The Impact of Deep Sternal Wound Infection on Mortality and Resource Utilization: A Population-based Study

Infectious Mediastinitis: A Retrospective Cohort Study

Background

This study aimed to characterize the demographics, microbiology, management and treatment outcomes of mediastinitis according to the origin of the infection.

Methods

This retrospective observational study enrolled patients who had mediastinitis diagnosed according to the criteria defined by the Centers for Disease Control and Prevention and were treated in Strasbourg University Hospital, France, between 1 January 2010 and 31 December 2020.

Results

We investigated 151 cases, including 63 cases of poststernotomy mediastinitis (PSM), 60 cases of mediastinitis due to esophageal perforation (MEP) and 17 cases of descending necrotizing mediastinitis (DNM). The mean patient age (standard deviation) was 63 (14.5) years, and 109 of 151 patients were male. Microbiological documentation varied according to the origin of the infection. When documented, PSM cases were mostly monomicrobial (36 of 53 cases [67.9%]) and involved staphylococci (36 of 53 [67.9%]), whereas MEP and DNM cases were mostly plurimicrobial (38 of 48 [79.2%] and 8 of 12 [66.7%], respectively) and involved digestive or oral flora microorganisms, respectively. The median duration of anti-infective treatment was 41 days (interquartile range, 21-56 days), and 122 of 151 patients (80.8%) benefited from early surgical management. The overall 1-year survival rate was estimated to be 64.8% (95% confidence interval, 56.6%-74.3%), but varied from 80.1% for DNM to 61.5% for MEP.

Conclusions

Mediastinitis represents a rare yet deadly infection. The present cohort study exhibited the different patterns observed according to the origin of the infection. Greater insight and knowledge on these differences may help guide the management of these complex infections, especially with respect to empirical anti-infective treatments.

How effective is simple mechanical wound debridement in reducing bacterial colonisation? Results of a prospective clinical study

BACKGROUND AND AIMS

Bacteria in wounds can lead to stagnation of wound healing as well as to local or even systemic wound infections up to potentially lethal sepsis. Consequently, the bacterial load should be reduced as part of wound treatment. Therefore, the efficacy of simple mechanical wound debridement should be investigated in terms of reducing bacterial colonisation.

PATIENTS AND METHODS

Patients with acute or chronic wounds were assessed for bacterial colonisation with a fluorescence camera before and after mechanical wound debridement with sterile cotton pads. If bacterial colonisation persisted, a second, targeted wound debridement was performed.

RESULTS

A total of 151 patients, 68 (45.0%) men and 83 (55.0%) women were included in this study. The male mean age was 71.0 years and the female 65.1 years. By establishing a new analysis method for the image files, we could document that the bacterial colonised areas were distributed 21.9% on the wound surfaces, 60.5% on the wound edges (up to 0.5 cm) and 17.6% on the wound surroundings (up to 1.5 cm). One mechanical debridement achieved a significant reduction of bacterial colonised areas by an average of 29.6% in the wounds, 18.9% in the wound edges and 11.8% in the wound surroundings and was increased by performing it a second time.

CONCLUSIONS

It has been shown that even a simple mechanical debridement with cotton pads can significantly reduce bacterial colonisation without relevant side effects. In particular, the wound edges were the areas that were often most contaminated with bacteria and should be included in the debridement with special attention. Since bacteria remain in wounds after mechanical debridement, it cannot replace antimicrobial therapy strategies, but offer a complementary strategy to improve wound care. Thus, it could be shown that simple mechanical debridement is effective in reducing bacterial load and should be integrated into a therapeutic approach to wounds whenever appropriate.

Liquid chromatography-tandem mass spectrometry methods for quantification of total and free antibiotic concentrations in serum and exudate from patients with post-sternotomy deep sternal wound infection receiving negative pressure wound therapy

BACKGROUND

Systemically administered antibiotics are thought to penetrate the wounds more effectively during negative pressure wound therapy (NPWT).To test this hypothesis total and free antibiotic concentrations were quantified in serum and wound exudate.

METHODS

UHPLC-MS/MS methods were developed and validated for the determination of ceftazidime, cefepime, cefotaxime, cefuroxime, cefazolin, meropenem, oxacillin, piperacillin with tazobactam, clindamycin, ciprofloxacin, sulfamethoxazole/trimethoprim (cotrimoxazole), gentamicin, vancomycin, and linezolid. The unbound antibiotic fraction was obtained by ultrafiltration using a Millipore Microcon-30kda Centrifugal Filter Unit. Analysis was performed on a 1.7-µm Acquity UPLC BEH C18 2.1 × 100-mm column with a gradient elution.

RESULTS

The validation was performed for serum, exudates and free fractions. For all matrices, requirements were met regarding linearity, precision, accuracy, limit of quantitation, and matrix effect. The coefficient of variation was in the range of 1.2-13.6%.and the recovery 87.6-115.6%, respectively. Among the 29 applications of antibiotics thus far, including vancomycin, clindamycin, ciprofloxacin, oxacillin, cefepime, cefotaxime, cotrimoxazole, and gentamicin, total and free antibiotic concentrations in serum and exudate were correlated.

CONCLUSION

This method can accurately quantify the total and free concentrations of 16 antibiotics. Comparison of concentration ratios between serum and exudates allows for monitoring individual antibiotics' penetration capacity in patients receiving NPWT.

The impact of two radical sternectomy surgical techniques on the outcome of deep sternal wound infections

BACKGROUND

Deep sternal wound infection (DSWI) is a rare, yet devastating complication after cardiac surgery. While the surgical treatment always implies the soft tissue and bone debridement, there is little data about this procedure. The aim of our study was to evaluate the impact of the radical sternectomy on the outcome in patients with DSWI and to identify the risk factors which could influence the result. The surgical techniques of piecemeal sternectomy and the newly developed en bloc sternectomy were also evaluated.

METHODS

The study was developed as a retrospective cohort study. 86 patients with DSWI who received a radical sternal resection at our institution between March 2018 and December 2021 were included.

RESULTS

The average age of the cohort was 67.3 ± 7.4 years, and 23.3% of patients were female. The average length of stay trended shorter after en bloc sternectomy (median 26 days) compared to piecemeal sternectomy (37 days). There were no significant differences between the piecemeal and en bloc sternal resection techniques. Anticoagulant and antiplatelet drugs had no significant influence on bleeding and transfusion rates. Obese patients showed an increased risk for postoperative bleeding requiring reintervention. Transfusion of packed red blood cells was significantly associated with lower hemoglobin values before surgery and ASA Class 4 compared to ASA Class 3. The in-hospital mortality was 9.3%, with female sex and reintervention for bleeding as significant risk factors. Nine patients developed an infection relapse as a chronic fistula at the level of clavicula or ribs, with ASA Class 4 as a risk factor.

CONCLUSION

Radical sternectomy is a safe procedure to treat DSWI with compromised sternal bone. Both piecemeal and en bloc techniques ensure reliable results, while complications and mortality appear to be patient-related.

Antibiotic therapy in reconstructive surgery of deep sternal wound infections

BACKGROUND

The choice of antibiotics and length of administration in the treatment of deep sternal wound infections (DSWI) is unclear. The reason for this is the lack of studies and local differences in resistance. An increase in resistance can be observed in gram-positive cocci, which are the most frequently detected in deep sternal infections. The duration of administration is often 2- 6 weeks or longer, although the benefit of prolonged antibiotic administration has not been confirmed by studies. We evaluated the antibiotic treatment during surgical treatment, consisting of surgical wound debridement and plastic chest reconstruction.

