Peroral endoscopic myotomy for treatment of achalasia: initial results of a korean study

Background/Aims

Achalasia is a rare esophageal motility disorder. Recently, a novel endoscopic technique, peroral endoscopic myotomy (POEM), was introduced as an alternative treatment for achalasia. We report the results and short term outcomes of POEM for patients with achalasia.

Methods

POEM was performed in 13 patients with achalasia. The procedure consisted of creating a submucosal tunnel followed by endoscopic myotomy of circular muscle bundles. The mucosal entry was closed by conventional hemostatic clips. A validated clinical symptom score (Eckardt score) and high resolution manometry were used to evaluate the outcomes.

Results

Both the clinical score of achalasia, as well as the resting lower esophageal sphincter (LES) pressure, were significantly reduced after POEM. Mean posttreatment Eckardt score was 0.4±0.7, compared to 6.4±1.9 prior to the treatment (p=0.001). The mean pretreatment and posttreatment LES pressure was 30.3 and 15.3 mm Hg, respectively (p=0.007). Following POEM, symptomatic relief from dysphagia without reflux symptoms was observed in all patients (13/13). No serious complications related to POEM were encountered.

Conclusions

Based upon our initial experience, the authors believe that POEM is a feasible, safe, and effective treatment and may possibly substitute established treatments of refractory achalasia.

Endoscopic ultrasound elastography for the pancreas in Korea: a preliminary single center study

BACKGROUND/AIMS

Endoscopic ultrasound elastography (EUS-EG) has been widely used for the evaluation of pancreatic cancer in the Western world. To date, there is very little experience with EUS-EG in Korea. We described the results of comparison between normal pancreas and pancreatic cancer in Korea.

METHODS

The present study was performed at a tertiary hospital on 35 subjects comprising 20 with normal pancreas (control group) and 15 with pancreatic cancer (disease group). We compared the EUS-EG performance of the two groups.

RESULTS

The pancreas in the control group showed a mean elasticity value of 0.53% (95% confidence interval [CI], 0.45 to 0.61). The elasticity value was higher than that previously reported from Western country (0.47%; 95% CI, 0.38 to 0.57). In the disease group, the mean elasticity value of pancreatic lesions was 0.02% (95% CI, 0.01 to 0.02). The mean elasticity value of the disease group was significantly lower than that of the control group (p<0.0001).

CONCLUSIONS

EUS-EG could be a highly sensitive diagnostic modality for pancreatic cancer in Korea with little EUS-EG experience. We also provided the reference range of elasticity value of normal pancreas, which might be valuable in the interpretation of pancreatic elasticity data for Korean adults.

The clinical features and treatment modality of esophageal neuroendocrine tumors: a multicenter study in Korea

BACKGROUND

Neuroendocrine tumors (NETs) of the esophagus are extremely rare, and few cases have been reported worldwide. Thus, a comprehensive nationwide study is needed to understand the characteristics of and treatment strategy for esophageal NETs.

METHODS

We collected data on esophageal NET patients from 25 hospitals in Korea from 2002-2012. The incidence, location, clinical symptoms, histopathology, treatment response, and the biochemical, radiologic and endoscopic characteristics of esophageal NETs were surveyed.

RESULTS

Among 2,037 NETs arising in different gastrointestinal sites, esophageal NETs were found in 26 cases (1.3%). The mean patient age was 60.12 ± 9.30 years with a 4:1 male predominance. In endoscopic findings, 76.9% (20/26) of NETs were located in the lower third of the esophagus and the mean size was 2.34 ± 1.63 cm. At diagnosis, more than half the patients (15/26, 57.7%) had regional lymph node metastasis or widespread metastasis. Endoscopic resection was conducted in three cases, and in all three of them, lymph node metastasis was not found and tumor size was below 1.0 cm. All tumors were completely removable through endoscopic procedures and there was no recurrence during the follow-up period. Eighteen other patients received an operation, chemotherapy or both. Among them, nine patients (50.0%) expired because of the progression of their cancer or post-operative complications. In Kaplan-Meier survival analysis, only tumor size (more than 2.0 cm) showed prognostic significance (P = 0.045).

