Contact endoscopy during microlaryngeal surgery: a new technique for endoscopic examination of the larynx

Contact Endoscopic Surface Vascular and Epithelial Morphology in Leukoplakia and Carcinoma of the Vocal Cords: Vascular and morphological changes of vocal folds in leukoplakia and cancer

Purpose Leukoplakia is a macroscopic morphological term for thick white or grey mucosal patches that can represent various histologic diagnostic entities ranging from hyperplasia to malignancy. Aim was the study morphology of the superficial mucosa and microvascular network of the vocal cords in patients with suspected glottic squamous cell carcinoma (SCC) using contact endoscopy (CE). Material and Methods Seventy-nine patients (21 female, 58 male), with a mean age of 57.5 years ± 7.12 (range, 32-73 years), were prospectively enrolled and evaluated. Of these patients, 58 had leukoplakia (Group A/41 males and 17 females, with a mean age of 53.7 years ± 6.65), and 21 (Group B/ 17males and 4 females/ with a mean age of 60.5 years ± 6.04) had malignant lesions (pT1, n = 6; p T2, n = 8; pT3, n = 8; Group B), as proven by the results of the histological examination. Further, 79 non-smokers (control group-group C) were studied. CE imaging findings were classified into five types (I to V) based on the features of the mucosal intra-epithelial capillary loops. CE findings were correlated to the histologic findings. A separate analysis involving smoking status was done. Results The CE-based intraepithelial papillary capillary loop classification score was strongly correlated with the histological findings. Age was strongly associated with both malignancy and bilateral involvement. Smoking habits didn't significantly differ between patients with unilateral and bilateral SCC. Conclusions CE imaging of the vocal cord mucosal capillaries may be useful for the early detection of glottic SCC and pre-cancerous lesions.

[Contact endoscopy with narrow-band imaging for detection of perpendicular vascular changes in benign, dysplastic, and malignant lesions of the vocal folds]

BACKGROUND

Perpendicular vascular changes (PVC) are markers of tumor-induced neoangiogenesis at the vocal folds. Contact endoscopy with narrow-band imaging (CE-NBI) allows a detailed analysis of such vascular changes.

OBJECTIVE

This work intends to evaluate the potential of CE-NBI for diagnosis of benign, dysplastic, and malignant lesions of the vocal folds. In addition, it should be determined whether CE-NBI offers an additional benefit in detecting PVC compared to white-light endoscopy (WLE) and NBI alone.

MATERIALS AND METHODS

Three examiners evaluated histologically verified cases of benign, dysplastic, and malignant lesions of the larynx in WLE, NBI, and CE-NBI (n = 60). In each mode, they examined the lesion for PVC and assessed the lesion's dignity. The proportion of lesions with detected PVC, the statistical measures of performance in detecting high-grade dysplasia and carcinoma, and the interrater variability for each mode were calculated.

RESULTS

CE-NBI proved superior to the other investigated diagnostic methods in terms of detecting PVC and in terms of sensitivity and accuracy in the diagnosis of high-grade dysplasia and carcinoma. A clear association of such pathologies with PVC was seen.

CONCLUSION

CE-NBI detects PVC more frequently and reliably than the other methods investigated. The association of these vascular patterns to high-grade dysplasia and vocal fold carcinomas could be confirmed. Compared to WLE and NBI endoscopy, the diagnostic quality for detecting high-grade dysplasia and carcinoma is increased. Thus, CE-NBI can improve endoscopic differentiation between benign and malignant lesions of the vocal folds by enhancing the detection of PVC.

[Sonography of the head and neck area - Part 1: Endosonography]

Sonography of the head and neck area plays a major role in both outpatient and inpatient ear, nose and throat medicine. Transcervical ultrasound is an important imaging method, especially in lymph node and tumor diagnostics. Its advantage is the ubiquitous availability and the excellent combinability with endoscopy and palpation. Despite decades of experience with sonography in the head and neck area, in contrast to the transcutaneous application, the transoral or endosonographic approach has so far not been widely used. Here it is often not due to the technical capabilities of the examiner, but rather to the unusual approach within the scope of the investigation. In this context, endosonography may be used primarily in tumor diagnostics in order to establish a complete sonographic examination from in- and outside.

Laryngeal Lesion Classification Based on Vascular Patterns in Contact Endoscopy and Narrow Band Imaging: Manual Versus Automatic Approach

Longitudinal and perpendicular changes in the vocal fold’s blood vessels are associated with the development of benign and malignant laryngeal lesions. The combination of Contact Endoscopy (CE) and Narrow Band Imaging (NBI) can provide intraoperative real-time visualization of the vascular changes in the laryngeal mucosa. However, the visual evaluation of vascular patterns in CE-NBI images is challenging and highly depends on the clinicians’ experience. The current study aims to evaluate and compare the performance of a manual and an automatic approach for laryngeal lesion’s classification based on vascular patterns in CE-NBI images. In the manual approach, six observers visually evaluated a series of CE+NBI images that belong to a patient and then classified the patient as benign or malignant. For the automatic classification, an algorithm based on characterizing the level of the vessel’s disorder in combination with four supervised classifiers was used to classify CE-NBI images. The results showed that the manual approach’s subjective evaluation could be reduced by using a computer-based approach. Moreover, the automatic approach showed the potential to work as an assistant system in case of disagreements among clinicians and to reduce the manual approach’s misclassification issue.

