Mediastinitis after coronary artery bypass graft surgery. Risk factors and long-term survival

Confirmation of Safety of Titanium Wire in Sternotomy Closure, A Randomized Prospective Study

BACKGROUND

There are many factors that are known to increase the risk of sternal wound infection (SWI); some studies have reported that nickel is a risk factor for SWI. Titanium wires have only been used as an alternative to steel wires in patients with known allergy to nickel. However, there is a paucity of literature regarding the safety of using titanium wires compared to that on the safety of steel wires for sternum closure after cardiac surgery. Therefore, this study aimed to demonstrate the noninferiority of titanium wires, even in patients without a known allergy.

METHODS

A total of 322 patients who underwent elective full median sternotomy were randomly assigned to sternal closure either by titanium wires (n = 161) or by stainless steel wires.

RESULTS

Fourteen patients had sternal instability, six (3.7%) patients in the titanium group and eight (5%) patients in the stainless steel group (p = 0.585). There was no statistically significant difference between both groups in terms of postoperative wound infection (p = 0.147). Patients in the titanium group experienced statistically significant lower postoperative pain than those in the stainless steel group (p = 0.024). The wire type was not an independent risk factor for SI, as shown by univariate and logistic regression analyses.

CONCLUSION

Titanium wires are a good alternative and have been proven to be safe and effective for sternal closure. The surgeon should be aware of the possibility of developing an allergic reaction to the wires, especially in patients with previous multiple allergic histories.

Strategies to Minimize Sternal and Leg Wound Complications after Coronary Artery Bypass Grafting Using No-Touch Saphenous Vein Grafts

PURPOSE

The aims of the present study were to examine sternal and saphenous vein (SV) harvest site wound complication rates, and to assess the strategies to minimize the sternal and leg wound complications after coronary artery bypass grafting using a no-touch (NT) SV.

METHODS

Patients who underwent coronary artery bypass grafting (CABG) using internal thoracic artery (ITA) and/or NT SV grafts from March 2021 to June 2023 (N = 166) at a newly opened cardiac surgical program were included. We obeyed the current guidelines for the prevention of sternal wound infection. In addition, unilateral ITA was used in most of the patients and the sternal wound was meticulously closed using multiple sternal wires (≥7) and ZipFix. For the NT SV harvesting, the LigaSure device was used to minimize thermal injury, and the wound was meticulously closed.

RESULTS

Sternal wound infections developed in 3/166 (1.8%) patients; all three patients showed superficial sternal wound infections. Leg wound complications were present in 2/153 (1.3%) patients, who recovered after secondary intention healing.

CONCLUSION

Sternal wound complications after CABG could be minimized by the unilateral ITA usage, meticulous closure of the sternal wound in addition to compliance with the current guidelines. Wound complications after NT SV harvest may also be minimized by preoperative evaluation, careful harvesting, and meticulous wound closure.

Case Report of Complex Chest Wall Repair for Sternal Dehiscence After Bilateral Lung Transplantation

BACKGROUND

We report a case of a complex chest wall reconstruction because of sternal dehiscence, requiring different surgical procedures for its complete resolution.

CASE REPORT

A 54-year-old man patient with Langerhans cell histiocytosis and chronic obstructive pulmonary disease underwent bilateral sequential lung transplantation through a clamshell incision, using nitinol thermo-reactive clips for sternal closure. One year later, he consulted because of chest pain, fever, and purulent secretions. Physical examination and chest X-ray revealed a right pulmonary hernia due to post-clamshell wound dehiscence. Chest wall repair was performed, placing an expanded-polytetrafluoroethylene synthetic mesh, and the sternum was realigned and fixated with titanium plates and screws. However, in the immediate postoperative period, there was a large amount of serous drainage through the surgical wound, needing negative pressure therapy. Unfortunately, the wound became necrotic with exposure to the osteosynthesis material. In addition, a chest computed tomography scan showed fluid accumulation in the anterior chest wall. Therefore, two-stage revision surgery was indicated: first, the removal of the previous prosthesis and, the definite one, the use of a pedicled latissimus dorsi myocutaneous flap to provide effective coverage of the wound.

CONCLUSION

Sternal dehiscence is not an uncommon complication after clamshell incision in patients undergoing bilateral sequential lung transplantation, and it is associated with significant morbidity. In the presence of chest wall instability, surgical repair is mandatory.

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.

Troponin T and N-Terminal Pro-Brain Natriuretic Peptide Are Associated with Long-Term All-Cause Mortality in Patients with Post-Sternotomy Mediastinitis following Coronary Artery Bypass Grafting: A 15-Year Follow-Up Study

BACKGROUND

Deep sternal wound/mediastinitis is a rare but feared complication in coronary artery bypass grafting (CABG) patients and seems to increase the risk of cardiac death, and is also associated with the risk of early internal mammary artery (IMA) graft obstruction. The pathological mechanism explaining the link between mediastinitis and IMA graft obstruction and the impact on mortality is complex, multifactorial, and not fully investigated.

OBJECTIVES

Mediastinitis has been associated with increased concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) and troponin T (TnT) at mid-term follow-up, representing persistent low-grade myocardial injury and impaired cardiac function. However, whether mediastinitis is associated with all-cause mortality, or whether the association is driven by these cardiac-specific biomarkers (NT-proBNP and TnT), is not investigated.

METHODS

The present study provides the longest and most complete follow-up data in 82 patients undergoing CABG, including 41 with post-sternotomy mediastinitis.

RESULTS

The annualized incidence rate of mediastinitis was 0.14%/year and remained stable at 0.14% throughout the study period. During a mean follow-up of 12.7 ± 3.5 years, a total of 42 deaths occurred (27 [65.9%] in mediastinitis and 15 [36.6%] in non-mediastinitis group, p = 0.008). No association was found between IMA or saphenous vein graft obstruction with all-cause mortality. Mediastinitis was associated with a 1.9-fold increased risk of all-cause mortality. However, in the multivariable-adjusted models, age and higher TnT and NT-proBNP levels, but not mediastinitis per se were associated with all-cause mortality.

