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.

Biphasic Regulation of Apoptosis Following Gastric Irreversible Electroporation Using Tissue Immunohistochemistry of Activated Caspase-3 with TUNEL Method.

The regulation of apoptosis is the primary goal of ablation therapy. Irreversible electroporation (IRE) is a promising non-thermal tissue ablation-based therapy that induces apoptosis by manipulating electrical conditions. This study aimed to investigate IRE-induced gastric tissue apoptosis in response to changes in the electric field intensity, followed by the repair process. Among the 52 rats used in this study, 24 were used to explore apoptosis, and 28 were used to study regeneration. The apoptosis-to-necrosis ratio of the electrical field strength was evaluated using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and caspase-3 immunohistochemistry. The size of IRE-induced ulcers in the gastric tissue continuously increased with increasing electrical intensity (r2 = 0.830, p < 0.001). The level of apoptosis gradually decreased after peaking at 200 V (1000 V/cm). The size of the 400 V-ablated ulcers continued to decrease, and they were not visible by day 14. The proliferation and migration of epithelial cells with fibroblasts were observed on day 3 and augmented on day 7 post-ablation. This investigation demonstrated the biphasic activation of apoptosis with respect to the electrical field strength. Visually and histologically, IRE-induced gastric ulcers demonstrated complete tissue regeneration after two weeks.

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.

Factors associated with gastric and duodenal neuroendocrine tumors: A multicenter case-control study.

BACKGROUND AND AIMS: The incidence of gastric and duodenal neuroendocrine tumors (GNET and DNET, respectively) is increasing, however associated factors of these diseases are not well known. Here, we investigated the factors associated with GNET and DNET. METHODS: Patients with GNET and DNET presenting at eight tertiary referral centers between 2001 and 2020 were included and compared with healthy controls who underwent upper endoscopic screening. Clinical factors and laboratory data were analyzed to determine associated factors of GNET and DNET. RESULTS: Overall, 396 patients with GNET and 193 patients with DNET were included and compared with 1725 healthy controls. Multivariate analysis showed that age (odds ratio [OR] 0.98), diabetes (OR 1.72), hypertension (OR 1.97), low serum high-density lipoprotein cholesterol (HDL-C) levels (OR 2.54), and past/present H. pylori infection (OR 1.46) were significantly associated with GNET. In contrast, DNET was significantly associated with diabetes (OR 1.80), hypertension (OR 1.68), low serum HDL-C levels (OR 2.29), and past/present H. pylori infection (OR 5.42). In the sex-based subgroup analysis in GNET, current smoking was strongly associated in women (OR 9.85), but not in men. CONCLUSIONS: This study identified several common metabolic factors associated with GNET and DNET. Additionally, some factors had sex-specific associations.

The Effect of Tegoprazan on the Treatment of Endoscopic Resection-Induced Artificial Ulcers: A Multicenter, Randomized, Active-Controlled Study.

Background/Aims: : Tegoprazan is a novel potassium-competitive acid blocker that has beneficial effects on acid-related disorders such as gastroesophageal reflux and peptic ulcer diseases. This study aimed to validate the effect of tegoprazan on endoscopic submucosal dissection (ESD)-induced artificial ulcers. Methods: : Patients from 16 centers in Korea who underwent ESD for gastric neoplasia were enrolled. After ESD, pantoprazole was administered intravenously for 48 hours. The patients were randomly allocated to either the tegoprazan or esomeprazole group. Tegoprazan 50 mg or esomeprazole 40 mg were administered for 4 weeks, after which gastroscopic evaluation was performed. If the artificial ulcer had not healed, the same dose of tegoprazan or esomeprazole was administered for an additional 4 weeks, and a gastroscopic evaluation was performed. Results: : One hundred sixty patients were enrolled in this study. The healing rates of artificial ulcers at 4 weeks were 30.3% (23/76) and 22.1% (15/68) in the tegoprazan and esomeprazole groups, respectively (p=0.006). At 8 weeks after ESD, the cumulative ulcer healing rates were 73.7% (56/76) and 77.9% (53/68) in the tegoprazan and esomeprazole groups, respectively (p=0.210). Delayed bleeding occurred in two patients in the tegoprazan group (2.6%) and in one patient in the esomeprazole group (1.5%). Other adverse events were negligible in both groups. Conclusions: : Tegoprazan showed similar effects on post-ESD artificial ulcer healing in comparison with esomeprazole.

Reappraisal of optimal reconstruction after distal gastrectomy - a study based on the KLASS-07 database.