Interrater variation of vascular classifications used in enhanced laryngeal contact endoscopy

PURPOSE

Combined use of contact endoscopy (CE) and Narrow Band Imaging (NBI, Olympus^®) is suggested for the visualization of specific vascular changes indicative of glottic neoplasia. We investigated the interrater reliability and agreement in 3 recognized classification systems of vascular changes applied to images from CE + NBI in patients suspected for glottic neoplasia.

METHODS

Six experienced head and neck surgeons familiar with NBI rated 120 images obtained by CE + NBI by 3 classification systems of vascular changes as suggested by Ni et al. (N-C), Puxeddu et al. (P-C), and the European Laryngological Society (ELS-C). Three raters were experienced in CE, and three raters had only limited experience with CE. Crude agreement and Fleiss' kappa with 95% confidence interval were estimated for all 6 raters, and for the 2 levels of expertise for each original classification system and for dichotomized versions of the N-C and the P-C based on suggested neoplastic potential.

RESULTS

The interrater crude agreement and the corresponding kappa values for the ELS-C were good and significantly higher than those for the N-C and P-C for all raters, irrespective of the level of experience with CE (p < 0.0001). There were no significant differences between the N-C and the P-C (p = 0.16). Kappa was considerably improved for both the N-C and the P-C to a level not different from the ELS-C (p = 0.21-0.71) when their 5 original categories were pooled into dichotomized classifications.

CONCLUSION

Difficulties in reliably classifying vascular changes in CE + NBI are evident. Two-tier classification systems are the most reliable.

Contact endoscopy for detection of residual or recurrent disease after radiotherapy for squamous cell carcinoma of the upper aerodigestive tract

OBJECTIVE

The aim of this study was to evaluate contact endoscopy in detecting local treatment failures post-radiotherapy in squamous cell carcinoma of the upper aerodigestive tract.

METHOD

A total of 135 consecutive patients with suspected residual or recurrent cancer after definitive radiotherapy underwent contact endoscopy before biopsy. Contact endoscopy findings were compared with histopathological examination findings. Contact endoscopy could not be completed in 7 patients (5.9 per cent) and histopathological examination was inconclusive in 5 patients (3.7 per cent). The findings of the remaining 123 patients were compared.

RESULTS

The sensitivity, specificity and accuracy of contact endoscopy were 88.75, 88.72 and 86.99 per cent, respectively, with similar results across various sites of upper aerodigestive tract. Inter-observer kappa value was 0.86 (95 per cent confidence interval: 0.79-0.93). The intra-observer kappa value was 0.93 (95 per cent confidence interval: 0.87-1.00) for the first observer and 0.95 (95 per cent confidence interval: 0.90-1.00) for second and third observers.

CONCLUSION

Contact endoscopy showed the same high sensitivity and specificity with low inter- and intra-observer variability in detecting post-radiotherapy failures in cancer of the upper aerodigestive tract as has been shown in non-irradiated tissues in earlier studies.

Evaluation of Vascular Patterns Using Contact Endoscopy and Narrow-Band Imaging (CE-NBI) for the Diagnosis of Vocal Fold Malignancy

The endoscopic detection of perpendicular vascular changes (PVC) of the vocal folds has been associated with vocal fold cancer, dysplastic lesions, and papillomatosis, according to a classification proposed by the European Laryngological Society (ELS). The combination of contact endoscopy with narrow-band imaging (NBI-CE) allows intraoperatively a highly contrasted, real-time visualization of vascular changes of the vocal folds. Aim of the present study was to determine the association of PVC to specific histological diagnoses, the level of interobserver agreement in the detection of PVC, and their diagnostic effectiveness in diagnosing laryngeal malignancy. The evaluation of our data confirmed the association of PVC to vocal fold cancer, dysplastic lesions, and papillomatosis. The level of agreement between the observers in the identification of PVC was moderate for the less-experienced observers and almost perfect for the experienced observers. The identification of PVC during NBI-CE proved to be a valuable indicator for diagnosing malignant and premalignant lesions.

Variant of the Technique for Laryngeal Microsurgery in Cases of Difficult Laryngoscopy

Introduction  Low exposure of the larynx can make laryngeal microsurgery difficult or even impossible. The application of rigid and contact endoscopy enabled oblique and retrograde angled visualization, allowing transoperative staging with greater reach of the anatomical areas. However, there is difficulty or even impossibility of performing the surgical act, due to the incompatibility of the angled path with the straight surgical tools.

Objective  To demonstrate the efficiency of the variant of the technique for laryngeal microsurgery in cases of difficult laryngoscopy and to analyze the new surgical instruments specific to the endoscopic procedure.

Methods  This is a cross-sectional retrospective study, based on the analysis of 30 medical records of patients treated surgically at a philanthropic hospital in the state of Sergipe, Brazil, between the years of 2014 and 2015.

Results  The technical variant used 30- and 70-degree endoscopes that provided complete oblique view of the endolarynx. The association of angled instruments (forceps, suction pumps, retractors and scissors) enabled the execution of the surgical procedures.

