Abstract: Objective To study the effect of early application of low molecular weight heparin on the formation of portal vein thrombosis（PVST） in patients with liver cirrhosis after laparoscopic splenectomy and esophagogastric devascularization（LSED）.Methods 112 patients with liver cirrhosis and portal hypertension （PHT） were admitted to our hospital from March 2014 to June 2015. All patients were treated with LSED. The patients were divided into two groups according to the order of admission，with 56 in each group. Among them，56 patients were treated as control group，and 56 patients were treated with low molecular weight heparin as the observation group. The two groups of patients were followed-up for two weeks. Serum liver function tests， portal vein blood flow，blood coagulation function，PVST occurrence and complications were observed in the two groups.Results Before and after treatment，serum TBIL，ALB and INR levels in the two groups were not significantly different（P>0.05）；Before treatment，there was no significant difference in the maximum blood flow velocity，mean blood flow velocity and portal vein diameters between the two groups （P>0.05）；After treatment，the maximum blood flow velocity，mean blood flow velocity and portal vein diameter in the observation group were （20.83±1.15）cm/s，（15.12±1.19） cm/s，and （15.86±3.12） mm，much higher than （14.36±0.74） cm/s，（10.28±0.71） cm/s，and （14.27±2.96）mm，respectively，in the control group （P<0.05）；after treatment the APTT，Pt，FIB and TT in the observation group were（25.72±3.64） s，（14.96 ±2.26） s，（3.51±0.86） g/L，and （20.11±3.65） s，much longer than those in the control group，[（23.37±3.52） s，（13.87±2.14） s，（2.62±0.73） g/L，and（18.14±3.23） s，respectively，all P<0.05]；The incidences of PVST in the observation group and in the control group were 7.14% and 42.86%，respectively，and the difference was significantly （P<0.05）；the incidence of other complications in the observation group and in the control group were not significantly different （P>0.05）.Conclusion Early application of low molecular weight heparin for the prevention of PVST after LSED postoperatively has a good effect， which might effectively improve the coagulation function and safe in clinical practice.

Key words: Liver cirrhosis, Laparoscopic splenectomy and esophagogastric devascularization, Low molecular weight heparin, Portal vein thrombosis