Safety and efficacy of novel oblique-viewing scope for B2-endoscopic ultrasound-guided hepaticogastrostomy.

Background/Aims: Endoscopic ultrasound (EUS)-guided hepaticogastrostomy (EUS-HGS) performed at the intrahepatic bile duct segment 3 (B3) is widely used for biliary drainage. Although performing post-puncture procedures is easier in the intrahepatic bile duct segment 2 (B2) when using a conventional oblique-viewing (OV) EUS scope, this method may cause transesophageal puncture and severe adverse events. We evaluated the safety and efficacy of B2 puncture using a novel OV-EUS scope. Methods: In this single-center retrospective study, we prospectively enrolled and collected data from 45 patients who consecutively underwent EUS-HGS procedures with a novel OV-EUS scope between September 2021 and December 2022 at our cancer center. Results: The technical success rates of B2-EUS-HGS and EUS-HGS were 93.3% (42/45) and 97.8% (44/45), respectively. The early adverse event rate was 8.9% (4/45) with no cases of scope changes or transesophageal punctures. The median procedure time was 13 minutes (range, 5-30). Conclusions: B2-EUS-HGS can be performed safely with the novel EG-740UT (Fujifilm) OV-scope without transesophageal puncture and with a high success rate. B2-EUS-HGS using this novel OV scope may be the preferred strategy for EUS-HGS.

Clinical utility of endoscopic ultrasound-guided tissue acquisition for comprehensive genomic profiling of patients with biliary tract cancer, especially with intrahepatic cholangiocarcinoma.

BACKGROUND/AIMS: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is a standard diagnostic method for biliary tract cancer (BTC), and samples obtained in this manner may be used for comprehensive genomic profiling (CGP). This study evaluated the utility of EUS-TA for CGP in a clinical setting and determined the factors associated with the adequacy of CGP in patients with BTC. METHODS: CGP was attempted for 105 samples from 94 patients with BTC at the Aichi Cancer Center, Japan, from October 2019 to April 2022. RESULTS: Overall, 77.1% (81/105) of the samples were adequate for CGP. For 22-G or 19-G fine-needle biopsy (FNB), the sample adequacy was 85.7% (36/42), which was similar to that of surgical specimens (94%, p=0.45). Univariate analysis revealed that 22-G or larger FNB needle usage (86%, p=0.003), the target primary lesions (88%, p=0.015), a target size ≥30 mm (100%, p=0.0013), and number of punctures (90%, p=0.016) were significantly positively associated with CGP sample adequacy. CONCLUSIONS: EUS-TA is useful for CGP tissue sampling in patients with BTC. In particular, the use of 22-G or larger FNB needles may allow for specimen adequacy comparable to that of surgical specimens.

Diagnostic performance and safety of endoscopic ultrasound-guided fine-needle aspiration/biopsy for gallbladder lesions.

OBJECTIVES: Endoscopic ultrasound-guided fine-needle aspiration and fine-needle biopsy (EUS-FNA/FNB) is not fully established as a pathological sampling tool for gallbladder lesions due to limited evidence. We therefore aimed to clarify the effectiveness and safety of this procedure in a large-population cohort. METHODS: This study retrospectively evaluated the diagnostic yield of EUS-FNA/FNB for accurately differentiating between benign and malignant gallbladder lesions. Puncture targets included the gallbladder mass, lymph node, and liver mass. Adverse events and factors associated with diagnostic accuracy were analyzed as well. RESULTS: In 187 patients with gallbladder lesions undergoing EUS-FNA/FNB, 18 benign lesions and 169 malignant lesions were identified. Overall sampling adequacy was 98% (184/187). The diagnostic accuracy of EUS-FNA/FNB was 97% (182/187), sensitivity was 97% (164/169), and specificity was 100% (18/18). A single postprocedural complication (minor bleeding) was recorded in one patient. In the 169 cases of malignancy, 203 sites were punctured for pathological sampling of the primary mass (n = 94), lymph node (n = 79), and metastatic liver mass (n = 30). No significant difference was found for diagnostic accuracy among the puncture sites (P = 0.70). In cases having specimens obtained from the primary mass, the accuracy of those targeting liver invasion sites was significantly higher than that of other sites (98% vs. 83%, P < 0.01). CONCLUSION: EUS-FNA/FNB demonstrated clinical usefulness and safety for the pathological diagnosis of gallbladder lesions, with high diagnostic yield and a low incidence of adverse events. Targeting the site of liver infiltration may improve the diagnostic rate of EUS-FNA/FNB in the primary mass.

