Risk factors and management approach for deep sternal wound infection after cardiac surgery at a tertiary medical centre

Effectiveness of rigid plate fixation for sternal closure in patients with a high risk of deep sternal wound infection

OBJECTIVE

Median sternotomy is a standard approach in cardiovascular surgery, and wire fixation is commonly used for sternal closure. However, postoperative intermittent stress on the sternum can lead to sternal breakdown, potentially resulting in deep sternal wound infection (DSWI). Sternal closure with rigid plate fixation was recently reported to be effective for preventing DSWI and promoting sternal healing. We investigated the effectiveness of a rigid plate fixation system in patients at a high risk of developing DSWI.

METHODS

This retrospective observational study evaluated the incidence of DSWI and the progression of postoperative sternal fusion observed on computed tomography. Forty-eight patients at a high risk of DSWI who underwent sternal closure with a rigid plate fixation system between 2020 and 2023 were assessed.

RESULTS

Among the 48 patients, 1 (2.1%) developed DSWI requiring surgical treatment. Sternal fusion improved over time, with significant progression observed during the follow-up period compared with the early postoperative period. Additionally, patients who did not show sternal fusion in the early postoperative period showed progressive fusion during follow-up.

CONCLUSIONS

The rigid plate fixation system prevents sternal displacement and may be beneficial in preventing DSWI by maintaining and promoting sternal fusion in high-risk patients.

Post-operative infections after cardiothoracic surgery and vascular procedures: a bibliometric and visual analysis of the 100 most-cited articles in the past 2 decades

Aim

To recognize and analyze the 100 most-cited articles on post-operative infections following cardiothoracic surgery and vascular procedures in the past 20 years.

Methods

Articles published on post-operative infections following cardiothoracic surgery and vascular procedures from inception 1986 till 2020 were reviewed and selected by two authors, based on their number of citations using the Scopus database. Their characteristics were recorded, i.e., title, authors, publication date, total no. of citations, citations per year (CPY), country of research, institutional affiliation, journal, research subject, and article type.

Results

The top 100 most influential articles were published between 1968 and 2017, with the peak in 2002. The mean number of total citations was 236.79 (range: 108-1,157). Areas with a medical focus were predominant in the studied research articles on the researched topic. The top-most journals in which these articles were published include Annals of Thoracic Surgery (14), followed by Circulation (8), and the New England Journal of Medicine (8). The number of publications affiliated with an institution were highest in the United States, with the Cleveland Clinic Foundation (6) having the most.

Conclusion

These findings highlight that there is a great potential to conduct research and publish the prevalence, causes, risk factors, pathogenesis and molecular biology of post-cardiac and -vascular surgery infections to prevent their adverse effects. The results can be taken into consideration for policy making to improve post-cardiac-surgery outcomes.

Risk factors for sternal wound infection after open-heart operations: A systematic review and meta-analysis

We aimed to quantitatively and systematically elucidate the rationality of the examined variables as independent risk factors for sternal wound infection. We searched databases to screen studies, ascertained the variables to be analysed, extracted the data and applied meta-analysis to each qualified variable. Odds ratios and mean differences were considered to be the effect sizes for binary and continuous variables, respectively. A random-effects model was used for these procedures. The source of heterogeneity was evaluated using a meta-regression. Publication bias was tested by funnel plot and Egger's test, the significant results of which were then calculated using trim and fill analysis. We used a sensitivity analysis and bubble chart to describe their robustness. After screening all variables in the eligible literature, we excluded 55 because only one or no research found them significant after multivariate analysis, leaving 33 variables for synthesis. Two binary variables (age over 65 years, NYHA class >2) and a continuous variable (preoperative stay) were not significant after the meta-analysis. The most robust independent risk factors in our study were diabetes mellitus, obesity, use of bilateral internal thoracic arteries, chronic obstructive pulmonary disease, prolonged surgery time, prolonged ventilation and critical preoperative state, followed by congestive heart failure, atrial fibrillation, renal insufficiency, stroke, peripheral vascular disease and use of an intra-aortic balloon pump. Relatively low-risk factors were emergent/urgent surgery, smoking, myocardial infarction, combined surgery and coronary artery bypass grafting. Sternal wound infection after open-heart surgery is a multifactorial disease. The detected risk factors significantly affected the wound healing process, but some were different in strength. Anything that affects wound healing and antibacterial ability, such as lack of oxygen, local haemodynamic disorders, malnutrition condition and compromised immune system will increase the risk, and this reminds us of comprehensive treatment during the perioperative period.

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.

