A Novel Retractable Robotic Device for Colorectal Endoscopic Submucosal Dissection.

Background/Aims: : Appropriate tissue tension and clear visibility of the dissection area using traction are essential for effective and safe endoscopic submucosal dissection (ESD). In this study, we developed a retractable robot-assisted traction device and evaluated its performance in colorectal ESD. Methods: : An experienced endoscopist performed ESD 18 times on an ex vivo porcine colon using the robot and 18 times using the conventional method. The outcome measures were procedure time, dissection speed, procedure-related adverse events, and blind dissection rate. Results: : Thirty-six colonic lesions were resected from ex vivo porcine colon samples. The total procedure time was significantly shorter in robot-assisted ESD (RESD) than in conventional ESD (CESD) (20.1±4.1 minutes vs 34.3±8.3 minutes, p<0.05). The submucosal dissection speed was significantly faster in the RESD group than in the CESD group (36.8±9.2 mm2/min vs 18.1±4.7 mm2/min, p<0.05). The blind dissection rate was also significantly lower in the RESD group (12.8%±3.4% vs 35.1%±3.9%, p<0.05). In an in vivo porcine feasibility study, the robotic device was attached to a colonoscope and successfully inserted into the proximal colon without damaging the colonic wall, and ESD was successfully performed. Conclusions: : The dissection speed and safety profile improved significantly with the retractable RESD. Thus, our robotic device has the potential to provide simple, effective, and safe multidirectional traction during colonic ESD.

Application of natural orifice transluminal endoscopic surgery with ENDOCRAB system for stomach perforation model: ex vivo porcine study.

Iatrogenic stomach perforation is a detrimental, irreversible, and fatal condition. Traditional surgery and endoscopic suturing clips and devices have been introduced to seal holes and prevent sepsis and disease progression. However, the development of endoscopic devices for perforations remains challenging, with no standard device available. This study investigates the superficial layer approximation strengths of the newly designed ENDOCRAB system for gastric wall defects. Thirty porcine stomachs were prepared ex vivo for the perforation model and distributed equally into three groups: ENDOCRAB system, Through-the-Scope Clip (TTSC), and hand suturing (HS). Both ENDOCRAB and TTSC achieved mucosal-submucosal layer apposition, whereas HS allowed a full-thickness layer. Their air leakage pressure and procedural duration were measured. The analysis of air-leakage pressure demonstrated comparable suture strength between ENDOCRAB (118.5 ± 41.7 mmHg) and HS (127.4 ± 30.2 mmHg, P = 0.812), but inferior strength with TTSC (73.6 ± 21.6 mmHg, P = 0.012). HS achieved the shortest procedural duration, whereas ENDOCRAB and TTSC showed no significant differences. The ENDOCRAB system showed significantly greater strength than the TTSC, was comparable to HS in strength, and required a procedural duration similar to that of the TTSC. Furthermore, long-term in vivo experiments and histological evaluations are essential.

Robot-assisted gastric endoscopic submucosal dissection significantly improves procedure time at challenging dissection locations.

BACKGROUND: Endoscopic submucosal dissection (ESD) is the standard treatment for early malignant stomach lesions. However, this procedure is technically demanding and carries a high complication risk. The level of difficulty in performing ESD is influenced by the location of the lesion. In our study, we aimed to investigate and analyze the effectiveness of robot-assisted ESD for lesions situated in challenging locations within the stomach. METHODS: We developed a gastric simulator that could be used to implement various gastric ESD locations. An EndoGel (Sunarrow, Tokyo, Japan) was attached to the simulator for the dissection procedures. Robot-assisted or conventional ESD was performed at challenging or easy locations by two ESD-trainee endoscopists. RESULTS: The procedure time was remarkably shorter for robotic ESD than conventional dissection at challenging locations (6.2 vs. 10.2 min, P < 0.05), mainly due to faster dissection (220.3 vs. 101.9 mm2/min, P < 0.05). The blind dissection rate was significantly lower with robotic ESD than with the conventional method (17.6 vs. 35.2%, P < 0.05) at challenging locations. CONCLUSION: The procedure time was significantly shortened when robot-assisted gastric ESD procedures were performed at challenging locations. Therefore, our robotic device provides simple, effective, and safe multidirectional traction for endoscopic submucosal dissection at challenging locations, thereby reducing difficulty of the procedure.

