Objective To establish an anatomical classification of chronic portal vein thrombosis (PVT) in order to guide the transjugular intrahepatic portasystemic shunt (TIPS) manipulation, and to analyze the correlation between anatomical classification of PVT and the occurrence of hepatic encephalopathy (HE) after TIPS. Methods During the period from June 2010 to June 2013 at authors’ hospital, TIPS with fluency covered stent was carried out in a total of 73 patients with chronic portal vein thrombosis. Based on the location of portal vein thrombosis, the anatomical classification of portal vein thrombosis (PVT-type) was initially established. The changes in portal vein pressure after TIPS were evaluated. The occurrence of HE at 15 days and at 3 and 6 months after TIPS in patients with different PVT-type was statistically analyzed. As the understanding of 0-phase minimal hepatic encephalopathy (MHE) was deepened, the authors added a subdivision to the 0-phase, including normal cognitive function state and minimal hepatic encephalopathy (MHE) into West - Haven grading to further precisely assess the hepatic encephalopathy. Using paired samples t-test, the changes of portal vein pressure after TIPS were evaluated. The grading of hepatic encephalopathy and the number of occurrence after TIPS were particularly recorded, the results were compared between groups at the same time and between the types at different times. Results The preoperative and postoperative portal vein pressure in type Ⅰ patients receiving TIPS therapy was (42.7 ± 9.6) and (35.0 ± 6.7) cm H2O respectively, the difference was statistically significant (t = 7.61, P <0.01);in typeⅡpatients it was(39.8 ± 5.5) and(31.0 ± 5.7) cm H2O respectively(t=17.2, P<0.01);in type Ⅲpatients it was (43.2 ± 5.8) and (32.4 ± 5.0) cm H2O respectively (t = 25.0, P < 0.01); and in type Ⅳpatients it was (43.0 ± 3.7) and (36.6 ± 6.6) cm H2O respectively (t = 4.26, P <0.01). The occurrence of HE 15 days after TIPS was mainly seen in patients with type Ⅳ , Ⅰ and Ⅲb. Phase Ⅰ hepatic encephalopathy mainly occurred in patients with PVT-type Ⅱa, Ⅲb and type Ⅰ. Phase Ⅱ hepatic encephalopathy occurred mainly in patients with PVT-type Ⅱb, Ⅲb and type Ⅰ. Three months after TIPS, the occurrence of MHE was mainly seen in patients of Ⅲa, Ⅱa and Ⅱc type. Phase Ⅰ hepatic encephalopathy mainly occurred in patients with Ⅲa, Ⅱb and Ⅳ type. Phase Ⅱ hepatic encephalopathy occurred mainly in patients with PVT-typeⅡa,Ⅱb andⅢb. Six months after TIPS, the occurrence of MHE was mainly seen in patients of type Ⅱa, Ⅱc and Ⅲb. Phase Ⅰ hepatic encephalopathy mainly occurred in patients with type Ⅱb, Ⅰ and Ⅲb. Phase Ⅱ hepatic encephalopathy occurred mainly in patients with typeⅡb,Ⅲb andⅠ. The HE condition lasted for longer time in patients withⅡb,Ⅲb andⅠtype. Conclusion The establishment of a rational anatomical classification for chronic portal vein thrombosis can effectively guide the clinical application of TIPS. The occurrence of postoperative hepatic encephalopathy is higher in patients with pure main portal vein thrombosis or superior mesenteric vein thrombosis.

30%) might be a risk factor in HAPE susceptibility.