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

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

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

Regenerative Medicine for the Treatment of Ischemic Heart Disease; Status and Future Perspectives

Cardiovascular disease is now the leading cause of adult death in the world. According to new estimates from the World Health Organization, myocardial infarction (MI) is responsible for four out of every five deaths due to cardiovascular disease. Conventional treatments of MI are taking aspirin and nitroglycerin as intermediate treatments and injecting antithrombotic agents within the first 3 h after MI. Coronary artery bypass grafting and percutaneous coronary intervention are the most common long term treatments. Since none of these interventions will fully regenerate the infarcted myocardium, there is value in pursuing more innovative therapeutic approaches. Regenerative medicine is an innovative interdisciplinary method for rebuilding, replacing, or repairing the missed part of different organs in the body, as similar as possible to the primary structure. In recent years, regenerative medicine has been widely utilized as a treatment for ischemic heart disease (one of the most fatal factors around the world) to repair the lost part of the heart by using stem cells. Here, the development of mesenchymal stem cells causes a breakthrough in the treatment of different cardiovascular diseases. They are easily obtainable from different sources, and expanded and enriched easily, with no need for immunosuppressing agents before transplantation, and fewer possibilities of genetic abnormality accompany them through multiple passages. The production of new cardiomyocytes can result from the transplantation of different types of stem cells. Accordingly, due to its remarkable benefits, stem cell therapy has received attention in recent years as it provides a drug-free and surgical treatment for patients and encourages a more safe and feasible cardiac repair. Although different clinical trials have reported on the promising benefits of stem cell therapy, there is still uncertainty about its mechanism of action. It is important to conduct different preclinical and clinical studies to explore the exact mechanism of action of the cells. After reviewing the pathophysiology of MI, this study addresses the role of tissue regeneration using various materials, including different types of stem cells. It proves some appropriate data about the importance of ethical problems, which leads to future perspectives on this scientific method.

Changing trends in aortic valve procedures over the past ten years-from mechanical prosthesis via stented bioprosthesis to TAVI procedures-analysis of 50,846 aortic valve cases based on a Polish National Cardiac Surgery Database

Background

Aortic valve replacement (AVR) is one of the most common surgeries performed in cardiac surgery operating rooms. We present actual, real life trends from the last 10 years for AVR interventions based on a multicentre National Registry of Cardiac Surgery Database.

Methods

The study population consisted of all 50,846 consecutive adult patients who underwent AVR between January 2006 and August 2016 in all cardiac surgery units in Poland. The main outcome measures were changes in the number of valves, characteristics of valves, operative details, and in-hospital mortality. Analysis consisted of all aortic valve (AV) procedures, including isolated AV surgery, combination procedures and patients who had a prior valve operation.

Results

In last 10 years, the number of procedures increased by 46%. Isolated surgical AVR was performed in 61.2%, AVR + coronary artery bypass grafting (CABG) in 23.9%, AVR + mitral valve replacement (MVR) in 7%, and transcatheter aortic valve implantation (TAVI) in 2.3% of patients. The mean patient age increased significantly from 61.4 years in 2006 to 66.1 years in 2016. Aortic stenosis was diagnosed in 73.4%, severe aortic insufficiency in 15.8% of cases. The most common valve pathology was calcification. Congenital valve dysfunction was diagnosed in 3.7% of cases. There was a 33.7% increase of bioprosthesis, and the most common implanted bioprosthesis was the Hancock II. The most common implanted mechanical prosthesis was the St. Jude Medical Mechanical Valve. In-hospital mortality decreased significantly over the 10-year period in all AV procedures from 10.9% in 2006 to 8.3% in 2016. Mean in-hospital mortality was: 4.0% in isolated surgical AVR, 5.4% in TAVI, 6.8% in AVR + CABG, 9.8% in AVR + MVR, 17.2% in AVR + MVR + CABG.

Conclusions

In the last ten years, the number of AV procedure has doubled. Mortality was significantly lower with all types of AV procedure despite very rapid aging of AVR patients. TAVI procedure rapidly grew in popularity. There is significant increase in the use of bioprosthesis.

