Side-by-side placement of fully covered metal stents versus conventional 7F plastic stents in malignant hilar biliary obstruction: Prospective randomized controlled trial.

OBJECTIVES: We aimed to evaluate the efficacy and safety of metal stents compared with plastic stents when bilateral side-by-side stents were deployed for malignant hilar biliary obstruction (MHBO). METHODS: Fifty patients with unresectable advanced MHBO were randomly assigned to the metal stent (MS, n = 25) or plastic stent group (PS, n = 25). Fully covered self-expandable metal stents with 6 mm diameter and plastic stents with either 7F straight or double pigtail were used for MS and PS groups, respectively. Time to recurrent biliary obstruction (TRBO) was evaluated as the primary outcome. RESULTS: Both groups had 100% technical success rates; 88% and 76% of clinical success rates were obtained in MS and PS, respectively. Although stent migrations were more frequent in MS than PS (48% vs. 16%, P = 0.02), the mean TRBO was significantly longer in MS (190 days; 95% confidence interval [CI] 121-260 days vs. 96 days; 95% CI 50-141 days, P = 0.02). The placement of plastic stents (hazard ratio 2.42; 95% CI 1.24-4.73; P = 0.01) was the only significant risk factor associated with TRBO in multivariable analysis. The rates of adverse events were similar between the two groups (difference 0%; 95% CI -25% to 25%; P > 0.99). CONCLUSIONS: During bilateral side-by-side deployment in MHBO, the use of metal stents appears to be preferable to plastic stents in terms of TRBO, despite a higher frequency of stent migration.

Usefulness of Liquid-Based Cytology in Diagnosing Biliary Tract Cancer Compared to Conventional Smear and Forceps Biopsy.

BACKGROUND/AIMS: Liquid-based cytology (LBC) has been shown to improve the diagnostic efficacy of brush cytology for thyroid, cervical and pancreatic cancer. To evaluate the diagnostic performance of LBC for biliary tract cancer, we compared it with conventional smears and forceps biopsies. METHODS: A retrospective study was conducted of all consecutive patients who underwent brush cytology under ERCP from January 2010 to April 2020. The primary outcome was the diagnostic efficacy of conventional smears and LBC. The difference between the two groups was corrected using inverse probability weighting (IPW). The secondary outcome was the sensitivity and specificity of brush cytology and forceps biopsy. The secondary outcome was evaluated in patients who underwent both methods. RESULTS: Among 162 patients, conventional smears were performed in 70 patients and LBC was performed in 92 patients. In the primary analysis using IPW, the sensitivity of conventional smears and LBC was 56.00% and 78.26% respectively (P = 0.009). The specificity was 100% for both methods. The accuracy was 66.15% for conventional smears and 83.33% for LBC (P = 0.012). In the secondary analysis, the sensitivity of conventional smears versus forceps biopsies was 62.16% versus 78.38% (P = 0.034) and 81.16% for both LBC and forceps biopsies. The specificity of both cytological examination and forceps biopsies was 100%. CONCLUSIONS: Liquid-based cytology demonstrated better sensitivity and accuracy than conventional smears. Moreover, its diagnostic performance was close to that of forceps biopsies.

The effect of nafamostat mesilate infusion after ERCP for post-ERCP pancreatitis.

BACKGROUND: Nafamostat mesilate decreases the incidence of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). However, no studies have administered nafamostat mesilate after ERCP. So we investigated if the infusion of nafamostat mesilate after ERCP can affect the post-ERCP pancreatitis (PEP) in high-risk patients. METHODS: In a tertiary hospital, 350 high-risk patients of PEP were reviewed retrospectively. Among them, 201 patients received nafamostat mesilate after ERCP. Patient-related and procedure-related risk factors for PEP were collected. We performed a propensity score matching to adjust for the significant different baseline characteristics. The incidence and severity of PEP were evaluated according to the infusion of nafamostat mesilate. The risk factors of PEP were also analyzed by multivariate logistic regression. RESULTS: The baseline characteristics were not different after the matching. The PEP rate (17.4% vs. 10.3%, P = 0.141) was insignificant. Among the PEP patients, mild PEP was significantly higher in the nafamostat mesilate group (85.7% vs. 45.5%, P = 0.021). Only one patient in the nafamostat mesilate group developed severe PEP. Although young age (odds ratio [OR] 3.60, 95% CI 1.09-11.85, P = 0.035) was a risk factor, nafamostat mesilate (odds ratio [OR] 0.30, 95% CI 0.09-0.98, P = 0.047) was a protective factor for moderate to severe PEP. CONCLUSIONS: The administration of nafamostat mesilate after ERCP in high-risk patients was not effective in preventing PEP, but may attenuate the severity of PEP.