Multidisciplinary Management of Sternal Osteomyelitis Due to Klebsiella aerogenes after Open Heart Surgery in a Patient with Multiple Myeloma: A Case Report and Discussion of the Literature

Sternal wound complications following cardiac surgery, including sternal dehiscence, mediastinitis, and osteomyelitis, pose significant challenges in terms of management and patient outcomes. We present a case report highlighting the complex management of a patient who underwent open heart surgery for severe aortic valve stenosis, followed by sternal wound dehiscence and sternum osteomyelitis due to extended spectrum beta lactamase (ESBL) producing Klebsiella aerogenes. A multiple myeloma diagnosis was also suspected at the positron emission tomography (PET) scan and confirmed with bone marrow biopsy. Multidisciplinary evaluation of the case led to a comprehensive treatment plan. To control the sternal osteomyelitis, total sternectomy was performed followed by immediate reconstruction with a bone (tibia) graft from the tissue bank and fixation with the minimal hardware possible. A microsurgical latissimus dorsi free flap was required to reconstruct the soft tissue defect. After 6 weeks of antibiotic treatment with ertapenem and fosfomycin based on a culture of intraoperative material, no clinical, imaging, or laboratory signs of infection were seen. Multiple myeloma treatment was then started. At 1 year of follow up, no recurrence of infection occurred, and the reconstruction was stable and closed. Multiple myeloma is under chronic treatment with novel agent combination, with an excellent haematological response.

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.

Large Sternoabdominal Wound Dehiscence after Cardiac Surgery: Challenging Multimodal Treatment

ABSTRACT

The authors report the case of a patient who presented with a nonhealing sternal wound 3 months after cardiac bypass surgery. The patient was treated with vacuum-assisted closure, surgical debridement, and IV antibiotics. Despite repeated flap closure procedures, a top closure device, and wound dressings, the patient developed an infection, and the wound size increased from 8 × 10 cm to 20 × 20 cm, advancing from the sternal to upper abdominal region. This wound was then treated with hyperbaric oxygen therapy and nonmedicated dressings until the patient was eligible to receive a split-thickness skin graft 1.5 years after initial presentation. The main takeaway from this case was that local and systemic factors affected the outcome of each surgical closure. The failure of each preceding treatment choice that led to further increases in size and area of the wound was the main challenge. Eliminating infection, preventing development of new infection, and managing the local and systemic factors before any definite surgery are key to the eventual wound closure.

Epidemiology and outcomes of bone and joint infections in solid organ transplant recipients

Bone and joint infection (BJI) epidemiology and outcomes in solid organ transplant recipients (SOTr) remain largely unknown. We aim to describe BJI in a multi-center cohort of SOTr (Swiss Transplant Cohort Study). All consecutive SOTr with BJI (01.05.2008-31.12.2019) were included. A nested case-control study to identify risk factors for BJI was performed. Among 4482 patients, 61 SOTr with 82 BJI were included, at an incidence of 1.4% (95% CI 1.1-1.7), higher in heart and kidney-pancreas SOTr (Gray's test p < .01). Although BJI were predominately late events (median of 18.5 months post-SOT), most infections occurred during the first year post-transplant in thoracic SOTr. Diabetic foot osteomyelitis was the most frequent infection (38/82, 46.3%), followed by non-vertebral osteomyelitis (26/82, 31.7%). Pathogens included Gram-positive cocci (70/131, 53.4%), Gram-negative bacilli (34/131, 26.0%), and fungi (9/131, 6.9%). BJI predictors included male gender (OR 2.94, 95% CI 1.26-6.89) and diabetes (OR 2.97, 95% CI 1.34-6.56). Treatment failure was observed in 25.9% (21/81) patients and 1-year mortality post-BJI diagnosis was 14.8% (9/61). BJI remain a rare event in SOTr, associated with subtle clinical presentations, high morbidity and relapses, requiring additional studies in the future.

Analysis of Risk Factors for Sternal Wound Infection After Off-Pump Coronary Artery Bypass Grafting

Objective

To investigate the risk factors of deep sternal wound infection (DSWI) after off-pump coronary artery bypass grafting and its prevention and treatment strategy.

Methods

The clinical data of 465 patients who underwent OPCABG with a median chest incision were retrospectively analyzed. The patients were divided into the observation group (with DSWI, 32 cases) and the control group (without DSWI, 433 cases) according to the occurrence of DSWI. The preoperative, intraoperative, and postoperative clinical data relevant to DSWI were collected in both groups. The univariate and multivariate logistic regression analyses were adopted to analyze the risk factors for DSWI after OPCABG and investigateand its prevention and treatment strategy.

Results

DSWI occurred in 32 cases with an incidence of infection of 6.89%. There were 5 cases died in the observation group (with DSWI), the overall mortality rate was 1.07% and the intra-group mortality rate was 15.6%. There were 16 cases died in the control group (without DSWI) because of low cardiac output syndrome and multiple organ failure, the overall and intra-group mortality rates were 3.44% and 3.69% respectively. By analyzing the risk factors of DSWI between the two groups, the differences in age, body mass index (BMI), history of diabetes mellitus (DM), operation time, tracheal intubation time, time of stay in thecardiac care unit, blood transfusion (blood plasma)>800mL, blood transfusion (erythrocyte suspension)>6um, secondary thoracotomy were statistically significant between the observation and control groups (P < 0.05 in all).