BACKGROUNDS: This study aimed to compare the incidence of bile reflux, quality of life (QoL), and nutritional status among Billroth II (BII), Billroth II with Braun anastomosis (BII-B), and Roux-en-Y (RY) reconstruction after laparoscopic distal gastrectomy (LDG). MATERIALS AND METHODS: We reviewed the prospective data of 397 patients from a multicentre database who underwent LDG for gastric cancer between 2018 and 2020 at 20 tertiary teaching hospitals in Korea. Postoperative endoscopic findings, QoL surveys using the European Organization for Research and Treatment of Cancer questionnaire (C30 and STO22), and nutritional and surgical outcomes were compared among groups. RESULTS: In endoscopic findings, bile reflux was the lowest in the RY group ( n =67), followed by the BII-B ( n =183) and BII groups ( n =147) at 1 year (3.0 vs. 67.8 vs. 84.4%, all P <0.05). The anti-reflux capability of BII-B was statistically better than that of BII, but not as perfect as that of RY. From the perspective of QoL, BII-B was not inferior to RY, but better than BII reconstruction in causing fewer STO22 reflux symptoms at 6 and 12 months. However, only RY caused fewer C30 nausea symptoms than BII at 6 and 12 months, but not BII-B. Nutritional status and morbidities were similar among the three groups, and the operative time did not differ between the BII-B and RY groups. CONCLUSIONS: BII-B cannot substitute for RY in preventing bile reflux, shortening the operative time, or reducing morbidities. Regarding short-term QoL, BII-B was sufficient to reduce STO22 reflux symptoms but failed to reduce C30 nausea symptoms postoperatively.

Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy.

With an aging population, the number of patients with difficulty swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. Long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach, aided endoscopically, which may be an alternative to a nasogastric tube when enteral nutritional is required for 4 weeks or more. This paper is the first Korean clinical guideline for PEG. It was developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

[Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy].

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

Clinical practice guidelines for percutaneous endoscopic gastrostomy.

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tube removal for PEG based on the currently available clinical evidence.

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.

Exploring objective factors to predict successful outcomes after laparoscopic Nissen fundoplication.

BACKGROUND: Currently, the reported parameters that predict the resolution of symptoms after surgery are largely subjective and unreliable. Considering that fundoplication rebuilds the structural integrity of the lower esophageal sphincter (LES), the authors focused on searching for objective and quantitative predictors for the resolution of symptoms based on the anatomical issues and whether an antireflux barrier can be well established or not. MATERIALS AND METHODS: The authors reviewed the prospectively collected data of 266 patients with gastroesophageal reflux disease (GERD) who had undergone laparoscopic Nissen fundoplication (LNF). All patients were diagnosed with GERD using preoperative esophagogastroduodenoscopy, 24-h ambulatory esophageal pH monitoring, and high-resolution esophageal manometry. The patients received GERD symptom surveys using the validated Korean Antireflux Surgery Group questionnaire twice: preoperatively and 3 months after the surgery. RESULTS: After excluding patients with insufficient follow-up data, 152 patients were included in the analysis. Multivariate logistic regression analyses revealed that a longer length of the LES and lower BMI determined better resolution of typical symptoms after LNF (all P <0.05). Regarding atypical symptoms, higher resting pressure of LES and DeMeester score greater than or equal to 14.7 were associated with better resolution after the surgery (all P <0.05). After LNF, typical symptoms improved in 34 out of 37 patients (91.9%) with a length of LES >greater than .05 cm, BMI less than 23.67 kg/m 2 , and atypical symptoms were resolved in 16 out of 19 patients (84.2%) with resting pressure of LES greater than or equal to 19.65 mm Hg, DeMeester score greater than or equal to 14.7. CONCLUSION: These results show that the preoperative length and resting pressure of LES is important in the objective prediction of symptom improvement after LNF.

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.

Efficacy and safety of intragastric balloon for obesity in Korea.

BACKGROUND/AIMS: Intragastric balloon (IGB) is the only available endoscopic bariatric and metabolic therapy in Korea. End-ball (Endalis) has the longest history of clinical use among the IGBs available in Korea. However, little clinical data on this system have been reported. In this study, we aimed to evaluate the efficacy and safety of End-ball in Korea. METHODS: We performed a retrospective cohort study of patients who underwent IGB insertion (End-ball) from 2013 to 2019. Demographic and anthropometric data were collected. The efficacy and safety of IGB treatment were analyzed. RESULTS: In total, 80 patients were included. Mean age was 33.7 years and 83.8% were female. Initial body mass index was 34.48±4.69 kg/m2. Body mass index reduction was 3.72±2.63 kg/m2 at the time of IGB removal. Percent of total body weight loss (%TBWL) was 10.76%±6.76%. Percentage excess body weight loss was 43.67%±27.59%. Most adverse events were minor, and 71.4% of participants showed nausea, vomiting, or abdominal pain. CONCLUSION: IGB treatment showed good efficacy and safety profile in Korean patients with obesity. In terms of %TBWL and percentage excess body weight loss, the efficacy was similar to that in the Western population.

