Narrow-band imaging of the gastrointestinal tract

Magnified endoscopy with texture and color enhanced imaging with indigo carmine for superficial nonampullary duodenal tumor: a pilot study

This pilot study aimed to investigate the utility of texture and color enhancement imaging (TXI) with magnified endoscopy (ME) for the preoperative diagnosis of superficial nonampullary duodenal epithelial tumors (SNADETs). We prospectively evaluated 12 SNADETs. The visibility for ME-TXI, ME with indigo carmine (ICME)—white-light imaging (WLI), ICME-TXI compared to ME-NBI (narrow-band imaging) was scored (+ 2 to − 2 ME-NBI was set as score 0) by 3 experts. Scores + 2 and + 1 were defined as improved visibility. The intra-observer and interobserver agreement for improved visibility of surface structure (SS) was evaluated. Sensitivity, specificity, and positive predictive value (PPV) for Vienna Classification (VCL) C4/5 associated with the preoperative diagnosis of ICME-TXI were analyzed. The SS visibility score of ICME-TXI was significantly higher than that of ME-NBI, ME-TXI, and ICME-WLI (P < 0.001 respectively). The kappa coefficients of reliability for intra-observer and interobserver agreement for the SS visibility improvement with ICME-TXI were 0.96, 1.00, 1.00 and 0.70, 0.96, 0.96 respectively. All endoscopists preferred ICME-TXI for visualizing SS mostly for all lesions. The sensitivity, specificity, and PPV (%) of ICME-TXI for VCL C4/5 were 80, 66.7, and 63.2, respectively. ICME-TXI facilitates the visibility of the SS of SNADETs and may contribute to their preoperative diagnosis.

Real-time fluorescence image-guided gastrointestinal oncologic surgery: Towards a new era

Technological improvements are crucial in the evolution of surgery. Real-time fluorescence-guided surgery (FGS) has spread worldwide, mainly because of its usefulness during the intraoperative decision-making processes. The success of any gastrointestinal oncologic resection is based on the anatomical identification of the primary tumor and its regional lymph nodes. FGS allows also to evaluate the blood perfusion at the gastrointestinal stumps after colorectal or esophageal resections. Therefore, a reduction on the anastomotic leak rates has been postulated as one of the foreseeable benefits provided by the use of FGS in these procedures. Although the use of fluorescence in lymph node detection was initially described in breast cancer surgery, the technique is currently applied in gastric or splenic flexure cancers, as they both present complex and variable lymphatic drainages. FGS allows also to perform intraoperative lymphograms or sentinel lymph node biopsies. New applications of FGS are being developed to assist in the detection of peritoneal metastases or in the evaluation of the tumor resection margins. The present review aims to provide a general overview of the current status of real-time FGS in gastrointestinal oncologic surgery. We put a special focus on the different applications of FGS, discussing the main findings and limitations found in the contemporary literature and also the promising near future applications.

Narrow-band Imaging Examination of Microvascular Architecture of Subcapsular Hepatic Tumors

BACKGROUND

Intraoperative ultrasonography is the golden standard method for evaluation of liver tumors during hepatectomy. However, in laparoscopic surgery, accurate assessment of tumors may be difficult, particularly if the lesion is located nearby the liver surface because of the challenges in handling the intraoperative ultrasound and the lack of tactile sensation. In this study, we demonstrate the preliminary results of examining the microvascular architecture of subcapsular hepatic tumors using laparoscopic narrow-band imaging (NBI) to distinguish between malignant and benign tumors.

MATERIALS AND METHODS

Thirty-five lesions were examined by NBI during laparoscopic hepatectomy for the presence of abnormal microvasculature on the liver surface in relation to hepatic tumors from January 2016 to August 2018. The microvascular findings were correlated with tumor localization and pathological diagnosis.

