEVELOPING COUNTRY

Sternal wound infection is a rare but serious complication of cardiac surgery leading to prolonged hospital stay and higher mortality. In the last decades several treatment modalities have been described, of which vacuum-assisted closure (VAC) shows the most promising results. However, the VAC therapy system is expensive, requires extensive amounts of product and needs a power source at all times. Modified VAC dressing to treat sternal wound infection is cheap and feasible technique to use in develop country. This technique can be use as an alternative to the original vacuum-assisted closure and hadshown to serve its function in providing adequatevacuum pressure for wounds.

Negative Pressure Wound Therapy in the Management of Combat Wounds: A Critical Review

Significance: Wounds sustained in a combat trauma often result in a composite tissue loss. Combat injuries, due to high energy transfer to tissues, lead to trauma at multiple anatomical sites. An early wound cover is associated with lower rate of infections and a faster wound healing. The concept of negative pressure wound therapy (NPWT) in the management of combat-related wounds has evolved from the civilian trauma and the wounds from nontraumatic etiologies. Recent Advances: Encouraged by the results of NPWT in noncombat-related wounds, the military surgeons during Operation Iraqi Freedom and Operation Enduring Freedom used this novel method in a large percentage of combat wounds, with gratifying results. The mechanism of NPWT in wound healing is multifactorial and often complex reconstructive procedure can be avoided in a combat trauma setting. Critical Issues: Wounds sustained in military trauma are heavily contaminated with dirt, patient clothing, and frequently associated with extensive soft tissue loss and osseous destruction. Delay in evacuation during an ongoing conflict carries the risk of systemic infection. Early debridement is indicated followed by delayed closure of wounds. NPWT helps to provide temporary wound cover during the interim period of debridement and wound closure. Future Directions: Future area of research in combat wounds is related to abdominal trauma with loss of abdominal wall. The concept of negative pressure incisional management system in patients with a high risk of wound breakdown following surgery is under review, and may be of relevance in combat wounds.

Effect of negative pressure wound therapy followed by tissue flaps for deep sternal wound infection after cardiovascular surgery: propensity score matching analysis

OBJECTIVES

Deep sternal wound infection (DSWI) after cardiovascular surgery via median sternotomy remains a severe complication associated with a drastic decrease in the quality of life. We assessed the risk factors for in-hospital death caused by DSWI and the available treatments for DSWI.

METHODS

Between January 1991 and August 2015, we retrospectively reviewed 73 patients (51 males and 22 females, mean age 67.5 ± 10.3 years) who developed DSWI after cardiovascular surgery via median sternotomy. Pathogenic bacteria mainly comprised methicillin-resistant Staphylococcus aureus (MRSA) (49.3%). Fifteen patients (20.5%) died in hospital with DSWI. Treatment of DSWI consisted of open daily irrigation (up to 2006) or negative pressure wound therapy (NPWT) (2007 onwards), followed by primary closure or reconstruction of tissue flaps. We assessed the risk factors for in-hospital mortality from DSWI by comparing data from the 15 patients who died and the 58 survivors using propensity score matching analysis of the treatments used for DSWI.

RESULTS

Univariate analysis identified age, use of intra-aortic balloon pumping, prolonged mechanical ventilation, tracheotomy, prolonged intensive care unit stay, postoperative low output syndrome, postoperative myocardial infarction, postoperative renal failure, postoperative use of haemodialysis, postoperative pneumonia, postoperative cerebral disorder, MRSA infection, NPWT and tissue flaps as being associated with in-hospital mortality (P < 0.05). Multivariate analysis identified NPWT (odds ratio, 0.062; 95% confidence interval, 0.004-0.897; P = 0.041) and tissue flaps (odds ratio, 0.022; 95% confidence interval, 0.000-0.960; P = 0.048) as independently associated with reduced in-hospital mortality after DSWI. On comparing 22 patients receiving NPWT with 22 not on NPWT using propensity score matching, patients on NPWT had significantly lower in-hospital mortality than those without NPWT (NPWT vs non-NPWT, 5 vs 36%, P = 0.021). In DSWI infected by MRSA, NPWT significantly reduced the in-hospital mortality caused by DSWI (NPWT vs non-NPWT, 0 vs 52%, P = 0.003).