CONCLUSIONS

Mediastinitis after CABG surgery was associated with a poor prognosis during a 15-year follow-up, showing a nearly two-fold higher frequency of all-cause mortality compared with non-mediastinitis group, with the differences in mortality rate occurring primarily after 10 years. The association between mediastinitis and all-cause mortality was modulated by subclinical myocardial damage and stretch, reflected by elevated TnT and NT-proBNP, measured at 2.7-year follow-up, underscoring that these could represent prognostic markers in CABG patients.

Factors associated with deep sternal wound infection after open-heart surgery in a Danish registry

Objective

To conduct a comprehensive multivariate analysis of variables associated with deep sternal wound infection, after open-heart surgery via median sternotomy.

Method

A retrospective cohort of all adult patients, who underwent open-heart surgery at Odense University Hospital between 01-01-2000 and 31-12-2020 was extracted from the West Danish Heart Registry. Data were analyzed using maximum likelihood logistic regression.

Results

A total of 15,424 patients underwent open-heart surgery and 244 developed a deep sternal wound infection, equivalent to 1,58 %. After data review 11,182 entries were included in the final analysis, of which 189 developed DSWI, equivalent to 1,69 %. Multivariate analysis found the following variables to be associated with the development of deep sternal wound infection (odds ratios and 95%confidens intervals in parentheses): Known arrhythmia (1.70; 1.16-2.44), Left Ventricular Ejection Fraction (1.66; 1.02-2.58), Body Mass Index 25-30 (1.66; 1.12-2.52), Body Mass Index 30-35 (2.35; 1.50-3.71), Body Mass Index 35-40 (3.61; 2.01-6.33), Body Mass Index 40+ (3.70; 1.03-10.20), Age 60-69 (1.64; 1.04-2.67), Age 70-79 (1.95; 1.23-3.19), Chronic Obstructive Pulmonary Disease (1.77; 1.21-2.54), Reoperation (1.63; 1.06-2.45), Blood transfusion in surgery (1.09; 1.01-1.17), Blood transfusion in intensive care unit (1.03; 1.01-1.06), Known peripheral atherosclerosis (1.82; 1.25-2.61), Current smoking (1.69; 1.20-2.35), Duration of intubation (1.33; 1.12-1.57).

Conclusion

Increased risk of deep sternal wound infection after open-heart surgery is a multifactorial problem, while some variables are unchangeable others are not. Focus should be on optimizing the condition of the patient prior to surgery e.g. weight loss and smoking. But also factors surrounding the patient e.g. preventing blood loss and minimizing intubation time.

Consequences of Obesity on Short-Term Outcomes in Patients Who Underwent Off-Pump Coronary Artery Bypass Grafting Surgery

The correlation between off-pump coronary artery bypass (OPCAB) surgery and obesity-related outcomes is still uncertain. The aim of our study was to analyse the pre-, intra-, and postoperative short-term outcomes between obese and non-obese patients after off-pump bypass surgery. We performed a retrospective analysis from January 2017 until November 2022, including a total of 332 (non-obese (n = 193) and obese (n = 139)) patients who underwent an OPCAB procedure due to coronary artery disease (CAD). The primary outcome was all-cause in-hospital mortality. Our results showed no difference regarding mean age of the study population between both groups. The use of the T-graft technique was significantly higher (p = 0.045) in the non-obese group compared to the obese group. The dialysis rate was significantly lower in non-obese patients (p = 0.019). In contrast, the wound infection rate was significantly higher (p = 0.014) in the non-obese group compared to the obese group. The all-cause in-hospital mortality rate did not differ significantly (p = 0.651) between the two groups. Furthermore, ST-elevation myocardial infarction (STEMI) and reoperation were relevant predictors for in-hospital mortality. Therefore, OPCAB surgery remains a safe procedure even in obese patients.

Increased levels of NT-proBNP and troponin T 2 years after coronary artery bypass grafting complicated by mediastinitis

Background

Mediastinitis after coronary bypass grafting (CABG) increases the risk of the internal mammary artery (IMA) graft obstruction, and has a detrimental effect on long-term survival. The pathogenesis for this increased mortality is poorly understood. In the present study, we aimed to investigate the relationship between mediastinitis and persistently elevated cardiac-specific biomarkers [troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP)] and C-reactive protein (CRP) at mid-term follow-up following CABG.

Material and methods

The epidemiologic design was of an exposed (mediastinitis, n = 41) vs. randomly selected non-exposed (non-mediastinitis) controls (n = 41) cohort. Serum samples for measurements of NT-proBNP, TnT, and CRP were obtained at a median follow up time of 2.7 (range 0.5-5.2) years after CABG surgery.

Results

NT-proBNP (mean 65.0 pg/ml vs. 34.8 pg/ml, p = 0.007) and TnT levels (mean 14.7 ng/L vs. 11.2 ng/L, p = 0.004) were significantly higher in the mediastinitis group than in the control group. Patients with mediastinitis had also higher body mass index (BMI) and were more likely to have diabetes and previous myocardial infarction. There was no difference in serum CRP level between the groups. After controlling for potential confounders (previous myocardial infarction, age, and BMI), the presence of mediastinitis was associated with higher levels of log NT-proBNP (p = 0.02) and log TnT (p = 0.04).

Conclusion

Mediastinitis increases the concentrations of cardiac-specific biomarkers NT-proBNP and TnT at mid-term follow-up, representing persistent myocardial injury and impaired cardiac function.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sex-Associated Differences in Short-Term Outcomes in Patients with Deep Sternal Wound Infection after Open-Heart Surgery

Deep sternal wound infection (DSWI) is a feared complication after cardiac surgery. The impact of sex-related differences on wound infection prevalence is poorly understood. Our aim was to evaluate the effect of sex on short-term outcomes in patients with DSWI after open-heart surgery. The study was a retrospective cohort study. A total of 217 patients with DSWI were identified and retrospectively analyzed using our institutional database. Patients were divided into two groups: males (n = 150) and females (n = 67). This study also includes a propensity score based matching (PSM) analysis (male group (n = 62) and female group (n = 62)) to examine the unequal groups. Mean age (p = 0.088) and mean body mass index (BMI) (p = 0.905) did not significantly differ between both groups. Vacuum assisted closure (VAC) therapy was performed among most patients (82.3% (male group) vs. 83.9% (female group), p = 0.432). The most commonly isolated bacteria from the wounds were Staphylococcus epidermidis and Staphylococcus aureus in both groups. Acute renal failure was significantly higher (p = 0.010) in the male group compared to the female group. However, dialysis rate did not significantly differ (p = 0.491) between male and female groups. Further secondary outcomes showed no major differences between the groups. Likewise, in-hospital mortality rate did not differ significantly (p = 0.680) between both groups. Based on our data, sex has no impact on deep wound infection prevalence after cardiac surgery.

