Comparison of Diagnostic Accuracy Before or After Stricture Dilation in Biliary Stricture
Comparison of Diagnostic Accuracy Before or After Stricture Dilation in Biliary Stricture
Biliary strictures present a diagnostic and therapeutic challenge to clinicians due to
 unsatisfied accuracy of sampling modality. The major problem is very difficult to discern
 malignant from non-malignant strictures, such as patients with primary sclerosing cholangitis
 (PSC). With the poor prognosis and high mortality rate of advanced stage of
 hepatopancreaticobiliary malignancies, early and accurate diagnosis impacts patients' outcome
 and possible surgical candidacy. Therefore, a pre-operative determination of malignancy to
 help plan appropriate treatment is highly desirable.

 Before 2000s, several diagnostic modalities, including laboratory tests, ultrasonography
 (US), computed tomography (CT) scan, cholangiography by percutaneous transhepatic
 cholangiography endoscopic (PTC) and endoscopic retrograde cholangiopancreatography (ERCP),
 and brushing cytology disclosed 13% to 24% false positive rate for suspicious malignant hilar
 strictures. Compared to recent studies, ERCP brushings still suffer from low sensitivity
 (41.6% ± 3.2% (99% CI)) and negative predictive value (58.0% ± 3.2% (99% CI)). In order to
 increase diagnostic accuracy, at least two sampling methods, including brushing cytology,
 biopsy, and fine-needle aspiration is therefore recommended. One article showed multimodal
 tissue-sampling (Brushing + Biopsy + Fine-needle aspiration) increased the sensitivity for
 diagnosis of malignant biliary stricture to 62%. However, no any literature demonstrate the
 best sequence of combined sampling modalities to yield the highest diagnostic accuracy.
 Besides, the role of stricture dilation before or after different tissue sampling modality is
 still uncertain.

 In this study, the investigators want to compare stricture dilation before or after
 multimodal tissue-sampling, including brush cytology, intraductal suction and forceps biopsy
 for the diagnosis of malignant biliary stricture and also assess which kind of the sequence
 of combined tissue-sampling modalities could offer the highest diagnostic accuracy.
Inclusion Criteria:

 -  Clinically suspicious biliary stricture that required tissue sampling as medically
 indicated were considered for the study

 Exclusion Criteria:

 -  Biliary stricture caused by extra-luminal compression, such as pancreatic cancer and
 lymphadenopathy

 -  Contraindication for ERCP study

 -  Age younger than 20 years

 -  Prior tissue sampling had yielded a diagnosis of malignancy

 -  A guidewire could not be passed through the stricture

 -  Less than 6-month follow-up was available for patients with negative tissue sampling