Clinical And Experimental Study Of Modulating Venous Pressure During Liver Transplantaion

Partâ… Clinical and experimental study of modulating venous pressure for recipients during liver transplantationIntroductionWith the development of the surgical technology,the progress in the organ preserve methods,the usage of new immunology inhibitor medicine as well as the achievement of the immunology therapy,liver transplantation has become the solely measure to rescue all kinds of the end stage liver diseases.Now the main perioperation problem of liver transplantation for recipients is:(1)Liver transplantation may be associated with massive blood loss and then need for massive blood product transfusion.Recent studies show that intraoperative transfusion of packed red blood cells was associated with a significant decrease of the 3-month and 1-year survival rate.Other side effects related with the massive transfusion during the liver transplantation were the high risk for the intestinal complication,the infection and the inclination for the acute allograft rejection reaction.(2)Compared with total liver transplantation,living donor liver transplantation always connected with questions as small—size- for graft,leading to relatively or absolutely increase in blood volume,afterwards the portal venous hypertension will occur.Animal experiments and clinic research had both proved that the hypertension of the portal vein and excess prerfusion of the portal system could affect the recovery and regeneration of the new liver cell,as well as the survival of the graft and the receptor.Therefore,how to reduce the bleeding and transfusion volume during the operation,how to prevent the small-for-size graft syndrome and how to protect the new liver have become the hot points in this research realm.The aim of the present study was to investigate the effect of lowing central venous pressure during the preanhepatic phase about the bleeding volume and to study the possible protective mechanism about graft function during the neohepatic phase by the adjustment of the portal venous pressure by lowing central venous pressure.Materials and methods1.Patient characteristicsFrom Sep 2006 to Jan 2008,48 cases of adult cadaveric liver transplantation and 38 cases of living liver transplantation in our institution were enrolled in this prospective study.2.MethodsThe recipients were randomized into two groups:experimental and control group,according to the usage of nitroglycerin,somatostatin,and the limitation of infusion.Those ways are used for controlling the central vein pressure in preanhepatic phase and adjusting portal venous pressure in neohepatic phase.3.Variables1)Recipient and donor's clinical and demographic characteristics. 2)Perioperative hemodynamic variables including portal venous pressure3)Perioperative oxygen delivery,oxygen consumption,lactic acid concentration, pH and so on.4)Bleeding volume,urine volume,fluid and blood product administration during operation.5)Perioperation liver function,including total bilirubin,alanine aminotransferase, aspartate aminotransferase and prothrombin time.6)Perioperation renal function,including creatinine and urea nitroglycerin.7)Postoperative hospitalization and recovery of gut function.8)Postoperative morbidity and mortality.9)Perioperative ET-1,NO and TNF-αwere determined by enzyme linked immunosorbent assay(ELISA).10)Pathological histology examination of transplanted liver 2h after reperfusion.11)Expression of the ET-1,NO,HO-1and TNF-αin transplanted liver 2h after reperfusion by immunohistochemistry analysis.4.Statistical AnalysisData were analyzed using SPSS15.0 for Windons XP version.Data were tested for normality using the Kolmogorov-Smirnov test.Parametric data were expressed as mean±standard deviation of the mean,and analyzed using appropriate ANOVA or Student's t -test and non-parametric data were analyzed using the Mann-Whitney U test.Data were considered significant at a level of P＜0.05. ResultThe low central venous pressure was keeped in 86%of recipients successfully during anhepatic phase in experiment group.2 CVP was not reduced obviously during anhepatic phase in 6 cases of experiment group,who manifested as the hyperdynamic circulaion more severely.3 CVP,PAWP and PVP during preanhepatic phase in experiment group were lower than those in control group.4 CVP,CO and DO₂I during anhepatic phase in experiment group were higher than those in control group.5 Lactate during neohepatic phase in experiment group was lower than that in control group.6 There were no significant difference in perioperative oxygen consumption index and renal function between control group and experiment group.7 Intraoperative bleeding volume,blood pruduct administration and fluid infusion volume in experiment group were less than those in control group.8 Postoperative intubation time in experiment group was shorter than that in control group.9 There were no significant difference in morbidity and mortality between the experiment group and control group.10 ALT and AST during neohepatic phase in experiment group were lower than those in control group.11 Blood ET-1 concentration during neohepatic phase in experiment group was lower than that in control group. 