Performance characteristics of retrograde single-balloon endoscopy: A single center experience

AIM: To evaluate the technical success, diagnostic yield(DY) and therapeutic potential of retrograde single balloon enteroscopy(rS BE). METHODS: A retrospective review of 136 rS BE procedures performed at a tertiary academic referral center from January 2006 and September 2013 was completed. Patient characteristics including age, gender and inpatient status were collected. The indication for the procedure was categorized into one of three groups: Obscure gastrointestinal bleeding(GIB), evaluation for Crohn's disease and abnormal imaging. Procedural characteristics including insertion depth(ID), procedure time, concordance with pre-procedural imaging and complications were also recorded. Lastly, DY, defined as the percentage of cases producing either a definitive diagnosis or findings that could explain clinical symptoms and therapeutic yield(TY), defined as the percentage of cases in which a definitive intervention was performed, were determined. Mucosal tattooing and biopsy alone were not included in the TY. RESULTS: A total of 136 rS BE procedures were identified. Mean patient age was 57.5(± 16.2) years, 67(49.2%) were male, and 110(80.9%) procedures were performed on an outpatient basis. Indications for rS BE included GIB in 55(40.4%), evaluation of inflammatory bowel disease(IBD) in 29(21.3%), and imaging suggestive of pathology other than GIB or IBD in 43(31.6%). Nine(6.6%) rS BEs were performed for other indications. Mean ID was 68.3(± 39.3) cm proximal to the ileocecal valve and mean time to completion was 41.7(± 15.5) min. Overall, 73(53.7%) cases were diagnostic and 25(18.4%) cases were therapeutic in which interventions(argon plasma coagulation, stricture dilatation, polypectomy, etc.) were performed. Pre-procedural imaging was performed in 88(64.7%) patients. Endoscopic concordance of positive imaging findings was seen in 31(35.2%) cases. Follow up data was available in 93(68.4%) patients; 2(2.2%) reported post-procedural abdominal pain within 30 d following rS BE. There were no other reported complications. CONCLUSION: rS BE exhibits an acceptable diagnostic and TY, rendering it a safe and effective procedure for the evaluation and treatment of small bowel diseases.

Clinical usefulness of single-balloon endoscopy in patients with previously incomplete colonoscopy

AIM:To evaluate the clinical usefulness of singleballoon endoscopy(SBE) in patients in whom a colonoscope was technically difficult to insert previously.METHODS:The study group comprised 15 patients(8 men and 7 women) who underwent SBE for colonoscopy(30 sessions).The number of SBE sessions was 1 in 7 patients,2 in 5 patients,3 in 1 patient,4 in 1 patient,and 6 in 1 patient.In all patients,total colonoscopy was previously unsuccessful.The reasons for difficulty in scope passage were an elongated colon in 6 patients,severe intestinal adhesions after open surgery in 4,an elongated colon and severe intestinal adhesions in 2,a left inguinal hernia in 2,and multiple diverticulosis of the sigmoid colon in 1.Three endoscopists were responsible for SBE.The technique for inserting SBE in the colon was basically similar to that in the small intestine.The effectiveness of SBE was assessed on the basis of the success rate of total colonoscopy and the presence or absence of complications.We also evaluated the diagnostic and treatment outcomes of colonoscopic examinations with SBE.RESULTS:Total colonoscopy was successfully accomplished in all sessions.The mean insertion time to the cecum was 22.9 ± 8.9 min(range 9 to 40).Abnormalities were found during 21 sessions of SBE.The most common abnormality was colorectal polyps(20 sessions),followed by radiation colitis(3 sessions) and diverticular disease of the colon(3 sessions).Colorectal polyps were resected endoscopically in 15 sessions.A total of 42 polyps were resected endoscopically,using snare polypectomy in 32 lesions,hot biopsy in 7 lesions,and endoscopic mucosal resection in 3 lesions.Fifty-six colorectal polyps were newly diagnosed on colonoscopic examination with SBE.Histopathologically,these lesions included 2 intramucosal cancers,42 tubular adenomas,and 2 tubulovillous adenomas.The mean examination time was 48.2 ± 20.0 min(range 25 to 90).Colonoscopic examination or endoscopic treatment with SBE was not associated with any serious complications.CONCLUSION:SBE is a useful and safe procedure in patients in whom a colonoscope is technically difficult to insert.

