Diagnostic Efficacy and Spatial Factors of Percutaneous Transhepatic Cholangiobiopsy in Malignant Biliary Obstruction: A Comparative Analysis of Hilar Versus Distal Obstruction

Background: The aim of this study was to explore the clinical application value of percutaneous transhepatic biliary drainage (PTCD) combined with intraductal forceps biopsy in the diagnosis of malignant biliary obstruction (MBO) and to analyze the mechanisms by which obstruction site and sampling quantity influence diagnostic efficacy. Methods: We retrospectively analyzed the clinical data of 47 patients with MBO who underwent PTCD combined with intraductal biopsy. The cohort was stratified into a hilar group (n=27) and a distal group (n=20). The study focused on evaluating the impact of sampling quantity and biochemical markers while comparing the characteristics of the 2 groups. Results: The technical success rate of the procedure was 100%. The overall pathologic diagnostic sensitivity was 85.1% (40/47). The biopsy positivity rate in the distal group (90.0%) was numerically slightly higher than that in the hilar group (81.5%), although the difference was not statistically significant ( P =0.682). In contrast, the median number of samples in the confirmed positive group was significantly higher than that in the negative/indeterminate group ( P =0.005). Furthermore, the postoperative complication rate was only 6.38%, with no severe adverse events reported. Conclusions: PTCD combined with intraductal forceps biopsy is a safe and effective diagnostic method. Although the difference between obstruction sites was not statistically significant, this study demonstrates that increasing sampling quantity is crucial for diagnosis. Obtaining at least 3 to 4 samples through multipoint sampling is recommended to ensure high diagnostic rates across different obstruction sites.