Sequential versus contemporaneous portal and arterial reperfusion during liver transplantation. Hemodynamic profiles during piggyback liver grafts using arterial or portal revascularization. Rocuronium profile during orthotopic liver transplantation: effect of changing the order of vascular clamp release at reperfusion of the hepatic graft. Randomized controlled trial to evaluate flush and reperfusion techniques in liver transplantation. Retrograde reperfusion via vena cava lowers the risk of initial nonfunction but increases the risk of ischemic-type biliary lesions in liver transplantation--a randomized clinical trial. Hemodynamic profile and tissular oxygenation in orthotopic liver transplantation: Influence of hepatic artery or portal vein revascularization of the graft.
Although sequential portal and arterial revascularization (SPAr) is the most common method of graft reperfusion at liver transplantation (OLT), contemporaneous portal and hepatic artery revascularization (CPAr) has been used to reduce arterial ischemia to the bile ducts. The aim of this study was to prospectively compare SPAr (group 1; n=19) versus CPAr (group 2; n=21) among 40 consecutive OLT from heart-beating donors. There were no differences in the demographics characteristics, Model for End-stage Liver Disease scores, indication for OLT and donor parameters between the groups. OLT was performed using the piggyback technique. The biliary anastomosis was performed in all cases by a duct-to-duct technique with a T-tube in 32% versus 29% of cases without a T tube (P=.83). In the CPAr group, the liver was reperfused simultaneously via the portal vein and hepatic artery. CPAr showed a longer warm ischemia (66 ± 8 vs 37 ± 7 minutes; P<.001), while SPAr had a longer arterial ischemia 103 ± 42 vs 66 ± 8 minutes (P=.0004). Recovery of graft function was similar. There was no primary nonfunction and delayed graft function occurred among 10% versus 9%. Liver function tests were similar between the two groups up to 90 days case of follow-up- One-year graft and patient survivals were, respectively, 89% and 95% versus 94% and 100% (P=.29). At a median follow-up of 13 ± 6 versus 14 ± 7 months, biliary complications included anastomotic stenoses in 15% versus 19% (P=.78) and intrahepatic non-anastomotic biliary strictures in 26% versus none (P=.01) for SPAr and CPAr, respectively. CPAr was safe and feasible, reducing the incidence of intrahepatic biliary strictures by decreasing the duration of arterial ischemia to the intrahepatic bile ducts.
                Copyright © 2011 Elsevier Inc. All rights reserved. The order of revascularization in human liver grafts is still discussed. This study tries to answer this question in terms of hemodynamic data.
                Fifty-nine patients were randomized in this study to compare hemodynamic data just before and 15 minutes after revascularization of liver grafts in relation to first hepatic artery (n = 29) or first portal vein (n = 30) revascularization procedure.
                Hemodynamic variations were significantly greater in the portal vein group than in the hepatic artery group in terms of mean arterial pressure, cardiac index, central venous pressure, pulmonary capillary pressure, and systemic vascular resistance. The latter decreased from 741.8 +/- 390.3 to 659.9 +/- 411.1 dynes/ cm5 (NS) in the hepatic artery group versus 807.7 +/-336.7 to 439.7 +/- 215 dynes/cm5 (p < 0.05) in the portal vein group. Clinical results and postoperative complications, graft characteristics, patient survival, and graft survival were not significantly different between the groups.
                Initial arterial revascularization of the liver graft leads to a more stable hemodynamic profile during revascularization of the liver graft after vascular unclamping. This technique is always feasible and has become our reference procedure. Clearance of rocuronium in the neohepatic period may be a criterion for graft function during orthotopic liver transplantation (OLT). Our goal was to demonstrate that changes in rocuronium elimination are caused mainly by variations in blood volume at reperfusion. We have explored the influence on rocuronium plasma concentrations of changing the order of vascular unclamping at graft reperfusion.
                Thirty patients were randomized at graft reperfusion: initial arterial revascularization (IAR; n = 14) wherein the hepatic artery was released first, and initial portal revascularization (IPR; n = 16) wherein the portal vein was released first. Tracheal intubation was facilitated by rocuronium (1 mg/kg) with an infusion initiated at 0.25 mg kg(-1) h(-1) to maintain a response to the first stimulus of the train of four <25% of controls. Rocuronium plasma concentrations (RPC) were measured throughout the transplantation.
                No differences were observed in rocuronium consumption at different stages. RPCs decreased after reperfusion, with primarily portal unclamping responsible. In 6 patients of the IAR group and 5 patients of the IPR group, RPC at 60 minutes after reperfusion was higher than previous values. Indicators of graft dysfunction among those 11 did not differ from the other patients. Two patients in the IPR group required retransplantation without any relation to changes in RPCs.
