A retrospective study of deep sternal wound infections: clinical and microbiological characteristics, treatment, and risk factors for complications

Surgical Site Infections Complicating Coronary Artery Bypass Graft Surgery in Australia: time trends in infection rates, surgical antimicrobial prophylaxis and pathogens using a comprehensive surveillance network, 2010-2023

BACKGROUND

This study reports trends in the epidemiology of surgical site infections (SSI) complicating coronary artery bypass graft (CABG) surgery and describes changes in surgical antimicrobial prophylaxis (SAP) compliance and causative pathogens over time.

METHODS

Data on CABG procedures from 2010 to 2023 submitted to the Victorian healthcare-associated infection surveillance coordinating centre were analyzed. Trends in the SSI rate and choice, timing and duration of SAP were modelled using Poisson regression. The most common pathogens causing SSI and their change over time were assessed.

RESULTS

32,446 CABG procedures were reported during the study period. Sternal SSI rate decreased from 2.7 per 100 procedures in 2010 to 1.6 per 100 procedures in 2023, representing a 15% annual decrease when the model was adjusted for the number of years of participation in surveillance. This decrease was most marked during the first decade (IRR 0.70 [95% CI 0.64, 0.76]) followed by stable rates between 2020 and 2023 (IRR 1.08 [95% CI 0.93, 1.27]). Compliance with SAP choice was consistently above 98%, while compliance with timing increased by an average of 1% per year to 83%, and compliance with duration fluctuated between 75% and 86%. The most frequent pathogens responsible for SSI were Staphylococcus aureus, Serratia marcescens, Staphylococcus epidermidis, and Klebsiella pneumoniae. The proportion of sternal and donor site SSIs involving Gram-negative pathogens increased from 38% to 59%.

CONCLUSION

This analysis of 14 years of surveillance data for SSI complicating CABG procedures highlighted a reduction in rates of SSI, high rates of compliance with antimicrobial choice for SAP, and predominance of S. aureus as a causative pathogen of SSI in our region. Notably, we observed Gram-negative pathogens, particularly S. marcescens, to be responsible for a larger proportion of SSIs over recent years.

Randomized Controlled Trial: Does the Use of Occlusive Hydrocolloid Silver-Containing Wound Dressing after Sternotomy Reduce Surgical Site Infection after Cardiac Surgery?

(1) Background: To reduce the incidence of surgical site infections (SSIs) following median sternotomy in cardiac surgery, we compared an occlusive hydrocolloid silver-containing wound dressing (OHSCWD) with a standard wound dressing. (2) Methods: This study was designed as a single-center randomized controlled trial. The primary endpoint was the overall rate of incidence of any kind of SSI. Secondary endpoints were the number of dressing changes, the severity of SSIs, and whether there was a need for treatment. Wounds were monitored daily until the seventh and on the 30th postoperative day. (3) Results: Of the 423 patients included, 352 were analyzed. No differences in demographics, cardiovascular risk factors, intraoperative processes, and postoperative care were found between both groups. Additionally, the incidence or extent of SSI showed no significant differences between the two groups. (4) Conclusions: In summary, out of all pre-, intra-, and postoperative factors, the contribution of postoperative wound care to the development of SSIs appears to play a subordinate role. However, by offering equivalent wound protection and a reduced number of dressing changes, OHSCWD after median sternotomy in cardiac surgery patients could be a good alternative to standard dressings from the point of view of the patient, the staff, and the clinic.

Antibiotic-loaded bone cement fixation technique combined with bilateral pectoralis major muscle flaps tension-free management for sternal infection after midline sternotomy

INTRODUCTION

Deep sternal wound infection (DSWI) after midline sternotomy of cardiac surgery is a challenging complication that affects the outcome of surgery. This study aims to assess the clinical effectiveness of the antibiotic-loaded bone cement fixation technique combined with bilateral pectoralis major muscle flaps tension-free management in the treatment of DSWI.

METHODS

We retrospectively analyzed 5 patients with DSWI who underwent antibiotic-loaded bone cement combined with bilateral pectoralis major muscle flaps for chest wall reconstruction after sternotomy for cardiac surgery in a tertiary hospital in China from January 2020 to December 2021. The clinical and follow-up data were retrospectively analyzed.

RESULTS

All patients had no perioperative mortalities, no postoperative complications, 100% wound healing, and an average hospital stay length of 24 days. The follow-up periods were from 6 to 35 months (mean 19.6 months). None of the cases showed wound problems after initial reconstruction using antibiotic-loaded bone cement combined with bilateral pectoralis major muscle flaps.

CONCLUSIONS

We report our successful treatment of DSWI, using antibiotic-loaded bone cement fixation technique combined with bilateral pectoralis major muscle flaps tension-free management. The clinical and follow-up results are favorable.

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.