CONCLUSIONS

NPWT and tissue flaps may be favourable factors associated with reduced in-hospital mortality attributable to DSWI. NPWT as a bridge therapy to tissue flaps may play a major role in treating DSWI and improve the prognosis for patients with MRSA-infected DSWI.

Pseudoaneurysm of the Right Internal Mammary Artery Post Vacuum-Assisted Closure Therapy: A Rare Complication and Literature Review

Vacuum-assisted closure (VAC) therapy in the management of sternal wound infection post cardiac surgery has gained popularity since last decade. It is very cost effective and has survival benefit compared with conventional management. Although there are few complications associated with VAC therapy including right ventricular free wall rupture and infectious erosion to aorta, there are now isolated reports of vein graft pseudoaneurysm associated with it. We describe an extremely rare complication of right internal mammary artery pseudoaneurysm post VAC therapy in a 56-year-old man which was successfully managed surgically. We also did a literature review on the possible complications of VAC therapy post cardiac surgery and its management.

Negative pressure wound therapy for skin grafts and surgical wounds healing by primary intention

BACKGROUND

Indications for the use of negative pressure wound therapy (NPWT) are broadening with a range of systems now available on the market, including those designed for use on clean, closed incisions and skin grafts. Reviews have concluded that the evidence for the effectiveness of NPWT remains uncertain, however, it is a rapidly evolving therapy. Consequently, an updated systematic review of the evidence for the effects of NPWT on postoperative wounds expected to heal by primary intention is required.

OBJECTIVES

To assess the effects of NPWT on surgical wounds (primary closure, skin grafting or flap closure) that are expected to heal by primary intention.

SEARCH METHODS

We searched the following electronic databases to identify reports of relevant randomised clinical trials: the Cochrane Wounds Group Specialised Register (searched 28 January 2014); the Cochrane Central Register of Controlled Trials (CENTRAL; 2013, issue 12); Database of Abstracts of Reviews of Effects (2013, issue 12); Ovid MEDLINE (2011 to January 2014); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 24 January 2014); Ovid EMBASE (2011 to January 2014 Week 44); and EBSCO CINAHL (2011 to January 2014). We conducted a separate search to identify economic evaluations.

SELECTION CRITERIA

We included trials if they allocated patients to treatment randomly and compared NPWT with any other type of wound dressing, or compared one type of NPWT with a different type of NPWT.

DATA COLLECTION AND ANALYSIS

We assessed trials for their appropriateness for inclusion and for their quality. This was done by three review authors working independently, using pre-determined inclusion and quality criteria.

MAIN RESULTS

In this first update, we included an additional four trials, taking the total number of trials included to nine (785 participants). Three trials involved skin grafts, four included orthopaedic patients and two included general surgery and trauma surgery patients; all the included trials had unclear or high risk of bias for one or more of the quality indicators we assessed. Seven trials compared NPWT with a standard dressing (two of these were 'home-made' NPWT devices), one trial compared one 'home-made' NPWT with a commercially available device. In trials where the individual was the unit of randomisation, there were no differences in the incidence of surgical site infections (SSI); wound dehiscence, re-operation (in incisional wounds); seroma/haematoma; or failed skin grafts. Lower re-operation rates were observed among skin graft patients in the 'home-made' NPWT group (7/65; 10.8%) compared to the standard dressing group (17/66; 25.8%) (risk ratio (RR) 0.42; 95% CI 0.19 to 0.92). The mean cost to supply equipment for VAC® therapy was USD 96.51/day compared to USD 4.22/day for one of the 'home-made' devices (P value 0.01); labour costs for dressing changes were similar for both treatments. Pain intensity score was also reported to be lower in the 'home-made' group when compared with the VAC® group (P value 0.02). One of the trials in orthopaedic patients was stopped early because of a high incidence of fracture blisters in the NPWT group (15/24; 62.5%) compared with the standard dressing group (3/36; 8.3%) (RR 7.50; 95% CI 2.43 to 23.14).