Conclusion

Obesity, history of DM, prolonged operation time and tracheal intubation time, time of stay in CCU, utilization of blood product and secondary thoracotomy were DSWI independent risk factors after OPCABG.Some preventive measure should been implemented to reduce the incidence of DSWI, such as shorter operation time and tracheal intubation time, reducing the utilization of blood product.

Topical Vancomycin Reduces the Incidence of Deep Sternal Wound Complications After Sternotomy

BACKGROUND

Deep sternal wound infection remains a significant hazard for cardiosurgical patients undergoing median sternotomy. Although the prophylactic use of topical vancomycin to reduce the incidence of deep sternal wound complications (DSWC) has been repeatedly examined, the method remains controversial.

METHODS

We report here on a continuous experience that encompassed a total of 1251 cardiosurgical patients who underwent various procedures via median sternotomy. Beginning in October 2015 and in response to a surge of DSWC (4.4%), 3 surgeons on our team began to apply 2.5 g vancomycin paste to the sternal edges just prior to closure, while the remaining 2 surgeons did not. An interim analysis comparing the 2 groups suggested that vancomycin was indeed effective, and from February 2016 on, all surgeons adopted the routine use of vancomycin in all patients.

RESULTS

Retrospective analysis of 496 surgical patients from January to September 2015 had revealed a baseline incidence of DSWC of 4.4%. In the divided-use period between October 2015 and February 2016, DSWC was seen in 8.6% (8 of 93) of the no-vancomycin group. In the vancomycin group, the incidence fell to 0.8% (1 of 129). In March 2016, all surgeons began using vancomycin and the overall rate of DSWC for all surgeons and all patients subsequently declined to 1.1%. No adverse effects were observed.

CONCLUSIONS

Topical vancomycin application is highly effective in the prevention of DSWC after median sternotomy.

Deep sternal wound infection and pectoralis major muscle flap reconstruction: A single-center 20-year retrospective study

Background

One of the most drastic complications of median sternal incision is deep sternal wound infection (DSWI), as it can lead to prolonged hospitalization, increased expected costs, re-entry into the ICU and even reoperation. Since the pectoralis major muscle flap (PMMF) technique was proposed in the 1980s, it has been widely used for sternal reconstruction after debridement. Although numerous studies on DSWI have been conducted over the years, the literature on DSWI in Chinese population remains limited. The purpose of this study was to investigate the clinical characteristics of DSWI in patients and the clinical effect of the PMMF at our institution.

Methods

This study retrospectively analyzed all 14,250 consecutive patients who underwent cardiac surgery in the Department of Cardiothoracic Surgery of Drum Tower Hospital from 2001 to 2020. Ultimately, 134 patients were diagnosed with DSWI.,31 of whom had recently undergone radical debridement and transposition of the PMMF in the cardiothoracic surgery or burns and plastic surgery departments because of DSWIs, while the remaining patients had undergone conservative treatment or other methods of dressing debridement.

Results

In total, 9,824 patients were enrolled in the study between 2001 and 2020, of whom 134 met the DSWI criteria and 9690 served as controls. Body mass index (OR = 1.08; P = 0.02; 95% CI, 1.01∼1.16) and repeat sternotomy (OR = 5.93; P &lt; 0.01; 95% CI, 2.88∼12.25) were important risk factors for DSWI. Of the 134 patients with DSWI, 31 underwent the PMMF technique, and the remaining 103 served as controls. There were significant differences in coronary artery bypass grafting (CABG) (P &lt; 0.01), valve replacement (P = 0.04) and repeat sternotomy (P &lt; 0.01) between the case group and the control group. The postoperative extubation time (P &lt; 0.001), ICU time (P &lt; 0.001), total hospitalization time (P &lt; 0.001) and postoperative hospitalization time (P &lt; 0.001) in the PMMF group were significantly lower than those in the control group. The results of multivariate regression analysis showed that PMMF surgery was an important protective factor for the postoperative survival of DSWI patients (OR = 0.12; P = 0.04; 95% CI, 0.01∼0.90).

Conclusions

Staphylococcus aureus was the most common bacteria causing DSWI, which was associated with BMI and reoperation, and can be validly treated with PMMF.

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.

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.

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.

The association between preoperative length of hospital stay and deep sternal wound infection: A scoping review

BACKGROUND

Deep sternal wound infection (DSWI) is a serious complication of cardiac surgery, associated with a significantly longer hospital stay, an increased mortality, and an almost doubling of treatment costs. The preoperative length of hospital stay has been suggested in a small number of studies as a modifiable risk factor yet is not included in surgical site infection prevention guidelines. The aim of this scoping review was to review the existing evidence on the association between preoperative length of hospital stay and DSWI, and to identify established risk factors for DSWI.

