High magnification bronchovideoscopy combined with narrow band imaging could detect capillary loops of angiogenic squamous dysplasia in heavy smokers at high risk for lung cancer

Pulmonary squamous cell carcinoma and lymphoepithelial carcinoma - morphology, molecular characteristics and differential diagnosis

Squamous cell carcinoma (SCC) comprises one of the major groups of non-small-cell carcinoma of the lung, and is subtyped into keratinising, non-keratinising and basaloid SCC. SCC can readily be diagnosed using histomorphology alone in keratinising SCC. Confirmatory immunohistochemical analyses should always be applied in non-keratinising and basaloid tumours to exclude differential diagnoses, most prominently adenocarcinoma and high-grade neuroendocrine carcinoma, which may have important therapeutic consequences. According to the World Health Organisation (WHO) classification 2015, the diagnosis of SCC can be rendered in resections of morphologically ambiguous tumours with squamous immunophenotype. In biopsies and cytology preparations in the same setting the current guidelines propose a diagnosis of 'non-small-cell carcinoma, favour SCC' in TTF1-negative and p40-positive tumours to acknowledge a possible sampling bias and restrict extended immunohistochemical evaluation in order to preserve tissue for molecular testing. Most SCC feature a molecular 'tobacco-smoke signature' with enrichment in GG > TT mutations, in line with the strong epidemiological association of SCC with smoking. Targetable mutations are extremely rare but they do occur, in particular in younger and non- or light-smoking patients, warranting molecular investigations. Lymphoepithelial carcinoma (LEC) is a poorly differentiated SCC with a syncytial growth pattern and a usually prominent lymphoplasmacytic infiltrate and frequent Epstein-Barr virus (EBV) association. In this review, we describe the morphological and molecular characteristics of SCC and LEC and discuss the most pertinent differential diagnoses.

Utility of Narrow-band Imaging Bronchoscopy in the Diagnosis of Endobronchial Sarcoidosis

BACKGROUND

There are few reports on the utility of bronchoscopic narrow-band imaging (NBI) for visualizing endobronchial abnormalities in sarcoidosis. Our primary objective was to compare the sensitivity of finding endobronchial abnormality using NBI versus white light bronchoscopy (WLB) in patients with sarcoidosis. The secondary aim was to evaluate the sensitivity of NBI in diagnosing endobronchial sarcoidosis against a reference standard of positive endobronchial biopsy (EBB).

METHODS

We retrospectively included subjects with sarcoidosis, where we sequentially recorded WLB and NBI videos to visualize the endobronchial mucosa. We collected data on the demographic findings, sarcoidosis stage, and the histopathological findings of transbronchial needle aspiration, EBB, and transbronchial lung biopsy. Three experienced bronchoscopists viewed the video recordings and noted the abnormalities of the airway mucosa separately on WLB and NBI.

RESULTS

We included 28 subjects (mean age, 42.9 y; 53.6% men; 14 each, stages 1 and 2) with a final diagnosis of sarcoidosis. Granulomas were detected on EBB in 11 (39.3%) subjects. We identified endobronchial nodules in 10 and 15 subjects on WLB and NBI. The sensitivity of finding endobronchial abnormality using WLB and NBI was 35.7% (10/28) and 53.6% (15/28), respectively (χ 2 =1.77, df=1, P =0.18). The sensitivity of NBI in diagnosing endobronchial sarcoidosis against a positive EBB was 63.6% (7/11 subjects). There was excellent agreement (Κ=0.86) for detecting nodules on NBI among the 3 observers.

CONCLUSION

NBI might allow the identification of additional abnormalities not detected on WLB in sarcoidosis. Larger studies are required to confirm our observations.

A narrative review: narrow-band imaging endoscopic classifications

Background and Objective

With the development of endoscopic techniques, narrow-band imaging (NBI) has been widely used in the diagnosis of various types of diseases. NBI can detect mucosal lesions at an early stage and different classification strategies have been established to help clinicians in disease diagnosis. However, there is currently no consensus for the classification criteria. This report summarizes the current classifications of diseases using NBI, so as to provide a comprehensive understanding of the various manifestations of mucosal lesions under NBI, and to promote the development of more practical NBI classifications.

Methods

The PubMed database was searched for English language articles published between January 1994 and November 2021 using the keywords 'narrow band imaging', 'NBI', and 'classification'.

Key Content and Findings

We systematically summarized the NBI classifications and manifestations of different diseases. The morphology of the mucosa and vessels was used as the basis of most classifications. These classifications are mainly helpful to distinguish benign and malignant tumors and to detect early neoplastic lesions.

Conclusions

This review summarized existing NBI classifications for different systems. These classifications will be updated as the understanding of diseases increases and new optical techniques become available to better assist doctors in making clinical decisions.

The value of narrow-band imaging bronchoscopy in diagnosing central lung cancer

Aims

This research aimed to study the value of narrow-band imaging(NBI) in the diagnosis of central lung cancer.

