Clinical utility of directional eFLOW compared with contrast-enhanced harmonic endoscopic ultrasound for assessing the vascularity of pancreatic and peripancreatic masses.

BACKGROUND: Contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) can be used for the differential diagnosis of pancreatic lesions by evaluating microvascular circulation and patterns of contrast enhancement. However, routine use of CEH-EUS is limited by its high cost, the lack of contrast agent availability and the absence of expertise with this technique. Directional eFLOW (D-eFLOW) (Aloka Co., Ltd., Tokyo, Japan) was introduced as a new high-definition modality that detects blood flow in microvessels. Because it uses built-in functions, it entails no additional cost and reduces time for examination. The present study compared the usefulness of D-eFLOW and CEH-EUS for differential diagnosis of pancreatic and peripancreatic lesions. METHODS: This retrospective study analyzed 130 patients who underwent EUS and D-eFLOW examinations from January 2016 to March 2020 to evaluate pancreatic and peripancreatic masses. RESULTS: All 130 patients underwent D-eFLOW and CEH-EUS examinations. Histological diagnoses were confirmed in 130 patients by EUS-FNA and/or surgery. D-eFLOW and CEH-EUS showed good correlation in evaluating the vascularity of pancreatic and peripancreatic tumors (Fisher's exact test, p < 0.05). CONCLUSIONS: In evaluating the characteristics of tumorous lesions, vascularity detected by D-eFLOW showed good correlation with enhancement patterns of CEH-EUS. D-eFLOW can be considered a good alternative to CEH-EUS in diagnosing pancreatic and peripancreatic masses.

Usefulness of indocyanine green-fluorescence imaging for real-time visualization of pancreas neuroendocrine tumor and cystic neoplasm.

We evaluated the usefulness of fluorescence imaging using indocyanine green to identify pancreas tumors in 23 patients undergoing pancreas resection. This technique was useful in visualizing pancreas lesions during surgery, specifically, neuroendocrine tumors as fluorescence and cystic neoplasms as a fluorescence defect.

Preliminary study of single-operator cholangioscopy for diagnosing pancreatic cystic lesions.

BACKGROUND AND AIMS: Advances in imaging technology have improved the annual detection rate of pancreatic cystic lesions (PCLs), but the preoperative diagnosis of PCLs remains unclear. Thus, the usefulness of single-operator cholangioscopy (SOC) as a diagnostic imaging tool for PCLs is worth investigating. We performed an intracystic visual examination of PCLs using SOC to determine the diagnostic value of SOC for PCLs. METHODS: In this retrospective observational study, PCLs were confirmed using a diagnostic imaging modality. Patients who underwent an EUS-guided through-the-needle fiberoptic pancreatic cystoscopy and SOC examination and those whose lesion type was definitively diagnosed were included (n = 43). If the cystic fluid was turbid, a physiologic saline solution was injected into the cyst, and a SOC fiberoptic probe was inserted through a 19-gauge needle to observe the wall of the intracystic cavity and its contents. The characteristics were recorded, and the cystic fluid and biopsy specimens were further assessed by performing liquid-based cytologic and histopathologic examinations. Particularly, histopathologic examinations were performed in patients who underwent surgery. RESULTS: Intracystic characteristics of the confirmed cases of PCLs (43 patients) were identified through intracystic visual examination with SOC. The clarity of cyst fluid is a prerequisite for imaging by SOC. The tree-like branching pattern of blood vessel distribution may be a serous cystic neoplasm-specific characteristic. Intracystic papilla-like structure is an important characteristic for diagnosing mucinous cystic neoplasms. CONCLUSIONS: The identified imaging characteristics such as blood vessel distribution on the intracystic wall and the contents of different PCLs observed under the SOC probe can provide useful information for diagnosing PCLs. SOC could be an important ancillary imaging test of PCLs by EUS.

Current indications and yield of endoscopic ultrasound and ancillary techniques in pancreatic cystic neoplasms.

An increase in the diagnosis of pancreatic cystic neoplasm has been described lately. Surgical treatment or surveillance is advised depending on the type of lesion diagnosed. The most accurate diagnostic approach is needed to make the best therapeutic decision. Endoscopic ultrasound is a very valuable tool in the evaluation of pancreatic cystic neoplasm. It generates high-quality images and allows the possibility of sampling the cystic fluid for cytology, microbiological and molecular evaluation. Even with this evaluation, the sensitivity of this approach is not always adequate. New technological resources have been developed to try to improve the diagnostic accuracy of pancreatic cystic neoplasms. The two most promising techniques are needle-based confocal laser endomicroscopy and contrast-enhanced harmonic endoscopic ultrasound. Needle-based confocal laser endomicroscopy allows a microscopic evaluation of mucosal glands and vascular pattern, to differentiate mucinous from non-mucinous lesions. Contrast-enhanced harmonic endoscopic ultrasound is used for the vascular evaluation of the microcirculation of the cyst wall and mural nodule, mainly to make the difference between malignant nodules and mucus plugs. A combination of these different diagnostic techniques can improve the diagnostic accuracy of pancreatic cystic neoplasms to offer the adequate therapeutic decision.