Meta-analysis: narrow band imaging for lesion characterization in the colon, oesophagus, duodenal ampulla and lung

Treatment experience with and clinicopathological analysis of vocal fold leukoplakia per appearance classification guidance: a cohort of 1442 patients

OBJECTIVE

To analyse the comparative clinical outcomes and clinicopathological significance of vocal fold leukoplakia lesions treated by appearance classification and traditional methods.

METHOD

A total of 1442 vocal fold leukoplakia patients were enrolled. Group A patients were treated according to appearance classification and Group B patients were treated according to traditional methods.

RESULTS

In Group A, 24.4, 14.9 and 60.6 per cent of patients had grade I, II and III dysplasia, respectively. Grade I dysplasia (63.4 per cent) was more than twice as frequent in Group B patients than in Group A patients, while grade II dysplasia (20.4 per cent) and grade III dysplasia (16.2 per cent) were significantly less frequent in Group B patients than in Group A patients (p = 0.000). There was a significant correlation between vocal fold leukoplakia appearance and the degree of dysplasia (p = 0.000). The recurrence and malignant transformation rates (17.6 and 31 per cent, respectively) in Group B were significantly greater than those in Group A (10.8 and 25.9 per cent, respectively) (p = 0.000).

CONCLUSION

Vocal fold leukoplakia appearance classification is useful for guiding treatment decision-making and could help to improve therapeutic accuracy.

Case Reports: Bronchial Mucosal Vasculature Is Also Involved in the Acute Vascular Distress Syndrome of COVID-19

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which targets the pulmonary vasculature is supposed to induce an intrapulmonary right to left shunt with an increased pulmonary blood flow. We report here what may be, to the best of our knowledge, the first videoendoscopic descriptions of an hypervascularization of the bronchial mucosa in two patients hospitalized for coronavirus disease 2019 (COVID-19) pneumonia.

Cases Presentation: Two patients, 27- and 37-year-old, were addressed to our Pneumology department for suspicion of COVID-19 pneumonia. Their symptoms (fever, dry cough, and dyspnoea), associated to pulmonary ground glass opacities on thoracic CT, were highly suggestive of a COVID-19 disease despite repeated negative pharyngeal swabs RT-PCR. In both patients, bronchoscopy examination using white light was unremarkable but NBI bronchoscopy revealed a diffuse hypervascularization of the mucosa from the trachea to the sub-segmental bronchi, associated with dilated submucosal vessels. RT-PCR performed in bronchoalveolar lavage (BAL) confirmed the presence of Sars-CoV-2.

Conclusions: These two case reports highlight the crucial importance of the vascular component of the viral disease. We suggest that such bronchial hypervascularization with dilated vessels contributes, at least in part, to the intrapulmonary right to left shunt that characterizes the COVID-19 related Acute Vascular Distress Syndrome (AVDS). The presence of diffuse bronchial hypervascularization in the context of COVID-19 pandemic should prompt the search for Sars-CoV-2 in BAL samples.

Contribution of narrow band imaging in delineation of laryngopharyngeal superficial cancer spread: a prospective study

PURPOSE

The aim of this study was to assess the performance of Narrow Band Imaging (NBI) added to White Light (WL) in the delineation of laryngopharyngeal superficial cancer spread during office-based transnasal flexible endoscopy.

METHODS

This bi-centric prospective study was conducted between October 2014 and December 2017. We included consecutive patients with laryngopharyngeal malignant tumors. Transnasal flexible endoscopy was performed by two endoscopists who were blinded to each other's assessments and who examined each patient independently. The first endoscopist only performed a WL examination, while the second endoscopist carried out both WL and NBI. The extent of tumor involvement was reported based on predefined anatomical sub-units. Biopsies in NBI + /WL- sub-units were subsequently performed during panendoscopy.

RESULTS

Eighty-four patients were included in the study. A total of 72 NBI + /WL- sub-units were sampled in 38 patients, and 37 of the biopsies were positive (51.4%): 16 for invasive carcinoma, 17 for high-grade dysplasia/carcinoma in situ and 4 for low-grade dysplasia. Ultimately, 26.2% of patients had at least one positive biopsy in an NBI + /WL- sub-unit and, therefore, a better tumor delineation. The clinical T stage was upgraded in 4.8% of cases examined.

CONCLUSION

Adding NBI to WL imaging during transnasal flexible endoscopy in patients presenting with laryngopharyngeal pre-malignant or malignant lesions improves the delineation of superficial cancer spread, thereby leading to better adapted treatments. Clinicaltrials.gov registration number: NCT02035735.

Margin diagnosis for endoscopic submucosal dissection of early gastric cancer using multiphoton microscopy

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) has become the primary option for the treatment of early gastric cancer (EGC). Thus, it is necessary to diagnose whether residual cancer cells exist in the ESD specimen margins, which can affect tumor recurrence and survival rates in the future. Multiphoton microscopy (MPM) can be suitably used for nondestructive imaging of biological tissue on a cellular level to enable real-time guidance during endoscopic therapy. Considering this, the objective of this study is to explore the practicality of MPM for the diagnosis of ESD specimen margins in the case of EGC.

METHODS

First, a total of 20 surgical samples was imaged using the proposed MPM technique to obtain two-photo excited fluorescence signal from the intrinsic fluorescent substances within cells and second-harmonic generation signal from collagen; these signals were used to determine MPM pathological features for margin diagnosis. Then, a double-blind study of 50 samples was conducted to evaluate the diagnosis results based on the obtained MPM pathological features.

RESULTS

Multiphoton microscopy can accurately identify the cytological and morphological differences between tissue in the negative and positive margin. The sensitivity, specificity, accuracy, negative predictive, and positive predictive values of MPM in the diagnosis of ESD specimen margins were 97.62, 75.00, 94.00, 95.35, and 85.71%, respectively.

CONCLUSION

These results indicate that MPM can be used as an effective, real-time, and label-free novel method to determine intraoperative resection margins.