The use of flaps for management of deep sternal wound complications: A systematic review and meta-analysis

BACKGROUND

Many options are available for reconstruction after deep sternal wound infections. However, these options have not been critically appraised. The aim of this systematic review and meta-analysis was to assess the existing evidence on sternal rewiring versus flap reconstruction and pectoralis major muscle flaps (PMFs) versus greater omental flaps (GOFs).

METHODS

A systematic review and meta-analysis was performed. CENTRAL, MEDLINE and EMBASE were searched. Outcomes of interest included mortality, treatment failure and length of hospital stay (LOS).

RESULTS

Fourteen studies were included. Nine studies compared flaps to rewiring, reporting on 618 patients. Patients treated with flaps had significantly lower mortality compared with patient treated with rewiring (Risk ratio [RR] 0.42, 95% confidence interval [CI]: 0.23-0.77, P < 0.01). Flap patients had significantly lower treatment failure compared with those who were treated with rewiring (RR 0.22, 95% CI: 0.14-0.37, P < 0.01). No statistically significant differences were observed in LOS between patients treated with flaps compared those treated with rewiring (standard mean difference -0.84, 95% CI: -1.91 to 0.24, P = 0.13). Five studies compared PMF with GOF, reporting on 599 patients. No statistically significant differences were found in mortality (RR 0.63, 95% CI: 0.24-1.68, P = 0.36), LOS (standard mean difference -14.52, 95% CI: -42.00 to 12.96, P = 0.30) or treatment failure (RR 1.37, 95% CI: 0.31-6.07, P = 0.68) in patients treated with PMF compared with patients treated with GOF.

CONCLUSIONS

Flap-based reconstruction demonstrated improved mortality and treatment outcomes compared to sternal rewiring. However, no significant differences were observed in outcomes between the PMF- and GOF-based reconstructions.

Extended arc of rotation of Latissimus Dorsi Musculocutaneous Flap providing well-vascularized tissue for reconstruction of complete defects of the sternum: An anatomical study of flap pedicle modification

BACKGROUND

Deep sternal wound infections (DSWI) following cardiothoracic surgery represent a life quality endangering sequelae and may lead to sternal osteomyelitis. Radical debridement followed by Negative Pressure Wound Therapy (NPWT) may achieve infection control, provide angiogenesis, and improve respiratory function. When stable wound conditions have been established a sustainable plastic surgical flap reconstruction should be undertaken.

OBJECTIVE

This study analyses a method to simplify defect coverage with a single Latissimus Dorsi Myocutaneous Flap (LDMF).

METHODS

Preparation of 20 LDMF in ten fresh frozen cadavers was conducted. Surgical steps to increase pedicle length were evaluated. The common surgical preparation of LDMF was compared with additional transection of the Circumflex Scapular Artery (CSA).

RESULTS

Alteration of the surgical preparation of LDMF by sacrificing the CSA may provide highly valuable well-vascularized muscle tissue above the sensitive area of the Xiphisternum. All defects could be completely reconstructed with a single LDMF. The gain in length of flap tissue in the inferior third of the sternum was 3.86±0.9 cm (range 2.2 to 8 cm).

CONCLUSIONS

By sacrificing the CSA in harvesting the LDMF a promising gain in length, perfusion and volume may be achieved to cover big sternal defects with a single flap.

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.

The role of negative pressure wound therapy in the treatment of poststernotomy mediastinitis in Asians: A single-center, retrospective cohort study

Introduction

Poststernotomy mediastinitis (PSM) is a critical and life-threatening complication that can arise after cardiac surgery. The aim of this study was to evaluate and compare the outcomes of negative pressure wound therapy (NPWT) and conventional methods in the management of mediastinitis following heart surgery with a focus on Asian populations.

Methods

For this retrospective study, we included and evaluated a total of 34 patients who had undergone cardiac operations between January 2011 and September 2021 and developed PSM. The patients were divided into two groups, the NPWT group (n = 16, 47.1%) and the conventional treatment group (n = 18, 52.9%), and compared.

Results

The two groups showed no significant differences in terms of patient characteristics, PSM wound classification based on the El Oakley classification, and wound closure methods, but there was a higher incidence of diabetes mellitus in the NPWT group. With regard to mediastinal cultures, a higher prevalence of Staphylococcus epidermidis was observed in the NPWT group. However, we found no significant differences between the two groups regarding the time interval from diagnosis to wound closure, hospitalization duration, and re-exploration rate. Notably, the NPWT group exhibited a significantly higher in-hospital mortality rate than the conventional treatment group (p = 0.024).

Conclusions

Our findings suggest that the use of NPWT might not lead to improved medical outcomes for patients with PSM when compared to conventional treatment methods. As a result, it becomes imperative to exercise great care when choosing patients for NPWT. To obtain more definitive and conclusive results and identify the most appropriate cases for NPWT, conducting larger randomized clinical trials is necessary.

