Needle-based confocal endomicroscopy for pancreatic cysts: the current agreement in interpretation

BACKGROUND AND AIMS

Diagnosis of pancreatic cystic lesions (PCLs) remains challenging. EUS with FNA is limited by sampling error and nondiagnostic cytology. Needle-based confocal laser endomicroscopy (nCLE) performed during EUS can be used to improve diagnostic yield via FNA by providing in vivo histology of PCLs. However, the interobserver agreement (IOA) of nCLE of PCLs has yet to be studied.

METHODS

Fifteen deidentified nCLE video clips of PCLs were sent to 6 interventional endoscopists at 5 institutions. Six variables were assessed for IOA: presence or absence of (1) vessels, (2) villi, (3) dark clumps, (4) reticular pattern, (5) acinar cells pattern, and (6) debris. PCL interpretation was categorized as mucinous, serous, pseudocyst, malignant, or indeterminate and final diagnosis as benign, malignant, or indeterminate.

RESULTS

IOA ranged from "poor" to "fair." The K statistics were -.04 (SE = .05) for vessels, .16 (SE = .07) for villi, .22 (SE = .06) for dark clumps, .13 (SE = .06) for reticular pattern, .14 (SE = .06) for acinar cells pattern, .06 (SE = .06) for debris, .15 (SE = .03) for interpretation, .13 (SE = .05) for final diagnosis, and .19 (SE = .05) for image quality. The final diagnosis was malignant (10), benign (13), and indeterminate (2). The mean accuracy of the observers was 46%, with the lowest being 20% and highest being 67%.

CONCLUSIONS

The IOA and accuracy for PCL diagnosis were low. The results of this study support the need to identify and validate imaging criteria to determine whether nCLE has diagnostic value for pancreatic pathology. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT02166086.).

Probe-based confocal laser endomicroscopy in the pancreatic duct provides direct visualization of ductal structures and aids in clinical management

BACKGROUND

Confocal endomicroscopy provides real-time evaluation of various sites and has been used to provide detailed endomicroscopic imaging of the biliary tree. We aimed to evaluate the feasibility and utility of probe-based confocal laser endomicroscopy of the pancreatic duct as compared to cytologic and histologic results in patients with indeterminate pancreatic duct strictures.

METHODS

Retrospective data on patients with indeterminate pancreatic strictures undergoing endoscopic retrograde cholangiopancreatography (ERCP) and confocal endomicroscopy were collected from two tertiary care centres. Real-time confocal endomicroscopy images were obtained during ERCP and immediate interpretation according to the Miami Classification was performed.

RESULTS

18 patients underwent confocal endomicroscopy for evaluation of pancreatic strictures from July 2011 to December 2012. Mean pancreatic duct size was 4.2mm (range 2.2-8mm). Eight cases were interpreted as benign, 4 as malignant, 4 suggestive of intraductal papillary mucinous neoplasms, and 2 appeared normal. Cytology/histopathology for 15/16 cases showed similar results to confocal endomicroscopy interpretation. Kappa coefficient of agreement between cyto/histopathology and confocal endomicroscopy was 0.8 (p=0.0001). Pancreatic confocal endomicroscopy changed management in four patients, changing the type of surgery from total pancreatectomy to whipple.

CONCLUSIONS

Confocal endomicroscopy is effective in assisting with diagnosis of indeterminate pancreatic duct strictures as well as mapping of abnormal pancreatic ducts prior to surgery.