Accuracy and safety of percutaneous US-guided needle biopsies in specific focal liver lesions: comparison of large and small needles in 1300 patients.

AIM: The aim of this study was to compare small size aspiration needles with large size cutting needles in focal liver lesions for using small needles instead of large ones without on-site cytopathologist.
METHODS: Percutaneous ultrasonography-guided liver biopsy was evaluated retrospectively in a biopsy cohort study of 1300 patients. In this series, 690 patients were biopsied with large size (<19G) cutting needles and 610 with small size (20G) aspiration needles. On-site cytopathologist was not present in the biopsy-room at any intervention. Needles were compared for diagnostic accuracy and safety for various focal liver diseases.
RESULTS: We had diagnostic accuracy rate of 85.0% in small needle group vs. 96.9% in large needle group with metastasis (P<0.001). This rate was 85.5% in small needle group vs. 97.9% in large needle group with hepatocellular carcinoma (P=0.039). Accuracy rates of them were not different in hemangioma (P=0.277) and infection-inflammation (P=0.470). This rate was 75.0% in small needle group vs. 98.9% in large needle group with regenerative nodules (P=0.018). These rates were not different in focal steatosis (P=1.000). Sensitivity, specificity, and accuracy were 85.1%, 100%, and 89.2%, respectively. Only 2 (0.15%) major complications were found with small needles in uncooperative patients. Any major complication was not seen in hemangioma.
CONCLUSION: In uncertain diagnosis with modern imaging, we propose that large size cutting needles should be used in suspected liver metastasis, hepatocellular carcinoma, and regenerative nodules if cytopathologist was not present. Small needles can be successfully used as well as large ones in focal steatosis, infection-inflammation, and hemangioma of liver in unclear diagnosis.