Role of second look endoscopy in endoscopic submucosal dissection and peptic ulcer bleeding:Meta-analysis of randomized controlled trials

BACKGROUND Second-look endoscopy(SLE)to prevent recurrent bleeding in patients with peptic ulcer disease(PUD)and those undergoing endoscopic submucosal dissection(ESD)is routinely being performed.Conflicting evidence exists regarding efficacy,risk,benefit,and cost-effectiveness.AIM To identify the role and effectiveness of SLE in ESD and PUD,associated rebleeding and PUD-related outcomes like mortality,hospital length of stay,need for endoscopic or surgical intervention and blood transfusions.METHODS A systematic review of literature databases PubMed,Cochrane,and Embase was conducted from inception to January 5,2023.Randomized controlled trials that compared patients with SLE to those who did not have SLE or evaluated the role of prophylactic hemostasis during SLE compared to other conservative interventions were included.The study was conducted per PRISMA guidelines,and the protocol was registered in PROSPERO(ID CRD42023427555:).RevMan was used to perform meta-analysis,and Mantel-Haenszel Odds ratio(OR)were generated using random effect models.RESULTS A total of twelve studies with 2687 patients were included in our systematic review and meta-analysis,of which 1074 patients underwent SLE after ESD and 1613 patients underwent SLE after PUD-related bleeding.In ESD,the rates of rebleeding were 7%in the SLE group compared to 4.4%in the non-SLE group with OR 1.65,95%confidence intervals(CI)of 0.96 to 2.85;P=0.07,whereas it was 11%in the SLE group compared to 13%in the non-SLE group with OR 0.895%CI:0.50 to 1.29;P=0.36.The mean difference in the blood transfusion rates in the SLE and no SLE group in PUD was OR 0.01,95%CI:-0.22 to 0.25;P=0.91.In SLE vs non-SLE groups with PUD,the OR for Endoscopic intervention was 0.29,95%CI:0.08 to 1.00;P=0.05 while it was OR 2.03,95%CI:0.95 to 4.33;P=0.07,for surgical intervention.The mean difference in the hospital length of stay was-3.57 d between the SLE and no SLE groups in PUD with 95%CI:-7.84 to 0.69;P=0.10,denoting an average of approximately 3 fewer days of hospital stay among patients with PUD who underwent SLE.For mortality between SLE and non-SLE groups in PUD,the OR was 0.88,95%CI:0.45 to 1.72;P=0.70.CONCLUSION SLE does not confer any benefit in preventing ESD and PUD-associated rebleeding.SLE also does not provide any significant improvement in mortality,need for interventions,or blood transfusions in PUD patients.SLE decreases the hospital length of stay on average by 3.5 d in PUD patients.

Capsule endoscopy:Do we still need it after 24 years of clinical use?

In this letter,we comment on a recent article published in the World Journal of Gastroenterology by Xiao et al,where the authors aimed to use a deep learning model to automatically detect gastrointestinal lesions during capsule endoscopy(CE).CE was first presented in 2000 and was approved by the Food and Drug Administration in 2001.The indications of CE overlap with those of regular diagnostic endoscopy.However,in clinical practice,CE is usually used to detect lesions in areas inaccessible to standard endoscopies or in cases of bleeding that might be missed during conventional endoscopy.Since the emergence of CE,many physiological and technical challenges have been faced and addressed.In this letter,we summarize the current challenges and briefly mention the proposed methods to overcome these challenges to answer a central question:Do we still need CE?