CONCLUSIONS

Despite the general assumption that gastrointestinal NETs are benign and slow-growing tumors, the prognosis of advanced esophageal NETs is not favorable.

Accuracy of a scoring system for the differential diagnosis of common gastric subepithelial tumors based on endoscopic ultrasonography

OBJECTIVE

We aimed to validate a new scoring system for the differential diagnosis of gastric subepithelial tumors (SET) based on endoscopic ultrasonography (EUS) findings, and to determine its diagnostic yield for different gastric SET.

METHODS

Data of patients with gastric SET treated with endoscopic mucosal resection, endoscopic submucosal dissection or surgical resection from April 2001 to October 2012 at the Soonchunhyang University Hospital (Bucheon, Korea) were retrospectively reviewed. Four variables, including location, shape, layer of origin and echogenicity of the tumor on EUS were used to validate the new scoring system.

RESULTS

Among the 226 patients with gastric SET, 69 (30.5%) had gastrointestinal stromal tumors (GIST), 68 (30.1%) had ectopic pancreas and 35 (15.5%) had leiomyoma. Most GIST were located at the fundus and body (79.7%), whereas most leiomyomas were found at the cardia (80.0%). Ectopic pancreas was mostly found at the antrum (88.2%). GIST were mainly irregular and round in shape, while ectopic pancreas and lipoma were oval and leiomyomas were irregularly shaped on EUS. With a score range of 0-1 for leiomyoma, 2-3 for GIST, 4-6 for ectopic pancreas and 7-8 for lipoma, the sensitivity and specificity of the scoring system were 75.8% and 85.4% for GIST, 84.6% and 73.1% for ectopic pancreas, 75.9% and 99.5% for leiomyoma and 91.7% and 96.7% for lipoma, respectively.

CONCLUSIONS

The new scoring system was simple and relatively useful for predicting the histology of gastric SET without acquiring tissues. Prospective studies with large sample sizes are needed in the future.

Dietary prevention of Helicobacter pylori-associated gastric cancer with kimchi

To prove whether dietary intervention can prevent Helicobacter pylori-induced atrophic gastritis and gastric cancer, we developed cancer preventive kimchi (cpKimchi) through special recipe and administered to chronic H. pylori-initiated, high salt diet-promoted, gastric tumorigenesis mice model. H. pylori-infected C57BL/6 mice were administered with cpKimchi mixed in drinking water up to 36 weeks. Gross and pathological gastric lesions were evaluated after 24 and 36 weeks, respectively and explored underlying molecular changes to explain efficacies. Cancer preventive actions of anti-inflammation and anti-mutagenesis were compared between standard recipe kimchi (sKimchi) and special recipe cpKimchi in in vitro H. pylori-infected cell model. The erythematous and nodular changes, mucosal ulcerative and erosive lesions in the stomach were noted at 24^th weeks, but cpKimchi administration significantly ameliorated. After 36^th weeks, scattered nodular masses, some ulcers, and thin nodular gastric mucosa were noted in H. pylori-infected mice, whereas these gross lesions were significantly attenuated in cpKimchi group. On molecular analysis, significant expressions of COX-2 and IL-6, activated NF-κB and STAT3, increased apoptosis, and marked oxidative stresses were noted in H. pylori-infected group relevant to tumorigenesis, but these were all significantly attenuated in cpKimchi group. cpKimchi extracts imparted significant selective induction of apoptosis only in cancer cells, led to inhibition of H. pylori-induced proliferation, while no cytotoxicity through significant HO-1 induction in non-transformed gastric cells. In conclusion, daily dietary intake of cpKimchi can be an effective way either to rejuvenate H. pylori-atrophic gastritis or to prevent tumorigenesis supported with the concerted actions of anti-oxidative, anti-inflammatory, and anti-mutagenic mechanisms.