Co-Management Reduces Mortality in Post-Sternotomy Mediastinitis

Background: Post-sternotomy mediastinitis (PSM) is one of the most feared complications of cardiac surgery. The impact of a multidisciplinary management approach on this pathology is yet unknown. Patients and Methods: A multidisciplinary approach based on a co-management model (CMM) of care was initiated in January 2018 because of the incorporation of a hospitalist unit on a cardiac surgery department. An observational retrospective cohort study was designed to evaluate the impact of the CMM of care compared to the standard model (SM) of care in patients diagnosed with PSM. Our primary and secondary outcomes were survival time and treatment failure rate (two or more surgical procedures needed to solve PSM or PSM-related death), respectively. Data related to patient death date were collected from the Spanish National Death Index. A multivariable Cox regression model was created using those variables believed to be clinically relevant. Results: Ninety-one patients developed PSM from January 2010 to June 2020. Regarding the pre-operative clinical status, surgical procedure, and PSM severity, both groups had similar baseline characteristics. Patients were followed for a mean of 27.54 ± 30.5 months. A total of 60.3% of the SM group and 11.1% of the CMM group (p < 0.001) died. Treatment failure occurred in 53 patients (72.6%) in the SM group versus 7 (38.6%) in the CMM group (p = 0.007). The CMM independently reduced overall mortality (hazard ratio [HR], 0.11; 95% confidence interval [CI]. 0.01-0.83) and treatment failure rate (HR, 0.01; 95% CI, 0.001-0.183). Gram-positive bacterial infection (HR, 3.73; 95% CI, .6-8.3), and complete osteosynthesis material removal (HR, 0.47; 95% CI, 0.24-0.91) also influenced mortality in our model. Conclusions: A co-management care model reduced overall mortality in patients diagnosed with post-sternotomy mediastinitis.

Evaluating the effectiveness of using negative pressure wound therapy in the preservation of the infected prosthetic aortic graft

BACKGROUND

Infected deep sternal infection due to an associated infection of the prosthetic aortic graft is a devastating condition. Standard management requires the removal of the graft and substituting it with a new one. Often, removal of the prosthetic graft is close to impossible. Negative pressure wound therapy is currently the treatment of choice for patients with deep sternal infection. However, its use in deep sternal infection with exposed infected prosthetic aortic graft has not been well described.

METHODS

Eight patients were included in this study. All had type A aortic dissection of the ascending aorta and/or aortic arch.

RESULTS

There were 7 men and 1 woman. The median age was 53 years old (range 33-81 years old). The median number of days from the initial aortic operation to the diagnosis of infection was 20 days (range 14-52). The median length of stay in the intensive care unit was 17 days (range 6-338 days). The median time interval from the initial debridement to reconstruction was 20 days (range 6-43 days). The median number of times negative pressure wound therapy was changed was 4 (range 2-9). The most common flap used for reconstruction was the pectoralis major musculocutaneous flap in 7 patients, a free antero-lateral thigh flap in 1 patient, and pedicled omental flap in combination with pectoralis major musculocutaneous flap in 1 patient. One patient had persistent recurrent infection of the graft despite negative pressure wound therapy and flap reconstruction. The median length of follow-up was 38.5 months (range 4-120 months).

CONCLUSION

This small study suggests that negative pressure wound therapy could be used successfully for the management of deep sternal infection due to infected prosthetic aortic grafts. In most cases, it eliminated the need to replace the infected prosthetic aortic graft in high-risk patients.

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.

Current Management of Sternal Wounds

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Describe the pathogenesis, classification, and risk factors of sternal wound infection. 2. Discuss options for sternal stabilization for the prevention of sternal wound infection, including wiring and plating techniques. 3. Discuss primary surgical reconstructive options for deep sternal wound infection and the use of adjunctive methods, such as negative-pressure wound therapy.

SUMMARY

Poststernotomy sternal wound infection remains a life-threatening complication of open cardiac surgery. Successful treatment relies on timely diagnosis and initiation of multidisciplinary, multimodal therapy.

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.

Short- and long-term mortality after deep sternal wound infection following cardiac surgery: experiences from SWEDEHEART

OBJECTIVES

Deep sternal wound infection (DSWI) is a serious complication after open-heart surgery. We investigated the association between DSWI and short- and long-term all-cause mortality in a large well-defined nationwide population.

METHODS

A retrospective, nationwide cohort study, which included 114676 consecutive patients who underwent coronary artery bypass grafting (CABG) and/or valve surgery from 1997 to 2015 in Sweden. Short- and long-term mortality was compared between DSWI patients and non-DSWI patients using propensity score inverse probability weighting adjustment based on patient characteristics and comorbidities. Median follow-up was 8.0 years (range 0-18.9).

RESULTS

Altogether, 1516 patients (1.3%) developed DSWI, most commonly in patients undergoing combined CABG and valve surgery (2.1%). DSWI patients were older and had more disease burden than non-DSWI patients. The unadjusted cumulative mortality was higher in the DSWI group compared with the non-DSWI group at 90 days (7.9% vs 3.0%, P < 0.001) and at 1 year (12.8% vs 4.5%, P < 0.001). The adjusted absolute difference in risk of death was 2.3% [95% confidence interval (CI): 0.8-3.9] at 90 days and 4.7% (95% CI: 2.6-6.7) at 1 year. DSWI was independently associated with 90-day [adjusted relative risk (aRR) 1.89 (95% CI: 1.38-2.59)], 1-year [aRR 2.13 (95% CI: 1.68-2.71)] and long-term all-cause mortality [adjusted hazard ratio 1.56 (95% CI: 1.30-1.88)].

CONCLUSIONS

Both short- and long-term mortality risks are higher in DSWI patients compared to non-DSWI patients. These results stress the importance of preventing these infections and careful postoperative monitoring of DSWI patients.

