Observational cohort study.

Lung emphysema is often associated with chronic obstructive pulmonary disease (COPD) and is an incurable disease. Dyspnea is the main, debilitating symptom and is relieved by inhaled bronchodilators and rehabilitation. However, a substantial number of patients continue to suffer from dyspnea and among these, many patients have severely hyperinflated lungs due to predominant emphysema.

For selected patients, one-way endobronchial valves (EBV) can be inserted in the bronchial system using a bronchoscope and it has emerged as a valid treatment option, with reduction of hyperinflation and increasing pulmonary function, quality of life, and exercise capacity in approximately 2/3 of the patients. EBV poses a risk of adverse events with the most common being pneumothorax, followed by infection and valve dysfunction. Such incident complications may require a re-intervention with bronchoscopic cleaning, complete removal or reinsertion of the EBVs.

Former studies have shown increased growth of potential pathogenic bacteria in sputum following EBV in patients, who developed chronic infection and/or valve dysfunction, but no studies have investigated the microbiome on the time of EBV insertion with non-culture based methods of bacterial sequencing.

In this study, we will define the microbiome through 16S RNA sequencing at time on EBV insertion and at time of possible valve removal or cleaning, to investigate the connection between specific potentially pathogenic microorganisms and the risk of infections and need for re-interventions. We hope these results decrease the risk of re-interventions and complications in future in this fragile group of patients, through antibiotic treatment and improvement of patient selection.

The project is a collaboration between Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Department of Respiratory Medicine and Allergy, Aarhus University Hospital, Department of Microbiology, Aarhus University Hospital, Department of Cardiothoracic and Vascular Surgery, Odense University Hospital, Department of Respiratory Medicine and Allergy, Odense University Hospital and The Heart Center, Rigshospitalet.

• Kirstine Hermann Jørgensen, MD, PhD-student, Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Department of Respiratory Medicine and Allergy, Aarhus University Hospital, Aarhus, Denmark
• Elisabeth Bendstrup, Professor, MD, PhD, consultant, Department of Respiratory Diseases and Allergy & Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
• Thomas Decker Christensen, Professor, MD, DMSc, PhD, Consultant, Department Cardiothoracic and Vascular Surgery  & Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
• Michael Perch, Associate Professor, MD, PhD, Consultant, The Heart Center, Rigshospitalet, Copenhagen, Denmark
• Ole Dan Jørgensen, Associate Professor, MD, PhD, Consultant, Department of Cardiothoracic and Vascular Surgery, Odense University Hospital, Odense, Denmark
• Arman Arshad, Lead Consultant, MD, Department of Respiratory Medicine, Odense University Hospital, Odense, Denmark
• Ingrid Titlestad, MD, PhD, Consultant, Department of Respiratory Medicine, Odense University Hospital, Denmark
• Jesper Rømhild Davidsen, MD, PhD, Clinical Associate Professor, Consultant, Department of Respiratory Medicine, Odense University Hospital, Odense, Denmark
• Kristine Jensen, MD, The Heart Center, Rigshospitalet, Copenhagen, Denmark
• Morten Bendixen , MD, PhD, Consultant, Department Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark
• Mikala Wang, MD, PhD, Consultant, Department of Clinical Microbiology, Aarhus University Hospital, Aarhus, Denmark
• Niels Nørskov, Professor, MD, PhD, Consultant, Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark

The project has received funding from Karen Elise Jensen Fonden.