RESULTS

The 35 examined nodules included 11 hepatocellular carcinoma, 18 colorectal liver metastasis, and six benign nodules. The mean tumor diameter was 26.3 (3-70) mm, and the distance from the liver surface to the tumor was 0.5 (0-5) mm. Microvessels on the liver surface were clearly visualized by NBI, consistent with malignant tumor localization. The tumors were thoroughly examined for the presence of three pathological microvascular features (enlargement, tortuosity, and heterogeneity). Abnormal microvascular patterns were found in 90.9% of hepatocellular carcinoma and 77.8% of colorectal liver metastasis, whereas neither normal sites nor benign lesions displayed microvascular abnormality.

CONCLUSIONS

This study suggests that observing the microvessel image on the liver surface by NBI could be useful in tumor localization and differentiation between benign and malignant lesions.

Esophageal squamous cell carcinoma or high-grade dysplasia overlying leiomyoma, rare but not to be neglected

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) and leiomyoma are common tumors. The coexistence of these two tumors can be classified into two types: the overlying type and the separate type. The overlying type is rare.

METHODS

We report 12 cases of the overlying type treated by endoscopic submucosal dissection (ESD). They underwent pre-ESD endoscopic examination with white-light imaging, iodine staining, narrow-band imaging, endoscopic ultrasound, and biopsy. The clinical, endoscopic and pathologic characteristics were reviewed.

RESULTS

Among the 12 patients, 3 were female and 9 were male. The age range was 49-76 years. They accounted for 4.0% of 300 cases of esophageal leiomyoma and 1.3% of 955 cases of superficial ESCC or high-grade dysplasia treated by endoscopic resection. After endoscopic examination and biopsy, ESCC or high-grade dysplasia, combined with leiomyoma was considered in four cases; leiomyoma was considered but without the squamous lesion (underdiagnosis) in another case; and leiomyoma was mistaken for submucosal ESCC (overdiagnosis) in the other seven cases. ESD specimens showed that nine cases were intramucosal or submucosal ESCC, and three cases were high-grade dysplasia, overlying leiomyoma originating from the muscularis mucosae or muscularis propria. The 12 cases were successfully treated by ESD, with no recurrence during follow-up.

CONCLUSIONS

We must keep in mind that ESCC or high-grade dysplasia can occur overlying leiomyoma. These cases are rare but should not be neglected, especially in high-risk areas for ESCC. These patients can receive appropriate treatment if overdiagnosis or underdiagnosis can be avoided.

Narrow-Band Imaging Improves Detection of Colorectal Peritoneal Metastases: A Clinical Study Comparing Advanced Imaging Techniques

Background

Colorectal peritoneal metastases (PM) are often diagnosed in an advanced disease stage. Cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) improve survival of patients with colorectal PM, although most benefit is seen in patients with limited peritoneal disease. Advanced imaging techniques might improve the detection of PM, potentially leading to earlier diagnosis and improved cytoreduction. This prospective clinical trial compared three advanced techniques with conventional white-light imaging for the detection of colorectal PM: narrow-band imaging (NBI), near-infrared indocyanine green fluorescent imaging (NIR-ICG), and spray-dye chromoendoscopy (SDCE).

Methods

Patients with colorectal PM were prospectively included. Prior to cytoreduction and HIPEC, all abdominal regions were inspected with white-light imaging, NBI, NIR-ICG, and SDCE during exploratory laparoscopy. Primary endpoints were sensitivity and specificity for the detection of PM, using pathological examination of biopsied lesions as the reference standard. The safety of all techniques was assessed.

Results

Between May 2016 and March 2018, four different techniques were analyzed in 28 patients, resulting in 169 biopsies. Sensitivity for the detection of PM significantly increased from 80.0% with white light to 96.0% with NBI (p = 0.008), without loss of specificity (74.8% vs. 73.1%, respectively, p = 0.804). The use of NIR-ICG and SDCE was discontinued after 10 patients had undergone treatment because the lesions were not fluorescent using NIR-ICG, and because SDCE did not visualize the whole peritoneum. No adverse events relating to the imaging techniques occurred.