Gel immersion in endoscopy:Exploring potential applications

The challenge of effectively eliminating air during gastrointestinal endoscopy using ultrasound techniques is apparent.This difficulty arises from the intricacies of removing concealed air within the folds of the gastrointestinal tract,resulting in artifacts and compromised visualization.In addition,the overlap of folds with lesions can obscure their depth and size,presenting challenges for an accurate assessment.Conversely,in intricately folded regions of the gastrointestinal tract,such as the stomach,intestine,and colon,insufficient delivery of air or CO_(2) into the cavity impedes luminal expansion,hindering the accurate visualization of lesions concealed within the folds.Although this underscores the requirement for substantial airflow,excessive airflow can hinder visualization of bleeding lesions and other abnormalities.Considering these challenges,an ideal endoscopic device would facilitate the observation of lesions without the requirement for air or CO_(2) delivery whereas,ensuring optimal expansion of the gastrointestinal tract.Recently,transparent gels with specific viscosities have been employed more frequently to address this issue.This review aims to elucidate how these gels address these challenges and provide a solution for enhanced endoscopic visualization.

Preliminary study on the clinical value of endoscopic stricturotomy in the treatment of stricturing Crohn's disease

BACKGROUND Crohn's disease(CD)frequently leads to intestinal strictures,which pose significant challenges due to their complexity and limited treatment options.While medications can address inflammatory strictures,they are largely ineffective for fibrotic and mixed strictures,often necessitating surgical intervention.However,surgery carries considerable risks,including bleeding,infection,anastomotic leaks,and postoperative restricture formation.Endoscopic treatment,particularly endoscopic stricturotomy,offers a minimally invasive alternative that bridges the gap between medication and surgery.AIM To investigate the safety and efficacy of stricturotomy under single-balloon enteroscopy in stricturing CD.METHODS Patients diagnosed with stricturing CD at The First People's Hospital of Changzhou from June 2020 to April 2024 were enrolled and underwent endoscopic stricturotomy(ES).Relevant clinical data of patients were collected retrospectively.Outcomes included success rate,remission time,complications,and follow-up interventions.This observational study was followed up postoperatively to observe patient remission and recurrence rates.RESULTS Seventeen endoscopic strictures were created in 11 patients,achieving a 100%immediate success rate without any serious complications.During the follow-up period,stricture recurrence was observed in two patients,resulting in an endoscopic reintervention rate of 18.2%.Additionally,two patients required subsequent surgical intervention,with a surgical treatment rate of 18.2%.One patient experienced bowel obstruction 18 months post-ES and was successfully managed with conservative treatment without surgical intervention.The remission duration after the initial ES treatment was 10.1±8.2 months,with a median remission time of 10 months.CONCLUSION ES is a safe and effective treatment for CD-related strictures and warrants further clinical promotion and application.

Bibliometric analysis on the top one hundred cited studies on gastrointestinal endoscopy

BACKGROUND Gastrointestinal endoscopy has been widely used in the diagnosis and treatment of gastrointestinal diseases.A great many of studies on gastrointestinal endoscopy have been done.AIM To analyze the characteristics of top 100 cited articles on gastrointestinal endoscopy.METHODS A bibliometric analysis was conducted.The publications and their features were extracted from the Web of Science Core Collection,Science Citation Index-Expanded database.Excel,Web of Science database and SPSS software were used to perform the statistical description and analysis.VOSviewer software and Map-Chart were responsible for the visualizations.RESULTS The top 100 cited articles were published between 1976 and 2022.The guidelines(52%)and clinical trials(37%)are the main article types,and average publication year of the guidelines is much later than that of the clinical trials(2015 vs 1998).Among the clinical trials,diagnostic study(27.0%),cohort study(21.6%),case series(13.5%)and cross-sectional study(10.8%)account for a large proportion.Average citations of different study types and designs of the enrolled studies are of no significant differences.Most of the 100 articles were published by European authors and recorded by the endoscopic journals(65%).Top journals in medicine,such as the Lancet,New England Journal of Medicine and JAMA,also reported studies in this field.The hot spots of involved diseases include neoplasm or cancer-related diseases,inflammatory diseases,obstructive diseases,gastrointestinal hemorrhage and ulcer.Endoscopic surgery,endoscopic therapy and stent placement are frequently studied.CONCLUSION Our research contributes to delineating the field and identifying the characteristics of the most highly cited articles.It is noteworthy that there is a significantly smaller number of clinical trials included compared to guidelines,indicating potential areas for future high-quality clinical trials.

