Hepatobiliary scintigraphy of bile excretion after endoscopic ultrasound-guided hepaticogastrostomy for malignant biliary obstruction: a retrospective study in Japan

Background/Aims: Hepatobiliary scintigraphy (HBS) is used to evaluate bile excretion. This study aimed to evaluate biliary excretion during endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) using HBS. Methods: We retrospectively evaluated 78 consecutive patients with malignant extrahepatic biliary obstruction, who underwent HBS after EUS-HGS between April 2015 and July 2022. The peak time and decay rate were scored with 0, 1, or 2 points based on thresholds of 20 and 35 minutes, and 10% and 50%, respectively. A total score of 4 or 3 was considered indicative of good bile excretion, whereas scores of 2, 1, or 0 indicated poor bile excretion. Results: The good and poor bile excretion groups included 40 and 38 cases, respectively. The group with good bile excretion had a significantly longer time to recurrent biliary obstruction compared to the poor bile excretion group (not reached vs. 124 days, p =0.026). Multivariate analysis identified the site of obstruction as a significant factor influencing good bile excretion (odds ratio, 3.39; 95% confidence interval, 1.01-11.4, p =0.049), with superior bile excretion observed in cases involving upper biliary obstruction compared to middle or lower biliary obstruction. Conclusions: In patients with malignant biliary obstruction who underwent HGS, the site of obstruction is significantly associated with stent patency.