METHODS

Retrospective analysis of patients (n = 260) who underwent reconstructive surgery in the Department of Plastic Surgery at Leipzig University Hospital from 01.05.2012 - 31.12.2020. The duration of intake, results of microbiological swabs and resistance were investigated.

RESULTS

At the time of discharge, closed wound conditions were noted in 177 of 260 cases (68.1%). The largest proportion of patients (n = 238) was treated with a latissimus dorsi flap (91.5%).Antibiotic treatment was conducted in 206 of 260 cases (79.2%). The mean duration of antibiotic administration was 21.4 days (±17.6). Prolonged treatment over 14 days did not alter outcome (p = 0.226), in contrast, the number of multidrug resistances (p < 0.001). There was no prove of resistance against linezolid which is effective against the most common found infectious agents Staphylococcus epidermidis (n = 93; 24.0 %) & Staphylococcus aureus (n = 47; 12.1 %).

CONCLUSION

There is no evidence of benefit from antibiotic therapy over 14 days, whereas multidrug resistance increases with prolonged antibiotic use. In the absence of infectious agents or clinical signs of inflammation, surgical treatment without additional antibiotic treatment is effective.Linezolid is a suitable antibiotic in the treatment of gram-positive infections which are the most frequent in DSWI.

Temporal Cluster Analysis of Deep Sternal Wound Infection in a Regional Quality Collaborative

INTRODUCTION

Deep sternal wound infection (DSWI) is a rare complication associated with high mortality. Seasonal variability in surgical site infections has been demonstrated, however, these patterns have not been applied to DSWI. The purpose of this study was to assess temporal clustering of DSWIs.

METHODS

All cardiac surgery patients who underwent sternotomy were queried from a regional Society of Thoracic Surgeons database from 17 centers from 2001 to 2019. All patients with the diagnosis of DSWI were then identified. Cluster analysis was performed at varying time intervals (monthly, quarterly, and yearly) at the hospital and regional level. DSWI rates were calculated by year and month, and compared using mixed-effects negative binomial regression.

RESULTS

A total of 134,959 patients underwent a sternotomy for cardiac surgery, of whom 469 (0.35%) developed a DSWI. Rates of DSWI per hospital across all years ranged from 0.12% to 0.69%. Collaborative-level rates of DSWIs were the greatest in September (0.44%) and the lowest in January (0.30%). Temporal clustering was not seen across seasonal quarters (high rate in preceeding quarter was not associated with a high rate in the next quarter) (P = 0.39). There were yearly differences across all institutions in the DSWI rates. A downward trend in DSWI rates was seen from 2001 to 2019 (P < 0.001). A difference among hospitals in the cohort was observed (P < 0.001).

CONCLUSIONS

DSWI are a rare event within our region. Unlike other surgical site infection, there does not appear to be a seasonal pattern associated with DSWI.

The impact of COVID-19 prevention measures on surgical wound infection rates post-cardiac surgery

The COVID-19 pandemic had a huge impact on medical services. Several measures have been implemented to reduce the risk of viral transmission. In this paper, we assessed the impact of these measures on surgical wound infection rates in patients post-cardiac surgery. Hypothesis testing was used to compare post-cardiac operation infection rates between the year prior to the COVID-19 pandemic being declared and the first 13 months of the pandemic. The infection rates in 969 patients with operations between 01/03/2019 and 29/02/2020 were compared to those of 925 patients with cardiac surgery between 01/03/2020 and 31/03/2021. Infection rates for various operative urgencies and infection types were analysed. To compare infection rates, a two-tailed pooled z-test using the difference in infection proportions was performed. A 5% significance level was used and only categories with at least 10 patients in both the pre-covid and covid populations were tested. For leg infections, only operations involving coronary artery bypass grafting were included. To ensure that any differences in outcomes were not due to differences in patient demographics resulting in unequal operative risks, Euroscore II values, a measure of cardiac operative risk, were compared between the pre-covid and post-covid cohorts. The Mann-Whitney U-test was used to determine whether the distributions of Euroscore II values were likely to be drawn from the same population. A significance level of 5% was used. A total of 1901 patients (932 during the COVID-19 pandemic) were included in this study. Significant reduction in post-operative infections for all patients undergoing cardiac surgery from 4.3% of patients before COVID to 1.5% during the pandemic. During the pandemic, fewer elective and more urgent operations were performed. This study suggests a significant role of iatrogenic causes in wound infections prior to the pandemic. The implementation of COVID-19 prevention measures in healthcare providers can reduce surgical infection rates. As COVID-19-related restrictions have been eased, we suggest maintaining them in healthcare providers to reduce the incidence of surgical wound infections.

The Impact of Gender and Age in Obese Patients on Sternal Instability and Deep-Sternal-Wound-Healing Disorders after Median Sternotomy

OBJECTIVE

The aim of this study was to investigate the relationship between age and sex in regard to the development of deep sternal wound infections and sternal instability following median sternotomy.

METHODS

A propensity-score-matching analysis was conducted on 4505 patients who underwent cardiac surgery between 2009 and 2021, all of whom had a BMI of ≥30 kg/m². A total of 1297 matched pairs were determined in the sex group, and 1449 matched pairs we determined in the age group. The distributions of sex, age, diabetes mellitus, delirium, unstable sterna, wire refixation, wire removal, superficial vacuum-assisted wound closure, deep vacuum-assisted wound closure, clamp time, bypass time, logistic EuroSCORE, and BMI were determined.

RESULTS

The 30-day in-hospital mortality was found to be similar in the older and younger groups (8.149% vs. 8.35%, p = 0.947), and diabetes mellitus was also equally distributed in both groups. However, postoperative delirium occurred significantly more often in the older group (29.81% vs. 17.46%, p < 0.001), and there was a significantly higher incidence in men compared with women (16.96% vs. 26.91%, p < 0.001). There were no differences found in the incidence of sternum instability, fractured sternum, superficial vacuum-assisted wound closure, and deep vacuum-assisted wound closure between the age and sex groups.

CONCLUSIONS

In conclusion, this study found that sternal instability and deep-wound-healing problems occur with equal frequency in older and younger patients and in men and women following median sternotomy. However, the likelihood of postoperative delirium is significantly higher in older patients and in men. These findings suggest that a higher level of monitoring and care may be required for these high-risk patient groups to reduce the incidence of postoperative delirium and improve outcomes following median sternotomy.

Review on risk factors, classification, and treatment of sternal wound infection

Sternal wound infection (SWI) is the most common complication of the median sternal incision. The treatment time is long, and the reconstruction is difficult, which causes challenges for surgeons. Plastic surgeons were often involved too late in such clinical scenarios when previous empirical treatments failed and the wound damage was relatively serious. Accurate diagnosis and risk factors against sternal wound infection need to be in focus. Classification of different types of sternotomy complications post-cardiac surgery is important for specific categorization and management. Not familiar with this kind of special and complex wound, objectively increasing the difficulty of wound reconstruction. The purpose of this comprehensive review is to review the literature, introduce various SWI risk factors related to wound nonunion, various classification characteristics, advantages and disadvantages of various wound reconstruction strategies, to help clinicians understand the pathophysiological characteristics of the disease and choose a better treatment method.

Predictors of sternal wound infection post cardiac surgery in a Saudi Centre: a case control study

BACKGROUND

Sternal wound infection (SWI) post cardiac surgery remains an important cause of extra morbidity, mortality and cost. The objective was to identify risk factors for SWI in a cardiac centre in Eastern Saudi Arabia as part of the investigation into Surveillance variance in the local rates of SWI.

