Soft surface irregularity of malignant perihilar biliary strictures in cholangiography as a risk factor for early dysfunction of multiple metal stents

Abstract

Background: Multiple metal stents (multi-MS) in the perihilar bile duct often develop dysfunction in an unexpectedly short period.

Aims: This study is aimed to identify the risk factors for shorter patency of multi-MS.

Methods: Of 97 patients who underwent multi-MS placement, 68 patients were followed-up for >28 days were retrospectively analyzed. Univariate analyses with the log-rank test was performed on 20 factors, including two newly defined classifications of cholangiography: the R classification, which classifies the rough image (localized type [R1] or spreading type [R2]); and the S classification, which classifies the surface texture (soft irregularity [S1], solid irregularity [S2], or smooth [S3]).

Results: Stent dysfunction occurred in 36 patients (53%) (median time, 209 days). Type S1 was a significant risk factor for short stent patency (median, 100 days in S1 [n=18]; 231 in S2 [n=38]; 356 in S3 [n=12], p<0.0001). On multivariate analysis, type S1 was again the only independent factor among the six factors (HR 4.8, p<0.001).

Conclusion: Soft surface irregularity of the perihilar malignancy in cholangiography was found to be a significant risk factor for a shorter time to dysfunction of multi-MS.

Keywords: Cholangiocarcinoma; Classification; Hilar; Klatskin tumor; Obstruction; Risk factor.