Probe based confocal laser endomicroscopy of the pancreatobiliary system

Table 2 Performance of characteristics of findings on confocal laser endomicroscopy for pancreatobiliary strictures

Criterion	Author and the description of the examined area	Sensitivity	Specificity	PPV	NPV
	Meining et al[41,53]
Malignant biliary strictures	Loss of reticular pattern of epithelial bands of less than 20 μm	83%	88%	NR	NR
	Irregular epithelial lining, villi, or gland-like structures
	Tortuous, dilated, and saccular vessels with inconsistent branching
	Presence of “black areas” of more than 60 to 80 μm (focally decreased uptake of fluorescein)
	Meining et al[20]
Suggestive ofmalignancy	Thick, dark bands (> 40 μm)	98%	67%	71%	97%
	Thick, white bands (> 20 μm)
	Dark clumps
	Epithelium visualized (villi, glands)
	Fluorescein leakage
Suggestive ofbenign strictures	Thin, dark (branching) bands
	Thin, white bands
	Meining et al[14]
Normal bile ducts	Reticular network of thin dark branching bands (< 20 μm)	97%	33%	80%	80%
	Light gray background
	Vessels < 20 μm
Malignant biliary strictures	Thick white bands (> 20 μm)
	Thick dark bands (> 40 μm),
	Dark clumps
	Epithelial structures
	Normal vessels (thin and regular)
	No visible glands
	Giovannini et al[18]
Benign IPMN	Finger-like projections corresponding to villous changes of intestinal IPMN type	NR	NR	NR	NR
Pancreatic adenocarcinoma	Vascular leakage with irregular vessels with leakage of fluorescein into the tumor
	Large dark clumps which correspond to humps of malignant cells
Benign Lymph nodes	Diffuse small cells into a homogeneous stroma with normal vascularization
Malignant lymph nodes	Glandular structures with dark cells, large dark clumps and neo-vascularization with huge leakage of fluorescein
	Filoche et al[56]
Benign inflammatory strictures of the common bile duct	Vascular congestion but still regular	NR	NR	NR	NR
	Roughness aspect
	Increased inter-glandular space
	Thickened reticular structure
	Caillol et al[15]
Inflammatory stenosis	Multiple thin white bands (Vascular congestion)	96.3%	63.6%	68.4%	95.5%
	Roughness aspect
	Increased inter-glandular space
	Thickened reticular structure

IPMNs: Intraductal papillary mucinous neoplasms; NR: Not reported; PPV: Positive predictive value; NPV: Negative predictive value.