Comparison between FOLFIRINOX and gemcitabine plus nab-paclitaxel including sequential treatment for metastatic pancreatic cancer: a propensity score matching approach.

BACKGROUND: FOLFIRINOX (FFX) and Gemcitabine plus nab-paclitaxel (GnP) have been recommended as the first-line chemotherapy for metastatic pancreatic cancer (mPC). However, the evidence is lacking comparing not only two regimens, but also sequential treatment (FFX-GnP vs. GnP-FFX). METHODS: Data of 528 patients (FFX, n = 371; GnP, n = 157) with mPC were collected retrospectively. Propensity score matching was conducted to alleviate imbalance of the two groups. Overall survival (OS), progression free survival (PFS), and toxicity of patients were analyzed. RESULTS: In the whole population, OS (12.5 months vs. 10.3 months, P = 0.05) and PFS (7.1 months vs. 5.8 months, P = 0.02) were longer in the FFX group before matching and after matching (OS: 11.8 months vs. 10.3 months, P = 0.02; PFS: 7.2 months vs. 5.8 months, P <  0.01). For sequential treatment, OS and PFS showed no significant difference. Interruptions of chemotherapy due to toxicities were more frequent (6.8 vs. 29.3%, P <  0.001) in the GnP group, and cessation of chemotherapy showed a significant association with mortality (z = - 1.94, P = 0.03). CONCLUSIONS: FFX achieved a longer overall survival than GnP in mPC, but not in the comparison for sequential treatment. More frequent adverse events followed by treatment interruptions during GnP might lead to a poor survival outcome. Therefore, FFX would be a better first-line treatment option than GnP for mPC.

Optimal timing of endoscopic retrograde cholangiopancreatography for acute cholangitis associated with distal malignant biliary obstruction.

BACKGROUND: There is a lack of studies regarding the optimal timing for endoscopic retrograde cholangiopancreatography (ERCP) in patients with cholangitis caused by distal malignant biliary obstruction (MBO). This study aims to investigate the optimal timing of ERCP in patients with acute cholangitis associated with distal MBO with a naïve papilla. METHODS: A total of 421 patients with acute cholangitis, associated with distal MBO, were enrolled for this study. An urgent ERCP was defined as being an ERCP performed within 24 h following emergency room (ER) arrival, and early ERCP was defined as an ERCP performed between 24 and 48 h following ER arrival. We evaluated both 30-day and 180-day mortality as primary outcomes, according to the timing of the ERCP. RESULTS: The urgent ERCP group showed the lowest 30-day mortality rate (2.2%), as compared to the early and delayed ERCP groups (4.3% and 13.5%) (P < 0.001). The 180-day mortality rate was lowest in the urgent ERCP group, followed by early ERCP and delayed ERCP groups (39.4%, 44.8%, 60.8%; P = 0.006). A subgroup analysis showed that in both the primary distal MBO group, as well as in the moderate-to-severe cholangitis group, the urgent ERCP had significantly improved in both 30-day and 180-day mortality rates. However, in the secondary MBO and mild cholangitis groups, the difference in mortality rate between urgent, early, and delayed ERCP groups was not significant. CONCLUSIONS: In patients with acute cholangitis associated with distal MBO, urgent ERCP might be helpful in improving the prognosis, especially in patients with primary distal MBO or moderate-to-severe cholangitis.

High platelet-to-lymphocyte ratio is associated with poor prognosis in patients with unresectable intrahepatic cholangiocarcinoma receiving gemcitabine plus cisplatin.