Early to midterm survival of patients with deep sternal wound infection managed with laparoscopically harvested omentum

OBJECTIVE

The optimal management of deep sternal wound infection (DWSI) remains controversial. Our objective was to evaluate outcomes of patients with DSWI managed with transposition of laparoscopically harvested omentum (LHO).

METHODS

Between 2000 and 2020, a total of 38,623 adult patients who underwent full median sternotomy for cardiac surgery were analyzed retrospectively at our institution. DSWI occurred in 455 (1.2%), of whom 364 (93.2%) were managed with pectoralis myocutaneous flap (PMF) and 33 (7.2%) with LHO. Univariate and multivariate analysis models were used to determine predictors of cumulative late mortality and adjusted survival curves were generated.

RESULTS

Among patients who received LHO, average age was 65.7 ± 9.7 years and a larger proportion of patients were male. A majority of patients (88%) had coronary bypass surgery, with bilateral internal mammary arteries use in only 21.2%. Mean length of stay (LOS) was 58.90 days and early hospital mortality occurred in 4 patients (12.1%). Patients who received LHO compared to only PMF had larger body mass index and had more heart failure. Furthermore, the hospital LOS was also significantly prolonged in the LHO group (58.9 vs. 27.4 days, p = .002), with a slightly higher in-hospital mortality (12.1% vs. 3.3%, p = .03). Late survival for LHO patients at 5 and 10 years was 71.9% and 44.8%, respectively.

CONCLUSION

Use of LHO is a safe and viable alternative to traditional myocutaneous flaps to manage complex DSWI. Early and late survival were favorable in this high-risk population.

Pancreatic enzymatic mediastinitis followed by total gastrectomy with splenectomy: report of two cases

BACKGROUND

Acute mediastinitis is a rare disease that rapidly progresses with a high mortality rate. Its most common cause is direct injury of the mediastinum, including iatrogenic causes such as cardiac surgery or upper endoscopy. Enzymatic mediastinitis is a rare complication of a pancreatic fistula caused by the inflammatory digestion of the parietal peritoneum spreading to the mediastinum. Here, we present two cases of enzymatic mediastinitis caused by total gastrectomy with splenectomy. One of them was successfully treated and cured after early diagnosis and transabdominal drainage.

CASE PRESENTATION

Case 1 was that of a 60-year-old man (body mass index [BMI] 27) with a medical history of diabetes and hypertension who was diagnosed with advanced gastric cancer in the upper body of the stomach. A total gastrectomy with splenectomy was performed. The patient experienced acute respiratory failure 24 h after surgery. Pulmonary embolism was suspected, so a computed tomography (CT) scan was performed; however, no relevant causes were found. Although he was immediately intubated and treated with catecholamine, he died in the intensive care unit (ICU) 40 h after surgery. Post-mortem findings revealed retroperitonitis caused by a pancreatic fistula spreading towards the mediastinum, causing severe mediastinitis; a review of the CT scan revealed pneumomediastinum. We concluded that the cause of death was enzymatic mediastinitis due to post-gastrectomy pancreatic fistula. Case 2 involved a 61-year-old man (BMI 25) with a medical history of appendicitis who was diagnosed with advanced gastric cancer at the gastric angle between the lesser curvature and the pylorus, spreading to the upper body of the stomach. A total gastrectomy with splenectomy was also performed. The patient had a high fever 3 days after the surgery, and a CT scan revealed pneumomediastinum, indicating mediastinitis. As the inflammation was below the bronchial bifurcation, we chose a transabdominal approach for drainage. The patient was successfully treated and discharged.

CONCLUSION

Acute mediastinitis caused by gastrectomy is rare. The acknowledgment of abdominal surgery as a cause of mediastinitis is important. In treating mediastinitis caused by abdominal surgery, transabdominal drainage may be a minimally invasive yet effective method if the inflammation is mainly located below the bifurcation of the trachea.

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.

Sternal wound infections during the COVID-19 pandemic: an unexpected benefit

BACKGROUND

The novel coronavirus, now termed SARS-CoV-2, has had a significant impact on cardiac surgical services globally. Although drastically reduced, our institution has maintained a significant level of cardiac surgical activity during the pandemic. Rigorous COVID-19 guidelines have been instituted to mitigate the risk of viral transmission. We observed a reduction in sternal wound infections since the institution of new perioperative surgical guidelines.

METHODS

We performed a retrospective analysis of all patients who underwent cardiac surgery at our institution since a national lockdown was declared in March 2020. A retrospective analysis of all patients who underwent cardiac surgery in the 12 months preceding the national lockdown, as a baseline cohort group, was also performed.

RESULTS

A total of 2600 patients (493 during the COVID-19 pandemic) were included in this study. Urgent/emergency procedures accounted for more than 60% of procedures performed during the lockdown compared to 39% previously. During the COVID-19 pandemic, there were 4 sternal wound infections with an overall incidence of 0.8%. In comparison, the incidence of sternal wound infections was significantly higher at 3.0% in the 12-month period prior to lockdown with 63 sternal wound infections (p = 0.006).

CONCLUSION

This report suggests a significant role of iatrogenic causes in sternal wound infections prior to the pandemic. The strict implementation of guidelines in the perioperative period suggests that sternal wound infections can be prevented. We propose that the now widespread COVID-19 guidelines to reduce transmission risk be adapted to help reduce the incidence of sternal wound infections.

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.

Emerging trends in mediastinitis: National Veterans Health Administration experience with methicillin-resistant Staphylococcus aureus prevention

OBJECTIVES

Perioperative bacterial decolonization and prophylactic antibiotic therapy at the Veterans Affairs Health Care System have changed over the past decade. Our objectives were to identify associated changes in the microbiology of mediastinitis and to perform a contemporary survival analysis in patients with mediastinitis after isolated coronary artery bypass grafting procedure.

METHODS

From January 2006 to December 2015, 45,323 consecutive patients underwent coronary artery bypass grafting at 83 medical centers. The Veterans Affairs Health Care System nationwide administrative database was queried to identify patients with postoperative mediastinitis and obtain patient-level data. Simple descriptive statistics and multivariable logistic regression were used to analyze microbiologic data and identify risk factors for infection. Poisson regression was used to determine yearly incidence estimates. Cox proportional hazard model identified predictors of long-term survival from date of operation.

