Department of Gastroenterology and Nephrology;
Graduate School of Medicine;
Chiba University;
Chiba 260-8670;
Japan;
Department of Gastroenterology;
Kitasato University School of Medicine;
Kanagawa 252-0375;
Japan;
Department of Gastroenterology;
Asahi Central Hospital;
Chiba 289-2511;
Japan;
Division of Gastroenterology and Hepatology;
Department of Internal Medicine;
Toho University Ohashi Medical Center;
Tokyo 153-8515;
Japan;
Gastroenterology Medicine Center;
Shonan Kamakura General Hospital;
Kanagawa 247-8533;
Japan;
Department of Gastroenterology;
Subaru Health Insurance Society Ota Memorial Hospital;
Gunma 373-8585;
Japan;
Department of Gastroenterology;
Tokyo Metropolitan Cancer and Infectious Diseases Center;
Komagome Hospital;
Tokyo 113-8677;
Japan;
Elderly; patients; Metallic; stent; Malignant; biliary; obstruction;