Should We Resect and Discard Low Risk Diminutive Colon Polyps

Diminutive colorectal polyps <5 mm are very common and almost universally benign. The current strategy of resection with histological confirmation of all colorectal polyps is costly and may increase the risk of colonoscopy. Accurate, optical diagnosis without histology can be achieved with currently available endoscopic technologies. The American Society of Gastrointestinal Endoscopy Preservation and Incorporation of Valuable endoscopic Innovations supports strategies for optical diagnosis of small non neoplastic polyps as long as two criteria are met. For hyperplastic appearing polyps <5 mm in recto-sigmoid colon, the negative predictive value should be at least 90%. For diminutive low grade adenomatous appearing polyps, a resect and discard strategy should be sufficiently accurate such that post-polypectomy surveillance recommendations based on the optical diagnosis, agree with a histologically diagnosis at least 90% of the time. Although the resect and discard as well as diagnose and leave behind approach has major benefits with regard to both safety and cost, it has yet to be used widely in practice. To fully implement such as strategy, there is a need for better-quality training, quality assurance, and patient acceptance. In the article, we will review the current state of the science on optical diagnose of colorectal polyps and its implications for colonoscopy practice.

Efficacy of narrow-band imaging in detecting early esophageal cancer and risk factors for its occurrence

OBJECTIVE

The aim of this study is to evaluate the efficacy of narrow-band imaging (NBI) in the detecting early esophageal cancer and precancerous lesions and to investigate the risk factors for its occurrence.

METHODS

The esophagus was examined with ordinary endoscopy, NBI, and iodine staining. All the lesions were confirmed by histopathologically as the gold standard; NBI and intrapapillary capillary scale (IPCL) scale were compared with pathologic diagnosis. The accuracy, sensitivity, specificity, positive and negative predictive values (PPV, NPV) were calculated. Subgroup analysis was performed between the elderly vs. younger group, and head and neck squamous cell cancer (HNSCC) vs. non-HNSCC patients.

RESULTS

Ninety lesions were detected with ordinary endoscopy, 108 with NBI, and 120 with iodine staining. All esophageal cancers were detected both by NBI and by iodine staining. Accuracy, sensitivity, and specificity for esophageal cancer and precancerous lesion were 67.8%, 58.1%, and 76.6%; 92%, 89.7%, and 96%; 93.4%, 93.4%, and 93.2%, respectively. NBI endoscopy and iodine staining were superior to ordinary endoscopy for detecting esophageal cancer and precancerous lesions (p < 0.05). NBI showed better detection of esophageal neoplasms in the elderly patients (p < 0.001). The incidence of multiple squamous cell cancers (SCCs) was significantly higher in non-elderly group (p = 0.009). NBI can also detect more esophageal neoplastic lesions in patients with head and neck cancers (p = 0.003).

CONCLUSIONS

NBI endoscopy appears as effective as Lugol staining to detect and screen the early esophageal cancer. NBI shows better detection of esophageal neoplasms in the elderly patients. The incidence of multiple SCCs was much higher in non-elderly patients.

The value of narrow band imaging in diagnosis of head and neck cancer: a meta-analysis

Head and neck cancer is difficult to diagnose early. We aimed to estimate the diagnosis value of narrow band imaging(NBI) in head and neck cancers. We identified relevant studies through a search of PubMed, Embase and the Cochrane Library. We used a random effect model. Subgroup analysis and meta-regression analysis were performed to estimate the factors which may influence the sensitivity and specificity of the NBI. We included 25 studies with total 6187 lesions. The pooled sensitivity, specificity, positive likelihood rate, negative likelihood rate and diagnostic odds ratios of NBI were 88.5%, 95.6%, 12.33, 0.11 and 121.26, respectively. The overall area under the curve of SROC was 96.94%. The location, type of assessment, type of endoscope system and high definition were not significant sources of heterogeneity (P > 0.05). However, magnification may be related to the source of heterogeneity (P = 0.0065). Therefore, NBI may be a promising endoscopic tool in the diagnosis of head and neck cancer.

Diagnostic Performance of Narrow Band Imaging for Laryngeal Cancer: A Systematic Review and Meta-analysis

Objective

To evaluate the performance of narrow band imaging (NBI) for the diagnosis of laryngeal cancer and to compare the diagnostic value of NBI with that of white light endoscopy.

Data Sources

PubMed, Embase, Cochrane Library, and CNKI databases.

Review Methods

Data analyses were performed with Meta-DiSc. The updated Quality Assessment of Diagnostic Accuracy Studies–2 tool was used to assess study quality and potential bias. Publication bias was assessed with the Deeks’s asymmetry test. The protocol used in this article has been published on PROSPERO and is in accordance with the PRISMA checklist. The registry number for this study is CRD42015025866.

Results

Six studies including 716 lesions were included in this meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio for the NBI diagnosis of laryngeal cancer were 0.94 (95% confidence interval [95% CI]: 0.91-0.96), 0.89 (95% CI: 0.85-0.92), and 142.12 (95% CI: 46.42-435.15), respectively, and the area under receiver operating characteristics curve was 0.97. Among the 6 studies, 3 evaluated the diagnostic value of white light endoscopy, with a sensitivity of 0.81 (95% CI: 0.76-0.86), a specificity of 0.92 (95% CI: 0.88-0.95), and a diagnostic odds ratio of 33.82 (95% CI: 14.76-77.49). The evaluation of heterogeneity, calculated per the diagnostic odds ratio, gave an I2 of 66%. No marked publication bias ( P = .84) was detected in this meta-analysis.

Conclusion

The sensitivity of NBI is superior to white light endoscopy, and the potential value of NBI needs to be validated in future studies.

White light, autofluorescence and narrow-band imaging bronchoscopy for diagnosing airway pre-cancerous and early cancer lesions: a systematic review and meta-analysis

BACKGROUND

We aimed to summarize the diagnostic accuracy of white light bronchoscopy (WLB) and advanced techniques for airway pre-cancerous lesions and early cancer, such as autofluorescence bronchoscopy (AFB), AFB combined with WLB (AFB + WLB) and narrow-band imaging (NBI) bronchoscopy.

