Diagnostic performance of a new endoscopic scraper for malignant biliary strictures: a multicenter prospective study

The efficacy of ERCP for histologic diagnosis of malignant biliary strictures is disappointingly low. The aim of this study was to investigate the diagnostic performance of a newly developed endoscopic device with scraping loops in combination with conventional biopsy forceps.

We performed a multicenter single-arm prospective study. Between February 2013 and December 2014, 123 patients with suspected malignant biliary strictures were enrolled in the study. The new device and conventional biopsy forceps were applied for histologic diagnosis by ERCP. The primary outcome was to evaluate cancer detectability by biopsy forceps, the new device, and their combined use.

Of the 123 patients, 119 were diagnosed with a malignant stricture. Sufficient samples were collected in 83.7% (103/123), 93.5% (115/123), and 95.9% (118/123) of patients using biopsy forceps, the new device, and their combination, respectively. Cancer detectability of forceps biopsy, the new device, and their combination were 51.3% (61/119), 64.7% (77/119), and 74.8% (89/119), respectively. The new device had a significantly higher sample yield and cancer detectability than biopsy forceps (P < .01 and P = .018, respectively, McNemar test). Complementary use of the new device with biopsy forceps demonstrated a significantly additive effect in both sample yield and cancer detection (P < .01 each, McNemar test). The new device detected 48.3% (28/58) of cancers that were not diagnosed as malignant by biopsy forceps.

The new endoscopic scraper demonstrated a large sample yield and high cancer detectability. It could be a first-line tissue-sampling device for biliary strictures. (University Hospital Medical Information Network Clinical Trial Registry [UMIN-CTR] (http://www.umin.ac.jp/ctr/index.htm) registration number: UMIN000009895.).