The Clinical Significance Of Artery Steal Syndrome In Liver Transplantation

ObjectivesArtery steal syndrome after liver transplantation is characterized by hepatic arterial hypoperfusion of the graft,which is caused by a shift in blood flow into a different arterial branch originating from the same trunk .As one of the important causes of graft ischemia ,it has been reported in a small published series and hasn't been recognized by clinicians.This study is about the case analysis of 4 patients who had artery steal syndrome after Liver Transplantation.We initially discuss the diagnosis and treatment of artery steal syndrome following liver transplantation.Methods4 cases of the 193 liver transplantation patients were diagnosed as"splenic artery steal syndrome"by Contrast enhanced ultrasound,for Doppler ultrasound revealed that the flow of hepatic artery was disappeared or little ,with high resistive index and splenic artery and portal venous hyperfusion after liver transplantation.All 4 patients were finally diagnosed by celiac angiography and treated by splenic artery embolization;one of whom had developed to hepatic arterial thrombosis,was successfully treated by splenic artery embolization and continous infusion of urokinase through hepatic artery with catheter;Results10 patients died during the liver transplantation ,the mortality of operation is 5.18%; 4 patients exerienced artery steal syndrome after liver transplantation ,the incidence of the disease is 2.2% in our institution .The flow of hepatic artery of the four patients quickly returned to normal pattern after splenic artery embolization.Post-embolization angiogram showed the increased common hepatic arterial perfusion and the opacification of the intrahepatic arterial tree and the decreased of splenic artery flow .After 24 hours ,the ultrasonography images after splenic artery embolization showed markedly increased flow in the commom hepatic artery which returned to normal waveform.Follow up ranged from 6 month to 18 month.The functions of transplant liver were normal and no complications of embolization occurred in follow up.ConclusionsArtery steal syndrome following liver transplanation,a scarce complication of hepatic artery,it could cause severe graft injury,and should be diagnosed and treated early as soon as possible.Contrast enhanced ultrasound is an effective method in early diagnose of artery steal syndrome .Interventional embolization to artery steal is the optimal method of the treatments available because of minimally invasive,immediate clinical improvement and low incidence of complications and continous infusion of urokinase through hepatic artery with catheter simultaneity when the patients had concomitant hepatic arterial thrombosis. PartⅡ.The high risk factors and Prophylactic treatment of artery steal syndromeObjectives:To study and analyze the high risk factors of artery steal syndrome (ASS) so as to provide a certain theoretical evidence to prophylactic and treatment of ASS and To evaluate the therapeutic effect of ligation of splenic artery and other prophylactic approachs to ASS.Methods:A retrospective analysis of 193 patients who underwent Orthotopic Liver Transplantation(OLT) at the Department of Liver Transplantation of the General Hospital of GuangZhou Military Command between August 2003 and December 2009. Based on the diagnosis criterion that the diameter of the splenic artery or gastroduodenal artery was larger as l.5 times more than the hepatic artery as artery steal phenomenon(ASP) that literature have reporated, we identify whether the patients had artery steal phenomenon before undergoing OLT. All patients were devided into two groups,the one had artery steal phenomenon( ASP-group) as the case group,the other one didn't have artery steal phenomenon (NASP-group) as the control group. The risk factors which could lead to artery steal syndrome in preoperative,intraoperative and postoperative were analyzed between the two group to explore the high risk factors except to the factors that the diameter of the splenic artery or gastroduodenal artery and hepatic artery or the ratio of SA to hepatic artery (SA/HA) or the ratio of GDA to CHA (GDA/HA). Preoperative variables includes the portal hypertension,hypersplenism,the history of transcatheter arterial chemoembolization ,the volume of the spleen, warm ischemic time (WIT), cold ischemic time(CIT); Intraoperative variables includes operation time, anhepatic phase;Postoperative variables includes hepatic arterial mean velocity(HAV), hepatic arterial resistive index(HA-RI), portal venous mean velocity(PVV).From the April 2008,we ligated the splenic artery of the group that had artery steal phenomenon in liver transplantation ,this patients were regard as the group that ligation of splenic artery;the patients that had artery steal phenomenon before April 2008 were regard as the group that nonligation of splenic artery.To compare the incidence of ASS and the indexes of liver functions (TBIL,ALT,γ-GT) and indexs of graft blood flow(HAV,PVV,HA-RI) whin the first week after liver transplantation between the group that ligation of splenic artery and the group that nonligation of splenic artery.Results:1. The clinical datas of 181 patients were collected completely , 28 patients patients with ASS before OLT were identified before undergoing OLT(15.5%);27 patients had Splenic Artery Steal Phenomenon(96.4%),1patients had Gastroduodenal Artery Steal Phenomenon(3.6%), 25 patients were males ,3 patients were females.2. The mean diameter of portal vein and splenic vein are significantly wider in group with ASP than the group wih NASP .By means of univariate analysis between the group with ASP and group with NASP , The portal hypertension(P=0.001<0.01),hypersplenism(P=0.007<0.01),splenic volumes(P=0.012 <0.01),higher velocity of portal vein after operation(P <0.05),lower velocity of hepatic artery after operation(P <0.05)are significantly differcent.3.From the April 2008 to December 2009, 10 patients with ASP before undergoing OLT were all ligated splenic artery in liver transplantation,none had developed artery steal syndrome after operation.Before the time phase ,18 patients with ASS before OLT were detected before undergoing OLT in retrospect with whom 4 patients presented with artery steal syndrome(incidence 22.2% ),The incidence of ASS are significantly differcent between the two group(P=0.000<0.01).Moreover,the velocity of hepatic artery increase and the velocity of portal vein decrease in the group that ligation of splenic artery, which were significantly different than the group that nonligation of splenic artery;the indexs of graft liver function (TBIL,ALT,γ-GT) whin the first week after OLT are not different between the two group.Conclusions:1. Except to the risk that the diameter of the splenic artery or gastroduodenal artery and hepatic artery or the ratio of SA to hepatic artery (SA/HA)or the ratio of GDA to CHA (GDA/HA),The portal hypertension,hypersplenism,splenomegaly,higher velocity of portal vein,lower velocity of hepatic artery after liver transplantation are may be the high risk factors of ASS.2. The technology factor of arterial reconstuction were not except for the development of ASS.3. Ligation of splenic artery is a safety and convenient and effective procedure for preventing the development of steal syndromes after OLT, which could increase the volume of blood flow perminute of the hepatic artery.