Cost comparison between surgical treatments and endoscopic submucosal dissection in patients with early gastric cancer in Korea

BACKGROUND/AIMS

This study was conducted to evaluate whether medical costs can be reduced using endoscopic submucosal dissection (ESD) instead of conventional surger-ies in patients with early gastric cancer (EGC).

METHODS

Pa-tients who underwent open gastrectomy (OG), laparoscopy-assisted gastrectomy (LAG), and ESD for EGC were recruited from three medical institutions in 2009. For macro-costing, the medical costs for each patient were derived from the ex-penses incurred during the patient's hospital stay and 1-year follow-up. The overall costs in micro-costing were determined by multiplying the unit cost with the resources used during the patients' hospitalization.

RESULTS

A total of 194 patients were included in this study. The hospital stay for ESD was 5 to 8 days and was significantly shorter than the 12-day hospital stay for OG or the 11- to 17-day stay for LAG. Using macro-costing, the average medical costs for ESD during the hospital stay ranged from 2.1 to 3.4 million Korean Won (KRW) per patient, and the medical costs for conventional surgeries were estimated to be between 5.1 million and 8.2 million KRW. There were no significant differences in the 1-year follow-up costs between ESD and conventional surger-ies.

CONCLUSIONS

ESD patients had lower medical costs than those patients who had conventional surgeries for EGC with conservative indications. (Gut Liver, 2015;9174-180).

Randomized controlled trial of low-volume bowel preparation agents for colonic bowel preparation: 2-L polyethylene glycol with ascorbic acid versus sodium picosulfate with magnesium citrate

PURPOSE

Both 2-L polyethylene glycol with ascorbic acid (2-L PEG/Asc) and sodium picosulfate with magnesium citrate (SP/MC) are low-volume combined agents for colonic preparation. The aim of the current study was to compare the preparation adequacy and patient tolerability of 2-L PEG/Asc and SP/MC.

METHODS

We performed a prospective randomized controlled study in outpatients undergoing daytime colonoscopy at a tertiary academic hospital. We compared preparation adequacy based on the Boston Bowel Preparation Scale (BBPS), polyp and adenoma detection rate (PDR and ADR), compliance, tolerability for ease and palatability, intention to reuse, and patient satisfaction using a questionnaire between 2-L PEG/Asc and three sachets of SP/MC, both given in a split-dose method.

RESULTS

A total of 388 patients were evaluated based on intention to treat (ITT) and 356 patients per protocol (PP). No significant differences in preparation adequacy were observed in ITT and PP analyses, based on the BBPS (p > 0.05). The PDR and ADR were greater than 60 and 40% in both groups, respectively (p > 0.05). Compliance levels were higher in the 2-L PEG/Asc group than in the SP/MC group (p < 0.001). Satisfaction (ITT, p = 0.014; PP, p = 0.032) and palatability (ITT and PP, p < 0.001) levels were higher in the SP/MC group than in the 2-L PEG/Asc group, but values for tolerability for ease and intention to reuse were similar in both groups (ITT and PP, p > 0.05).

CONCLUSIONS

Both 2-L PEG/Asc and SP/MC had adequate bowel cleansing efficacy to satisfy PDR and ADR as quality indicator and had showed similar tolerability.

Jackhammer esophagus treated by a peroral endoscopic myotomy

A 49-year-old woman visited our hospital with dysphagia and chest pain. In another hospital, she was diagnosed as reflux esophagitis. Although she had taken proton pump inhibitor and prokinetics drugs for a long time, she was not relieved of any symptoms. On the basis of high resolution manometry and endoscopic ultrasonography findings, Jackhammer esophagus was diagnosed. In this patient, peroral endoscopic myotomy (POEM) was performed for long myotomy of thickened circular muscle. During the procedure, there were no significant complications and she was discharged uneventfully. Symptoms were completely improved during three months after POEM. Here, we report on a case of Jackhammer esophagus treated by POEM.