RESULTS

During the study period, 348 patients (0.78%) developed postoperative mediastinitis-with a stable rate of incidence (Cochrane-Armitage test, P = .69). Of patients with microbiologic data, 75.5% of infections (n = 188) were caused by gram-positive and 24.5% (n = 61) gram-negative organisms. The incidence of methicillin-resistant Staphylococcus aureus mediastinitis decreased during the study period (Cochrane-Armitage test, P = .013). Gram-negative mediastinitis occurred earlier than gram-positive mediastinitis (median, 15.0 vs 25.0 days; P < .0001). Patients with mediastinitis did not have increased 30-day mortality (2.0% vs 1.9%; P = .9), but had worse long-term survival compared with uninfected patients (P < .0001).

CONCLUSIONS

The incidence of methicillin-resistant S aureus mediastinitis has decreased over the past decade. Gram-negative bacteria are responsible for 1 in 4 cases of mediastinitis and infection is diagnosed earlier in the postoperative period than gram-positive mediastinitis. These findings highlight the need for efforts to prevent gram-negative and methicillin-susceptible S aureus mediastinitis.

Does using Jackson-Pratt drain affect the incidence of sternal wound complications after open cardiac surgery?

Background

TThis study aims to investigate the effect of the Jackson-Pratt drain on sternal wound complications in patients with a Body Mass Index of ≥30 kg/m² undergoing open cardiac surgery via median sternotomy.

Methods

A total of 174 patients (124 males, 50 females; mean age 58.2±10.4 years; range, 33 to 78 years) with a Body Mass Index of ≥30 kg/m² undergoing cardiac surgery via median sternotomy between January 2011 and December 2015 in our institution were retrospectively analyzed. Of the patients, 94 were inserted a Jackson-Pratt drain (JP group) following median sternotomy, while 80 patients received no drain (non-JP group). Pre-, intra, and postoperative outcomes of both groups including type of operation, length of hospital stay, and complications were compared.

Results

No significant difference in the age, gender, Body Mass Index, and potential risk factors was found between the groups. The median of stay in the intensive care unit was two days and the median time from operation to discharge was seven days in both groups. There was a statistically significant difference in the rate of sternal wound complications between the groups. Sternal wound complications occurred in two patients (2.1%) in the drained group, compared to nine patients (11.25%) in the non-drained group (p=0.01).

Conclusion

Our study results show that Jackson-Pratt drain insertion after median sternotomy in patients with a Body Mass Index of ≥30 kg/m² undergoing open cardiac surgery is a simple and reliable method to reduce the risk of postoperative sternal wound complications, compared to the conventional closure technique.

Deep sternal wound infection - latissimus dorsi flap is a reliable option for reconstruction of the thoracic wall

Background

At present, data describing patients’ long-term outcomes, quality of life, and survival after deep sternal wound infection are rarely available.

The purpose of our study was to evaluate functional outcome and patient well-being after debridement and reconstruction of the sternal defect using a pedicled latissimus dorsi flap following deep sternal wound infection (DSWI).

Methods

This retrospective analysis reviewed 106 cases of DSWI after open-heart surgery treated between May 1, 2012, and May 31, 2015. The parameters of interest were demographic and medical data, including comorbidity and mortality. Follow-up consisted of physical examination of the patients using a specific shoulder assessment, including strength tests and measurements of pulmonary function.

Results

The population consisted of 69 (65%) male and 37 (35%) female patients. Their average age at the time of plastic surgery was 69 years (range: 35–85). The 30-day mortality was 20% (n = 21); after one-year, mortality was 47% (n = 50), and at follow-up, it was 54% (n = 58).

Heart surgery was elective in 45 cases (42%), urgent in 31 cases (29%) and for emergency reasons in 30 cases (28%). The preoperative European System for Cardiac Operative Risk Evaluation (EuroSCORE) averaged 16.3 (range: 0.88–76.76).

On the dynamometer assessment, a value of 181 Newton (N) (±97) could be achieved on the donor side, in contrast to 205 N (±91) on the contralateral side.

The inspiratory vital capacity of the lung was reduced to an average of 70.58% (range: 26–118), and the forced expiratory volume in 1 s was decreased to an average of 69.85% (range: 38.2–118).

Conclusions

Given that only small adverse effects in shoulder function, strength, and pulmonary function were observed, the latissimus dorsi flap appears to be a safe and reliable option for the reconstruction of the sternal region after DSWI.

Mediastinitis in open heart surgery: a systematic review and meta-analysis of risk factors

Objective. We aimed to summarize the evidence from observational studies examining the risk factors of the incidence of mediastinitis in open heart surgery. Design. The study was a systematic review and meta-analysis of cohorts and case-control studies. Material and methods. We searched the literature and 74 studies with at least one risk factor were identified. Both fixed and random effects models were used. Heterogeneity between studies was examined by subgroup and meta-regression analysis. Publication bias or small study effects were evaluated and corrected by limit meta-analysis. Results. When correcting for small study effect, presence of obesity as estimated from 43 studies had Odds Ratio OR = 2.26. (95% CI: 2.17-2.36). This risk was increasing with decreasing latitude of study place. Presence of diabetes mellitus from 63 studies carried an OR = 1.90 (95% CI: 1.59-2.27). Presence of Chronic Obstructive Pulmonary Disease (COPD) from 30 studies had an OR = 2.59 (95% CI: 2.22-2.85). Presence of bilateral intramammary graft (BIMA) from 23 studies carried an OR = 2.54 (95% CI: 2.07-3.13). This risk was increasing with increasing frequency of female patients in the study population. Conclusion. Evidence from this study showed the robustness of the risk factors in the pathogenesis of mediastinitis. Preventive measures can be implemented for reducing obesity, especially in lower latitude countries. Furthermore, it is mandatory to monitor perioperative hyperglycemias with continuous insulin infusion. Use of skeletonized BIMA carries higher risk of mediastinitis especially in female patients without evidence of beneficial effect on survival for the time being.

Efficacy of new multimodal preventive measures for post-operative deep sternal wound infection

BACKGROUND

Deep sternal wound infection (DSWI) is a critical complication of cardiovascular surgery. This study aimed to confirm the efficacy of new, multimodal preventive measures for post-operative DSWI.

