Analysis of pancreaticoduodenectomy for elderly patient 80 years or older. (2019) - Kita, Sadahiko; Awane, Masaaki; Yoshimura, Naoki; Matsumura, Yasumitsu; Mizuno, Katsuhiko; Araki, Yoshiro; Takeda, Ryoji; Takahashi, Shigeru