Endoscopic submucosal dissection using a thulium laser: preliminary results of a new method for treatment of gastric epithelial neoplasia

BACKGROUND AND STUDY AIM

This study aimed to evaluate the feasibility of a novel laser system for endoscopic submucosal dissection (ESD) of gastric epithelial neoplasia.

PATIENTS AND METHODS

A total of 10 patients underwent ESD by a single expert endoscopist. A thulium 2-μm wavelength laser system was used for ESD procedures. Instead of using endoscopy knives, a 550-μm flexible silica fiber was inserted through the working channel of the endoscope.

RESULTS

In all patients, ESD was completed using only the thulium laser, without the need for endoscopy knives. The median total procedure time was 49 minutes (range 35 - 203). In 8 /10 patients (80 %), no active bleeding was observed during ESD. The final pathologic mapping revealed low-grade dysplasia (n = 4), differentiated adenocarcinoma (n = 5), and signet ring cell carcinoma (n = 1). Curative resection was achieved in 9 /10 patients (90 %). There were no significant complications, such as delayed bleeding or perforation.

CONCLUSIONS

The thulium laser system was feasible in ESD of gastric epithelial neoplasia.

High-resolution impedance manometry facilitates assessment of pharyngeal residue and oropharyngeal dysphagic mechanisms

The utility of high-resolution impedance manometry (HRIM) for evaluating oropharyngeal dysphagia (OPD) has been investigated. These approaches are limited because of the sophisticated methodology. A method of transforming HRIM into a simple and useful diagnostic tool for evaluating OPD is needed. A videofluoroscopic swallowing study (VFSS) and HRIM were performed by independent blinded examiners in 26 consecutive healthy volunteers (12 men; median age, 56.5 years) and 10 OPD patients (five men; median age, 59.5 years). Upper esophageal sphincter (UES) relaxation parameters were measured using a standard HRIM protocol. Peristalsis and bolus transit of the pharyngoesophageal (PE) segment were assessed using an HRIM-modified protocol in which the catheter was pulled back 10 cm. PE bolus transits were evaluated with an impedance contour pattern (linear vs. stasis) method. A significant difference was observed between the manometric measures of healthy volunteers and OPD patients for only the duration of pharyngeal contraction (0.49 ± 0.19 vs. 0.76 ± 0.33 s, P = 0.04). The percentage agreement and kappa value for detecting pharyngeal residue between the VFSS and the impedance analysis were 100% and 1.00, respectively. HRIM allowed for comprehensive assessment of abnormal pharyngeal components that caused pharyngeal residue on VFSS in two patients; reduced base of the tongue versus weak pharyngeal contraction in one, and reduced relaxation of the UES versus reduced laryngeal elevation in the remaining patient. Our findings demonstrated that HRIM using a simple methodology (i.e., pull-back of the catheter) detected pharyngeal residue through a simple analysis of the impedance contour pattern (linear vs. stasis). Furthermore, HRIM facilitated a comprehensive assessment of OPD mechanisms and recognition of subtle abnormalities not yet visible to the naked eye on VFSS.

Ever-changing endoscopic treatment for early gastric cancer: Yesterday-today-tomorrow

Endoscopic resection has been an optimal treatment for selected patients with early gastric cancer (EGC) based on advances in endoscopic instruments and techniques. As endoscopic submucosal dissection (ESD) has been widely used for treatment of EGC along with expanding ESD indication, concerns have been asked to achieve curative resection for EGC while guaranteeing precise prediction of lymph node metastasis (LNM). Recently, new techniques including ESD or endoscopic full-thickness resection combined with sentinel node navigation enable minimal tumor resection and a laparoscopic lymphadenectomy in cases of EGC with high risk of LNM. This review covers the development and challenges of endoscopic treatment for EGC. Moreover, a new microscopic imaging and endoscopic techniques for precise endoscopic diagnosis and minimally invasive treatment of EGC are introduced.

Long-term outcomes of balloon dilation versus botulinum toxin injection in patients with primary achalasia

BACKGROUND/AIMS

We compared the long-term outcomes of balloon dilation versus botulinum toxin injection in Korean patients with primary achalasia and identified factors predicting remission.

