Christine Stier1, Scott Shikora2, Sonja Chiappetta3, Sylvia Weiner4. 1. Department of Bariatric and Metabolic Surgery, Sana Klinikum Offenbach, Starkenburgring 66, 63069, Offenbach am Main, Hessen, Germany. Christine.stier@googlemail.com. 2. Bariatric Surgery, Department of Surgery, Brigham and Women's Hospital, 75 Francis St., ASBII-3rd Floor, Boston, MA, 02115, USA. 3. Department of Bariatric and Metabolic Surgery, Sana Klinikum Offenbach, Starkenburgring 66, 63069, Offenbach am Main, Hessen, Germany. 4. Krankenhaus Nordwest, Steinbacher Hohl 2-26, 60488, Frankfurt, Germany.