Materials and methods

This study included 916 patients with clinical suspected of central lung cancer or follow-up of patients after curative lung cancer surgery. All of the patients were examined by Olympus Evis Lucera electronic bronchoscope system, any sites that were abnormal when viewed by white-light bronchoscopy (WLB) or NBI were biopsied, four to six biopsies were taken at each site of the abnormal region visualized as lesions, we record the endoscopic features of NBI and compared with histopathology results, to evaluate the diagnostic value of NBI for central lung cancer and the relationship between vascular patterns of NBI and histological types of lung cancer, and try to establish a multinomial logistic regression model for predicting the histological types of lung cancer. The biopsy specimens were examined by CD34 antibody through immunohistochemistry (IHC) method, CD34 marked microvessel density(MVD), compared the number of microvessels between benign and malignant diseases and the number between different histological types of lung cancer, to verify the results of NBI.

Results

NBI provided high sensitivity (91.7%), specificity (84.9%), positive predictive value (97.6%), negative predictive value (61.5%), and agreement rate (90.7%). The predominant vascular patterns in the well-defined histological types of lung cancer were dotted blood vessels (121 patients), tortuous blood vessels (248 patients), and abrupt-ending blood vessels (227 patients). Logistic regression analysis of the results showed that smoking status of the patient, combined with vascular patterns under NBI, and age partly affect the histological types of lung cancer.

Conclusions

NBI is highly accurate for the diagnosis of central lung cancer.

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.

NBI utility in oncologic surgery: An organ by organ review

The main aims of the oncologic surgeon should be an early tumor diagnosis, complete surgical resection, and a careful post-treatment follow-up to ensure a prompt diagnosis of recurrence. Radiologic and endoscopic methods have been traditionally used for these purposes, but their accuracy might sometimes be suboptimal. Technological improvements could help the clinician during the diagnostic and therapeutic management of tumors. Narrow band imaging (NBI) belongs to optical image techniques, and uses light characteristics to enhance tissue vascularization. Because neoangiogenesis is a fundamental step during carcinogenesis, NBI could be useful in the diagnostic and therapeutic workup of tumors. Since its introduction in 2001, NBI use has rapidly spread in different oncologic specialties with clear advantages. There is an active interest in this topic as demonstrated by the thriving literature. It is unavoidable for clinicians to gain in-depth knowledge about the application of NBI to their specific field, losing the overall view on the topic. However, by looking at other fields of application, clinicians could find ideas to improve NBI use in their own specialty. The aim of this review is to summarize the existing literature on NBI use in oncology, with the aim of providing the state of the art: we present an overview on NBI fields of application, results, and possible future improvements in the different specialties.

Application of Narrow-Band Imaging thoracoscopy in diagnosis of pleural diseases

BACKGROUND

Patients with undiagnostic pleural effusions are routinely examined by conventional medical thoracoscopy under the white light (WL). The endoscopic appearance of pleural diseases under WL could be misleading. Narrow-Band Imaging (NBI) has been applied as an interesting and effective diagnostic tool for endoscopy. However, there is also controversy about its value in the application of thoracoscopy.

OBJECTIVE

The objective of this study was to investigate the diagnostic value of NBI technology during thoracoscopy.

METHODS

Patients with undiagnosed pleural effusions admitted to our hospital between September 2017 and September 2019 were enrolled. During the thoracoscopy, we performed WL mode first and then NBI. Pictures of endoscopic real-time lesions were recorded under two modes, and at least five pieces of tissue were taken, respectively, on pleura lesions. Biopsy specimens were respectively taken for pathologic analysis. Diagnostic sensitivity, specificity were calculated to compare with pathologic results.

RESULTS

100 eligible patients were enrolled, including 63 with malignancy, 23 with tuberculous pleurisy, 3 with systemic disease and 11 with the negative condition. Compared with pathological results, the sensitivity of WL was 91.01%, and NBI 84.27%; while the specificity of WL was 27.27%, and NBI 81.82%. Compared NBI with WL, the former's specificity is superior to the latter's, which is statistically significant (P < 0.05).

CONCLUSIONS

The advantage of NBI lies in its high specificity. It's useful to diagnose unknown pleural effusions in clinical practice. With better visualization of blood vessels, we can enhance the accuracy of biopsy and reduce the risk of unexpected bleeding arose from the biopsy.

Intrathoracic amyloid tumors that presented as yellowish multinodular endobronchial protrusions with irregular vascularity and easy bleeding

Immunoglobulin light‐chain (AL) amyloidosis is a monoclonal plasma cell neoplasm that has a tendency to bleed easily. However, the potential risks of transbronchial biopsy in such cases have not been fully proven. Here, we report a case of parotid and intrathoracic AL amyloid tumors that presented as endobronchial protrusions that bled easily. Bronchoscopy under conventional white light and narrow band imaging revealed yellowish multinodular protrusions, in which irregular tortuous or dotted vessels were observed. Unexpectedly, biopsy of the lesion resulted in persistent bleeding. The biopsy specimen showed a large amount of amyloid deposition and calcification directly under the bronchial epithelium, as well as amyloid deposits in the blood vessel walls. In patients suspected to have amyloidosis, the presence of yellowish multinodular endobronchial protrusions, particularly with irregular vascularity, should prompt careful attention to avoid fatal postprocedural bleeding.