Evaluating the predictive value of endoscopic findings for residual colorectal cancer following neoadjuvant combination immunotherapy

BACKGROUND Endoscopy allows for the direct observation of primary tumor characteristics and responses after neoadjuvant treatment.However,reports on endoscopic evaluation following neoadjuvant immunotherapy remain limited.AIM To examine the predictive value of endoscopic findings of primary tumors for responses to neoadjuvant immunotherapy.METHODS This retrospective study,conducted at a tertiary center in China,evaluated 74 patients with colorectal cancer,including 17 with deficient mismatch repair(dMMR)and 15 with proficient mismatch repair(pMMR)tumors.Patients underwent neoadjuvant immunotherapy followed by surgery.Endoscopic findings before and after neoadjuvant immunotherapy were reviewed and compared with the pathology of the resected specimens.RESULTS In the pMMR group(n=57 evaluable patients),endoscopy identified 11/17 patients who achieved a complete response(CR),while misidentifying 1/40 patients with residual disease as CR(64.7%vs 2.5%,P<0.01).Conversely,22/40 patients with residual disease were accurately identified as achieving a partial response(PR),with 1/17 patients who achieved CR misclassified as PR(55.0%vs 5.9%,P<0.01).The sensitivity,specificity,and accuracy of endoscopic diagnosis for pathological CR were 64.7%,97.5%,and 87.7%,respectively.In the dMMR cohort,endoscopy classified 9/17 patients as CR and 2 of the remaining patients with residual tumors as PR(64.3%vs 66.7%,P=0.73).The method demonstrated 100%sensitivity and 82.4%accuracy in diagnosing pathological CR.CONCLUSION Endoscopic evidence of CR or PR was well correlated with postoperative pathological outcomes in the pMMR cohort.Despite endoscopic indications of tumor residue,a complete pathological response post-surgery was possible in the dMMR cohort.

Capsule endoscopy and single-balloon enteroscopy in small bowel diseases: Competing or complementary?

AIM To evaluate diagnostic yields of capsule endoscopy(CE) and/or single-balloon enteroscopy(SBE) in patients with suspected small bowel diseases.METHODS Were trospectively analyzed 700 patients with suspected small bowel diseases from September 2010 to March 2016. CE, SBE, or SBE with prior CE was performed in 401, 353, and 47 patients, respectively. Data from clinical and endoscopy records were collected for analysis. Indications, procedure times, diagnostic yields, and complications were summarized and evaluated.RESULTS The overall diagnostic yield for the CE group was 57.6%. The diagnostic yield of CE in patients with obscure gastroin testinal bleeding(OGIB) was significantly greater than that in patients with no bleeding(70.5% vs 43.8%, P < 0.01). The overall diagnostic yield of SBE was 69.7%. There was no difference in the diagnostic yield of SBE between patients with OGIB and those with no bleeding(72.5% vs 68.9%, P = 0.534). Forty-seven patients underwent CE prior to SBE. Among them, the diagnostic yield of SBE with positive findings on prior CE was 93.3%. In addition, SBE detected two cases with superficial ulcer and erosive lesions in the small bowel, which were missed by CE. However, one case with lymphoma and two with Crohn's disease were not confirmed by SBE. The rate of capsule retention was 2.0%. There were no significant complications during or after SBE examinations.CONCLUSION SBE is a safe and effective technique for diagnosing small bowel diseases. SBE with prior CE seemed to improve the diagnostic yield of small bowel diseases.