Assessment of efficacy and safety of advanced endoscopic irreversible electroporation catheter in the esophagus.

Nonthermal irreversible electroporation (NTIRE) is emerging as a promising tissue ablation technique. However, maintaining irreversible electroporation (IRE) electrodes against displacement during strong esophageal spasms remains an obstacle. The present study aimed to evaluate the efficacy and safety of newly designed balloon-type endoscopic IRE catheters. Six pigs were randomly allocated to each catheter group, and each pig was subjected to four ablations at alternating voltages of 1500 V and 2000 V. Esophagogastroscopy was performed during the IRE. The ability of balloon-type catheters to execute complete IRE with 40 pulses was assessed. The success rate was higher for the balloon-type catheter than that for the basket-type (12/12 [100%] vs. 2/12 [16.7%], p < 0.001). Following gross inspection and histologic analysis of the 1500-V vs. 2000-V balloon-type catheter revealed a larger mucosal damage area (105.3 mm2 vs. 140.8 mm2, p = 0.004) and greater damage depth (476 µm vs. 900 µm, p = 0.02). Histopathology of the ablated tissue revealed separated epithelium, inflamed lamina propria, congested muscularis mucosa, necrotized submucosa, and disorganized muscularis propria. Balloon-type catheters demonstrated efficacy, achieving full electrical pulse sequences under NTIRE conditions, and a safe histological profile below 2000 V (1274 V/cm). Optimal electrical conditions and electrode arrays pose ongoing challenges.

Propensity score-matched analysis of physician-controlled wire-guided cannulation as an effective technique against difficult cannulation in endoscopic retrograde cholangiopancreatography: A retrospective study.

BACKGROUND: Advanced endoscopic retrograde cholangiopancreatography (ERCP) cannulation strategies for difficult cases could replace conventional techniques, in which assistants control guidewires. We aimed to compare the safety and efficacy of a new salvage cannulation strategy, physician-controlled wire-guided cannulation (PCWGC), with those of a conventional strategy. METHODS: This retrospective study included patients with naïve papillae who underwent ERCP between January 2018 and December 2020. Patients, divided into two groups, received initial cannulation using a conventional catheter. After failed cannulation, the second attempt used PCWGC and double-guidewire technique (DGT) in the new and conventional strategy groups, respectively. Propensity score-matching (PSM) analysis compared outcomes between groups. Primary outcome included overall success rate, while secondary outcomes included cannulation time, adverse events, and cannulation difficulty subgroup analysis. RESULTS: The new strategy group comprised 255 (47.6%) of 536 patients who underwent ERCP. The total cannulation success rate was 98.4% (vs. 97.2%, p = 0.318), with similar post-ERCP pancreatitis (PEP) (1.8% vs. 2.4%, p = 0.64) rates. Following 1:1 PSM, 219/438 patients were allocated to both the conventional and new strategy groups, and 46 patients from the difficult cannulation subgroup were distributed evenly among groups. No difference in overall cannulation success rate existed between the groups before (97.2% vs. 98.4%) and after PSM (96.8% vs. 98.2%). The primary cannulation success rate was higher in the conventional strategy group, while the secondary cannulation success rate was higher in the new strategy group. However, the difficult cannulation subgroup PSM results showed that only the salvage cannulation success rate was significant (9/23, 39.1% vs. 18/23, 78.3%, p = 0.007). In the difficult cannulation subgroup, the salvage cannulation success rate for PCWGC was four times higher than DGT (95% confidence interval; 1.129-14.175), with no significant difference in PEP rate (p = 0.571). CONCLUSIONS: PCWGC demonstrated greater efficacy than the conventional salvage technique. PCWGC could be a safe and useful technique, especially for difficult biliary cannulation.