Safety of endoscopic ultrasound-guided hepaticogastrostomy in patients with malignant biliary obstruction and ascites.

BACKGROUND/AIMS: Endoscopic ultrasound (EUS)-guided hepaticogastrostomy (EUS-HGS) is useful for patients with biliary cannulation failure or inaccessible papillae. However, it can lead to serious complications such as bile peritonitis in patients with ascites; therefore, development of a safe method to perform EUS-HGS is important. Herein, we evaluated the safety of EUS-HGS with continuous ascitic fluid drainage in patients with ascites. METHODS: Patients with moderate or severe ascites who underwent continuous ascites drainage, which was initiated before EUS-HGS and terminated after the procedure at our institution between April 2015 and December 2022, were included in the study. We evaluated the technical and clinical success rates, EUS-HGS-related complications, and feasibility of re-intervention. RESULTS: Ten patients underwent continuous ascites drainage, which was initiated before EUS-HGS and terminated after completion of the procedure. Median duration of ascites drainage before and after EUS-HGS was 2 and 4 days, respectively. Technical success with EUS-HGS was achieved in all 10 patients (100%). Clinical success with EUS-HGS was achieved in 9 of the 10 patients (90 %). No endoscopic complications such as bile peritonitis were observed. CONCLUSION: In patients with ascites, continuous ascites drainage, which is initiated before EUS-HGS and terminated after completion of the procedure, may prevent complications and allow safe performance of EUS-HGS.

Association of high-risk stigmata and worrisome features with advanced neoplasia in intraductal papillary mucinous neoplasms (IPMN): A systematic review.

BACKGROUND: This systematic review aimed to assess the diagnostic accuracy of the International Consensus Fukuoka Guidelines (ICG2017) in identifying high-risk lesions of Intraductal Papillary Mucinous Neoplasms (IPMNs). METHODS: The ICG2017 revision committee conducted a comprehensive literature review to establish evidence-based statements on IPMNs. The review focused on articles examining the diagnostic value of imaging features (e.g., cyst or main pancreatic duct diameter), clinical symptoms associated with IPMN, and serum biomarkers. Five clinical questions regarding high-risk stigmata (HRS) and worrisome features (WF) in the ICG2017 guidelines were addressed. RESULTS: A total of 210 articles were reviewed. The findings revealed a significant association between the presence of mural nodules ≥5 mm in diameter or solid components with contrast enhancement and the diagnosis of high-grade dysplasia or invasive carcinoma. Contrast-enhanced diagnostic tools, such as CT, MRI, or EUS, demonstrated the highest prediction rate and were recommended. Positive cytology was identified as an HRS, while symptoms like acute pancreatitis and cyst diameter growth ≥2.5 mm per year were considered WFs. The use of nomograms and multiple diagnostic factors was recommended for optimal IPMN management. CONCLUSIONS: This systematic review provides evidence supporting the improved diagnostic accuracy of ICG2017 in identifying high-risk lesions of IPMN. The multidisciplinary incorporation of HRS and WF based on imaging findings and clinical symptoms is crucial. These findings should inform the revision of ICG2017, enhancing the evaluation and management of IPMN patients. By implementing these recommendations, clinicians can make more informed decisions, leading to better diagnosis and treatment outcomes for high-risk IPMN cases.

The role of needle-based confocal laser endoscopy in the diagnosis of pancreatic neuroendocrine tumors.

Background/Aims: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a highly accurate method for diagnosing pancreatic neuroendocrine tumors (PNETs); however, some PNETs are difficult to diagnose. Recently, the efficacy of needle-based confocal laser endomicroscopy (nCLE) in diagnosing solid pancreatic masses has been reported. However, the efficacy of nCLE in the diagnosis of PNETs remains unknown and only a small number of cases have been reported. Hence, this study aimed to evaluate the efficacy of nCLE in the diagnosis of PNETs. Methods: This single-center retrospective study evaluated 30 consecutive patients with suspected PNETs on contrast-enhanced computed tomography, who consented to nCLE combined with EUS-FNA and were diagnosed using EUS-FNA or surgical resection. The diagnostic criteria for PNETs using nCLE were based on the nesting and trabecular and glandular arrangement of tumor cell clusters surrounded by capillary vessels and fibrosis, as reported in previous studies. Results: The diagnosis using nCLE was classified into three categories: misdiagnosis in three cases (10%), non-diagnostic in six cases (20%), and diagnostic in 21 cases (70%). nCLE was able to diagnose PNET in one of the two cases with inconclusive EUS-FNA. Conclusions: Although further development of the resolution and optimization of the diagnostic criteria are required, nCLE may constitute a useful diagnostic option in cases of inconclusive EUS-FNA for PNETs.