Bronchoscopic observation with linked colour imaging

We report two cases of the comparison of diagnosis made with linked color imaging (LCI) and conventional white-light imaging (WLI) on the same patients. In case 1, a 75-year-old man in whom right upper lobectomy with mediastinal lymph node dissection was performed due to lung cancer had signs of bronchitis on postoperative day 8. The LCI demonstrated slight inflammatory changes that were not detectable with the conventional WLI on the tracheal wall. In case 2, in a 61-year-old woman who was diagnosed with adenoid cystic carcinoma, the bronchial wall was checked to confirm the extent of the tumour. The submucosal vascularity and tumour margin on the bronchial mucosa were better visible on LCI than on WLI. We could easily detect the mucosal inflammatory lesion and the malignant lesion with LCI in comparison with conventional WLI. Both mucosal inflammatory and malignant lesions were better visible with LCI in comparison to WLI.

Advances in Interventional Pulmonology

Much has changed since the last review of interventional pulmonology (IP) published in this Clinics series. The rate of development of new techniques and their complexities require IP physicians to be constantly maintaining and updating their skill set. International agreed training pathways help ensure that the interventionalists of the present and future have the required knowledge of anatomy, manual dexterity, and clinical judgment to keep up with the continuing advances that are constantly expanding IP's diagnostic and therapeutic boundaries. IP remains one of the most desirable subspecialities in pulmonology, and the technologic advances make the future an exciting one.

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Use of Narrow Band Imaging in the Diagnosis of Hypovascular Endobronchial Sarcoidosis

Narrow band imaging (NBI) has been widely applied for the evaluation of numerous disease conditions that present with increased vascularity of the mucosa, most often malignancies. It is increasingly being used in benign conditions as well. We present the first case in which NBI was used, rather, to detect areas of bronchial hypovascularity due to its ability to increase the visual contrast between normal and hypovascular mucosa. Endobronchial biopsy of these nodules led to the diagnosis of sarcoidosis. Had conventional white light alone been utilized, the diagnosis would likely have been missed because not only were these lesions difficult to visualize under white light but transbronchial lung biopsy and transbronchial needle aspiration were unremarkable. We propose that NBI should be considered in the bronchoscopic evaluation of possible sarcoidosis or any other condition that could present with airway hypovascularity.

Image enhancement technology in bronchoscopy: a prospective multicentre study in lung cancer

Introduction

Patients with lung cancer may present with additional lesions in the central airways. Earlier studies have shown a relationship between vessel diameter, pattern and grade of malignancy. High-definition (HD+) bronchoscopy with image enhancement techniques (i-scan) detected more vascular abnormalities but correlation with pathology has not yet been established.

Methods

In this investigator-initiated, randomised, controlled, crossover, multicentre study in patients with suspected lung cancer, a HD+ bronchoscopy was performed with i-scan1 and i-scan2 settings in random order. Biopsies, visual grade and vascular pattern classification were obtained by endoscopists and blinded evaluation.

Results

In 107 patients, vascular patterns were classified in 48 tumours. Abrupt-ending vessels were predominantly found in squamous cell carcinoma but overall correlation between vessel pattern and histology was not significant (p=0.339). Additional lesions were detected in 35 patients (33%) with a correlation between vessel pattern and high-grade (pre-)invasive lesions (p<0.001). In 8.4% of the patients, relevant second lesions were detected which determined treatment and staging in 3% of all patients. Interobserver agreement was excellent for visual grading of the airway epithelium, but low for classifying vascular patterns. No significant detection rate difference was found by blinded and unblinded evaluation.

Conclusion

HD+ bronchoscopy with i-scan image enhancement readily detects additional lesions. In one-third of all the patients, additional lesions were detected. Their vascular pattern correlates to pathology outcome, but the interobserver correlation for vascular pattern classification is low. These lesions were relevant in 8.4% and affected treatment and work-up in 3% of the cases.

Trial registration number

NCT02285426; Results.

[Modern approaches to the diagnosis of precancerous pathology and early lung cancer]

AIM

To assess the possibilities of modern diagnostic techniques to diagnose precancerous pathology and early central lung cancer.

MATERIAL AND METHODS

Analysis of Russian and foreign publications for precancerous pathology and early lung cancer, results and comparison of various diagnostic techniques.

RESULTS

Central lung cancer has a stepwise development with transformation of normal bronchial epithelium to hyperplastic followed by focal metaplasia, dysplasia, cancer in situ (CIS) and microinvasive cancer. Fluorography, chest X-ray, computed tomography, magnetic resonance imaging and sputum cytology examination are used to diagnose lung cancer. However, endoscopy plays a leading role in diagnosis of early central lung cancer which rapidly and effectively detects changes of tracheobronchial tree mucosa at the initial stages of carcinogenesis thanks to the use of modern techniques (spectral, autofluorescent and ZOOM - endoscopy).

The technique of endoscopic airway tumor treatment

More than half of primary lung cancers are not resectable at diagnosis and 40% of deaths may be secondary to loco-regional disease. Many of these patients suffer from symptoms related to airways obstruction. Indications for therapeutic endoscopic treatment are palliation of dyspnea and other obstructive symptoms in advanced cancerous lesions and cure of early lung cancer. Bronchoscopic management is also indicated for all those patients suffering from benign or minimally invasive neoplasm who are not suitable for surgery due to their clinical conditions. Clinicians should select cases, evaluating tumor features (size, location) and patient characteristics (age, lung function impairment) to choose the most appropriate endoscopic technique. Laser therapy, electrocautery, cryotherapy and stenting are well-described techniques for the palliation of symptoms due to airway involvement and local treatment of endobronchial lesions. Newer technologies, with an established role in clinical practice, are endobronchial ultrasound (EBUS), autofluorescence bronchoscopy (AFB), and narrow band imaging (NBI). Other techniques, such as endobronchial intra-tumoral chemotherapy (EITC), EBUS-guided-transbronchial needle injection or bronchoscopy-guided radiofrequency ablation (RFA), are in development for the use within the airways. These endobronchial interventions are important adjuncts in the multimodality management of lung cancer and should become standard considerations in the management of patients with advanced lung cancer, benign or otherwise not approachable central airway lesions. We aimed at revising several endobronchial treatment modalities that can augment standard antitumor therapies for advanced lung cancer, including rigid and flexible bronchoscopy, laser therapy, endobronchial prosthesis, and photodynamic therapy (PDT).