Bowel Preparation Efficacy and Safety of 1 L vs 2 L Polyethylene Glycol With Ascorbic Acid for Colonoscopy: A Randomized Controlled Trial.

INTRODUCTION: Polyethylene glycol with ascorbic acid (PEG/Asc) is a well-established bowel preparation solution with guaranteed effectiveness and safety. A new low-volume agent, 1 L-PEG/Asc, has recently been released. This study aimed to compare the bowel cleansing efficacy and safety of 1 L-PEG/Asc and 2 L-PEG/Asc administered to adult outpatients in a split-dose manner. METHODS: Outpatients undergoing colonoscopy enrolled in a single-blinded, single-center, noninferiority study conducted between July and October 2021 were randomized in a 1:1 manner to a 1 L-PEG/Asc or 2 L-PEG/Asc group. Bowel cleansing was assessed using the Boston Bowel Preparation Scale (BBPS) and the Harefield Cleansing Scale in intention-to-treat and per-protocol populations. RESULTS: Two hundred forty participants were randomized and allocated, with 120 patients in the 1 L and 2 L-PEG/Asc groups, respectively. Noninferiority was demonstrated for overall successful bowel cleansing (BBPS: 92.5% vs 90.8%; 95% confidence interval [CI], -0.054 to 0.087) and the high-quality cleansing rate of the right-sided colon (BBPS = 3, 40.0% vs 35.8%; 95% CI, -0.082 to 0.165; Harefield Cleansing Scale ≥3, 50.0% vs 43.3%; 95% CI, -0.060 to 0.194) in the intention-to-treat population. The overall incidence of adverse events was similar in both groups ([82/120] 68.3% vs [72/120] 60.0%; P = 0.178). The tolerability, acceptability, and compliance rates of both regimens were similar, with no significant differences. DISCUSSION: Compared with 2 L-PEG/Asc, 1 L-PEG/Asc achieved successful overall bowel cleansing efficacy with high-quality cleansing in the proximal colon and proved its noninferiority. Therefore, 1 L-PEG/Asc is an acceptable alternative bowel cleansing solution.

Observation for the feasibility of a bile duct biopsy technique using a loop-tip guidewire during endoscopic retrograde cholangiopancreatography.

Endoscopists frequently have difficulty approaching biliary lesions using biopsy forceps. The aim of this study was not only to describe an easy technique for biliary biopsy assisted by a looped guidewire but also to present preliminary results regarding its safety and feasibility. A preliminary proof-of-concept study was performed at a single tertiary medical center. Between August 2019 and January 2020, 13 patients with bile duct strictures underwent endoscopic retrograde cholangiopancreatography (ERCP) with a new loop guidewire-assisted forceps approach technique. The efficacy and safety were evaluated using the success rate as the primary outcome and diagnostic yield and complication rates as secondary outcomes. The tissue sampling success rate was 100% (13/13). All samples were acceptable for histopathological analysis. Eleven specimens were confirmed to be adenocarcinomas. After reexamination of the remaining 2 patients, all cases were eventually diagnosed as being malignant. The sensitivity of the single procedure was 84.6% (11/13). There were 2 patients with mild hyperamylasemia, but there were no severe complications with respect to safety. This new technique could enhance the success rate and diagnostic yield and reduce the risk of failure when using the biopsy forceps approach during ERCP.

Clinical Features and Long-term Prognosis of Crohn's Disease in Korea: Results from the Prospective CONNECT Study.

