1-      Oxford University, Radcliffe Hospital, Colorectal Surgery, Oxford, UK. 1995-1996.

2-      Oxford University, Radcliffe Hospital, Hepatobiliary Surgery, Oxford, 1995-1996.

3-      Oxford University, Radcliffe Hospital, Gastrointestinal Pathology, Oxford, UK. 1995-1996.

4-      University of Pittsburgh, Schools of Health Sciences and UPMC, USA. 2000.

5-      University of Pittsburgh, Department of Surgery, USA. 2000.

6-      Chirurgische Klinik des Klinikums rechts der ısar der Technischen Universitat München, Munich, Germany. 2001.

7-      Lichtenstein Hernia Institute, Los Angeles, CA, USA. 2004.

8-      Plymouth Hernia Service, Plymouth, UK. 2006.

9-      British Hernia Center, London, UK. 2006.

10-  Hospital of Leoben, Austria, 2007.