BACKGROUND: Several systemic inflammatory response (SIR) markers, including platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and albumin-to-globulin ratio (AGR), have emerged as prognostic markers in various cancers. The aim of this study was to explore the impact of SIR markers on the survival outcomes of unresectable intrahepatic cholangiocarcinoma (IHC) patients. METHODS: Patients with histologically confirmed, unresectable IHC treated with gemcitabine plus cisplatin (GP) chemotherapy in a single tertiary hospital from 2012 to 2016 were retrospectively reviewed. Progression-free survival (PFS) and overall survival (OS) were determined using unadjusted Kaplan-Meier and adjusted Cox-proportional-hazards analysis. Time-dependent receiver operating characteristic (ROC) analysis was performed to compare the performance of the SIR markers in predicting OS. RESULTS: A total of 137 patients received a median of six cycles (interquartile range [IQR], 3-11) of GP chemotherapy with a median observation time of 9.9 months (range, 1.8-54.7 months). The median PFS and OS of all patients were 7.8 months and 9.9 months, respectively. Among the SIR markers, high PLR (> 148) and high NLR (> 5) were associated with a short PFS (Hazard ratio [HR] 1.828, P = 0.006; HR 1.738, P = 0.030, respectively) and short OS (HR 2.332, P < 0.001; HR 2.273, P < 0.001, respectively). Low LMR (< 3.5) and low AGR (< 1.2) were associated with a short OS (HR 2.423, P < 0.001; HR 1.768, P = 0.002, respectively). In multivariable cox-regression analysis, high PLR (HR 1.766, P = 0.009) and distant lymph node (LN) metastasis (HR 2.085, P = 0.001) were associated with a short PFS. High PLR (HR 1.856, P = 0.002) was an independent predictor of a short OS, along with distant LN metastasis (HR 1.929; P < 0.001), low LMR (HR 1.691; P = 0.041), and low level of serum albumin (< 3.5 g/dL) (HR 1.632; P = 0.043). Time-dependent ROC analysis revealed that the area under the curve of PLR for predicting overall survival was greater than that of NLR, LMR, and AGR at most time points. CONCLUSIONS: High PLR was an independent prognostic factor of a short PFS and OS in patients with unresectable IHC receiving GP chemotherapy.

A half millimeter thick coplanar flexible battery with wireless recharging capability.

Most of the existing flexible lithium ion batteries (LIBs) adopt the conventional cofacial cell configuration where anode, separator, and cathode are sequentially stacked and so have difficulty in the integration with emerging thin LIB applications, such as smart cards and medical patches. In order to overcome this shortcoming, herein, we report a coplanar cell structure in which anodes and cathodes are interdigitatedly positioned on the same plane. The coplanar electrode design brings advantages of enhanced bending tolerance and capability of increasing the cell voltage by in series-connection of multiple single-cells in addition to its suitability for the thickness reduction. On the basis of these structural benefits, we develop a coplanar flexible LIB that delivers 7.4 V with an entire cell thickness below 0.5 mm while preserving stable electrochemical performance throughout 5000 (un)bending cycles (bending radius = 5 mm). Also, even the pouch case serves as barriers between anodes and cathodes to prevent Li dendrite growth and short-circuit formation while saving the thickness. Furthermore, for convenient practical use wireless charging via inductive electromagnetic energy transfer and solar cell integration is demonstrated.

The High Performance of Crystal Water Containing Manganese Birnessite Cathodes for Magnesium Batteries.

Rechargeable magnesium batteries have lately received great attention for large-scale energy storage systems due to their high volumetric capacities, low materials cost, and safe characteristic. However, the bivalency of Mg(2+) ions has made it challenging to find cathode materials operating at high voltages with decent (de)intercalation kinetics. In an effort to overcome this challenge, we adopt an unconventional approach of engaging crystal water in the layered structure of Birnessite MnO2 because the crystal water can effectively screen electrostatic interactions between Mg(2+) ions and the host anions. The crucial role of the crystal water was revealed by directly visualizing its presence and dynamic rearrangement using scanning transmission electron microscopy (STEM). Moreover, the importance of lowering desolvation energy penalty at the cathode-electrolyte interface was elucidated by working with water containing nonaqueous electrolytes. In aqueous electrolytes, the decreased interfacial energy penalty by hydration of Mg(2+) allows Birnessite MnO2 to achieve a large reversible capacity (231.1 mAh g(-1)) at high operating voltage (2.8 V vs Mg/Mg(2+)) with excellent cycle life (62.5% retention after 10000 cycles), unveiling the importance of effective charge shielding in the host and facile Mg(2+) ions transfer through the cathode's interface.

