Comparison of high resolution magnifying endoscopy and standard videoendoscopy for the diagnosis of Helicobacter pylori gastritis in routine clinical practice: a prospective study

Novel endoscopic techniques for the diagnosis of gastric Helicobacter pylori infection: a systematic review and network meta-analysis

Objective

This study aimed to conduct a network meta-analysis to compare the diagnostic efficacy of diverse novel endoscopic techniques for detecting gastric Helicobacter pylori infection.

Methods

From inception to August 2023, literature was systematically searched across Pubmed, Embase, and Web of Science databases. Cochrane's risk of bias tool assessed the methodological quality of the included studies. Data analysis was conducted using the R software, employing a ranking chart to determine the most effective diagnostic method comprehensively. Convergence analysis was performed to assess the stability of the results.

Results

The study encompassed 36 articles comprising 54 observational studies, investigating 14 novel endoscopic techniques and involving 7,230 patients diagnosed with gastric H. pylori infection. Compared with the gold standard, the comprehensive network meta-analysis revealed the superior diagnostic performance of two new endoscopic techniques, Magnifying blue laser imaging endoscopy (M-BLI) and high-definition magnifying endoscopy with i-scan (M-I-SCAN). Specifically, M-BLI demonstrated the highest ranking in both sensitivity (SE) and positive predictive value (PPV), ranking second in negative predictive value (NPV) and fourth in specificity (SP). M-I-SCAN secured the top position in NPV, third in SE and SP, and fifth in PPV.

Conclusion

After thoroughly analyzing the ranking chart, we conclude that M-BLI and M-I-SCAN stand out as the most suitable new endoscopic techniques for diagnosing gastric H. pylori infection.

Systematic review registration

https://inplasy.com/inplasy-2023-11-0051/, identifier INPLASY2023110051.

The Diagnostic Performance of Linked Color Imaging Compared to White Light Imaging in Endoscopic Diagnosis of Helicobacter pylori Infection: A Systematic Review and Meta-Analysis

Background/Aims

Recognizing Helicobacter pylori infection during endoscopy is important because it can lead to the performance of confirmatory testing. Linked color imaging (LCI) is an image enhancement technique that can improve the detection of gastrointestinal lesions. The purpose of this study was to compare LCI to conventional white light imaging (WLI) in the endoscopic diagnosis of H. pylori infection.

Methods

We conducted a comprehensive literature search using PubMed, Embase, and the Cochrane Library. All studies evaluating the diagnostic performance of LCI or WLI in the endoscopic diagnosis of H. pylori were eligible. Studies on magnifying endoscopy, chromoendoscopy, and artificial intelligence were excluded.

Results

Thirty-four studies were included in this meta-analysis, of which 32 reported the performance of WLI and eight reported the performance of LCI in diagnosing H. pylori infection. The pooled sensitivity and specificity of WLI in the diagnosis of H. pylori infection were 0.528 (95% confidence interval [CI], 0.517 to 0.540) and 0.821 (95% CI, 0.811 to 0.830), respectively. The pooled sensitivity and specificity of LCI in the diagnosis of H. pylori were 0.816 (95% CI, 0.790 to 0.841) and 0.868 (95% CI, 0.850 to 0.884), respectively. The pooled diagnostic odds ratios of WLI and LCI were 15.447 (95% CI, 8.225 to 29.013) and 31.838 (95% CI, 15.576 to 65.078), respectively. The areas under the summary receiver operating characteristic curves of WLI and LCI were 0.870 and 0.911, respectively.

Conclusions

LCI showed higher sensitivity in the endoscopic diagnosis of H. pylori infection than standard WLI.

Regular arrangement of collecting venules (RAC) as an endoscopic marker for exclusion of Helicobacter pylori (H. pylori) infection: A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori) is the most common cause of gastric cancer. Growing evidence suggests that the regular arrangement of collecting venules (RAC) can be used as an endoscopic marker to diagnose H. pylori infection. However, data on the diagnostic accuracy of RAC for H. pylori infection are conflicting. We performed a systematic review and meta-analysis of relevant studies to determine the diagnostic accuracy and clinical utility of RAC for the diagnosis of H. pylori infection.

METHODS

We systematically searched PubMed, Embase, Web of Science and the Cochrane Library between inception and Oct 29, 2020, for studies that assessed the diagnostic accuracy of RAC for H. pylori infection.

RESULTS

The literature search yielded 2921 non-duplicated screened titles, of which 58 underwent full-text review. Fifteen studies, representing a total of 6621 patients, met the inclusion criteria. The area under the summary receiver operating characteristic curve was 0.98 (95% CI 0.96-0.99). The pooled estimates for RAC were 0.98 (95% CI 0.95-0.99) for sensitivity and 0.75 (95% CI 0.54-0.88) for specificity. The pooled positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 3.8 (95% CI 1.9-7.7) and 0.03 (95% CI 0.02-0.07), respectively.

CONCLUSIONS

RAC can be used as an endoscopic marker for exclusion of H. pylori infection. However, it cannot be recommended as a single indicator for the confirmation of H. pylori infection. The conclusion of this study should be treated with caution because significant heterogeneity exists between the evaluated studies.

Association between regular arrangement of collecting venules and Helicobacter pylori status in routine endoscopy

Background

The sensitivity of regular arrangement of collecting venules (RAC)-positive pattern for predicting Helicobacter pylori (H. pylori)-negative status greatly altered from 93.8 to 48.0% in recent two decades of various studies, while the reason behind it remained obscure. The aim of this study was to investigate the value of RAC as an endoscopic feature for judging H. pylori status in routine endoscopy and reviewed the underlying mechanism.

Methods

A prospective study with high-definition non-magnifying endoscopy was performed. RAC-positive and RAC-negative patients were classified according to the collecting venules morphology of the lesser curvature in gastric corpus. Gastric biopsy specimens were obtained from the lesser and greater curvature of corpus with normal RAC-positive or abnormal RAC-negative mucosal patterns. Helicobacter pylori status was established by hematoxylin and eosin staining and immunohistochemistry.

Results

41 RAC-positive and 124 RAC-negative patients were enrolled from June 2020 to September 2020. The prevalence of H. pylori infection in patients with RAC-positive pattern and RAC-negative pattern was 7.3% (3/41) and 71.0% (88/124), respectively. Among all 124 RAC-negative patients, 36 (29.0%) patients were H. pylori-negative status. Ten patients (32.3%) demonstrated RAC-positive pattern in 31 H. pylori-eradicated cases. The sensitivity, specificity, positive predictive value, and negative predictive value of RAC-positive pattern for predicting H. pylori-negative status were 51.4% (95% CI, 0.395–0.630), 96.7% (95% CI, 0.900–0.991), 92.7% (95% CI, 0.790–0.981), and 71.0% (95% CI, 0.620–0.786), respectively.

