Purpose: To identify factors affecting stent occlusion after stent placement in the portal vein in patients with malignant portal vein invasion.
Materials and methods: Forty patients were studied. Twenty-three patients had hepatocellular carcinoma, nine patients had pancreatic cancer, and eight patients had bile duct cancer. Stents were placed in the portal venous system across stenotic (n = 28) or obstructive (n = 12) lesions after percutaneous transhepatic portography. Bare stents were used in 33 patients and covered stents were used in seven patients. Twenty-two variables were analyzed with use of univariate and multivariate analyses to identify significant factors affecting stent occlusion.
Results: Stents remained patent during a mean follow-up period of 11.9 months (range, 2-61 mo) in 60% of the patients. Stent occlusion was found in 40% of the patients, with a mean period until occlusion of 3.7 months (range, 0.2-16 mo). In the univariate analysis, the following five factors were significantly associated with a higher probability of stent occlusion: (i) splanchnic vein involvement, (ii) Child-Pugh class C, (iii) obstruction of the portal venous system, (iv) pancreatic cancer, and (v) lack of anticancer treatment after stent placement. In the multivariate analysis, the first three factors were found to have independent value for stent occlusion.
Conclusions: Splanchnic vein involvement, severe hepatic dysfunction, and obstruction of the portal venous system are the most important factors affecting stent occlusion in patients with malignant portal vein invasion.