Conclusion

NBI substantially increased the detection of PM. This method is safe and could improve the detection of metastatic lesions and help optimize cytoreduction in patients with colorectal PM.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-7005-5) contains supplementary material, which is available to authorized users.

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.

Differential diagnosis of colorectal polyps with narrow band imaging colonoscopy without magnification

BACKGROUND/AIMS

Narrow band imaging (NBI) endoscopy can be used for gross differentiation between the types of colonic polyps. This study was conducted as a retrospective study for estimation of the interobserver and intra-observer agreement of the pit pattern of the mucosal surface and the accuracy of histology prediction.

METHODS

A total of 159 patients underwent complete colonoscopy and 219 polyps examined by NBI endoscopy without magnification were assessed. Interobserver and intra-observer agreement were calculated by investigators in each group for determination of the surface pattern and prediction of histology based on the modified Kudo's classification using intraclass correlation coefficient.

RESULTS

Interobserver agreement for the surface pit pattern and prediction of polyp type was 0.84 and 0.73 in experienced endoscopists, and 0.86 and 0.62 in trainees, respectively. Intra-observer agreement for the surface pit patterns and prediction of polyp type was 0.81, 0.83, 0.85, 0.83, 0.56, 0.84, 0.51, 0.83, and 0.71; and 0.71, 0.70, 0.82, 0.54, 0.72, 0.37, 0.51, 0.34, and 0.30, respectively. The diagnostic accuracy for prediction of polyp type was 69.4% for experienced endoscopists and 72.9% for trainees.

CONCLUSIONS

NBI endoscopy without magnification showed fairly good inter and intra-observer agreement for the pit pattern of the mucosal surface and the accuracy of histology prediction; however, it had some limitation for differentiation of colon polyp histologic type. Training and experience with NBI is needed for improvement of accuracy.

Intentional examination of esophagus by narrow-band imaging endoscopy increases detection rate of cervical inlet patch

Foci of heterotopic gastric mucosa have been identified at different sites in the human body and the most common location is the proximal esophagus which is referred to as cervical inlet patch (CIP). The true prevalence of CIP varies and it is usually incidental findings during endoscopy. Because CIP is always asymptomatic, it was believed to be of little clinical relevance. However, emerging studies have described the acid-secreting characteristics of heterotopic gastric mucosa and associations of CIP with gastroesophageal reflux disease (GERD). In addition, complications such as stricture, fistula, infection, mucosal hyperplasia, and malignant transformation have been reported. In this study, we investigated the prevalence of CIP, its associations with clinical manifestations, and the effect of intentional screening upper esophagus by magnifying endoscopy-narrow-band imaging (ME-NBI) system. Consecutive healthy adults who underwent panendoscopy were separated into two groups. Patients in group I (n = 471) were examined by an endoscopist who intended to find CIPs by ME-NBI. Patients in group II (n = 428) were examined by two endoscopists who were unaware of the study and performed white-light imaging endoscopy. Participants provided questionnaires on GERD-related symptoms. Higher CIP prevalence (11.7% vs. 1.9%, P < 0.0001) and longer duration of esophageal examination (mean ± standard deviation, 17.50 ± 12.40 vs. 15.24 ± 10.78 seconds, P = 0.004) were noted in group I than in group II. Analyzing group I patients revealed the higher prevalences of reflux symptoms (32.7% vs. 18.3%, P = 0.013) and erosive esophagitis (43.6% vs. 25.5%, P = 0.005) in patients with CIP than in those without. CIP was not associated with globus or dysphagia symptoms. More small CIPs (< 5 mm) were detected by ME-NBI than by white-light imaging (85.3% vs. 41.4%, P = 0.001). In conclusion, CIP prevalence was not low under intentional ME-NBI examination of the upper esophagus. The clinical relevance of CIP and its association with GERD require further investigation.