Surgical Site Infection in Cardiac Surgery

Surgical site infections (SSIs) are one of the most significant complications in surgical patients and are strongly associated with poorer prognosis. Due to their aggressive character, cardiac surgical procedures carry a particular high risk of postoperative infection, with infection incidence rates ranging from a reported 3.5% and 26.8% in cardiac surgery patients. Given the specific nature of cardiac surgical procedures, sternal wound and graft harvesting site infections are the most common SSIs. Undoubtedly, DSWIs, including mediastinitis, in cardiac surgery patients remain a significant clinical problem as they are associated with increased hospital stay, substantial medical costs and high mortality, ranging from 3% to 20%. In SSI prevention, it is important to implement procedures reducing preoperative risk factors, such as: obesity, hypoalbuminemia, abnormal glucose levels, smoking and S. aureus carriage. For decolonisation of S. aureus carriers prior to cardiac surgery, it is recommended to administer nasal mupirocin, together with baths using chlorhexidine-based agents. Perioperative management also involves antibiotic prophylaxis, surgical site preparation, topical antibiotic administration and the maintenance of normal glucose levels. SSI treatment involves surgical intervention, NPWT application and antibiotic therapy.

Nosocomial Extracardiac Infections After Cardiac Surgery

Purpose of Review

Nosocomial extracardiac infections after cardiac surgery are a major public health issue affecting 3–8.2% of patients within 30–60 days following the intervention.

Recent Findings

Here, we have considered the most important postoperative infective complications that, in order of frequency, are pneumonia, surgical site infection, urinary tract infection, and bloodstream infection. The overall picture that emerges shows that they cause a greater perioperative morbidity and mortality with a longer hospitalization time and excess costs. Preventive interventions and corrective measures, diminishing the burden of nosocomial extracardiac infections, may reduce the global costs. A multidisciplinary team may assure a more appropriate management of nosocomial extracardiac infections leading to a reduction of hospitalization time and mortality rate.

Summary

The main and most current data on epidemiology, prevention, microbiology, diagnosis, and management for each one of the most important postoperative infective complications are reported. The establishment of an antimicrobial stewardship in each hospital seems to be, at the moment, the more valid strategy to counteract the challenging problems.

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 Analysis of 400 Sternal Wound Reconstructions at a Single Institution: Bacterial Pathogens Vary With Time

BACKGROUND

Sternal wound (SW) infection and dehiscence after median sternotomy from cardiac surgery remain challenging complications with high morbidity. Knowledge of common pathogen types and variance with time from cardiac surgery can simplify the choice of antibiotics while awaiting definitive culture results.

METHODS

Records of 505 patients undergoing SW reconstruction by the senior author from 1996 to 2018 at a high-volume cardiac surgery center were reviewed. The most common indications for reconstruction were SW infection and dehiscence. At surgery, all patients underwent removal of sternal hardware, thorough debridement, and closure with bilateral pectoralis major myocutaneous advancement flaps. Deep tissue and bone cultures were sent in nearly all cases. Patients were split into group 1 or group 2 based on timing of flap reconstruction after initial cardiac surgery: 0 to 30 days and longer than 30 days, respectively.

RESULTS

Complete data were available for 400 SW procedures performed during this period. Group 1 included 203 patients, and group 2 had 197 patients, with a mean time to SW surgery of 16.3 and 138.1 days, respectively. Intraoperative cultures were positive in 147 of 203 (72.4%), and 122 of 197 (61.9%) patients, respectively. Forty-four patients grew polymicrobial cultures. There was a significant difference in culture positivity rates in the 2 groups (P = 0.0004). The most common bacteria cultured in group 1 was Staphylococcus epidermidis (54 of 203 vs 21 of 197; P < 0.0001), whereas methicillin-sensitive Staphylococcus aureus was most common in group 2 (15 of 203 vs 22 of 197; P = 0.23). Methicillin-resistant S. aureus was relatively common in both groups (17 of 203 vs 21 of 197; P = 0.50). Although not statistically significant, Pseudomonas, Klebsiella, and Candida were all found in a higher percentage of patients in group 2 (p = 0.11, 0.20, 0.20).

CONCLUSIONS

Microbial species cultured in SW flap reconstruction vary over time. Staphylococcus epidermidis is the most common infectious agent in patients having reconstruction within 30 days of cardiac surgery, whereas methicillin-sensitive S. aureus is most common after 30 days. The trend toward a higher incidence of Gram-negative and fungal organisms after 30 days may indicate a need for broader initial anti-infective coverage in this patient group. Awareness of these pathogen patterns can better inform antibiotic selection while awaiting culture data.

