Introduction
Stent placement by endoscopic retrograde cholangiopancreatography (ERCP) is one of the preferred methods for biliary drainage in unresectable malignant biliary obstruction. Nevertheless, clinical success of palliative drainage is not easy to predict, especially at the time of ERCP.
Aims & Methods
We conducted a multicentre retrospective cohort study in 3 centres in Portugal, involving patients with unresectable malignant biliary obstruction (UMBO) submitted to palliative ERCP-guided biliary stenting between 2015 and 2022. This study aimed to evaluate clinical success of biliary drainage in our population, as well as to evaluate the performance of two recently developed and internally validated risk scores for predicting successful biliary drainage after ERCP-guided endobiliary stenting in UMBO, created by the group of Pausawasdi N. et al. This group developed a first score for predicting early clinical success of biliary drainage (decrease ≥50% in total bilirubin (TB) levels within 2 weeks after stenting), using as variables the presence/absence of extrahepatic biliary obstruction, peritoneal carcinomatosis, the type of biliary stent (plastic or metallic) and pre-endoscopic alkaline phosphatase level. The second score was developed to predict complete clinical success of biliary drainage (normalization of TB levels within 6 weeks after stenting) including pre-endoscopic TB levels, presence/absence of extrahepatic biliary obstruction and type of stent as variables. We included 217 patients for this study. However, due to the limitations of a retrospective analysis, we could not evaluate the performance of these scores for all the patients of our cohort. Statistical analysis was performed using SPSS v.29.
Results
In our cohort, a decrease in total bilirubin (TB) levels ≥50% within 2 weeks after biliary stenting was reached in 81.9%(N=113) of the patients of a subpopulation of 138 patients in which these TB levels were available. TB normalization in 6 weeks after stenting occurred in 55%(N=72) of the cases from a subpopulation of 131 patients in which this TB level was measured. In our population, the predictive scores for early and complete clinical success had an AUROC of 0.597 (95% CI, 0.471-0.723; p = 0.13) and of 0.737 (95% CI, 0.650-0.825; p <0.001), respectively.
Conclusion
In our cohort, the predictive score for complete clinical success of biliary stenting in UMBO (at 6 weeks) had a good accuracy (AUROC 0.74), similar to the AUROC reported by this study group (AUROC 0.76 in the validation cohort). The main advantage of this score relies on the fact that it can be applied before ERCP, since its variables can all be determined pre-endoscopically or, at the most, by the time of ERCP (type of stent), possibly allowing the definition of a better strategy for the management and follow-up of these patients.
References
Pausawasdi, N., Termsinsuk, P., Charatcharoenwitthaya, P., Limsrivilai, J., & Kaosombatwattana, U. (2022). Development and validation of a risk score for predicting clinical success after endobiliary stenting for malignant biliary obstruction. PloS one, 17(8), e0272918. https://doi.org/10.1371/journal.pone.0272918