METHODS

We included cases and controls from a cross section of patients who underwent major cardiac surgery between 2017 and 2020 matched for age, sex and time of surgery. An explanatory logistic regression model was fitted to estimate the risk factors.

RESULTS

N = 204 (51 cases and 153 controls matching ratio 1:3, from a source population of 985 patients). factors significantly associated with SWI in the final multivariate model: hospital stay OR (1.05, Cl 1.01-1.10), Graft Conduit BIMA versus No Graft OR (10.94, Cl 1.60-74.63), transfusion of both packed cells plus other blood products versus no transfusion OR (3.53, Cl 93-13.44), HbA1c OR (1.09 Cl 0.84-1.41), BMI OR (1.25, Cl 1.04-1.50), perioperative blood glucose OR (1.02, Cl 1.004-1.03), surgery time OR (1.19, Cl 1.00-1.58).

CONCLUSIONS

The diverse aetiology, cross-disciplinary nature of SWI prevention, and despite improved prevention and control practices, including related care bundles with their proven value, SWI remain a serious challenge in cardiac surgery. Multidisciplinary consensus guidelines are well overdue.

Deep Sternal Wound Infection and Mortality in Cardiac Surgery: A Meta-analysis

BACKGROUND

Deep sternal wound infection (DSWI) is a rare but severe complication after cardiac surgical procedures and has been associated with increased early morbidity and mortality. Studies reporting long-term outcomes in patients with DSWI have shown contradictory results. We performed a study-level meta-analysis evaluating the impact of DSWI on short- and long-term clinical outcomes.

METHODS

A systematic literature search was conducted to identify studies comparing short- and long-term outcomes of patients submitted to cardiac surgical procedures who developed DSWI and patients who did not. The primary outcome was overall mortality. Secondary outcomes were in-hospital mortality, follow-up mortality, major adverse cardiovascular events, myocardial infarction, and repeat revascularization. Postoperative outcomes were also investigated.

RESULTS

Twenty-four studies totaling 407 829 patients were included. Overall, 6437 (1.6%) patients developed DSWI. Mean follow-up was 3.5 years. DSWI was associated with higher overall mortality (incidence rate ratio [IRR], 1.99; 95% CI, 1.66-2.38; P < .001), in-hospital mortality (odds ratio, 3.30; 95% CI, 1.88-5.81; P < .001), follow-up mortality (IRR, 2.02; 95% CI, 1.39-2.94; P = .001), and major adverse cardiovascular events (IRR, 2.04; 95% CI, 1.60-2.59; P < .001). No differences in myocardial infarction and repeat revascularization were found, but limited studies reported those outcomes. DSWI was associated with longer postoperative hospitalization, stroke, myocardial infarction, and respiratory and renal failure. Sensitivity analyses on isolated coronary artery bypass grafting studies and by adjustment method were consistent with the main analysis.

CONCLUSIONS

Compared with patients who did not develop DSWI, patients with DSWI after cardiac surgical procedures had increased risk of death as well as short- and long-term adverse clinical outcomes.

Combined pectoralis and rectus abdominis flaps are associated with improved outcomes in sternal reconstruction

BACKGROUND

Mortality increases nearly 5-fold in the approximately 5% of patients who develop sternal wound complications after cardiothoracic surgery. Flap-based reconstruction can improve outcomes by providing well-vascularized soft tissue for potential space obliteration, antibiotic delivery, and wound coverage; however, reoperation and readmission rates remain high. This study used the high case volume at a tertiary referral center and a diverse range of reconstructive approaches to compare various types of flap reconstruction. Combined (pectoralis and rectus abdominis) flap reconstruction is hypothesized to decrease sternal wound complication-related adverse outcomes.

METHODS

A retrospective cohort study of consecutive adult patients treated for cardiothoracic surgery sternal wound complications between 2008 and 2018 was performed. Patient demographics, comorbidities, wound characteristics, surgical parameters, and perioperative data were collected. Multivariable regression modeling with stepwise forward selection was used to characterize predictive factors for sternal wound-related readmissions and reoperations.

RESULTS

In total, 215 patients were assessed for sternal wound reconstruction. Patient mortality at 1 year was 12.4%. Flap selection was significantly associated with sternal wound-related readmissions (P = .017) and reoperations (P = .014). Multivariate regression demonstrated rectus abdominis flap reconstruction independently predicted increased readmissions (odds ratio 3.4, P = .008) and reoperations (odds ratio 2.9, P = .038). Combined pectoralis and rectus abdominis flap reconstruction independently predicted decreased readmissions overall (odds ratio 0.4, P = .031) and in the deep sternal wound subgroup (odds ratio 0.1, P = .033).

CONCLUSION

Although few factors can be modified in this complex highly comorbid population with a challenging and rare surgical problem, consideration of a more surgically aggressive multiflap reconstructive approach may be justified to improve outcomes.

Treatment of Complex Two-Vessel Coronary Heart Disease with Single Left Internal Mammary Artery as T-Graft with Itself—A Retrospective Double Center Analysis of Short-Term Outcomes

Background and Objectives: The strategy of revascularization may be constrained in patients with insufficient bypass grafts and with increased risk of wound healing disorders. Among those with complex left-sided double-vessel disease in whom a percutaneous coronary intervention (PCI), as well as the surgical procedure of minimally invasive coronary artery bypass grafting via left minithoracotomy (MICS CABG), is not a treatment option, CABG using the left internal mammary artery as a T-graft with itself may be an effective treatment strategy. Materials and Methods: We reviewed the data from patients treated in Cologne and Tuebingen from 2019 to 2022. We included 40 patients who received left internal mammary artery (LIMA) grafting, and additional T-graft with the LIMA itself. The objective was focused on intraoperative and short-term outcomes. Results: A total of 40 patients were treated with the LIMA-LIMA T-graft procedure with a Fowler score calculated at 20.1 ± 3.0. A total of 37.5% of all patients had lacking venous graft material due to prior vein stripping, and 21 patients presented severe vein varicosis. An overall of 2.6 ± 0.5 distal anastomoses (target vessels were left anterior descending, diagonal, intermediate branch, and/or left marginal ramus) were performed, partly sequentially. Mean flow of LIMA-Left anterior descending (LAD) anastomosis was 59.31 ± 11.04 mL/min with a mean PI of 1.21 ± 0.18. Mean flow of subsequent T-Graft accounted for 51.31 ± 3.81 mL/min with a mean PI of 1.39 ± 0.47. Median hospital stay was 6.2 (5.0; 7.5) days. No incidence of postoperative wound healing disorders was observed, and all patients were discharged. There was one 30-day readmission with a diagnosis of pericardial effusion (2.5%). There was no 30-day mortality within the cohort. Conclusions: Patients requiring surgical myocardial revascularization due to complex two-vessel coronary artery disease (CAD) can be easily managed with LIMA alone, despite an elevated Fowler score and a promising outcome. A prospective study needs to be conducted, as well as longer term surveillance, to substantiate and benchmark the long-term results, as well as the patency rates.

Free extended anterolateral thigh myocutaneous flap versus combined pedicled pectoralis major-latissimus dorsi myocutaneous flaps in deep and extensive sternal wound reconstruction

BACKGROUND

The combined pedicled pectoralis major-latissimus dorsi (PM-LD) and free extended anterolateral thigh (ALT) myocutaneous flaps provide well-vascularized tissues for extensive sternal wound reconstruction. However, the outcomes and postoperative complications between the two surgical techniques are different. Thus, the aim of this study is to evaluate the feasibility of these two reconstructive options.