Endoscopic ultrasound-guided hepaticogastrostomy by puncturing both B2 and B3: a single center experience.

Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) through ducts B2 or B3 is effective in most patients with biliary obstruction, because B2 and B3 commonly join together. However, in some patients, B2 and B3 do not join each other due to invasive hilar tumors; therefore, single-route drainage is insufficient. Here, we investigated the feasibility and efficacy of EUS-HGS through both B2 and B3 simultaneously in seven patients. We decided to perform EUS-HGS through both B2 and B3 to achieve adequate biliary drainage because these two ducts were separate from each other. Here, we report a 100% technical and overall clinical success rate. Early adverse effects were closely monitored. Minimal bleeding was reported in one patient (1/7) and mild peritonitis in one patient (1/7). None of the patients experienced stent dysfunction, fever, or bile leakage after the procedure. EUS-HGS through both B2 and B3 simultaneously is safe, feasible, and effective for biliary drainage in patients with separated ducts.

Clinical utility of endoscopic ultrasound-guided tissue acquisition for comprehensive genomic profiling of pancreatic cancer.

BACKGROUND/AIMS: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is essential for the diagnosis of pancreatic cancer. The feasibility of comprehensive genomic profiling (CGP) using samples obtained by EUS-TA has been under recent discussion. This study aimed to evaluate the utility of EUS-TA for CGP in a clinical setting. METHODS: CGP was attempted in 178 samples obtained from 151 consecutive patients with pancreatic cancer at the Aichi Cancer Center between October 2019 and September 2021. We evaluated the adequacy of the samples for CGP and determined the factors associated with the adequacy of the samples obtained by EUS-TA retrospectively. RESULTS: The overall adequacy for CGP was 65.2% (116/178), which was significantly different among the four sampling methods (EUS-TA vs. surgical specimen vs. percutaneous biopsy vs. duodenal biopsy, 56.0% [61/109] vs. 80.4% [41/51] vs. 76.5% [13/17] vs. 100.0% [1/1], respectively; p=0.022). In a univariate analysis, needle gauge/type was associated with adequacy (22 G fine-needle aspiration vs. 22 G fine-needle biopsy [FNB] vs. 19 G-FNB, 33.3% (5/15) vs. 53.5% (23/43) vs. 72.5% (29/40); p=0.022). The sample adequacy of 19 G-FNB for CGP was 72.5% (29/40), and there was no significant difference between 19 G-FNB and surgical specimens (p=0.375). CONCLUSION: To obtain adequate samples for CGP with EUS-TA, 19 G-FNB was shown to be the best in clinical practice. However, 19 G-FNB was not still sufficient, so further efforts are required to improve adequacy for CGP.

Utility of forward-view endoscopic ultrasound in fine-needle aspiration in patients with a surgically altered upper gastrointestinal anatomy.

BACKGROUND/AIMS: Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) using oblique-view EUS in patients with a surgically altered anatomy (SAA) of the upper gastrointestinal tract is limited because of difficult scope insertion due to the disturbed anatomy. This study aimed to investigate the efficiency of forward-view (FV)-EUS in performing FNA in patients with a SAA. METHODS: We retrospectively investigated 32 patients with a SAA of the upper gastrointestinal tract who visited Aichi Cancer Center Hospital in Nagoya, Japan, between January 2014 and December 2020. We performed-upper gastrointestinal EUS-FNA using FV-EUS combined with fluoroscopic imaging to confirm tumor recurrence or to make a decision before chemotherapy or after a failure of diagnosis by radiology. RESULTS: We successfully performed EUS-FNA in all studied patients (100% technical success), with the specificity, sensitivity, and accuracy of 100%, 87.5%, and 87.8%, respectively, with no complications. CONCLUSION: EUS-FNA using FV-EUS combined with fluoroscopic imaging is an effective and safe technique for tissue acquisition in patients with a SAA.

Artificial intelligence using deep learning analysis of endoscopic ultrasonography images for the differential diagnosis of pancreatic masses.

