1 Department of General and Visceral, Vascular and Paediatric Surgery, Saarland University, Homburg/Saar, Germany. ddoll@gmx.de.
2 Department of Procto-Surgery, St. Marienhospital Vechta, Academic Teaching Hospital of the Medizinische Hochschule Hannover, Marienstr. 6-8, 49377, Vechta, Germany. ddoll@gmx.de.
3 Vechtaer Institut für Forschungsförderung VIFF e.V., Vechta, Germany. ddoll@gmx.de.
4 Department of Anaesthesiology and Pain Medicine, Bern University Hospital Inselspital, Bern, Switzerland.
5 Department of Surgery, Logan Hospital, Corner Meadowbrook and Loganlea Roads, Meadowbrook, QLD, 4133, Australia.
6 Griffith Health Centre, Griffith University Medical School, Griffith University Queensland, G40 Gold Coast Campus, Brisbane, QLD, 4222, Australia.