Conclusion  The association of rigid endoscopy with angled instruments promoted full visualization of the surgical lesion and operative resolution.

Nasal Contact Endoscopy for the in vivo Diagnosis of Inverted Schneiderian Papilloma and Unilateral Inflammatory Nasal Polyps

Background

Inverted schneiderian papilloma is an entity surrounded by controversies ranging from its etiology to the indication of treatment. Any method that permits histopathological analysis without damage to the tissue studied deserves to be investigated. In this study, we tested a new noninvasive method, i.e., nasal contact endoscopy.

Methods

The main alterations visible on nasal contact endoscopy were described in 11 patients with inverted papilloma and in 8 patients with unilateral inflammatory nasal polyps. The characteristics showing the differentiation between the two entities were defined and these findings were presented to inexperienced examiners.

Results

The significant characteristics for differentiation between the two diseases were the presence of vacuolized cells, cellular heterogeneity, cell clusters, a ciliated respiratory epithelium, and vascular patterns. Two of the three examiners showed a statistically significant high rate of correct diagnosis.

Conclusion

Nasal contact endoscopy may be an effective method for the differential diagnosis between inverted schneiderian papilloma and inflammatory polyps even when the examiner is inexperienced.

Systematic Direct Laryngoscopy: The Lindholm Laryngoscopes

The authors, each with 40 years of experience in laryngology, aim to lay out the general principles and details of a systematic method of direct laryngoscopy for adults, children, and infants. Advances in laryngoscope design and application, advantages of telescopes, use of the operating microscope, and principles of modern anesthesia are highlighted. Particular reference is made to classification of laryngoscopes, advantages of Lindholm laryngoscopes, suspension laryngoscopy, the principles of biopsy, and problems of laryngoscopy. The difficult airway and the obstructed airway are discussed in detail. With the recent renewed interest in investigation and treatment of laryngeal problems and a better understanding of laryngeal physiology and voice production, the future will, no doubt, see new procedures to treat and restore laryngeal function. The fundamentals in this report form a basis for direct laryngoscopy, endolaryngeal microsurgery, laser surgery, and phonosurgery.

Contact Endoscopy of mucosal lesions of oral cavity - Preliminary experience

BACKGROUND

Contact Endoscopy is a non invasive tool to visualise alterations in cell architecture in vivo. In this study we investigated the diagnostic accuracy of Contact Endoscopy in detecting malignancy in oral mucosal lesions.

METHODS

76 patients with oral mucosal lesions requiring biopsy were included. Contact Endoscopy was performed by Otolaryngologist before biopsy and findings recorded. The lesion was then biopsied and sent for histopathological examination by Pathologist who was blinded to Contact Endoscopy findings. Findings of Contact Endoscopy were compared with histopathological findings taking the latter as the gold standard. Two biopsies were reported as 'inconclusive' on histopathological examination and hence excluded from the final analysis. Data of the remaining 74 patients is presented here.

RESULTS

Clinically lesions were diagnosed as ulcero-proliferative lesions in 34 patients, Leukoplakia in 19, Erythroplakia in 9, Lichen planus in 5 and Submucous fibrosis in 7 patients. Histopathological examination revealed presence of malignancy in 97.06% of ulcero-proliferative mucosal lesions, 10.53% of leukoplakia and 33.33% of erythroplakia while corresponding figures on Contact Endoscopy were 94.12%, 5.26% and 11.11% respectively. No malignancy was detected in lichen planus and submucous fibrosis by either technique. When compared with histopathological examination, CE showed sensitivity of 84.21%, specificity of 94.44% and accuracy of 89.19%. No adverse effects on the patients were seen due to the procedure or stain.

CONCLUSION

Contact Endoscopy may be useful in determining cellular structure in vivo without biopsy to detect oral malignancy early. Further studies are suggested.

The role of NBI HDTV magnifying endoscopy in the prehistologic diagnosis of laryngeal papillomatosis and spinocellular cancer

Narrow band imaging (NBI) HDTV (high definition television) magnifying endoscopy is considered to be superior for the accurate display of the microvascular patterns of superficial mucosal lesions. Observation of changes in intraepithelial papillary capillary loops (IPCL) can help distinguish benign from malignant lesions as part of an "optical biopsy." However, IPCL changes in papillomas may be mistaken for spinocellular cancer (SCC). The aim of the study was to determine whether observing microvascular changes alone is sufficient for discriminating between laryngeal SCC and papillomatosis. An additional aim was to identify associated characteristics that could clarify the diagnosis. The study included 109 patients with a suspected laryngeal tumor or papilloma. HDTV NBI magnifying endoscopy was performed during direct laryngoscopy. It was possible to visualize IPCL changes in 82 out of 109 patients (75.2%). In 71 (86.6%) patients, the diagnosis was correctly determined. In 4 (4.9%) cases, the diagnosis of SCC was expressed on the basis of finding pathologic IPCL, but histology did not demonstrate malignancy. To achieve a correct diagnosis using HDTV NBI magnifying endoscopy, it is important not only to observe changes in the shape of IPCL but also to note possible papillary structures with central-axis capillaries typical of papillomatosis.