Background/Aims: The prospective Crohn's Disease Clinical Network and Cohort Study is a nationwide multicenter cohort study of patients with Crohn's disease (CD) in Korea, aiming to prospectively investigate the clinical features and long-term prognosis associated with CD. Methods: Patients diagnosed with CD between January 2009 and September 2019 were prospectively enrolled. They were divided into two cohorts according to the year of diagnosis: cohort 1 (diagnosed between 2009 and 2011) versus cohort 2 (between 2012 and 2019). Results: A total of 1,175 patients were included, and the median follow-up duration was 68 months (interquartile range, 39.0 to 91.0 months). The treatment-free durations for thiopurines (p<0.001) and anti-tumor necrosis factor agents (p=0.018) of cohort 2 were shorter than those of cohort 1. Among 887 patients with B1 behavior at diagnosis, 149 patients (16.8%) progressed to either B2 or B3 behavior during follow-up. Early use of thiopurine was associated with a reduced risk of behavioral progression (adjusted hazard ratio [aHR], 0.69; 95% confidence interval [CI], 0.50 to 0.90), and family history of inflammatory bowel disease was associated with an increased risk of behavioral progression (aHR, 2.29; 95% CI, 1.16 to 4.50). One hundred forty-one patients (12.0%) underwent intestinal resection, and the intestinal resection-free survival time was significantly longer in cohort 2 than in cohort 1 (p=0.003). The early use of thiopurines (aHR, 0.35; 95% CI, 0.23 to 0.51) was independently associated with a reduced risk of intestinal resection. Conclusions: The prognosis of CD in Korea appears to have improved over time, as evidenced by the decreasing intestinal resection rate. Early use of thiopurines was associated with an improved prognosis represented by a reduced risk of intestinal resection.

Colonic stenting as a bridge to surgery for obstructive colon cancer: is it safe in the long term?

BACKGROUND: The placement of a self-expanding metal stent in patients with obstructive colon cancer is used as a bridge to surgery. However, due to a lack of consensus and insufficient data, the long-term oncologic outcomes after colonic SEMS placement remain unclear. We assessed the long-term oncologic outcomes and adverse effects of colonic stenting for malignant colonic obstruction. METHODS: We included 198 patients admitted to Korea University Anam Hospital between 2006 and 2014 for obstructive colon cancer, of whom 98 underwent SEMS placement as a bridge to surgery and 100 underwent direct surgery without stenting. The clinicopathologic characteristics, overall survival, and disease-free survival were compared. RESULTS: There were no significant differences in long-term oncologic outcomes between the two groups. The median follow-up durations were 61.55 and 58.64 months in the SEMS and DS groups, respectively. There were also no significant differences in the 5-year OS (77.4% vs. 74.2%, p = 0.691) and 5-year DFS (61.7% vs. 71.0%, p = 0.194) rates between the groups. However, the DS group had significantly more early postoperative complications (p = 0.002). CONCLUSIONS: Colonic SEMS deployment as a bridge to surgery did not negatively affect long-term oncologic outcomes when compared with DS. In addition, colonic stenting decreased early postoperative complications and reduced the time for patients to return to normal daily activities.

Quality of Life in Newly Diagnosed Moderate-to-Severe Ulcerative Colitis: Changes in the MOSAIK Cohort Over 1 Year.

Background/Aims: Improving quality of life has been gaining importance in ulcerative colitis (UC) management. The aim of this study was to investigate changes in health-related quality of life (HRQL) and related factors in patients with moderate-to-severe UC. Methods: A multicenter, hospital-based, prospective study was performed using a Moderate-to-Severe Ulcerative Colitis Cohort in Korea (the MOSAIK). Changes in HRQL, evaluated using the 12-Item Short Form Health Survey (SF-12) and Inflammatory Bowel Disease Questionnaire (IBDQ), were analyzed at the time of diagnosis and 1 year later. Results: In a sample of 276 patients, the mean age was 38.4 years, and the majority of patients were male (59.8%). HRQL tended to increase in both the IBDQ and SF-12 1 year after diagnosis. A higher partial Mayo score was significantly related to poorer HRQL on the IBDQ and SF-12 in a linear mixed model (p<0.01). Inflammatory markers such as C-reactive protein (CRP) or erythrocyte sedimentation rate also showed a negative correlation on HRQL (p<0.05). Patients whose IBDQ score improved by 16 or more (71.2%) in 1 year were younger, tended to be nonsmokers, and had a lower partial Mayo score and CRP than those whose IBDQ score did not. There was no significant association between HRQL and disease extent, treatments at diagnosis, or the highest treatment step during the 1-year period. Conclusions: Optimally controlled disease status improves HRQL in patients with moderate-to-severe UC. The partial Mayo score and inflammatory markers may be potential indicators reflecting the influence of UC on patient`s daily lives.

