Preliminary single-operator experience with ultrasound-guided liver core needle biopsy performed by a supervised general surgery resident

Objective: Ultrasound-guided core needle biopsy (CNB) is essential for diagnosing liver tumors not amenable to resection, but the outcomes of resident-performed CNB are poorly defined. We evaluated the diagnostic performance and safety of liver CNB performed by a single ultrasound-certified general surgery resident under specialist supervision. Material and Methods: In this retrospective single-center case series, 65 consecutive patients underwent ultrasound-guided liver CNB between July 2022 and January 2025. All procedures constituted the resident's entire initial experience with liver CNB. Diagnostic success was defined as obtaining sufficient tissue for definitive histopathological diagnosis. Predictors of diagnostic success were assessed using univariate analyses and logistic regression. Learning-curve effects were evaluated by comparing early and late tertiles of chronologically ordered cases and by modelling case number as a continuous predictor. The impact of lesion size was examined by subgroup analysis comparing