BACKGROUND : There are several types of pancreatic mass, so it is important to distinguish between them before treatment. Artificial intelligence (AI) is a mathematical technique that automates learning and recognition of data patterns. This study aimed to investigate the efficacy of our AI model using endoscopic ultrasonography (EUS) images of multiple types of pancreatic mass (pancreatic ductal adenocarcinoma [PDAC], pancreatic adenosquamous carcinoma [PASC], acinar cell carcinoma [ACC], metastatic pancreatic tumor [MPT], neuroendocrine carcinoma [NEC], neuroendocrine tumor [NET], solid pseudopapillary neoplasm [SPN], chronic pancreatitis, and autoimmune pancreatitis [AIP]). METHODS : Patients who underwent EUS were included in this retrospective study. The included patients were divided into training, validation, and test cohorts. Using these cohorts, an AI model that can distinguish pancreatic carcinomas from noncarcinomatous pancreatic lesions was developed using a deep-learning architecture and the diagnostic performance of the AI model was evaluated. RESULTS : 22 000 images were generated from 933 patients. The area under the curve, sensitivity, specificity, and accuracy (95 %CI) of the AI model for the diagnosis of pancreatic carcinomas in the test cohort were 0.90 (0.84-0.97), 0.94 (0.88-0.98), 0.82 (0.68-0.92), and 0.91 (0.85-0.95), respectively. The per-category sensitivities (95 %CI) of each disease were PDAC 0.96 (0.90-0.99), PASC 1.00 (0.05-1.00), ACC 1.00 (0.22-1.00), MPT 0.33 (0.01-0.91), NEC 1.00 (0.22-1.00), NET 0.93 (0.66-1.00), SPN 1.00 (0.22-1.00), chronic pancreatitis 0.78 (0.52-0.94), and AIP 0.73 (0.39-0.94). CONCLUSIONS : Our developed AI model can distinguish pancreatic carcinomas from noncarcinomatous pancreatic lesions, but external validation is needed.

Effectiveness and Prognostic Factors of Everolimus in Patients with Pancreatic Neuroendocrine Neoplasms.

Objective The effectiveness of everolimus for the management of pancreatic neuroendocrine neoplasms (PNENs), including the G3/NEC types, remains unclear. We therefore investigated the effectiveness of the drug for the management of PNENs. Methods We analyzed the progression-free survival (PFS) and overall survival (OS) associated with everolimus and factors influencing the PFS and OS. Results One hundred patients were evaluated. The PFS associated with the G1/G2 types tended to be significantly longer than that associated with the G3/NEC types [hazard ratio (HR), 0.45; p=0.005]. A multivariate analysis showed that the significant factors influencing the PFS were age (<65 years old; HR, 0.44; p=0.002), grade (G1/G2; HR, 0.42; p=0.006), everolimus treatment line (≤2nd; HR, 0.55; p=0.031), and presence of treatment with metformin (yes; HR, 0.29; p=0.044). The median OS was 63.8 months. In the multivariate analysis, the significant factors influencing the OS were grade (G1/G2; HR, 0.21; p<0.001), volume of liver metastasis (≤25%; HR, 0.27; p<0.001), everolimus treatment line (≤2nd; HR, 0.27; p<0.001), and presence of primary tumor resection (yes; HR, 0.33; p=0.005). Conclusion The effectiveness of everolimus in the management of G3/NEC types and prognoses tended to be poorer than those associated with the G1/G2 types. Everolimus combined with metformin and early-line treatment with everolimus may be effective for managing advanced PNENs.

Clinical Outcomes of Everolimus Rechallenge in Patients with Pancreatic Neuroendocrine Neoplasms with No Other Treatment Options.

BACKGROUND: The clinical outcomes of everolimus rechallenge in patients with pancreatic neuroendocrine neoplasms (PNENs) are unknown. This study aimed to investigate the treatment outcomes and safety of everolimus rechallenge treatment with PNENs. METHODS: Clinical data of everolimus-treated patients with PNENs at two institutions were collected. Patients who underwent everolimus rechallenge were included in the study. We analyzed the progression-free survival (PFS) and treatment response associated with everolimus rechallenge and the adverse events. RESULTS: Between 2008 and 2020, 117 patients received initial treatment with everolimus, of which 14 patients received everolimus rechallenge. With regard to the grade of PNENs, there were 2 cases of G1, 11 cases of G2, and 1 case of G3. The median rechallenge PFS was 5.7 months. The objective response rate was 21.4%. the disease control rate was 71.4%. The only major grade 3 or 4 adverse event was neutropenia (n = 1, 7.1%). No other severe adverse event was observed. CONCLUSION: The outcomes and safety of everolimus rechallenge were verified, and it was deemed an acceptable treatment. Everolimus rechallenge may provide a new drug therapy for patients with advanced PNENs for whom no other drug treatment option is available.