An Electrochemical Cell for Selective Lithium Capture from Seawater.

Lithium (Li) is a core element of Li-ion batteries (LIBs). Recent developments in mobile electronics such as smartphones and tablet PCs as well as advent of large-scale LIB applications including electrical vehicles and grid-level energy storage systems have led to an increase in demand for LIBs, giving rise to a concern on the availability and market price of Li resources. However, the current Lime-Soda process that is responsible for greater than 80% of worldwide Li resource supply is applicable only in certain regions on earth where the Li concentrations are sufficiently high (salt lakes or salt pans). Moreover, not only is the process time-consuming (12-18 months), but post-treatments are also required for the purification of Li. Here, we have devised a location-independent electrochemical system for Li capture, which can operate within a short time period (a few hours to days). By engaging olivine LiFePO4 active electrode that improves interfacial properties via polydopamine coating, the electrochemical cell achieves 4330 times amplification in Li/Na ion selectivity (Li/Na molar ratio of initial solution = 0.01 and Li/Na molar ratio of final electrode = 43.3). In addition, the electrochemical system engages an I(-)/I3(-) redox couple in the other electrode for balancing of the redox states on both electrode sides and sustainable operations of the entire cell. Based on the electrochemical results, key material and interfacial properties that affect the selectivity in Li capture are identified.

Direct Observation of an Anomalous Spinel-to-Layered Phase Transition Mediated by Crystal Water Intercalation.

The phase transition of layered manganese oxides to spinel phases is a well-known phenomenon in rechargeable batteries and is the main origin of the capacity fading in these materials. This spontaneous phase transition is associated with the intrinsic properties of manganese, such as its size, preferred crystal positions, and reaction characteristics, and it is therefore very difficult to avoid. The introduction of crystal water by an electrochemical process enables the inverse phase transition from spinel to a layered Birnessite structure. Scanning transmission electron microscopy can be used to directly visualize the rearrangement of lattice atoms, the simultaneous insertion of crystal water, the formation of a transient structure at the phase boundary, and layer-by-layer progression of the phase transition from the edge. This research indicates that crystal water intercalation can reverse phase transformation with thermodynamically favored directionality.

One-dimensional carbon-sulfur composite fibers for Na-S rechargeable batteries operating at room temperature.

Na-S batteries are one type of molten salt battery and have been used to support stationary energy storage systems for several decades. Despite their successful applications based on long cycle lives and low cost of raw materials, Na-S cells require high temperatures above 300 °C for their operations, limiting their propagation into a wide range of applications. Herein, we demonstrate that Na-S cells with solid state active materials can perform well even at room temperature when sulfur-containing carbon composites generated from a simple thermal reaction were used as sulfur positive electrodes. Furthermore, this structure turned out to be robust during repeated (de)sodiation for ~500 cycles and enabled extraordinarily high rate performance when one-dimensional morphology is adopted using scalable electrospinning processes. The current study suggests that solid-state Na-S cells with appropriate atomic configurations of sulfur active materials could cover diverse battery applications where cost of raw materials is critical.

Wearable textile battery rechargeable by solar energy.

Wearable electronics represent a significant paradigm shift in consumer electronics since they eliminate the necessity for separate carriage of devices. In particular, integration of flexible electronic devices with clothes, glasses, watches, and skin will bring new opportunities beyond what can be imagined by current inflexible counterparts. Although considerable progresses have been seen for wearable electronics, lithium rechargeable batteries, the power sources of the devices, do not keep pace with such progresses due to tenuous mechanical stabilities, causing them to remain as the limiting elements in the entire technology. Herein, we revisit the key components of the battery (current collector, binder, and separator) and replace them with the materials that support robust mechanical endurance of the battery. The final full-cells in the forms of clothes and watchstraps exhibited comparable electrochemical performance to those of conventional metal foil-based cells even under severe folding-unfolding motions simulating actual wearing conditions. Furthermore, the wearable textile battery was integrated with flexible and lightweight solar cells on the battery pouch to enable convenient solar-charging capabilities.