METHODS

We included 73 patients with achalasia newly diagnosed between January 1988 and January 2011. We ultimately enrolled 37 of 55 patients with primary achalasia through telephone interviews, who were observed for over 1 year. Short-term outcomes were evaluated from the medical records based on symptom relief after 1 month of treatment. Long-term outcomes were evaluated in a telephone interview using a questionnaire.

RESULTS

Twenty-five patients were administered a botulinum toxin injection and 12 underwent balloon dilation. One month after the botulinum toxin injection, improvements were seen in chest pain (14 [56.0%] to 4 patients [16.0%]), regurgitation (16 [64.0%] to 4 [16.0%]), and dysphagia (25 [100.0%] to 5 [20.0%]). In the balloon dilation group, chest pain (8 [66.7%] to 1 [8.3%]), regurgitation (11 [91.7%] to 1 [8.3%]), and dysphagia (12 [100.0%] to 1 [8.3%]) had improved. A significant difference was observed in the mean remission duration between the botulinum toxin injection and balloon dilation groups (13 months [range, 1 to 70] vs. 29 months [range, 6 to 72], respectively; p = 0.036). Independent factors predicting long-term remission included treatment type (odds ratio [OR], 6.982; p = 0.036) and the difference in the lower esophageal sphincter pressure (OR, 7.198; p = 0.012).

CONCLUSIONS

Balloon dilation may be more efficacious than botulinum toxin for providing long-term remission in Korean patients with achalasia. Follow-up manometry may predict the long-term outcome.

Overview of gastrointestinal cancer prevention in Asia

"War on cancer" was declared through the National Cancer Act by President Richard Nixon in 1971, but cancer statistics from the American Cancer Society and other sources indicated the failure of this war, suggesting instead focus on the message that a "prevention strategy" might be much more effective than cancer treatment. While cancer statistics notoriously showed sharp increases in incidence as well as in mortality concurrent with economic growth in Asia, fortunately Asian countries benefit from plentiful resources of natural compounds, which can prevent cancer. Just like cancer chemotherapeutics targeted to kill cancer cells in Western countries, natural agents activating molecular mechanisms for cancer prevention, reversion of premalignant tumors, and even ablation of cancer stem cells, are very abundant in Asia. Currently, these natural agents are under very active investigations targeting the hallmarks of cancer prevention, including selective induction of apoptosis in cancer cells, suppression of growth factors or their signaling, suppression of cell proliferation and of cancer-promoting angiogenesis, induction of mesenchymal-epithelial transition, and disruption of the tumor microenvironment, developing promising cancer preventive agents. However, Asia is the most populous continent in the world and some Asian countries do not have the resources to implement cancer screening programs for early detection or treatment. In addition, despite the excellent cancer preventive screening strategies in some Asian countries, well-designed clinical trials for cancer prevention are somewhat delayed compared to Western countries. In this review article, several phytochemicals/phytoceuticals produced and studied in different Asian countries will be introduced, including Korean red ginseng (pride of Korea), curcumin (Indian spice for life), black or green tea (popular in Japan/Sri Lanka), genistein from tofu (famous Chinese food), diallylsulfide or S-allylcysteine (garlic, popularly consumed as a food ingredient in many Asian countries), capsaicin, 6-gingerol, flavopiridol, and silymarin (abundant in various Asian foods). Whereas in Western countries cancer chemotherapeutics involve strategies not only to block the growth of the primary tumor, but also to inhibit its progression to metastatic disease, the endless pursuit of effective agents for cancer prevention may be a unique and featured strategy in Asia. More active efforts for clinical application of these principles should be supported.

ESD around the world: Asia

Endoscopic submucosal dissection (ESD) improves the quality of life of patients with early gastric cancer (EGC) and dysplasia by preserving gastric function. ESD in the treatment of EGC and dysplasia has become standard in Japan and Korea and is being developed and implemented in many major centers in Asia. With a well-designed prospective study, long-term outcomes of expanded criteria for endoscopic resection of EGC are expected to provide reliable indications for endoscopic treatment. Ongoing and novel clinical investigations of minimally invasive approaches and close collaboration between Western and Asian countries are expected to establish the best way to treat EGC.