Submucosal tunnel endoscopy:Peroral endoscopicmyotomy and peroral endoscopic tumor resection

Peroral endoscopic myotomy(POEM) is an innovative,minimally invasive, endoscopic treatment for esophageal achalasia and other esophageal motility disorders, emerged from the natural orifice transluminal endoscopic surgery procedures, and since the first human case performed by Inoue in 2008, showed exciting results in international level, with more than 4000 cases globally up to now. POEM showed superior characteristics than the standard 100-year-old surgical or laparoscopic Heller myotomy(LHM), not only for all types of esophageal achalasia [classical(Ⅰ), vigorous(Ⅱ), spastic(Ⅲ), Chicago Classification], but also for advanced sigmoid type achalasia(S1 and S2), failed LHM, or other esophageal motility disorders(diffuse esophageal spasm, nutcracker esophagus or Jackhammer esophagus). POEM starts with a mucosal incision, followed by submucosal tunnel creation crossing the esophagogastric junction(EGJ) and myotomy. Finally the mucosal entry is closed with endoscopic clip placement. POEM permitted relatively free choice of myotomy length and localization. Although it is technically demanding procedure, POEM can be performed safely and achieves very good control of dysphagia and chest pain. Gastroesophageal reflux is the most common troublesome side effect, and is well controllable with proton pump inhibitors. Furthermore, POEM opened the era of submucosal tunnel endoscopy, with many other applications. Based on the same principles with POEM, in combination with new technological developments, such as endoscopic suturing, peroral endoscopic tumor resection(POET), is safely and effectively applied for challenging submucosal esophageal, EGJ and gastric cardia tumors(submucosal tumors), emerged from muscularis propria. POET showed up to know promising results, however, it is restricted to specialized centers. The present article reviews the recent data of POEM and POET and discussed controversial issues that need further study and future perspectives.

Second-look endoscopy with prophylactic hemostasis is still effective after endoscopic submucosal dissection for gastric neoplasm

AIM: The clinical value of second-look endoscopy(SLE) after endoscopic submucosal dissection(ESD) has been doubted continuously. The aim of this study was to assess the effectiveness of SLE based on the risk of delayed bleeding after ESD. METHODS: A total of 310 lesions of gastric epithelial neoplasms treated by ESD were reviewed. The lesions were divided into two groups based on the risk of postprocedural bleeding estimated by Forrest classification. The high risk of rebleeding group(Forrest?Ⅰa,?Ⅰb and Ⅱa) required endoscopic treatment, while the low risk of rebleeding group(Forrest Ⅱb, Ⅱc and Ⅲ) did not. Delayed bleeding after ESD was investigated. RESULTS: Sixty-six lesions were included in the high risk of rebleeding group and 244 lesions in the low risk of rebleeding group. There were no significant differences in delayed bleeding between the high risk group(1/66) and the low risk group(1/244)(P = 0.38). The high risk of rebleeding group tended to be located more often in the mid-third and had higher appearance of flat or depressed shape than the low risk group(P = 0.004 and P = 0.006, respectively). CONCLUSION: SLE with pre-emptive prophylactic endoscopic treatment is still effective in preventing delayed bleeding after ESD.

Premedication with pronase or N-acetylcysteine improves visibility during gastroendoscopy: An endoscopist-blinded, prospective, randomized study