Deep learning-based prediction of Clostridioides difficile infection caused by antibiotics using longitudinal electronic health records.

Clostridioides difficile infection (CDI) is a major cause of antibiotic-associated diarrhea and colitis. It is recognized as one of the most significant hospital-acquired infections. Although CDI can develop severe complications and spores of Clostridioides difficile can be transmitted by the fecal-oral route, CDI is occasionally overlooked in clinical settings. Thus, it is necessary to monitor high CDI risk groups, particularly those undergoing antibiotic treatment, to prevent complications and spread. We developed and validated a deep learning-based model to predict the occurrence of CDI within 28 days after starting antibiotic treatment using longitudinal electronic health records. For each patient, timelines of vital signs and laboratory tests with a 35-day monitoring period and a patient information vector consisting of age, sex, comorbidities, and medications were constructed. Our model achieved the prediction performance with an area under the receiver operating characteristic curve of 0.952 (95% CI: 0.932-0.973) in internal validation and 0.972 (95% CI: 0.968-0.975) in external validation. Platelet count and body temperature emerged as the most important features. The risk score, the output value of the model, exhibited a consistent increase in the CDI group, while the risk score in the non-CDI group either maintained its initial value or decreased. Using our CDI prediction model, high-risk patients requiring symptom monitoring can be identified. This could help reduce the underdiagnosis of CDI, thereby decreasing transmission and preventing complications.

Clinical Significance of Venous Thromboembolism in Patients with Advanced Cholangiocarcinoma.

Background/Aims: Patients with active cancer frequently develop venous thromboembolism (VTE). However, there is little data about VTE in patients with advanced cholangiocarcinoma (CCA). Therefore, we investigated the clinical significance of VTE in patients with advanced CCA. Methods: We analyzed the data of a total of 332 unresectable CCA patients diagnosed between 2010 and 2020 in this retrospective study. We investigated the incidence and risk factors for VTE, and its effect on survival in patients with advanced CCA. Results: During a median follow-up of 11.6 months, 118 patients (35.5%) developed VTE. The cumulative incidence of VTE was 22.4% (95% confidence interval [CI], 0.18 to 0.27) at 3 months and 32.8% (95% CI, 0.27 to 0.38) at 12 months. Major vessel invasion was an independent risk factor for VTE (hazard ratio, 2.88; 95% CI, 1.92 to 4.31; p<0.001). Patients who developed VTE during follow-up had shorter overall survival than patients who did not (11.50 months vs 15.83 months, p=0.005). In multivariable analysis, VTE (hazard ratio, 1.58; 95% CI, 1.23 to 2.02; p<0.001) was associated with poor overall survival. Conclusions: Major vessel invasion is related to the occurrence of VTE in advanced CCA. The development of VTE significantly decreases the overall survival and is an important unfavorable prognostic factor for survival.

A truncated manganese spinel cathode for excellent power and lifetime in lithium-ion batteries.

Spinel-structured lithium manganese oxide (LiMn(2)O(4)) cathodes have been successfully commercialized for various lithium battery applications and are among the strongest candidates for emerging large-scale applications. Despite its various advantages including high power capability, however, LiMn(2)O(4) chronically suffers from limited cycle life, originating from well-known Mn dissolution. An ironical feature with the Mn dissolution is that the surface orientations supporting Li diffusion and thus the power performance are especially vulnerable to the Mn dissolution, making both high power and long lifetime very difficult to achieve simultaneously. In this investigation, we address this contradictory issue of LiMn(2)O(4) by developing a truncated octahedral structure in which most surfaces are aligned to the crystalline orientations with minimal Mn dissolution, while a small portion of the structure is truncated along the orientations to support Li diffusion and thus facilitate high discharge rate capabilities. When compared to control structures with much smaller dimensions, the truncated octahedral structure as large as 500 nm exhibits better performance in both discharge rate performance and cycle life, thus resolving the previously conflicting aspects of LiMn(2)O(4).