Ministernotomy or sternotomy in isolated aortic valve replacement? Early results

Introduction

Aortic valve replacement (AVR) is the gold standard in treating symptomatic aortic valve defects. To improve the healing process and limit the trauma, the minimally invasive approach was introduced.

Aim

To compare the peri- and post-operative results of aortic valve replacement performed via conventional full sternotomy (con-AVR) and of AVR performed via partial upper sternotomy (mini-AVR).

Material and methods

The total study population was divided into 2 demographically homogeneous groups: mini-AVR (n = 74) and con-AVR (n = 76). There were no statistically significant differences in preoperative echocardiography.

Results

Aortic cross-clamp time and cardiopulmonary bypass time were significantly longer in the mini-AVR group. Shorter mechanical ventilation time, hospital stay and lower postoperative drainage were observed in the mini-AVR group (p < 0.05). Biological prostheses were more frequently implanted in the mini-AVR group (p < 0.05). Patients from the mini-AVR group reported less postoperative pain. No significant differences were found in the diameter of the implanted aortic prosthesis, the amount of inotropic agents and painkillers, postoperative left ventricular ejection fraction (LVEF), medium and maximum transvalvular gradient or the number of transfused blood units. There were no differences in the frequency of postoperative complications such as mortality, stroke, atrial fibrillation, renal failure, wound infection, sternal instability, or the need for rethoracotomy.

Conclusions

Ministernotomy for AVR is a safe method and does not increase morbidity and mortality. It significantly reduces post-operative blood loss and shortens hospital stay. Ministernotomy can be successfully used as an alternative method to sternotomy.

Mid-term follow-up after suture-less aortic heart valve implantation

Background

Aortic stenosis (AS) is the most common valve disease in the adult population and its prevalence increases with age. Unfortunately, older age and comorbidities significantly increase mortality, operative risk and worsen prognosis. In recent years, sutureless bioprosthesis [sutureless-aortic valve replacement (SU-AVR)] has become an alternative to standard AVR or TAVI in high-risk patients. Compared to standard AVR, the advantages of SU-AVR include shorter valve implantation, shorter aortic cross clamp (ACC) and cardiopulmonary bypass (CPB) times and higher valve EOA with more favorable hemodynamic parameters. Good early clinical and hemodynamic outcomes have been reported in several studies. However, although early SU-AVR results reported in the literature are encouraging, there are few results of long term follow-up. The aim of this study is to present long term echocardiographic hemodynamic outcomes of the Enable sutureless bioprosthesis.

Methods

The first human implantation of the Enable sutureless bioprosthesis was performed on the 13th January, 2005 by the authors of this manuscript. From that time until July 2008, 25 patients underwent isolated SU-AVR implantation. The median preoperative logistic EuroSCORE was 1.92±0.17 [standard deviation (SD)] and the STS score was 2.96±2.73. Preoperatively, 65.4% of patients were in NYHA class III or IV, the peak/mean gradient transaortic gradient was 84.6/52.1 mmHg.

Results

After the SU-AVR procedure, the average peak/mean aortic gradients were respectively: 12.9/7.1 mmHg at the intraoperative time; 18.1/9.5 mmHg at 3-6 months; 18.3/9.6 mmHg at 11-14 months; 16.9/9.3 mmHg at 2 years; 15.3/8 mmHg at 3 years; 13.4/7.1 mmHg at 4 years; 16.7/8.9 mmHg at 5 years follow-up. Other hemodynamic echocardiographic parameters such as LVOT diameter, LVOT peak velocity, LVOT TVI, valve peak velocity and valve TVI were stable during the follow-up period.

Conclusions

In summary, sutureless bioprostheses are safe and effective treatments for valve stenosis with excellent outcomes and hemodynamic profile which remained stable during the follow-up period. The peak and mean gradients were 16.7 and 8.9 mmHg, respectively, over a 5-year follow-up period.

