Multimodal planning of vacuum-assisted fine-needle aspiration biopsy for focal liver lesions: A single-center comparative diagnostic study

Abstract

Background: Morphological verification of indeterminate liver lesions is essential to confirm metastasis and guide treatment. The diagnostic yield of standard fine-needle aspiration biopsy (FNAB) depends on suction stability and the choice of target zone. Vacuum-assisted FNAB (v-FNAB) provides controlled negative pressure using 20–25G needles; however, comparative clinical data remain limited. Aim: To evaluate the diagnostic yield and safety of ultrasound-guided v-FNAB for suspected metastatic liver lesions compared to standard FNAB and core needle biopsy. Methods: A single-center comparative non-randomized diagnostic study was conducted from December 2025 to May 2026, enrolling adult patients with focal liver lesions requiring morphological verification. To describe the target biopsy zone selection, one of five radiological target types was recorded: hypervascular solid lesion, hypovascular or infiltrative lesion, lesion with central necrosis or cystic degeneration, small and/or deeply located lesion, subcapsular lesion or lesion with limited safe access. The aspiration method was chosen by the operator. FNAB was performed with a syringe; v-FNAB was performed under a stable negative pressure of -0.8 bar; 20–25G needles and ultrasound guidance were used. Core-needle biopsy with 18–20G needles was performed in the same session. The primary endpoint was an informative aspirate; secondary endpoints were the proportion of non-informative results, pairwise comparison of the diagnostic yield of the aspiration method with core-needle biopsy, the association of needle gauge with the diagnostic yield of the method, and early complications. The reference diagnosis was established by informative core-needle biopsy or, if non-informative, by final clinical and morphological correlation. Results: Ninety-four patients with focal liver lesions were examined (53 men, 41 women; age 56.2 ± 10.0 years), with 47 in the FNAB and v-FNAB groups each. Age, sex, and lesion size did not differ between groups; in the v-FNAB group, metastatic (36 [76.6%] patients vs 24 [51.1%] in the FNAB group, p = 0.018) and multiple (32 [68.1%] cases vs 21 [44.7%], p = 0.037) liver lesions were more frequent. An informative aspirate was obtained in 29/47 FNAB cases (61.7%; 95% confidence interval [CI] 46.4–75.5) and in 43/47 v-FNAB cases (91.5%; 95% CI 79.6–97.6); p = 0.001. In the multivariable model, the adjusted odds ratio for an informative aspirate for v-FNAB was 8.42 (95% CI 2.43–29.18; p = 0.001). No association was found between needle gauge and the diagnostic yield of FNAB or v-FNAB. Core-needle biopsy was informative in 88/94 (93.6%) cases. Intraparenchymal hematomas were recorded in 4/94 (4.3%) patients after the combined procedure, including FNAB/v-FNAB and core-needle biopsy; no blood transfusion or surgical hemostasis was required. Conclusion: The rate of informative cytological samples was higher with v-FNAB than with standard FNAB (91.5% vs 61.7%), and the proportion of non-informative aspirates was lower (8.5% vs 38.3%). v-FNAB may be considered for inclusion in the diagnostic algorithm for patients with focal liver lesions. Multimodal imaging assessment was used to select a representative zone and a safe needle trajectory; however, the reproducibility of the described imaging types requires prospective validation.