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

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.

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.

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).

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.