Efficacy and safety of split-dose bowel preparation with 1 L polyethylene glycol and ascorbate compared with 2 L polyethylene glycol and ascorbate in a Korean population: a phase IV, multicenter, randomized, endoscopist-blinded study.

BACKGROUND AND AIMS: The 1-L polyethylene glycol (PEG)-based bowel preparation agent NER1006 (Plenvu; Norgine, Harefield, UK) has shown high cleansing efficacy and tolerability in clinical trials in Europe and North America. However, no clinical trials have yet been reported in Asia. Therefore, the aim of this study was to evaluate the efficacy and safety of 1L PEG-based bowel preparation with Plenvu compared with 2L PEG plus ascorbate bowel preparation in a Korean population. METHODS: In this multicenter, endoscopist-blinded, randomized study, patients at 9 hospitals in South Korea undergoing colonoscopy received either Plenvu or 2L PEG + ascorbate (2L PEG) with a split dose. The primary endpoint was overall bowel cleansing success (Boston Bowel Preparation Scale [BBPS] score ≥2 for all segments of the colon). Secondary endpoints were high-quality bowel cleansing success (overall, BBPS score = 9; segmental colon, BPPS score = 3), polyp detection rate (PDR), and adenoma detection rate (ADR). RESULTS: Of 360 included patients, cleansing efficacy was analyzed in 346 (Plenvu, 174; 2L PEG, 172). The Plenvu group showed noninferior bowel cleansing success rates compared with 2L PEG (93.10% vs 91.86%; difference, 1.24%; 1-sided 97.5% lower confidence limit, -4.31%; Pnoninferiority < .0001; Psuperiority = .661). The Plenvu group had higher high-quality bowel cleansing success rates for overall and right-sided colon segments than the 2L PEG group (49.43% vs 37.79% [P = .029] and 60.92% vs 48.84% [P = .024], respectively). The PDR was greater with Plenvu than with 2L PEG (48.85% vs 37.79%, P = .038). However, ADR did not differ between the 2 groups (24.71% vs 20.35%, P = .331). Although treatment-emergent adverse events (TEAEs) were slightly higher in the Plenvu group than in the 2L PEG group (65.71% vs 52.91%, P = .015), most TEAEs were mild (85.55%) and most patients recovered without any management (99.23%). CONCLUSIONS: Plenvu showed noninferior overall bowel cleansing success rates comparable with 2L PEG but greater high-quality bowel cleansing in overall and right-sided colon, which might help improve the PDR in the Asian population. (Clinical trial registration number: KCT0005894.).

Efficacy and Safety of TJP-008 Compared to 2 L PEG with Ascorbate in Colon Cleansing: A Randomized Phase 3 Trial.