METHODS

A literature search of six electronic databases yielded 2297 results. Titles concerning risk factors for DSWI, sternal or surgical wound infection, or poststernotomy complications were included. Abstracts relating to preoperative length of stay as a risk factor for DSWI proceeded to full article review. Articles regarding paediatric surgery, DSWI management or unavailable in English were excluded.

RESULTS

The review identified 11 observational cohort studies. DSWI prevalence was between 0.9% and 6.8%. Preoperative length of stay ranged from 0-15.5 days and was found to be associated with DSWI in all studies. Preoperative length of stay and DSWI were inconsistently defined. Other risk factors for DSWI included diabetes, obesity, respiratory disease, heart failure, renal impairment, complex surgery, and reoperation (p < 0.05).

CONCLUSION

In this scoping review, an association between preoperative length of stay and the development of DSWI following cardiac surgery was identified. Thus, preoperative length of stay as a modifiable risk factor for DSWI should be considered for inclusion in cardiothoracic surgical infection prevention guidelines.

Incidence, types and outcomes of sternal wound infections after cardiac surgery in Saudi Arabia. A retrospective medical chart review

Objectives:

To determine the incidence, types, risk factors, identify organisms, and assess outcomes of surgical wound infections (SWIs) after cardiac surgery at a tertiary hospital in Riyadh, Saudi Arabia.

Methods:

This historical cohort study reviewed the chart of patients who underwent cardiac surgery at King Khalid University Hospital, Riyadh, Saudi Arabia between January 2009 and December 2014. The proforma contained personal data, comorbidities, type of surgery, microbiological analysis, and management outcomes.

Results:

A total of 1241 patients were enrolled in the study comprising 1,032 (83.2%) men and 209 (16.8%) women. Forty (3.2%) patients developed SWI, of which 32 (2.5%) were superficial and 8 (0.7%) were deep. Gender, obesity, diabetes mellitus, non-use of statins, and coronary artery bypass graft (CABG) surgery were not significant predictors of infection in the study. Methicillin-susceptible Staphylococcus aureus was isolated predominantly in 45%, followed by Klebsiella and Pseudomonas species. Methicillin-resistant Staphylococcus aureus, Enterococcus faecium, and extended β-lactamase-producing gram-negative organisms were pathogens isolated in last 3 years of the review. Simple and vacuum assisted closure therapies led to complete resolution in 32 (80%) patients, while 8 (20%) developed sternal osteomyelitis. All patients survived except one with a deep SWI who died of uncontrolled sepsis.

Conclusion:

Despite the low incidence of postoperative SWIs, the risk of sternal osteomyelitis development persists. Meticulous choice of CABG components and appropriate postoperative management, especially detecting early signs of SWI could contribute to lower its incidence and complications.

Bilateral-pectoral major muscle advancement flap combined with vacuum-assisted closure therapy for the treatment of deep sternal wound infections after cardiac surgery

Objectives

The median sternotomy is the most common surgical approach for cardiac surgery. Deep sternal wound infection is a fatal complication after median sternotomy. The aim of this study was to evaluate the therapeutic effect of Bilateral-pectoral major muscle advancement flap combined with Vacuum-assisted closure therapy on rehabilitation for the treatment of deep sternal wound infection after cardiac surgery.

Methods

Between January 2016 to January 2018, 21 patients (10 males, 11 females) with deep sternal wound infection after cardiac surgery underwent Bilateral-pectoral major muscle advancement flap combined with Vacuum-assisted closure therapy. These patients were followed-up 12 months postoperative. The patient characteristics, duration of vacuum-assisted closure therapy, the mean hospital stay, postoperative complications, long-term survival of patients were retrospectively analyzed.

Results

Most patients undergone 1–3 times vacuum-assisted closure treatment sessions before closure. All patients were cured to discharge, the mean hospital stay was 21.1 days. Most patients’ healing wounds were first-stage healing, only one patient’s wound was second-stage healing, none was third-stage healing. One patient developed pulmonary infection and respiratory failure during the 12-month follow-up. None of the patients died during follow-up.

Conclusions

Bilateral-pectoral major muscle advancement flap combined with Vacuum-assisted closure therapy for the treatment of deep sternal wound infections after cardiac surgery can shorten the hospital stays and few complications. However, this is a retrospective case series presentation with no comparison group, the number of inferences is limited, so further large-scale controlled studies are needed.

Effective Combination of Different Surgical Strategies for Deep Sternal Wound Infection and Mediastinitis

Purpose: Timing and ideal reconstructive approach in deep sternal wound infection (DSWI) and mediastinitis still remain controversially debated. We present our own combined surgical strategy of bilateral pectoralis major muscle flap (BPMMF) or omental flap (OF) transposition.

Methods: Between July 2010 and July 2016, poststernotomy patients with DSWI and mediastinitis underwent a secondary wound closure with modified BPMMF (Group A, center for disease control class (CDC)-II, n = 21; Group B, CDC-III, n = 20) or with OF (Group C, CDC-III, n = 19) following vacuum-assisted closure (VAC).