AUTHORS' CONCLUSIONS

Evidence for the effects of negative pressure wound therapy (NPWT) for reducing SSI and wound dehiscence remains unclear, as does the effect of NPWT on time to complete healing. Rates of graft loss may be lower when NPWT is used, but hospital-designed and built products are as effective in this area as commercial applications. There are clear cost benefits when non-commercial systems are used to create the negative pressure required for wound therapy, with no evidence of a negative effect on clinical outcome. In one study, pain levels were also rated lower when a 'home-made' system was compared with a commercial counterpart. The high incidence of blisters occurring when NPWT is used following orthopaedic surgery suggests that the therapy should be limited until safety in this population is established. Given the cost and widespread use of NPWT, there is an urgent need for suitably powered, high-quality trials to evaluate the effects of the newer NPWT products that are designed for use on clean, closed surgical incisions. Such trials should focus initially on wounds that may be difficult to heal, such as sternal wounds or incisions on obese patients.

The HeartShield device reduces the risk for right ventricular damage in patients with deep sternal wound infection

OBJECTIVE

Right ventricular rupture, resulting in serious bleeding, is a life-threatening complication associated with negative-pressure wound therapy (NPWT) in cardiac surgery. The use of a rigid barrier between the heart and the sharp sternal edges has been successfully tested on pigs. In the present article, we demonstrate increased safety in NPWT through the use of the HeartShield device.

METHODS

Six patients were treated with a specially designed device in combination with NPWT. The device consists of a horizontally placed disk covered in foam. The back of the T-shaped device sticks up between the sternal edges and up above skin level. This part of the device is also covered in foam. Drainage is performed through two holes at the top of the device. The device and foam are changed every second to third day, and -120 mm Hg of continuous therapy is used. Six patients were treated with traditional NPWT, serving as control group.

RESULTS

No signs of calluslike formation were seen on the right ventricle in the group treated with the HeartShield device. In the conventional NPWT control group, all six patients had calluslike formation (>1 × 2 cm2) on the anterior part of the right ventricle. All patients in the HeartShield group had grade 1 epicardial petechial bleeding (<0.5 cm2) on the right ventricle. In the control group, one patient had grade 1 (<0.5 cm2), three patients had grade 2 (0.5-2.0 cm2), and two patients had grade 3 (>2.0 cm2) epicardial petechial bleeding on the right ventricle. No major bleeding or mortality was observed in either group during the course of the study.

CONCLUSIONS

The use of the HeartShield device significantly minimizes the contact between the right ventricle and the sternal edges, thereby decreasing the risk for life-threatening complications due to bleeding.

Late presentation of a deep sternal wound infection and left breast abscess

In this paper, we present a case review of a 58-year-old female who presented to our emergency department with pyrexia, dyspnoea, dehydration and pain in her left breast six months following coronary artery bypass grafting (CABG). Although her sternotomy wound had healed well, examination revealed fluctuance of the whole precordium and left breast. She underwent antibiotic treatment and subsequent surgical debridement, followed by the application of vacuum-assisted dressings. Surgical reconstruction was deemed unsuitable and therefore the patient continued to be managed with vacuum dressings followed by routine dressings to allow the wound to heal by secondary intention. The patient was discharged three months after initial presentation in a good condition. The wound had completely healed four months later.

Vacuum-assisted closure system in treatment of postoperative mediastinitis

Objectives

Post-cardiac surgery mediastinitis is a serious complication with high morbidity and high financial costs. Using a vacuum-assisted closure system is the established line of treatment for mediastinitis, which improves outcome, especially in the high-risk group of patients.

Methods

From January 2007 to April 2011, a retrospective study was carried out to evaluate the outcome of vacuum-assisted closure in the treatment of postoperative mediastinitis.

Results

There were 34 patients; 27 were male and 7 female. Mean time from infection to vacuum-assisted closure was 3.34 ± 1.10 days. The duration of vacuum-assisted closure was 6.51 ± 1.85 days (3-9 days). The mean amount of discharge was 759.60 ± 175.28 mL (range, 354–990 mL). Of the 34 patients, 21 (61.76%) had direct surgical wound closure and 13 (41.16%) had re-wiring. Two patients had bilateral pectoral flaps. One patient had chronic fistula formation, and one had a tear in the right ventricle. Mean hospital stay was 11.28 ± 2.09 days (range, 6–16 days).

Conclusion

Vacuum-assisted closure therapy is a safe, reliable, and cost-effective modality of treatment for postoperative mediastinitis. It improves the outcome and can be combined with other modalities of conventional treatment, especially in high-risk groups such as the elderly or patients with diabetes.

