Objective To investigate the effective route and proper method in transfecting gene into liver graft mediated by adeno-associated virus vector.Methods Three routes including hepatic artery,portal vein and hepatic artery+portal vein,and 3 methods,i.e.routine,circulation and clamping were employed for infusion.The best infusion route and method of gene transfection into liver graft were determined by observing the color change of liver and detecting liver function and transfoetion rate of liver cells.The safety of these methods was evaluated.Results In all the infusion procedures,the color of the liver grafts turned from red to white,no apparent color differenee of the livers and no enlargement nor mottling were observed under surgical microscope.The liver color was back to normal immediately after blood flow was restored.No significantly statistical differences of the ALT values were observed among all the groups(F=0.343,1.265,0.055,P＞0.05).Adeno-associated virus vectors coding for the enhanced green fluorescence protein(AAV2-EGFP)were successfully transfected into liver cells by the 3 infusion routes 1 week later,and the difierences of transfection rates via the 3 routes had no statistical significance(F=0.080,0.091,0.045,P＞0.05).The transfoction rate of AAV2-EGFP was the highest at any time points when using the clamping method,and then followed by circulation method and routine method,with statistical differenee(F=3.880,2.976,5.129,P＜0.05).The transfection rates of AAV2-EGFP were increased progressively and peaked at the 6th week,and then they were decreased gradually.Conclusions Infusion via hepatic artery is the effective route for gene transfection and clamping the vessels can elevate the transfection rate of AAV2-EGFP.All procedures were performed without detectable liver injury.The transfection of gene into liver graft mediated by adeno-associated virus vector is a slow and persistent process.

Objective To preliminarily evaluate the application value of SpyGlass direct visualization system in the diagnosis and treatment of biliary stricture after liver transplantation. Methods Clinical data of 4 patients presenting with biliary stricture after liver transplantation who underwent SpyGlass direct visualization system examination were collected. The examination, treatment and prognosis of biliary stricture were analyzed. Results The examination results of color Doppler ultrasound, magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) in 4 patients suggested biliary anastomotic stricture with intrahepatic biliary dilatation, and 2 of them were complicated with intrahepatic biliary calculi. Repeated placement of biliary stent under ERCP yielded poor effect in 3 cases. SpyGlass direct visualization system examination hinted biliary anastomotic stricture in 4 patients, 3 cases of intrahepatic biliary dilatation, 3 cases of intrahepatic biliary calculi, 2 cases of purulent bile and 3 cases of floccules within the biliary tract, 1 case of congestion and edema of biliary tract wall and 2 cases of local epithelial necrosis and stiffness changes of intrahepatic biliary tract wall. The wire could not be inserted in 1 patient due to severe biliary anastomotic stricture. Four patients were treated with biliary stricture resection + biliary stone removal + biliary end-to-end anastomosis, biliary stricture resection + biliary-intestinal anastomosis, ERCP lithotomy + biliary metal stent implantation, and biliary metal stent implantation + percutaneous transhepatic bile duct lithotomy, respectively. Relevant symptoms were relieved without evident complications. All patients survived during the follow-up until the submission date. Conclusions Compared with traditional imaging examination, SpyGlass direct visualization system may more directly display the morphological characteristics of biliary tract wall and structural changes within biliary tract cavity, which is an effective examination tool for biliary stricture after liver transplantation. In addition, individualized treatment methods may be adopted for different biliary tract diseases, which is expected to improve clinical prognosis of patients.