Efficacy and safety of pectoralis muscle flap combined rectus abdominis muscle sheath fasciocutaneous flap for reconstruction of sternal infection

Few studies have assessed the efficacy and safety of reconstruction of sternal infection using a pectoralis muscle flap combined with a rectus abdominis muscle (RAM) sheath fasciocutaneous flap. We report here our experience with this procedure to reconstruct the sternal defect in patients (n = 46) with a deep sternal wound infection (DSWI) after cardiac surgery. After wound reconstruction, the proportion of prolonged mechanical ventilation use and intensive care unit (ICU) stay were 17.4% (n = 8) and 21.7% (n = 10), respectively. The 30‐day all‐cause mortality was 15.2%; recurrence rate was 17.4%; postoperative complications were 15.2%; and median hospital stay was 31 (0‐157) days. Multivariate logistic regression analysis revealed that hypertension (β = 21.32, 95%CI 4.955‐37.68, P = .014), drainage‐tube use (β = 0.944, 95%CI 0.273‐1.614, P = .008), and prolonged intensive care unit stay (β = 53.65, 95%CI 31.353‐75.938, P < .001) were significantly correlated with hospital stay. In conclusion, a procedure including surgical debridement, sternal reconstruction with bilateral PM and RAM sheath flap, long‐term antibiotics, and adequate drainage is a beneficial technique in the reconstruction of deep sternal wound infection after cardiac surgery. Duration of drainage tube use may be as an index for a hospital stay or wound healing.

Anaesthesia Challenges during Sternal Wound Debridement

A 50-year-old female weighing 80 kg is posted for a deep sternal wound debridement, post mitral valve replacement (MVR), and post-CABG (Coronary Artery Bypass Grafting) (left internal mammary artery (LIMA)→left anterior descending (LAD)). She had sternal osteomyelitis and had wound debridement thrice before. She had also history of cardiac injury repair during second wound debridement.

Her initial three tissue cultures showed Acinetobacter positive. Her fourth tissue culture shows Staphylococcus haemolyticus positive. Histopathology shows necrotizing granuloma. Two-dimensional Echocardiography (ECHO) shows post-MVR, no Mitral regurgitation (MR), mild Tricuspid Regurgitation (TR) (right ventricular systolic pressure (RVSP)-24 + Retrograde autologous priming (RAP)), Inferior Vena Cava #x0028;IVC) 1.6 cm with respiratory collapse, no pericardial effusion, no Left atrium (LA) clot/veg, and normal biventricular function.

Gram-negative bacteria as a cause of mediastinitis after cardiac surgery

PURPOSE OF REVIEW

Poststernotomy mediastinitis (PSM) remains a serious infection and is significantly associated with high morbidity, short-term and long-term mortality. Gram-negative bacteria (GNB) are an underestimated cause of PSM, and there is little information on the risk factors, prevention, diagnosis and management of GNB PSM.

RECENT FINDINGS

The pathogenesis of PSM is the result of a complex and multifactorial interplay between intraoperative wound contamination, host-related and surgical host factors but GNB are probably mostly translocated from other host site infections. GNB are frequent cause of PSM (18-38% of cases) and GNB PSM have shown to more frequently polymicrobial (20-44%). GNG PSM has shown to occur earlier than Gram-positive PSM. Early diagnosis is crucial to successful treatment. The management of PSM needs a combination of culture-directed antimicrobial therapy and an early extensive surgical debridement with either immediate or delayed closure of the sternal space. Antibiotic treatment choice and duration should be based on clinical evaluation, evolution of inflammatory markers, microbiological tests and imaging studies. Mortality has shown to be significantly higher with GNB PSM compared with other causes and the inappropriateness of initial antibiotic therapy may explain the worse outcome of GNB PSM.

SUMMARY

GNB PSM is usually undervalued in the setting of PSM and have shown to be a frequent cause of inappropriate treatment with adverse prognostic potential. There is a need for efforts to improve knowledge to prevent and adequately treat GNB PSM.

Prevention, Diagnosis and Management of Post-Surgical Mediastinitis in Adults Consensus Guidelines of the Spanish Society of Cardiovascular Infections (SEICAV), the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) and the Biomedical Research Centre Network for Respiratory Diseases (CIBERES)

This is a consensus document of the Spanish Society of Cardiovascular Infections (SEICAV), the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) and the Biomedical Research Centre Network for Respiratory Diseases (CIBERES). These three entities have brought together a multidisciplinary group of experts that includes anaesthesiologists, cardiac and cardiothoracic surgeons, clinical microbiologists, infectious diseases and intensive care specialists, internal medicine doctors and radiologists. Despite the clinical and economic consequences of sternal wound infections, to date, there are no specific guidelines for the prevention, diagnosis and management of mediastinitis based on a multidisciplinary consensus. The purpose of the present document is to provide evidence-based guidance on the most effective diagnosis and management of patients who have experienced or are at risk of developing a post-surgical mediastinitis infection in order to optimise patient outcomes and the process of care. The intended users of the document are health care providers who help patients make decisions regarding their treatment, aiming to optimise the benefits and minimise any harm as well as the workload.

Abdominal-based adipocutaneous advancement flap for reconstructing inguinal defects with contraindications to standard reconstructive approaches: a simple and safe salvage reconstructive option

BACKGROUND

Groin wounds occurring after vascular surgical site infection, oncologic resection, or occasionally orthopedic surgery and trauma may represent a surgical challenge. Reconstruction of these defects by the usual workhorse flaps may be contraindicated following previous surgery and in patients with lower limb lymphedema or extreme morbidity.

