Lalisang, T.J.M., Digestive Surgery Division, Faculty of Medicine Universitas Indonesia, Cipto Mangunkusumo Hospital, Jakarta, Indonesia; Situmorang, I., Surgery Department, Pelni Hospital, Jakarta, Indonesia; Ibrahim, F., Digestive Surgery Division, Faculty of Medicine Universitas Indonesia, Cipto Mangunkusumo Hospital, Jakarta, Indonesia; Widianto, P., Surgery Department, Persahabatan Hospital, Jakarta, Indonesia; Marbun, V.M.G., Digestive Surgery Division, Faculty of Medicine Universitas Indonesia, Cipto Mangunkusumo Hospital, Jakarta, Indonesia