Clinical and Technical Guideline for Endoscopic Ultrasound (EUS)-Guided Tissue Acquisition of Pancreatic Solid Tumor: Korean Society of Gastrointestinal Endoscopy (KSGE)

Endoscopic ultrasound (EUS)-guided tissue acquisition of pancreatic solid tumor requires a strict recommendation for its proper use in clinical practice because of its technical difficulty and invasiveness. The Korean Society of Gastrointestinal Endoscopy (KSGE) appointed a task force to draft clinical practice guidelines for EUS-guided tissue acquisition of pancreatic solid tumor. The strength of recommendation and the level of evidence for each statement were graded according to the Minds Handbook for Clinical Practice Guideline Development 2014. The committee, comprising a development panel of 16 endosonographers and an expert on guideline development methodology, developed 12 evidence-based recommendations in eight categories intended to help physicians make evidence-based clinical judgments with regard to the diagnosis of pancreatic solid tumor. This clinical practice guideline discusses EUS-guided sampling in pancreatic solid tumor and makes recommendations on circumstances that warrant its use, technical issues related to maximizing the diagnostic yield (e.g., needle type, needle diameter, adequate number of needle passes, sample obtaining techniques, and methods of specimen processing), adverse events of EUS-guided tissue acquisition, and learning-related issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This guideline may not be applicable for all clinical situations and should be interpreted in light of specific situations and the availability of resources. It will be revised as necessary to cover progress and changes in technology and evidence from clinical practice. (Gut Liver 2021;15:-374)

The risk factors for bleeding of fundal varices in patients with liver cirrhosis

Background/Aims

The relationship between portal hemodynamics and fundal varices has not been well documented. The purpose of this study was to understand the pathophysiology of fundal varices and to investigate bleeding risk factors related to the presence of spontaneous portosystemic shunts, and to examine the hepatic venous pressure gradient (HVPG) between fundal varices and other varices.

Methods

In total, 85 patients with cirrhosis who underwent HVPG and gastroscopic examination between July 2009 and March 2011 were included in this study. The interrelationship between HVPG and the types of varices or the presence of spontaneous portosystemic shunts was studied.

Results

There was no significant difference in the HVPG between fundal varices (n=12) and esophageal varices and gastroesophageal varices type 1 (GOV1) groups (n=73) (17.1±7.7 mm Hg vs 19.7±5.3 mm Hg). Additionally, there was no significant difference in the HVPG between varices with spontaneous portosystemic shunts (n=28) and varices without these shunts (n=57) (18.3±5.8 mm Hg vs 17.0±8.1 mm Hg). Spontaneous portosystemic shunts increased in fundal varices compared with esophageal varices and GOV1 (8/12 patients [66.7%] vs 20/73 patients [27.4%]; p=0.016).

Conclusions

Fundal varices had a high prevalence of spontaneous portosystemic shunts compared with other varices. However, the portal pressure in fundal varices was not different from the pressure in esophageal varices and GOV1.

Evidence-based recommendations on upper gastrointestinal tract stenting: a report from the stent study group of the korean society of gastrointestinal endoscopy

Endoscopic stents have evolved dramatically over the past 20 years. With the introduction of uncovered self-expanding metal stents in the early 1990s, they are primarily used to palliate symptoms of malignant obstruction in patients with inoperable gastrointestinal (GI) cancer. At present, stents have emerged as an effective, safe, and less invasive alternative for the treatment of malignant GI obstruction. Clinical decisions about stent placement should be made based on the exact understanding of the patient's condition. These recommendations based on a critical review of the available data and expert consensus are made for the purpose of providing endoscopists with information about stent placement. These can be helpful for management of patients with inoperable cancer or various nonmalignant conditions in the upper GI tract.