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.

Intra-instrument channel workable, optical-resolution photoacoustic and ultrasonic mini-probe system for gastrointestinal endoscopy.

There has been a long-standing expectation that the optical-resolution embodiment of photoacoustic tomography could have a substantial impact on gastrointestinal endoscopy by enabling microscopic visualization of the vasculature based on the endogenous contrast mechanism. Although multiple studies have demonstrated the in vivo imaging capability of a developed imaging device over the last decade, the implementation of such an endoscopic system that can be applied immediately when necessary via the instrument channel of a video endoscope has been a challenge. In this study, we developed a 3.38-mm diameter catheter-based, integrated optical-resolution photoacoustic and ultrasonic mini-probe system and successfully demonstrated its intra-instrument channel workability for the standard 3.7-mm diameter instrument channel of a clinical video endoscope based on a swine model. Through the instrument channel, we acquired the first in vivo dual-mode photoacoustic and ultrasonic endoscopic images from the esophagogastric junction of a swine. Further, in a rat colorectum in vivo imaging experiment, we visualized hierarchically developed mesh-like capillary networks with a hole size as small as ~50 µm, which suggests the potential level of image details that could be photoacoustically provided in clinical settings in the future.

Delayed Bronchial Obstruction following Esophageal Stent Implantation: A Case Report.

Airway compression is a rare complication of esophageal stent placement. With the introduction of self-expanding metal stents, the incidence of bronchial obstruction by esophageal stents has decreased. Delayed external airway compression after esophageal stent implantation is rarely reported. We describe a case of left main bronchial obstruction after self-expandable esophageal stent placement. A 70-year-old patient with advanced esophageal cancer visited the emergency room (ER) with worsening cough and dyspnea. He had received palliative concurrent chemoradiotherapy after esophageal self-expanding metal stent (SEMS) insertion three months ago. One month before the ER visit, additional esophageal SEMS placement (stent-in-stent) was performed owing to the development of a tracheoesophageal fistula. After hospitalization, chest radiography revealed a patchy consolidation in the left lower lobe. A diagnosis of pneumonia was made, and the patient was treated with antibiotics. Seven days after antibiotic treatment, the patient developed a fever and severe dyspnea. Auscultation revealed the absence of breath sounds in the left hemithorax. A follow-up chest radiograph showed a white-out of the left hemithorax. Flexible bronchoscopy revealed luminal narrowing of the left main bronchus (LMB) due to external compression. Chest computed tomography further demonstrated compression of the LMB by esophageal stents. This case highlights that esophageal SEMS can present as an emergent and often life-threatening airway obstruction.

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.

Development of artificial intelligence system for quality control of photo documentation in esophagogastroduodenoscopy.

BACKGROUND: Esophagogastroduodenoscopy (EGD) is generally a safe procedure, but adverse events often occur. This highlights the necessity of the quality control of EGD. Complete visualization and photo documentation of upper gastrointestinal (UGI) tracts are important measures in quality control of EGD. To evaluate these measures in large scale, we developed an AI-driven quality control system for EGD through convolutional neural networks (CNNs) using archived endoscopic images. METHODS: We retrospectively collected and labeled images from 250 EGD procedures, a total of 2599 images from eight locations of the UGI tract, using the European Society of Gastrointestinal Endoscopy (ESGE) photo documentation methods. The label confirmed by five experts was considered the gold standard. We developed a CNN model for multi-class classification of EGD images to one of the eight locations and binary classification of each EGD procedure based on its completeness. RESULTS: Our CNN model successfully classified the EGD images into one of the eight regions of UGI tracts with 97.58% accuracy, 97.42% sensitivity, 99.66% specificity, 97.50% positive predictive value (PPV), and 99.66% negative predictive value (NPV). Our model classified the completeness of EGD with 89.20% accuracy, 89.20% sensitivity, 100.00% specificity, 100.00% PPV, and 64.94% NPV. We analyzed the credibility of our model using a probability heatmap. CONCLUSIONS: We constructed a CNN model that could be used in the quality control of photo documentation in EGD. Our model needs further validation with a large dataset, and we expect our model to help both endoscopists and patients by improving the quality of EGD procedures.