Conclusions

RAC presence can accurately rule out H. pylori infection of gastric corpus, and H. pylori-positive status cannot be predicted only by RAC absence in routine endoscopy.

Trial registration The present study is a non-interventional trial.

Association between mucosal surface pattern under near focus technology and Helicobacter pylori infection

BACKGROUND

Many studies evaluated magnification endoscopy (ME) to correlate changes on the gastric mucosal surface with Helicobacter pylori (H. pylori) infection. However, few studies validated these concepts with high-definition endoscopy without ME.

AIM

To access the association between mucosal surface pattern under near focus technology and H. pylori infection status in a western population.

METHODS

Cross-sectional study including all patients referred to routine upper endoscopy. Endoscopic exams were performed using standard high definition (S-HD) followed by near focus (NF-HD) examination. Presence of erythema, erosion, atrophy, and nodularity were recorded during S-HD, and surface mucosal pattern was classified using NF-HD in the gastric body. Biopsies were taken for rapid urease test and histology.

RESULTS

One hundred and eighty-seven patients were analyzed from August to November 2019. Of those, 47 (25.1%) were H. pylori+, and 42 (22.5%) had a previous H. pylori treatment. In the examination with S-HD, erythema had the best sensitivity for H. pylori detection (80.9%). Exudate (99.3%), nodularity (97.1%), and atrophy (95.7%) demonstrated better specificity values, but with low sensitivity (6.4%-19.1%). On the other hand, the absence of erythema was strongly associated with H. pylori- (negative predictive value = 92%). With NF-HD, 56.2% of patients presented type 1 pattern (regular arrangement of collecting venules, RAC), and only 5.7% of RAC+ patients were H. pylori+. The loss of RAC presented 87.2% sensitivity for H. pylori detection, 70.7% specificity, 50% positive predictive value, and 94.3% negative predictive value, indicating that loss of RAC was suboptimal to confirm H. pylori infection, but when RAC was seen, H. pylori infection was unlikely.

CONCLUSION

The presence of RAC at the NF-HD exam and the absence of erythema at S-HD were highly predictive of H. pylori negative status. On the other hand, the loss of RAC had a suboptimal correlation with the presence of H. pylori.

Assessment of Helicobacter pylori status by examination of gastric mucosal patterns: diagnostic accuracy of white-light endoscopy and narrow-band imaging

Objectives

Helicobacter pylori infection is a common cause of chronic gastritis worldwide and an established risk factor for developing gastric malignancy. The endoscopic appearances predicting H. pylori status are an ongoing area of research, as are their diagnostic accuracies. This study aimed to establish the diagnostic accuracy of several mucosal features predictive of H. pylori negative status and formulate a simple prediction model for use at the time of endoscopy.

Design

Patients undergoing high-definition upper gastrointestinal (GI) endoscopy without magnification were recruited prospectively. During the endoscopy, the presence or absence of specific endoscopic findings was noted. Sydney protocol biopsies were used as the diagnostic reference standard, and urease test if taken. The results informed a logistic regression model used to produce a simple diagnostic approach. This model was subsequently validated using a further cohort of 30 patients.

Results

153 patients were recruited and completed the study protocol. The prevalence of active H. pylori infection was 18.3% (28/153). The overall diagnostic accuracy of the simple prediction model was 80.0%, and 100% of patients with active H. pylori infection were correctly classified. The presence of regular arrangement of collecting venules (RAC) showed a positive predictive value for H. pylori naïve status of 90.7%, rising to 93.6% for patients under the age of 60.

Conclusion

A simple endoscopic model may be accurate for predicting H. pylori status of a patient, and the need for biopsy-based tests. The presence of RAC in the stomach is an accurate predictor of H. pylori negative status, particularly in patients under the age of 60.

Trial registration number

The study was registered with ClinicalTrials.gov, No. NCT02385045.

Diagnosis of Helicobacter pylori Infection and Recent Advances

BACKGROUND

Helicobacter pylori (H. pylori) infects approximately 50% of the world population. Its infection is associated with gastropathies, extra-gastric digestive diseases, and diseases of other systems. There is a canonical process from acute-on-chronic inflammation, chronic atrophic gastritis (CAG), intestinal metaplasia (IM), dysplasia, and intraepithelial neoplasia, eventually to gastric cancer (GC). H. pylori eradication abolishes the inflammatory response and early treatment prevents the progression to preneoplastic lesions.

METHODS

the test-and-treat strategy, endoscopy-based strategy, and screen-and-treat strategy are recommended to prevent GC based on risk stratification, prevalence, and patients' clinical manifestations and conditions. Challenges contain false-negative results, increasing antibiotic resistance, decreasing eradication rate, and poor retesting rate. Present diagnosis methods are mainly based on invasive endoscopy and noninvasive laboratory testing.

RESULTS

to improve the accuracy and effectiveness and reduce the missed diagnosis, some advances were achieved including newer imaging techniques (such as image-enhanced endoscopy (IEE), artificial intelligence (AI) technology, and quantitative real-time polymerase chain reaction (qPCR) and digital PCR (dPCR).

CONCLUSION

in the article, we summarized the diagnosis methods of H. pylori infection and recent advances, further finding out the opportunities in challenges.

Gastric foveolar elongation causes invisibility of regular arrangement of collecting venules in chronic active and inactive gastritis

OBJECTIVES

Helicobacter pylori (H pylori) infection is the most common cause of gastritis. The disappearance of regular arrangement of collecting venules (RAC) is well known as one of the main manifestations of H pylori-affected gastritis while the reason behind it remains obscure. The aim of this study was to investigate the relationship between invisibility of RAC and the length of gastric foveolae.

METHODS

43 RAC-positive and 118 RAC-negative patients were enrolled. Gastric biopsy specimens were obtained from lesser and greater curvature of the corpus with RAC-positive or RAC-negative pattern. Histopathological evaluation was performed based on the updated Sydney System, and foveolar length was derived by a morphometric technique.

RESULTS

The median gastric foveolar length in RAC-positive group (median [IQR], 138.54 μm [120.50, 159.09]) was significantly shorter than that in the RAC-negative group (median [IQR], 260.96 μm [217.40, 315.23], P < .05). The length of gastric foveolae in chronic active gastritis (RAC-negative, activity grades 1, 2, and 3) and inactive gastritis (RAC-negative, activity grade 0) was longer than that in normal group (RAC-positive, activity grade 0) (P < .05). The optimal cutoff value for gastric foveolae length of the corpus mucosa showing RAC-negative pattern was more than 181.53 μm. The sensitivity and specificity of more than cutoff value for predicting the invisibility of RAC were 93.03% and 91.78%, respectively.

CONCLUSIONS

The elongation of gastric foveolae caused the invisibility of RAC in gastric corpus mucosa in chronic active and inactive gastritis on gastroendoscopy.