METHODS

From January 2008 to December 2012, 1240 patients underwent cardiovascular surgery via median sternotomy at our hospital. The patients were divided into two groups according to the period in which surgery was performed: those treated before and those treated after January 2011, which was when we implemented the new preventive measures against DSWI. The preventive measures included routine use of an off-pump technique in coronary artery bypass grafting, higher body temperature of pump cases, screening and pre-operative eradication of nasal methicillin-resistant Staphylococcus aureus colonization, and use of a microbial sealant. We compared the incidence of DSWI between the two time periods. Univariate and multivariate analyses were also performed for the entire period to identify DSWI risk factors.

RESULTS

Only 1 case (0.2%) of DSWI was noted among 554 patients in the latter period while 25 patients (3.6%) experienced DSWI among the 686 patients in the earlier period (p < 0.0001). The risk factors for DSWI were body mass index (BMI) ≥ 25 kg/m² and operation time ≥ 8 h.

CONCLUSIONS

We observed a marked decrease in the incidence of DSWI after the implementation of multimodal preventive measures. The risk factors for DSWI were BMI ≥ 25 kg/m² and operation time ≥ 8 h.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Concordance between superficial swab and deep sampling in post-sternotomy mediastinitis: Single center experience

OBJECTIVES

Deep sampling (DS) is the gold standard for microbiological diagnosis of post-sternotomy mediastinitis (PSM), however superficial swab (SS) are frequently performed in some centers and antibiotherapy initiated base on their results. We analysed the concordance between superficial swab and deep sampling in PSM.

MATERIALS AND METHODS

We analysed retrospectively patients with a PSM between 2010 and 2014 at Saint-Luc University hospital (Belgium). We considered that there was a concordance between SS and DS when the same microorganism was found in the two sampling method in each patient. Patients were stratified in six groups according to microbiology results as Staphylococcus Aureus (SA) sensitive or resistant, coagulase negative Staphylococcus (CoNS), Gram negative bacilli (GNB), other Gram positive bacteria (GPB) and fungi.

RESULTS

Thirty-six patients were included. Twenty-five men (69%) and a mean age of 66 years old. The overall concordance between SS and DS was 57%. SA and GNB showed high concordance (100% and 85.7% respectively). For the other groups the concordance was low. The sensitivity and specificity of SS was 97% and 33% respectively. The PPV and NPV of superficial swab was 96% and 50% respectively.

CONCLUSION

Microbiological results from SS, even with flocked swabs, except for SA and GNB have low concordance with those obtained from deep sampling. Our data confirm that in PSM, deep sampling is the gold standard for microbiological assessment.

Platelet-leukocyte rich gel application in the prevention of deep sternal wound problems after cardiac surgery in obese diabetic patients

Background

Deep sternal wound problems (DSWP) are a rare, but serious complication following cardiac surgery requiring extensive medical treatment and resulting in increased mortality. Cardiac surgery patients presenting with both obesity and diabetes mellitus type 2 (DM 2) showed an increased incidence of DSWP in our clinic. As platelets upon activation have been shown to excrete growth factors and attractants for tissue stem cells, thus potentially promoting tissue healing, we investigated whether activated platelets could reduce the incidence of DSWP.

Methods

We applied activated autologous platelet rich plasma (PRP), forming a gel (PLG), between the sternal halves immediately prior to closure in obese [body mass index (BMI) >30] DM 2 cardiac surgery patients. The reference group constituted of all elective patients with a BMI >30 and DM 2 operated upon in the 2-year period before the application of PLG.

Results

The PLG treated group (n=144) showed a significant decrease in DSWP compared to the reference group (n=118), 6 DSWP vs. 13 DSWP respectively, P=0.03. In these groups the application of PLG was associated with a risk reduction for DSWP from 11% to 4.2%.

Conclusions

These results suggest PLG application could be beneficial to prevent DSWP following cardiac surgery in a high-risk population.

Nutritional Considerations of Cardiovascular Diseases and Treatments

Nutritional considerations of many chronic diseases are not fully understood or taken into consideration in everyday clinical practice. Therefore, it is not surprising that high proportion of hospitalized patients with cardiovascular diseases remains underdiagnosed with malnutrition. Malnourished patients have increased risk of poor clinical outcomes, complications rate, prolonged hospital stay, more frequent rehospitalizations, and lower quality of life. The purpose of this review is to recapitulate recent data on nutritional considerations in cardiovascular medicine.

A review of the AATS guidelines for the prevention and management of sternal wound infections

Purpose

To summarize the AATS guidelines for the prevention and treatment of sternal wound infections.

Methods

The current AATS guidelines for the prevention of sternal wound infections during the preoperative, intraoperative, and postoperative periods, and the most effective methods and techniques to treat sternal wound infections were reviewed.

Results

The guidelines identified multiple interventions that can be instituted during the preoperative, intraoperative, and postoperative periods to reduce sternal wound infections during cardiac surgery. These include the use of perioperative antibiotics, glycemic control to maintain serum glucose < 180 mg/dl, avoidance of bone wax and the use of vancomycin paste to the sternal edges, and figure of eight suture techniques to re-approximate the sternum. Wound Vac therapy should be instituted whenever possible to treat and enhance recovery from mediastinitis.

Conclusions

The prevention of sternal wound infections and mediastinitis can be achieved by adherence to the AATS guidelines. The institution of these interventions requires a multi-disciplinary team effort among surgeons, anesthesiologists, referring physicians, nurses, and OR and ICU personnel.

Deep sternal infections after in situ bilateral internal thoracic artery grafting for left ventricular myocardial revascularization: predictors and influence on 20-year outcomes

Background

The incidence and potential factors influencing deep sternal wound infection (DSWI) in a cohort of patients undergoing coronary artery bypass grafting (CABG) using skeletonized bilateral internal thoracic artery (BITA) was explored. Furthermore, we studied influence of DSWI on long-term survival, major adverse cardiac events (MACEs) and repeat coronary revascularization (RCR).

Methods

The study cohort consisted of 1,325 consecutive patients who were divided in two groups: patients experiencing DSWI (n=33, group 1) and those who did not have sternal infection (n=1,292, group 2). A logistic regression model was employed to find predictors of DSWI whereas Cox regression and a competing risk models were carried out to test predictors of late death, MACE and RCR, respectively. Follow up was 100% complete and ranged from 1 to 245 months. Median follow-up was 103 months (IQR, 61 to 189 months). Cumulative follow-up was 16,430 patient years.

