TM
Brush
Prospective, Randomized, Single-blinded controlled trial of Infinity Cytology
Standard Cytology Brush for diagnosis of biliary stricture: An interim analysis
vs
Nirav Thosani, MD, MHA, Subhas Banerjee, MD, Ann M. Chen, MD, Shai Friedland, MD
Division of Gastroenterology & Hepatology
Stanford University, Stanford, CA
Background & Aim
•
•
•
•
Figure 1: Infinity Cytology Brush vs Standard Cytology Brush
• A total of 37 patients with biliary strictures were enrolled
Since its initial description in 1975, brushing has been
used extensively for diagnosis of biliary strictures
detected during ERCP due to excellent safety profile
and relative ease of use.
Variables
Despite having specificity close to 100%, brushing
suffers from low sensitivity (30%-57%) and low negative
predictive value (58%).
Infinity cytology brushTM (ICB) had unique bristle
configuration, with stiffer bristles at both ends which
helps to exfoliate the cells and softer bristles in middle
which are designed to capture the exfoliated cells.
The aim of our study is to determine the accuracy of
ICB vs standard cytology brush (SCB) in diagnosis of
biliary stricture in randomized blinded controlled trial.
Infinity Cytology Brush
Standard Cytology Brush
Figure 2: Bile Duct Brushing Smears
Methods
•
•
Age
Sex (Male)
Stricture location
Distal
Mid CBD
Hilar
Proximal (R or L main
hepatic duct)
Final Diagnosis
Benign
Malignant
A randomized study of patients with biliary stricture
undergoing ERCP with brushing is currently undergoing
at our institute since September 2013.
Pathologists are blinded to the type of brush and rate
each brushing sample for adequate cellularity.
•
Accurate diagnosis is defined as brushing sample with
(1) sufficient cellularity as per Camps grading method
and (2) suspicious or diagnostic for malignancy in
patients with cancer & normal or atypical in patients
without cancer, as determined based on diagnostic
interventions and clinical follow up.
Infinity
Standard
Cytology Brush Cytology Brush
(n=17)
(n=20)
63 ± 14
12 (71%)
67 ± 12
13 (65%)
13 (76%)
0 (0%)
3 (18%)
13 (65%)
1 (5%)
4 (20%)
1 (6%)
2 (10%)
p value
0.24
0.72
0.74
Standard
Cytology Brush
(n=20)
Overall Accuracy
Malignant Stricture
Benign Stricture
Cellularity
Acellular or Scant
13/15 (87%)
6/8 (75%)
7/7 (100%)
12/20 (60%)
4/8 (50%)
8/12 (67%)
0 (0%)
6/20 (30%)
Mild or Moderate
15/15 (100%)
14/20 (70%)
Variables
(A) Normal: Large monolayer sheet of benign cells without nuclear overlapping; (B) Atypical consider reactive: Cohesive group of cells with mild
nuclear enlargement and scattered nucleoli; (C) Suspicious: Cells with large overlapping nuclei, prominent nucleoli & granulocytes in the
background; (D) Malignant: Cells with increased nucleocytoplasmic ratio, irregular thickened nuclear membrane, marked anisocaryosis, loss of
polarity & prominent nucleoli. Ref: Domonceau JM, Am J Gastroenterol 2007; 102: 550-557
• Both groups were similar in regards to basic
demographics, stricture location and final diagnosis
(benign vs malignant).
compared to accuracy of 60% (12/20) with SCB, however
this trend did not reach statistical significance (p =0.08).
• For malignant strictures, accuracy of ICB was 75% (6/8)
compared to accuracy of 50% (4/8) with SCB (p=0.3).
• For benign strictures, accuracy of ICB was 100% (7/7)
compared to accuracy of 67% (8/12) with SCB (p=0.09).
12 (60%)
8 (40%)
Infinity Cytology
Brush (n=17)
patients etiology of biliary stricture is still under evaluation.
• The ICB had higher diagnostic accuracy of 87% (13/15)
0.43
7 (47%)
8 (53%)
(Table 1). 20 (54%) patients were randomized to SCB
while 17 (46%) patients were randomized to ICB.
• Final diagnosis was reached in 35 patients, while in two
• About 30% (6/20) of SCB samples were grades as
acellular or scant by pathologist. All (100%)ICB samples
were graded as mild or moderate cellularity compared to
only 70% with SCB (p=0.02).
Table 2: Outcomes
Patients are randomized to either brush using
computerized random sequence generation in
concealed envelops. All patients undergo dilation of the
stricture prior to brushing per protocol. Brushings were
done in standard fashion.
•
Results
Table 1: Demographics
• In mixed-effect logistic regression analysis, age, sex,
brush type, stricture location or cellularity were not
associated factors for diagnostic accuracy.
p value
0.08
0.3
0.09
0.02
Conclusions
• In our interim analysis, we found fewer insufficient samples
and most samples with adequate cellularity with ICB and a
trend towards higher diagnostic accuracy with ICB. We
plan to enroll 63 patients in each arm based on our power
calculation.
© 2014 Mayo Foundation for Medical Education and Research