Multispectral imaging detects gastritis consistently in mouse model and in humans

Gastritis constitutes the initial step of the gastric carcinogenesis process. Gastritis diagnosis is based on histological examination of biopsies. Non-invasive real-time methods to detect mucosal inflammation are needed. Tissue optical properties modify reemitted light, i.e. the proportion of light that is emitted by a tissue after stimulation by a light flux. Analysis of light reemitted by gastric tissue could predict the inflammatory state. The aim of our study was to investigate a potential association between reemitted light and gastric tissue inflammation. We used two models and three multispectral analysis methods available on the marketplace. We used a mouse model of Helicobacter pylori infection and included patients undergoing gastric endoscopy. In mice, the reemitted light was measured using a spectrometer and a multispectral camera. We also exposed patient’s gastric mucosa to specific wavelengths and analyzed reemitted light. In both mouse model and humans, modifications of reemitted light were observed around 560 nm, 600 nm and 640 nm, associated with the presence of gastritis lesions. These results pave the way for the development of improved endoscopes in order to detect real-time gastritis without the need of biopsies. This would allow a better prevention of gastric cancer alongside with cost efficient endoscopies.

The endoscopic predictors of Helicobacter pylori status: a meta-analysis of diagnostic performance

Objective:

The endoscopic findings associated with Helicobacter pylori–naïve status, current infection or past infection are an area of ongoing interest. Previous studies have investigated parameters with a potential diagnostic value. The aim of this study was to perform meta-analysis of the available literature to validate the diagnostic accuracy of mucosal features proposed in the Kyoto classification.

Data sources:

The databases of MEDLINE and Embase, clinicalTrials.gov and the Cochrane Library were systematically searched for relevant studies from October 1999 to October 2019.

Methods:

A bivariate random effects model was used to produce pooled diagnostic accuracy calculations for each of the studied endoscopic findings. Diagnostic odds ratios and sensitivity and specificity characteristics were calculated to identify significant predictors of H pylori status.

Results:

Meta-analysis included 4380 patients in 15 studies. The most significant predictor of an H pylori-naïve status was a regular arrangement of collecting venules (diagnostic odds ratio 55.0, sensitivity 78.3%, specificity 93.8%). Predictors of active H pylori infection were mucosal oedema (18.1, 63.7%, 91.1%) and diffuse redness (14.4, 66.5%, 89.0%). Map-like redness had high specificity for previous H pylori eradication (99.0%), but poor specificity (13.0%).

Conclusion:

The regular arrangement of collecting venules, mucosal oedema, diffuse redness and map-like redness are important endoscopic findings for determining H pylori status. This meta-analysis provides a tentative basis for developing future endoscopic classification systems.

Regular arrangement of collecting venules under endoscopy for predicting a Helicobacter pylori-negative stomach: A systematic review and meta-analysis

BACKGROUND AND AIMS

The regular arrangement of collecting venules (RAC) refers to the appearance of multiple regular tiny veins in the body of the stomach and is considered to be very effective for identifying gastric mucosa with non-Helicobacter pylori infection. This meta-analysis was conducted to systematically evaluate the value of the sign in predicting a Helicobacter pylori-negative stomach and the relevant factors that may affect the performance of this prediction.

METHODS

Two biomedical databases (PubMed and EMBASE) were systematically searched through April 20, 2020. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and area under the SROC curve (AUC) were calculated.

RESULTS

Fourteen articles with 4070 patients were included. The pooled sensitivity, specificity, PLR, NLR, DOR and AUC for the RAC in predicting non-Hp infection were 0.80 (0.67-0.89), 0.97 (0.93-0.98), 24.8 (12.2-50.8), 0.21 (0.12-0.36), 120 (47-301) and 0.97 (0.19-1.00), respectively.

CONCLUSIONS

The RAC is a valuable endoscopic feature for the prediction of patients without Hp infection.

Gastric Xanthomas and Fundic Gland Polyps as Endoscopic Risk Indicators of Gastric Cancer

Background/Aims

Fundic gland polyps (FGPs), hyperplastic polyps (HPs), and xanthomas (XTs) are common benign gastric lesions that can be diagnosed by endoscopic appearance alone in most cases. The aim of this study was to evaluate associations between gastric cancer and these benign lesions.

Methods

Two expert endoscopists reviewed a series of gastroscopy images. FGPs, HPs, and XTs were diagnosed by endoscopic appearance, whereas all gastric cancers were confirmed pathologically.

Results

Of the 1,227 patients reviewed, 114 (9.3%) had a concurrent or past history of gastric cancer. The overall prevalences of FGPs, HPs and XTs were 9.4%, 6.3% and 14.2%, respectively. HPs and XTs coexisted in 1.6% of patients, whereas other combinations were rarer. XTs were observed in 39.3% and 11.5% of patients with and without gastric cancer, respectively (p<0.001). In contrast, no gastric cancer patients had FGPs, whereas 10.4% of patients without cancer had FGPs (p<0.001). The prevalence of HPs was similar between the two groups (8.8% and 6.0% of patients with and without cancer, respectively, p=0.29). Multivariate and Mantel-Haenszel analyses demonstrated that XTs were positively associated and FGPs were negatively associated with gastric cancer.

Conclusions

XTs and FGPs might be useful as endoscopic risk indicators for monitoring gastric cancer.

Differential diagnosis of Helicobacter pylori-associated gastritis with the linked-color imaging score

BACKGROUND

Helicobacter pylori (H. pylori) infection in gastric mucosa is the main risk factor for gastric cancer. The purpose of this study was to assess the value of the linked-color imaging (LCI) score for the identification of H. pylori-associated gastritis.

METHODS

A total of 358 patients were enrolled in the study. H. pylori was positive in 127 cases and negative in 231 cases. Redness of fundus glands, granular erosion, purple mucus (+) and mucus lake turbidity were investigated by the LCI mode of endoscopy. Logistic regression was used to screen the observation indexes and their relative partial regression coefficients, which were helpful for the differential diagnosis of H. pylori infection. Then, each observation index was scored according to the partial regression coefficient.

RESULTS

Using a total scores of 3.5 as the cut-off value, the sensitivity and specificity were 83.8% and 99.5%, respectively, for the differential diagnosis of H. pylori gastritis. The area under the curve was 95.3%.

CONCLUSIONS

The LCI score showed high sensitivity and specificity for the differential diagnosis of H. pylori-associated gastritis and is an effective method for identifying H. pylori infection in gastric mucosa.

High Accuracy of Convolutional Neural Network for Evaluation of Helicobacter pylori Infection Based on Endoscopic Images: Preliminary Experience

OBJECTIVES

Application of artificial intelligence in gastrointestinal endoscopy is increasing. The aim of the study was to examine the accuracy of convolutional neural network (CNN) using endoscopic images for evaluating Helicobacter pylori (H. pylori) infection.

