Hepatic Vein–Inferior Vena Cava Confluence Angle as a Key Anatomical Predictor of Technical Success in Transjugular Liver Biopsy

Background/Objectives: Transjugular liver biopsy (TJLB) occasionally fails, most commonly because of difficulty in hepatic vein (HV) catheterization. We investigated whether the HV–inferior vena cava (IVC) confluence angle measured on CT or MRI could predict the technical success of TJLB. Methods: This single-center retrospective cohort study included 100 patients who underwent TJLB. Technical success was defined as the successful catheterization of the HV and acquisition of liver tissue. The HV–IVC confluence angle was measured on CT or MRI. Factors were compared between successful and unsuccessful cases. Multivariable Firth logistic regression was performed to assess factors associated with technical failure. ROC analysis was performed to evaluate the discriminatory performance of the HV–IVC confluence angle. Results: TJLB was technically successful in 86 of 100 cases. On univariate analysis, age, sex, height, and HV–IVC confluence angle were associated with TJLB success. The confluence angle was significantly smaller in successful than in unsuccessful cases (43.6 ± 11.1° vs. 59.3 ± 11.2°, p = 0.001). In multivariable Firth logistic regression, age and the confluence angle were associated with technical failure (odds ratios, 1.08 per year and 1.16 per degree, respectively). The area under the curve was 0.85, and the exploratory cutoff was 56°. Conclusions: A larger HV–IVC confluence angle was associated with technical failure and may be a promising imaging biomarker. Given limited measurement feasibility and no external validation, the 56° cutoff should remain exploratory.