A prospective randomized noninferiority trial comparing conventional smears and SurePathTM liquid-based cytology in endoscopic ultrasound-guided sampling of esophageal, gastric, and duodenal lesions.

BACKGROUND: Several liquid-based cytology (LBC) methods are currently used, but the diagnostic accuracy of each method is not well known. We aimed to compare the diagnostic performance of SurePathTM LBC and conventional smear (CS) cytology in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) samples of esophageal, gastric, and duodenal lesions. METHODS: As a prospective randomized noninferiority study, patients who needed EUS-FNA due to subepithelial mass in the upper gastrointestinal tract were randomly assigned 1:1 to the LBC and CS groups. Cytologic preparation was carried out using a crossover design where 1 method was used for the first needle-pass sample and another method was used for the second needle-pass sample. The primary outcome was to compare the diagnostic performance between LBC and CS using the final diagnosis as the gold standard. RESULTS: A total of 87 patients were randomized and 60 patients were analyzed. There were no differences between LBC and CS in diagnostic accuracy (91.7% vs 86.7%, P = .380), sensitivity (97.7% vs 90.7%, P = .169), specificity (76.5% vs 76.5%, P > .99), negative predictive value (92.9% vs 76.5%, P = .225), or positive predictive value (91.3% vs 90.7%, P = .921). The background of LBC was less bloody than that of CSs (5.0% vs 53.3%, P < .001) and the sample preparation time of LBC was shorter than that of CSs (29 ±â€…7 seconds vs 90 ±â€…17 seconds, P < .001). CONCLUSION: In the EUS-FNA of a subepithelial mass in the upper gastrointestinal tract, the diagnostic performance of LBC was not inferior to that of CS. The field of view was better in LBC, because the background was less bloody and necrotic. As LBC is more convenient to perform and takes shorter time, it is expected that it can replace the CS method for EUS-FNA samples.

Combinatorial Effect of Prophylactic Interventions for Post-ERCP Pancreatitis among Patients with Risk Factors: A Network Meta-Analysis.

Background/Aims: The combinatorial effects of prophylactic methods for postendoscopic retrograde cholangiopancreatography pancreatitis (PEP) in patients with risk factors remain unclear. In this network meta-analysis, we compared the efficacy of various prophylactic strategies to decrease the risk of PEP among patients with risk factors. Methods: A systematic review was performed to identify randomized controlled trials from PubMed, Embase, and the Cochrane Library through July 2021. We used frequentist network meta-analysis to compare the rates of PEP among patients who received prophylactic treatments as follows: class A, rectal nonsteroidal anti-inflammatory drugs; class B, prophylactic pancreatic stent; class C, aggressive hydration; or control, no prophylaxis or active control. We selected those studies that included patients with risk factors for PEP. Results: We identified 19 trials, comprising 4,328 participants. Class ABC (odds ratio [OR], 0.08; 95% confidence interval [CI], 0.03 to 0.24), class AC (OR, 0.10; 95% CI, 0.02 to 0.47), class AB (OR, 0.12; 95% CI, 0.05 to 0.26), class BC (OR, 0.13; 95% CI, 0.04 to 0.41), class A (OR, 0.16; 95% CI, 0.05 to 0.50), and class B (OR, 0.26; 95% CI, 0.14 to 0.46), were associated with a reduced risk of PEP as compared to that of the control. The most effective prophylaxis was ABC (0.87), followed by AC (0.68), AB (0.65), BC (0.56), A (0.49), and B (0.24) according to P-score. Conclusions: The results of this network meta-analysis suggest that the more prophylactic methods are employed, the better the outcomes. It appears that for patients with risk factors, we need to prevent PEP through the use of these well proven combination strategies.

Efficacy and safety of novel hemostatic gel in endoscopic sphincterotomy or endoscopic papillectomy: A multicenter, randomized controlled clinical trial.