METHODS

We searched for eligible studies in seven electronic databases from their date of inception to Mar 20, 2015. In eligible studies, detected lesions should be confirmed by histopathology. We extracted and calculated the 2×2 data based on the pathological criteria of lung tumor, including high-grade lesions from moderate dysplasia (MOD) to invasive carcinoma (INV). Random-effect model was used to pool sensitivity, specificity, diagnostic odds ratio (DOR) and the area under the receiver-operating characteristic curve (AUC).

RESULTS

In 53 eligible studies (39 WLB, 39 AFB, 17 AFB + WLB, 6 NBI), diagnostic performance for high-grade lesions was analyzed based on twelve studies (10 WLB, 7 AFB, 7 AFB + WLB, 1 NBI), involving with totally 2,880 patients and 8,830 biopsy specimens. The sensitivity, specificity, DOR and AUC of WLB were 51% (95% CI, 34-68%), 86% (95% CI, 73-84%), 6 (95% CI, 3-13) and 77% (95% CI, 73-81%). Those of AFB and AFB + WLB were 93% (95% CI, 77-98%) and 86% (95% CI, 75-97%), 52% (95% CI, 37-67%) and 71% (95% CI, 56-87%), 15 (95% CI, 4-57) and 16 (95% CI, 6-41), and 76% (95% CI, 72-79%) and 82% (95% CI, 78-85%), respectively. NBI presented 100% sensitivity and 43% specificity.

CONCLUSIONS

With higher sensitivity, advanced bronchoscopy could be valuable to avoid missed diagnosis. Combining strategy of AFB and WLB may contribute preferable diagnosis rather than their alone use for high-grade lesions. Studies of NBI warrants further investigation for precancerous lesions.

Development of a novel image-based program to teach narrow-band imaging

OBJECTIVES

Narrow-band imaging (NBI) is a widely available endoscopic imaging technology; however, uptake of the technique could be improved. Teaching new imaging techniques and assessing trainees' performance can be a challenging exercise during a 1-day workshop. To support NBI training, we developed an online training tool (Medimq) to help experts train novices in NBI bronchoscopy that could assess trainees' performance and provide feedback before the close of the 1-day course. The present study determines whether trainees' capacity to identify relevant pathology increases with the proposed interactive testing method.

METHODS

Two groups of 20 and 18 bronchoscopists have attended an NBI course where they did a pretest and post-test before and after the main lecture, and a follow-up test 4 weeks later to measure retention of knowledge. We measured their ability to mark normal and abnormal 'biopsy size' areas on bronchoscopic NBI images for biopsy. These markings were compared with areas marked by experts on the same images.

RESULTS

The first group results were used to pilot the test. After modifications, the results of the improved test for group 2 showed trainees improved by 32% (total class average normalized gain) in detecting normal or abnormal areas. On follow-up testing, Group 2 improved by 23%.

CONCLUSIONS

The overall class average normalized gain of 32% shows our test can be used to improve trainees' competency in analyzing NBI Images. The testing method (and tool) can be used to measure the follow up 4 weeks later. Better follow-up test results would be expected with more frequent practice by trainees after the course.

Emerging role of narrow band imaging in duodenum

Endoscopy using magnification narrow band imaging (mNBI) allows detailed assessment of mucosal surface and vascular pattern. This may help in better identification and prediction of the nature of the lesion. The role of this technology in duodenum is still evolving. Studies have shown that mNBI has high accuracy in predicting villous atrophy in the duodenum. Limited data suggests that this technique can provide additional information on duodenal polyps, nodules and ampullary tumour which can help guide their management. In this paper we describe the technique for duodenal assessment using NBI and review the existing literature evaluating its role in diagnosis of various duodenal pathologies.

Visual evaluation of the larynx and hypopharynx during esophagogastroduodenoscopy: a safety and feasibility study

BACKGROUND

The larynx and hypopharynx are common sites for head and neck cancer, which shares many risk factors with upper digestive tract disease. Patient survival with malignancies depends on stage at the time of diagnosis. Endoscopic screening of the hypopharynx is neither routinely performed in clinical practice nor has it been evaluated in a formal study.

METHODS

This is a prospective pilot study of patients undergoing routine EGD. Demographic data were collected from patients prior to the procedure. All patients in the study underwent an EGD and prior to performing the standard portion of the EGD procedure, the endoscopist evaluated the larynx and hypopharynx with both white light endoscopy (WLE) and narrow band imaging (NBI). Details of the procedure, including ability to see all anatomic structures, time spent, complications, and findings, were recorded.

RESULTS

A total of 111 patients were included in the study. The exam of the laryngopharynx was completed in 87% of patients (97/111). Reasons for incomplete exam included intubated patients (2/14), inadequate sedation (9/14), and inability to see the entire hypopharynx (3/14). The mean time of the WLE was 20.2 s, while the NBI evaluation took 15.6 s for a mean and 35.8 s for the entire exam of the larynx and hypopharynx. Minor procedural complications occurred in 3/11 (2.7%) of the patients and included hypotension, tachycardia, and hypoxia. There were 6 patients who had hypopharyngeal abnormalities seen on both WLE and NBI (5.4%) and were subsequently referred to otolaryngology. Of the six referrals, one patient had a vocal cord biopsy showing leukoplakia, while the others were deemed normal anatomic variants.

CONCLUSIONS

Evaluation of the hypopharynx can be accomplished by gastrointestinal endoscopists at the time of EGD in the vast majority of patients in a safe manner while adding only about 35 s to the overall exam time.