METHODS

Patients who received upper endoscopy and gastric biopsies at Sir Run Run Shaw Hospital (January 2015-June 2015) were retrospectively searched. A novel Computer-Aided Decision Support System that incorporates CNN model (ResNet-50) based on endoscopic gastric images was developed to evaluate for H. pylori infection. Diagnostic accuracy was evaluated in an independent validation cohort. H. pylori infection was defined by the presence of H. pylori on immunohistochemistry testing on gastric biopsies and/or a positive 13C-urea breath test.

RESULTS

Of 1,959 patients, 1,507 (77%) including 847 (56%) with H. pylori infection (11,729 gastric images) were assigned to the derivation cohort, and 452 (23%) including 310 (69%) with H. pylori infection (3,755 images) were assigned to the validation cohort. The area under the curve for a single gastric image was 0.93 (95% confidence interval [CI] 0.92-0.94) with sensitivity, specificity, and accuracy of 81.4% (95% CI 79.8%-82.9%), 90.1% (95% CI 88.4%-91.7%), and 84.5% (95% CI 83.3%-85.7%), respectively, using an optimal cutoff value of 0.3. Area under the curve for multiple gastric images (8.3 ± 3.3) per patient was 0.97 (95% CI 0.96-0.99) with sensitivity, specificity, and accuracy of 91.6% (95% CI 88.0%-94.4%), 98.6% (95% CI 95.0%-99.8%), and 93.8% (95% CI 91.2%-95.8%), respectively, using an optimal cutoff value of 0.4.

DISCUSSION

In this pilot study, CNN using multiple archived gastric images achieved high diagnostic accuracy for the evaluation of H. pylori infection.

High-resolution magnified endoscopy combined with flexible spectral imagining colour enhancement techniques in the diagnosis of Helicobacter pylori disease

Aim

To evaluate the efficiency of the flexible spectral imaging colour enhancement (FICE) procedure added to high-resolution magnified endoscopy (HRME) for the evaluation of structural changes in gastric mucosa infected with Helicobacter pylori (H. pylori).

Material and methods

A total of 104 patients were included in the study. First HRME and then HRME + FICE methods were used for the evaluation of the gastric mucosal structure, and examined areas were studied histopathologically. Mucosal appearance was evaluated with the modified Yagi classification. Images were shown to five endoscopists in order to examine inter- and intra-observer variability in image assessment.

Results

Sensitivity and specificity of the image pattern noted with HRME in the antrum in the detection of H. pylori were 67.9% and 84.6%, respectively, while these were 93.5% and 92.3%, respectively, with HRME + FICE. Type 5 pattern in the antrum, which we thought to be associated with intestinal metaplasia, was not observed in any patient with HRME. Sensitivity and specificity values of type 5 pattern noted with HRME + FICE technique for intestinal metaplasia were 50% and 98.8%, respectively.

Conclusions

The results show that HRME + FICE as a digital chromoendoscopic method provided an additional diagnostic contribution to HRME for showing the presence of H. pylori and intestinal metaplasia and is a method with higher sensitivity and specificity. The “patchy appearance” (type 5) observed in the antrum not previously described in the evaluations with FICE can be a guiding sign especially for the diagnosis of intestinal metaplasia.

Association between a regular arrangement of collecting venules and absence of Helicobacter pylori infection in a European population

BACKGROUND AND AIMS

Helicobacter pylori is the major cause of gastritis and gastritis-associated diseases. Detection of a regular arrangement of collecting venules (RAC) in the lesser gastric curvature correlates with negative H pylori status with a sensitivity and negative predictive value (NPV) higher than 90% in Asian countries. The aim of the study was to evaluate the value of RAC as a diagnostic method of H pylori infection in a European population.

METHODS

A prospective study with high-definition endoscopes without magnification was performed by 3 endoscopists. The presence of starfish-like minute points regularly distributed throughout the lesser curvature of the gastric body was considered RAC positive (RAC+). Gastric biopsies were performed during the procedure for H pylori diagnosis.

RESULTS

One hundred forty patients were included from February 2017 to May 2018. The prevalence of H pylori infection was 31% and 47 of 140 patients (34%) were RAC+; 13 of 23 patients in whom H pylori was eradicated were RAC+. The mean age of RAC+ patients was lower (44.4 vs 52.4 years, P = .004) and they had less- significant endoscopic findings (9; 19.1% vs 38; 80.9%; P = .017). Gender, use of nonsteroidal anti-inflammatory drugs, antithrombotic or anticoagulants treatments, and a history of H pylori eradication did not show differences in the RAC pattern. The absence of RAC was associated with H pylori infection in 47.3% (44/93) of cases. In contrast, all RAC+ patients were free of H pylori infection, with sensitivity and NPV of 100% for the exclusion of H pylori infection.

CONCLUSION

The presence of RAC+ in the lesser curvature evaluated with high-definition endoscopy can accurately identify patients without H pylori.

British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma

Gastric adenocarcinoma carries a poor prognosis, in part due to the late stage of diagnosis. Risk factors include Helicobacter pylori infection, family history of gastric cancer-in particular, hereditary diffuse gastric cancer and pernicious anaemia. The stages in the progression to cancer include chronic gastritis, gastric atrophy (GA), gastric intestinal metaplasia (GIM) and dysplasia. The key to early detection of cancer and improved survival is to non-invasively identify those at risk before endoscopy. However, although biomarkers may help in the detection of patients with chronic atrophic gastritis, there is insufficient evidence to support their use for population screening. High-quality endoscopy with full mucosal visualisation is an important part of improving early detection. Image-enhanced endoscopy combined with biopsy sampling for histopathology is the best approach to detect and accurately risk-stratify GA and GIM. Biopsies following the Sydney protocol from the antrum, incisura, lesser and greater curvature allow both diagnostic confirmation and risk stratification for progression to cancer. Ideally biopsies should be directed to areas of GA or GIM visualised by high-quality endoscopy. There is insufficient evidence to support screening in a low-risk population (undergoing routine diagnostic oesophagogastroduodenoscopy) such as the UK, but endoscopic surveillance every 3 years should be offered to patients with extensive GA or GIM. Endoscopic mucosal resection or endoscopic submucosal dissection of visible gastric dysplasia and early cancer has been shown to be efficacious with a high success rate and low rate of recurrence, providing that specific quality criteria are met.

Narrow band imaging and serology in the assessment of premalignant gastric pathology

BACKGROUND

Patient outcomes in gastric adenocarcinoma are poor due to late diagnosis. Detecting and treating at the premalignant stage has the potential to improve this. Helicobacter pylori is also a strong risk factor for this disease.

AIMS

Primary aims were to assess the diagnostic accuracy of magnified narrow band imaging (NBI-Z) endoscopy and serology in detecting normal mucosa, H. pylori gastritis and gastric atrophy. Secondary aims were to compare the diagnostic accuracies of two classification systems using both NBI-Z and white light endoscopy with magnification (WLE-Z) and evaluate the inter-observer agreement.