Results: Significant risk factors for mediastinitis (CDC-III) were chronic obstructive pulmonary disease (COPD; p = 0.001), peripheral arterial disease (PAD; p = 0.012), cardiopulmonary bypass (CPB) time (p = 0.027), total operation time (p = 0.039), total intensive care unit (ICU) stay (p = 0.011), and blood transfusion (p = 0.049). Mean antibiotic therapy (18.4 ± 8.8[B] vs. 36.2 ± 24.4[C] days, p = 0.026) and length of hospitalization (25.2 ± 12.1[B] vs 53.8 ± 18.5 days[C], p = 0.053) were significantly longer in group C. In-hospital death was 3/19 (15.8%) in group C versus 0 in group B (p = 0.026). Frequency of recurrent mediastinitis was equal (p = 0.92); however, complications occurred more often in group C (31.6% vs. 0%, p = 0.031). The mean follow-up time was 111 ± 62 days.

Conclusion: In younger (<70 years) patients without sternal bone necrosis, the BPMMF is superior to the OF technique with relatively low recurrence and mortality risks.

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.

Deep sternal wound infection after cardiac surgery: a comparison of three different wound infection types and an analysis of antibiotic resistance

Background

Deep sternal wound infection (DSWI) is a severe complication following cardiac surgery. We compared epidemiology, clinical features, and microbiology of three types of DSWI and examined the antibiotic resistance in DSWI patients.

Methods

From 2011 to 2015, 170 adult post-cardiac surgery DSWI patients were recruited for this study and underwent the pectoralis major muscle flap transposition in our department.

Results

Of 170 adult patients with DSWI (mean age of 54 years), the majority (99 patients, 58.2%) had type II DSWI. The three types of DSWI patients showed significant differences in terms of gender, smoking history, chronic obstructive pulmonary disease (COPD), length of intensive care unit (ICU) stay, and hospitalization cost (P<0.05). The most common symptoms of DSWI patients were fever and wound dehiscence accompanied by purulent secretions. Types I and II DSWI were more frequently associated with hypoproteinemia and high leucocyte count (P<0.05). Microbiological diagnosis was available for 77 of 170 patients (45.3%). Of 157 pathogens detected, 87 (55.4%) species of gram negative bacilli were identified and most commonly were Pseudomonas aeruginosa (25.5%) and methicillin-susceptible Staphylococcus aureus (20.4%). However, no statistically significant microbiological differences among the three DSWI types were observed (P>0.05). Notably, P. aeruginosa isolates showed 100% resistance to cefazolin and cefuroxime. Meanwhile, the resistance rate of Acinetobacter baumannii isolates to commonly used antibiotics was greater than 70%, while resistance rates of staphylococcus to penicillin-G were 100% and to clindamycin were over 70%. No isolates were resistant to vancomycin, linezolid, and tigecycline.

Conclusions

Three types of DSWI exhibit differences in epidemiology and clinical features. P. aeruginosa and S. aureus are the most common pathogens in DSWI patients and antibiotic resistance is a serious concern in these patients. Therefore, prevention and treatment of DSWI should be closely tailored to clinical features, local microbiological characteristics, and resistance patterns of commonly encountered pathogens.

A National Study of the Impact of Delayed Flap Timing for Treatment of Patients with Deep Sternal Wound Infection

BACKGROUND

This study aimed to evaluate the impact of delayed flap closure on mortality and resource use for treatment of deep sternal wound infection.

METHODS

The authors analyzed the Truven MarketScan Databases from 2009 to 2013 to identify adult patients who developed deep sternal wound infection after open cardiac surgery and who underwent flap closure for treatment. A multivariable logistic regression model was created to evaluate the relationship between mortality and flap timing. Multivariable Poisson regressions were used to investigate the relationship between flap timing and number of procedures, number of hospitalizations, and length of stay outcomes. A multivariable log-linear regression model was created for cost analysis. All analyses were adjusted for patient risk factors and treatment characteristics.

RESULTS

The authors identified 612 patients with deep sternal wound infection who underwent flap closure. The timing of flap closure was delayed more than 7 days after diagnosis in 39 percent of patients. Delayed time to flap closure greater than 3 days after diagnosis of infection was associated with higher mortality odds for delay 4 to 7 days (OR, 2.94) and delay greater than 7 days (OR, 2.75; p < 0.03), greater additional procedures for delay 4 to 7 days (incidence rate ratio, 1.72) and delay greater than 7 days (incidence rate ratio, 1.93; p < 0.001), and up to 43 percent longer hospital length of stay and 37 percent greater costs compared with patients undergoing flap closure 0 to 3 days after diagnosis.