METHODS

This study included 15 consecutive patients presenting with inguinal wounds after vascular or general surgery that required debridement and soft tissue coverage. All cases had absolute or relative contraindications to conventional reconstructive techniques, including a compromised deep femoral artery network, limb lymphedema, scarring of potential flap harvesting sites, or poor overall condition. Abdominal adipocutaneous excess enabled the performance of adipocutaneous advancement flaps in an abdominoplasty-like fashion. Immediate and long-term outcomes were analyzed.

RESULTS

Soft tissue coverage was effective in all cases. Two patients required re-intervention due to flap-related complications (venous congestion and partial flap necrosis). All patients fully recovered over a mean±standard deviation follow-up of 2.4±1.5 years.

CONCLUSIONS

Abdominal flaps can be an effective and simple alternative technique for inguinal coverage with reproducible outcomes. In our experience, the main indications are a compromised deep femoral artery network and poor thigh tissue quality. Relative contraindications, such as previous open abdominal surgery, should be considered.

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.

[Deep sternal wound infection after sternotomy - Report of the consensus workshop of the German-Speaking Society for Microsurgery of Peripheral Nerves and Vessels (DAM)]

Deep sternal wound infection (TSWI) is a potentially life-threatening complication that may occur after median sternotomy, contributing to prolonged hospital stay and increased health care costs. Bacterial infection is often characterized by biofilm formation on implant material and/or dead bone. Diagnosis is made upon clinical signs and symptoms of local and systemic infection. Early multidisciplinary decision making is needed for optimal patient care. Repeated surgical wound debridements accompanied by wound conditioning are performed until clean circumstances are achieved. Thereafter, wound closure and defect reconstruction are obtained using a variety of pedicled and microvascular flaps.

The Characteristics of Postoperative Mediastinitis During the Changing Phases of Cardiac Surgery

BACKGROUND

Mediastinitis is a serious complication of open heart surgery associated with high mortality, considerable health care costs, and prolonged hospital stay. We examined characteristics and incidence of mediastinitis during 29 years when indications and patient material have been in a process of change.

METHODS

This was a retrospective population-based study comprising all mediastinitis patients more than 16 years of age after open heart surgery between 1990 and 2018 from a population of 1.7 million. Patient records of 50 mediastinitis patients from 2004 to 2014 were reviewed and compared with 120 patients from 1990 to 1999.

RESULTS

Annual mediastinitis rate varied 0% to 1.5% with a decreasing trend-from a level exceeding 1.2% to approximately 0.3%-over the study period. In 2004 to 2014 patients with mediastinitis were older, more often smokers, and more often had diabetes mellitus and renal insufficiency than in 1990 to 1999. No difference in length of hospital treatment, antibiotic prophylaxis or treatment, intensive care unit treatment, or mortality was observed between 1990 to 1999 and 2004 to 2014. Coronary artery bypass graft surgery became less common and valve replacement and hybrid operations more common among operations leading to mediastinitis. Staphylococcus aureus increased (from 25% to 56%, p = .005) whereas coagulase-negative staphylococci (46% to 23%, P < .001) and gram-negative bacteria (18% to 12%, P = .033) decreased as causative agents. Surgery for mediastinitis remained similar except introduction of vacuum-assisted closure treatment.

CONCLUSIONS

The rate of mediastinitis decreased during these 29 years. No difference in 30-day mortality in mediastinitis was seen: 0.9% in 1990 to 1999 and 2% in 2004 to 2014.

[Negative pressure wound therapy for deep sternal wound infections: microbiological characteristics and antibiotic resistance]

OBJECTIVE

To evaluate bacterial flora in patients with deep sternal wound infection and the effect of negative pressure wound therapy on eradication of the pathogen.

MATERIAL AND METHODS

There were 102 patients with deep wound infection after cardiac surgery. Mean age was 66.9±9.9 years. Diabetes mellitus was detected in 21 (20.5%) cases, chronic obstructive pulmonary disease - in 15 (14.7%). Wound debridement via daily dressings was performed in 64 patients; vacuum-assisted dressings were applied in 38 patients. Bacteriological analysis of discharge was carried out every week.

Results. Mixed infection was observed in 38 (37.3%) patients. S.aureus was the most common pathogen (n=51, 50%), Gram negative bacteria were found in 36 (35.3%) patients. Negative pressure wound therapy ensured eradication of S.aureus within 3 weeks while dressings were associated with only 40% decrease of the incidence of positive analyses (p<0.05). Effectiveness of the method was not obtained for Gram negative bacteria.

CONCLUSION

Negative pressure wound therapy accelerates eradication of Gram positive pathogens but does not affect eradication of Gram negative microbes.