12 ET-1and TNF-αexpressed in the transplanted liver in experiment group were less than those in the control group.ConclusionsLowing central venous pressure by nitroglycerin,somatostatin,limiting fluid infusion during preanhepatic phase for recipients in liver transpatation is effective and feasible.2 Lowing central venous pressure during preanhepatic phase contributes to limit blood losses and hence lead to a decreased blood product administration,as well as shortening the postoperative intubation time.3 Lowing central venous pressure by nitroglycerin,somatostatin,limiting fluid infusion during preanhepatic phase for recipients in liver transpatation is safe.4 Lowing central venous pressure during operation contributes to attenuate portal venous pressure and protect graft function,the mechanism maybe related with the inhibition of the intragraft expression of the ET-1. IntroductionThe shortage of available brain-dead organ donors continues to limit cadaveric liver transplantation.For this reason,living-donor liver transplantation is now accepted as an established treatment modality for patients with end-stage liver disease.Important advantages are provided for the recipient:the recipient can be prepared optimally for an elective operation,and a graft with a relatively shorter cold ischemia time is transplanted usually earlier in the course of the recipient's end-organ failure.However, there is considerable debate concerning the ethical aspect of imposing the risk of such major surgery and anesthesia on healthy individuals "only" for the sakeof the recipient. Therefore,when considering living donor liver transplantation,donor safety must be paramount.Unfortunately,there have been reports of surgical and medical complications and even mortalities during living donor hepatectomies(LDHs)in North America,Europe,and Asia.To minimize the possible risks to which a living donor may be exposed during living donor liver transplantation,it seemed reasonable to avoid blood transfusion,because intraoperative blood transfusion has been associated with increased perioperative morbidity and mortality ratios in liver surgery.It has been reported that lowering central venous pressure reduces blood loss and transfusion requirements during major liver surgery and during LDHs.However,despite these possible beneficial effects,other workers have disputed the safety of this approach. Schroeder et al have shown that a low central venous pressure fluid management strategy was associated with higher mortality and morbidity rates among their orthotopic liver transplantation patients.And Ayanoglu et al have reported that the perioperative complication included an air embolism during hepatic resection in one patient.So the safety for lowing central venous pressure technology during LDHs still under further investigation.The aim of this study was to determine the perioperative complications with low central venous pressure and the influence of different anesthesia methods on lowing central venous pressure and on it's safety during LDHs.Material and methods1.Objective:40 LDHs were performed from Dec 2006 to Jan 2008 in our institute.All of donor were volunteers without any payment and were granted by our Hospital Ethics Committee.Preoperative patient evaluation included organ coordinator evaluation,psychiatric,surgeon,and anesthetic evaluation.All patients were ASA I physical status.2.Groups:According to the different anesthesia methods,the donors are randomized divided into two groups:general anesthesia group(Group A)and general anesthesia combined with epidural block anesthesia group(Group B).3.Analyzed data1)Donor's demography,the type of lobectomy;2)Intraoperative hemodynamic parameters;3)Intraoperative blood loss,transfusion requirements,crystalloid and colloid requirements,and intraoperative urine output; 4)Perioperative lactic acid level,blood gas analysis and blood sugar;5)Perioperative liver function,renal function and coagulation function;6)Intraoperative and perioperative complications.4.Statistical AnalysisData were analyzed using SPSS15.0 for Windons XP version.Data were tested for normality using the Kolmogorov-Smimov test.Parametric data were expressed as mean±standard deviation of the mean,and analyzed using appropriate ANOVA or Student's t -test and non-parametric data were analyzed using the Mann-Whitney U test.Data were considered significant at a level of P＜0.05.Results1.The group A did not sucesse in lowing central venous pressure until liver parenchymal transection,while the group B reached lowing central venous pressure immediately and keeped with low central venous pressure both prehepatectomy and intra-hepatectomy.2.The perioperative mean blood pressure were more stable in Group B than those in Group A.3.Blood loss was less in Group B than that in Group B.4.Both groups requied no blood transfusion perioperatively.5.The changes in ALT,AST,TB and PT with respect to the preoperative levels remained significant until POD7 or POD 14 in both group,and there were no significantly different between the two groups. 6.There was no intraoperative complication of air embolism and so on in both groups.7.There was no significantly change of renal function perioperation in both groups.8.All donors recovered well and survived with relatively few complications,and there was no difference between the two groups in postoperative complications.Conclusions1.Low central venous pressure contributed to a better operation condition for surgery and reduced the blood loss during living donor hepatectomy.2.The application of low central venous pressure is safe in living donor hepatectomy.3.Comparing with the general anesthesia,the central venous pressure was easier to control and keep and the blood pressure was more stale in general anesthesia combined with epidural block anesthesia.4.Both anesthetic techniques were well tolerated for living donor hepatectomy, with no significantly different influence on significant laboratory changes reflecting transient impairment in liver function.5.It is safe for epidural puncture and postoperative epidural analgesia for donor undergoing living donor hepatectomy.