METHODS

Patients were prospectively recruited. Images of gastric mucosa were stored with histology and serum for IgG H. pylori and Pepsinogen (PG) I/II ELISAs. Blinded expert endoscopists agreed on mucosal pattern. Mucosal images and serological markers were compared with histology. Kappa statistics determined inter-observer variability for randomly allocated images among four experts and four non-experts.

RESULTS

116 patients were prospectively recruited. Diagnostic accuracy of NBI-Z for determining normal gastric mucosa was 0.87(95%CI 0.82-0.92), H. pylori gastritis 0.65(95%CI 0.55-0.75) and gastric atrophy 0.88(95%CI 0.81-0.94). NBI-Z was superior to serology at detecting gastric atrophy: NBI-Z gastric atrophy 0.88(95%CI 0.81-0.94) vs PGI/II ratio < 3 0.74(95%CI 0.62-0.85) p<.0001. Overall NBI-Z was superior to WLE-Z in detecting disease using two validated classifications. Inter-observer agreement was 0.63(95%CI 0.51-0.73).

CONCLUSIONS

NBI-Z accurately detects changes in the GI mucosa which currently depend on histology. NBI-Z is useful in the detection of precancerous conditions, potentially improving patient outcomes with early intervention to prevent gastric cancer.

The effect of vitamin D deficiency on eradication rates of Helicobacter pylori infection

Background/Aim

Many studies have investigated risk factors other than antibiotic resistance linked to Helicobacter pylori (H. pylori) eradication failure. The aim of this study was to study the effect of serum levels of 25‐hydroxy‐vitamin D (25[OH]D) on eradication rates of H. pylori infection.

Methods

This study included 150 patients diagnosed with H. pylori gastritis using magnifying narrow‐band imaging endoscopy supported by stool antigen test. Serum 25‐OH vitamin D levels were measured via the Enzyme‐Linked Immune Sorbent assay (ELISA) method before starting eradication therapy of H. pylori infection. All patients were treated with clarithromycin‐based triple therapy for 14 days. H. pylori eradication was determined via a stool antigen test performed 4 weeks after the end of therapy. According to the serum level of 25‐OH vitamin D levels, the patients were divided into two groups: group I (sufficient) had a vitamin D level of ≥20 ng/mL, while group II (deficient) had a vitamin D level of <20 ng/mL.

Results

Our results revealed that eradication was successful in 105 (70%) patients and failed in 45 (30%) patients. The mean 25[OH]D level was significantly lower in the eradication failure group compared to the successful treatment group (14.7 ± 4.5 vs 27.41 ± 7.1; P < 0.001). Furthermore, there were significantly more patients with deficient 25[OH]D levels in the failed treatment group, 30 (66.6%), compared to the successful group, 10 (9.5%) (P < 0.001).

Conclusions

Our results demonstrated that 25‐OH vitamin D deficiency may be considered a risk factor related to eradication failure of H. pylori infection. In addition, a further randomized trial to evaluate the effect of vitamin D supplementation in H. pylori eradication is mandatory.

Diagnostic Performance of Magnifying Endoscopy for Helicobacter pylori Infection: A Meta-Analysis

Background

Diagnosis of Helicobacter pylori (H. pylori) infection using magnifying endoscopy offers advantages over conventional invasive and noninvasive tests.

Objective

This meta-analysis aimed to assess the diagnostic performance of magnifying endoscopy in the prediction of H. pylori infection.

Methods

A literature search of the PubMed, Medline, EMBASE, Science Direct and the Cochrane Library databases was performed. A random-effects model was used to calculate the diagnostic efficiency of magnifying endoscopy for H. pylori infection. A summary receiver operator characteristic curve was plotted, and the area under the curve (AUC) was calculated.

Results

A total of 18 studies involving 1897 patients were included. The pooled sensitivity and specificity of magnifying endoscopy to predict H. pylori infection were 0.89 [95% confidence interval (CI) 0.87–0.91] and 0.82 (95%CI 0.79–0.85), respectively, with an AUC of 0.9461. When targeting the gastric antrum, the pooled sensitivity and specificity were 0.82 (95%CI 0.78–0.86) and 0.72 (95%CI 0.66–0.78), respectively. When targeting the gastric corpus, the pooled sensitivity and specificity were 0.92 (95%CI 0.90–0.94) and 0.86 (95%CI 0.82–0.88), respectively. The pooled sensitivity and specificity using magnifying white light endoscopy were 0.90 (95%CI 0.87–0.91) and 0.81 (95%CI 0.77–0.84), respectively. The pooled sensitivity and specificity using magnifying chromoendoscopy were 0.87 (95%CI 0.83–0.91) and 0.85 (95%CI 0.80–0.88), respectively. The “pit plus vascular pattern” classification in the gastric corpus observed by magnifying endoscopy was able to accurately predict the status of H. pylori infection, as indicated by a pooled sensitivity and specificity of 0.96 (95%CI 0.94–0.97) and 0.91 (95%CI 0.87–0.93), respectively, with an AUC of 0.9872.

Conclusions

Magnifying endoscopy was able to accurately predict the status of H. pylori infection, either in magnifying white light endoscopy or magnifying chromoendoscopy mode. The “pit plus vascular pattern” classification in the gastric corpus is an optimum diagnostic criterion.

Evidence based review of the impact of image enhanced endoscopy in the diagnosis of gastric disorders

Gastric cancer is the third most common cause of cancer-related death. Advanced stages of gastric cancers generally have grim prognosis. But, good prognosis can be achieved if such cancers are detected, diagnosed and resected at early stages. However, early gastric cancers and its precursors often produce only subtle mucosal changes and therefore quite commonly remain elusive at the conventional examination with white light endoscopy. Image-enhanced endoscopy makes mucosal lesions more conspicuous and can therefore potentially yield earlier and more accurate diagnoses. Recent years have seen growing work of research in support of various types of image enhanced endoscopy (IEE) techniques (e.g., dye-chromoendoscopy; magnification endoscopy; narrow-band imaging; flexible spectral imaging color enhancement; and I-SCAN) for a variety of gastric pathologies. In this review, we will examine the evidence for the utilization of various IEE techniques in the diagnosis of gastric disorders.

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

CONVENTIONAL VIDEOENDOSCOPY CAN IDENTIFY HELICOBACTER PYLORI GASTRITIS?

BACKGROUND

Studies with latest technologies such as endoscopy with magnification and chromoendoscopy showed that various endoscopic aspects are clearly related to infection by Helicobacter pylori (HP). The description of different patterns of erythema in gastric body under magnification of images revived interest in identifying these patterns by standard endoscopy.

AIM

To validate the morphologic features of gastric mucosa related to H. pylori infection gastritis allowing predictability of their diagnosis as well as proper targeting biopsies.