Results

The incidence of DSWI was 2.4%. Multivariable logistic regression analysis found any single independent predictor of DSWI. However, the association of peripheral vascular disease (PVD) and diabetes increased the risk by 1.4 and 1.6 times. When DM was associated with obesity the risk increased by 2.1 and 2.6 times compared to the single factors, respectively. Obese female patients were at a 1.6-fold higher risk when compared to the association of DM with obesity. DSWI was not an independent predictor of long-term survival (HR, 2.31; 95% CI: 0.59-9.12), RCR (SHR, 2.89; 95% CI: 0.65-10.12), or MACE (SHR, 1.98; 95% CI: 0.44-8.56).

Conclusions

With an accurate patient selection (i.e., exclusion of obese diabetic females) and strict DM control BITA represents a first choice for most of CABG patients, even at high risk for DSWI. The occurrence of DSWI does not influence long-term survival and late outcomes. Our findings should be confirmed by further larger research.

Hyperbaric Oxygen Therapy in Treating a Poorly Healing Wound Following Cardiac Surgery in a Patient with Congenital Connective Tissue Defect – Case Report

We hereby present the case of a female patient with recurrent aortic aneurysms. In order to treat aneurysms of the ascending aorta, aortic arch and aneurysms of the aortic arch branches, the debranching procedure was used. Following the surgery, a deep sternal wound infection occurred characterised by impaired healing. The infection was treated with targeted antibiotic therapy and hyperbaric oxygen therapy.

The effect of obesity on long-term survival and health-related quality of life after coronary artery bypass grafting: a 12-year follow-up

OBJECTIVE

The proportion of obese patients undergoing coronary artery bypass graft (CABG) surgery is increasing. In this study, our main objective was to assess the effect of obesity on long-term mortality and changes in quality of life (QoL) after GABG.

MATERIALS AND METHODS

Data of 508 patients who underwent isolated GABG were prospectively collected. RAND-36 Health Survey (RAND-36) was used as an indicator of QoL. BMI was used to assess obesity, and the analysis was based primarily on two patient groups: BMI less than 30 kg/m (408 patients) and BMI of at least 30 (100 patients). All assessments were made preoperatively and repeated 1 and 12 years after CABG surgery. The follow-up of the cohort was complete in 95 and 84% of the alive patients at 1 and 12 years, respectively.

RESULTS

Thirty-day, 1-year, and 10-year survival rates were 99.0, 97.0, and 78.0%, respectively, in the obese and 98.0, 96.8, and 79.2%, respectively, in the nonobese group. Obese showed significant (P<0.05) improvements only in four and nonobese in seven of eight RAND-36 dimensions of QoL. In both obese and nonobese patients, improved RAND-36 physical component summary and mental component summary scores were seen in comparison with the preoperative values. Yet, obese patients had a more pronounced diminution in their physical component summary and mental component summary scores, whereas nonobese patients maintained their physical and mental health status better.

CONCLUSION

Despite an on-going decline in 12 years after the CABG, both patient groups showed improvements in their health status in comparison with preoperative values. Obese patients gained less benefit in terms of QoL dimension, but there was no significant difference in overall mortality in the long-term follow-up.

Development and Validation of a Stratification Tool for Predicting Risk of Deep Sternal Wound Infection after Coronary Artery Bypass Grafting at a Brazilian Hospital

Objective

Deep sternal wound infection following coronary artery bypass grafting is a serious complication associated with significant morbidity and mortality. Despite the substantial impact of deep sternal wound infection, there is a lack of specific risk stratification tools to predict this complication after coronary artery bypass grafting. This study was undertaken to develop a specific prognostic scoring system for the development of deep sternal wound infection that could risk-stratify patients undergoing coronary artery bypass grafting and be applied right after the surgical procedure.

Methods

Between March 2007 and August 2016, continuous, prospective surveillance data on deep sternal wound infection and a set of 27 variables of 1500 patients were collected. Using binary logistic regression analysis, we identified independent predictors of deep sternal wound infection. Initially we developed a predictive model in a subset of 500 patients. Dataset was expanded to other 1000 consecutive cases and a final model and risk score were derived. Calibration of the scores was performed using the Hosmer-Lemeshow test.

Results

The model had area under Receiver Operating Characteristic (ROC) curve of 0.729 (0.821 for preliminary dataset). Baseline risk score incorporated independent predictors of deep sternal wound infection: obesity (P=0.046; OR 2.58; 95% CI 1.11-6.68), diabetes (P=0.046; OR 2.61; 95% CI 1.12-6.63), smoking (P=0.008; OR 2.10; 95% CI 1.12-4.67), pedicled internal thoracic artery (P=0.012; OR 5.11; 95% CI 1.42-18.40), and on-pump coronary artery bypass grafting (P=0.042; OR 2.20; 95% CI 1.13-5.81). A risk stratification system was, then, developed.

Conclusion

This tool effectively predicts deep sternal wound infection risk at our center and may help with risk stratification in relation to public reporting and targeted prevention strategies in patients undergoing coronary artery bypass grafting.

Negative Pressure Wound Therapy on Closed Surgical Wounds With Dead Space: Animal Study Using a Swine Model

Background

Closed incisional wound surgery frequently leaves dead space under the repaired skin, which results in delayed healing. The purpose of this study was to evaluate the effect of negative pressure wound therapy (NPWT) on incisional wounds with dead space after primary closure by evaluating the fluid volume through the suction drain, blood flow of the skin, tensile strength, and histology of the wounds.

Methods

Bilateral 25-cm-long incisional wounds with dead space were created on the back of 6 pigs by partially removing the back muscle and then suturing the skin with nylon sutures. NPWT (experimental group) or gauze dressing (control group) was applied over the closed incision for 7 days. Analysis of the wound included monitoring the amount of closed suction drain, blood perfusion unit, tensile strength of the repaired skin, and histology of the incision site.

Results

The drainage amount was significantly reduced in the experimental group (49.8 mL) compared to the control group (86.2 mL) (P = 0.046). Skin perfusion was increased in the experimental group with statistical significance compared to the control group (P = 0.0175). Collagen staining was increased in the experimental group. The tensile strength of the incision site was significantly higher in the experimental group (24.6 N at 7 days, 61.67 N at 21 days) compared to the control group (18.26 N at 7 days, 50.05 N at 21 days) (P = 0.02).