Right Ventricle Rupture After Open Heart Surgery

The potential complications of cardiac surgery with sternotomy include mediastinitis and major bleeding, events that are infrequent but carry high mortality.We report a unique complication of median sternotomy. A 71-year-old man underwent coronary artery bypass grafting complicated by sternal dehiscence on postoperative day 7. One week after discharge, he presented with purulent drainage from the sternal wound bed and was diagnosed as having mediastinitis. Irrigation, debridement, and sternal reconstruction were performed. Two days later, bleeding was observed in the wound, and during surgical exploration, a tear in the right ventricle was discovered, and the patient exsanguinated and died. Autopsy findings included focal adhesions connecting the posterior sternum to the right ventricle wall, as well as microscopic evidence of focally extensive fatty infiltration along the rupture margin of the myocardium.Pertinent aspects of the case are reviewed, with particular attention to the possible microbial etiology of mediastinal infection and most likely mechanisms of injury contributing to the fatal right ventricular rupture.

Sternal Wound Complications: Results of Routine Use of Negative Pressure Wound Therapy

INTRODUCTION

Negative pressure wound therapy (NPWT) has significantly improved outcomes in individuals with superficial and deep sternal wound dehiscence (SWD). We report our experience with NPWT to evaluate factors influencing effectiveness, duration of treatment and postoperative hospital stay.

METHODS

We reviewed 92 patients with postoperative SWD following a median sternotomy. Patients were divided into 2 groups: those with a superficial SWD (Group 1; 72, 78%) and those with a deep SWD (Group 2; 20, 28%). Group 1 was further divided into 3 subgroups based on NPWT duration.

RESULTS

In both groups, none of the preoperative characteristics examined showed a significant association with longer NPWT duration. In Group 2, there was a trend for postoperative bleeding and neurological complications to be associated with longer treatment duration. In the entire series, staph infection resulted a weak predictor of NPWT duration. In each Group 1 subgroup and in Group 2, treatment days were compared with duration of hospitalization until discharge. Mean post-NPWT hospital stay was 6 days in subgroup 1, 12 days in subgroup 2 and 20 days in subgroup 3 (P<0.0001). At a median 3-year follow-up, there were 4 late deaths, none related to wound complications. No cases of SWD recurrence were observed.

CONCLUSION

Our results confirm the effectiveness of NPWT in SWD management, while excessive treatment duration might have a negative impact on the length of hospital stay. Further studies are needed to define an optimal use of NPWT protocol.

Sequential antimicrobial therapy in mediastinitis after cardiac surgery: An observational study of 81 cases

INTRODUCTION

Mediastinitis is an infrequent but serious complication of cardiac surgery. Antimicrobial treatment guidelines are not well established. The aim was to describe the efficacy of sequential intravenous to oral therapy in selected post-surgical mediastinitis patients.

METHODS

A retrospective observational study including cases of mediastinitis after cardiac surgery, defined according to CDC criteria, at a third-level university hospital between January 2002 and December 2016. Sequential antimicrobial therapy was proposed in clinically stable patients. Rates of cure, relapse, and hospital stay were compared between patients who received sequential intravenous to oral therapy and those who received therapy exclusively by the intravenous route.

RESULTS

Eighty-one cases were included. Sequential intravenous to oral therapy was performed in 48 (59.3%) patients on median day 15. No differences in baseline characteristics or causal microorganisms were found between the two cohorts. The average duration of antibiotic therapy was 41.2±10.09 days. The most commonly used drugs in sequential therapy were quinolones in 31 (64.6%) cases and rifampicin, always in association with another antibiotic, in 25 (52.1%). Hospital stay was shorter in the sequential therapy group (57.57±34.03 vs. 84.35±45.67; P=0.007). Cure was achieved in 77 (92.8%) patients. Overall in-hospital mortality was less frequent in the group that received sequential therapy (2.1% vs. 15.2%; P=0.039). There were no differences in relapse between the two cohorts (4.2% vs 9.1%; P=0.366).

CONCLUSION

Sequential antimicrobial treatment in selected patients with post-surgical mediastinitis may be as effective as exclusively intravenous treatment, reducing risks, hospital stay and associated costs.

Clinical and Microbiological Analysis of Deep Sternal Wound Infections in Fifty-Two Consecutive Patients

Background: Mediastinitis after cardiac surgery can lead to devastating consequences such as deep sternal wound infections (DSWI). Staphylococcus epidermidis and other coagulase-negative staphylococci belong to the physiological skin flora and therefore generally are not considered pathogenic agents. Thus, local resistance patterns of these bacterial species often recovered from wound specimens generally are ignored while choosing antibiotics for peri-operative prophylaxis in cardiac surgery as well as in the selection of empiric antibiotic therapy of DSWI. Methods: During the period May 2012-May 2013, 52 patients suffering from DSWI were treated at our institution. For every patient, deep tissue samples were obtained during surgical debridement procedures and submitted to microbiologic analysis. The frequency of and the time to occurrence of a DSWI was recorded, and baseline data, previous operative interventions, complications, and the technique used for soft tissue reconstruction, as well as the microbiologic results and individual risk factors, were documented. Results: There were 32 male patients (62%) and 20 female. The patients' age at the time of revision was a mean of 67 ± 11.5 years (range 35-83 years). There was bacterial growth in 31 cases (60%), the predominant species being S. epidermidis (20 patients; 65%). Extended antibiotic therapy was indispensable to controlling the infection. Conclusion: The local resistance patterns of antibiotics should have a greater influence on the standardized prophylaxis or empirical therapy of DSWI and need to be discussed specifically for this high-risk population. Because of its multi-resistance spectrum, S. epidermidis must be classified as a potential pathogen. In the cases reported here, extended antibiotic therapy was necessary to support wound healing and thus good patient outcomes.