BACKGROUND/AIMS: Polyethylene glycol (PEG)-based bowel preparations are effective cleansing agents for colonoscopy. However, they require relatively large volumes to be used even with agents such as 2 L PEG with ascorbate (2LPEG). This phase 3, randomized, single-blinded, multicenter, parallel-group study compared the efficacy of 1 L PEG with high-dose ascorbate, TJP-008, to 2LPEG. METHODS: Patients undergoing colonoscopy were randomized (1:1:1) to receive TJP-008 as 1-day split dose (TJP-008-1) or 2-day split dose (TJP-008-2) regimen or to receive 2LPEG as a 2-day split dose regimen. Cleansing efficacy was evaluated using the Harefield Cleansing Scale. The primary endpoint was overall bowel cleansing success. Full analysis set (FAS) and per protocol set (PPS) analyses were performed. RESULTS: Of the 314 screened patients, efficacy was assessed in the following patient numbers (FAS/PPS): total (293/285), TJP-008-1 (98/94), TJP-008-2 (97/95), and 2LPEG (98/96). FAS revealed noninferiority between TJP-008 and 2LPEG with regard to overall success (TJP-008-2, 99.0%; TJP-008-1, 95.9%; 2LPEG, 94.9%; p=0.100 and p=0.733, respectively). PPS also showed noninferiority (p=0.721 and p=0.211, respectively). However, the PPS analyses showed a higher bowel cleansing score for TJP-008-2 for high-quality cleansing in the right colon (TJP-008-2 83.2% vs 2LPEG 62.5%; p=0.005). CONCLUSIONS: TJP-008 is a new low-volume cleansing agent with a colon cleansing efficacy comparable to that of standard 2LPEG that exhibits significant safety and tolerability.

Effect of histological examination on the diagnosis of pancreatic mass using endoscopic ultrasound fine-needle aspiration.

BACKGROUND: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a well-established method for the diagnosis of solid pancreatic lesions. However, the diagnostic yield of EUS-FNA for pancreatic lesions varies at around 70-90%. Samples from EUS-FNA consist of cells and tissues that can be analyzed separately, and the results can be combined for a final diagnosis. OBJECTIVES: To investigate the effect of cytological and histological analysis of EUS-FNA samples on the final diagnosis, and identify factors that may affect the accuracy of the cytological, histological, and overall analysis. MATERIAL AND METHODS: A single-center prospective observational study was conducted at a tertiary university hospital from July 2018 to June 2019. Patients who underwent EUS-FNA for pancreatic solid lesions with a 22-gauge EUS-FNA needle were included in our study. Liquid-based cytological analysis of the specimen and histological analysis of the whitish core were performed, and factors that affected the diagnostic accuracy of each analysis were evaluated. RESULTS: In 63 EUS-FNA samples, the overall diagnostic accuracy was 87.3%, which was significantly higher than the cytological accuracy of 73.8% (p = 0.031) and the histological accuracy of 69.8% (p = 0.001). Factors that affected the results differed in each group: 1) cytological analysis: size, location, and approach method; 2) histological analysis: specimen weight; and 3) overall analysis: size, location, and approach method. CONCLUSIONS: Histologic evaluation of core material obtained from EUS-FNA improved diagnostic accuracy, and factors that affected each result were analyzed. Further studies with prospective randomized trials are recommended to support our data.

Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein improves diagnostic accuracy for hepatocellular carcinoma.

BACKGROUND: Diagnostic accuracy of various tumor markers and their combinations for hepatocellular carcinoma (HCC) was not fully investigated. AIM: To evaluate the diagnostic accuracy of alpha-fetoprotein (AFP), the Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3), and protein induced by vitamin K absence or antagonist-II (PIVKA-II) and their combination for HCC diagnosis. METHODS: Patients with newly detected liver mass or elevated serum AFP levels were considered eligible. Serum AFP level, AFP-L3 fraction, and PIVKA-II level were measured at the first visit. RESULTS: In total, 622 patients were included; 355 patients (57.1%) had chronic liver disease, and 208 (33.4%) had liver cirrhosis. HCC was diagnosed in 160 patients (25.7%). The area under the receiver operating characteristics curves (AUROCs) of the serum AFP, AFP-L3 fraction, AFP-L3, and PIVKA-II levels for the diagnosis of HCC were 0.775, 0.792, 0.814, and 0.834, respectively. A novel diagnostic model was developed by classifying patients in a 1:1 ratio into training and validation sets. Using the binary regression analysis of the training cohort, the AFP, AFP-L3 fraction, and PIVKA-II (ALPs) score was calculated as follows: ALPs score = 3.8 × [serum AFP level (ng/mL) × AFP-L3 fraction (%) × 0.01] + 0.2 × PIVKA-II level (mAU/mL). The AUROC of the ALPs score for diagnosis of HCC was 0.878, significantly higher than that of serum AFP level (P < 0.001), AFP-L3 fraction (P < 0.001), PIVKA-II level (P = 0.036), and AFP-L3 level (P = 0.006). The optimal ALPs score cut-off was 5.3 (sensitivity, 85.0%, specificity 80.1%). The validation cohort showed similar results. CONCLUSION: The ALPs score calculated using serum AFP level, AFP-L3 fraction, and PIVKA-II level showed improved accuracy in HCC diagnosis.

