Tsuyoshi Mukai

Objectives: A sufficient amount of cancer tissue for next‐generation sequencing (NGS) is difficult to obtain from patients with unresectable cholangiocarcinoma. We evaluated whether bile cell block (CB) samples provide a DNA source of sufficient quantity and quality for NGS compared with surgical specimens. Methods: NGS results of paired bile CB and surgical specimens from 14 patients were compared. Results: Median number of malignant cells on one glass slide of CB specimen was 50. Although median DNA concentration and amount of extracted DNA were significantly lower in the CB than those in the surgical specimens, NGS success rate did not differ significantly (CB, 64%; surgical specimen, 86%). In a pair‐wise comparison of eight patients with successful NGS of both bile CB and surgical specimens, median gene matching rate was 99%, and median coverage rate of surgical genes based on CB genes was 100%. The presence of ≥ 30 malignant cells on a single slide was identified as a practical indicator of successful NGS of CB using receiver operating characteristic curve, and this threshold increased the NGS success rate to 80%. Conclusions: As bile CB is easy to prepare in general hospitals, bile cell‐based NGS may help address the difficulty of obtaining surgical NGS samples for cholangiocarcinoma.

Objectives: Radiation dose reduction is an important consideration in ERCP. However, the low radiation dose compromises image quality. This study evaluated the utility of radiation‐reduction settings in a fluoroscopic system. Methods: Three fluoroscopic settings (high‐dose, low‐dose, and low‐dose with a new image processor; SCORE PRO Advance [ SPA ]) were compared. Results: From 2024 to 2025, high‐dose (124‐patients), low‐dose (110‐patients), and SPA (135‐patients) were evaluated. There were no significant differences in baseline characteristics of patients and the details of the ERCP procedure, except for sex distribution. High‐dose (skin dose [SD]:72.6 [mGy]/dose area product [DAP]:233.9 [dGy・cm ² ]) showed a significantly higher radiation dose than low‐dose (40.0/121.9) and SPA (32.5/109.4) ( p < 0.01). For ERCP, procedure time was significantly longer in low‐dose than in SPA (22 vs. 17 min; p = 0.04). In multivariate analysis, high‐dose (SD: odds ratio [OR] 31.6, p < 0.01/DAP:OR17.7, p < 0.01) and long ERCP procedure time (OR3.33, p < 0.01/OR3.90, p < 0.01) were related to the high radiation dose exposure. SPA was independently associated with shorter ERCP procedure time (OR 0.63; p = 0.04). Conclusions: SPA and low‐dose provided comparable reductions in radiation exposure. Furthermore, SPA was associated with a shorter ERCP time than a low dose, possibly because of improved image quality. However, until fluoroscopic systems are upgraded to incorporate SPA, low‐dose may provide clinical utility for reducing radiation exposure. Trial Registration: ClinicalTrials.gov identifier: UMIN000061448

Background and Aims: Endoscopic retrograde cholangiopancreatography (ERCP), the standard procedure for common bile duct (CBD) stones (CBDS) removal, carries a risk of post‐ERCP pancreatitis (PEP). We compared PEP‐related factors between asymptomatic and symptomatic CBDS cases. Methods: A retrospective cohort study was conducted on 367 patients who underwent ERCP for CBDS. To adjust for baseline differences, propensity score matching (PSM) was performed, yielding 170 matched patients (85 asymptomatic and 85 symptomatic groups) for comparative analysis of PEP‐related factors. Results: Baseline differences in the proportion of patients with American Society of Anesthesiologists‐Physical Status (≥ 3) cases, CBD diameter, and CBDS size were eliminated after PSM. The asymptomatic group had a significantly longer ERCP procedure time (20 vs. 18‐min, p = 0.02) and a higher incidence of PEP compared to the symptomatic group (11.8% vs. 1.2%, p = 0.01). Multivariate analysis confirmed that asymptomatic CBDS cases (odds ratio [OR]: 9.37, 95% confidence interval [CI]: 1.13–77.6, p = 0.0381) and prolonged procedure time (> 26 min, OR: 5.29, 95% CI: 1.26–22.3, p = 0.0231) were independent risk factors for PEP. Conclusions: ERCP procedures performed for asymptomatic CBDS cases are associated with a higher risk of PEP. The decision to perform ERCP in asymptomatic CBDS cases should carefully consider the PEP risk factors of the patient. Trial Registration: UMIN000055951

Background: Mapping biopsy (MB) can evaluate superficial ductal spread (SDS) through the histopathological diagnosis of cholangiocarcinoma, enabling the selection of an appropriate surgical procedure. This retrospective study evaluated the efficacy of MB using a novel sheath system in distal cholangiocarcinoma (dCCA) cases.Methods: A total of 199 cholangiocarcinoma cases underwent preoperative diagnosis. Among them, 40, 21, and 26 cases underwent direct, sheath, and peroral cholangioscopy (POCS) MB, respectively, for dCCA. Each group was compared regarding their technical success rate and the diagnostic accuracy for SDS.Results: Although all cases achieved technical success, the median procedure time of POCS (48‐min) tended to be longer than direct (33‐min) and sheath MB (30‐min) (p overall = .092). Diagnostic specificity and accuracy were significantly higher in the sheath group (95.2%, 95.2%) compared to the direct (71.0%, 70.0%) and POCS (60.9%, 57.7%) MB groups (p overall = .019 and .0094). Multivariate analysis revealed that the sheath MB group was an independent significant factor for the accurate margin diagnosis (OR 0.11; 95% CI: 0.01–0.86, p = .0358).Conclusions: The sheath MB method provided the most accurate histopathological diagnosis of SDS in dCCA. To obtain a larger tissue sample and avoid tumor cell contamination, sheath MB is worth performing to assess the accuracy of the preoperative SDS diagnosis.

