False-negative factors of percutaneous transluminal clamp biopsy for biliary stricture: 194 case analyses from a single center

Objective: To study the predictive factors of false negatives in the diagnosis of biliary stricture (BS) by percutaneous transluminal clamp biopsy (PTCB). Method: From January 2016 to January 2021, 194 patients with a high suspicion of malignant tumors due to BS underwent PTCB during biliary drainage at our department. The final diagnosis was confirmed by postoperative pathology, other tissue or cell evidence, or medical imaging follow-up. Univariate and multivariate regression analyses were performed on the pathological results, summarizing the independent risk factors for false-negative value (FNV) to help further clinical diagnosis and treatment. Results: : Of the 194 cases, 144 and 18 cases were diagnosed as malignant and benign BS, respectively. The sensitivity, specificity, false-positive value and FNV of PTCB were 81.8%, 100%, 0% and 18.2%, respectively. Multivariate analysis showed that noncholangiocarcinoma PS was an independent risk factor for FNV of PTCB [odds ratio 7.5, (95% CI 1.74-32.6), p<0.01]. Conclusion: PTCB is an effective minimally invasive interventional technique for BS diagnosis. Noncholangiocarcinoma BS is an independent risk factor for FNV.