The diagnostic value of narrow-band imaging for early and invasive lung cancer: a meta-analysis

This study aimed to compare the ability of narrow-band imaging to detect early and invasive lung cancer with that of conventional pathological analysis and white-light bronchoscopy. We searched the PubMed, EMBASE, Sinomed, and China National Knowledge Infrastructure databases for relevant studies. Meta-disc software was used to perform data analysis, meta-regression analysis, sensitivity analysis, and heterogeneity testing, and STATA software was used to determine if publication bias was present, as well as to calculate the relative risks for the sensitivity and specificity of narrow-band imaging vs those of white-light bronchoscopy for the detection of early and invasive lung cancer. A random-effects model was used to assess the diagnostic efficacy of the above modalities in cases in which a high degree of between-study heterogeneity was noted with respect to their diagnostic efficacies. The database search identified six studies including 578 patients. The pooled sensitivity and specificity of narrow-band imaging were 86% (95% confidence interval: 83-88%) and 81% (95% confidence interval: 77-84%), respectively, and the pooled sensitivity and specificity of white-light bronchoscopy were 70% (95% confidence interval: 66-74%) and 66% (95% confidence interval: 62-70%), respectively. The pooled relative risks for the sensitivity and specificity of narrow-band imaging vs the sensitivity and specificity of white-light bronchoscopy for the detection of early and invasive lung cancer were 1.33 (95% confidence interval: 1.07-1.67) and 1.09 (95% confidence interval: 0.84-1.42), respectively, and sensitivity analysis showed that narrow-band imaging exhibited good diagnostic efficacy with respect to detecting early and invasive lung cancer and that the results of the study were stable. Narrow-band imaging was superior to white light bronchoscopy with respect to detecting early and invasive lung cancer; however, the specificities of the two modalities did not differ significantly.

Hypoxia imaging and radiotherapy: bridging the resolution gap

Oxygen distribution is a major determinant of treatment success in radiotherapy, with well-oxygenated tumour regions responding by up to a factor of three relative to anoxic volumes. Conversely, tumour hypoxia is associated with treatment resistance and negative prognosis. Tumour oxygenation is highly heterogeneous and difficult to measure directly. The recent advent of functional hypoxia imaging modalities such as fluorine-18 fluoromisonidazole positron emission tomography have shown promise in non-invasively determining regions of low oxygen tension. This raises the prospect of selectively increasing dose to hypoxic subvolumes, a concept known as dose painting. Yet while this is a promising approach, oxygen-mediated radioresistance is inherently a multiscale problem, and there are still a number of substantial challenges that must be overcome if hypoxia dose painting is to be successfully implemented. Current imaging modalities are limited by the physics of such systems to have resolutions in the millimetre regime, whereas oxygen distribution varies over a micron scale, and treatment delivery is typically modulated on a centimetre scale. In this review, we examine the mechanistic basis and implications of the radiobiological oxygen effect, the factors influencing microscopic heterogeneity in tumour oxygenation and the consequent challenges in the interpretation of clinical hypoxia imaging (in particular fluorine-18 fluoromisonidazole positron emission tomography). We also discuss dose-painting approaches and outline challenges that must be addressed to improve this treatment paradigm.

Dual red imaging (novel advanced endoscopy) can increase visibility and can predict the depth in diagnosing esophageal varices

BACKGROUND

Dual red imaging (DRI) is a new technology that can increase the visibility of deeper veins compared with narrow band imaging (NBI). As esophageal varices (EVs) are a vascular disease occurring in the submucosal layer, their visibility might be increased by DRI. We prospectively clarified whether the visibility of EVs with red color sign (RCS) can be increased by DRI, and clarified the relation between the visibility scores and the obtained endoscopic ultrasound (EUS) images.

METHODS

Forty patients were enrolled. The visibility of the EVs on DRI and NBI endoscopic images was evaluated by five observers in a blinded manner and was compared with a white light image (bad, 0; equal, 1; good, 2). The diameter of the lumen and the depth of the EVs and RCS from the epithelium were measured by EUS. The relation between the visibility scores and the EUS findings was investigated.

RESULTS

The DRI scores were 1.66 ± 0.34 for the EV substance and 1.79 ± 0.28 for the RCS, whereas the NBI scores were 0.68 ± 0.38 and 0.41 ± 0.28, respectively. A significant negative correlation was found between the depth and the visibility score (r = -0.505, p = 0.001 for EVs; r = -0.458, p = 0.003 for RCS).

CONCLUSIONS

DRI increased the visibility of the EVs and RCS. The visibility of the EVs or RCS in the shallower position was more enhanced by DRI. Visual recognition of the changing degrees of visibility by DRI enables the prediction of the depth of EVs.

