Outcome of self-expandable metallic stents in low-grade versus advanced hilar obstruction.

Background: Self-expandable metallic stents (SEMS) are known to provide a longer patency time than plastic stents for malignant biliary obstructions including hilar obstruction. However, studies that focus on the efficacy of SEMS in low-grade and advanced hilar obstructions are still scanty.
Methods: Ninety four patients with malignant hilar obstructions were enrolled (six were later excluded). Patients were divided into two groups according to their Bismuth levels. Group A were patients with Bismuth I (n = 53). Group B were patients with Bismuth II, III and IV (n = 35). Technical success, complications, jaundice resolution, stent patency time, and patients' survival were analyzed.
Results: Our intention-to-treat analysis showed that group A had a significant lower rate of post-endoscopic retrograde cholangiopancreatography (ERCP) cholangitis than group B; 16.1% versus 44.7%, (P < 0.01). Four patients from group B still had persistent jaundice. Our per protocol analysis demonstrated that median stent patency time in groups A and B were not statistically different (74 vs 60 days). Median survival time in groups A and B were also not statistically different (90 vs 75 days). In both groups, those without liver metastasis had significantly better patency and survival time than those with liver metastasis (P = 0.010 and 0.027, respectively).
Conclusions: In patients with hilar obstruction, liver metastasis is one of the main factors that determine survival of the patient. Patency times of SEMS in both low-grade and advanced obstructions are comparable. However, in the advanced group, there is a significant risk of post-ERCP cholangitis.