METHODS

Prospective study of 339 consecutive patients with the standard videoendoscope image analysis were obtained, recorded and stored in a program database. These images were studied with respect to the presence or absence of H. pylori, diagnosed by rapid urease test and/or by histological analysis. Were studied: a) normal mucosa appearance; b) mucosal nodularity; c) diffuse nonspecific erythema or redness (with or without edema of folds and exudate) of antrum and body; d) mosaic pattern with focal area of hyperemia; e) erythema in streaks or bands (red streak); f) elevated (raised) erosion; g) flat erosions; h) fundic gland polyps. The main exclusion criteria were the use of drugs, HP pre-treatment and other entities that could affect results.

RESULTS

Applying the exclusion criteria, were included 170 of the 339 patients, of which 52 (30.58%) were positive for HP and 118 negative. On the positive findings, the most associated with infection were: nodularity in the antrum (26.92%); presence of raised erosion (15.38%) and mosaic mucosa in the body (21.15%). On the negative group the normal appearance of the mucosa was 66.94%; erythema in streaks or bands in 9.32%; flat erosions 11.86%; and fundic gland polyps 11.86%.

CONCLUSION

Endoscopic findings are useful in the predictability of the result and in directing biopsies. The most representative form of HP related gastritis was the nodularity of the antral mucosa. The raised erosion and mucosa in mosaic in the body are suggestive but not specific to the infection. The other forms were not conclusive of the presence of HP.

Application of endoscopic molecular imaging in diagnosis of gastric intestinal metaplasia

Gastric intestinal metaplasia (GIM) is a precancerous lesion of intestinal type gastric carcinoma. Early diagnosis and follow-up can improve the detection rate of early gastric cancer. In recent years, with the integration of molecular imaging into endoscopy, auto fluorescence endoscopy, Raman spectroscopy, two-photon fluorescence endomicroscopy, and confocal laser endomicroscopy have emerged, which improves the detection rate of GIM. This paper reviews the progress of the application of endoscopic molecular imaging in the diagnosis of GIM.

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Kyoto global consensus report on Helicobacter pylori gastritis

OBJECTIVE

To present results of the Kyoto Global Consensus Meeting, which was convened to develop global consensus on (1) classification of chronic gastritis and duodenitis, (2) clinical distinction of dyspepsia caused by Helicobacter pylori from functional dyspepsia, (3) appropriate diagnostic assessment of gastritis and (4) when, whom and how to treat H. pylori gastritis.

DESIGN

Twenty-three clinical questions addressing the above-mentioned four domains were drafted for which expert panels were asked to formulate relevant statements. A Delphi method using an anonymous electronic system was adopted to develop the consensus, the level of which was predefined as ≥80%. Final modifications of clinical questions and consensus were achieved at the face-to-face meeting in Kyoto.

RESULTS

All 24 statements for 22 clinical questions after extensive modifications and omission of one clinical question were achieved with a consensus level of >80%. To better organise classification of gastritis and duodenitis based on aetiology, a new classification of gastritis and duodenitis is recommended for the 11th international classification. A new category of H. pylori-associated dyspepsia together with a diagnostic algorithm was proposed. The adoption of grading systems for gastric cancer risk stratification, and modern image-enhancing endoscopy for the diagnosis of gastritis, were recommended. Treatment to eradicate H. pylori infection before preneoplastic changes develop, if feasible, was recommended to minimise the risk of more serious complications of the infection.

CONCLUSIONS

A global consensus for gastritis was developed for the first time, which will be the basis for an international classification system and for further research on the subject.

Gastric Cancer Risk in Patients with Helicobacter pylori Infection and Following Its Eradication

As Helicobacter pylori is a first-class carcinogen, eradication of the infection would be expected to be a beneficial measure for the (primary) prevention of gastric cancer. Given the natural history of gastric cancer, it is plausible that eradication before gastric atrophy sets in offers the best chance for cancer risk reduction. The beneficial effects of eradication may, nevertheless, still be achievable in more advanced disease. The reversibility of inflammatory lesions has been supported by undeniable evidence; the regression of mucosal atrophy/metaplasia has also been confirmed by several recent histologic studies.

Review of atrophic gastritis and intestinal metaplasia as a premalignant lesion of gastric cancer

Atrophic gastritis (AG) and intestinal metaplasia (IM) are the main precursor lesions of gastric cancer as the incidence of gastric cancer increases in the gastric mucosa involved with AG and IM. The prevalence of AG and IM vary depending on countries, even it represents diverse results in the same nation. Usually AG is antecedent of IM but the etiologies of AG and IM are not always the same. The sensitivity and specificity of diagnostic methods to detect AG and IM are different. Furthermore, the management strategy of AG and IM has not been established, yet. Helicobacter pylori infection has been proved as the most important cause of AG and IM. Thus the eradication of H. pylori is very important to prevent the progression to gastric cancer which is still placed in the high rank in morbidity and mortality among cancers. However, the reversibility of AG and IM by eradication of H. pylori which was assumed to be certain by meta-analysis is; however, controversial now. Therefore, the understanding and early diagnosis of AG and IM are very important, especially, in high incidence area of gastric cancer such as Republic of Korea.

Endoscopic features of lymphoid follicles in Helicobacter pylori-associated chronic gastritis

BACKGROUND AND AIM

Small, round, yellowish-white nodules (YWN) are frequently observed in Helicobacter pylori-associated gastritis. The aim of the present study was to investigate the clinical significance of these YWN.

METHODS

Participants comprised 211 patients with H. pylori-associated gastritis, ranging in age from 23 to 86 years.

RESULTS

YWN were detected in 23% of participants, more frequently in women (33%) than in men (12%; P < 0.01). YWN were observed on the antral mucosa in 4.7% of cases, lesser curvature of the corpus mucosa in 20%, greater curvature of the corpus mucosa in 0.9%, and fundic mucosa in 12%. Most YWN located on the antral mucosa showed nodular type, and most YWN located on the corpus mucosa and fundic mucosa showed flat type. On magnifying endoscopy with narrow-band imaging, YWN appeared as round whitish lesions with radial or branching microvessels on the surface and hypovascular globe structures just beneath the surface of the mucosa. Targeted biopsies of YWN revealed lymphoid follicles with lymphocyte infiltration or intense inflammatory cell infiltration.

CONCLUSION

The endoscopic finding of YWN could be observed at any site of the gastric mucosa in H. pylori-associated gastritis, and represented histological lymphoid follicles.