Feasibility and effectiveness of endoscopic irreversible electroporation for the upper gastrointestinal tract: an experimental animal study.

Irreversible electroporation (IRE) is a local non-thermal ablative technique currently used to treat solid tumors. Here, we investigated the clinical potency and safety of IRE with an endoscope in the upper gastrointestinal tract. Pigs were electroporated with recently designed endoscopic IRE catheters in the esophagus, stomach, and duodenum. Two successive strategies were introduced to optimize the electrical energy for the digestive tract. First, each organ was electroporated and the energy upscaled to confirm the upper limit energy inducing improper tissue results, including bleeding and perforation. Excluding the unacceptable energy from the first step, consecutive electroporations were performed with stepwise reductions in energy to identify the energy that damaged each layer. Inceptive research into inappropriate electrical intensity contributed to extensive hemorrhage and bowel perforation for each tissue above a certain energy threshold. However, experiments performed below the precluded energy accompanying hematoxylin and eosin staining and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays showed that damaged mucosal area and depth significantly decreased with decreased energy. Relevant histopathology showed infiltration of inflammatory cells with pyknotic nuclei at the electroporated lesion. This investigation demonstrated the possibility of endoscopic IRE in mucosal dysplasia or early malignant tumors of the hollow viscus.

Endoscopic submucosal dissection using a detachable assistant robot: a comparative in vivo feasibility study (with video).

BACKGROUND: Appropriate tissue tension and clear visibility of the dissection area using traction are essential for effective and safe endoscopic submucosal dissection (ESD). We developed a robotic assistive traction device for flexible endoscopy and compared its safety and efficiency in ESD between experienced and novice endoscopists. METHODS: Robotic ESD was performed by experienced and novice endoscopist groups (n = 2, each). The outcomes included time to complete each ESD step, total procedure time, size of the dissected mucosa, rate of en bloc resection, and major adverse events. Furthermore, incision and dissection speeds were compared between groups. RESULTS: Sixteen gastric lesions were resected from nine live pigs. The submucosal incision speed was significantly faster in the expert group than in the novice group (P = 0.002). There was no significant difference in the submucosal dissection speed between the groups (P = 0.365). No complications were reported in either group. CONCLUSIONS: When the robot was assisting in the ESD procedure, the dissection speed improved significantly, especially in the novice surgeons. Our robotic device can provide simple, effective, and safe multidirectional traction during ESD.

Natural killer cell activity is a risk factor for the recurrence risk after curative treatment of hepatocellular carcinoma.

