title: How far can we lower graft-to-recipient weight ratio for living donor liver transplantation under modulation of portal venous pressure?
abstract: Smaller size grafts for living donor liver transplantation (LDLT) can enhance donor safety and expand donor availability. We previously reported that modulation of portal venous pressure (PVP) was key for successful LDLT with small grafts, and that it actively lowered graft-to-recipient weight ratio (GRWR) for adult-to-adult LDLT. This retrospective study investigated the outcome of LDLT using small grafts with PVP modulation.
  
  
  
  This study analyzed 221 adult LDLT patients between March 2008 and December 2013 and divided them into 3 groups based on GRWR: large (L), GRWR ≥ 0.8% (n = 154), medium (M), ≥ 0.7% GRWR < 0.8% (n = 38); and small (S) GRWR < 0.7% (n = 29). Donor and recipient factors, PVP, pressure gradient between PVP and central venous pressure (CVP), occurrence of small for size syndrome (SFSS), ascites, and posttransplant laboratory data were compared across the 3 groups. Patient and graft survival were compared using Kaplan-Meier methods.
  
  
  
  There was no difference in patient or graft survival between the 3 groups. Amount of posttransplant ascites and posttransplant International Normalized Ratio were similar, but the S and M groups had more prolonged cholestasis. SFSS was identified in 17%, 13%, and 13% in the S, M, and L groups, respectively (P = NS). Patients with a final PVP of ≤15 mmHg had better survival than patients with a final PVP of >15 mmHg (P < .001). Multivariate analysis showed that donor age >40 years old, final PVP of >15 mmHg, and pressure gradient of PVP-CVP >5 mmHg were risk factors for inferior patient survival.
  
  
  
  We achieved satisfactory outcomes in LDLT with GRWR as low as 0.6% using PVP modulation. Thus, we currently set a lower limit of GRWR at 0.6% while protecting donor safety and expanding donor availability.
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan. Electronic address: tuemura@kuhp.kyoto-u.ac.jp.
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Uemura
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Seidai
authors.initials: S
authors.lastname: Wada
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Toshimi
authors.initials: T
authors.lastname: Kaido
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Mori
authors.affiliation: Department of Transplantation Surgery, Nagoya University, Nagoya city, Aichi, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ogura
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Yagi
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujimoto
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Hata
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yoshizawa
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Okajima
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Uemoto
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006085:Graft Survival; D006801:Humans; D017093:Liver Failure / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D016031:Liver Transplantation; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D017082:Portal Pressure / Q000502:physiology*; D012189:Retrospective Studies; D015996:Survival Rate; D019737:Transplants / Q000473:pathology*; D016896:Treatment Outcome