1 Contilia Center for Esophageal Diseases, Elisabeth-Hospital Essen, Cooperation Partner of West German Tumor Center, University Medicine Essen, Klara-Kopp-Weg 1, 45138 Essen, Germany.
2 Department for General-, Visceral-, Thoracic-, Pediatric- and Endocrine Surgery, Johannes Wesling Hospital, University Clinic Ruhr University Bochum, Hans-Nolte-Str. 1, 32429 Minden, Germany.