BACKGROUND: Natural killer (NK) cells have been known to contribute to surveillance and control of hepatocellular carcinoma (HCC). However, the association of NK cell activity with stage and recurrence risk of HCC have not been fully evaluated. METHODS: Untreated patients with newly diagnosed HCC were prospectively enrolled. Peripheral blood mononuclear cells were isolated at the time of diagnosis. Patients who had undergone surgery or radiofrequency ablation were classified as the curative treatment group, and their blood samples were collected again at 1 month after treatment. RESULTS: A total of 80 patients with HCC were enrolled. The mean age was 62.5 years. At baseline, interferon (IFN)-γ producing NK cell proportion was significantly lower in patients with Barcelona clinic liver cancer (BCLC) stage B, C, or D than in those with BCLC stage 0 (42.9% vs. 56.8%, P = 0.045). Among all patients, 56 patients had undergone curative treatment, and 42 patients re-visited at 1 month after curative treatment. There was no significant change in total NK cell and IFN-γ producing NK cell proportion from baseline to 1 month after treatment (all P > 0.05). During a median follow-up of 12.4 months, HCC recurred in 14 patients (33.3%). When patients were classified according to the IFN-γ producing NK cell proportion (group 1, ≥ 45%; and group 2, < 45%), HCC recurrence rate did not differ according to the IFN-γ producing NK cell proportion at baseline (log-rank test, P = 0.835). However, patients with < 45% IFN-γ producing NK cell proportion at 1 month after treatment had a significantly higher HCC recurrence rate than patients with that of ≥ 45% (log-rank test, P < 0.001). Multivariate analysis revealed that BCLC stage B (hazard ratio [HR] = 3.412, P = 0.045) and < 45% IFN-γ producing NK cell proportion at 1 month after treatment (HR = 6.934, P = 0.001) independently predicted an increased risk of HCC recurrence. CONCLUSIONS: Decreased NK cell activity is significantly associated with the advanced stage of HCC, and the increased recurrence risk of HCC after curative treatment.

Artificial intelligence-assisted analysis of endoscopic retrograde cholangiopancreatography image for identifying ampulla and difficulty of selective cannulation.

The advancement of artificial intelligence (AI) has facilitated its application in medical fields. However, there has been little research for AI-assisted endoscopy, despite the clinical significance of the efficiency and safety of cannulation in the endoscopic retrograde cholangiopancreatography (ERCP). In this study, we aim to assist endoscopists performing ERCP through automatic detection of the ampulla and the identification of cannulation difficulty. We developed a novel AI-assisted system based on convolutional neural networks that predict the location of the ampulla and the difficulty of cannulation to the ampulla. ERCP data of 531 and 451 patients were utilized in the evaluation of our model for each task. Our model detected the ampulla with mean intersection-over-union 64.1%, precision 76.2%, recall 78.4%, and centroid distance 0.021. In classifying the cannulation difficulty, it achieved the recall of 71.9% for the class of easy cases and that of 61.1% for that of difficult cases. Remarkably, our model accurately detected AOV with varying morphological shape, size, and texture on par with the level of a human expert and showed promising results for recognizing cannulation difficulty. It demonstrated its potential to improve the quality of ERCP by assisting endoscopists.

Feasibility of Wearable Display Glasses for Medical Students in the Endoscopy Room.

BACKGROUND/AIMS: Several attempts have been made to incorporate smart glasses in the medical field. We applied wearable display glasses to show the position of an observer during endoscopy and compared students' responses between the conventional and new methods. METHODS: We surveyed 28 medical students regarding the use of wearable display devices. The students used wearable display glasses to observe an endoscopic procedure and answered the prepared questionnaire. Their collected responses were analyzed for statistical correlations between each variable. RESULTS: The survey of medical students revealed disadvantages including dizziness (dissatisfied and very dissatisfied: 21.5%) and eye fatigue (25% dissatisfied) and advantages including concentration (satisfied and very satisfied: 57.2%) and securing patient rights (71.4%). The students showed more positive than negative reviews regarding the new devices (32.1% vs. 21.5%). CONCLUSION: We investigated the advantages and disadvantages of viewing the endoscope image with new wearable display glasses compared to the conventional method using the survey to record user experience. The results revealed relatively positive responses from the medical students in the survey. If the new device compensates for some shortcomings, its use in the endoscopy room will be feasible.