Narrow band imaging facilitates detection of inlet patches in the cervical oesophagus

BACKGROUND

Proximal esophageal heterotopic gastric mucosa or so-called inlet patch in the cervical oesophagus is easily missed on endoscopic examination because of its localisation, usually just below the upper oesophageal sphincter. We evaluated the clinical use of narrow band imaging for detection of inlet patches.

METHODS

In this prospective, controlled observational study, 1407 subsequent patients underwent oesophagogastroduodenoscopy with or without narrow band imaging on withdrawal of the endoscope in the cervical oesophagus.

RESULTS

One endoscopist who was not aware of the prospective observation documented 6 (1.17%) cases of inlet patches in 515 oesophagogastroduodenoscopies compared to 4 cases out of 382 (1.05%) performed by the endoscopist who paid special attention to the presence of inlet patches but did not routinely apply narrow band imaging (OR 0.89, CI 95% 0.25-3.20, p=0.85). In comparison, 17 cases of inlet patches out of 510 (3.33%) were detected by the endoscopist who routinely applied narrow band imaging. The detection rate of proximal oesophageal heterotopic gastric mucosa using narrow band imaging was significantly higher compared to white light endoscopy only (OR 3.06, CI 95% 1.39-6.73, p=0.005).

CONCLUSIONS

Withdrawal of the endoscope from the cervical oesophagus using narrow band imaging increased the detection of inlet patches about three-fold compared to standard white light endoscopy.

Laparoscopic narrow-band imaging for the diagnosis of peritoneal metastasis in gastric cancer

BACKGROUND

Staging laparoscopy (SL) is often used to diagnose peritoneal metastasis in patients with advanced gastric cancer, but accurate detection of metastasis can be difficult. We evaluated the usefulness of laparoscopic narrow-band imaging (NBI) versus conventional laparoscopic white-light imaging (WLI) for the diagnosis of peritoneal metastasis.

METHODS

We excised 37 white nodules from the parietal peritoneum of 26 patients with gastric cancer and suspected peritoneal metastasis. The WLI and NBI findings were compared with the pathological findings. All the peritoneal lesions examined were observed as white nodules on WLI. Intranodular vessels were evaluated by WLI and NBI for (1) vessel dilatation, (2) vessel tortuousness, (3) vessel heterogeneity, and (4) brown spots.

RESULTS

Each individual abnormal finding had a diagnostic accuracy of less than 79 % with or without NBI. Detection of any one abnormal finding had a sensitivity, specificity, and accuracy of 47.8, 85.7, and 62.2 %, respectively, on WLI and 91.3, 71.4, and 83.8 %, respectively, on NBI, for detection of peritoneal metastasis. Detection of any one abnormal finding on NBI plus clear demarcation of the nodule on WLI had a sensitivity of 91.3 %, specificity of 92.9 %, and accuracy of 91.9 % for detection of peritoneal metastasis. Pathological examination showed that a brown spot detected on NBI correlated with dilated vessels around cancer cells. Vascular endothelial growth factor was expressed in 76.2 % of peritoneal metastases.

CONCLUSIONS

NBI was more sensitive for the detection of dilated vessels than WLI. NBI could be a useful tool for the diagnosis of peritoneal metastasis during SL.

Endoscopic diagnosis of early Barrett's neoplasia: perspectives for advanced endoscopic technology

Barrett's esophagus (BE) is a metaplastic condition that occurs secondary to gastroesophageal reflux disease. BE is also a precursor to esophageal adenocarcinoma, which, although still rare in Japan, is one of the most rapidly increasing cancers in Western countries. However, the prevalence of gastroesophageal reflux disease has increased significantly over the past few decades in Japan, possibly leading to an incremental rise in BE and the associated inherent risk of adenocarcinoma. Given the poor prognosis of advanced-stage Barrett's adenocarcinoma, endoscopic surveillance is recommended for subjects with BE to detect early neoplasias including dysplasia. However, endoscopic identification of dysplastic lesions is still not sufficiently reliable or subjective, making targeted therapy extremely difficult. Over the past few years, improvements in image resolution, image processing software, and optical filter technology have enabled identification of dysplasia and early cancer in BE patients. We retrieved as many studies on advanced endoscopic technologies in BE as possible from MEDLINE and PubMed. The present review focuses on the emergent clinically available technologies to provide an overview of the technologies, their practical applicability, current status, and future challenges.