                The increase of blood flow produced by portal vein unclamping influenced RPCs; no relation was observed between RPCs and graft outcomes. To determine the impact of different flush and reperfusion techniques on postreperfusion syndrome (PRS) and postoperative graft function, 100 transplants were randomly assigned into four groups as follows: group 1 (n=31), portal vein flush, no vena caval venting; group 2 (n=21), hepatic arterial flush, no vena caval venting; group 3 (n=29), portal vein flush with vena caval venting; and group 4 (n=19), hepatic artery flush with vena caval venting. Donor and recipient characteristics were similar. Extensive intraoperative and postoperative monitoring was performed and measurements were documented immediately before reperfusion and at 1, 5, 15, and 30 min after reperfusion. PRS was defined by three criteria: mean arterial pressure (MAP) <60 mmHg at 1 min after reperfusion, MAP <60 mmHg at 5 min after reperfusion, and a decrease of 30% or more for the MAP percent area under the curve during the initial 5 min after reperfusion (%AUC). Using these definitions, the overall incidence of PRS was 21%, 8%, and 43%, respectively. Group 1 was the most hemodynamically stable; the incidence of PRS in group 1 was 2/31 (7%) at 1 min and 8/31 (25%) using %AUC criteria compared with 7/21 (33%) at 1 min and 12/21 (57%) using %AUC criteria for group 2 (P<0.05). The patients in groups 3 and 4 (vena caval venting) demonstrated smaller percentage increases in serum potassium levels (as determined by %AUC; 4.3+/-6.8 and 0.3+/-5.4, vs. 15.1+/-8.1 for group 1 and 22.9+/-8.2 for group 2). The difference between group 4 and group 2 was statistically significant (P<0.05). The increases in serum potassium did not translate into increased cardiac or hemodynamic instability. Combining all data obtained over the first 30 min after reperfusion, there was no statistically significant difference in hemodynamic or biochemical changes noted among the four groups. Postoperative liver function was similar among the four groups. We conclude that portal vein flush without vena caval venting provided a lower incidence of PRS than any other technique. Vena caval venting decreased the release of potassium into the circulation. Postoperative graft function was not significantly affected by flush and reperfusion techniques. Initial nonfunction (INF) and biliary complications such as ischemic-type biliary lesion (ITBL) remain two major complications in clinical orthotopic liver transplantation (OLT). The influence of ischemia and reperfusion injury (I/R) as a significant risk factor for both complications is widely unquestioned. A new reperfusion technique that reduces I/R injury should lead to a reduction in both INF and ITBL. One hundred and thirty two OLT patients were included in this study and randomized into two groups. Group A underwent standard reperfusion with anterograde simultaneous arterial and portal reperfusion and group B received retrograde reperfusion via the vena cava before sequential anterograde reperfusion of portal vein and hepatic artery. Serum transaminase level as a surrogate parameter for I/R injury and serum bilirubin level as a parameter for graft function were significantly reduced during the first week after OLT in group B. INF rate was 7.7% in group A and 0% in group B (P = 0.058). ITBL incidence was 4.55% in group A versus 12.3% in group B (P = 0.053). Retrograde reperfusion seemed to be beneficial for hepatocytes, but was detrimental for the biliary epithelium. The unexplained increased incidence of ITBL after retrograde reperfusion will be focus of further investigation. We performed a prospective, randomized study of adult patients undergoing orthotopic liver transplantation, comparing hemodynamic and tissular oxygenation during reperfusion of the graft. In 30 patients, revascularization was started through the hepatic artery (i.e., initial arterial revascularization) and 10 minutes later the portal vein was unclamped; in 30 others, revascularization was started through the portal vein (i.e., initial portal revascularization) and 10 minutes later the hepatic artery was unclamped. The primary endpoints of the study were mean systemic arterial pressure and the gastric-end-tidal carbon dioxide partial pressure (PCO(2)) difference. The secondary endpoints were other hemodynamic and metabolic data. The pattern of the hemodynamic parameters and tissue oxygenation values during the dissection and anhepatic stages were similar in both groups At the first unclamping, initial portal revascularization produced higher values of mean pulmonary pressure (25 +/- 7 mm of Hg vs. 17 +/- 4 mm of Hg; P < 0.05) and wedge and central venous pressures. At the second unclamping, initial portal revascularization produced higher values of cardiac output and mean arterial pressure (87 +/- 15 mm of Hg vs. 79 +/- 15 mm of Hg; P < 0.05) and pulmonary blood pressure. Postreperfusion syndrome was present in 13 patients (42.5%) in the arterial group and in 11 patients (36%) in the portal group. During revascularization, the values of gastric and arterial pH decreased in both groups and recovered at the end of the procedure, but were more accentuated in the initial arterial revascularization group. In conclusion, we found that initial arterial revascularization of the graft increases pulmonary pressure less markedly, so it may be indicated for those patients with poor pulmonary and cardiac reserve. Nevertheless, for the remaining patients, initial portal revascularization offers more favorable hemodynamic and metabolic behavior, less inotropic drug use, and earlier normalization of lactate and pH values.
                (c) 2006 AASLD
There is currently no evidence to support or refute the use of any specific technique of flushing or reperfusion during liver transplantation. Due to the paucity of data, absence of evidence should not be confused with evidence of absence of any differences. Further well designed trials with low risk of systematic error and low risk of random errors are necessary.