Postoperative pancreatic fistulas (POPFs) are common adverse events that occur after pancreatic surgery. Endoscopic ultrasonography (EUS)-guided drainage (EUS-D) is a first-line treatment, similar to that for pancreatic fluid collection (PFCs) after acute pancreatitis. However, some POPFs do not develop fluid collections depending on the presence or location of the surgical drain, whereas others develop fluid collections, such as postoperative fluid collections (POPFCs). Although POPFCs are similar to PFCs, the strategy and modality for POPF management need to be modified according to the presence of fluid collections, surgical drains, and surgical type. As discussed for PFCs, the indications, timing, and selection of interventions or stents for EUS-D have not been fully elucidated for POPFs. In this review, we discuss the management of POPFs and POPFCs in comparison with PFCs due to acute pancreatitis and summarize the topics that should be addressed in future studies.

Background/Aims: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) using a 19-gauge needle is an efficient sampling method for the diagnosis of lymphadenopathy. This study compared 19-gauge conventional and Franseen needles for the diagnosis of lymphadenopathy and classification of malignant lymphoma (ML).Methods: Patient characteristics, number of needle passes, puncture route, sensitivity, specificity, and accuracy of cytology/histology for lymphadenopathy were analyzed in patients diagnosed with lymphadenopathy by EUS-FNA using conventional or Franseen needles.Results: Between 2012 and 2022, 146 patients met the inclusion criteria (conventional [n=70] and Franseen [n=76]). The median number of needle passes was significantly lower in the conventional group than in the Franseen group (3 [1–6] vs. 4 [1–6], p=0.023). There were no significant differences in cytological/histological diagnoses between the two groups. For ML, the immunohistochemical evaluation rate, sensitivity of flow cytometry, and cytogenetic assessment were not significantly different in either group. Bleeding as adverse events (AEs) were observed in three patients in the Franseen group.Conclusions: Both the 19-gauge conventional and Franseen needles showed high accuracy in lymphadenopathy and ML classification. Considering sufficient tissue collection and the avoidance of AEs, the use of 19-gauge conventional needles seems to be a good option for the diagnosis of lymphadenopathy.

The identification of anticancer therapies using next-generation sequencing (NGS) is necessary for the treatment of cholangiocarcinoma. NGS can be easily performed when cell blocks (CB) are obtained from bile stored overnight. We compared NGS results of paired CB and surgically resected specimens (SRS) from the same cholangiocarcinoma cases. Of the prospectively collected 64 bile CBs from 2018 to 2023, NGS was performed for three cases of cholangiocarcinoma that could be compared with the SRS results. The median numbers of DNA and RNA reads were 95,077,806 [CB] vs. 93,161,788 [SRS] and 22,101,328 [CB] vs. 24,806,180 [SRS], respectively. We evaluated 588 genes and found that almost all genetic alterations were attributed to single-nucleotide variants, insertions/deletions, and multi-nucleotide variants. The coverage rate of variants in SRS by those found in CB was 97.9–99.2%, and the coverage rate of SRS genes by CB genes was 99.6–99.7%. The NGS results of CB fully covered the variants and genetic alterations observed in paired SRS samples. As bile CB is easy to prepare in general hospitals, our results suggest the potential use of bile CB as a novel method for NGS-based evaluation of cholangiocarcinoma.

Background: Extracorporeal shock wave lithotripsy (ESWL) is a common treatment for pancreatic stones in chronic pancreatitis. In contrast, peroral pancreatoscopy-guided lithotripsy (POPS-L) remains underexplored, with limited comparative studies to ESWL. This study compared the treatment outcomes of disposable POPS-L tools and ESWL for pancreatic stones. Methods: A retrospective analysis was conducted on 66 patients who had undergone pancreatic stone treatment at three institutions between 2006 and 2022. The treatment outcomes of POPS-L and ESWL were compared. Results: This study included 19 and 47 patients who had undergone POPS-L and ESWL, respectively. In a comparison between POPS-L and ESWL, the stone clearance rates were 78.9% vs. 70.2% (p = 0.55), while the procedure-related complication rates were 21% vs. 6.3% (p = 0.09). The median total session counts were 1 vs. 5 (p < 0.01). The cumulative stone recurrence rates were comparable in both groups. Multivariate analysis revealed no significant factors influencing the stone clearance rates, and the choice between POPS-L and ESWL did not affect the stone clearance rates. Conclusions: POPS-L and ESWL exhibited comparable treatment outcomes in terms of stone clearance, complications, and recurrence rates. Furthermore, POPS-L is advantageous due to the need for fewer sessions to achieve pancreatic stone clearance.