CONCLUSIONS

Delay in flap closure was associated with greater mortality and resource use. Prompt involvement of reconstructive surgeons may improve quality and efficiency of deep sternal wound infection care.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Deep sternal wound infection after cardiac surgery in the Chinese population: a single-centre 15-year retrospective study

Background

Deep sternal wound infection (DSWI) is a severe complication following cardiac surgery. A retrospective study was implemented to determine the risks and clinical characteristics of DSWI after cardiac operation in the Chinese population.

Methods

We analysed 7,944 consecutive patients who underwent cardiac surgery via median sternotomy from January 2002 to December 2016 at our institution. Multiple logistic regression analysis was used to identify risk factors for DSWI.

Results

A total of 106 patients (1.33%) suffered from DSWI; significant risk factors included body mass index (BMI) (P=0.02; OR=1.08; 95% CI: 1.01-1.16) and reoperation (P<0.01; OR=5.93; 95% CI: 2.88-12.25). The most common bacterium involved in DSWI was staphylococcus aureus (23%). Among all DSWI patients, the overall survival rate of the group treated with flap reconstruction was significantly higher than that in the group treated with intravenous antibiotics and sternal debridement (87% vs. 59%, P=0.01).

Conclusions

DSWI was associated with several risk factors. Effective intervention strategies could improve the outcome of patients undergoing cardiac surgery.

Therapy options in deep sternal wound infection: Sternal plating versus muscle flap

Background

Management of deep sternal wound infection (DSWI) in cardiac surgical patients still remains challenging. A variety of treatment strategies has been described. Aim of this cohort study was to analyse two different treatment strategies for DSWI: titanium sternal plating system (TSFS) and muscle flap coverage (MFC).

Methods

Between January 2007 and December 2011, from 3122 patients undergoing cardiac surgery 42 were identified with DSWI and treated with one of the above mentioned strategies. In-hospital data were collected, follow-up performed by telephone and assessment of Quality of Life (QoL) using the SF-12 Health Survey Questionnaire.

Results

20 patients with deep sternal wound infection were stabilized with TSFS and 22 patients treated with MFC. Preoperative demographics and risk factors did not reveal any significant differences. Patients treated with TSFS had a significantly shorter operation time (p<0.05) and shorter hospitalization (p<0.05). A tendency towards lower mortality rate (p = n.s.) and less re-interventions were also noted (plating 0.6 vs. flap 1.17 per patient, n.s.). Quality of Life in the TSFS group for the physical-summary-score was significantly elevated compared to the MFC group (p<0.05). Relating to chest stability and cosmetic result the treatment with TSFS showed superior results, but the usage of MFC gave the patients more freedom in breathing and less chest pain.

Conclusion

Our results demonstrate that the use of TSFS is a feasible and safe alternative in DSWI. However, MFC remains an absolutely essential option for complicated DSWI since the amount of perfused tissue can be the key for infection control.

The impact of surgical site occurrences and the role of closed incision negative pressure therapy

Surgical site occurrences are observed in up to 60% of inpatient surgical procedures in industrialised countries. The most relevant postoperative complication is surgical site infection (SSI) because of its impact on patient outcomes and enormous treatment costs. Literature reviews ('SSI', 'deep sternal wound infections' (DSWI), 'closed incision negative pressure wound therapy' (ciNPT) were performed by electronically searching MEDLINE (PubMed) and subsequently using a 'snowball' method of continued searches of the references in the identified publications. Search criteria included publications in all languages, various study types and publication in a peer-reviewed journal. The SSI literature search identified 1325, the DSWI search 590 and the ciNPT search 103 publications that fulfilled the search criteria. Patient-related SSI risk factors (diabetes mellitus, obesity, smoking, hypertension, female gender) and operation-related SSI risk factors (re-exploration, emergency operations, prolonged ventilation, prolonged operation duration) exist. We found that patient- and operation-related SSI risk factors were often different for each speciality and/or operative procedure. Based on the evidence, we found that high-risk incisions (sternotomy and incisions in extremities after high-energy open trauma) are principally recommended for ciNPT use. In 'lower'-risk incisions, the addition of patient-related or operation-related risk factors justifies the application of ciNPT.

Delayed aortic rupture resulting from postoperative superficial sternal wound infection

While deep sternal wound infection (DSWI) after cardiac surgery is a significant contributor to patient morbidity and mortality, superficial sternal wound infection (SSWI) mostly has a benign course. We report a mortality case of aortic rupture resulting from SSWI after cardiac surgery. A 50-year-old male underwent an aortic valve replacement (AVR). Three months after the valve operation, he presented with severe dyspnea, which had never before been observed, and chest computed tomography revealed an ascending aortic rupture with large hematoma compressing the main pulmonary artery. We performed an emergent operation for aortic rupture that possibly originated from the SSWI. Postoperatively, the patient died of hypovolemic shock due to recurrent aortic rupture despite efforts to resuscitate him.

Can Drainage Using a Negative-Pressure Wound Therapy Device Replace Traditional Sample Collection Methods?