How to predict adequate bowel preparation before colonoscopy using conventional polyethylene glycol: prospective observational study based on survey

BACKGROUND AND AIM

The present study investigated the conditions and predictive factors for adequate bowel preparation using 4-L polyethylene glycol (PEG) preparation in clinical practice.

METHODS

We conducted a prospective-survey-based observational study. The survey consisted of 14 questions that assessed the preparation method (group 1: split method for morning colonoscopy; group 2: full-volume method for same-day afternoon colonoscopy; group 3: full-volume method for next-day morning colonoscopy), dinner type and timing the day before colonoscopy, elapsed time after PEG consumption, and stool character and defecation frequency immediately before colonoscopy. Preparation status was compared using the Boston bowel preparation scale (BBPS).

RESULTS

Total of 465 surveys (391 for group 1, 55 for group 2, 19 for group 3) were conducted. Mean BBPS score was highest in group 1 and lowest in group 3 (P < 0.001). Fasting dinner before colonoscopy group showed a higher mean BBPS than the diet group; eating before 6 p.m. and a low-residue diet showed a higher mean BBPS (P < 0.05). Defecation frequency (>5 times) was related to adequate preparation in the left colon and elapsed time (<5 h) to that in the right colon (P < 0.05). Liquid stool without solid material immediately before colonoscopy was related to adequate preparation (P < 0.001).

CONCLUSION

In bowel preparation with 4-L PEG, elapsed time after PEG consumption (<5 h), defecation frequency (>5 times) and liquid stool without solid material immediately before colonoscopy were predictive factors for adequate bowel preparation just before colonoscopy.

Clinical practice guideline for endoscopic resection of early gastrointestinal cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Impedance Analysis Using High-resolution Impedance Manometry Facilitates Assessment of Pharyngeal Residue in Patients With Oropharyngeal Dysphagia

Background/Aims

Impedance analysis using high-resolution impedance manometry (HRIM) enables the recognition of pharyngeal residue in patients with oropharyngeal dysphagia. The aims of this study were to evaluate appropriate criteria for impedance analysis in a large patient cohort, as well as the diagnostic accuracy and agreement of analysis performed by HRIM trainees.

Methods

We reviewed 33 controls (13 males; median age, 61.2 years) and 104 oropharyngeal dysphagia patients (61 males; median age, 70.4 years) who underwent a flexible endoscopic evaluation of swallowing study (FEES) and HRIM. Two experts compared the pharyngeal residue on FEES and impedance color pattern at 1,000, 1,500 and 2,000 Ω of the impedance bar. Three trainees were given a 60 minutes tutorial to determine the diagnostic accuracy and agreement of this analysis.

Results

The diagnostic sensitivity of experts for predicting liquid residue was 73.1% for 1,000 Ω, 96.2% for 1,500 Ω and 100% for 2,000 Ω. Significantly higher sensitivity was observed at 1,500 Ω compared to 1,000 Ω (P < 0.001). The diagnostic specificity of experts for liquid residue was 98.3% for 1,000 Ω, 96.6% for 1,500 Ω and 83.1% for 2,000 Ω. There was a higher specificity at 1,500 Ω compared to 2,000 Ω (P = 0.008). The κ value among the 3 trainees was 0.89 and the diagnostic accuracy of the trainees for liquid residue was comparable to that of the experts.

Conclusions

The impedance analysis at 1,500 Ω provides more accurate information for the detection of liquid residue, irrespective of the level of expertise.

The Usefulness of the Measurement of Esophagogastric Junction Distensibility by EndoFLIP in the Diagnosis of Gastroesophageal Reflux Disease

Background/Aims

Increased esophagogastric junction (EGJ) relaxation is the most important mechanism involved in gastroesophageal reflux disease (GERD). An endoscopic functional luminal imaging probe (EndoFLIP^Ⓡ) is a device used to quantify EGJ distensibility in routine endoscopy. The aim of the current study was to assess the usefulness of EndoFLIP^Ⓡ for the diagnosis of GERD compared to normal controls.