Assessment of margins in transoral laser and robotic surgery

The growing practice of endoscopic surgery has changed the therapeutic management of selected head and neck cancers. Although a negative surgical margin in resection of neoplasm is the most important surgical principle in oncologic surgery, controversies exist regarding assessment and interpretation of the status of margin resection. The aim of this review was to summarize the literature considering the assessment and feasibility of negative margins in transoral laser microsurgery (TLM) and transoral robotic surgery (TORS). Free margin status is being approached differently in vocal cord cancer (1-2 mm) compared with other sites in the upper aerodigestive tract (2-5 mm). Exposure, orientation of the pathological specimen, and co-operation with the pathologist are crucial principles needed to be followed in transoral surgery. Piecemeal resection to better expose deep tumor involvement and biopsies taken from surgical margins surrounding site of resection can improve margin assessment. High rates of negative surgical margins can be achieved with TLM and TORS. Adjuvant treatment decision should take into consideration also the surgeon's judgment with regard to the completeness of tumor resection.

Contact endoscopy as a novel technique in the detection and diagnosis of oral cavity and oropharyngeal mucosal lesions in the head and neck

Objective:

We aimed to investigate the diagnostic accuracy of contact endoscopy in evaluating oral and oropharyngeal mucosal lesions.

Methods:

Between January 2010 and December 2011, 34 patients with lesions of the oral and oropharyngeal mucosa were enrolled in the study. Comparison between initial contact endoscopy results and ‘gold standard’ tissue biopsy was undertaken.

Results:

Nine patients had histologically confirmed squamous cell carcinoma, 2 had carcinoma in situ, 3 had dysplastic lesions and 20 patients had various benign lesions. Contact endoscopy demonstrated sensitivity and specificity of 89 and 100 per cent respectively in the evaluation of malignant lesions. Benign lesions were correctly categorised in 50 per cent of cases (10/20). The video images from contact endoscopy could not be interpreted in six cases.

Conclusions:

Contact endoscopy demonstrates high sensitivity and specificity in the imaging of malignant lesions with reduced reliability in the evaluation of benign lesions. Significant shortcomings also exist in the design of current technology that we believe represent a significant barrier to the reliable collection of useful video data.

Intra-operative application of confocal endomicroscopy using a rigid endoscope

Objective:

To introduce the application of confocal endomicroscopy during microlaryngoscopy, to enable intra-operative evaluation of human laryngeal epithelium.

Methods:

A rigid endoscope was connected to the scanner head of a Heidelberg Retina Tomograph II confocal laser scanning system via an adapter. The endoscope was gently placed on the surface of a vocal fold through a laryngoscope during microlaryngoscopy.

Results:

The application of confocal endomicroscopy using a rigid endoscope enabled technical improvements (i.e. improved image quality, automatic volume scan, and reduced tissue pressure due to the presence of a perforation plate with central hole at the end of the endoscope) which permitted greater sensitivity and improved handling. Confocal endomicroscopy provided good quality, in vivo, en-face images and enabled an assessment of laryngeal epithelium volume.

Conclusion:

This method enables the surgeon to monitor epithelial changes in pre-malignant lesions. The combination of confocal endomicroscopy together with optical coherence tomography (as a complementary technique that provides optical cross-sections) should be further explored in a formal clinicopathological study.

[Advances in endoscopic diagnosis of dysplasia and carcinoma of the larynx]

To improve the preoperative and intraoperative diagnosis of laryngeal cancer and its precursors, various endoscopic imaging techniques have been developed in recent years. These techniques differ markedly in their specific applications and goals. Precisely distinguishing among normal mucosa, dysplasia and invasive carcinoma with these procedures is necessary. Furthermore, the exact identification of tumor margins should be possible. The long-term goal is the development of optical biopsy. Since so far there have only been small studies regarding the evaluation of the presented methods, it is necessary to establish multi-center trials with large sample sizes to accurately estimate the value of these endoscopic imaging techniques.

Raman spectroscopic methods for classification of normal and malignant hypopharyngeal tissues: an exploratory study

Laryngeal cancer is more common in males. The present study is aimed at exploration of potential of conventional Raman spectroscopy in classifying normal from a malignant laryngopharyngeal tissue. We have recorded Raman spectra of twenty tissues (aryepiglottic fold) using an in-house built Raman setup. The spectral features of mean malignant spectrum suggests abundance proteins whereas spectral features of mean normal spectrum indicate redundancy of lipids. PCA was employed as discriminating algorithm. Both, unsupervised and supervised modes of analysis as well as match/mismatch "limit test" methodology yielded clear classification among tissue types. The findings of this study demonstrate the efficacy of conventional Raman spectroscopy in classification of normal and malignant laryngopharyngeal tissues. A rigorous evaluation of the models with development of suitable fibreoptic probe may enable real-time Raman spectroscopic diagnosis of laryngopharyngeal cancers in future.

Noninvasive imaging of oral neoplasia with a high-resolution fiber-optic microendoscope

BACKGROUND

The purpose of this study was to evaluate the ability of high-resolution microendoscopy to image and quantify changes in cellular and architectural features seen in early oral neoplasia in vivo.

METHODS

A high-resolution microendoscope (HRME) was used to image intact, resected oral squamous carcinoma specimens. HRME images were reviewed and classified as non-neoplastic or neoplastic by expert clinicians. An algorithm based on quantitative morphologic features was also used to classify each image. Results were compared to the histopathologic diagnosis.