State of the art in advanced endoscopic imaging for the detection and evaluation of dysplasia and early cancer of the gastrointestinal tract

Ideally, endoscopists should be able to detect, characterize, and confirm the nature of a lesion at the bedside, minimizing uncertainties and targeting biopsies and resections only where necessary. However, under conventional white-light inspection – at present, the sole established technique available to most of humanity – premalignant conditions and early cancers can frequently escape detection. In recent years, a range of innovative techniques have entered the endoscopic arena due to their ability to enhance the contrast of diseased tissue regions beyond what is inherently possible with standard white-light endoscopy equipment. The aim of this review is to provide an overview of the state-of-the-art advanced endoscopic imaging techniques available for clinical use that are impacting the way precancerous and neoplastic lesions of the gastrointestinal tract are currently detected and characterized at endoscopy. The basic instrumentation and the physics behind each method, followed by the most influential clinical experience, are described. High-definition endoscopy, with or without optical magnification, has contributed to higher detection rates compared with white-light endoscopy alone and has now replaced ordinary equipment in daily practice. Contrast-enhancement techniques, whether dye-based or computed, have been combined with white-light endoscopy to further improve its accuracy, but histology is still required to clarify the diagnosis. Optical microscopy techniques such as confocal laser endomicroscopy and endocytoscopy enable in vivo histology during endoscopy; however, although of invaluable assistance for tissue characterization, they have not yet made transition between research and clinical use. It is still unknown which approach or combination of techniques offers the best potential. The optimal method will entail the ability to survey wide areas of tissue in concert with the ability to obtain the degree of detailed information provided by microscopic techniques. In this respect, the challenging combination of autofluorescence imaging and confocal endomicroscopy seems promising, and further research is awaited.

Enterobiasis-related inflammatory caecal polyp masquerading as a malignancy

A 55 -year-old Asian man was seen in the emergency department with bleeding per rectum. He was a teetotaller and had no previous abdominal surgery. He did, however, report a change in bowel habit towards constipation. He underwent colonoscopy which revealed a lesion, highly suspicious of malignancy, in the caecum. On review by two consultants, a decision to completely resect this lesion was made. Histological analysis of the polypoidal growth showed it to be a consequence of chronic infection with the helminth Enterobius vermicularis. Importantly, there was no evidence of dysplastic or malignant cells. The patient was subsequently discharged with a 3-day course of antihelminthic mebendazole and reassured that his per rectal bleeding was most likely due to haemorrhoids discovered at rectal examination.

Use of narrow-band imaging in detection of nasopharyngeal carcinoma

Aim:

To compare narrow-band images of nasopharyngeal carcinoma with those of normal adenoidal tissue.

Method:

Patients with a nasopharyngeal mass were evaluated using both conventional white light and narrow-band light. Biopsies were performed and Epstein–Barr viral serology was tested for all patients.

Results:

Thirty consecutive patients were recruited. Twenty-one patients had normal adenoidal tissue and seven had nasopharyngeal carcinoma. One patient with papillary adenocarcinoma was excluded. The features of narrow-band imaging in normal adenoidal tissue were: (1) a regularly arranged follicular pattern, and (2) each ‘follicle’ comprising a pale centre with surrounding dark periphery. The features of narrow-band imaging in nasopharyngeal carcinoma were: (1) absence of surface patterns (n = 7), and/or (2) ‘reverse’, haphazard follicular pattern comprising a dark brown centre and pale periphery (n = 3).

Conclusion:

Narrow-band imaging of the surface of adenoidal tissue and nasopharyngeal carcinoma appears to identify distinct, characteristic features as described. Narrow-band imaging may be a useful adjunct in differentiating normal adenoidal tissue from malignancy. Further studies are needed to evaluate its diagnostic accuracy.

Diagnostic accuracy of narrow-band imaging for the differentiation of neoplastic from non-neoplastic colorectal polyps: a meta-analysis

AIM

Narrow-band imaging (NBI) is a novel imaging technology that makes the superficial vasculature of gastrointestinal mucosa visible. However, the real accuracy for the differentiation of neoplastic from non-neoplastic polyps by NBI for the colorectum is still unknown.

METHOD

A meta-analysis was carried out of studies which assessed the precision of NBI in the diagnosis of colorectal neoplastic polyps. Searches included PubMed and Embase and two reviewers independently assessed their quality with a modified version of the quadas and stard tools. The study pooled estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and area under the curve (AUC).

RESULTS

There were 11 relevant original papers which fulfilled the inclusion criteria. The pooled sensitivity and specificity were 0.92 (95% CI 0.90-0.93) and 0.83 (95% CI 0.81-0.86) respectively. The AUC for NBI was 0.95 [SE 0.01; DOR 53.72 (95% CI 35.66-80.92)]. The sensitivity and specificity were 0.92 (95% CI 0.90-0.94) and 0.81 (95% CI 0.78-0.84) with magnification, and 0.91 (95% CI 0.88-0.93) and 0.86 (95% CI 0.82-0.89) without magnification. For the mucosal pattern sensitivity and specificity were 0.90 (95% CI 0.85-0.940) and 0.88 (95% CI 0.82-0.93), and for vascular pattern intensity they were 0.92 (95% CI 0.90-0.94) and 0.88 (95% CI 0.83-0.91).

CONCLUSION

Narrow-band imaging, with or without magnification, has a high diagnostic precision for colorectal neoplastic polyps using either vascular pattern intensity or mucosal pattern assessment as the measure.

Relation between vascular patterns visualized by Narrow Band Imaging (NBI) videobronchoscopy and histological type of lung cancer

