Transjugular Intrahepatic Portosystemic Shunt: Evaluation of the Impact of the Stent’s Configuration on the Patency Rate

PURPOSE: To evaluate the impact of the configuration of the stent on the patency rate after transjugular intrahepatic portosystemic shunt with a self-expanding stent. MATERIALS AND METHODS: In total, 80 patients (60 male, 20 female; mean age 56 ± 9.6, range 37 - 81) with a transjugular intrahepatic portosystemic shunt were evaluated. The primary technical success rate, interventional revision rate, and mean patency rate according to Kaplan-Meier were calculated. The angle of deviation of the blood flow at the portal venous inflow and central venous outflow were measured on projected angiograms (valid cases, n = 78). The following five angle groups were established: 1. portal venous inflow, 2. central venous outflow, 3. maximum, angle, 4. minimum angle, and 5. sum of both angles in the shunt system. Within each group, the Mann-Whitney Test and after dichotomic partition using the median Pearson’s Chi-Square Test and Fisher’s Exact Test were carried out to prove the dependency of the patency on the stent’s configuration. RESULTS: The primary technical success rate was 93 %, the interventional revision rate was 28 %, and the mean patency rate was 17.5 months. The mean/standard deviation/median angle were as follows: 1. portal venous inflow 66.5°/ 19.2°/ 65°, 2. central venous outflow 43.7°/ 14.0°/ 40°, 3. maximum angle 69.1°/ 16.3°/ 65°, 4. minimum angle 40.6°/ 13.3°/ 40°, and 5. sum of both angles 110.2°/ 21.8°/ 110°. The 2-sided values of significance in the Mann-Whitney Test/Chi-Square Test/Exact-Fisher Test were as follows: 1. portal venous inflow 0.112 / 0.066 / 0.083, 2. central venous outflow 0.960 / 0.919 / 1.000, 3. maximum angle 0.151 / 0.042 / 0.056, 4. minimum angle 0.578 / 0.622 / 0.632, and 5. sum of both angles 0.104 / 0.111 / 0.140. CONCLUSION: The shunt’s patency rate when using a self-expanding stent is not dependent on the stent’s configuration regarding the deviation of the blood flow at the portal venous inflow and central venous outflow, and the maximum, minimum and total deviation in the shunt.