RESULTS

HRME images were obtained from 141 sites in resected specimens from 13 patients. Subjective image interpretation yielded sensitivity and specificity of 85% to 90% and 80% to 85%, respectively, whereas the objective classification algorithm achieved sensitivity and specificity of 81% and 77%, respectively.

CONCLUSION

High-resolution microendoscopy of intact oral mucosa can provide images with sufficient detail to classify oral lesions by both subjective image interpretation and objective image analysis.

Optical and molecular techniques to identify tumor margins within the larynx

Failure to remove tumor cells from the larynx significantly increases the risk of local recurrence following surgical excision. Healthy tissue must be preserved to optimize long-term vocal and swallowing function. It is essential to accurately distinguish between healthy mucosa, dysplasia, and invasive carcinoma. Optical and molecular examining technologies have been developed to improve tumor margin identification in vivo. We aimed to review the efficacy of these technologies. Published articles were identified using MEDLINE, EMBASE, and Cochrane central register of controlled trials (CENTRAL). Randomized clinical trials are required to establish the benefit to patients and cost to the health service of using 5-aminolevulinic acid (ALA)-induced fluorescent imaging, contact endoscopy, and optical coherence tomography (OCT). Furthermore, primary research is required to validate other techniques, such as confocal endomicroscopy and Raman spectroscopy, and to develop their clinical applications in the larynx.

Contact endoscopy as a novel technique in the detection and diagnosis of mucosal lesions in the head and neck: a brief review

Background. There are a variety of described noninvasive optical detection techniques for evaluation of head and neck mucosal lesions. Contact endoscopy is a promising method of in vivo microscopic examination whereby a rigid telescope is placed on a previously dye-stained mucosa allowing evaluation of the superficial cell layers of the epithelium. This technique produces real-time, magnified images of cellular architecture of surface mucosa comparable to histology without the need for biopsy. In this review, we will briefly summarize the efficacy of CE in the detection of precancerous and cancerous mucosal lesions and its potential as a novel technique in early diagnosis, monitoring, and preoperative assessment of mucosal lesions of the head and neck. Methods. PUBMED, MEDLINE, and COCHRANE search revealed five prospective articles on contact endoscopy for the diagnosis of mucosal lesions in the head and neck. Results. The literature search yielded five prospective studies examining contact endoscopy for the diagnosis of benign versus malignant head and neck mucosal lesions. These reported a sensitivity and specificity of 77-100%, specificity of 66-100% and an accuracy of 72-92%. Conclusion. Contact endoscopy is a promising optical technology that may be a useful adjunct in the evaluation and diagnosis of benign and malignant head and neck mucosal lesions. Future prospective randomized double-blind studies of this detection method are required.

Optical coherence tomography allows for the reliable identification of laryngeal epithelial dysplasia and for precise biopsy: a clinicopathological study of 61 patients undergoing microlaryngoscopy

OBJECTIVES/HYPOTHESIS

A newly developed microscope-based spectral-domain optical coherence tomography (SD-OCT) device and an endoscope-based time-domain OCT (TD-OCT) were used to assess the inter-rater reliability, sensitivity, specificity, and accuracy of benign and dysplastic laryngeal epithelial lesions.

STUDY DESIGN

Prospective study.

METHODS

OCT during microlaryngoscopy was done on 35 patients with an endoscope-based TD-OCT, and on 26 patients by an SD-OCT system integrated into an operating microscope. Biopsies were taken from microscopically suspicious lesions allowing comparative study of OCT images and histology.

RESULTS

Thickness of the epithelium was seen to be the main criterion for degree of dysplasia. The inter-rater reliability for two observers was found to be kappa = 0.74 (P <.001) for OCT. OCT provided test outcomes for differentiation between benign laryngeal lesions and dysplasia/CIS with sensitivity of 88%, specificity of 89%, PPV of 85%, NPV of 91%, and predictive accuracy of 88%. However, because of the limited penetration depth of the laser light primarily in hyperkeratotic lesions (thickness above 1.5 mm), the basal cell layer was no longer visible, precluding reliable assessment of such lesions.

CONCLUSIONS

OCT allows for a fairly accurate assessment of benign and dysplastic laryngeal epithelial lesion and greatly facilitates the taking of precise biopsies. Laryngoscope, 2010.

Endocytoscopic observation of esophageal squamous cell carcinoma

The endocytoscopy system (ECS), adapted for clinical use in 2003, is an ultra-high-power magnifying endoscope that allows observations at the cell level. ECS is based on the technology of light-contact microscopy. The most evident use of ECS is for real-time, high-resolution diagnosis of nuclear abnormalities, mainly in patients with esophageal cancer. Up to now, three different types of ECS have been available. This diagnostic tool makes it possible to omit histological examination of biopsy samples in approximately 84% of esophageal squamous cell carcinoma, as evidence for both an increase of cell density and nuclear abnormalities is considered to be convincing proof that a lesion is malignant. Here we describe the features of ECS and the background that led to its development, and review the published literature pertaining to the observation of esophageal neoplasms using ECS.