Epidemiology and outcome of Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-KP) infections in cardiac surgery patients: a brief narrative review

Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-KP) is a difficult-to-treat pathogen due to its multidrug-resistant phenotype. Cardiac surgery patients are at increased risk of developing KPC-KP infections compared to other populations, with previous KPC-KP colonization being a critical factor in influencing the risk of subsequent infection. Two different pieces of information are essential to comprehensively assess the local characteristics of KPC-KP colonization in cardiac surgery patients: (i) the local prevalence of colonization; (ii) the timing of colonization. Treatment of KPC-KP infections in cardiac surgery patients is a complex task, but more effective treatment options have recently become available. Nonetheless, implementation and full adherence to infection-control measures remain of pivotal importance for reducing the burden of KPC-KP infections in this peculiar population. The aim of this narrative review is to summarize the available literature on the epidemiology and outcome of KPC-KP infections in cardiac surgery patients.

Deep sternal wound infections: Evidence for prevention, treatment, and reconstructive surgery

Median sternotomy is the most popular approach in cardiac surgery. Post-sternotomy wound complications are rare, but the occurrence of a deep sternal wound infection (DSWI) is a catastrophic event associated with higher morbidity and mortality, longer hospital stays, and increased costs. A literature review was performed by searching PubMed from January 1996 to August 2017 according to the guidelines in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The following keywords were used in various combinations: DSWI, post-sternotomy complication, and sternal reconstruction. Thirty-nine papers were included in our qualitative analysis, in which each aspect of the DSWI-related care process was analyzed and compared to the actual standard of care. Plastic surgeons are often involved too late in such clinical scenarios, when previous empirical treatments have failed and a definitive reconstruction is needed. The aim of this comprehensive review was to create an up-to-date operative flowchart to prevent and properly treat sternal wound infection complications after median sternotomy.

Computed tomography improves the differentiation of infectious mediastinitis from normal postoperative changes after sternotomy in cardiac surgery

OBJECTIVES

To identify CT parameters independently associated with infectious mediastinitis after cardiac surgery and to improve the discrimination of patients with acute infection from those with normal postoperative changes.

METHODS

In this single-center, retrospective, observational cohort study, we evaluated thoracic CT scans of poststernotomy cardiac surgery patients. Inclusion criteria were clinically suspected mediastinitis, unclear CT signs (e.g., retrosternal mass), and subsequent deep revision surgery. Revision surgery and microbiological samples determined the mediastinitis status. Overall, 22 qualitative and quantitative CT imaging parameters were assessed and associated with infectious mediastinitis in univariate and multivariate regression models. Discriminative capacity and incremental value of the CT features to available clinical parameters were determined by AUC and likelihood-ratio tests, respectively.

RESULTS

Overall 105 patients (82% men; 67.0 ± 10.3 years) underwent CT and deep revision surgery. Mediastinitis was confirmed in 83/105 (79%) patients. Among available clinical parameters, only C-reactive protein (CRP) was independently associated with infectious mediastinitis (multivariate odds ratio (OR) (per standard deviation) = 2.3; p < 0.001). In the CT, the presence of free gas, pleural effusions, and brachiocephalic lymph node size were independently associated with mediastinitis (multivariate ORs = 1.3-6.3; p < 0.001-0.039). Addition of these CT parameters to CRP increased the model fit significantly (X² = 17.9; p < 0.001; AUC, 0.83 vs. 0.73).

CONCLUSION

The presence of free gas, pleural effusions, and brachiocephalic lymph node size in CT is independently associated with infectious mediastinitis in poststernotomy patients with retrosternal mass. These imaging features may help to differentiate mediastinitis from normal postoperative changes beyond traditional clinical parameters such as CRP.

KEY POINTS

• Presence of free gas, pleural effusions, and brachiocephalic lymph node size on CT are associated independently with infectious mediastinitis. • Combination of these CT parameters increases the discriminatory capacity of clinical parameters such as CRP.

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.

