Transjugular Intrahepatic Portosystemic Shunt With Covered Stents Of Different Diameter For The Prevention Of Esophageal Variceal Rebleeding:A Randomized Controlled Trial

?Background? Transjugular intrahepatic portosystemic shunt(TIPS)is a critical treatment modality for gastroesophageal variceal bleeding and remains the major option for the secondary prophylaxis of variceal rebleeding.However,hepatic encephalopathy(HE),one of the major post-procedural complications of TIPS,influences patient's quality of life and long-term prognosis.Currently,two different diameters are available for stents used in TIPS,i.e.,8mm and 10 mm.It has long been conceived that the effectiveness of portal decompression can be improved as the diameter of the shunt increases,yet the incidence of HE would correspondingly increase,and vice versa.Therefore,the selection of stent diameter in TIPS procedure remains an open issue ever since its first introduction into clinical application in almost three decades ago,and recommendations in current guidelines are lacking.In 2010,a randomized controlled trial comparing the use of 8mm and 10 mm covered stents suggested that the incidence of shunt dysfunction was significantly higher in 8mm stents group,while the incidence of HE did not decrease.However,the credibility of this study was limited by its undersize study population and its conclusions are thereby controversial.In contrast,another recent study indicated that the 2-year incidence of HE was only 18% in patients receiving TIPS with 8mm stents,a value which was obviously lower than that with 10 mm stents in previous studies,whereas shunt dysfunction rate did not increase.?Aims? The current randomized controlled trial was designed and launched for the purpose of comparing TIPS with 8mm and 10 mm covered stents in the prevention of variceal bleeding for the purpose of investigating whether 8mm stents would reduce the occurrence of HE and alleviate liver function deterioration without compromising shunt function.?Methods? 1)Patients with esophageal variceal bleeding were prospectively included in the study after screening for eligibility and informed consent was obtaned.TIPS with either 8mm or 10 mm covered stents was then performed within 24–48 hours after randomization.2)The primary endpoint is shunt dysfunction,whereas the secondary endpoints included rebleeding,hepatic encephalopathy,survival,composite endpoint of rebleeding and all-cause death,and liver function after the procedure.3)Clinical event information collection as well as imaging and laboratory examinations was performed at baseline,during the procedure,and at 1 month,3 months,6 months after the procedure and every 6 months thereafter.4)Independent sample t test or paired-sample t tests were performed to compare continuous variables at baseline,whereas Fisher's exact and Mann-Whitney U tests were performed to compare categorical variables at baseline.5)Survival curves was generated with Kaplan-Meier method and was compared with log-rank tests for time-to-event analysis in terms of shunt dysfunction,rebleeding,HE,and mortality.Competing risk analyses taking death or liver transplantation as competing event were performed for shunt dysfunction,rebleeding and HE,factors with imbalanced distribution between groups was taken as covariates for adjusting survival analysis.6)Prognostic factors of clinical events were identified with Cox regression analysis,whereas Logistic regression was applied for dichotomies.?Results? 1)All baseline characteristics except age was comparable in 8mm and 10 mm groups.2)The absolute value and the percentage of decrease in portosystemic pressure gradient was not significantly different in 8mm and 10 mm groups.3)In terms of the primary endpoint,the incidence shunt dysfunction was not significantly different in 8mm and 10 mm groups.4)Regarding the secondary endpoint,rebleeding rate and survival did not differ between the two groups.Although the incidence of overt HE in 8mm group was not significantly different from that of 10 mm group,the cumulative incidence of spontaneous overt HE was significantly lower in 8mm group,and rates of severe HE as well as refractory HE were also significantly lower.5)Competing risk analyses and survival analyses showed consistent results.6)Results of liver function tests and liver function scores significantly favored 8mm group.?Conclusions? 1)The use of 8mm stents in TIPS may not increase the incidence of shunt dysfunction.2)TIPS with 8mm stents could significantly reduce the incidence of spontaneous overt HE,severe HE and refractory HE without compromising the effectiveness in preventing variceal rebleeding.3)Therefore,8mm stents should be favored in TIPS for the prevention of variceal rebleeding.