Evaluation of young smokers and non-smokers with Electrogustometry and Contact Endoscopy

Background

Smoking is the cause of inducing changes in taste functionality under conditions of chronic exposure. The objective of this study was to evaluate taste sensitivity in young smokers and non-smokers and identify any differences in the shape, density and vascularisation of the fungiform papillae (fPap) of their tongue.

Methods

Sixty-two male subjects who served in the Greek military forces were randomly chosen for this study. Thirty-four were non-smokers and 28 smokers. Smokers were chosen on the basis of their habit to hold the cigarette at the centre of their lips. Taste thresholds were measured with Electrogustometry (EGM). The morphology and density of the fungiform papillae (fPap) at the tip of the tongue were examined with Contact Endoscopy (CE).

Results

There was found statistically important difference (p < 0.05) between the taste thresholds of the two groups although not all smokers presented with elevated taste thresholds: Six of them (21%) had taste thresholds similar to those of non-smokers. Differences concerning the shape and the vessels of the fungiform papillae between the groups were also detected. Fewer and flatter fPap were found in 22 smokers (79%).

Conclusion

The majority of smokers shown elevated taste thresholds in comparison to non-smokers. Smoking is an important factor which can lead to decreased taste sensitivity. The combination of methods, such as EGM and CE, can provide useful information about the vascularisation of taste buds and their functional ability.

Endocytoscopy in esophageal cancer

Endocytoscopy is a new imaging and magnification technology. It has been developed for observation of cellular structure and applied in the esophageal cancer. In this article we summarize the important aspects of this new modality.

Novel imaging modalities in the detection of oesophageal neoplasia

The prognosis of oesophageal neoplasia is dependent on the stage of the disease at the time of detection. Early lesions have an excellent prognosis in contrast to more advanced stages that usually have a dismal prognosis. Therefore, the early detection of these lesions is of the utmost importance. In recent years, several new techniques have been introduced to improve the endoscopic detection of early lesions. The most important improvement, in general, has been the introduction of high-resolution/high-definition endoscopy into daily clinical practice. The value of superimposing techniques such as chromoendoscopy, narrow band imaging and computed virtual chromoendoscopy onto high-resolution/high-definition endoscopy will have to be proven in randomised cross-over trials comparing these techniques with standard techniques. Important future adjuncts to white-light endoscopy serving as 'red-flag' techniques for the detection of early neoplasia may be broad field functional imaging techniques such as video autofluorescence endoscopy. In addition, real-time histopathology during endoscopy has become possible with endocytoscopy and confocal endomicroscopy. The clinical value of these techniques needs to be ascertained in the coming years.

Microendoscopy of Reinke's Space

Objectives:

Contemporary surgical treatment of the superficial layer of the lamina propria or Reinke's space is most commonly performed through an incision in the overlying vocal fold epithelium. This approach may disrupt normal tissue, induce scarring, and allow extrusion of implanted materials. Previously reported external approaches to Reinke's space required either a laryngofissure or a “minithyrotomy” for access. These surgical approaches were performed without direct imaging of Reinke's space. Instruments placed below the vocal fold epithelium via this external approach were visualized through the translucent vocal fold epithelium. We designed this study to identify the feasibility of limited-access surgery of the lamina propria using microendoscopes placed into Reinke's space through an external approach.

Methods:

A cadaveric human larynx was dissected, and microendoscopes were directly advanced into Reinke's space through a subepithelial puncture of the cricothyroid membrane, as well as lateral fenestration through the thyroid cartilage.

Results:

Photodocumentation of the undersurface of vocal fold epithelium, the opposing surface of the vocal ligament, and the intervening Reinke's space was successfully accomplished.

Conclusions:

Advances in both microendoscopes and accompanying instrumentation permit access to the superficial layer of the lamina propria without disrupting the overlying epithelium. This approach to microendoscopy of Reinke's space may allow for more effective surgical treatment of cysts, chronic edema, vascular abnormalities, atrophy, scarring, and sulcus vocalis.

Single wavelength micro-endoscopy in non-surgical vascular lesion diagnosis & characterization

Malignant and dysplastic epithelial lesions have often been reported to excite vascular responses by histopathological characterization. Little is reported concerning in vivo real-time imaging of vascular patterns and flow in health or disease but the development of miniature imaging instrumentation has now allowed such developments. We describe the application of a selective wavelength (540 nm) epi-illumination Hopkins pattern endoscopic imaging system to image vascular tissues and capillary blood flow in vivo. The contrast mechanism in such imaging was characterized, haemoglobin acting as a chromatic transmission filter despite endoscopy being a non-invasive and therefore principally reflection mode imaging system. In vivo adrenergic vascular responses, capillary flow rate variations over time and variations in normal capillary architecture around the oral cavity were recorded; demonstrating that simple imaging systems can be used for non-surgical diagnosis and characterization of vascular lesions, tumours and treatment responses.

The role of computer-assisted analysis in the evaluation of nuclear characteristics for the diagnosis of precancerous and cancerous lesions by contact laryngoscopy

PURPOSE

Contact endoscopy (CE) through the direct contact with the surface of the mucosa enables in vivo visualization of upper epithelial layers. There is a broad spectrum of laryngeal pathologies, as has been confirmed by earlier CE reports. The aim of the study was to resolve some of the limitations of CE through the application of computer-assisted image analysis. Quantitative and qualitative evaluation of nuclei was applied in the diagnosis of precancerous and cancerous lesions.

