A Research Of Transjugular Intrahepatic Portosystemic Shunt For Portal Venous Hypertension And Cavernous Transformation Of Portal Vein

Portal venous hypertension is one of common complications of decompensated liver cirrhosis.At the stage of cirrhosis,the resistance of blood flow and blood amount of tributaries of portal venous system increases,which is the immediate cause of portal venous hypertension.The etiological background of liver cirrhosis is quite different between China and western countries,that the alcoholic liver disease is the most prevalent pathogenesis of western countries while virus hepatitis,especially hepatitis B,accounts for the majority of cirrhosis in China.An epidemiological data revealed the patients with active stage of chronic virus hepatitis B are about 20million in China and among them 20-45%patients were died of cirrhotic complications including portal hypertension and liver cancer.If appropriate therapeutics are not performed,the portal venous hypertension bring about many severe complications,such as variceal haemorrhage,intractable ascites,portal venous thrombosis and even hepatocellular carcinoma.A foreseeable fact is the quality of life of these patients heavily deteriorate and the hygienic economic burden increases a lot.It is an intractable work for clinicians to reduce the portal venous hypertension of patients.Among various therapeutic methods,transjugular intrahepatic portosystemic shunt?TIPS?,which establish an artificial shunt between portal vein and hepatic vein with multiple interventional radiological techniques,is a minimally invasive procedure to decrease the portal venous hypertension and its complications with the same efficacy to bypass surgery.95%or more patients with variceal bleeding can achieve instant hemostasis with TIPS.However,TIPS also has side effect and complications,for instance liver injury,hepatic encephalopathy,shunt dysfunction and so on.Post-procedural shunt dysfunction decreases a lot with the application of covered stents or grafts.Guidelines issued by FDA,EASL and Chinese Liver Disease Association recommend the routine application of covered stents for TIPS.Viatorr stent is one of dedicated stents for TIPS,which has been licenced since October of2015.Before that,Fluency cover stent with bare stent overlapped insertion was the most common strategy for TIPS.Clinical data of application of Viatorr stent in China is still rare.Post-procedural hepatic encephalopathy occurs in 15-48%of patients who undergo TIPS.With the improve of techniques and prevention,the incidence of that decreases than before.The way to minimize and prevent hepatic encephalopathy is research focus of TIPS.Cavernous transformation of portal vein?CTPV?is a sort of disease that caused by portal venous hypertention induced by establish of collateral veins resulting from obstruction of main trunk or branches of portal vein.The collateral veins are morphologically similar to cavernous hemangioma.Insidous or untreated portal venous thrombosis,and with thrombus organization,a plenty of collateral veins form across the first hepatic porta to restore the bloodflow of portal vein and attenuate the venous hypertension,which is the main cause of CTPV.However,the collateral veins cannot compensate the original portal vein because of the pathophysiological differences and tributaries of portal venous system.Variceal haemorrhage is one of common complications of CTPV that severely endanger patients.However,no effective medication can attenuate portal venous hypertension of CTPV currently.Moreover,the difficulty of bypass surgery and liver transplantation is much higher than patients without CTPV but the prognosis of bypass surgery or liver transplatation are not satisfied,because of collateral veins across hepatic porta.Meso-Rex bypass has been widely deemed as curative surgery to treat CTPV recently.But difficult techniques,that left branch of portal vein must be isolated from Rex crypt and anastomosed carefully,which require highly experienced hand and highly selected patients,impeded its widely application.Once upon a time the CTPV was considered one of absolute contraindications of TIPS.With the improvement of techniques and progression of imaging method,a few researchers have undertaken managing CTPV by TIPS.The outcome of CTPV is preferred with TIPS,though these evidence comes from small series.Mid to long term follow-up is needed to verify the accurate effectiveness.Therefore,more comprehensive research must be undertaken to evaluate the effect and risk factors of TIPS in the management of CTPV to overcome the intractable and fatal gastric bleeding to supply valid evidence for clinical strategy.Part one A research of TIPS for cirrhosis induced portal venous hypertension1.Analysis of blood ammonia and blood perfusion in different tributaries of hepatic portal vein.Purpose Prospectively analyze different concentration of serum ammonia in the tributaries and main trunk of portal venous system and haemodynamic characters of left and right branch of hepatic portal vein with perfusion imaging by DynaCT.Methods and materials blood samples of peripheral vein,superior mesenteric vein,splenic vein,left and right branch of hepatic portal vein of 30 consecutive patients with liver cirrhosis are collected to perform blood ammonia assay during TIPS procedure.Perfusion image of liver is acquisited by cannulation in superior mesenteric vein and splenic vein and amount of blood flow and peak times of contrast agent are calculated at Syngo Workplace.Results the concentrations of blood ammonia in peripheral vein,superior mesenteric vein,splenic vein,left and right branch of hepatic portal vein