Evaluation of novel slim biopsy forceps for diagnosis of biliary strictures: Single-institutional study of consecutive 360 cases (with video)

Table 1 Patient characteristics

Patient characteristics
Number of patients	360
Age [mean ± SD (range), yr]	71 ± 11.8 (17-95)
Sex, male/female	241/119
Disease (number of patients)
Bile duct cancer	132
Pancreatic cancer	86
Gallbladder cancer	18
Metastasis	14
Benign stricture	110

Table 2 Overall diagnostic ability in all cases (n = 360)

Sample collection rate
Total number of biopsies	820
Mean number of biopsies, ± SD (range)	2.28 ± 0.91 (1-6)
Overall results
Sensitivity	69.6%
Specificity	100%
PPV	100%
NPV	59.1%
Accuracy	78.8%

PPV: Positive predictive value; NPV: Negative predictive value.

Table 3 Overall sensitivity for malignancy

Diagnosis	n	Sensitivity
Bile duct cancer	100/132	75.6%
Pancreatic cancer	55/86	64.0%
Gallbladder cancer	11/18	61.1%
Metastasis	8/14	57.1%

Table 4 Sensitivity of biopsy forceps in bile duct cancer

	n	Sensitivity
Total	100/132	75.60%
Site of stricture
Perihilar bile duct	46/67	68.7%
Distal bile duct	54/65	83.1%
Middle	21/22	95%
Lower	33/43	76.7%
(Open space +	22/26	84.6%
(Open space −	11/17	64.7%

Table 5 Sensitivity of biopsy forceps in extrinsic neoplasms

	n	Sensitivity
Pancreatic cancer	55/86	64.0%
Site of stricture
Middle bile duct	5/11	45.5%
Lower bile duct	50/75	66.7%
Localization of tumor
Head	52/76	68.4%
Body	3/10	30.0%
Gallbladder cancer	11/18	61.1%
Site of stricture
Perihilar bile duct	6/11	54.5%
Distal bile duct	5/7	71.4%
Metastasis	8/14	57.1%
Site of stricture
Perihilar bile duct	4/6	66.7%
Distal bile duct	4/8	50.0%

Table 6 Mean stricture lengths in extrinsic neoplasms

	Positive (mm)	Negative (mm)	P value
Pancreatic cancer	16.9	13.5	< 0.05
Gallbladder cancer	22	13.4	< 0.05
Metastasis	17.1	13.2	NS

NS: Not significant.

Table 7 Characteristics of studies evaluating bile duct biopsies

Study	Year	Sample size (n)	Sensitivity, %
Pugliese et al[1]	1995	94	53
Ponchon et al[3]	1995	233	43
Howell et al[10]	1996	28	15
Sugiyama et al[11]	1996	52	81
Jailwala et al[2]	2000	133	37
Rösch et al[12]	2004	50	36
Kitajima et al[13]	2007	60	65
Weber et al[14]	2008	58	53
Our case	2016	360	70