METHODS

This single-center, retrospective study was conducted between August 2011 and May 2019. Forty-four patients diagnosed with deep sternal wound infection (DSWI) and presented with grade four complications (sternal instability and necrotic bone tissue) were enrolled. Two reconstructive strategies, namely, combined pedicled PM-LD (n = 24) and free extended ALT (n = 20) myocutaneous flaps, were used according to the patients' hemodynamics. Data including age, gender, body mass index (BMI), hospital stay, follow-up, defect/flap size, number of surgical procedures before reconstruction, duration from the last debridement to flap coverage, comorbidities, and postoperative complications, were obtained for statistical analysis.

RESULTS

The mean defect size in the combined PM-LD myocutaneous flap group was 188.4 (5*17-10*23) cm² , and the mean flap size was 150.0 (8*12-15*15) cm² and 205.0 (8*15-10*25) cm² in PM and LD flap, respectively. The mean defect size in the free extended ALT myocutaneus flap group was 202.5 (6*16-10*21) cm² , and the mean flap size was 285.2 (9*30-12*25) cm² . No significant differences were observed between the free extended ALT and the combined pedicled PM-LD myocutaneous flaps in relation to age, gender, BMI, hospital days, follow-up, defect size, preoperative procedures, and comorbidities, except for the average operative time (443.2 ± 31.2 vs. 321.3 ± 54.3 mins, p = .048). The combined pedicled PM-LD myocutaneous flap had significantly more donor site complications, including seroma (21% vs. 0%, p = .030), bilateral nipple-areolar complex asymmetry (100% vs. 0%, p < .0001), and skin graft loss with infection (33% vs. 0%; p = .044) than the free extended ALT myocutaneous flap.

CONCLUSION

The free extended ALT and the combined pedicled PM-LD myocutaneous flaps were both feasible and effective options for sternal wound reconstruction. Our findings suggested that the free extended ALT myocutaneous flap may be a better alternative for a comprehensive and extensive reconstruction of sternal wounds. Further studies based on these findings can be conducted.

Incisional Negative Pressure Wound Therapy Is Protective Against Postoperative Cardiothoracic Wound Infection

BACKGROUND

Sternal wound infections are a rare but life-threatening complication of cardiothoracic surgery. Prior literature has supported the use of negative pressure wound therapy to decrease sternal wound infections and promote healing. This study sought to determine whether closed incision negative pressure therapy reduced wound infection and improved outcomes in cardiothoracic surgery.

METHODS

A retrospective cohort study was performed including all adult patients who underwent nontraumatic cardiothoracic surgery at a single institution between 2016 and 2018 (n = 1199). Patient characteristics, clinical variables, and surgical outcomes were compared between those who did and did not receive incisional negative pressure wound therapy intraoperatively. Multivariable logistic regression analysis determined factors predictive or protective of the development of complications.

RESULTS

Incisional negative pressure wound therapy was used in 58.9% of patients. Patients who received this therapy were older with statistically higher rates of hyperlipidemia, statin, and antihypertensive use. The use of negative pressure wound therapy was found to significantly reduce rates of both wound infection (3.0% vs 6.3%, P = 0.01) and readmission for wound infection (0.7% vs 2.6%, P = 0.01). After controlling for confounding variables, negative pressure wound therapy was found to be a protective factor of surgical wound infection (odds ratio, 0.497; 95% confidence interval, 0.262-0.945).

CONCLUSIONS

In the largest population studied to date, this study supported the expanded use of negative pressure therapy on sternal wound incisions to decrease infection rates.

An Algorithmic Approach to the Surgical Management of Sternal Dehiscence: A Single-Center Experience

Background Deep sternal wound complications following sternotomy represent a complex challenge. Management can involve debridement, flap reconstruction, and rigid sternal fixation (RSF). We present our 11-year experience in the surgical treatment of deep sternal wound dehiscence using a standardized treatment algorithm.

Methods A retrospective review was conducted of all 134 cardiac patients who required operative debridement after median sternotomy at a single institution between October 2007 and March 2019. Demographics, perioperative covariates, and outcomes were recorded. Univariate and subgroup analyses were performed.

Results One-hundred twelve patients (83.5%) with a deep sternal dehiscence underwent flap closure and 56 (50%) RSF. Of the patients who underwent flap closure, 87.5% received pectoralis advancement flaps. A 30-day mortality following reconstruction was 3.9%. Median length of stay after initial debridement was 8 days (interquartile range: 5–15). Of patients with flaps, 54 (48%) required multiple debridements prior to closure, and 30 (27%) underwent reoperation after flap closure. Patients who needed only a single debridement were significantly less likely to have a complication requiring reoperation (N = 10/58 vs. 20/54, 17 vs. 37%, p = 0.02), undergo a second flap (N = 6/58 vs. 17/54, 10 vs. 32%, p < 0.001), or, if plated, require removal of sternal plates (N = 6/34 vs. 11/22, 18 vs. 50%, p = 0.02).

Conclusion Although sternal dehiscence remains a complex challenge, an aggressive treatment algorithm, including debridement, flap closure, and consideration of RSF, can achieve good long-term outcomes. In low-risk patients, RSF does not appear to increase the likelihood of reoperation. We hypothesize that earlier surgical intervention, before the development of systemic symptoms, may be associated with improved outcomes.

Association between sternal wound complications and 10-year mortality following coronary artery bypass grafting

OBJECTIVE

To evaluate the association between sternal wound complications (SWC) and long-term mortality in the Arterial Revascularization Trial.

METHODS

Participants in the Arterial Revascularization Trial were stratified according to the occurrence of postoperative SWC. The primary outcome was all-cause mortality at long-term follow-up. The secondary outcome was major adverse cardiovascular events.

RESULTS

Three thousand one hundred two patients were included in the analysis; the median follow-up was 10 years. 115 patients (3.7%) had postoperative SWC: 85 (73.9%) deep sternal wound infections and 30 (26.1%) sterile SWC that required sternal reconstruction. Independent predictors of SWC included diabetes (odds ratio [OR], 2.77; 95% CI, 1.79-4.30; P < .001), female sex (OR, 2.73; 95% CI, 1.71-4.38; P < .001), prior stroke (OR, 2.59; 95% CI, 1.12-5.98; P = .03), chronic obstructive pulmonary disease (OR, 2.44; 95% CI, 1.60-3.71; P < .001), and use of bilateral internal thoracic artery (OR, 1.70; 95% CI, 1.12-2.59; P = .01). Postoperative SWC was significantly associated with long-term mortality. The Kaplan-Meier survival estimate was 91.3% at 5 years and 79.4% at 10 years in patients without SWC, and 86.1% and 64.3% in patients with SWC (log rank P < .001). The rate of major adverse cardiovascular events was also higher among patients who had SWC (n = 51 [44.3%] vs 758 [25.4%]; P < .001). Using multivariable analysis, the occurrence of SWC was independently associated with long-term mortality (hazard ratio, 1.81; 95% CI, 1.30-2.54; P < .001).

CONCLUSIONS

In the Arterial Revascularization Trial, postoperative SWC although uncommon were significantly associated with long-term mortality.

Comparison of Long-term Clinical Outcomes of Skeletonized vs Pedicled Internal Thoracic Artery Harvesting Techniques in the Arterial Revascularization Trial

Importance

Recent evidence has suggested that skeletonization of the internal thoracic artery (ITA) is associated with worse clinical outcomes in patients undergoing coronary artery bypass surgery (CABG).