BACKGROUND

In 2015 a new device for the collection of mediastinal fluid from patients with deep sternal wound infection (DSWI) in the presence of negative-pressure wound therapy (NPWT) became available. The present study was designed to evaluate whether changing sample collection devices increased micro-organism detection in patients undergoing NPWT.

METHODS

During 2013-2014, 207 samples were collected and cultured from NPWT patients (n = 23) to demonstrate the presence of DSWI using reticulated polyurethane sponge culture, a swab, and blood culture. In 2015, a new collection device was introduced for specimen collection. A total of 357 samples (n = 17) were collected using the ESwab(™) (Copan, Murrieta, CA) for deep and superficial wound sample collection. In addition, blood culture devices were used for collecting mediastinal fluid aspirated directly from the wound and biologic fluid obtained from the NPWT device. Fisher exact test was performed to test the rate of independence rate of micro-organism identification using the NPWT sponge device and taking blood culture results as a reference for micro-organism identification.

RESULTS

After the introduction of the new collection device in our hospital, an overall increase in the detection of micro-organisms (46.7%) was reported. During 2013-2014 our traditional microbiologic collection method did not detect a pathogen in 30.4% of patients. During 2015, the new sample collection approach, direct from the NPWT device, improved micro-organism detection by 10.4% and reduced DSWIs with undetected pathogens to 17.6% (p < 0.01).

CONCLUSIONS

As a result of proficiency gained in the last year, the most representative specimen in wound infection was represented by mediastinal fluid collected directly from the wound and the NPWT device. Given the correlation between the blood culture of micro-organisms detected using the ESwab device from the wound, mediastinal drainage, and drainage from the NPWT device, we can assume that the NPWT device may replace the other biologic sampling devices.

A National Study of the Impact of Initial Débridement Timing on Outcomes for Patients with Deep Sternal Wound Infection

BACKGROUND

Excisional débridement for patients with deep sternal wound infection is a main component of treatment. This study aims to evaluate the impact of delayed excisional débridement on mortality and associated outcomes.

METHODS

The authors analyzed the MarketScan database from 2009 to 2013 to identify patients with deep sternal wound infection who received surgical intervention. A logistic regression model was created to model mortality. Poisson regression models were used to model number of procedures, number of hospitalizations, and length of stay. A log-linear regression model was used for cost analysis. All analyses were adjusted for patient risk factors.

RESULTS

The final cohort included 1335 patients with 12 percent in-hospital mortality. There was considerable variation in timing of débridement among patients with deep sternal wound infection, with more than 25 percent undergoing initial débridement 4 or more days after diagnosis, and 10 percent undergoing débridement more than 1 week after diagnosis. Patients undergoing delayed débridement had progressively higher risk for greater number of admissions and total hospital days compared with those undergoing early débridement. Patients undergoing débridement on the day of diagnosis of deep sternal wound infection had a predicted 34 total hospital days, compared with 49 total hospital days for patients undergoing débridement more than 7 days after diagnosis.

CONCLUSIONS

Patients treated with early surgical intervention had fewer hospital admissions and fewer hospital days than patients undergoing delayed surgical treatment. Protocols to facilitate early débridement have the potential to improve quality and efficiency of deep sternal wound infection care.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Therapeutic Outcomes of Pectoralis Major Muscle Turnover Flap in Mediastinitis

Background

This study aimed to evaluate the therapeutic results and safety of pectoralis major muscle turnover flaps in the treatment of mediastinitis after coronary artery bypass grafting (CABG) procedures.

Methods

Data regarding 33 patients with post-CABG deep sternal wound infections (DSWIs) who underwent pectoralis major muscle turnover flap procedures in the Emam Reza and Ghaem Hospitals of Mashhad, Iran were reviewed in this study. For each patient, age, sex, hospital stay duration, remission, recurrence, and associated morbidity and mortality were evaluated.

Results

Of the 2,447 CABG procedures that were carried out during the time period encompassed by our study, DSWIs occurred in 61 patients (2.5%). Of these 61 patients, 33 patients (nine females [27.3%] and 24 males [72.7%]) with an average age of 63±4.54 years underwent pectoralis major muscle turnover flap placement. Symptoms of infection mainly occurred within the first 10 days after surgery (mean, 10.24±13.62 days). The most common risk factor for DSWIs was obesity (n=16, 48.4%) followed by diabetes mellitus (n=13, 39.4%). Bilateral and unilateral pectoralis major muscle turnover flaps were performed in 20 patients (60.6%) and 13 patients (39.4%), respectively. Complete remission was achieved in 25 patients (75.7%), with no recurrence in the follow-up period. Four patients (12.1%) needed reoperation. The mean hospitalization time was 11.69±6.516 days. Four patients (12.1%) died during the course of the study: three due to the postoperative complication of respiratory failure and one due to pulmonary thromboembolism.

Conclusion

Pectoralis major muscle turnover flaps are an optimal technique in the treatment of post-CABG mediastinitis. In addition to leading to favorable therapeutic results, this flap is associated with minimal morbidity and mortality, as well as a short hospitalization time.

