Efficacy of a novel ultra-tapered endoscopic nasobiliary drainage tube in gallbladder drainage oleh Takaoki Hayakawa, MD, Eisuke Iwasaki, MD, PhD, Haruka Okada, MD, Yuki Nakajima, MD, Atsuto Kayashima, MD, Shintaro Kawasaki, MD, Masayasu Horibe, MD, PhD, Takanori Kanai, MD, PhD