Objective

To compare the long-term clinical outcomes of skeletonized and pedicled ITA for CABG.

Design, Setting, and Participants

The Arterial Revascularization Trial (ART) was a 2-group, multicenter trial comparing the use of a bilateral ITA vs a single ITA for CABG at 10 years. Patients in the ART trial were stratified by ITA harvesting technique: skeletonized vs pedicled. Data were collected from June 2004 to December 2017, and data were analyzed from June to July 2021.

Interventions

In this analysis, the 10-year clinical outcomes were compared between patients who received skeletonized vs pedicled ITAs.

Main Outcomes and Measures

The primary outcome was all-cause mortality. The secondary outcomes were a composite of major adverse cardiac events (MACE) including all-cause mortality, myocardial infarction, and repeated revascularization and a composite including MACE and sternal wound complication (SWC). Cox regression and propensity score matching were used.

Results

Of 2161 included patients, 295 (13.7%) were female, and the median (interquartile range) age was 65.0 (58.0-70.0) years. At 10 years, the risk of all-cause mortality was not significantly different between the pedicled and skeletonized groups (hazard ratio [HR], 1.12; 95% CI, 0.92-1.36; P = .27). However, the long-term risks of the secondary outcomes were significantly higher in the skeletonized group compared with the pedicled group (MACE: HR, 1.25; 95% CI, 1.06-1.47; P = .01; MACE and SWC: HR, 1.22; 95% CI, 1.05-1.43; P = .01). The difference was not seen when considering only patients operated on by surgeons who enrolled 51 patients or more in the trial (MACE: HR, 1.07; 95% CI, 0.82-1.39; P = .62; MACE and SWC: HR, 1.04; 95% CI, 0.80-1.34; P = .78).

Conclusions and Relevance

While the long-term survival of patients was not different between groups, the rate of adverse cardiovascular events was consistently higher in the skeletonized group and the difference was associated with surgeon-related factors. Further evidence on the outcome of skeletonized ITA is needed.

Systematic literature review evaluating evidence and mechanisms of action for platelet-rich plasma as an antibacterial agent

Platelet rich plasma or PRP is a supraphysiologic concentrate of platelets derived by centrifugation and separation of whole blood components. Along with platelets and plasma, PRP contains various cell types including white blood cells (WBC)/leukocytes, both granulocytes (neutrophils, basophils, eosinophils) and agranulocytes (monocytes, lymphocytes). Researchers and clinicians have explored the application of PRP in wound healing and prevention of surgical wound infections, such as deep sternal wounds. We conducted this systematic literature review to evaluate the preclinical and clinical evidence for the antibacterial effect of PRP and its potential mechanism of action. 526 records were identified for screening. 34 unique articles were identified to be included in this literature review for data summary. Overall, the quality of the clinical trials in this review is low, and collectively qualify as Oxford level C. Based on the available clinical data, there is a clear trend towards safety of autologous PRP and potential efficacy in deep sternal wound management. The preclinical and bench data is very compelling. The application of PRP in treatment of wounds or prevention of infection with PRP is promising but there is a need for foundational bench and preclinical animal research to optimize PRP as an antibacterial agent, and to provide data to aid in the design and conduct of well-designed RCTs with adequate power to confirm antimicrobial efficacy of PRP in specific disease states and wound types.

Multiple Grafting with Single Left Internal Mammary Artery as T-Graft with Itself

BACKGROUND

 Revascularization strategies might be limited in patients with lack of sufficient bypass graft material and increased risk of wound healing disturbances. In this regard, we present first results of patients treated with left internal mammary artery (LIMA) as T-graft with itself due to left-sided double-vessel disease, elevated risk of wound healing infection, and lack of graft material.

METHODS

 Eighteen patients were retrospectively analyzed in this study. All patients received LIMA grafting, and additional T-graft with itself during off-pump coronary artery bypass surgery. The investigation was focused on intraoperative and postoperative outcomes.

RESULTS

 LIMA-LIMA T-graft was performed in a total of 18 patients. Mean Fowler score accounted for 18.2 ± 2.9. Severe vein varicosis was present in 9 patients, and 38.9% of patients had lacking venous graft material due to prior vein stripping. A total of 2.5 ± 0.5 distal anastomoses were performed. Mean flow of LIMA-left anterior descending anastomosis was 41.72 ± 12.11 mL/min with a mean pulsatility index (PI) of 1.01 ± 0.21. Mean flow of subsequent T-graft accounted for 26.31 ± 4.22 mL/min with a mean PI of 1.59 ± 0.47. Median hospital stay was 7(6.75;8) days. No incidence of postoperative wound healing disorders was observed and all patients were discharged off hospital.

CONCLUSIONS

 LIMA as T-graft with itself to treat left-sided double-vessel disease is feasible and safe in patients with missing bypass graft material and increased risk of deep sternal wound infection. Further prospective studies are necessary to confirm our results.

Does Incisional Negative Pressure Wound Therapy Prevent Sternal Wound Infections?

BACKGROUND

 Incisional negative pressure wound therapy has been described as an effective method to prevent wound infections after open heart surgery in several publications. However, most studies have examined relatively small patient groups, only a few were randomized, and some have manufacturer-sponsorship. Most of the studies have utilized Prevena; there are only a few reports describing the PICO incisional negative pressure wound therapy system.

METHODS

 We conducted a prospective cohort study involving a propensity score-matched analysis to evaluate the effect of PICO incisional negative pressure wound therapy after coronary artery bypass grafting. A total of 180 high-risk patients with obesity or diabetes were included in the study group. The control group included 772 high-risk patients operated before the initiation of the study protocol.

RESULTS

 The rates of deep sternal wound infections in the PICO group and in the control group were 3.9 and 3.1%, respectively. The rates of superficial wound infections needing operative treatment were 3.1 and 0.8%, respectively. After propensity score matching with two groups of 174 patients, the incidence of both deep and superficial infections remained slightly elevated in the PICO group. None of the infections were due to technical difficulties or early interruption of the treatment.

CONCLUSION

 It seems that incisional negative pressure wound therapy with PICO is not effective in preventing wound infections after coronary artery bypass grafting. The main difference in this study compared with previous reports is the relatively low incidence of infections in our control group.

Decreasing complications of pectoralis major muscle flap reconstruction with two modalities of negative pressure wound therapy

BACKGROUND AND OBJECTIVE

Deep sternal wound infection is a feared complication of open-heart surgery. Negative pressure wound therapy has gained an important role in the treatment of deep sternal wound infection. Incisional negative pressure wound therapy has been introduced as a method to prevent wound complications after sternotomy, and lately, after flap reconstructions in the treatment of deep sternal wound infection. We aimed to study if incisional negative pressure wound therapy with PICO™ had similar beneficial effect described earlier with competing commercial devices.

METHODS

This study included 82 patients treated with pectoralis major muscle flap for deep sternal wound infection during the years 2006-2020. PICO group consisted of 24 patients treated with preoperative negative pressure wound therapy and postoperative incisional negative pressure wound therapy (PICO™). Two control groups included 48 patients with conventional treatment and 10 patients with preoperative negative pressure wound therapy only.

RESULTS

In the PICO group, the complication rate declined from 50.0% to 33.30%, major complication rate from 29.2% to 12.5%, and need for an additional flap from 14.6.% to 4.2% when compared to conventional treatment. The length of hospital stay decreased as well. Preoperative negative pressure wound therapy alone was associated with moderate decline in the complication rates. In addition, we described the use of split pectoralis major muscle flap reconstruction in 57 patients. To our knowledge, this is the largest published patient series describing this method in the treatment of deep sternal wound infection.