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.

The role of bronchoscopy in the diagnosis of early lung cancer: a review

Lung cancer is the leading cause of cancer-related deaths worldwide with an overall 5-year survival rate of 17% after diagnoses. Indeed many patients tend to have a very poor prognosis, due to being diagnosed at an advanced stage. Conversely patients who are diagnosed at an early stage have a 5-year survival >70%, indicating that early detection of lung cancer is crucial to improve survival. Although flexible bronchoscopy is a relatively non-invasive procedure for patients suspected of having lung cancer, only 29% of carcinoma in situ (CIS) and 69% of microinvasive tumors were detectable using white light bronchoscopy (WLB) alone. As a result, in the past two decades, new bronchoscopic techniques have been developed to increase the yield and diagnostic accuracy, such as autofluorescence bronchoscopy (AFB), narrow band imaging (NBI) and high magnification bronchovideoscopy (HMB). However, due to the low specificity and the limitation to detect only proximal bronchial tree, new probe-based technologies have been introduced: radial endobronchial ultrasound (R-EBUS), optical coherence tomography (OCT), confocal laser endomicroscopy (CLE) and laser Raman spectroscopy (LRS). To date, although tissue biopsy remains the gold standard for diagnosing malignant/premalignant airway disease and some techniques are still investigational, bronchoscopic technologies can be considered the safest and most accurate tools to evaluate both central and distal airway mucosa.

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.

The clinical diagnostic value of target biopsy using narrow-band imaging endoscopy and accurate laryngeal carcinoma pathologic specimen acquisition

OBJECTIVE

To estimate the clinical significance of target biopsy for clinical diagnosis and determine accurate laryngeal lesion pathologic specimen acquisition via narrow-band imaging (NBI) endoscopy.

METHODS

A total of 138 samples from patients with laryngeal lesions (carcinoma, 118; hyperplasia, 3; mild dysplasia, 2; moderate dysplasia, 5; severe dysplasia, 5; vocal cord polyp, 1; and inflammatory lesion, 4) were collected from the Department of Otolaryngology Head and Neck Surgery of Tianjin Union Medical Center from 1 January 2013 to 1 February 2015. All patients were divided into the regular biopsy and NBI target biopsy groups; the imaging data were recorded and patient samples were biopsied. Pathologic diagnoses were used to evaluate the accuracies of regular and target biopsy.

RESULTS

Based on the pathologic diagnosis, NBI target pathology yielded an accurate laryngeal lesion pathologic specimen acquisition rate of 95.6% (65/68), significantly higher than that yielded by regular biopsy (75.7%, 53/70; χ² = 10.99, P = 0.001). In the NBI target pathology group, the correct accurate pathologic specimen acquisition rates at laryngeal cancer diagnostic stages 0 (Tis), I and II were 100%, 100% and 85.71%, respectively, which were higher than the corresponding rates in the regular biopsy group (0%, χ² = 10.000, P = 0.002; 25%, χ² = 5.625, P = 0.018; and 38.46%, χ² = 6.454, P = 0.011, respectively).

CONCLUSIONS

In cases of laryngeal carcinoma, NBI endoscopy plays an important role in clinical diagnosis and accurate pathologic specimen acquisition and could be a regular clinical method for laryngeal lesion detection.

Distinguishing Bronchoscopic Changes of Mitral Stenosis From Carcinoma In Situ With Narrow Band Imaging

A 75-year-old woman presented with minor hemoptysis. Past history included atrial fibrillation and rheumatic mitral stenosis. Bronchoscopy revealed a striking abnormality of widespread dilated mucosal and submucosal vessels. Initially the concern was whether there was widespread endobronchial malignancy; however, narrow band imaging (NBI) demonstrated the symmetrical uniform nature of the vessels. In addition, there was a focal area of in situ carcinoma with classic NBI features of malignancy. Following external-beam radiation therapy, NBI features had dramatically changed in the treated area which was now biopsy negative. The case highlights the utility of NBI in identifying endobronchial microvessel appearance even where there are widespread nonmalignant vessel changes in the bronchial mucosa.

[Narrow band imaging for early diagnosis of epithelial dysplasias and microinvasive tumors in the upper aerodigestive tract]

The various stages of tumor growth are characterized by typical epithelial, vascular, and secondary connective tissue changes. Narrow band imaging (NBI) endoscopy is a minimally invasive imaging technique that presents vascular structures in particular at a higher contrast than white light endoscopy alone. In combination with high-resolution image recording and reproduction (high-definition television, HDTV; ultra-high definition, 4K), progress has been made in otolaryngological differential diagnostics, both pre- and intraoperatively. This progress represents an important step towards a so-called optical biopsy. Flexible endoscopy in combination with NBI allows detailed assessment of areas of the upper aerodigestive tract which are difficult to assess by rigid endoscopy. Papillomas, precancerous, and cancerous lesions are characterized by epithelial and connective tissue changes, as well as by typical perpendicular vascular changes. Systematic use of NBI is recommended in the differential diagnosis of malignant lesions of the upper aerodigestive tract. NBI also convinces by a significant improvement in pre- and intraoperative assessment of superficial resection margins. In particular, the combination of NBI and contact endoscopy (compact endoscopy) permits excellent therapeutic decisions during tumor surgery. Intraoperative determination of resection margins at unprecedented precision is possible. In addition, assessment of the form and extent of the perpendicular vessel loops stimulated by epithelial signaling enables differential diagnostic decisions to be made, approximating our goal of an optical biopsy.

