Assessment of different modalities for repeated tissue acquisition in diagnosing malignant biliary strictures: A two-center retrospective study.

ABSTRACT

OBJECTIVE: Various modalities are applied for pathological diagnosis of malignant biliary strictures (MBS), including brush cytology (BC), forceps biopsy (FB) and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). We aimed to assess the value of these modalities in a repeated tissue acquisition process for biliary strictures with initially inconclusive pathological outcomes. METHODS: Patients who were suspected of having MBS and underwent a BC in two large teaching hospitals were retrospectively included. The sensitivity, specificity, positive and negative predictive values, and accuracy of the initial and repeated BC, FB and EUS-FNA were analyzed. Their performances were compared to determine which modality was superior in repeated tissue acquisition. RESULTS: In total, 476 patients were included. The sensitivity, specificity and accuracy in diagnosing MBS for the initial BC were 30.3%, 100% and 55.0%, respectively. Altogether 39, 27 and 44 patients underwent a repeat BC, FB and EUS-FNA, respectively. The sensitivity for repeated BC, FB and EUS-FNA was 41.2%, 61.1% and 44.4%, respectively, whereas their specificity all reached 100%. When comparing diagnostic accuracy, none of the modalities was superior (74.4% vs 74.1% vs 54.5%, P = 0.173). In the repeated process, one patient who underwent BC and two underwent FB developed mild pancreatitis. CONCLUSIONS: Repeated tissue acquisition achieves a conclusive diagnosis of MBS in nearly half patients who have an initially inconclusive cytological diagnosis. None of the tissue acquisition methods is significantly superior in the repeated process.