A rigid disc for protection of exposed blood vessels during negative pressure wound therapy

BACKGROUND

There are increasing reports of serious complications and deaths associated with negative pressure wound therapy (NPWT). Bleeding may occur when NPWT is applied to a wound with exposed blood vessels. Inserting a rigid disc in the wound may protect these structures. The authors examined the effects of rigid discs on wound bed tissue pressure and blood flow through a large blood vessel in the wound bed during NPWT.

METHODS

Wounds were created over the femoral artery in the groin of 8 pigs. Rigid discs were inserted. Wound bed pressures and arterial blood flow were measured during NPWT.

RESULTS

Pressure transduction to the wound bed was similar for control wounds and wounds with discs. Blood flow through the femoral artery decreased in control wounds. When a disc was inserted, the blood flow was restored.

CONCLUSIONS

NPWT causes hypoperfusion in the wound bed tissue, presumably as a result of mechanical deformation. The insertion of a rigid barrier alleviates this effect and restores blood flow.

Negative pressure wound therapy for skin grafts and surgical wounds healing by primary intention

BACKGROUND

Indications for the use of negative pressure wound therapy (NPWT) are broadening with a range of systems on the market, including those designed for use on clean, closed incisions and skin grafts. Reviews have concluded that the evidence for the effectiveness of NPWT remains uncertain. However, this is a rapidly evolving therapy. Consequently, a systematic review of the evidence for the effects of NPWT on postoperative wounds expected to heal by primary intention is required.

OBJECTIVES

To assess the effects of NPWT on surgical wounds (primary closure or skin grafting) that are expected to heal by primary intention.

SEARCH METHODS

We searched the following electronic databases to identify reports of relevant randomised clinical trials: the Cochrane Wounds Group Specialised Register (searched 11 November 2011); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 4); Database of Abstracts of Reviews of Effects (The Cochrane Library 2011, Issue 4); Ovid MEDLINE (2005 to October Week 4 2011); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 8 November 2011); Ovid EMBASE (2009 to 2011 Week 44); and EBSCO CINAHL (1982 to 04 November 2011). We conducted a separate search to identify economic evaluations.

SELECTION CRITERIA

We included trials if they allocated patients at random and compared NPWT with any other type of wound dressing or compared one type of NPWT with a different type of NPWT.

DATA COLLECTION AND ANALYSIS

We assessed trials for their appropriateness for inclusion and for their quality. This was done by three review authors working independently, using pre-determined inclusion and quality criteria.

MAIN RESULTS

We included five eligible trials with a total of 280 participants. Two trials involved skin grafts and three acute wounds. Only one of the five trials reported the proportion of wounds completely healed and in this study all wounds healed. All five studies reported adverse events. In the four trials that compared standard dressings with negative pressure wound therapy (NPWT) the adverse event rate was similar between groups (negative pressure 33/86; standard dressing 37/103); risk ratio (RR) 0.97 (95% confidence intervals (CI) 0.33 to 2.89). There was significant heterogeneity for this result, due to the high incidence of fracture blisters in the NPWT group in one trial. One trial (87 participants) compared a commercial negative pressure device VAC® system with a negative pressure system developed in the hospital (GSUC). The adverse event rate was lower in the GSUC group (VAC® 3/42; GSUC 0/45); the RR was 0.13 (95% CI 0.01 to 2.51). Results indicate uncertainty about the true effect of either method on adverse events. The mean cost to supply equipment for VAC® therapy was USD 96.51/day compared to USD 4.22/day for the GSUC therapy (P = 0.01). Labour costs for dressing changes were similar. Pain intensity score was also reported to be lower in the GSUC group when compared with the VAC® group (p = 0.02)

AUTHORS' CONCLUSIONS

Evidence for the effectiveness of NPWT on complete healing of wounds expected to heal by primary intention remains unclear. Rates of graft loss may be lower when NPWT is used; but evidence to date suggests that hospital-based products are as effective in this area as commercial applications. There are clear cost benefits when non-commercial systems are used to create the negative pressure required for wound therapy, with no reduction in clinical outcome. Pain levels are also rated lower when hospital systems are compared with their commercial counterparts. The high incidence of blisters occurring when NPWT is used following orthopaedic surgery suggests that the therapy should be limited until safety in this population is established. Given the cost and widespread use of NPWT, there is an urgent need for suitably powered, high-quality trials to evaluate the effects of the newer NPWT products that are designed for use on clean, closed surgical incisions. Such trials should focus initially on wounds that may be difficult to heal, such as sternal wounds or surgeries for obese patients.