Advances in diagnostic interventional pulmonology

The recent advances in diagnostic pulmonary procedures have revolutionized the evaluation of abnormal thoracic findings including lung nodules and masses, mediastinal lymphadenopathy, and pleural diseases. Bronchoscopies with endobronchial ultrasonography and electromagnetic navigation are examples of new technology that has significantly improved the specificity and sensitivity of these procedures in diagnosis and staging of lung cancer without the need for more invasive procedures. This report describes the different diagnostic pulmonary interventions providing a description of the procedures, their indications, diagnostic yield and drawback.

Narrow-band imaging bronchoscopy in the detection of premalignant airway lesions: a meta-analysis of diagnostic test accuracy

OBJECTIVES

Both autofluorescence imaging bronchoscopy and narrow-band imaging have shown promise in the detection of premalignant airway lesions, each by utilizing different bandwidths of lights for better characterization of the mucosal and submucosal vascular grid. Since previously published meta-analyses have shown poor specificity of autofluorescence imaging bronchoscopy, we specifically studied the diagnostic accuracy of narrow-band imaging alone and in combination with autofluorescence imaging bronchoscopy in the detection of premalignant airway lesions.

METHODS

After an extensive search of eligible studies from PubMed and Medline, extracted data were pooled with weighted averages. Symmetrical summary-receiver operating characteristic curves were constructed to summarize the results quantitatively. Study heterogeneity was assessed by the I(2) index.

RESULTS

Analysis of data from eight studies on narrow-band imaging showed a pooled sensitivity of 0.80 [95% confidence interval (CI): 0.77-0.83] and a pooled specificity of 0.84 (95% CI: 0.81-0.86). Summary-receiver operating characteristic curves from the data on narrow-band imaging calculated an area-under-the-curve of 0.908 (standard error 0.01). The diagnostic odds ratio of narrow-band imaging was 31.49 (95% CI: 12.17-81.45). Data from studies where narrow-band imaging and autofluorescence imaging bronchoscopy were used together showed a pooled sensitivity, specificity, area-under-the-curve and diagnostic odds ratios of 0.86 (95% CI: 0.82-0.89), 0.75 (95% CI: 0.71-0.79), 0.964 (standard error 0.05) and 27.96 (95% CI: 3.04-257.21), respectively.

CONCLUSIONS

Our findings indicate that in the evaluation of premalignant airway lesions, narrow-band imaging has a higher sensitivity, specificity and diagnostic odds ratios compared with autofluorescence imaging bronchoscopy. However, combining autofluorescence imaging bronchoscopy and narrow-band imaging does not significantly improve test performance characteristics.

High definition bronchoscopy: a randomized exploratory study of diagnostic value compared to standard white light bronchoscopy and autofluorescence bronchoscopy

Background

Videobronchoscopy is an essential diagnostic procedure for evaluation of the central airways and pivotal for the diagnosis and staging of lung cancer. Technological improvements have resulted in high definition (HD) images with advanced real time image enhancement techniques (i-scan).

Objectives

In this study we aimed to explore the sensitivity of HD+ i-scan bronchoscopy for detection of epithelial changes like vascular abnormalities and suspicious preinvasive lesions, and tumors.

Methods

In patients scheduled for a therapeutic or diagnostic procedure under general anesthesia videos of the bronchial tree were made using 5 videobronchoscopy modes in random order: normal white light videobronchoscopy (WLB), HD-bronchoscopy (HD), HD bronchoscopy with surface enhancement technique (i-scan1), HD with surface- and tone enhancement technique (i-scan2) and dual mode autofluorescence videobronchoscopy (AFB). The videos were scored in random order by two independent and blinded expert bronchoscopists.

Results

In 29 patients all videos were available for analysis. Vascular abnormalities were scored most frequently in HD + i-scan2 bronchoscopy (1.33 ± 0.29 abnormal or suspicious sites per patient) as compared to 0.12 ± 0.05 site for AFB (P = 0.003). Sites suspicious for preinvasive lesions were most frequently reported using AFB (0.74 ± 0.12 sites per patient) as compared to 0.17 ± 0.06 for both WLB and HD bronchoscopy (P = 0.003). Tumors were detected equally by all modalities. The preferred modality was HD bronchoscopy with i-scan (tone- plus surface and surface enhancement in respectively 38% and 35% of cases P = 0.006).

Conclusions

This study shows that high definition bronchoscopy with image enhancement technique may result in better detection of subtle vascular abnormalities in the airways. Since these abnormalities may be related to preneoplastic lesions and tumors this is of clinical relevance. Further investigations using this technique relating imaging to histology are warranted.