Diagnosing Helicobacter pylori infection in vivo by novel endoscopic techniques

Infection with Helicobacter pylori (H. pylori) is a worldwide problem. Endoscopic observation of H. pylori infection in vivo would be helpful to obtain an immediate diagnosis. The aim of this review is to describe recent advances in endoscopic technology and to review the available literature pertaining to its clinical application in H. pylori infection. Endoscopic visualization of H. pylori infection is not always feasible using conventional endoscopy. Thus, advanced endoscopic techniques have been developed with the aim of providing a precise and ‘‘real-time’’ endoscopic diagnosis. Recently, new endoscopic techniques such as magnifying endoscopy, narrow band imaging, I-Scan, endocytoscopy and endomicroscopy help focus examination of the stomach to diagnose disease in a time-efficient manner, and the analysis of mucosal surface details is beginning to resemble histologic examination. The new detailed images have enabled endoscopists to observe microscopic structures, such as gastric pit patterns, microvessels and cell morphology. Accordingly, endoscopic prediction of H. pylori infection is possible by analysis of surface architecture of the mucosa, which influences the clinical management. These endoscopic techniques might lead us to easier diagnosis and treatment of H. pylori-related diseases.

Helicobacter pylori infection - recent developments in diagnosis

Considering the recommended indications for Helicobacter pylori (H. pylori) eradication therapy and the broad spectrum of available diagnostic methods, a reliable diagnosis is mandatory both before and after eradication therapy. Only highly accurate tests should be used in clinical practice, and the sensitivity and specificity of an adequate test should exceed 90%. The choice of tests should take into account clinical circumstances, the likelihood ratio of positive and negative tests, the cost-effectiveness of the testing strategy and the availability of the tests. This review concerns some of the most recent developments in diagnostic methods of H. pylori infection, namely the contribution of novel endoscopic evaluation methodologies for the diagnosis of H. pylori infection, such as magnifying endoscopy techniques and chromoendoscopy. In addition, the diagnostic contribution of histology and the urea breath test was explored recently in specific clinical settings and patient groups. Recent studies recommend enhancing the number of biopsy fragments for the rapid urease test. Bacterial culture from the gastric biopsy is the gold standard technique, and is recommended for antibiotic susceptibility test. Serology is used for initial screening and the stool antigen test is particularly used when the urea breath test is not available, while molecular methods have gained attention mostly for detecting antibiotic resistance.

Diagnostic capabilities of high-definition white light endoscopy for the diagnosis of gastric intestinal metaplasia and correlation with histologic and clinical data

OBJECTIVE

The aim of this study was the evaluation of the diagnostic accuracy of a specific high-definition white light endoscopy (HD-WLE) system for the optical recognition of intestinal metaplasia (IM) and the assessment of its correlation with histologic and clinical data.

METHODS

A total of 234 patients undergoing upper gastrointestinal endoscopy in an outpatient endoscopy suite for various indications were prospectively enrolled in this cross-sectional study. Gastric IM was diagnosed on the basis of three mucosal patterns identified using HD-WLE in a per-patient analysis. Histological evaluation was used as the gold standard, and special staining was conducted for subtyping of IM. Main outcome measurements were sensitivity, specificity, and likelihood ratio of HD-WLE and secondary associations with histologic and clinical data.

RESULTS

IM was found in 63/234 (27%) patients and low-grade dysplasia in 6/63 patients (9.5%). Sensitivity, specificity, accuracy, and likelihood ratio of all mucosal patterns were 74.6, 94, 88% and 13, respectively. All clinically significant type III IM and dysplasia lesions were endoscopically detected. All nonvisible lesions were of types I and II with mild grade and no dysplasia. Ten patients were considered false positives and the lesions were associated with severe inflammation and antralization.

CONCLUSION

The specific HD-WLE system showed satisfactory accuracy and high specificity during real-time, routine endoscopy practice. Specific mucosal patterns were correlated with level and grade of lesions. The sensitivity of the system is even higher when only clinically significant IM lesions are considered.

Diagnosis of Helicobacter pylori infection in gastric mucosa by endoscopic features: a multicenter prospective study

BACKGROUND

Endoscopic features corresponding to pathological findings in the Sydney System have not been identified, and endoscopic diagnosis of chronic gastritis has not yet been established. To establish the diagnosis of Helicobacter pylori (H. pylori) infection in gastric mucosa by endoscopic features, a prospective multicenter study was carried out.

PATIENTS AND METHODS

Two hundred and ninety-seven registered patients from 24 facilities between March 2008 and February 2009 were enrolled. Association between endoscopic findings (conventional findings and indigocarmine contrast (IC) method findings) and diagnosis of H. pylori infection made by microscopic observation of biopsy specimens was investigated in the corpus and antrum and their diagnostic accuracies were investigated.

RESULTS

Two hundred and seventy-five patients were analyzed. The area under the receiver operating characteristic (ROC) curve for H. pylori infection of conventional endoscopy was 0.811 in thecorpus and 0.707 in the antrum (P = 0.006). Evaluation of diffuse redness, spotty redness and mucosal swelling by conventional endoscopy and swelling of areae gastricae by the indigocarmine contrast (IC) method were useful for diagnosing H. pylori infection. Regular arrangement of collecting venules (RAC) in the angle, fundic gland polyposis, hemorrhagic erosion and bleeding spot in the corpus and red streaks, and erosions (flat, raised, hemorrhagic and bleeding spot) in the antrum may be used as diagnostic features suggesting negative H. pylori infection.

CONCLUSION

It is suggested that endoscopic diagnosis of H. pylori infection in gastric mucosa by conventional endoscopy and the IC method is mostly possible.

Irregular arrangement of collecting venules (IRAC) provides a critical endoscopic insight in Helicobacter pylori-induced gastritis: A secondary publication

The aim of this study was to evaluate the significance of an endoscopic atrophic border and irregular arrangement of collecting venules (IRAC) in the diagnosis of Helicobacter pylori (H. pylori)-induced gastritis. Upper gastrointestinal tract endoscopy was performed on 723 patients, who were screened them for H. pylori infection. Any patients who had undergone H. pylori eradication therapy were excluded from the study. The endoscopic atrophic border and IRAC in each patient were assessed. The H. pylori status was determined in the patients by combination of a serological test and/or histopathological examination. The H. pylori infection rates were 95.4% (455/477) in the group with an endoscopic atrophic border and 22.3% (55/246) in the group without an endoscopic atrophic border. In the diagnostic validity check, presence of an endoscopic atrophic border had a sensitivity of 89.2% and a specificity of 89.7%. Furthermore, the H. pylori infection rates were 95.5% (506/530) in the IRAC group and 2.1% (4/193) in the regular arrangement of collecting venules (RAC) group. In the diagnostic validity check, IRAC had a sensitivity of 99.2% and a specificity of 88.7%. In conclusion, the presence of an endoscopic atrophic border and IRAC are highly indicative of an H. pylori-infected gastric mucosa.