Methods

We analyzed EndoFLIP^Ⓡ data from 204 patients with erosive reflux disease (ERD), 310 patients with nonerosive reflux disease (NERD), and 277 normal subjects. EndoFLIP^Ⓡ uses impedance planimetry to measure 16 cross-sectional areas (CSAs) in conjunction with the corresponding intrabag pressure within a 4.6 cm cylindrical segment of a fluid-filled bag. The EGJ distensibility was assessed using 40 mL volume-controlled distensions.

Results

The mean distensibility index values were 13.98 mm²/mm Hg in ERD patients, 11.42 mm²/mm Hg in NERD patients, and 9.1 mm²/mm Hg in normal subjects. There were significant differences in EGJ distensibility among the three groups (p<0.001). In addition, the CSAs were significantly higher in the ERD (291.03±160.77 mm²) and NERD groups (285.87±155.47 mm²) than in the control group (249.78±144.76 mm², p=0.004). We determined the distensibility index cutoff value of EGJ as 10.95 for the diagnosis of GERD by receiver operating characteristic curve analysis.

Conclusions

The EGJ distensibilities of GERD patients were higher than those of normal subjects, regardless of the presence of reflux esophagitis. Thus, the measurement of EGJ distensibility using the EndoFLIP^Ⓡ system could be useful in the diagnosis of GERD.

Endoscopic Treatment of Various Gastrointestinal Tract Defects with an Over-the-Scope Clip: Case Series from a Tertiary Referral Hospital

Recently, increasingly invasive therapeutic endoscopic procedures and more complex gastrointestinal surgeries such as endoscopic mucosal resection, endoscopic submucosal dissection, and novel laparoscopic approaches have resulted in endoscopists being confronted more frequently with perforations, fistulas, and anastomotic leakages, for which nonsurgical closure is desired. In this article, we present our experiences with the use of over-the-scope clip (OTSC) for natural orifice transluminal endoscopic surgery (NOTES) closure, prevention of perforation, anastomotic leakages, and fistula closures. The OTSC is a valuable device for closing intestinal perforations and fistulas, for NOTES closure, and for the prevention of perforation after the excision of a tumor from the proper muscle layer. Furthermore, it seems to be quite safe to perform, even by endoscopists with little experience of the technique.

Management of patients after failed peroral endoscopic myotomy: a multicenter study

BACKGROUND

Although peroral endoscopic myotomy (POEM) is highly effective for the management of achalasia, clinical failures may occur. The optimal management of patients who fail POEM is not well known. This study aimed to compare the outcomes of different management strategies in patients who had failed POEM.

METHODS

This was an international multicenter retrospective study at 16 tertiary centers between January 2012 and November 2019. All patients who underwent POEM and experienced persistent or recurrent symptoms (Eckardt score > 3) were included. The primary outcome was to compare the rates of clinical success (Eckardt score ≤ 3) between different management strategies. RESULTS : 99 patients (50 men [50.5 %]; mean age 51.4 [standard deviation (SD) 16.2]) experienced clinical failure during the study period, with a mean (SD) Eckardt score of 5.4 (0.3). A total of 29 patients (32.2 %) were managed conservatively and 70 (71 %) underwent retreatment (repeat POEM 33 [33 %], pneumatic dilation 30 [30 %], and laparoscopic Heller myotomy (LHM) 7 [7.1 %]). During a median follow-up of 10 (interquartile range 3 - 20) months, clinical success was highest in patients who underwent repeat POEM (25 /33 [76 %]; mean [SD] Eckardt score 2.1 [2.1]), followed by pneumatic dilation (18/30 [60 %]; Eckardt score 2.8 [2.3]), and LHM (2/7 [29 %]; Eckardt score 4 [1.8]; P = 0.12). A total of 11 patients in the conservative group (37.9 %; mean Eckardt score 4 [1.8]) achieved clinical success. CONCLUSION : This study comprehensively assessed an international cohort of patients who underwent management of failed POEM. Repeat POEM and pneumatic dilation achieved acceptable clinical success, with excellent safety profiles.