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

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Preliminary result with incisional negative pressure wound therapy and pectoralis major muscle flap for median sternotomy wound infection in a high-risk patient population

Deep sternal wound infection (DSWI) represents a dangerous complication that can follow open-heart surgery with median sternotomy access. Muscle flaps, such as monolateral pectoralis major muscle flap (MPMF), represent the main choices for sternal wound coverage and infection control. Negative pressure incision management system has proven to be able to reduce the incidence of these wounds' complications. Prevena™ represents one of these incision management systems and we aimed to evaluate its benefits. A total of 78 patients with major risk factors that presented post-sternotomy DSWI following cardiac surgery was selected. Thrity patients were treated with MPMF and Prevena™ (study group). Control group consisted of 48 patients treated with MPMF and conventional wound dressings. During the follow-up period, 4 (13%) adverse events occurred in the study group, whereas 18 complications occurred (37·5%) in the control group. Surgical revision necessity and mean postoperative time spent in the intensive care unit were both higher in the control group. Our results evidenced Prevena™ system's ability in improving the outcome of DSWI surgical treatment with MPMF in a high-risk patient population.

Orthopaedic biofilm infections

Many infections of the musculoskeletal system are biofilm infections that develop on non-living surfaces. Microorganisms adhere either on dead bone (sequesters) or implants. As a rule for a curative concept, chronic osteomyelitis or implant-associated bone infection must be treated with a combination of surgery and antimicrobial therapy. If an implant is kept in place, or a new device is implanted before complete healing of infection, a biofilm-active antibiotic should be used. Rifamycins are active against biofilms of staphylococci, and fluoroquinolones against those of Gram-negative bacilli. In this review, the management of chronic osteomyelitis, periprosthetic joint infection and implant-associated osteomyelitis of long bones is presented.

Management of the extensive thoracic defects after deep sternal wound infection with the rectus abdominis myocutaneous flap: A retrospective case series

Deep sternal wound infection is a severe complication after open heart surgery. According to the different severity and dimensions of the deep sternal wound infection, the treatment method is different. In this study, we aimed to describe our experience with the rectus abdominis myocutaneous flap for large sternal wound management, especially when 1 or 2 internal mammary arteries were absent.Between October 2010 and January 2016, a retrospective review of 9 patients who suffered from the extensive thoracic defects after deep sternal wound infection was conducted. All of these sternal defects encompassed almost the full length of the sternum after debridement. Defect reconstruction was achieved by covering with a rectus abdominis myocutaneous flap. When the ipsilateral or bilateral internal mammary artery had been harvested previously, we took advantage of the inferior epigastric artery to provide additional blood supply to the rectus abdominis myocutaneous flap. Thus, this flap had a double blood supply.There was no recurrent infection in all 9 patients. Three patients received the rectus abdominis myocutaneous flap with a double blood supply. Flap complications occurred in 2 patients (22%). One patient who did not have the double blood supply flap suffered from necrosis on the distal part of the flap, which was then debrided and reconstructed with a split-skin graft. The other patient had a seroma at the abdomen donor site and was managed conservatively. None of the patients died during the hospital stay.This study suggests that the rectus abdominis myocutaneous flap may be a good choice to repair the entire length of sternal wound. When 1 or 2 internal mammary arteries have been harvested, the inferior epigastric artery can be anastomosed to the second intercostal artery or the internal mammary artery perforator to provide the rectus abdominis myocutaneous flap with a double blood supply.

Ten-year analyses of the German DRG data about negative pressure wound therapy

Exact data regarding the clinical role of negative pressure wound therapy (NPWT) for wound care in a specific country are not available. Thus, we analysed the use of NPWT in hospitalised patients in Germany. Detailed lists of all hospitalised cases treated with NPWT in Germany for each of the years from 2005 to 2014 were obtained from the Federal Statistical Office, as well as lists of the 15 most frequent principal and additional diagnoses documented with NPWT in 2014. Within the 10-year time period of the study, the number of cases treated with NPWT increased by 349%, from 37 053 in 2005 to 129 269 in 2014. The rate of all hospitalised cases treated with NPWT increased form 0·22% to 0·66% in Germany. In 2014, wounds affecting skin and subcutaneous tissue (5-916.a0) are the most frequent documented indication for NPWT followed by deep wounds involving bones and joints at the limbs (5-916.a1). Open abdomens (5-916.a3) count for higher numbers than deep wounds of the thorax, mediastinum and sternum (5-916.a2). Fifty percent of all cases hospitalised for stage IV pressure ulcers at sacrum or ischium and around one third (32.2%) of cases with pyothorax received NPWT. Every fourth to fifth case hospitalised for disruption of surgical wounds or infections following a procedure (24·1%), as well as for infections and inflammations because of internal joint prosthesis or because of an internal fixation device was treated with NPWT (22·9%). In cases with diabetic foot syndrome, it is still every tenth case (10·1%). This analysis shows a substantial increase in the use of NPWT in the last decade for hospitalised patients. NPWT has a fixed role in the treatment of stage IV pressure ulcers at sacrum or ischium, pyothorax, infection and inflammation because of internal joint prosthesis or an internal fixation device and diabetic foot syndrome.