Percutaneous Transhepatic Biliary Stenting with Uncovered Self-Expandable Metallic Stents in Patients with Malignant Biliary Obstruction - Efficacy and Survival Analysis.

Background: The aim of this study was to assess short- and long-term outcomes of malignant biliary obstruction (MBO) treatment by percutaneous transhepatic biliary stenting (PTBS) with uncovered selfexpandable metallic stents (SEMS), and to identify predictors of survival.

Material/methods: A nine-year, single-centre study from a prospectively collected database included 222 patients with inoperable MBO treated by PTBS with uncovered nitinol SEMS.

Results: Technical and clinical success rates were 95.9% and 82.4%, respectively. The total rate of postprocedural complications was 14.4%. The mean durations of the primary and secondary stent patency were 114.7±15.1 and 146.4±21.2 days, respectively. The 30-day mortality rate was 15.3% with no procedure-related deaths. The mean estimated length of survival was 143.3±20.6 days. Independent predictors increasing the risk of death included higher than 115 μmol/L serum bilirubin 2-5 days after biliary stenting (HR 3.274, =0.019), distal (non-hilar) obstruction of the bile ducts (HR 3.711, =0.008), Bismuth-Corlette type IV stricture (HR 2.082, =0.008), obstruction due to gallbladder cancer (HR 31.029, =0.012) and only partial drainage of liver parenchyma (HR 4.158, =0.040).

Conclusions: PTBS with uncovered SEMS is an effective and safe method for palliative treatment of MBO. Serum bilirubin higher than 115 μmol/L 2-5 days after the procedure has a significant negative impact on patients' survival. Lower survival is also determined by distal bile duct obstruction, Bismuth- Corlette type IV stricture, biliary obstruction caused by gallbladder cancer and when only partial liver drainage is applied.