B2 puncture with forward-viewing EUS simplifies EUS-guided hepaticogastrostomy (with video).

Background and Objectives: EUS-guided hepaticogastrostomy (EUS-HGS) is in widespread use; however, there are few dedicated devices. The B2 route is technically easier than the B3 route for guidewire insertion, dilation, and stenting but if performed with conventional oblique-viewing (OV) EUS, B2 puncture can cause transesophageal puncture and severe adverse events. The aim of this study was to assess the efficacy of forward-viewing (FV) EUS, which we have developed to improve safety for B2 puncture in EUS-HGS (B2-EUS-HGS). Patients and Methods: This single-center retrospective study included 61 consecutive patients who underwent B2-EUS-HGS with FV between February 2020 and March 2021 at Aichi Cancer Center, Japan. The patients were prospectively enrolled, and clinical data were retrospectively collected for these 61 cases. Results: The overall technical success rate of EUS-HGS was 98.3% (60/61). The rate of EUS-HGS with FV was 95.0% (58/61) after three cases converted to OV, and that of B2-EUS-HGS with FV was 88.5% (54/61). The early adverse event rate was 6.5% (4/61). There were no instances of transesophageal puncture. Median procedure time was 24 min (range, 8-70), and no patient required cautery dilation. Conclusions: B2-EUS-HGS can be performed safely using FV, without transesophageal puncture, and supportability of the device is improved as FV is coaxial with the guidewire. FV was efficacious in B2-EUS-HGS, which shows promise for clinical application in the future.

Endoscopic Management of Adenomas in the Ileal Pouch and the Rectal Remnant after Surgical Treatment in Familial Adenomatous Polyposis.

In patients with familial adenomatous polyposis (FAP), adenomas and even carcinomas may develop in the rectal remnant and the ileal pouch after surgical treatment. The aim of this study was to evaluate the outcome of endoscopic management in patients with FAP. The main outcome measurements were the appearance of secondary cancer, complications, and the need for additional surgery. Thirty-four FAP patients with Kock's continent ileostomy (Kock) (n = 3), ileorectal anastomosis (IRA) (n = 12), and ileal pouch-anal anastomosis (IPAA) (n = 19) were identified. The median follow-up period of endoscopic surveillance was 11.5 years for pouch patients (Kock + IPAA) and 21.7 years for IRA. Metachronous adenomas appeared in 32 patients (94.1%). In pouch patients, a total of 120 treatments were given to 20 patients, and 12 sessions of delayed bleeding (10%) occurred, which was significantly higher compared to IRA patients, with 0 sessions (p < 0.001). In IRA patients, a total of 169 treatments were given to 11 patients, with one case of perforation. No adenocarcinoma has developed since the start of endoscopic surveillance. Regular endoscopic surveillance and treatment are feasible and safe. However, in pouch patients, one must be cautious about delayed bleeding in the treatment of adenomas.

HOPS-R01 phase II trial evaluating neoadjuvant S-1 therapy for resectable pancreatic adenocarcinoma.

Although neoadjuvant therapy (Nac) is recommended for high-risk resectable pancreatic cancer (R-PDAC), evidence regarding specific regimes is scarce. This report aimed to investigate the efficacy of S-1 Nac for R-PDAC. In a multicenter phase II trial, we investigated the efficacy of Nac S-1 (an oral fluoropyrimidine agent containing tegafur, gimeracil, and oteracil potassium) in R-PDAC patients. The protocol involved two cycles of preoperative S-1 chemotherapy, followed by surgery, and four cycles of postoperative S-1 chemotherapy. Two-year progression-free survival (PFS) rates were the primary endpoint. Overall survival (OS) rates and median survival time (MST) were secondary endpoints. Forty-nine patients were eligible, and 31 patients underwent resection following Nac, as per protocol (31/49; 63.3%). Per-protocol analysis included data from 31 patients, yielding the 2-year PFS rate of 58.1%, and 2-, 3-, and 5-year OS rates of 96.8%, 54.8%, and 44.0%, respectively. MST was 49.2 months. Intention-to-treat analysis involved 49 patients, yielding the 2-year PFS rate of 40.8%, and the 2-, 3-, and 5-year OS rates of 87.8%, 46.9%, and 33.9%, respectively. MST was 35.5 months. S-1 single regimen might be an option for Nac in R-PDAC; however, the high drop-out rate (36.7%) was a limitation of this study.

