title: Decompression of the portal bed and twice-baseline portal inflow are necessary for the functional recovery of a "small-for-size" graft.
abstract: BACKGROUND
  In partial liver transplant, a reduction in the intrahepatic vascular bed produces a rise in the portal vein flow and the portal venous pressure gradient, leading to endothelial and, thereby, hepatocellular injury and death in a process known as "small-for-size" (SFS) syndrome.
  
  
  OBJECTIVE
  To demonstrate that a calibrated portocaval shunt prevents superfluous inflow in a porcine model of SFS transplant.
  
  
  METHODS
  Donor pigs (15-20 kg) underwent 70% hepatectomy. In 2 groups, a 6 mm (S6) (n = 6) or 12 mm (S12) (n = 6) Gore-Tex shunt was placed between the portal vein and infrahepatic inferior vena cava. In a third group, no portocaval shunt was placed (SFS) (n = 17). Grafts were stored for 5 hours at 4°C and then transplanted into recipients (30-35 kg).
  
  
  RESULTS
  Five-day survival was 29% in SFS, 100% in S6, and 0 in S12. Postreperfusion portal vein flow was 4-, 2-, and 1-times flow at baseline in SFS, S6, and S12, respectively. With respect to portal venous pressure gradient, both the 6- and 12-mm shunts effectively decompressed the portal bed. Aspartate aminotransferase and bilirubin rose and the Quick prothrombin time fell in all animals after reperfusion but improved significantly by day 5 in S6. Serum levels of endothelin-1 remained elevated in SFS and S12 but returned to baseline by 12 hours in S6: 2.76 (2.05-4.08) and 2.04 (1.97-2.12) versus 0.43 (0.26-0.50) pg/mL, respectively (P < 0.05 for both comparisons).
  
  
  CONCLUSIONS
  A calibrated portocaval shunt that maintains portal vein flow about twice its baseline value produces a favorable outcome after SFS liver transplantation, avoiding endothelial injury due to portal hyperperfusion or to hypoperfusion because of excess shunting.
authors.affiliation: Department of Surgery, Institut de Malaties Digestives, Hospital Clínic, CIBERehd, IDIBAPS, University of Barcelona, Barcelona, Spain.
authors.forename: Amelia J
authors.initials: AJ
authors.lastname: Hessheimer
authors.forename: Constantino
authors.initials: C
authors.lastname: Fondevila
authors.forename: Pilar
authors.initials: P
authors.lastname: Taurá
authors.forename: Javier
authors.initials: J
authors.lastname: Muñoz
authors.forename: Olga
authors.initials: O
authors.lastname: Sánchez
authors.forename: José
authors.initials: J
authors.lastname: Fuster
authors.forename: Antoni
authors.initials: A
authors.lastname: Rimola
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: García-Valdecasas
mesh_terms: D000818:Animals; D019299:Decompression, Surgical; D008099:Liver / Q000098:blood supply*; D008102:Liver Circulation; D008107:Liver Diseases / Q000209:etiology*; D016031:Liver Transplantation / Q000009:adverse effects*; D008297:Male; D009929:Organ Size; D011167:Portacaval Shunt, Surgical; D011168:Portal System / Q000601:surgery*; D011169:Portal Vein / Q000503:physiopathology*; D020127:Recovery of Function; D013552:Swine; D019737:Transplants; D014690:Venous Pressure