[1] Iran University of Medical Sciences,Minimally Invasive Surgery Research Center
[2] Rasoule-Akram Hospital,Department of Epidemiology and Biostatistics, School of Public Health
[3] Tehran University of Medical Sciences,Center of Excellence for Minimally Invasive Surgery Training
[4] Iran University of Medical Sciences,undefined
[5] Center of Excellence of European Branch of International Federation for Surgery of Obesity,undefined