Detection rate of endoscopic ultrasound and computed tomography in diagnosing pancreatic neuroendocrine neoplasms including small lesions: A multicenter study.

BACKGROUND/PURPOSE: The detection ability and role of different imaging modalities to detect pancreatic neuroendocrine neoplasms (PNENs) including small lesions is unclear. This study aimed to compare the ability of endoscopic ultrasound (EUS) and computed tomography (CT) to detect PNENs. METHODS: Data of patients who underwent EUS and contrast-enhanced CT and were diagnosed with PNENs were analyzed. The detection rates of pancreatic lesions with EUS and CT based on tumor size and influencing factors were investigated. RESULTS: For 256 PNEN lesions, the detection rate of EUS was better than that of CT (94.5% vs 86.3%; P < .001). EUS was significantly superior to CT for PNENs ≤5 mm (58.3% vs 16.7%; P = .006) and 5-10 mm (97.7% vs 79.5%; P = .008). There was no significant difference in the detection rate between EUS and CT for PNENs >10 mm (98.4% vs 96.4%; P = .375). Size (≤5 mm) and insulinoma were independent factors associated with poor EUS and CT detection rates. CONCLUSIONS: Endoscopic ultrasound exhibited better detection ability than CT, with an excellent detection rate for PNENs >5 mm, except for insulinomas. CT could detect PNENs >10 mm, which are amenable to treatment.

Endoscopic ultrasound-guided portal vein coiling: troubleshooting interventional endoscopic ultrasonography.

Endoscopic ultrasound (EUS)-guided hepaticogastrostomy (HGS) is widely performed not only as an alternative to transpapillary biliary drainage, but also as primary drainage for malignant biliary obstruction. For anatomical reasons, this technique carries an unavoidable risk of mispuncturing intrahepatic vessels. We report a technique for troubleshooting EUS-guided portal vein coiling to prevent bleeding from the intrahepatic portal vein after mispuncture during interventional EUS. EUS-HGS was planned for a 59-year-old male patient with unresectable pancreatic cancer. The dilated bile duct (lumen diameter, 2.8 mm) was punctured with a 19-gauge needle, and a guidewire was inserted. After bougie dilation, the guidewire was found to be inside the intrahepatic portal vein. Embolizing coils were placed to prevent bleeding. Embolization coils were successfully inserted under stabilization of the catheter using a double-lumen cannula with a guidewire. Following these procedures, the patient was asymptomatic. Computed tomography performed the next day revealed no complications.

Utility of stent-in-stent technique in management of post-pancreatitis splenic abscess using forward-viewing echoendoscope.

Highlight Elshair and colleagues describe a novel technique which could be applied for drainage of any paragastric fluid collection, including pseudocyst and abscess. In comparison to the oblique-view echoendoscope, the forward-viewing echoendoscope allows concurrent stent-in-stent placement over the same axis. Double-pit stent deployment inside the metal stent prevents bleeding and metallic-stent kinking.

High-Resolution Probe-Based Confocal Laser Endomicroscopy for Diagnosing Biliary Diseases.

Probe-based confocal laser endomicroscopy is an endoscopic technique that enables in vivo histological evaluation using fluorescent pigment. The ability to diagnostically differentiate between benign and malignant biliary disease using the "CholangioFlexTM", a dedicated biliary device, has been reported. However, the Miami and Paris classifications, used as diagnostic criteria, mainly evaluate findings in the submucosa, and visualizing the epithelium as the main site of lesions remains difficult. To address this problem, we verified the imaging findings and diagnostic ability of three types of probes: CholangioFlexTM, GastroFlexTM, and AlveoFlexTM. With GastroFlexTM, the clear mucosal epithelium was observed, and differential diagnoses as benign/malignant could be made based on epithelial findings. GastroFlexTM may be a good first-choice probe for probe-based confocal laser endomicroscopy of biliary diseases, and a new diagnostic classification based on bile duct epithelial findings may provide useful criteria independent of the Miami or Paris classifications.