Replacing plastic with metallic stents in malignant extrahepatic biliary obstruction: Risk factors surrounding early biliary metallic stent dysfunction.

Background: Patients diagnosed with extrahepatic malignant biliary obstruction (MBO) often initially undergo endoscopic retrograde biliary drainage with a plastic stent (PS). Self-expandable metallic stents (SEMSs) have been shown to yield better outcomes than PS. This study aimed to identify predictors of early SEMS dysfunction in MBO patients who initially received PS and later changed to SEMS.

Methods: We retrospectively analyzed patients who received their first SEMS insertion to replace an existing PS for distal extrahepatic MBO between January 2015 and December 2021. We also analyzed the possible risk factors for early SEMS dysfunction (<90 days).

Results: Fifty-six patients who received their first SEMS for distal extrahepatic MBO were identified. The rate of early SEMS dysfunction was 30.1%. The main causes of early SEMS dysfunction were non-specific cholangitis (35.3%) and stent clogging (35.3%). Multivariate logistic regression analysis identified two independent predictors of early SEMS dysfunction: (a) a history of a short PS patency (less than 60 days), and (b) post-endoscopic retrograde cholangiopancreatography (ERCP) cholangitis following SEMS placement. The odds ratio [OR] for (a) was 10.77; 95% confidence interval [CI] 2.54-45.66, p = 0.001, and for (b) [OR] 6.59 [CI] 1.00-43.43, p = 0.050.

Conclusions: Two risk factors associated with early SEMS dysfunction in patients with extrahepatic MBO are a short PS patency (<60 days) prior to SEMS insertion and the development of post-ERCP cholangitis following SEMS placement.