MATERIALS AND METHODS

Fifty four patients with various laryngeal pathologies were included in the study. Paraffin section histopathology showed 15 benign lesions, 12 precancerous lesions (5 mild and 7 severe dysplasias) and 27 invasive squamous cell cancers (SCC). After staining the mucous with 1% methylen blue, examination with contact endoscope (Karl Storz, Germany) connected to the C-7070 Wide Zoom Olympus high-resolution camera was performed.

RESULTS

The most discriminative parameters were revealed to be as follows: nucleus area (p<0.001), nuclei density index (p<0.001), elongation coefficient (p<0.05), nucleus area to equivalent area ratio (p<0.05). Computer-assisted image analysis composed with data mining techniques is presented for nuclei categorization.

CONCLUSIONS

We established that computer-aided image analysis can indicate, with a high level of reliability, cases of severe dysplasia and carcinoma. By implementing the technique described in this paper, we can substantially increase the sensitivity of CE.

Potential and present limitation of endocytoscopy in the diagnosis of esophageal squamous-cell carcinoma: a multicenter ex vivo pilot study

BACKGROUND

Endocytoscopy enables the in vivo observation of cellular nuclei in the GI tract. However, potential and present limitations of endocytoscopy have not been elucidated in detail.

OBJECTIVE

To investigate whether endocytoscopic images of cancerous and normal squamous cells in the esophagus correspond with horizontal histology of the mucosal surface.

DESIGN

An ex vivo pilot study.

SETTING

Multiple academic institutions.

MATERIALS

Endoscopically or surgically resected human esophagus obtained between May 2006 and July 2006.

INTERVENTIONS

Endocytoscopic observation was performed on small areas of cancerous lesions and corresponding normal squamous cells. Biopsy specimens were then retrieved from the areas scanned to make horizontal histologic sections.

MAIN OUTCOME MEASUREMENTS

Comparison of the images obtained by endocytoscopy and histology and comparison of the mean numbers of the total nuclei per endocytoscopic image obtained in cancerous and normal areas.

RESULTS

Twenty-seven esophageal squamous-cell carcinomas were acquired and evaluable pairs of an endocytoscopic image and a histological picture were obtained at 12 cancerous and 14 normal areas that showed similar morphologies between them. The mean (+/-SD) numbers of the total nuclei per image were 129+/-14.8 at the normal area and 550+/-66.5 at the cancerous area, respectively, which were significantly different between groups (P<.0001).

LIMITATIONS

Only a comparison of cancerous and normal squamous cells in the esophagus at the ex vivo setting.

CONCLUSIONS

Although endocytoscopic images closely correlated with conventional histology in the esophagus, appropriate preconditioning to constantly obtain sufficient image quality and universal criteria for endocytoscopic diagnosis of various diseases are essential before clinical application.

Comparison of contact endoscopy and frozen section histopathology in the intra-operative diagnosis of laryngeal pathology

Andrea et al. were the first to use contact endoscopy in the diagnosis of laryngeal disease, in 1995. This method enables in vivo microscopy of laryngeal mucosa.

In the present study, comparison of contact endoscopy with frozen section histopathology was performed in 142 patients with various diseases of the larynx. Paraffin section histopathology diagnosed 70 benign lesions, 23 precancerous lesions and 49 malignant lesions. Frozen section histopathology showed a sensitivity of 89.8 per cent, a specificity of 98.9 per cent and an accuracy of 95.7 per cent (χ2 = 1.5; p = 0.18). Frozen histopathology diagnosed 45 malignant lesions, including one false positive and five false negative results. Contact endoscopy yielded a sensitivity of 79.59 per cent, a specificity of 100 per cent and an accuracy of 92.95 per cent (χ2 = 8.1; p = 0.002). All malignant lesions diagnosed by contact endoscopy were confirmed by histopathology; contact endoscopy failed to recognise malignant lesions in 10 patients.

Contact endoscopy is preferable to frozen section histopathology as it is noninvasive, provides information on microscopic diagnosis and laryngeal lesion margins, and enables visualisation of the laryngeal mucosa microvasculature. The use of contact endoscopy along with frozen section histopathology improves diagnostic accuracy and allows for operative (or other) therapy to continue according to the results obtained.

Recent technological developments: in situ histopathological interrogation of surgical tissues and resection margins

OBJECTIVES

The tumour margin is an important surgical concept significantly affecting patient morbidity and mortality. We aimed in this prospective study to apply the microendoscope on tissue margins from patients undergoing surgery for oral cancer in vivo and ex vivo and compare it to the gold standard "paraffin wax", inter-observer agreement was measured; also to present the surgical pathologist with a practical guide to the every day use of the microendoscope both in the clinical and surgical fields.

MATERIALS AND METHODS

Forty patients undergoing resection of oral squamous cell carcinoma were recruited. The surgical margin was first marked by the operator followed by microendoscopic assessment. Biopsies were taken from areas suggestive of close or positive margins after microendoscopic examination. These histological samples were later scrutinized formally and the resection margins revisited accordingly when necessary.