Aortic erosion during negative pressure therapy in a pediatric heart transplant recipient

A happy-ending "series of unfortunate events" is reported of the successful emergency treatment of an erosion of the ascending aorta during negative pressure sternal wound therapy for a relapse of Berlin Heart driveline infection in a pediatric transplant recipient. Several key issues related to assist device-related infections and negative pressure complications are discussed in this peculiar setting.

Major bleeding during negative pressure wound/V.A.C.®--therapy for postsurgical deep sternal wound infection--a critical appraisal

Negative-pressure wound therapy, commercially known as vacuum-assisted closure (V.A.C.^®) therapy, has become one of the most popular (and efficacious) interim (prior to flap reconstruction) or definite methods of managing deep sternal wound infection. Complications such as profuse bleeding, which may occur during negative-pressure therapy but not necessarily due to it, are often attributed to a single factor and reported as such. However, despite the wealth of clinical experience internationally available, information regarding certain simple considerations is still lacking. Garnering information on all the factors that could possibly influence the outcome has become more difficult due to a (fortunate) decrease in the incidence of deep sternal wound infection. If more insight is to be gained from fewer clinical cases, then various potentially confounding factors should be fully disclosed before complications can be attributed to the technique itself or improvements to negative-pressure wound therapy for deep sternal wound infection can be accepted as evidence-based and the guidelines for its use adapted. The authors propose the adoption of a simple checklist in such cases.

The influence on wound contraction and fluid evacuation of a rigid disc inserted to protect exposed organs during negative pressure wound therapy

The use of a rigid disc as a barrier between the wound bed and the wound filler during negative pressure wound therapy (NPWT) has been suggested to prevent damage to exposed organs. However, it is important to determine that the effects of NPWT, such as wound contraction and fluid removal, are maintained during treatment despite the use of a barrier. This study was performed to examine the effect of NPWT on wound contraction and fluid evacuation in the presence of a rigid disc. Peripheral wounds were created on the backs of eight pigs. The wounds were filled with foam, and rigid discs of different designs were inserted between the wound bed and the foam. Wound contraction and fluid evacuation were measured after application of continuous NPWT at -80 mmHg. Wound contraction was similar in the presence and the absence of a rigid disc (84 ± 4% and 83 ± 3%, respectively, compared with baseline). Furthermore, the rigid disc did not affect wound fluid removal compared with ordinary NPWT (e.g. after 120 seconds, 71 ± 4 ml was removed in the presence and 73 ± 3 ml was removed in the absence of a disc). This study shows that a rigid barrier may be placed under the wound filler to protect exposed structures during NPWT without affecting wound contraction and fluid removal, which are two crucial features of NPWT.

Update on negative-pressure wound therapy

BACKGROUND

Over the last 15 years, negative-pressure wound therapy has become commonly used for treatment of a wide variety of complex wounds. There are now several systems marketed, and additional products will be available in the near future. Many clinicians have noted a dramatic response when negative-pressure wound therapy technology has been used, prompting a number of scientific investigations related to its mechanism of action and clinical trials determining its efficacy.

METHODS

The peer-reviewed literature within the past 5 years was reviewed, using an evidence-based approach.

RESULTS

Negative-pressure wound therapy works through mechanisms that include fluid removal, drawing the wound together, microdeformation, and moist wound healing. Several randomized clinical trials support the use of negative-pressure wound therapy in certain wound types. Serious complications, including bleeding and infection, have recently been reported by the U.S. Food and Drug Administration in a small number of patients.

CONCLUSIONS

Negative-pressure wound therapy has dramatically changed the way complex wounds are treated. The rapid introduction of this technology has occurred faster than large-scale randomized controlled studies or registry studies have been conducted. Further clinical studies and basic science studies will help surgeons to better understand the evidence and use this technology in the future.