CONCLUSIONS

Incisional negative pressure wound therapy with PICO™ seems beneficial after flap reconstruction. Split pectoralis major muscle flap is a versatile reconstruction option suitable to be used as a workhorse in the treatment of deep sternal wound infection.

The Economic Implications of Introducing Single-Patient ECG Systems for Cardiac Surgery in Australia

Introduction

Sternal wound infections (SWIs) are severe adverse events of cardiac surgery. This study aimed to estimate the economic burden of SWIs following coronary artery bypass grafts (CABG) in Australia. It also aimed to estimate the national and hospital cost-benefit of adopting single-patient electrocardiograph (spECG) systems for CABG monitoring, a measure that reduces the rate of surgical site infections (SSIs).

Material and Methods

A literature review, which focused on CABG-related SSIs, was conducted to identify data which were then used to adapt a published Markov cost-effectiveness model. The model adopted an Australian hospital perspective.

Results

The average SWI-related cost of care increase per patient was estimated at 1022 Australian dollars (AUD), and the annual burden to the Australian health care system at AUD 9.2 million. SWI burden comprised 360 additional intensive care unit (ICU) days; 1979 additional general ward (GW) days; and 186 readmissions. Implementing spECG resulted in 103 fewer ICU days, 565 fewer GW days, 48 avoided readmissions, and a total national cost saving of AUD 2.5 million, annually. A hospital performing 200 yearly CABGs was estimated to save AUD 54,830.

Conclusion

SWIs cause substantial costs to the Australian health care system. Implementing new technologies shown to reduce the SWI rate is likely to benefit patients and reduce costs.

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.

Prevention of Sternal Wound Infections in Women Using an External Sternum Fixation Corset

Purpose: Deep sternal wound infection (DSWI) and mediastinitis are devastating complications after median sternotomy. Previous studies demonstrated an effective prevention of sternal wound infection (SWI) using an external sternal corset in high-risk cardiac surgery patients. The aim of this study is to assess the preventive effect of the Stern-E-Fix corset in high-risk poststernotomy female patients.

Methods: A total of 145 high-risk female patients undergoing cardiac surgery through median sternotomy were retrospectively analyzed. Patients were divided into group A (n = 71), who received the Stern-E-Fix corset (Fendel & Keuchen GmbH, Aachen, Germany), and group B (n = 74), who received the elastic thorax bandage (SanThorax) postoperatively for 6 weeks. The mean follow-up period was 12 weeks.

Results: Incidence of SWI was 7% in group A vs. 17.6% in group B (p = 0.025). One patient presented with DSWI in group A vs. seven patients in group B (p = 0.063). No patient developed mediastinitis in group A vs. four patients in group B (p = 0.121). In all, 4.2% of group A patients required operative wound therapy vs. 16.2% of group B patients (p = 0.026). The length of hospital stay was significantly longer in group B (p = 0.006).

Conclusion: Using an external supportive sternal corset (Stern-E-Fix) yields a significantly better and effective prevention against development of sternal dehiscence, DSWI, and mediastinitis in high-risk poststernotomy female patients.

Value of Perioperative Chest X-ray for the Prediction of Sternal Wound Complications after Cardiac Surgery in High-Risk Patients: A "Work in Progress" Analysis

BACKGROUND

Sternal wound complications are serious events that occur after cardiac surgery. Few studies have investigated the predictive value of chest X-ray radiological measurements for sternal complications.

METHODS

Several perioperative radiological measurements at chest X-ray and clinical characteristics were computed in 849 patients deemed at high risk for sternal dehiscence (SD) or More than Grade 1 Surgical Site Infection (MG1-SSI). Multivariable analysis identified independent predictors, whilst receiver operating characteristics (ROC) curve analyses highlighted cut-off values of radiological measurements for the prediction of both complications.

RESULTS

SD occurred in 8.8% of the patients, MG1-SSI in 6.8%. Chronic obstructive pulmonary disease (COPD) was the only independent predictor for SD (Odds Ratio, O.R. 12.1; p < 0.001); proximal sternal height (PSH) was the only independent protective factor (O.R. 0.58; p < 0.001), with a cut-off value of 11.7 mm (sensitivity 70.5%, specificity 71.0%; ROC area under the curve (AUC) = 0.768, p < 0.001). Diabetes mellitus (O.R. 3.5; p < 0.001) and COPD (O.R. 21.3; p < 0.001) were independent predictors for MG1-SSI; indexed proximal sternal height (iPSH) was as a protective factor (O.R. 0.26; p < 0.001) with a cut-off of 5.97 mm (sensitivity 70.2%, specificity 69.0%; ROC AUC = 0.739, p < 0.001). No other radiological measurements were independently correlated with SD or MG1-SS (p = N.S.).

CONCLUSION

PSH and iPSH at preoperative chest X-ray may act as indicators of high risk for sternal wound complications, allowing for early preventative measures.

The impact of incisional negative pressure wound therapy on the wound healing process after midline sternotomy

Previous studies have reported that the use of incisional negative pressure wound therapy (INPWT) might reduce the incidence of wound infections, although its mechanism remains unknown. We designed a prospective study to explore the effects of INPWT on different stages of the wound healing process. After meeting the inclusion criteria, 108 patients were enrolled. Based on exclusion criteria four patients were excluded and 104 patients were randomised into two groups. INPWT was applied after primary closure of the midline sternotomy in the study group (n = 52), while conventional wound dressing was applied in the control group (n = 52). We documented the incidence of deep sternal wound infections and analysed the pre‐ and postoperative inflammatory biomarkers and scar size in both groups. No wound infections were observed in the study group compared with six cases (11.1%) in the control group, (P = .026). No significant differences were observed in the inflammatory biomarkers between the groups. Scar size was significantly smaller in the study group. We concluded that INPWT has less effect on the inflammatory phase and appears to have more effect on the proliferation phase through pronounced scar formation.

One-year mortality increases four-fold in frail patients undergoing cardiac surgery

OBJECTIVES

METHODS

A total of 604 patients aged ≥65 years undergoing non-acute cardiac surgery were included in this single-centre prospective observational study. We compared 1-year mortality and morbidity in frail versus non-frail patients. The Comprehensive Assessment of Frailty (CAF) score was used: This is a score of 1–35 determined via minor physical tests. A CAF score ≥11 indicates frailty.

RESULTS

The median age was 73 years and 79% were men. Twenty-five percent were deemed frail. Frail patients had four-fold, odds ratios 4.63, 95% confidence interval (CI) 2.21–9.69; P &lt; 0.001 increased 1-year mortality and increased risk of postoperative complications, i.e. surgical wound infections and prolonged hospital length of stay. A univariable Cox proportional hazards regression showed that an increased CAF score was a risk factor of mortality at any time after undergoing cardiac surgery (hazards ratios 1.11, 95% CI 1.07–1.14; P &lt; 0.001).

CONCLUSIONS

CAF score identified frail patients undergoing cardiac surgery and was a good predictor of 1-year mortality.

Clinical trial registration number

NCT02992587.

The Impact of Preoperative Frailty on the Clinical and Cost Outcomes of Adult Cardiac Surgery in Alberta, Canada: A Cohort Study

Background

There is limited information about the impact of frailty on public payer costs in cardiac surgery. This study aimed to determine quality-adjusted life-years (QALYs) and costs associated with preoperative frailty in patients referred for cardiac surgery.