Update on narrow band imaging in disorders of the upper gastrointestinal tract

With the ever-increasing concern regarding morbidity and mortality associated with diseases of the gastrointestinal tract, the importance of an effective and efficient diagnostic tool cannot be overstated. The standard of care currently is an examination using conventional white light endoscopy. This approach may occasionally overlook areas exhibiting a premalignant change. Numerous image-enhanced modalities have been recently introduced. Narrow band imaging (NBI) appears to be the most prominent of these and perhaps the most commonly used. Thepresent review will focus on some of the newer studies on NBI and its utility in the diagnosis of malignant, pre-malignant and chronic inflammatory conditions of the upper gastrointestinal tract.

High definition endoscopy and "narrow band imaging" in the diagnosis of gastroesophageal reflux disease

INTRODUCTION

The gastroesophageal reflux disease is a common condition in the western world but less than half of patients present endoscopic abnormalities, making a standard procedure unsuitable for diagnosis. High definition endoscopy coupled with narrow band imaging has shown potential for differentiation of lesions and possible biopsy, allowing early diagnosis and treatment.

METHODS

This review describes the principles of biotic and their influence in obtaining images with better definition of the vessels in the mucosa, through the narrow band imaging. Selected papers using it in patients with reflux disease and Barrett's esophagus are analyzed in several ways, highlighting the findings and limitations.

CONCLUSION

The meaning of the narrow band imaging in the endoscopic diagnosis of reflux disease will be defined by large scale studies, with different categories of patients, including assessment of symptoms and response to treatment.

Differential diagnosis of colorectal polyps with respect to similar capabilities of white light colonoscopy and narrow-band imaging

PURPOSE

The responses of polyps to light essentially determine the diagnostic capability of an endoscopy system in differentiating adenomas from hyperplastic polyps. Compared with white light colonoscopy (WLC), narrow-band imaging (NBI) is expected to improve the diagnostic capability. The diagnostic capabilities of WLC and NBI are evaluated and compared based on the polyp responses.

METHODS

The following WLC and NBI images were retrospectively reviewed and categorized: 195 images and polyps (89 WLC, 106 NBI) with the best visual quality were categorized in the best image group (BG), and 484 images of 242 polyps (both WLC and NBI) were categorized in the paired image group (PG). For each reflection of light used for WLC or NBI, the polyp responses were objectively expressed as reflection features. The reflection features were then used to establish a classification model for identifying adenomas. The diagnostic capability of reflection feature or classification model was measured by the area under the receiver operating characteristic curve (AUC).

RESULTS

In both image groups, the diverse and heterogeneous features of the polyp responses enabled accurate identification of adenomas, regardless of the light source used for WLC and NBI. For differential diagnosis of adenomas and hyperplastic polyps, the WLC and NBI did not significantly differ in BG (AUC, 0.905 and 0.922, respectively; P = 0.690) or in PG (AUC, 0.782 and 0. 769, respectively; P = 0.755).

CONCLUSIONS

Using WLC and NBI as classification models is effective in differential diagnosis of colorectal polyps and exhibited similar capabilities.

The role of narrow-band imaging in the management of non-muscle-invasive bladder cancer

Narrow-band imaging is a young optical enhancement technology for endoscopy. It is a filter to the standard white light which increases the contrast between underlying vasculature and epithelial strata of the mucosa, improving the detection of bladder cancer with particular regard to high grade, flat lesions. Narrow band imaging is absolutely safe, may be used any time during a procedure, either during office cystosopy or transurethral resection, and implies a minimal burden for the healthcare provider given the absence of a learning curve and the limited cost of the camera and light source. The ameliorated detection translates into an improved management of the disease and a lower recurrence risk in prospective randomized studies, suggesting the inclusion of the technology in daily clinical practice.