AIM： To assess the efficacy of premedicaton with pronase or N-acetylcysteine （NAC） at 20 min before upper gastrointestinal （UGI） endoscopy and to determine whether pronase or NAC pretreatment influences the reliability of the rapid urease test. METHODS： A total of 146 patients were prospectively and randomly assigned into the study groups according to different premedications before endoscopy. One endoscopist assessed mucosal visibility （MV） with scores ranged from 1 to 4 at four sites in the stomach. The sum of the MV scores from these four locations was defined as the total mucosal visibility （TMV） score. Identification of Hpylori was performed using CLO test, histology, and serology. RESULTS： The Group with pronase premedication had a significantly lower TMV score than did the groups with gascon and gascon water （P 〈 0.001 and P 〈 0.01, respectively）. The group with NAC had a significantly lower TMV score than the group with gascon （P 〈 0.01） and a trend of a lower MV score than the group with gascon water （P = 0.06）. The THV score did not significantly differ between the group with pronase and the group with NAC （P = 0.39 and P = 0.14, respectively）. The sensitivity and specifidty of the CLO test were 92.5% and 93.9%, respectively, in groups premedicated with pronase and NAC together.CONCLUSION： Premedication with pronase or NAC at 20 min before UGI endoscopy improves the mucosal visibility of the stomach. Neither pronase nor NAC produces any obvious interference with the CLO test for the identification of H pylori infection.

Serrated polyps of the colon and rectum: Endoscopic features including image enhanced endoscopy

In this review, I outline the characteristic endoscopic findings of serrated lesions of the colorectum based on image enhanced endoscopy(IEE). Histopathologically, lesions with serrated structures are typically classified into the following three types based: hyperplastic polyps(HPs), traditional serrated adenomas(TSAs), and sessile serrated adenoma/polyps(SSA/Ps). Both HP and SSA/P often present as dark-green colors on auto fluorescence imaging(AFI) colonoscopy that are similar to the normal surrounding mucosa. In contrast, TSAs often have elevated shapes and present as magenta colors that are similar to the tubular adenomas. The superficial type of TSA also includes many lesions that present as magenta colors. When SSA/Ps are associated with cytological dysplasia, many lesions present with magenta colors, whereas lesions that are not associated with cytological dysplasia present with dark-green colors. When observed via narrow band imaging(NBI), many SSA/P include lesions with strong mucous adhesions. Because these lesions are observed with reddish mucous adhesions, we refer to them as "red cap sign" and place such signs among the typical findings of SSA/P. Because the dilatation of the pit in SSA/P is observed as a round/oval black dot on magnified observations, we refer to this finding as Ⅱ-dilatation pit(Ⅱ-D pit) and also positioned it as a characteristic finding of SSA/P. In contrast, dilatations of the capillary vessels surrounding the glands, such as those that occur in tubular adenoma, are not considered to be useful for differentiating HPs from SSA/Ps. However, in cases in which SSA/P is associated with cytological dysplasia, the dilatation of capillary vessels is observed in the same area. When submucosal layer invasion occurs in the same area, the blood flow presents with irregularities that are similar to those of common colorectal cancer at an early stage and disappears as the invasion proceeds deeply. The surface pattern of invasive cancer that is observed at the tumor surface is also likely to disappear. Based on the above results, we considered that the differentiations between HP and TSA, between TSA and SSA/P, and between HP and SSA/P might become easier due to the concomitant use of white light observation and IEE. We also concluded that AFI and NBI can be useful modalities for SSA/P lesions associated with cytological dysplasia.

Utility of endoscopic ultrasound and endoscopy in diagnosis and management of hepatocellular carcinoma and its complications: What does endoscopic ultrasonography offer above and beyond conventional cross-sectional imaging?

Hepatocellular carcinoma constitutes over 90% of the primary liver tumors, the rest being cholangiocarcinoma. It has an insidious presentation, which is responsible for the delayed presentation. Hence, the management strategy relies on screening to diagnose it an early stage for curative resection and/or treatment with local ablative techniques or chemotherapy. However, even with different screening programs, more than 60% of tumors are still detected at an advanced stage, leading to an unchanged mortality rate, thereby implying a room for improvement in the screening and diagnostic process. In the last few years, there has been evolution of utility of endoscopy, specifically endoscopic ultrasonography along with Fine needle aspiration, for this purpose, which we comprehensively review in this article.