Narrow Band Imaging (NBI) videobronchoscopy is a new technique for visualization of microvascular changes in bronchial mucosa. The primary aim of this study was to evaluate relation between vascular patterns visualized by NBI and histology of lung cancer. We prospectively evaluated 65 patients with suspected lung cancer scheduled for bronchoscopy. NBI followed conventional WL videobronchoscopy. After identification of endoscopically visible tumor, NBI was used to determine predominant type of pathological vascular pattern (dotted, tortuous, abrupt-ending blood vessels-Shibuya descriptors). All the lesions were biopsied and histologically confirmed. There were 81.5 % male and 18.5 % female patients evaluated in the study. Lung cancer was confirmed in all patients; 63.1 % were diagnosed with squamous cell lung cancer (SCC), 24.6 % had adenocarcinoma, 9.2 % had small-cell (SCLC) and 3.1 % large-cell lung cancer (LC). Dotted blood vessels were significantly (p < 0.000) associated with adenocarcinoma, identified in 68.4 % adenocarcinoma and 31.6 % SCC. Tortuous blood vessels were identified in 72 % SCC, 8 % adenocarcinoma, 12 % SCLC and 8 % of LC. Tortuous blood vessels were significantly (p < 0.000) associated with SCC. Abrupt-ending vessels were identified in 81 % SCC, 14.3 % SCLC and 4.8 % adenocarcinoma and were significantly associated (p < 0.000) with SCC. Dotted visual pattern of blood vessels identified during NBI videobronchoscopy is highly suggesting adenocarcinoma histology of lung cancer. Tortuous and abrupt-ending blood vessels visualized under NBI videobronchoscopy significantly suggest squamous cell histology of lung cancer. Large-scale studies should be designed in order to determine true relation between visual appearance and histology in lung cancer.

Application of magnifying endoscopy with narrow-band imaging in diagnosing gastric lesions: a prospective study

BACKGROUND

Magnifying endoscopy with narrow-band imaging (ME-NBI) can more clearly assess the surface pattern and microvascular architecture of gastric lesions.

OBJECTIVE

To evaluate the diagnostic efficacy of ME-NBI in patients with early gastric cancer.

DESIGN

Prospective study.

SETTING

Single academic center.

PATIENTS

This study involved 164 suspected gastric lesions in 146 consecutive patients who underwent ME-NBI for additional differential diagnosis before treatment.

INTERVENTION

ME-NBI findings were classified into 3 groups based on irregularities, absence of surface pattern, and microvascular architecture. All lesions were treated endoscopically or surgically, and ME-NBI diagnosis was compared with histopathological findings.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of real-time ME-NBI diagnosis were determined.

RESULTS

The sensitivity, specificity, and accuracy of ME-NBI were 97.3%, 84.4%, and 90.2%, respectively, in distinguishing between cancerous and noncancerous lesions and were 92.3%, 89.7%, and 90.4%, respectively, in distinguishing undifferentiated from differentiated adenocarcinoma. ME-NBI accurately predicted depth of invasion in 37 of 39 differentiated adenocarcinomas (95%).

LIMITATIONS

The sample size was relatively small.

CONCLUSIONS

ME-NBI can successfully distinguish between cancerous and noncancerous lesions and between undifferentiated and differentiated adenocarcinomas. Of the 3 patterns on ME-NBI, type A is mainly characteristic of noncancerous lesions, type B is a good indicator of differentiated adenocarcinoma and intramucosal/superficially invasive cancers, and type C is indicative of undifferentiated adenocarcinoma or differentiated cancer with deep submucosal invasion.

Digital chromoendoscopy for diagnosis of diminutive colorectal lesions

Introduction. To compare the accuracy of digital and real-time chromoendoscopy for the differential diagnosis of diminutive (<5 mm) neoplastic and nonneoplastic colorectal lesions. Materials and Methods. This is a prospective randomized study comparing the Fujinon intelligent color enhancement (FICE) system (65 patients/95 lesions) and indigo carmine (69 patients/120 lesions) in the analysis of capillary meshwork and pit pattern, respectively. All lesions were less than 5 mm in diameter, and magnification was used in both groups. Histopathology was the gold standard examination. Results. Of 215 colorectal lesions, 153 (71.2%) were adenomas, and 62 were hyperplastic polyps (28.8%). Morphological analysis revealed 132 (61.4%) superficial lesions, with 7 (3.3%) depressed lesions, and 83 (38.6%) protruding lesions. Vascular meshwork analysis using FICE and magnification resulted in 91.7% sensitivity, 95.7% specificity, and 92.6% accuracy in differentiating neoplastic from nonneoplastic lesions. Pit pattern analysis with indigo carmine and magnification showed 96.5% sensitivity, 88.2% specificity, and 94.2% accuracy for the same purpose. Conclusion. Both magnifying virtual chromoendoscopy and indigo carmine chromoendoscopy showed high accuracy in the histopathological diagnosis of colorectal lesions less than 5 mm in diameter.

Efficacy of computed image modification of capsule endoscopy in patients with obscure gastrointestinal bleeding

AIM: To investigate whether flexible spectral color enhancement (FICE) improves diagnostic yields of capsule endoscopy (CE) for obscure gastro-intestinal bleeding (OGIB).

METHODS: The study subjects consisted of 81 patients. Using FICE, there were three different sets with different wavelengths. Using randomly selected sets of FICE, images of CE were evaluated again by two individuals who were not shown the conventional CE reports and findings. The difference between FICE and conventional imaging was examined.

RESULTS: The overall diagnostic yields in FICE sets 1, 2, 3 and conventional imaging (48.1%) were 51.9%, 40.7%, 51.9% and 48.1%, respectively, which showed no statistical difference compared to conventional imaging. The total numbers of detected lesions per examination in FICE imaging and conventional imaging were 2.5 ± 2.1 and 1.8 ± 1.7, respectively, which showed a significant difference (P = 0.01).

CONCLUSION: The diagnostic yield for OGIB is not improved by FICE. However, FICE can detect significantly more small bowel lesions compared to conventional imaging.

Meta-analysis: the diagnostic accuracy of lactose breath hydrogen or lactose tolerance tests for predicting the North European lactase polymorphism C/T-13910

BACKGROUND

  The diagnostic accuracy of two indirect tests of lactose digestion, lactose breath hydrogen and lactose tolerance tests, have not been systematically reviewed for comparison with available publications on genotype.

AIM

  To perform a meta-analysis of available studies that compares the north-European genetic polymorphism C/T-13910 with the lactose breath hydrogen and the lactose tolerance tests, to determine their ability to predict geno/phenotype relationships. We examine the effects of lactose loading dose, inclusion of children and latitudes of study centre on comparative outcome.