Methods

We retrospectively compared costs of frailty in a cohort of 529 patients aged ≥ 50 years who were referred for nonemergent cardiac surgery in Alberta. Patients were screened preoperatively for frailty, defined as a score of 5 or greater on the Clinical Frailty Scale. The primary outcome measure was public payer costs attributable to frailty, calculated in a difference-in-difference (DID) model.

Results

The prevalence of frailty was 10% (n = 51; 95% confidence interval [CI], 7%-12%). Median (interquartile range) costs for frail patients were higher in the first year postsurgery ($200,709 [$146,177-$486,852] vs $147,730 [$100,674-$177,025]; P < 0.001) compared to nonfrail; the difference-in-difference attributable cost of frailty was $57,836 (95% CI, $–28,608-$144,280). At 1 year, frail patients had fewer QALYs realized compared to nonfrail patients (0.71 [0.57-0.77] vs 0.82 [0.75-0.86], P < 0.001), whereas QALYs gained were similar (0.02 [–0.02-0.05] vs 0.02 [0.00–0.04], P = 0.58, median difference 0.003 [95% CI, –0.01-0.02]) in frail and nonfrail patients.

Conclusions

Frailty screening identified a population with greater impairment in quality-of-life and greater healthcare costs. Costs attributable to frailty represent opportunity costs that should be considered in future cardiac surgical services planning in the context of our aging population and the growing prevalence of frailty.

Effect of Skeletonization of Bilateral Internal Thoracic Arteries on Deep Sternal Wound Infections

BACKGROUND

Bilateral internal thoracic arteries (BITA) coronary bypass grafting may improve long-term outcomes but is associated with increased deep sternal wound infections (DSWIs). We analyzed whether BITA skeletonization impacts DSWIs and operative mortality (OM) using The Society of Thoracic Surgeons Adult Cardiac Surgery Database.

METHODS

Primary, isolated, nonemergent/nonsalvage BITA patients (July 2017 to December 2018) in The Society of Thoracic Surgeons Adult Cardiac Surgery Database were divided into groups based on BITA harvesting technique: both skeletonized (ssBITA) and ≥1 nonskeletonized (Non-ssBITA). DSWI and OM observed-to-expected (O/E) ratios were compared using The Society of Thoracic Surgeons Perioperative Risk Models. ssBITA versus Non-ssBITA DSWI and OM adjusted odds ratios were calculated by multivariable logistic regression and corroborated by propensity score matching.

RESULTS

We analyzed 11,269 patients (42.8% ssBITA, 57.2% Non-ssBITA, 770 hospitals, 1448 surgeons). The ssBITA group had a higher incidence of comorbidities and off-pump surgery. Overall incidences of DSWIs and OM were 0.98% (O/E ratio, 5.1) and 1.72% (O/E ratio, 1.4), respectively, and were 28% (P = .129) and 23% (P = .096) lower in ssBITA. The DSWI O/E ratio was highest (5.9) in Non-ssBITA and lowest in ss-BITA (4.1). After multivariable adjustment, ssBITA was associated with a decreased risk of DSWIs (adjusted odds ratio, 0.66; 95% confidence interval, 0.44-1.00; P = .05), with no difference in OM. These results were confirmed among 3884 propensity score-matched pairs. DSWIs increased sharply with increasing number of risk factors for DSWIs regardless of harvesting technique, with a trend for higher DSWIs among Non-ssBITA for all risk categories.

CONCLUSIONS

The observed high O/E ratio indicates that BITA grafting is associated with increased risk of DSWIs. Risk-adjusted DSWI rate and a lower O/E ratio in ssBITA support the protective role of skeletonization.

Procedure- and Hospital-Level Variation of Deep Sternal Wound Infection From All-Japan Registry

BACKGROUND

The outcome of cardiovascular surgery has been improving over time, but the treatment of postoperative complications such as deep sternal wound infection (DSWI) still needs critical attention. A nationwide surgical registry was analyzed for procedural details and hospital factors related to DSWI.

METHODS

The study used the Japan Adult Cardiovascular Surgery Database, which captured data from 82% of all the hospitals performing cardiac surgery in Japan. A total of 109,717 surgical cases (34,980 coronary artery bypass grafting, 43,602 valve operations, 31,135 thoracic aortic operations) were included in the study.

RESULTS

The overall incidence of DSWI was 1738 (1.6%). The 30-day mortality and operative mortality were 3311 (3.0%) and 5155 (4.7%), respectively. Across the 3 procedures, thoracic aortic operation showed the highest odds ratio (2.61; 95% confidence interval [CI], 2.32 to 2.94) for operative mortality but the lowest (0.91; 95% CI:,0.73 to 1.13) for DSWI incidence. Conversely, coronary artery bypass grafting showed the lowest odds ratio (1.36; 95% CI, 1.24 to 1.49) for operative mortality but the highest (1.52; 95% CI, 1.32 to 1.76) for DSWI. There was also hospital-level variation: Correlation was statistically significant between the observed-to-expected ratio of DSWI incidence and the observed-to-expected mortality ratio of cardiovascular procedures across the hospitals, but the coefficient was small (r = .24, P < .001).

CONCLUSIONS

Hospitals that have a lower risk-adjusted mortality rate of cardiovascular procedures do not always have a lower risk-adjusted DSWI occurrence rate. In addition, the incidence of DSWI varies across hospitals. We need to consider DSWI independently of surgical mortality, whereas for treatment we should consider both the specific hospital environment and the multidisciplinary care.

The Cost Effectiveness of Single-Patient-Use Electrocardiograph Cable and Lead Systems in Monitoring for Coronary Artery Bypass Graft Surgery

Background: During admission for coronary artery bypass graft (CABG) surgery patients receive electrocardiograph (ECG) monitoring; for which reusable ECG cable and leads (rECG) are standard. Objective: Evaluate the cost effectiveness of a single-patient-use ECG cable and lead system (spECG). Methods: Review of the Medicare 2011-2014 database followed by a cost-effectiveness model considering a Medicare facility transitioning from rECG ($9 per patient) to spECG ($15). In-hospital ECG monitoring was for ≤8 days. In the model, patients underwent CABG and recovered in the intensive care unit, before transfer to the general ward and discharge. Surgical site infection (SSI) resulted in increased length of stay, readmission, or outpatient care. Health outcomes impacted EQ-5D-measured quality adjusted life years (QALYs). Health and cost outcomes were discounted at 3.5% annually. All costs in 2016 USD. Significance (95% level) was assessed via 2,000 simulations. Results: In 2014, 5.49% of patients had an SSI by 90-days post-surgery, with spECG reducing the odds of an SSI (odds ratio: 0.74, 0.62-0.89). Mean 40-year, per-patient costs to Medicare were $65,497 with rECG and $65,048 with spECG. The $450 saving was significant, with a median (95% credible interval) reduction of $466 ($174 to $989). Cost drivers were days required to treat inpatient SSIs. QALYs increases with spECG were significant but minor (median increase 0.008). Medicare savings may total $40 million per year with use of spECG. Conclusions: Post-operative SSI is a concern for Medicare patients undergoing CABG, and use of spECG is likely to provide cost and patient benefits.

Cost-Effectiveness of Negative Pressure Incision Management System in Cardiac Surgery

BACKGROUND

Sternal wound infections (SWIs) can be a devastating long-term complication with significant morbidity and health care cost. The purpose of this analysis was to evaluate the cost-effectiveness of negative pressure incision management systems (NPIMS) in cardiac surgery.