Management of gastric variceal bleeding:Role of endoscopy and endoscopic ultrasound

Gastric varices(GVs)are notorious to bleed massively and often difficult to manage with conventional techniques.This mini-review addresses endoscopic management principles for gastric variceal bleeding,including limitations of ligation and sclerotherapy and merits of endoscopic variceal obliteration.The article also discusses how emerging use of endoscopic ultrasound provides optimism of better diagnosis,improved classification,innovative management strategies and confirmatory tool for eradication of GVs.

Percutaneous endoscopic gastrostomy under steadypressure automatically controlled endoscopy:First clinicalseries

AIM: To elucidate the safety of percutaneous endoscopic gastrostomy(PEG) under steady pressure automatically controlled endoscopy(SPACE) using carbon dioxide(CO_2).METHODS: Nine patients underwent PEG with a modified introducer method under conscious sedation. A T-tube was attached to the channel of an endoscope connected to an automatic surgical insufflator. The stomach was inflated under the SPACE system. The intragastric pressure was kept between 4-8 mmH g with a flow of CO_2 at 35 L/min. Median procedure time, intragastric pressure, median systolic blood pressure, partial pressure of CO_2, abdominal girth before and immediately after PEG, and free gas and small intestinal gas on abdominal X-ray before and after PEG were recorded. RESULTS: PEG was completed under stable pneumostomach in all patients, with a median procedural time of 22 min. Median intragastric pressure was 6.9 mmH g and median arterial CO_2 pressure before and after PEG was 42.1 and 45.5 Torr(NS). The median abdominal girth before and after PEG was 68.1 and 69.6 cm(NS). A mild free gas image after PEG was observed in two patients, and faint abdominal gas in the downstream bowel was documented in two patients.CONCLUSION: SPACE might enable standardized pneumostomach and modified introducer procedure of PEG.

Image-enhanced endoscopy for diagnosis of colorectal tumors in view of endoscopic treatment

Recently,image-enhanced endoscopy(IEE) has been used to diagnose gastrointestinal tumors.This method is a change from conventional white-light(WL) endoscopy without dyeing solution,requiring only the push of a button.In IEE,there are many advantages in diagnosis of neoplastic tumors,evaluation of invasion depth for cancerous lesions,and detection of neoplastic lesions.In narrow band imaging(NBI) systems(Olympus Medical Co.,Tokyo,Japan),optical filters that allow narrow-band light to pass at wavelengths of 415 and 540 nm are used.Mucosal surface blood vessels are seen most clearly at 415 nm,which is the wavelength that corresponds to the hemoglobin absorption band,while vessels in the deep layer of the mucosa can be detected at 540 nm.Thus,NBI also can detect pit-like structures named surface pattern.The flexible spectral imaging color enhancement(FICE) system(Fujifilm Medical Co.,Tokyo,Japan) is also an IEE but different to NBI.FICE depends on the use of spectral-estimation technology to reconstruct images at different wavelengths based on WL images.FICE can enhance vascular and surface patterns.The autofluorescence imaging(AFI) video endoscope system(Olympus Medical Co.,Tokyo,Japan) is a new illumination method that uses the difference in intensity of autofluorescence between the normal area and neoplastic lesions.AFI light comprises a blue light for emitting and a green light for hemoglobin absorption.The aim of this review is to highlight the efficacy of IEE for diagnosis of colorectal tumors for endoscopic treatment.

Ling classification describes endoscopic progressive process of achalasia and successful peroral endoscopy myotomy prevents endoscopic progression of achalasia