Novel serine/threonine kinase 11 gene mutations in Peutz-Jeghers syndrome patients and endoscopic management

AIM: To explore mutations in serine/threonine kinase 11 (STK11) gene in Peutz-Jeghers syndrome (PJS) with gastrointestinal (GI) hamartomatous polyps.

METHODS: Six Japanese PJS patients in 3 families were enrolled in this study. Each of the cases had hamartomatous polyposis in the gastrointestinal tract, including the small intestine, along with mucocutaneous hyperpigmentation. Narrow-band imaging (NBI)-magnification endoscopy was employed to detect microvascular and microsurface irregularities in the GI lesions. NBI magnification findings could be classified into three groups (type A, type B, or type C). Endoscopic polypectomy was performed using double-balloon enteroscopy or colonoscopy. Genomic DNA was extracted from a whole blood sample from each subject. All of the coding exons of STK11 gene, its boundary regions, and the promoter region containing the polymorphic regions were amplified by polymerase chain reaction, and direct sequencing was performed to assess the germline mutations.

RESULTS: NBI-magnification endoscopic observation could detect the abnormalities in microvessels and microsurface structures of GI polyps. Overall, we found 5 cases of type A and one case without the examination for the gastric polyps, while there were 4 cases of type B and 2 case of type A for the colorectal polyps. Seventy-nine small-bowel and 115 colorectal polyps over 27 sessions for each were resected endoscopically without significant complications. The only delayed complication included the occurrence of bleeding in a case, and this was successfully managed with hemoclips. Resected polyps contained no malignant components. Based on mutation analysis, all 3 cases in Family I exhibited the +658C>T nonsense mutation in exon 5, which resulted in the production of a truncated protein (Q220X). In Family II, a case had -252C>A and -193C>A in the promoter region. In Family III, a case was found to have the +1062C>G (F342L) mutation in exon 8.

CONCLUSION: We found two novel mutations of STK11 in association with PJS. Endoscopic polypectomy of GI polyps in PJS patients appears to be useful to prevent emergency laparotomies and reduce the cancer risk.

Narrow-band imaging without magnification for detecting early esophageal squamous cell carcinoma

AIM: To compare narrow-band imaging (NBI) without image magnification, and chromoendoscopy with Lugol’s solution for detecting high-grade dysplasia and intramucosal esophageal squamous cell carcinoma (SCC) in patients with head and neck cancer.

METHODS: This was a prospective observational study of 129 patients with primary head and neck tumors consecutively referred to the Gastrointestinal Endoscopy Unit of Hospital das Clínicas, São Paulo University Medical School, Brazil, between August 2006 and February 2007. Conventional examinations with NBI and Lugol chromoendoscopy were consecutively performed, and the discovered lesions were mapped, recorded and sent for biopsy. The results of the three methods were compared regarding sensitivity, specificity, accuracy, positive predictive value, negative predictive value, positive likelihood value and negative likelihood value.

RESULTS: Of the 129 patients, nine (7%) were diagnosed with SCC, 5 of which were in situ and 4 which were intramucosal. All carcinomas were detected through NBI and Lugol chromoendoscopy. Only 4 lesions were diagnosed through conventional examination, all of which were larger than 10 mm.

CONCLUSION: NBI technology with optical filters has high sensitivity and high negative predictive value for detecting superficial esophageal SCC, and produces results comparable to those obtained with 2.5% Lugol chromoendoscopy.

Autofluorescence imaging and magnification endoscopy

It is well known that angiogenesis is critical in the transition from premalignant to malignant lesions. Consequently, early detection and diagnosis based on morphological changes to the microvessels are crucial. In the last few years, new imaging techniques which utilize the properties of light-tissue interaction have been developed to increase early diagnosis of gastrointestinal (GI) tract neoplasia. We analyzed several “red-flag” endoscopic techniques used to enhance visualization of the vascular pattern of preneoplastic and neoplastic lesions (e.g. trimodal imaging including autofluorescence imaging, magnifying endoscopy and narrow band imaging). These new endoscopic techniques provide better visualization of mucosal microsurface structure and microvascular architecture and may enhance the diagnosis and characterization of mucosal lesions in the GI tract. In the near future, it is expected that trimodal imaging endoscopy will be practiced as a standard endoscopy technique as it is quick, safe and accurate for making a precise diagnosis of gastrointestinal pathology, with an emphasis on the diagnosis of early GI tract cancers. Further large-scale randomized controlled trials comparing these modalities in different patient subpopulations are warranted before their endorsement in the routine practice of GI endoscopy.

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.

Non-erosive reflux disease rather than cervical inlet patch involves globus

BACKGROUND

Gastroesophageal reflux is the most favored etiology for globus; however, recent studies suggest that a cervical inlet patch (heterotopic gastric mucosa in the cervical esophagus) involves globus. This study aimed to reveal whether these two conditions were associated with globus.

METHODS

A prospective cross-sectional survey was conducted for 2116 consecutive patients who underwent esophagogastroduodenoscopy in our hospital. Patients were interviewed about globus sensations and reflux symptoms prior to endoscopy. Non-erosive reflux disease was considered with reflux symptoms without reflux esophagitis. Inlet patch was detected using narrow-band imaging.

RESULTS

Sixty-three patients were excluded, and of the remaining 2053 patients (1117 male, 61 years old on average), 120 (5.8%) and 284 (13.8%) had globus and inlet patch, respectively. Multivariate analysis (n = 1584) following the exclusion of proton pump inhibitor users revealed that female gender, younger age (<60), inlet patch, and reflux symptoms were independent risk factors for the development of globus; however, reflux esophagitis was an independent factor for reducing the development of globus. In a reanalysis of non-erosive reflux disease instead of reflux symptoms, inlet patch and non-erosive reflux disease were independent risk factors for the development of globus (odds ratio, 2.9 and 12.1, respectively).

CONCLUSIONS

Non-erosive reflux disease was more closely associated with globus than an inlet patch. Our controversial results indicating a strong association of globus with non-erosive reflux disease and an inverse association of globus with reflux esophagitis may suggest that mechanisms other than gastroesophageal reflux as the etiology, such as an esophageal visceral hypersensitivity, involve globus.

Meshed capillary vessels found on narrow-band imaging without optical magnification effectively identifies colorectal neoplasia: a North American validation of the Japanese experience

BACKGROUND

The presence of meshed capillary (MC) vessels is highly sensitive (96%) and specific (92%) for diagnosing colorectal neoplasia on colonoscopy by using narrow-band imaging (NBI) with optical magnification, which is not available in North America. However, the efficacy of NBI to identify an MC pattern without optical magnification has not been determined.

OBJECTIVE

To determine the diagnostic capabilities of NBI colonoscopy without optical magnification in differentiating neoplastic from non-neoplastic colorectal polyps by using the MC pattern.

DESIGN

Retrospective comparison of prospectively collected colorectal polyp data.

SETTING

Large, academic medical center.

PATIENTS

This study involved 126 consecutive colorectal polyps (median size 3 mm) that were found in 52 patients (33 men) with a median age of 59.5 years.

INTERVENTION

All lesions identified by white-light colonoscopy were prospectively diagnosed in real-time by using the MC pattern as determined on high-definition NBI, with 1.5x zoom but without true optical magnification, and then endoscopically excised. Surgical pathology was used as the criterion standard.

MAIN OUTCOME MEASUREMENTS

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of identifying neoplastic polyps were calculated.

RESULTS

NBI without optical magnification was found to have a sensitivity of 93%, specificity of 88%, positive predictive value of 90%, negative predictive value of 91%, and diagnostic accuracy of 91% when all polyp sizes were considered. For lesions < or =5 mm, sensitivity was 87%, specificity was 93%, positive predictive value was 89%, negative predictive value was 91%, and diagnostic accuracy was 90%.

LIMITATIONS

Single-center, single-endoscopist experience.

CONCLUSION

Use of the MC pattern on NBI colonoscopy without optical magnification effectively distinguishes neoplastic from non-neoplastic colorectal polyps. NBI colonoscopy without optical magnification for neoplastic polyp diagnosis appears to be comparable with NBI with optical magnification when the MC pattern is used. A large, prospective trial is needed for further validation.

Narrow-band imaging in diagnosis of endometrial cancer and hyperplasia: a new option?

STUDY OBJECTIVE

To estimate whether the use of narrow-band imaging (NBI) hysteroscopy increases concordance between visual identification and a histologic diagnosis of endometrial cancer and hyperplasia.

DESIGN

Prospective study (Canadian Task Force classification: II-2).

SETTING

Department of obstetrics and gynecology, University of Eastern Piedmont, Novara, Italy.

PATIENTS

209 consecutive patients with abnormal uterine bleeding.

INTERVENTIONS

White-light hysteroscopy and NBI hysteroscopy followed by direct biopsy.

MEASUREMENTS AND MAIN RESULTS

The sensitivity and specificity of conventional hysteroscopy in predicting a diagnosis of cancer and hyperplasia were, respectively, 84.21% (95% confidence interval [CI], 79.27-89.15) and 99.47% (95% CI, 98.49-100.0), and 64.86% (95% CI, 58.39-71.34) and 98.77% (95% CI, 97.27-100.0), and of NBI hysteroscopy were 94.74% (95% CI, 91.71-97.76) and 97.89% (95% CI, 95.95-99.84), and 78.38% (95% CI, 72.8-83.96) and 97.67% (95% CI, 96.63-99.72). The concordance of conventional and NBI hysteroscopy with the histopathologic findings (measured using the Cohen kappa) was, respectively, 88.80% (95% CI, 86.2%-96.3%) and 91.78% (95% CI, 89.6%-98.2%), a difference of 2.98% (95% CI, 0-9) in favor of NBI.

CONCLUSION

Narrow-band imaging hysteroscopy can accurately predict a histologic diagnosis of endometrial cancer or hyperplasia.

Early detection of superficial squamous cell carcinoma in the head and neck region and esophagus by narrow band imaging: a multicenter randomized controlled trial

PURPOSE

Most of the esophageal squamous cell carcinomas (ESCCs) and cancers of the head and neck (H&N) region are diagnosed at later stages. To achieve better survival, early detection is necessary. We compared the real-time diagnostic yield of superficial cancer in these regions between conventional white light imaging (WLI) and narrow band imaging (NBI) in high-risk patients.

PATIENTS AND METHODS

In a multicenter, prospective, randomized controlled trial, 320 patients with ESCC were randomly assigned to primary WLI followed by NBI (n = 162) or primary NBI followed by WLI (n = 158) in a back-to-back fashion. The primary aim was to compare the real-time detection rates of superficial cancer in the H&N region and the esophagus between WLI and NBI. The secondary aim was to evaluate the diagnostic accuracy of these techniques.

RESULTS

NBI detected superficial cancer more frequently than did WLI in both the H&N region and the esophagus (100% v 8%, P < .001; 97% v 55%, P < .001, respectively). The sensitivity of NBI for diagnosis of superficial cancer was 100% and 97.2% in the H&N region and the esophagus, respectively. The accuracy of NBI for diagnosis of superficial cancer was 86.7% and 88.9% in these regions, respectively. The sensitivity and accuracy were significantly higher using NBI than WLI in both regions (P < .001 and P = .02 for the H&N region; P < .001 for both measures for the esophagus, respectively).

CONCLUSION

NBI could be the standard examination for the early detection of superficial cancer in the H&N region and the esophagus.