Advanced bronchoscopic techniques in diagnosis and staging of lung cancer

The role of advanced brochoscopic diagnostic techniques in detection and staging of lung cancer has steeply increased in recent years. Bronchoscopic imaging techniques became widely available and easy to use. Technical improvement led to merging in technologies making autofluorescence or narrow band imaging incorporated into one bronchoscope. New tools, such as autofluorescence imagining (AFI), narrow band imaging (NBI) or fuji intelligent chromo endoscopy (FICE), found their place in respiratory endoscopy suites. Development of endobronchial ultrasound (EBUS) improved minimally invasive mediastinal staging and diagnosis of peripheral lung lesions. Linear EBUS proven to be complementary to mediastinoscopy. This technique is now available in almost all high volume centers performing bronchoscopy. Radial EBUS with mini-probes and guiding sheaths provides accurate diagnosis of peripheral pulmonary lesions. Combining EBUS guided procedures with rapid on site cytology (ROSE) increases diagnostic yield even more. Electromagnetic navigation technology (EMN) is also widely used for diagnosis of peripheral lesions. Future development will certainly lead to new improvements in technology and creation of new sophisticated tools for research in respiratory endoscopy. Broncho-microscopy, alveoloscopy, optical coherence tomography are some of the new research techniques emerging for rapid technological development.

Diagnostic bronchoscopy--current and future perspectives

Lung cancer is the leading cause of cancer-related mortality worldwide. Standard bronchoscopy has limited ability to accurately localise and biopsy pulmonary lesions that cannot be directly visualised. The field of advanced diagnostic bronchoscopy is rapidly evolving due to advances in electronics and miniaturisation. Bronchoscopes with smaller outer working diameters, coupled with miniature radial and convex ultrasound probes, allow accurate central and peripheral pulmonary lesion localisation and biopsy while at the same time avoiding vascular structures. Increases in computational processing power allow three-dimensional reconstruction of computed tomographic raw data to enable virtual bronchoscopy (VB), providing the bronchoscopist with a preview of the bronchoscopy prior to the procedure. Navigational bronchoscopy enables targeting of peripheral pulmonary lesions (PPLs) via a "roadmap", similar to in-car global positioning systems. Analysis of lesions on a cellular level is now possible with techniques such as optical coherence tomography (OCT) and confocal microscopy (CM). All these tools will hopefully allow earlier and safer lung cancer diagnosis and in turn better patient outcomes. This article describes these new bronchoscopic techniques and reviews the relevant literature.

Effectiveness of narrow band imaging in the detection of premalignant and malignant lesions of the larynx: validation of a new endoscopic clinical classification

BACKGROUND

The purpose of this study was to assess the value of narrow band imaging (NBI) endoscopy in the diagnosis of pharyngolaryngeal lesions and to demonstrate the validity of a new NBI-based classification of their vascular pattern.

METHODS

From 2009 to 2011, 248 patients with pharyngolaryngeal lesions underwent NBI-endoscopic evaluation. NBI findings were classified into 5 types according to the Ni classification and were compared with histopathological reports. Sensitivity, specificity, accuracy, and positive predictive value (PPV) and negative predictive value (NPV) were calculated.

RESULTS

Sensitivity, specificity, accuracy, PPV, and NPV were 97.4%, 84.6%, 92.7%, 91.6%, and 95.1%, respectively. Ninety-eight percent of histologically malignant lesions corresponded to type V endoscopic pattern, whereas 84.8% of the non-neoplastic lesions corresponded to a type I to IV pattern.

CONCLUSION

The NBI ability to detect changes in the mucosal microvasculature can be useful for distinguishing nonmalignant from malignant lesions. An internationally accepted NBI-endoscopic classification may contribute to the further definition of the diagnostic validity of this technique.

Diagnosis and treatment of bronchial intraepithelial neoplasia and early lung cancer of the central airways: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Bronchial intraepithelial lesions may be precursors of central airway lung carcinomas. Identification and early treatment of these preinvasive lesions might prevent progression to invasive carcinoma.

METHODS

We systematically reviewed the literature to develop evidence-based recommendations regarding the diagnosis and treatment of intraepithelial lesions.

RESULTS

The risk and timeline for progression of bronchial intraepithelial lesions to carcinoma in situ (CIS) or invasive carcinoma are not well understood. Multiple studies show that autofluorescence bronchoscopy (AFB) is more sensitive that white light bronchoscopy (WLB) to identify these lesions. In patients with severe dysplasia or CIS in sputum cytology who have chest imaging studies showing no localizing abnormality, we suggest use of WLB; AFB may be used as an adjunct when available. Patients with known severe dysplasia or CIS of central airways should be followed with WLB or AFB, when available. WLB or AFB is also suggested for patients with early lung cancer who will undergo resection for delineation of tumor margins and assessment of synchronous lesions. However, AFB is not recommended prior to endobronchial therapy for CIS or early central lung cancer. Several endobronchial techniques are recommended for the treatment of patients with superficial limited mucosal lung cancer who are not candidates for resection.

CONCLUSION

Additional information is needed about the natural history and rate of progression of preinvasive central airway lesions. Patients with severe dysplasia or CIS may be treated endobronchially; however, it remains unclear if these therapies are associated with improved patient outcomes.

Detection and minimally invasive treatment of early squamous lung cancer

Non-small cell lung cancer (NSCLC) is the most common cause of cancer deaths worldwide. The majority of patents presenting with NSCLC have advanced disease, which precludes curative treatment. Early detection and treatment might result in the identification of more patients with early central lung cancer and improve survival. In addition, the study of early lung cancer improves understanding of lung carcinogenesis and might also reveal new treatment targets for advanced lung cancer. Bronchoscopic investigation of the central airways can reveal both early central lung cancer in situ (stage 0) and other preinvasive lesions such as dysplasia. In the current review we discuss the detection of early squamous lung cancer, the natural history of preinvasive lesions and whether biomarkers can be used to predict progression to cancer. Finally we will review the staging and management of preinvasive lung cancer lesions and the different therapeutic modalities that are available.