RESULTS

Using the microendoscope we report our experience in the determination of surgical margins at operation and later comparison with frozen section and paraffin section margins "gold standard". We were able to obtain a sensitivity of 95% and a specificity of 90%. Inter-observer Kappa scores comparing the microendoscope with formal histological analysis of normal and abnormal mucosa were 0.85.

CONCLUSION

The advantage of this technique is that a large area of mucosa can be sampled and any histomorphological changes can be visualized in real time allowing the operator to make important informed decisions with regards the intra-operative resection margin at the time of the surgery.

Histologic assessment of epithelial thickness in early laryngeal cancer or precursor lesions and its impact on endoscopic imaging

The objective of the study was to assess the epithelial thickness in different lesions of the vocal folds in order to gain more information about its influence on endoscopic imaging. Retrospective study including 161 patients undergoing surgery for a total of 206 benign and malignant lesions of the vocal folds. Laryngoscopy and autofluorescence endoscopy were the first line of investigation for these lesions. Diagnosis was confirmed by histopathology in all cases. Morphometric measurement of epithelial thickness was performed using a normal white light and an autofluorescence microscope. The vocal fold mucosa revealed a progressive thickening from normal epithelium (NE = 147 microm) over the different grades of epithelial dysplasia (EDI = 258 microm, EDII = 301 microm, CIS = 445 microm) to early invasive carcinoma (EIC = 974 microm), while benign lesions presented only a slight epithelial thickening of an additional 100 microm. In such a manner, moderate dysplasia showed a double increase, carcinoma in situ a triple increase and early invasive carcinoma even a sixfold increase of the mean epithelial thickness compared to normal laryngeal mucosa. As fluorescence inducing light has a penetration depth of approximately 300 microm, a marked loss of autofluorescence was recognized from moderate dysplasia onwards, while mild dysplasia simply revealed a slight loss of fluorescence. Autofluorescence microscopy demonstrated a threefold higher fluorescence intensity of the submucosal connective tissue compared to the epithelium, which showed always the same weak intensity independent of the grade of dysplasia. In most cases laryngeal epithelium demonstrates progressive thickening during cancer genesis leading to a loss of autofluorescence.

Contact endoscopy of the nose in patients with Rendu-Osler-Weber syndrome

OBJECTIVE

Teleangiectases are the source of hemorrhage in many HHT patients. Most frequent site of bleeding is the nose and more than 90% of all individuals with HHT suffer from recurrent epistaxis. Despite all efforts, treatment of epistaxis in HHT continues to be a problem for many otorhinolaryngologists, who can alleviate recurrent nosebleeds by Septodermoplasty or laser therapy, but rarely can stop nasal hemorrhages permanently. Recurrence is almost inevitable, but the mechanisms of recurrence are not fully understood.

METHODS

Prior to routine Nd:YAG laser therapy of nasal telangiectases the nasal mucosa of 17 patients with HHT according to the clinical diagnostic criteria of the HHT Foundation International was examined with a 0 degrees contact rhinoscope in areas with clinically visible telangiectases as well as in clinically normal mucosa. The digitally recorded images were compared to findings of a group of five healthy volunteers and the findings of five patients with polypoid sinusitis.

RESULTS

Visualization of subepithelial vessels was feasible in all individuals of the study group as well as the control groups. Dilated vascular loops and tortuous vessels could be found in the study groups as well as in the control group, but the overall density of telangiectatic vessels was on an average higher in the HHT group. The process of vessel dilatation and tortuous configuration seemed to progress with age.

CONCLUSION

Contact endoscopy allows the investigation of the angioarchitecture of capillaries of the nasal mucosa in vivo. This observation may be of significance for studies of nasal diseases, which are accompanied by epistaxis. With this regard it seems to be of special interest for studies of HHT.

Laser Scanning Microscopy of the Human Larynx Mucosa: A Preliminary, Ex Vivo Study

OBJECTIVE

Laser scanning microscopy (LSM) supplies in vivo information from epithelia up to depths between 0.1 to 0.5 mm. The aim of this ex vivo prospective pilot study was to investigate the potential use of LSM for the diagnosis of laryngeal cancer and its precursors.

METHODS

Forty-three larynx specimens of 26 patients (age 35-61 years, mean age 51.9+/-9.5 years; 7 women and 19 men) with laryngeal lesions were investigated with LSM. The LSM findings were compared with histopathologic sections. The following criteria were used for characterization of cancerous lesions: enlarged nuclei, enlarged cells with variable shapes, cluster of cells, increased nucleus/cytoplasm ratio, irregular cell architecture, and loss of cellular junctions characterized by lack of visualization of the cell membrane.

RESULTS

LSM enables the visualization of epithelium up to the basement membrane, Reincke space, the subepithelial vessels, and the fibers of the subepithelial space. In contrast to the squamous epithelium, the respiratory epithelium bears kinocilia. The beat of the cilia and the directed mucous transport can be observed ex vivo. With the use of the presented malignancy criteria, a sensitivity of 72.7% and a specificity of 82.9% for differentiation of dysplasia and benign laryngeal lesions from cancer were reached.

CONCLUSIONS

LSM in an ex vivo manner supplies microscopic images up to the subepithelial space. LSM could represent a new technology in laryngology to visualize larynx epithelia. In the next step, in vivo LSM will be applied to evaluate laryngeal lesion in vivo.