METHODS

  An electronic database of the literature as well as individual references in articles were searched with the theme of genetics of lactase and comparisons with breath or lactose tolerance tests were carried out. Random effect and fixed effect models were used for breath and lactose tolerance tests respectively, to report summary accuracy measures with 95% confidence intervals (CI).

RESULTS

  The search revealed 19 studies: 17 evaluated breath hydrogen, five lactose tolerance test (3/17 overlapped). Overall sensitivity was 0.88 (CI, 0.85-0.90), specificity was 0.85 (CI, 0.82-0.87) for breath test. Heterogeneity was explored by adjusting for studies including children, high or low dose lactose and to some extent by site of study. The lactose tolerance test showed sensitivity of 0.94 (0.9-0.97) and specificity of 0.90 (0.84-0.95) with a nonsignificant heterogeneity.

CONCLUSION

  The diagnostic accuracy of both tests individually reflects expected geno/phenotypes when the populations are well defined.

Narrow band imaging versus conventional white light colonoscopy for the detection of colorectal polyps

BACKGROUND

It has been suggested that narrow band imaging colonoscopy (NBI) might be better for detection of colorectal polyps than white light colonoscopy (WLC).

OBJECTIVES

To compare standard or high definition white light colonoscopy with narrow band imaging colonoscopy for detection of colorectal polyps.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, and EMBASE to August 2011. We scanned bibliographies of relevant publications and wrote to experts for additional trials.

SELECTION CRITERIA

Two authors (NA and GB) independently applied the inclusion criteria and extracted the data to all potential studies without blinding.

DATA COLLECTION AND ANALYSIS

Authors extracted data independently. Trials with adequate randomisation, allocation concealment, and complete outcome data reporting, as well as without selective outcome reporting or other bias were classified as having a lowest risk of bias. Random-effects and fixed-effect meta-analyses were conducted.

MAIN RESULTS

We identified 11 randomised trials comparing WLC with NBI for detection of colorectal polyps. In total eight randomised trials with 3673 participants provided data for our analyses. There was no statistically significant difference between WLC (standard definition and high definition pooled) and NBI for the detection of patients with colorectal polyps (6 trials, n = 2832, RR 0.97, 95% CI 0.91 to 1.04), patients with colorectal adenomas (8 trials, n = 3673, RR 0.94, 95% CI 0.87 to 1.02), or patients with colorectal hyperplastic polyps (2 trials, n = 645, RR 0.87, 95% CI 0.76 to 1.00). Number of patients with at least one colorectal adenoma was not significantly different between WLC and NBI group irrespective of adenoma size (< 5 mm:RR 0.95, 95% CI 0.84 to 1.08, I(2) = 56%; 6 to 9 mm: RR 1.06, 95% CI 0.81 to 1.39, I(2) = 0%; ≥ 10 mm: RR 1.06, 95% CI 0.77 to 1.45, I(2) = 0%). Number of patients with at least one colorectal polyp, or colorectal adenoma was significantly lower in the standard definition WLC group compared to NBI group in fixed-effect meta-analysis (RR 0.87, 95% CI 0.78 to 0.97, I(2) = 78%; RR 0.87, 95% CI 0.77 to 0.99, I(2) = 0%, respectively), but not significantly different in random-effects meta-analysis (RR 0.86, 95% CI 0.68 to 1.10, I(2) = 78%). There was no statistically significant difference between high definition WLC and NBI in the number of patiens with at least one colorectal polyp or colorectal adenoma (RR 1.10, 95% CI 0.95 to 1.28; RR 0.87, 95% CI 0.77 to 0.99, I(2) = 0%, respectively).

AUTHORS' CONCLUSIONS

We could not find convincing evidence that NBI is significantly better than high definition WLC for the detection of patients with colorectal polyps, or colorectal adenomas. We found evidence that NBI might be better than standard definition WLC and equal to high definition WLC for detection the patients with colorectal polyps, or colorectal adenomas.

Chromoendoscopy in small bowel capsule endoscopy: Blue mode or Fuji Intelligent Colour Enhancement?

INTRODUCTION

Virtual chromoendoscopy is used to enhance surface patterns and colour differences. One type of virtual chromoendoscopy is the Fuji Intelligent Colour Enhancement (FICE). Although widely applied in conventional endoscopy, data on FICE application in capsule endoscopy are limited. Furthermore, the validity of Blue filter (feature of RAPID(®) software) has not been examined. AIM/S: We aimed to qualitatively evaluate the use of FICE and Blue filter enhancement, in images of lesions obtained during small bowel capsule endoscopy, comparing them with similar, conventional (white light) images.

METHODS

A total of 167 images (6 different lesion categories) obtained from 200 capsule endoscopy examinations. Two gastroenterologists examined the images with white light, FICE and Blue filter in regards to the visibility of blood vessels, the contrast of the mucosal surface, and the demarcation of lesion borders. The agreed scores were: improved, similar, worse. Inter-observer agreement was calculated.

RESULTS

For all lesion categories, Blue filter provided image improvement (compared to white light) in 83%, (inter-observer agreement: 0.786). With FICE 1, improvement was observed in 34%, worse image in 55.9%, (inter-observer agreement: 0.646). With FICE 2, improvement was observed in 8.6%, worse in 77.5%, (inter-observer agreement: 0.617). With FICE 3, improvement was seen in 7.7%, worse in 79.9% (inter-observer agreement: 0.669).

CONCLUSION

Comparing with FICE, Blue filter offers better image enhancement in capsule endoscopy.

Endoscopic findings under narrow band imaging colonoscopy in ulcerative colitis

Narrow band imaging (NBI) depicts distinct intramucosal vascular network and pit pattern without any use of dye technique. It is thus suggested that NBI can be used for the assessment of severity in inflammatory bowel diseases, especially in ulcerative colitis (UC). In the active UC, NBI colonoscopy depicts friability as a black area. In the inflamed granular mucosa, crypt openings and villous structure become evident through the procedure. In the inactive UC, there are two types of mucosal vascular pattern; one being composed of deep, green vessels and superficial, black vessels, and the other lacking in superficial vessels. With used of a magnifying instrument, the mildly active mucosa can be classified into the mucosa with obvious crypt openings and that with villous structure. Mucosal vascular pattern in the inactive mucosa is shown as a honeycomb-like structure or irregular, tortuous structure under magnifying NBI observation. Furthermore, such NBI findings show close correlations with histologic findings including crypt distortion, goblet cell depletion and basal plasmacytosis. Therefore, NBI colonoscopy might be of value for the precise assessment of histologic severity in mildly active and inactive UC.

