title: Orthotopic liver transplantation without venovenous bypass using the conventional and piggyback techniques.
abstract: BACKGROUND
  Orthotopic liver transplantation is a widely used procedure for the treatment of irreversible liver diseases for which there is no possibility of medical treatment. When this procedure is performed by the conventional technique, the retrohepatic vena cava is removed along with the native liver. The inferior vena cava (IVC) remains clamped until the revascularization of the graft, and in this period there is a reduction in the venous return, which may induce a fall by up to 50% in the cardiac output with hemodynamic instability and a fall in renal perfusion pressure. The use of a portal-femoral-axillary venovenous bypass system, in which the blood from the femoral and portal veins returns to the heart via the axillary vein propelled by a centrifugal pump, is intended to minimize the effects of the IVC clamping. In the piggyback (PB) technique, the native liver is removed and the IVC of the recipient is preserved and only partially clamped. We have employed both techniques without the use of venovenous bypass for 10 years. The objective of this study was to compare the results obtained from the use of the two techniques.
  
  
  METHODS
  A retrospective analysis was performed of 195 patients transplanted between 1999 and 2008: 125 by the conventional technique and 70, the PB technique. The intraoperative parameters were analyzed (surgical time, ischemia time, use of blood products, and diuresis), as well as intensive care support (duration of stay in intensive care unit and use of vasoactive drugs), period of intubation, length of hospital stay, renal function, graft function, postoperative complications, retransplantation, and patient survival.
  
  
  RESULTS
  The PB group showed a reduction in surgical time, warm ischemia time, the use of packed red blood cells concentrates, and fresh frozen plasma, as well as mortality at 30 days (P<.05). There were no differences in relation to cold ischemia time, intraoperative diuresis; length of stay and use of vasoactive drugs in the intensive care unit; the period of intubation; the duration of hospital stay; the renal function; the graft function; the need for reoperation; the incidence of sepsis, biliary complications, vascular complications; need for retransplantation; and 1-year mortality. The cumulative survival rate at 1 year was significantly better among the PB patients.
  
  
  CONCLUSIONS
  Orthotopic liver transplantation can be performed without venovenous bypass with good results, using either the conventional technique or the PB technique. Provided that there is no technical contraindication and a long ischemia period is not foreseen, the PB technique should be the technique of choice.
authors.affiliation: Department of Surgery and Liver Transplantation, Oswaldo Cruz University Hospital, University of Pernambuco, Recife City, Pernambuco State, Brazil. paulosvm@yahoo.com.br
authors.forename: P S
authors.initials: PS
authors.lastname: Vieira de Melo
authors.forename: L E C
authors.initials: LE
authors.lastname: Miranda
authors.forename: L L
authors.initials: LL
authors.lastname: Batista
authors.forename: O C L F
authors.initials: OC
authors.lastname: Neto
authors.forename: A G
authors.initials: AG
authors.lastname: Amorim
authors.forename: B D
authors.initials: BD
authors.lastname: Sabat
authors.forename: H L L
authors.initials: HL
authors.lastname: Cândido
authors.forename: L C L
authors.initials: LC
authors.lastname: Adeodato
authors.forename: R S
authors.initials: RS
authors.lastname: Lemos
authors.forename: G L
authors.initials: GL
authors.lastname: Carvalho
authors.forename: C M
authors.initials: CM
authors.lastname: Lacerda
mesh_terms: D000328:Adult; D000368:Aged; D001803:Blood Transfusion; D001938:Brazil; D016009:Chi-Square Distribution; D003250:Constriction; D005112:Extracorporeal Circulation; D005260:Female; D006439:Hemodynamics; D006801:Humans; D053208:Kaplan-Meier Estimate; D016031:Liver Transplantation / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D014682:Vena Cava, Inferior / Q000503:physiopathology / Q000601:surgery*; D052096:Warm Ischemia; D055815:Young Adult