METARSI Trial: Endoscopy International Open, Feb.26

The METARSI trial is a prospective, multicenter randomised controlled study comparing partially covered self-expanding metal stents (PC-SEMS) versus uncovered SEMS (U-SEMS) in patients with malignant unresectable distal biliary obstruction (DBO) undergoing ERCP.

A total of 261 patients were randomised (130 PC-SEMS, 131 U-SEMS) with a 12-month follow-up. Most strictures were secondary to pancreatic adenocarcinoma (75%), and nearly half had metastatic disease.

Key findings:

Stent dysfunction rates were similar between groups (11% PC-SEMS vs 14% U-SEMS; P = 0.70).

Overall survival did not differ significantly (median ~108 vs 100 days).

Kaplan–Meier analysis showed comparable stent patency.

A non-significant trend toward more procedure-related complications was observed in the partially covered group (2% vs 7%).

Clinical Interpretation:

There was no clear superiority of partially covered stents over uncovered stents in terms of dysfunction, survival, or patency. Given similar outcomes and potential migration risks associated with covered designs, stent selection should remain individualised based on anatomy, tumour characteristics, and operator experience.

Takeaway:

In malignant distal biliary obstruction, both PC-SEMS and U-SEMS perform comparably—routine preference for partially covered stents is not supported by this randomised evidence.