Background/Aims: Post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) is the most common and serious complication of endoscopic retrograde cholangiopancreatography. To prevent this event, a unique precutting method, termed opening window fistulotomy, was performed in patients with a large infundibulum as the primary procedure for biliary cannulation, whereby a suprapapillary laid-down H-shaped incision was made without touching the orifice. This study aimed to assess the safety and feasibility of this novel technique. Methods: One hundred and ten patients were prospectively enrolled in this study. Patients with a papillary roof size ≥10 mm underwent opening window fistulotomy for primary biliary access. In addition, the incidence of complications and success rate of biliary cannulation were evaluated. Results: The median size of the papillary roof was 6 mm (range, 3–20 mm). Opening window fistulotomy was performed in 30 patients (27.3%), none of whom displayed PEP. Duodenal perforation was recorded in one patient (3.3%), which was resolved by conservative treatment. The cannulation rate was high (96.7%, 29/30 patients). The median duration of biliary access was 8 minutes (range, 3–15 minutes). Conclusions Opening window fistulotomy demonstrated its feasibility for primary biliary access by achieving great safety with no PEP complications and a high success rate for biliary cannulation.

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). Conclusions 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.

Benign biliary stricture (BBS) is a complication of chronic pancreatitis (CP). Despite endoscopic biliary stenting, some patients do not respond to treatment, and they experience recurrent cholangitis. We report two cases of CP with refractory BBS treated using endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) fistula creation. A 50-year-old woman and a 60-year-old man both presented with obstructive jaundice secondary to BBS due to alcoholic CP. They underwent repeated placement of a fully covered self-expandable metal stent for biliary strictures. However, the strictures persisted, causing repeated episodes of cholangitis. Therefore, an EUS-CDS was performed. The stents were eventually removed and the patients became stent-free. These fistulas have remained patent without cholangitis for more than 2.5 years. Fistula creation using EUS-CDS is an effective treatment option for BBS.

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.

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.

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. Conclusions 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.

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.