Narrow band imaging for the detection of gastric intestinal metaplasia and dysplasia during surveillance endoscopy

Background Surveillance of premalignant gastric lesions relies mainly on random biopsy sampling. Narrow band imaging (NBI) may enhance the accuracy of endoscopic surveillance of intestinal metaplasia (IM) and dysplasia.We aimed to compare the yield of NBI to white light endoscopy (WLE) in the surveillance of patients with (IMa)and dysplasia.Methods Patients with previously identified gastric IM or dysplasia underwent a surveillance endoscopy. Both WLE and NBI were performed in all patients during a single procedure. The sensitivity of WLE and NBI for the detection of premalignant lesions was calculated by correlating endoscopic findings to histological diagnosis.Results Forty-three patients (28 males and 15 females,mean age 59 years) were included. IM was diagnosed in 27 patients; 20 were detected by NBI and WLE, four solely by NBI and three by random biopsies only. Dysplasia was detected in seven patients by WLE and NBI and in two patients by random biopsies only. Sixty-eight endoscopically detected lesions contained IM: 47 were detected by WLE and NBI, 21 by NBI only. Nine endoscopically detected lesions demonstrated dysplasia: eight were detected by WLE and NBI, one was detected by NBI only.The sensitivity, specificity, positive and negative predictive values for detection of premalignant lesions were 71, 58,65 and 65% for NBI and 51, 67, 62 and 55% for WLE,respectively.Conclusions NBI increases the diagnostic yield for detection of advanced premalignant gastric lesions compared to routine WLE.

Endoscopic diagnosis of laryngeal cancer and precancerous lesions by narrow band imaging

Objective:

To investigate the characteristics of the laryngeal mucosal microvascular network in suspected laryngeal cancer patients, using narrow band imaging, and to evaluate the value of narrow band imaging endoscopy in the early diagnosis of laryngeal precancerous and cancerous lesions.

Patients and methods:

Eighty-five consecutive patients with suspected precancerous or cancerous laryngeal lesions were enrolled in the study. Endoscopic narrow band imaging findings were classified into five types (I to V) according to the features of the mucosal intraepithelial papillary capillary loops assessed.

Results:

A total of 104 lesions (45 malignancies and 59 nonmalignancies) was detected under white light and narrow band imaging modes. The sensitivity and specificity of narrow band imaging in detecting malignant lesions were 88.9 and 93.2 per cent, respectively. The intraepithelial papillary capillary loop classification, as determined by narrow band imaging, was closely associated with the laryngeal lesions' histological findings. Type I to IV lesions were considered nonmalignant and type V lesions malignant. For type Va lesions, the sensitivity and specificity of narrow band imaging in detecting severe dysplasia or carcinoma in situ were 100 and 79.5 per cent, respectively. In patients with type Vb and Vc lesions, the sensitivity and specificity of narrow band imaging in detecting invasive carcinoma were 83.8 and 100 per cent, respectively.

Conclusion:

Narrow band imaging is a promising approach enabling in vivo differentiation of nonmalignant from malignant laryngeal lesions by evaluating the morphology of mucosal capillaries. These results suggest endoscopic narrow band imaging may be useful in the early detection of laryngeal cancer and precancerous lesions.

Computerized virtual chromoendoscopy versus indigo carmine chromoendoscopy combined with magnification for diagnosis of small colorectal lesions: a randomized and prospective study

BACKGROUND AND STUDY AIMS

Magnifying colonoscopy with indigo carmine dye and the analysis of the capillary and the pit patterns by computed virtual chromoendoscopy (Fujinon Intelligent Color Enhancement, FICE) with magnification are effective for the differential diagnosis of neoplastic and non-neoplastic lesions. This study aimed to compare the accuracy of virtual and real chromoendoscopy in differentiating neoplastic and non-neoplastic colorectal lesions.

PATIENTS AND METHODS

A prospective randomized trial of magnification colonoscopy with targeted FICE (Group I - 72 patients/111 lesions) versus magnification colonoscopy with targeted indigo carmine dye (Group II - 72 patients/137 lesions) was performed in consecutive patients with lesions 1 cm or less. Histopathology of the specimens was regarded as the gold standard.

RESULTS

In group I, 86 (77.5%) lesions showed an intense vascular pattern (positive capillary meshwork), of which 80 (93%) were histologically confirmed as adenomas. From 25 lesions with negative capillary meshwork, 23 (92%) were non-neoplastic. Sensitivity, specificity, accuracy, positive and negative predictive values of the capillary meshwork for the differential diagnosis of these lesions was 97.8, 79.3, 92.8, 93 and 92%, respectively. The same parameters for pit pattern analysis by FICE were 92.7, 82.3, 90.1, 93.8 and 80%, respectively. Indigo carmine magnified chromoscopy showed sensitivity, specificity, accuracy, positive and negative predictive values of 97, 88.9, 94.9, 96.1 and 91.4%, respectively in the discrimination between neoplastic and non-neoplastic lesions.

CONCLUSION

Magnified virtual chromoendoscopy is as accurate as indigo carmine magnified chromoendoscopy in distinguishing between neoplastic from non-neoplastic small colorectal lesions.

Narrow-band imaging endoscopy to assess mucosal angiogenesis in inflammatory bowel disease: A pilot study

AIM: To investigate whether narrow band imaging (NBI) is a useful tool for the in vivo detection of angiogenesis in inflammatory bowel disease (IBD) patients.

