Advances of Peroral Cholangioscopy and EUS for Indeterminate Biliary Lesions

Traditionally, biliary lesions have been considered to be indeterminate when a diagnosis cannot be made after basic laboratory work-up, abdominal imaging and endoscopic retrograde cholangiopancreatography (ERCP) with biliary sampling. Although ERCP is a first-line diagnostic modality for indeterminate biliary lesions, the diagnostic yield of ERCP-based tissue sampling is insufficient. In a recent, peroral cholangioscopy (POC)- guided forceps biopsy and endoscopic ultrasound-guided fine-needle aspiration (EUSFNA) are evolving as reliable diagnostic procedures for indeterminate biliary lesions. In previous studies, EUS-FNA was sensitive and highly specific for diagnosing malignancy in biliary strictures. However, EUS-FNA has several limitations as a routine clinical procedure for all biliary strictures. Newly developed POC systems, such as the SpyGlass direct visualization system and direct POC using an ultra-slim endoscope, have led to excessive improvements in technical performance and diagnostic yields for biliary strictures. However, the performance of POC-guided target biopsy for distal bile duct strictures is technically difficult, and this approach has a limited ability to diagnose biliary strictures caused by non-intraductal, extrinsic compressed malignancies, such as a pancreatic cancer. Therefore, a tailored approach using optimized endoscopic modalities that are specific to the characteristics of a given biliary stricture is needed to achieve a high diagnostic yield for indeterminate biliary lesions.

Transcatheter Examination of the Peritoneal Dialysis Catheter with the SpyGlass Direct Visualization System: A New Aid in Diagnosis and Salvation of Ultrafiltration Failure from Partial Catheter Obstruction

Mechanical complications in peritoneal dialysis (PD), including intraluminal clogging of the PD catheter by fibrin, omentum, or blood clot, are major causes of outflow problems and, in rare cases, lead to technical failure. To visualize an intraluminal image of patients undergoing PD with ineffective ultrafiltration (UF), a SpyGlass fiber optic probe was inserted into the catheter, together with SpyBite biopsy forceps, should the removal of clogging materials be needed. Applying these transcatheter devices in 2 PD patients with unexplained UF failure led to the demonstration of omental plugging at the catheter tip in the first patient and demonstration of intraluminal blood clots in the second patient from whom clots were removal successfully. Both patients achieved better UF volume thereafter without procedure-related complications.

Evaluation of Pulmonary Nodules Using the Spyglass Direct Visualization System Combined With Radial Endobronchial Ultrasound: A Clinical Feasibility Study

Background: Sampling of peripheral pulmonary nodules with radial endobronchial ultrasound (p-EBUS) increases diagnostic yield of bronchoscopy. However, diagnostic yield is influenced by numerous factors. Objective: We evaluated the use of SpyGlass, a one millimeter diameter optic fiber, to obtain images of the distal mucosa and of pulmonary lesions detected with p-EBUS to determine if visual aspect of the distal mucosa was predictive of diagnosis. Methods: We prospectively recruited subjects investigated for peripheral nodules. Bronchoscopy was performed and p-EBUS was used to locate the lesion through a guide sheath. The Spyglass fiber was introduced in the sheath to obtain images of the distal bronchial mucosa. Tissue sampling was subsequently done. Results: Fifteen patients were enrolled in the study. A final diagnosis of malignancy was confirmed in 80%. All lesions could be located using p-EBUS (100%). Diagnostic sensitivity for p-EBUS was 58.3%. Distal mucosa could be imaged with SpyGlass in 14/15 patients (93.3%). Mucosal appearance was described as abnormal in 7 out of the 15 subjects. Mean SpyGlass procedure time was 6.5 minutes. No direct complication was reported. Conclusion: Spyglass can be used in combination with p-EBUS to obtain images of the distal bronchial mucosa and peripheral pulmonary nodules. More patients will be needed to confirm whether mucosal appearance can be predictive of malignancy.

Interobserver Agreement for Single Operator Choledochoscopy Imaging: Can We Do Better?

Background. The SpyGlass Direct Visualization System (Boston Scientific, Natick, MA) is routinely used during single operator choledochoscopy (SOC) to identify biliary lesions or strictures with a diagnostic accuracy up to 88%. The objective of this study was to determine the interobserver agreement (IOA) of modified scoring criteria for diagnosing biliary lesions/strictures. Methods. 27 SPY SOC video clips were reviewed and scored by 9 interventional endoscopists based on published criteria that included the presence and severity of surface structure, vasculature visualization, lesions, and findings. Results. Overall IOA was “slight” for all variables. The K statistics are as follows: surface (K=0.12, SE = 0.02); vessels (K=0.14, SE = 0.02); lesions (K=0.11, SE = 0.02); findings (K=0.08, SE = 0.03); and final diagnosis (K=0.08, SE = 0.02). The IOA for “findings” and “final diagnosis” was also only “slight.” The final diagnosis was malignant (11), benign (11), and indeterminate (5). Conclusion. IOA using the modified criteria of SOC images was slight to almost poor. The average accuracy was less than 50%. These findings reaffirm that imaging criteria for benign and malignant biliary pathology need to be formally established and validated.