1. Department of Plastic- Reconstructive- and Hand surgery, Haaglanden Medical Center, Den Haag
2. Department of Intensive Care Medicine, Elisabeth-Tweesteden Ziekenhuis, Tilburg
3. Faculty of Health, Witten/Herdecke University, Witten
4. Department of General, Abdominal Surgery and Coloproctology, Helios St. Elisabeth Klinik, Oberhausen, NRW, Germany
5. Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands