Magnified endoscopy combined with narrow band imaging of minimal superficial esophageal neoplasia-indicators to differentiate intraepithelial neoplasias

Current Status of Mucosal Imaging with Narrow-Band Imaging in the Esophagus

Recent advances in endoscopic imaging of the esophagus have revolutionized the diagnostic capability for detecting premalignant changes and early esophageal malignancy. In this article, we review the practical application of narrow-band imaging focusing on diseases of the esophagus, including Barrett's esophagus, adenocarcinoma, and squamous cell carcinoma.

Diagnostic efficacy of dual-focus endoscopy with narrow-band imaging using simplified dyad criteria for superficial esophageal squamous cell carcinoma

BACKGROUND

Our previous studies have shown the diagnostic utility of a newly developed dual-focus endoscope with narrow-band imaging (DF-NBI) and simplified dyad criteria for detection of superficial esophageal squamous cell carcinoma (SESCC). This clinical trial aimed to study the diagnostic efficacy of DF-NBI with dyad criteria for detecting SESCC compared to white light imaging (WLI).

METHODS

This was a single-arm prospective comparative trial. We enrolled 170 consecutive high-risk patients for esophageal squamous cell carcinoma. Patients were initially examined with WLI by one independent endoscopist and then the other performed DF-NBI blinded to the WLI diagnosis to avoid a carry-over effect. Lesions showing proliferation and/or various shapes of intrapapillary capillary loops (IPCL) under DF-NBI (i.e., dyad criteria) were endoscopically diagnosed as SESCC including high-grade intraepithelial neoplasia. The primary endpoint was sensitivity of WLI and DF-NBI for detecting SESCC. The secondary endpoints were the diagnostic performance (i.e., specificity and accuracy) and inter/intra-observer concordance of DF-NBI with dyad criteria.

RESULTS

A total 77 SESCCs were detected. The sensitivity of DF-NBI for SESCC was significantly higher than that of WLI (91% vs. 51%, P < 0.001). The specificity and accuracy of WLI and DF-NBI using dyad criteria were 100% vs. 84%, and 86% vs. 86%, respectively. Various shapes and proliferation of IPCL showed the highest value in inter-observer and intra-observer agreements (κ = 0.77 and 0.82, respectively).

CONCLUSION

DF-NBI combined with dyad criteria may be a promising technique with a high sensitivity for diagnosis of SESCC and high inter/intra-observer agreement.

Endoscopic submucosal dissection and endoscopic mucosal resection for early stage esophageal cancer

Mortality from esophageal cancer remains high despite advances in medical therapy. Although the incidence of squamous cell carcinoma of the esophagus remains unchanged, the incidence of the esophageal adenocarcinoma has increased over time. Gastroesophageal reflux disease (GERD and obesity are contributing factors to the development of Barrett's esophagus and subsequent development of adenocarcinoma. Early recognition of the disease can lead to resection of esophageal cancer prior to the development of lymphovascular invasion. Various modalities have been implemented to aid identification of precancerous lesions and early esophageal cancer. Chromoendoscopy, narrowband imaging and endoscopic ultrasound examination are typically used for evaluating early esophageal lesions. Recently, confocal laser endomicroscopy (CLE) and volumetric laser scanning were implemented with promising results. Endoscopic management of early esophageal cancer may be done using endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). Both techniques allow resection of the mucosa (and possibly a portion of the submucosa) containing the early tumor without interruption of deeper layers. A submucosal injection creating a cushion coupled with snare resection or cap assisted mucosal suction followed by ligation and snare resection are the most common techniques of EMR. EMR can remove lesions less than 2 cm in size en bloc. Larger lesions may require resection in piecemeal fashion. This may limit assessment of the margins of the lesion and orienting the lesion's border. ESD offers en bloc dissection of the lesion regardless of its size. ESD is performed with specialized needle knives, which allow incision followed by careful dissection of the lesion within the submucosal layer. Tumor recurrence after ESD is rare but the technique is labor intensive and has an increased risk of perforation. Esophageal stenosis remains a concern after extensive EMR or ESD. Dilation with balloon or stent placement is usually sufficient to treat post-resection stenosis.

Simplified criteria for diagnosing superficial esophageal squamous neoplasms using Narrow Band Imaging magnifying endoscopy

AIM

To simplify the diagnostic criteria for superficial esophageal squamous cell carcinoma (SESCC) on Narrow Band Imaging combined with magnifying endoscopy (NBI-ME).

METHODS

This study was based on the post-hoc analysis of a randomized controlled trial. We performed NBI-ME for 147 patients with present or a history of squamous cell carcinoma in the head and neck, or esophagus between January 2009 and June 2011. Two expert endoscopists detected 89 lesions that were suspicious for SESCC lesions, which had been prospectively evaluated for the following 6 NBI-ME findings in real time: “intervascular background coloration”; “proliferation of intrapapillary capillary loops (IPCL)”; and “dilation”, “tortuosity”, “change in caliber”, and “various shapes (VS)” of IPCLs (i.e., Inoue’s tetrad criteria). The histologic examination of specimens was defined as the gold standard for diagnosis. A stepwise logistic regression analysis was used to identify candidates for the simplified criteria from among the 6 NBI-ME findings for diagnosing SESCCs. We evaluated diagnostic performance of the simplified criteria compared with that of Inoue’s criteria.

RESULTS

Fifty-four lesions (65%) were histologically diagnosed as SESCCs and the others as low-grade intraepithelial neoplasia or inflammation. In the univariate analysis, proliferation, tortuosity, change in caliber, and VS were significantly associated with SESCC (P < 0.01). The combination of VS and proliferation was statistically extracted from the 6 NBI-ME findings by using the stepwise logistic regression model. We defined the combination of VS and proliferation as simplified dyad criteria for SESCC. The areas under the curve of the simplified dyad criteria and Inoue’s tetrad criteria were 0.70 and 0.73, respectively. No significant difference was shown between them. The sensitivity, specificity, and accuracy of diagnosis for SESCC were 77.8%, 57.1%, 69.7% and 51.9%, 80.0%, 62.9% for the simplified dyad criteria and Inoue’s tetrad criteria, respectively.

CONCLUSION

The combination of proliferation and VS may serve as simplified criteria for the diagnosis of SESCC using NBI-ME.

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.