The use of stem cells in ischemic heart disease treatment

Ischemic heart disease is a major cause of death and disabilities worldwide. Unfortunately, not all patients are suitable for direct revascularization. Cell-based therapies may be alternative options because of their potential to promote neovascularisation and endothelial repair, improving myocardial perfusion. The success of cell-based therapies depends on the type of implanted stem cells, delivery method and underlying disease. Several different cell populations including bone marrow-derived mononuclear cells (MNCs), mesenchymal stromal cells (MSCs), CD34+, CD133+, endothelial progenitor cells, adipose-derived mesenchymal stromal cells (ASCs) and stem cells from placenta and umbilical cord have been investigated. Presently, no consensus exists about the best cell type for clinical regenerative therapy. Because the system of coronary arteries in the ischemic area is poor and most of the coronary artery is significantly narrowed or closed, direct implantation of stem cells in the ischemic area of the heart muscle appears an attractive method.

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

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

Sternal wound infections following cardiac surgery and their management: a single-centre study from the years 2016-2017

Introduction

Despite improvements in surgical management, sternal wound infection (SWI) following cardiac surgery remains a significant complication.

Aim

To evaluate pathogens involved in SWI following median sternotomy.

Material and methods

We enrolled 164 patients who experienced prolonged sternal wound healing following open-heart surgery. The inclusion criteria were as follows: prolonged sternal wound healing following cardiac surgery via median sternotomy and complete results of microbiological culture obtained from the sternal swab. The exclusion criteria were as follows: partial sternotomy, patients with mechanical sternum dehiscence and incomplete clinical data. Swabs provided information on the type of microorganism present in the wound and the susceptibility of the microorganism to specific antibiotics.

Results

One hundred and fourteen (69.5%) patients aged 68 (interquartile range: 60–76) years developed SWI with positive culture. The in-hospital mortality rate was 21.0% in this group. The most common pathogens included Staphylococcus epidermidis (26.6%), Enterococcus faecium (12.2%), Staphylococcus aureus (11.4%), Klebsiella pneumoniae (8.4%), and Pseudomonas aeruginosa (6.8%). In most of the cases the isolated Staphylococcus epidermidis was methicillin-resistant (n = 57, 43.5%). Enterococcus faecium was vancomycin-resistant in 11 (8.3%) cases and high-level aminoglycoside resistant (HLAR) in 13 (9.9%) cases. Klebsiella pneumoniae had the extended-spectrum β-lactamase (ESBL) mechanism in 14 (10.6%) cases. Among 114 culture-positive patients, 48 (42.1%) had polymicrobial infection of the sternal wound.

Conclusions

Microorganisms associated with SWI in our study were mainly commensals, with the most common pathogen being Staphylococcus epidermidis.

Is sternal rewiring mandatory in surgical treatment of deep sternal wound infections?

Background

Deep sternal wound infections (DSWIs) are a rare but serious complication after median sternotomy, and treatment success depends mainly on surgical experience. We compared treatment outcomes after conventional sternal rewiring and reconstruction with no sternal rewiring in patients with a sternal wound infection.

Methods

We retrospectively enrolled patients who developed a DSWI after an open-heart procedure with median sternotomy at the Department of Cardiac Surgery, at the St. Rafael Hospital, Zalaegerszeg, Hungary, between 2012 and 2016. All patients received negative pressure wound and antibiotic therapy before surgical reconstruction. Patients were divided into groups determined by the reconstruction technique and compared. Subjects were followed up for 12 months, and the primary end-points were readmission and 90-day mortality.

Results

Among 3,177 median sternotomy cases, 60 patients developed a DSWI, 4 of whom died of sepsis before surgical treatment. Fifty-six patients underwent surgical reconstruction with conventional sternal rewiring (23 cases, 41%) or another interventions with no sternal refixation (33 cases, 59%). Eighty-one percent of sternal wound infections followed coronary bypass surgery (alone or combinated with another procedures), and 60% were diagnosed after hospital discharge. Staphylococcus aureus was cultured in 30% of all wounds and, 56.5% of cases reconstructed by sternal rewiring vs. 26.5% with no sternal rewiring, (P=0.022). Hospital readmission occurred in 63.6% of the sternal rewiring group vs. 14.7% of the no sternal rewiring group. The rate of death before wound healing or the 90^th postoperative day was 21.7% in the sternal rewiring group vs. 0% in the no sternal rewiring group. The median hospital stay was longer in the sternal rewiring group than in the other group (51 vs. 30 days, P=0.006).

Conclusions

Sternal rewiring may be associated with a higher rate of treatment failure than other forms of treatment for sternal wound infections.

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.