HES group Control group
Hepato-biliary-pancreatic surgery 29 29
Liver surgery 14 16
Living donor for liver transplantation 7 6
Living donor for renal transplantation 2 2
Upper gastrointestinal surgery 6 8
Lower gastrointestinal surgery 30 20
Urologic surgery 11 15
Gynecologic surgery 1 2
Orthopedic surgery 4 2
Neurosurgery 3 5
Others 2 4
Total 109 109
Table 2: Types of surgical procedures performed in each group.