Evaluation of Self-Expandable Metallic Stent Characteristics Associated with Longer Patency in Patients with...

Various self-expandable metallic stents (SEMS) have been developed to improve the patency of patients with malignant distal biliary obstruction (MDBO). This retrospective study aimed to evaluate SEMS characteristics associated with longer patency in initial SEMS placement for unresectable MDBO.

Patients with unresectable MDBO identified in databases from four medical centers were analyzed. Patient background, SEMS type, and time to recurrent biliary obstruction (TRBO) were analyzed. The extracted variables were subjected to propensity score matching (PSM) to reduce selection bias.

Between 2010 and 2025, 780 patients with MDBO were identified, 501 of whom met the inclusion criteria. In the multivariate analysis, 12-mm bore size, laser-cut SEMS, and 8-cm length SEMS were identified as independent significant factors contributing to TRBO. To confirm the utility of three significant factors, PSM analysis was performed on each. A total of 126 patients with 12- and 10-mm bore-size SEMS, 34 patients with laser-cut and braided SEMS, and 169 patients with 8-cm and < 8-cm length SEMS were compared. The hazard ratio of the 12-mm bore size SEMS was 0.65 (95% CI 0.44-0.98, P = 0.037), laser-cut SEMS was 0.24 (95% CI 0.07-0.86, P = 0.029), and SEMS < 8-cm length was 0.68 (95% CI 0.47-0.99, P = 0.044). The stent occlusion rate was lower in the 12-mm SEMS group (16%) than in the 10-mm SEMS group (26%). No stent migration was observed in laser-cut SEMS.

Because the choice of SEMS length depends on the patient's condition, a 12-mm bore size and laser-cut SEMS seem promising for SEMS selection.

ClinicalTrials.gov UMIN000058935.