Background/Aims: In patients undergoing endoscopic extraction of common bile duct stones (CBDs) and subsequent cholecystectomy, CBDs sometimes recur during the preoperative and perioperative periods. In this study, the incidence and risk factors for CBDs recurrence were investigated. Methods: A total of 245 patients (mean age: 66 years; 138 men) who underwent cholecystectomy within 180 days of CBDs extraction between October 2017 and June 2023 were included. Recurrence was defined as the detection of the CBDs during the preoperative or perioperative period using imaging modalities such as computed tomography or re-endoscopic retrograde cholangiopancreatography, regardless of the presence of cholangitis. Results: CBDs recurrence occurred in 4.1% of the patients (10/245). The median time to recurrence was 40 days. Preoperative recurrence was observed in nine patients, and only one patient had postoperative recurrence. Multivariate analysis identified cystic duct stones as the only significant risk factor for CBDs recurrence (hazard ratio, 15.6; 95% confidence interval, 3.7–66; p<0.001). Conclusions The risk of CBDs recurrence after endoscopic extraction during the pre and perioperative periods is high in patients with cystic duct stones. Prophylactic biliary stenting may be considered in high-risk patients.

Background/Aims: The factors affecting the detection rate of lymphoplasmacytic sclerosing pancreatitis (LPSP) using endoscopic ultrasound-guided tissue acquisition (EUS-TA) in patients with type 1 autoimmune pancreatitis (AIP) have not been thoroughly studied. Therefore, we conducted a retrospective study to identify the predictive factors for histologically detecting level 1 or 2 LPSP using EUS-TA. Methods: Fifty patients with AIP were included in this study, and the primary outcome measures were the predictive factors for histologically detecting level 1 or 2 LPSP using EUS-TA. Results: Multivariate analysis identified the use of fine needle biopsy (FNB) needles as a significant predictive factor for LPSP detection (odds ratio, 15.1; 95% confidence interval, 1.62–141; ¬¬p=0.017). The rate of good-quality specimens (specimen adequacy score ≥4) was significantly higher for the FNB needle group than for the fine needle aspiration (FNA) needle group (97% vs. 56%; p<0.01), and the FNB needle group required significantly fewer needle passes than the FNA needle group (median, 2 vs. 3; p<0.01). Conclusions The use of FNB needles was the most important factor for the histological confirmation of LPSP using EUS-TA in patients with type 1 AIP.

Background/Aims: The factors affecting the detection rate of lymphoplasmacytic sclerosing pancreatitis (LPSP) using endoscopic ultrasound-guided tissue acquisition (EUS-TA) in patients with type 1 autoimmune pancreatitis (AIP) have not been thoroughly studied. Therefore, we conducted a retrospective study to identify the predictive factors for histologically detecting level 1 or 2 LPSP using EUS-TA. Methods: Fifty patients with AIP were included in this study, and the primary outcome measures were the predictive factors for histologically detecting level 1 or 2 LPSP using EUS-TA. Results: Multivariate analysis identified the use of fine needle biopsy (FNB) needles as a significant predictive factor for LPSP detection (odds ratio, 15.1; 95% confidence interval, 1.62–141; ¬¬p=0.017). The rate of good-quality specimens (specimen adequacy score ≥4) was significantly higher for the FNB needle group than for the fine needle aspiration (FNA) needle group (97% vs. 56%; p<0.01), and the FNB needle group required significantly fewer needle passes than the FNA needle group (median, 2 vs. 3; p<0.01). Conclusions The use of FNB needles was the most important factor for the histological confirmation of LPSP using EUS-TA in patients with type 1 AIP.

Background/Aims: The factors affecting the detection rate of lymphoplasmacytic sclerosing pancreatitis (LPSP) using endoscopic ultrasound-guided tissue acquisition (EUS-TA) in patients with type 1 autoimmune pancreatitis (AIP) have not been thoroughly studied. Therefore, we conducted a retrospective study to identify the predictive factors for histologically detecting level 1 or 2 LPSP using EUS-TA. Methods: Fifty patients with AIP were included in this study, and the primary outcome measures were the predictive factors for histologically detecting level 1 or 2 LPSP using EUS-TA. Results: Multivariate analysis identified the use of fine needle biopsy (FNB) needles as a significant predictive factor for LPSP detection (odds ratio, 15.1; 95% confidence interval, 1.62–141; ¬¬p=0.017). The rate of good-quality specimens (specimen adequacy score ≥4) was significantly higher for the FNB needle group than for the fine needle aspiration (FNA) needle group (97% vs. 56%; p<0.01), and the FNB needle group required significantly fewer needle passes than the FNA needle group (median, 2 vs. 3; p<0.01). Conclusions The use of FNB needles was the most important factor for the histological confirmation of LPSP using EUS-TA in patients with type 1 AIP.

Background/Aims: Endoscopic biliary drainage using self-expandable metallic stents (SEMSs) for malignant biliary strictures occasionally induces acute cholecystitis (AC). This study evaluated the efficacy of prophylactic gallbladder stents (GBS) during SEMS placement. Methods: Among 158 patients who underwent SEMS placement for malignant biliary strictures between January 2018 and March 2023, 30 patients who attempted to undergo prophylactic GBS placement before SEMS placement were included. Results: Technical success was achieved in 21 cases (70.0%). The mean diameter of the cystic duct was more significant in the successful cases (6.5 mm vs. 3.7 mm, p<0.05). Adverse events occurred for 7 patients (23.3%: acute pancreatitis in 7; non-obstructive cholangitis in 1; perforation of the cystic duct in 1 with an overlap), all of which improved with conservative treatment. No patients developed AC when the GBS placement was successful, whereas 25 of the 128 patients (19.5%) without a prophylactic GBS developed AC during the median follow-up period of 357 days (p=0.043). In the multivariable analysis, GBS placement was a significant factor in preventing AC (hazard ratio, 0.61; 95% confidence interval, 0.37–0.99; p=0.045). Conclusions GBS may contribute to the prevention of AC after SEMS placement for malignant biliary strictures.

Objective: Practical applications of nerve decompression using neurosurgical robots remain unexplored. Our ongoing research and development initiatives, utilizing industrial robots, aim to establish a secure and efficient neurosurgical robotic system. The principal objective of this study was to automate bone grinding, which is a pivotal component of neurosurgical procedures. Methods: To achieve this goal, we integrated an endoscope system into a manipulator and conducted precision bone machining using a neurosurgical drill, recording the grinding resistance values across 3 axes. Our study encompassed 2 core tasks: linear grinding, such as laminectomy, and cylindrical grinding, such as foraminotomy, with each task yielding unique measurement data. Results: In linear grinding, we observed a proportional increase in grinding resistance values in the machining direction with acceleration. This observation suggests that 3-axis resistance measurements are a valuable tool for gauging and predicting deep cortical penetration. However, problems occurred in cylindrical grinding, and a significant error of 10% was detected. The analysis revealed that multiple factors, including the tool tip efficiency, machining speed, teaching methods, and deflection in the robot arm and jig joints, contributed to this error. Conclusion We successfully measured the resistance exerted on the tool tip during bone machining with a robotic arm across 3 axes. The resistance ranged from 3 to 8 Nm, with the measurement conducted at a processing speed approximately twice that of manual surgery performed by a surgeon. During the simulation of foraminotomy under endoscopic grinding conditions, we encountered a -10% error margin.