METHODS: Conventional and NBI colonoscopy was performed in 14 patients with colonic inflammation (8 ulcerative colitis and 6 Crohn’s disease). Biopsy samples were taken and CD31 expression was assayed immunohistochemically; microvascular density was assessed by vessel count.

RESULTS: In areas that were endoscopically normal but positive on NBI, there was a significant (P < 0.05) increase in angiogenesis (12 ± 1 vessels/field vs 18 ± 2 vessels/field) compared with areas negative on NBI. In addition, in areas that were inflamed on white light endoscopy and positive on NBI, there was a significant (P < 0.01) increase in vessel density (24 ± 7 vessels/field) compared with NBI-negative areas.

CONCLUSION: NBI may allow in vivo imaging of intestinal angiogenesis in IBD patients.

Intraperitoneal virtual biopsy by fibered optical coherence tomography (OCT) at natural orifice transluminal endoscopic surgery (NOTES)

INTRODUCTION

Fibered optical coherence tomography (OCT) in conjunction with natural orifice transluminal endoscopic surgery (NOTES) could provide a facility for rapid, in situ pathological diagnosis of intraperitoneal tissues in a truly minimally invasive fashion.

MATERIALS AND METHODS

A large porcine model was established to test this hypothesis. A standard double channel gastroscope (Olympus) was used to achieve a transgastric access to the peritoneum and initiate the pneumoperitoneum. Magnetic retraction was used to display the sigmoid colon along with its mesentery. A commercially available fibered OCT probe (NIRIS system, Imalux) was inserted via a working channel of the gastroscope and used to assess intraperitoneal tissues. Separately, OCT images of human tissue specimens ex vivo were contrasted with representative standard histopathological slides.

RESULTS

Intraperitoneal OCT provided clear real-time images of both the serosal and muscularis propria mural layers as well as the submucosal-muscularis interface. Examination of mesenteric lymph nodes (including sentinel nodes) allowed visualization of their subcapsular sinus. Comparison of representative cross-sections however failed to evince sufficient resolution for confident diagnosis.

CONCLUSION

This approach is technically feasible and, if the technology is advanced and proven accurate in human patients, could potentially be used to individualize operative extent prior to definitive resection.

Optical diagnosis of small colorectal polyps at routine colonoscopy (Detect InSpect ChAracterise Resect and Discard; DISCARD trial): a prospective cohort study

BACKGROUND

Accurate optical diagnosis of small (<10 mm) colorectal polyps in vivo, without formal histopathology, could make colonoscopy more efficient and cost effective. The aim of this study was to assess whether optical diagnosis of small polyps is feasible and safe in routine clinical practice.

METHODS

Consecutive patients with a positive faecal occult blood test or previous adenomas undergoing surveillance at St Mark's Hospital (London, UK), from June 19, 2008, to June 16, 2009, were included in this prospective study. Four colonoscopists with different levels of experience predicted polyp histology using optical diagnosis with high-definition white light, followed by narrow-band imaging without magnification and chromoendoscopy, as required. The primary outcome was accuracy of polyp characterisation using optical diagnosis compared with histopathology, the current gold standard. Accuracy of optical diagnosis to predict the next surveillance interval was also assessed and compared with surveillance intervals predicted by current guidelines using histopathology. This study is registered with ClinicalTrials.gov, NCT00888771.

FINDINGS

363 polyps smaller than 10 mm were detected in 130 patients, of which 278 polyps had both optical and histopathological diagnosis. By histology, 198 of these polyps were adenomas and 80 were non-neoplastic lesions (of which 62 were hyperplastic). Optical diagnosis accurately diagnosed 186 of 198 adenomas (sensitivity 0.94; 95% CI 0.90-0.97) and 55 of 62 hyperplastic polyps (specificity 0.89; 0.78-0.95), with an overall accuracy of 241 of 260 (0.93, 0.89-0.96) for polyp characterisation. Using optical diagnosis alone, 82 of 130 patients could be given a surveillance interval immediately after colonoscopy, and the same interval was found after formal histopathology in 80 patients (98%) using British guidelines and in 78 patients (95%) using US multisociety guidelines.

INTERPRETATION

For polyps less than 10 mm in size, in-vivo optical diagnosis seems to be an acceptable strategy to assess polyp histopathology and future surveillance intervals. Dispensing with formal histopathology for most small polyps found at colonoscopy could improve the efficiency of the procedure and lead to substantial savings in time and cost.

FUNDING

Leigh Family Trust, London, UK.

[Virtual chromoendoscopy]

Precise endoscopic assessment of gastrointestinal mucosal features is important in order to detect neoplastic lesions at an early stage. Electronic virtual chromoendoscopy markedly improves capillary pattern contrast and is an in vivo method for visualizing microvessel morphological changes in superficial neoplastic lesions. The scientific basis for this technique is that short wavelength light falls within the hemoglobin absorption band, thereby facilitating clearer visualization of vascular structures and pit pattern. Narrow Band Imaging (NBI, Olympus) and Multi-Band Imaging (FICE) are real-time, on-demand endoscopic imaging techniques available with high-definition endoscope. Potential indications include both the detection of premalignant lesions and differentiation between neoplastic and non-neoplastic lesions. The ease and readiness of use and the routine availability of virtual chromoendoscopy will probably contribute to its popularity. This does not alleviate the need to better define the role of these techniques in daily endoscopy practice by conducting well-designed prospective studies.

Improving visualization techniques by narrow band imaging and magnification endoscopy

Endoscopy plays an important role in the early detection of gastrointestinal tract neoplasms. Using conventional white light or dye-based image enhanced endoscopy, it has been difficult to assess pre-malignant and early neoplastic lesions precisely. However, narrow band imaging (NBI) dramatically improves the detection of these lesions, particularly in combination with magnifying endoscopy. This allows the endoscopist to accomplish accurate diagnosis. Such enhanced detection of pre-malignant and early neoplastic lesions in the gastrointestinal tract should allow better targeting of biopsy, improved and more appropriate treatment, and thereby contribute to optimal quality of life and patient survival.