Determining risk factors for surgical wound dehiscence: a literature review

Postoperative wound healing plays a significant role in facilitating a patient's recovery and rehabilitation. Surgical wound dehiscence (SWD) impacts on mortality and morbidity rates and significantly contributes to prolonged hospital stays and associated psychosocial stressors on individuals and their families. A narrative review of SWD was undertaken on English-only studies between 1945 and 2012 using three electronic databases Ovid CINHAL, Ovid Medline and Pubmed. The aim of this review was to identify predisposing factors for SWD and assessment tools to assist in the identification of at-risk patients. Key findings from the included 15 papers out of a search of 1045 revealed the most common risk factors associated with SWD including obesity and wound infection, particularly in the case of abdominal surgery. There is limited reporting of variables associated with SWD across other surgical domains and a lack of risk assessment tools. Furthermore, there was a lack of clarity in the definition of SWD in the literature. This review provides an overview of the available research and provides a basis for more rigorous analysis of factors that contribute to SWD.

Self-reported physical activity and lung function two months after cardiac surgery--a prospective cohort study

BACKGROUND

Physical activity has well-established positive health-related effects. Sedentary behaviour has been associated with postoperative complications and mortality after cardiac surgery. Patients undergoing cardiac surgery often suffer from impaired lung function postoperatively. The association between physical activity and lung function in cardiac surgery patients has not previously been reported.

METHODS

Patients undergoing cardiac surgery were followed up two months postoperatively. Physical activity was assessed on a four-category scale (sedentary, moderate activity, moderate regular exercise, and regular activity and exercise), modified from the Swedish National Institute of Public Health's national survey. Formal lung function testing was performed preoperatively and two months postoperatively.

RESULTS

The sample included 283 patients (82% male). Two months after surgery, the level of physical activity had increased (p < 0.001) in the whole sample. Patients who remained active or increased their level of physical activity had significantly better recovery of lung function than patients who remained sedentary or had decreased their level of activity postoperatively in terms of vital capacity (94 ± 11% of preoperative value vs. 91 ± 9%; p = 0.03), inspiratory capacity (94 ± 14% vs. 88 ± 19%; p = 0.008), and total lung capacity (96 ± 11% vs. 90 ± 11%; p = 0.01).

CONCLUSIONS

An increased level of physical activity, compared to preoperative level, was reported as early as two months after surgery. Our data shows that there could be a significant association between physical activity and recovery of lung function after cardiac surgery. The relationship between objectively measured physical activity and postoperative pulmonary recovery needs to be further examined to verify these results.

Ozone therapy as an adjunct to vancomycin enhances bacterial elimination in methicillin resistant Staphylococcus aureus mediastinitis

BACKGROUND

We aimed to investigate the influence of intraperitoneal ozone therapy on bacterial elimination and mediastinal inflammation in experimental Staphylococcus aureus mediastinitis.

MATERIALS AND METHODS

Forty Wistar-Albino rats were randomized into five groups (eight per group) as follows: uncontaminated group, untreated contaminated group, ozone group, vancomycin group, and vancomycin + ozone group. Uncontaminated group underwent upper median sternotomy. The remaining four groups were inoculated with 0.5 mL 10(8) colony-forming units/mL methicillin-resistant Staphylococcus aureus in the mediastinal and sternal layers. Untreated contaminated group had no treatment. Rats in the vancomycin group received intramuscular vancomycin (40 mg/kg/d), and ozone was administered intraperitoneally (70 μg/mL, 1 mg/kg/d) in the ozone group for the treatment of mediastinitis. Vancomycin + ozone group rats were treated by the combination of both methods. At the end of 10 d, quantitative bacterial cultures and sternal tissue samples were obtained for determination of bacterial counts and histologic degree of inflammation.

RESULTS

Both the vancomycin and the ozone treatments caused significant reduction of bacterial counts in quantitative bacterial cultures. Combination of vancomycin and ozone treatments resulted in further reduction of bacterial counts in mediastinum and sternum. Histologic examination of tissue samples revealed significant reduction in severity of mediastinitis related inflammation in vancomycin and vancomycin + ozone groups compared with untreated contaminated group.

CONCLUSIONS

Ozone therapy as an adjunct to vancomycin leads to enhanced bacterial elimination in infected sternal and mediastinal tissues in experimental methicillin-resistant Staphylococcus aureus mediastinitis. The benefit of adjuvant ozone therapy is suggested to be related to its bactericidal effect.

Deep sternal wound complications: an overview of old and new therapeutic options

Deep sternal wound complications represent a significant problem in current open heart surgery and still pose a tremendous challenge to surgeons. Over the years, many treatment modalities have been proposed, but only few found their way into daily clinical practice of cardiothoracic surgeons. A gold standard has not been defined yet. This review was designed to give an overview of the preferred surgical strategies.