are 49.5�12.1 mol/L,155.7�49.2 mol/L,53.8�19.4mol/L,84.2�33.6 mol/L and 108.2�36.6 mol/L,respectively.The blood perfusion parameters of left branch and right branch of hepatic portal vein are 5.89�1.53ml/100g vs.9.04�2.18 ml/100g in the SMV-portal venous perfusion image and8.76�2.30 ml/100g and 4.07�1.39 ml/100g in the the PV-portal venous perfusion image.Conclusions The tributaries of hepatic portal vein have different concentration of blood ammonia and the haemodynamic characters are different between left and right branch of hepatic portal vein.2.Effect of left branch shunt and right branch shunt of TIPS.Purpose Evaluate the clinical effect of left branch shunt and right brunch shunt.Methods and materials Clinical data of 67 cases of left branch shunt and 31 cases of right brunch shunt are collected and retrospectively analyzed.The reduction of portal venous pressure,survival rate,rebleeding rate,shunt dysfunction rate and hepatic encephalopathy rate were compared between left branch shunt and right branch shunt.Outcomes The dysfunction rate was 11.9%in cases of left branch shunt and 29.0%in cases of right branch shunt?p=0.048?.Hepatic encephalopathy rate was 20.9%in cases of left branch shunt and 41.9%in cases of right branch shunt?p=0.029?.Post-procedural reduction of HVPG was 21.4�6.0cm H₂O in left branch shunt cases and18.9�7.4 cmH₂O in right branch shunt cases?p>0.05?.Survival rate was 85.1%in left branch shunt cases and 83.9%in right branch shunt cases?p>0.05?.Rebleeding rate was 13.4%in left branch shunt cases and 12.9%in right branch shunt cases?p>0.05?.Conclusions The survival rate,rebleeding rate,and reduction of HPVG have no difference between left branch shunt and right branch shunt.But the shunt dysfunction rate and procedure-related hepatic encephalopathy rate are higher in the right branch shunt cases.3.Comparison of effect of Viatorr stent and imitated Viatorr stent in the application of TIPSPurpose Evaluate the effect of Viatorr stent and imitated Viatorr stent of TIPS.Methods and materials Clinical data of consecutive 35 cases of Viatorr stent and 49cases of imitated Viatorr stent were collected for post-hoc analysis.The 6 month and1 yearadverse events,including post-procedural portal venous pressure,shunt patency rate,hepatic encephalopathy rate,rebleeding rate and survival rate are analyzed.Results The 6 month primary patent rate of Viatorr stent and imitated Viatorr stent were 91.43%?32/35?and 91.83%?45/49?,respectively.The 1 year primary patent rate of Viatorr stent and imitated Viatorr stent are 85.71%?30/35?and83.67%?41/49??p=0.943?,respectively.However,the differences are both not statistically significant.The adjusted secondaty patent rate were both 100%.The 1year overall hepatic encephalopathy rate are 28.57%?10/35?and 26.53%?13/49?,respectively,without significant statistical difference?p=0.913?.The 1 year survival rate are 85.71%?30/35?and 83.67%?42/49?,respectively,without significant statistical difference?p=0.0.894?.The rebleeding rate of two groups are 11.43%?4/35?and 14.29%?7/49?,respectively,without significant statistical difference?p=0.903?.The reduction of hepatic venous pressure gradient post-procedurally between two groups are 24.3�2.4 cmH₂O and 22.7�3.1 cmH₂O,respectively without significant statistical difference?p=0.874?.Conclusions No difference occurs in the 1 year patent rate,hepatic encephalopathy rate,rebleeding rate and post-procedural reduction of hepatic venous pressure gradient between Viatorr stent group and imitated Viatorr stent group.Part two Clinical effect of TIPS in CTPVPurpose Detect the risk factor and evaluate the effect of TIPS in patients with CTPV.Methods and materials From May of 2012 to June of 2017,the clinical data of23 consecutive patients admitted to hospital of the First Affiliated Hospital of Zhengzhou University with portal venous thromboembolization complicated by CTPV was collected for retrospective analysis.The post-procedural portal venous pressure change,patent rate of hepatic shunt,hepatic encephalopathy rate,rebleeding rate was analyzed.And risk factor of events was analyzed by Logistic regression.Outcomes The technically success achieved in 73.91%?17/23?patients with CTPV.Among them,the technically success rate is 66.72%?12/18?in the subgroup of patients with complete obstruction of hepatic vein and that rate is 100%in 5 patients with incomplete obstruction of hepatic portal vein.In the 23 cases of TIPS,4 cases were undergone conventional TIPS,13 cases were percutaneous transhepatic puncture-assisted.Shunts of 5 cases were inserted in left branch of hepatic portal vein,4 cases were in right branch of hepatic portal vein,5 cases were in main trunk of hepatic portal vein and 3 cases are in collateral vein.During follow-up,2 cases of rebleeding occurred in patients who undergone successful TIPS and 3 cases of rebleeding occurred in patients who failed TIPS.4 cases developed shunt dysfunction.3 patients died in the subgroup of patients who undergone successful TIPS and 2patients died and 1 patient was lost to follow-up in the subgroup of patients who failed TIPS.Among the patients who undergone successful TIPS,3 cases were complicated by post-procedural hepatic encephalopathy and among the patients who failed TIPS,2 cases were complicated by hepatic encephalopathy.The patients recovered with ammonia clearance medication.No hepatic myelopathy occurred in the series.Conclusions TIPS is a safe and flexible method to treat patients with CTPV with satisfied early effect.For the patients who failed to achieve shunt across main trunk of hepatic portal vein,the shunt across in the collateral veins is an effect alternative strategy.