AIM To verify the hypothesis that the Ling classification describes the endoscopic progressive process of achalasia and determine the ability of successful peroral endoscopic myotomy (POEM) to prevent endoscopic progression of achalasia. METHODS We retrospectively reviewed the endoscopic findings, symptom duration, and manometric data in patients with achalasia. A total of 359 patients (197 women, 162 men) with a mean age of 42.1 years (range, 12-75 years) were evaluated. Symptom duration ranged from 2 to 360 mo, with a median of 36 mo. Patients were classified with Ling type I (n = 119), II a (n = 106),II b (n = 60),II c (n = 60), or III (n = 14), according to the Ling classification. Of the 359 patients, 349 underwent POEM, among whom 21 had an endoscopic follow-up for more than 2 years. Pre-treatment and post-treatment Ling classifications of these 21 patients were compared. RESULTS Symptom duration increased significantly with increasing Ling classification (from I to III) (p < 0.05), whereas lower esophageal sphincter pressure decreased with increasing Ling type (from I to III) (p < 0.05). There was no difference in sex ratio or onset age among the Ling types, although the age at time of diagnosis was higher in Ling types I c and III than in Ling types I, IIa, and I b. Of the 21 patients, 19 underwent high-resolution manometry both before and after treatment. The mean preoperative and postoperative lower esophageal sphincter pressure were 34.6 mmHg (range, 15.3-59.4 mmHg) and 15.0 mmHg (range, 2.1-21.6 mmHg), respectively, indicating a statistically significant decrease after POEM. All of the 21 patients were treated successfully by POEM (postoperative Eckardt score <= 3) and still had the same Ling type during a mean follow-up period of 37.8 mo (range, 24-51 mo). CONCLUSION The Ling classification represents the endoscopic progressive process of achalasia and may be able to serve as an endoscopic assessment criterion for achalasia. Successful POEM (Eckardt score <= 3) seems to have the ability to prevent endoscopic evolvement of achalasia. However, studies with larger populations are warranted to confirm our findings.

Magnifying endoscopy in upper gastroenterology for assessing lesions before completing endoscopic removal

Any prognosis of gastrointestinal (GI) cancer is closely related to the stage of the disease at diagnosis.Endoscopic submucosal dissection (ESD) and en bloc endoscopic mucosal resection (EMR) have been performed as curative treatments for many early-stage GI lesions in recent years.The technologies have been widely accepted in many Asian countries because they are minimally invasive and supply thorough histopathologic evaluation of the specimens.However,before engaging in endoscopic therapy,an accurate diagnosis is a precondition to effecting the complete cure of the underlying malignancy or carcinoma in situ.For the past few years,many new types of endoscopic techniques,including magnifying endoscopy with narrow-band imaging (MENBI),have emerged in many countries because these methods provide a strong indication of early lesions and are very useful in determining treatment options before ESD or EMR.However,to date,there is no comparable classification equivalent to "Kudo's Pit Pattern Classification in the colon",for the upper GI,there is still no clear internationally accepted classification system of magnifying endoscopy.Therefore,in order to help unify some viewpoints,here we will review the defining optical imaging characteristics and the current representative classifications of microvascular and microsurface patterns in the upper GI tract under ME-NBI,describe the accurate relationship between them and the pathological diagnosis,and their clinical applications prior to ESD or en bloc EMR.We will also discuss assessing the differentiation and depth of invasion,defying the lateral spread of involvement and targeting biopsy in real time.

Conventional colonoscopy and magnified chromoendoscopy for the endoscopic histological prediction of diminutive colorectal polyps: A single operator study

AIM： To accurately differentiate the adenomatous from the non-adenomatous polyps by colonoscopy. METHODS： All lesions detected by colonoscopy were first diagnosed using the conventional view followed by chromoendoscopy with magnification. The diagnosis at each step was recorded consecutively. All polyps were completely removed endoscopically for histological evaluation. The accuracy rate of each type of endoscopic diagnosis was evaluated, using histological findings as gold standard. RESULTS： A total of 240 lesions were identified, of which 158 （65.8%） were non-neoplastic and 82 （34.2%） were adenomatous. The overall diagnostic accuracy of conventional view, and chromoendoscopy with magnification was 76.3% （183/240） and 95.4% （229/240）, respectively （P〈 0.001） CONCLUSION： The combination of colonoscopy and magnified chromoendoscopy is the most reliable nonbiopsy method for distinguishing the non-neoplastic from the neoplastic lesions.