Conclusion

This study explains some of the mechanism for using NPWT in closed incision wounds with dead space. It demonstrates that NPWT significantly reduces drainage amount, increases skin perfusion, increases tensile strength, and has the tendency to promote collagen synthesis for closed wound with dead space indicating enhanced healing.

European Association for Cardio-Thoracic Surgery expert consensus statement on the prevention and management of mediastinitis

Mediastinitis continues to be an important and life-threatening complication after median sternotomy despite advances in prevention and treatment strategies, with an incidence of 0.25-5%. It can also occur as extension of infection from adjacent structures such as the oesophagus, airways and lungs, or as descending necrotizing infection from the head and neck. In addition, there is a chronic form of 'chronic fibrosing mediastinitis' usually caused by granulomatous infections. In this expert consensus, the evidence for strategies for treatment and prevention of mediatinitis is reviewed in detail aiming at reducing the incidence and optimizing the management of this serious condition.

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.

Effects of Incisional Negative-Pressure Wound Therapy on Primary Closed Defects after Superficial Circumflex Iliac Artery Perforator Flap Harvest: Randomized Controlled Study

BACKGROUND

Prolonged hematoma or seroma after primary closure is a causative element in wound complications. This study evaluated the effects of negative-pressure wound therapy on primary closed wounds after superficial circumflex iliac artery perforator flap harvest.

METHODS

This study was a prospective, randomized, clinical trial comparing conventional dressing against a single application of negative-pressure wound therapy for 5 days after primary closure. A total of 100 patients who had superficial circumflex iliac artery perforator flap harvest were enrolled.

RESULTS

There was no statistical difference between the incisional negative-pressure wound therapy and conventional dressing groups in the distribution of risk factors. Significant findings were noted for duration and amount of closed suction drainage: 6.12 ± 4.99 days (median, 4 days; range, 3 to 8 days) and 100.47 ± 140.69 cc (median, 42 cc) for wounds treated with conventional dressing versus 3.34 ± 1.35 days (median, 3 days; range, 2 to 4 days) and 23.28 ±18.36 cc (median, 20 cc) for wounds in treatment group (p = 0.0077 and p = 0.0004), respectively. After closure, an increase in skin perfusion were noted on day 5 in the treatment group (p = 0.0223). There was one case of wound dehiscence in the conventional dressing group.

CONCLUSION

The incisional negative-pressure wound therapy has a positive effect over primary closed surgical defects by significantly reducing the amount of fluid collected by closed suction drains, allowing earlier removal of drains and enhancing the skin perfusion on the repaired skin.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Adjunctive Hyperbaric Oxygen Therapy or Alone Antibiotherapy? Methicillin Resistant Staphylococcus aureus Mediastinitis in a Rat Model

OBJECTIVE

In the post-sternotomy mediastinitis patients, Staphylococcus aureus is the pathogenic microorganism encountered most often. In our study, we aimed to determine the efficacy of antibiotic treatment with vancomycin and tigecycline, alone or in combination with hyperbaric oxygen treatment, on bacterial elimination in experimental S. aureus mediastinitis.

METHODS

Forty-nine adult female Wistar rats were used. They were randomly divided into seven groups, as follows: non-contaminated, contaminated control, vancomycin, tigecycline, hyperbaric oxygen, hyperbaric oxygen + vancomycin and hyperbaric oxygen + tigecycline. The vancomycin rat group received 10 mg/kg/day of vancomycin twice a day through intramuscular injection. The tigecycline group rats received 7 mg/kg/day of tigecycline twice a day through intraperitoneal injection. The hyperbaric oxygen group underwent 90 min sessions of 100% oxygen at 2.5 atm pressure. Treatment continued for 7 days. Twelve hours after the end of treatment, tissue samples were obtained from the upper part of the sternum for bacterial count assessment.

RESULTS

When the quantitative bacterial counts of the untreated contaminated group were compared with those of the treated groups, a significant decrease was observed. However, comparing the antibiotic groups with the same antibiotic combined with hyperbaric oxygen, there was a significant reduction in microorganisms identified (P<0.05). Comparing hyperbaric oxygen used alone with the vancomycin and tigecycline groups, it was seen that the effect was not significant (P<0.05).

CONCLUSION

We believe that the combination of hyperbaric oxygen with antibiotics had a significant effect on mediastinitis resulting from methicillin-resistant Staphylococcus aureus. Methicillin-resistant Staphylococcus aureus mediastinitis can be treated without requiring a multidrug combination, thereby reducing the medication dose and concomitantly decreasing the side effects.

Hyperbaric oxygen therapy as additional treatment in deep sternal wound infections - a single center's experience

INTRODUCTION

Deep sternal wound infection (DSWI) is one of the most serious complications after cardiac surgery procedures, observed in 5% of patients. Current standard medical therapy for DSWI includes antibiotics, surgical debridement, resuturing or negative pressure wound therapy (NPWT). Unfortunately, in some cases these methods are insufficient, and additional therapeutic options are needed.

AIM

To assess the effects and usefulness of additional hyperbaric oxygen therapy (HBO2) in patients with DSWI after cardiac surgery procedures.

MATERIAL AND METHODS

A retrospective analysis of 10 patients after cardiac surgery who developed DSWI in the period 2010-2012 was performed. After 3 months of ineffective conventional therapy including targeted antibiotic, surgical sternal debridement and NPWT, patients were qualified for additional HBO2 therapy. A total of 20 sessions of HBO2 therapy were performed, each 92 minutes long.

RESULTS

After 4 weeks of HBO2 treatment, 7 patients presented complete wound healing with fibrous scar formation. One patient was qualified for the another cycle of HBO2 therapy with 20 additional sessions, and complete wound healing was observed. In 2 cases, after 5 and 19 sessions, HBO2 was interrupted because of improper qualifications.

CONCLUSIONS

The HBO2 as an additional therapy in DSWI was successful in 80% of cases, and no complications were observed. However, due to the small number of published studies with a small number of patients, randomized, clinical trials are needed to assess the clinical results of HBO2 in DSWI after cardiac surgery procedures.