BACKGROUND: Endoscopists often experience obstacles with traditional hemostasis using the side-viewing duodenoscope for bleeding after endoscopic sphincterotomy (EST) or endoscopic papillectomy (EP). AIMS: In this randomized controlled trial, we evaluated the efficacy and safety of a novel hemostatic gel for post-EST or post-EP bleeding. METHODS: A randomized trial was conducted from November 2020 to December 2021 at two tertiary centers in South Korea. Patients who experienced bleeding immediately after EST or EP were enrolled in the study, and primary hemostasis was achieved with either the novel hemostatic gel or epinephrine spray. RESULTS: A total of 84 patients were enrolled in this study, and 41 patients were finally analyzed in each group. Hemostatic gel was significantly superior to epinephrine spray for successful primary hemostasis (100% vs. 85.4%; P = 0.026). ). In terms of delayed bleeding, no significant difference was observed between the hemostatic gel and epinephrine spray (2.4% vs. 7.3%; P = 0.329). The mean procedural time was significantly higher for the hemostatic gel than epinephrine spray (3.23 ± 1.94 vs. 1.76 ± 0.99 min; P < 0.001), and no differences were observed in the adverse events. CONCLUSIONS: The novel hemostatic gel is expected to achieve satisfactory results with easier hemostasis for immediate bleeding after EST or EP. (Registered in Clinical Research Information Service: KCT0005607).

Analysis of ultrasonographic images using a deep learning-based model as ancillary diagnostic tool for diagnosing gallbladder polyps.

BACKGROUND: Accurately diagnosing gallbladder polyps (GBPs) is important to avoid misdiagnosis and overtreatment. AIMS: To evaluate the efficacy of a deep learning model and the accuracy of a computer-aided diagnosis by physicians for diagnosing GBPs. METHODS: This retrospective cohort study was conducted from January 2006 to September 2021, and 3,754 images from 263 patients were analyzed. The outcome of this study was the efficacy of the developed deep learning model in discriminating neoplastic GBPs (NGBPs) from non-NGBPs and to evaluate the accuracy of a computer-aided diagnosis with that made by physicians. RESULTS: The efficacy of discriminating NGBPs from non- NGBPs using deep learning was 0.944 (accuracy, 0.858; sensitivity, 0.856; specificity, 0.861). The accuracy of an unassisted diagnosis of GBP was 0.634, and that of a computer-aided diagnosis was 0.785 (p<0.001). There were no significant differences in the accuracy of a computer-aided diagnosis between experienced (0.835) and inexperienced (0.772) physicians (p = 0.251). A computer-aided diagnosis significantly assisted inexperienced physicians (0.772 vs. 0.614; p < 0.001) but not experienced physicians. CONCLUSIONS: Deep learning-based models discriminate NGBPs from non- NGBPs with excellent accuracy. As ancillary diagnostic tools, they may assist inexperienced physicians in improving their diagnostic accuracy.

Development of novel biliary metal stent with coil-spring structure and its application in vivo swine biliary stricture model.

Background: As of date, endoscopic biliary stenting with plastic stent (PS) and self-expandable metal stent (SEMS) have been widely used for the palliation of biliary tract strictures. However, these two stents have several limitations regarding the management of biliary strictures caused by intrahepatic and hilar cholangiocarcinoma. PS has short patency and also risks bile duct injury and bowel perforation. SEMS is difficult to revise when occluded by tumor overgrowth. To compensate for such shortcomings, we developed a novel biliary metal stent with coil-spring structure. The aim of this study was to investigate the feasibility and efficacy of the novel stent in a swine model. Methods: The biliary stricture model was prepared in six mini-pigs using endobiliary radiofrequency ablation. Conventional PS (n=2) and novel stents (n=4) were deployed endoscopically. Technical success was defined as successful stent placement and clinical success was defined as >50% reduction of serum bilirubin level. Adverse events, stent migration, and endoscopic removability for one month after stenting were also assessed. Results: The biliary stricture was successfully created in all animals. The technical success rate was 100 %, and the clinical success rate was 50% in the PS group and 75% in the novel stent group. In the novel stent group, the median pre- and post-treatment serum bilirubin levels were 3.94 and 0.3 mg/dL. Stent migration occurred in two pigs and two stents were removed by endoscopy. There was no stent-related mortality. Conclusions: The newly designed biliary metal stent was feasible and effective in a swine biliary stricture model. Further studies are needed to verify the usefulness of the novel stent in the management of biliary strictures.