Emerging technologies in endoscopic imaging

Endoscopic imaging is in part responsible for the recent drop in deaths from gastrointestinal cancers and also for detecting pre-cancerous and non-cancerous conditions and allowing them to be treated effectively, although techniques are far from perfect. Endoscopic imaging has evolved considerably from fiber optic systems 50 years ago to high resolution and high definition systems used at present. Moreover, image enhancement using filters and processors has led to the technique of 'electronic chromoendoscopy' to visualize mucosal blood vessels and surface pit patterns clearly. Magnification by optical zoom or confocal laser microscopy has enabled real time diagnosis and 'virtual histology'. These techniques have contributed to the early detection, assessment and treatment of various gastrointestinal pathologies. The focus of future research is directed towards molecular targeted imaging.

Correlation between the endoscopic and histologic diagnosis of gastritis

Our aims were to determine the rate of concordance between endoscopic and pathologic diagnoses of gastritis and to determine if there was any common factor in discordant cases. A retrospective analysis of data from 400 patients was performed. The endoscopic diagnoses were compared with the pathologic diagnoses, and histologic slides from discordant cases were reviewed. Of the 400 patients, there was discordance between endoscopy and histology in 136 (34%; κ statistic, 0.31). These discordant cases comprised 56 with normal endoscopy but abnormal histology and 80 with abnormal endoscopy but normal histology. In 13 patients, there was normal histology, although erosions had been diagnosed endoscopically. No consistent histologic features were found in the discordant cases. These findings show that standard endoscopy is a poor predictor of pathologic changes. Biopsies are required for accurate diagnosis of gastritis.

Regular arrangement of collecting venules: Does patient age affect its accuracy?

AIM

To address the diagnostic value of the regular arrangement of collecting venules (RAC) among old age patients.

METHODS

A total of 390 consecutive patients whose Helicobacter pylori (H. pylori) status was known and who received upper gastrointestinal endoscopy, were retrospectively studied for the presence or absence of RAC as well as gastric mucosal atrophy. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of RAC to detect normal gastric mucosa were assessed and were compared among two different age groups of patients.

RESULTS

The mean age ± standard deviation (SD) of included patients (n = 390), was 62.9 ± 13 years. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of RAC to detect normal gastric mucosa were 91.7%, 66.1%, 18.8%, 99% and 68.1% respectively. Although the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of RAC among patients < 60 years (n = 139) was 94.7%, 71.2%, 46.2%, 98.1%and 76.1%, respectively, it was 80%, 64.3%, 5.1%, 93% and 64.6%, respectively, among patients ≥ 60 years (n = 251). Younger Patients (< 60 years), have highly significant rates of RAC sensitivity, positive predictive value, and accuracy (P ≤ 0.001, ≤ 0.001 and ≤ 0.02, respectively). Older patients had highly significant rates of H. pylori infection and gastric mucosal atrophy (P ≤ 0.01).

CONCLUSION

Although RAC is a valuable sign for real-time identification of normal gastric mucosa, its accuracy seems to be affected by the patient's age.

Enhanced mucosal imaging

PURPOSE OF REVIEW

The continued application of innovative imaging systems to endoscopic procedures has vastly improved the detection of indiscriminant tissue anomalies. This article describes the fundamental principles of these technologies and reviews the advances of each over the past 18 months, considering their utility in the diagnosis and surveillance of various gastrointestinal diseases.

RECENT FINDINGS

Through a combination of novel optics, processors and filters, real-time high-resolution contrast endoscopy provides increased visual data without greater procedure duration or difficulty. Optical contrast techniques incorporated into endoscopes, such as narrow band imaging (Olympus), i-Scan (Pentax), and Fujinon Intelligent Chromo Endoscopy, have become standard of care for many endoscopists. These technologies, as well as autofluorescence imaging, potentially improve detection of mucosal abnormalities, serving as 'red flag' tools for the evaluation of wide areas of mucosa. In addition, a number of promising devices allow virtual histology and in-vivo diagnosis, thereby directing biopsies and potentially guiding concurrent interventions. One such technology, confocal laser endomicroscopy, continues to establish its role in clinical practice. Because of inherent shortcomings affecting each modality's sensitivity and specificity, the coupling of various devices, as with endoscopic trimodal imaging, has shown great promise; however, most are not widely available and not definitively proven to be superior to more established techniques. Emerging technologies, including in-vivo molecular tagging, provide a powerful means of detecting disease without reliance on morphologic diagnostic criteria.

SUMMARY

Endoscopy continues to evolve from a field that previously allowed only macroscopic imaging dependent on subsequent pathology to one that allows real-time in-vivo diagnosis. Although the promise of enhanced endoscopic technologies seems limitless, practical and technological considerations slow their adoption into the standard of care.

Near-infrared Raman spectroscopy for optical diagnosis in the stomach: identification of Helicobacter-pylori infection and intestinal metaplasia

Raman spectroscopy is a unique vibrational spectroscopic technique which can be used to probe biochemicals and biomolecular structures and conformations of tissues. The main objective of this study is to evaluate the feasibility of applying near-infrared (NIR) Raman spectroscopy for identification of nonneoplastic lesions (Helicobacter-pylori (Hp) infection, and intestinal metaplasia (IM)) highly associated with stomach cancer. A rapid-acquisition NIR Raman spectroscopic system was used for tissue Raman measurements at 785 nm excitation, and a total of 88 gastric tissue samples (57 normal; 11 Hp-infection; 20 IM) from 56 patients were measured. The principal components analysis (PCA) and linear discriminant analysis (LDA) techniques were implemented to develop effective diagnostic algorithms for classification of Raman spectra of different gastric tissue types. High-quality Raman spectra in the range of 800-1800 cm(-1) were acquired from gastric tissue within 5 seconds. Significant spectral differences in Raman spectra were observed among normal, Hp-infection and IM gastric tissue, particularly in the spectral ranges of 848-917, 960-1015, 1088-1133, 1206-1213, 1277-1313, 1395-1445, 1517-1549, 1607-1690, and 1714-1767 cm(-1) which contained signals related to proteins, lipids and porphyrin. PCA-LDA algorithms developed together with leave one patient out, cross validation technique yield diagnostic sensitivities of 91.7%, 80.0%, and 80.0%, and specificities of 80.0%, 100%, and 92.7%, respectively, for classification of normal, Hp-infection and IM gastric tissues. This work demonstrates the utility of NIR Raman spectroscopy for early diagnosis of Hp-infection and IM lesions in the gastric at the molecular level.

Diagnosis of Helicobacter pylori infection

The articles published this last year in the field of Helicobacter pylori diagnosis reported the development of in vivo histology, small improvements in some invasive methods (urease test, culture, and histology) and new kits for the stool antigen tests. They also contributed to increasing our knowledge, by further exploration into specific conditions for the urea breath test and into the significance of cagA antibodies. The role of serum markers of atrophy was also confirmed. Molecular methods are still being developed for direct genotyping, detection of H. pylori and its clarithromycin resistance, either by polymerase chain reaction or fluorescent in-situ hybridization. For the first time, there was a report on a possible interest of magnetic resonance spectroscopy.