Background: Percutaneous transhepatic biliary drainage (PTBD) allows ductal material to be collected for cyto-histologic examination. We evaluated the data from a large series of patients with a PTBD in whom endobiliary cyto-histologic sampling techniques were employed in order to define a strategy for their use in the diagnostic work-up.
Patients and methods: Ductal samples for cyto-histologic examination were obtained from 409 consecutive patients with a PTBD for stenosing lesions of the biliary tree. Bile aspirate cytology was performed for all patients and ductal biopsy specimens were obtained, generally after negative cytology, from 49 of them (11.9%), all candidates for a therapeutic procedure. The cyto-histologic results of intraductal sampling were compared with pathologic surgical data in 210 patients and with clinical-radiologic follow-up in 199.
Results: Overall, 22 out of the 409 patients had a final diagnosis of benign stenosis and 177 had samples positive for neoplastic disease. The sensitivity of bile cytology was 43.8% while ductal biopsies showed a sensitivity of 60.4%. The combination of the two sampling techniques achieved a sensitivity of 65.1%. For both sampling methods the specificity was 100%. Hilar metastases from neoplastic lesions of the GI tract and primary lesions of the biliary ducts showed the highest sensitivity.
Conclusion: Cyto-histologic assessment of stenosing lesions of the biliary ducts is mandatory when highly sophisticated interventions (e.g. wide hepatic resection or liver transplantation) or non-surgical treatments are envisaged. The collection of cyto-histologic samples from bile ducts, in patients with a percutaneous bile drainage, is an easy, safe and valuable method to obtain the diagnosis. In view of the absence of false positive results in our series and in others, intraductal biopsy serves no purpose when positive exfoliative cytology is positive for malignancy. In the presence of negative cytology it is felt that an intraductal biopsy should be mandatory when the choice of a therapeutic program depends on the result of the cyto-histologic diagnosis.