MATERIALS AND METHODS

All cardiac surgery cases at an academic hospital with risk scores available (2009-2017) were extracted from an institutional database (n = 4455). Patients were stratified by utilization of NPIMS, and high risk was defined as above the median. Costs included infection-related readmissions and were adjusted for inflation. Multivariable regression models assessed the risk-adjusted cost of SWI and efficacy of NPIMS use. Cost-effectiveness was modeled using TreeAge Pro using institutional results.

RESULTS

The rate of deep SWI was 0.9% with an estimated cost of $111,175 (P < 0.0001). The rate of superficial SWI was 0.8% at a cost of $7981 (P = 0.08). Risk-adjusted NPIMS use was not significantly associated with reduced SWI (OR 1.2, P = 0.62) and thus not cost-effective. However, in the high-risk cohort with an OR 0.84 (P = 0.72) and SWI rate of 2.3%, NPIMS use cost $205 per patient with an incremental cost-effectiveness ratio of $179,092. Therefore, NPIMS is estimated to be cost-effective with a deep SWI rate over 1.3% or improved efficacy (OR < 0.83).

CONCLUSIONS

SWIs are extremely expensive complications with estimates of $111,175 for deep yet only $7981 for superficial. Although NPIMS was not cost-effective for SWI prevention as currently utilized, a protocol for use on patients with a higher risk of sternal infection could be cost-effective.

Toxicity and Safety Study of D-PLEX100 in a Sternal Surgical Defect in New Zealand White Rabbits

Bacterial infections are a common complication after surgical procedures. Therefore, local delivery of antibiotics has been developed, including the use of biodegradable polymers. A newly developed product for prevention of surgical site infections is a polymer-lipid encapsulation matrix loaded with doxycycline, named D-PLEX₁₀₀ (D-PLEX). We evaluated the toxicity and safety of D-PLEX using a sternal surgical defect model in rabbits. D-PLEX was tested with three different concentrations of doxycycline in comparison to sham-operated control after administration into the sternal surgical defect and on the ventral side of the sternum in New Zealand White (NZW) rabbits, following 15 months of exposure. No mortality or abnormal clinical findings were attributed to D-PLEX, and clinical pathology assays were normal. Histological examinations revealed no treatment-related adverse findings in any of the examined tissues, including the osseous and surrounding soft tissues. It has been shown that D-PLEX gradually degraded until complete disappearance after 9 months, and mainly during the first 3 months, in parallel to normal bone formation. In addition, the administration of D-PLEX did not affect sternal bone strength. This study adds to the growing data on preclinical safety studies utilizing biodegradable materials and provides information on the expected normal reaction to biodegradable materials in the sternum of NZW rabbits.

Implementation of an evidence-based practice to decrease surgical site infection after coronary artery bypass grafting

Objective

Surgical site infection (SSI) is a serious complication after coronary artery bypass grafting (CABG). This study was performed to evaluate evidence-based practice and structured problem-solving to reduce SSI after CABG.

Methods

An infection control strategy including supervised chlorhexidine gluconate (CHG) showers was implemented from January 2017 to March 2018 for 119 patients undergoing CABG. The controls comprised 244 patients who underwent CABG from 2014 to 2016. Risk factors for SSI were identified, and a problem-focused strategy was used to control SSI. Propensity score matching was used to study the effect of CHG showers on SSI.

Results

SSI occurred in 25 patients (10.25%) in the control group, and the significant risk factors were the postoperative blood glucose level, transfer from an outside hospital, emergency operation, redo sternotomy, a higher American Society of Anesthesiologists score, and the duration of surgery. After implementation of the program, the SSI rate significantly decreased to 3.36%. Patients who had undergone preoperative CHG showers had a significantly lower SSI rate (1.69%) than the matched controls (13.56%).

Conclusion

SSI after CABG can be reduced using evidence-based practice and structured problem-solving to identify risk factors. A preoperative CHG shower is associated with a lower SSI rate after CABG.

Standardized Musculocutaneous Flap for the Coverage of Deep Sternal Wounds After Cardiac Surgery

BACKGROUND

Deep sternal wound infection remains a serious complication after cardiac surgery, leading to increased morbidity, mortality, and cost. The goal of our study was to develop a standardized, reproducible method to safely cover deep sternal wounds and ensure improved healing rates.

METHODS

The study was developed as a retrospective cohort study. We included 58 patients who received standardized latissimus dorsi flap coverage of a sternum defect wound after poststernotomy mediastinitis at our institution between September 2015 and June 2017.

RESULTS

The average age of the cohort was 66.75 years, and 51.72% of patients were men. The mean hospital stay was 26.83 days. Eight patients (14.75%) died during the hospital stay due to sepsis or heart failure. The average flap size was 137.13 cm². The mean operative time was 155 minutes. Seventy-four percent of patients developed a seroma at the donor site, which was treated conservatively with compression garments and taps, and 7% of patients developed a wound dehiscence of the donor site, which was treated conservatively with dressings. The mean follow-up time was 15 weeks. All 50 surviving patients showed complete wound healing on follow-up.

CONCLUSIONS

The latissimus dorsi pedicled flap is a safe, reproducible technique for coverage of deep sternal wounds, with few relevant perioperative complications. By setting definite parameters for the flap dissection and by ensuring a reliable blood supply, our method enables the coverage of these complex wounds by an interdisciplinary team in any cardiovascular surgical setting.

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.

Current perspectives on diagnosis and management of sternal wound infections

Deep sternal wound infection (DSWI), also known as mediastinitis, is a serious and potentially fatal condition. The diagnosis and treatment of DSWI are challenging. In this current narrative review, the epidemiology, risk factors, diagnosis, and surgical and antimicrobial management of DSWI are discussed. Ideally, the management of DSWI requires early and sufficient surgical debridement and appropriate antibiotic therapy. When foreign material is present, biofilm-active antibiotic therapy is also needed. Because DSWI is often complex, the management requires the involvement of a multidisciplinary team consisting of cardiothoracic surgeons, plastic surgeons, intensivists, infectious disease specialists, and clinical microbiologists.

Hyperglycemic Episodes Are Associated With Postoperative Infections After Cardiac Surgery

BACKGROUND AND AIMS

To describe the incidence of and risk factors for postoperative infections and the correlation between postoperative hyperglycemia despite tight blood glucose control with infectious and other complications after contemporary cardiac surgery.

MATERIAL AND METHODS

The study comprised 1356 consecutive adult patients who underwent cardiac surgery between January 2013 and December 2014 and were followed up for 6 months. Patients surviving the first 2 days were included in the analysis. Preoperative demographic information, medical history, procedural details, and the postoperative course were recorded. The target range for blood glucose levels was 4-7 mmol/L and repeated arterial blood samples were obtained during the intensive care unit stay. The associations of blood glucose levels during the first postoperative day and the occurrence of postoperative infections and other significant complications were analyzed.

RESULTS

Of the study cohort, 9.8% developed infectious complications which were classified as major surgical site infections in 2.2%, minor surgical site infections in 1.1%, lung infections in 2.0%, unclear fever or bacteremia in 0.3%, cannula or catheter related in 2.6%, multiple in 1.5%, and other in 0.2%. The incidence of deep sternal wound infection was 2.0%. Repeated hyperglycemia occurred in 39.7% of patients and was associated with increased rates of postoperative infections, 12.1% versus 8.2%, p = 0.019; stroke, 4.9% versus 1.5%, p < 0.001; and mortality, 6.1% versus 2.1%, p < 0.001, when compared to patients with single or no hyperglycemia.

CONCLUSION

Every 10th patient develops infectious complications after cardiac surgery. Repeated hyperglycemia is associated with increased rates of infectious complications, stroke, and mortality.