Confocal laser endomicroscopy reliably detects sepsis-related and treatment-associated changes in intestinal mucosal microcirculation

BACKGROUND

Microcirculatory alterations play a central role in the pathophysiology of sepsis. We investigated probe-based confocal laser endomicroscopy (pCLE) to assess alterations in mucosal microcirculatory perfusion in vivo in a porcine model of septic shock and in patients fulfilling consensus criteria for severe sepsis.

METHODS

Septic shock was induced using a faecal peritonitis model in anaesthetized, mechanically ventilated pigs. Mucosal microcirculation was assessed using pCLE in the stomach, duodenum, terminal ileum, and rectum. Duodenal microcirculation was further evaluated in 10 patients with severe sepsis and in 8 healthy controls to quantify capillary diameter, capillary length, and functional capillary density (FCD).

RESULTS

In the animal model, FCD was markedly decreased in duodenal (P<0.001), ileal (P<0.001), gastric (P<0.001), and rectal mucosa (P<0.005) 4 h after induction of sepsis. After volume therapy, FCD partially recovered to 90.0% (duodenum), 94.4% (ileum), 95.4% (gastric), and 97% (rectum) of baseline values, indicating decoupling of microvascular and macrovascular flow. In septic patients, the mean capillary diameter (P<0.01) and FCD (P<0.05) in duodenal mucosa were decreased compared with healthy controls.

CONCLUSIONS

pCLE reliably detected and quantified microcirculatory alterations in the gastrointestinal mucosa in a porcine model of sepsis and in patients with severe sepsis. Our data suggest that pCLE is a promising tool to assess the efficacy of therapeutic interventions on mucosal microcirculation in real-time, even in the clinical context.

[Combination of narrow-band imaging and autofluorescence imaging videobronchoscopy in the assessment of lung cancer]

背景与目的

窄带成像（narrow-band imaging, NBI）与自荧光成像（autofluorescence imaging, AFI）是近几年临床诊断肺癌的支气管镜新技术。本研究旨在研究这两种技术的结合是否能提高肺癌诊断的敏感性和特异性。

方法

该项目共纳入137例疑似肺癌患者，所有患者的检查均基于Olympus Evis Lucera电子支气管镜系统，依次进行白光支气管镜（white light bronchoscopy, WLB）、窄带成像、自荧光成像检查，在每位患者镜下异常部位至少取3块组织送检。

结果

WLB的敏感性、特异性分别为56.6%和62.5%；NBI成像的敏感性、特异性分别为71.3%和75.0%；AFI敏感性、特异性分别为82.2%和25.0%；NBI联合AFI的敏感性、特异性分别为94.6%和87.5%。NBI+AFI与AFI相比，两者敏感性及特异性均有统计学差异（P < 0.01），与单用NBI相比，两者敏感性及特异性亦有统计学差异（P < 0.05）。

结论

NBI或AFI比WLB在肺癌诊断方面具有更好的敏感性，且联合使用NBI+AFI比其它任何一种单用技术具有更高的敏感性和特异性优势。

Early lung cancer: methods for detection

Early detection and surgical resection are essential for the treatment of lung cancer. It would be ideal to be able to detect and treat preinvasive bronchial lesions, defined as dysplasia and carcinoma in situ before progressing to invasive cancer. Advanced airway-assessment techniques have opened an avenue for early detection and surveillance of endobronchial malignancy. This article reviews currently available advanced imaging techniques for early detection of lung cancer, including autofluorescence bronchoscopy, narrow-band imaging, high-magnification bronchovideoscopy, endobronchial ultrasonography, and optical coherence tomography. Also discussed are the more recently developed endocytoscopy system and confocal fluorescence microendoscopy, currently used only for research purposes.

Clinical evaluation and feasibility of changing intraoperative visibility with a novel viewing filter system for human eye

PURPOSE

The study was conducted to develop a new viewing system as a clinical prototype that enables visibility during surgery.

METHODS

The system was composed of several filters attached to the microscope. This nonrandomized, retrospective, observational case series study involved 33 eyes from 32 patients who presented with various diseases and underwent surgery. The authors evaluated the changes in visualization focusing on controlling intraoperative visibility under air infusion and enhancing Brilliant Blue G staining focusing a sharp-cut filter Y (SCY). Visibility was compared under various surgical conditions, including cataract surgery, both with and without this system. Quantitative analysis of changes in intraoperative reflection including halation under air infusion and Brilliant Blue G intensity was carried out using the International Commission on Illumination 1976 (L*, a*, b*) color space method.

RESULTS

A SCY reduced the reflection and halation by a maximum of 69.6%, when compared with use of no filter under air infusion (P < 0.01). The color difference between Brilliant Blue G-stained and nonstained areas was improved by 127.8% relative to values with no filter and using SCY (P < 0.01) in macular hole cases. Furthermore, in cataract surgery with corneal opacity, improvement of visibility was observed by SCY insertion.

CONCLUSION

The system improved intraoperative visibility under air infusion and the Brilliant Blue G staining intensity by use of SCY during vitrectomy.