Narrow band imaging (NBI) during medical thoracoscopy: first impressions

Advances in the diagnosis and follow-up of pleural lesions: a scoping review

INTRODUCTION

Pleural lesions may have heterogeneous presentation and causes. In recent years, there have been significant advances in pleural lesions diagnostics. The aim of this review is to provide an overview of the state-of-the-art, and recent updates for diagnostic modalities and monitoring regimes for pleural lesions.

AREAS COVERED

A literature search was conducted through PubMed and Web of Science for relevant articles published from 1 January 2000- 1 March 2023. This article critically appraises the radiological modalities and biopsy techniques that are employed in pleural lesions diagnostics, including chest radiography, thoracic ultrasound, computed tomography, F-fluorodeoxyglycose positron emission tomography, magnetic resonance imaging, percutaneous, and thoracoscopic pleural biopsies with reference to their strengths, limitations, and clinical use. The review asserts also the available literature regarding monitoring algorithms.

EXPERT OPINION

Despite the recent advances in the field, there are several key areas for improvement, including the development and validation of minimal invasive methods and tools for risk stratification, the integration of multi-omics technologies, the implementation of standardized, evidence-based diagnostic and monitoring guidelines and increased focus on research and patient-centric approaches. The broad establishment of dedicated pleural clinics may significantly assist toward this direction.

Multimodal approach to the management of malignant pleural effusions: role of thoracoscopy with pleurodesis and tunneled indwelling pleural catheters

Malignant pleural effusion (MPE) is associated with a median survival of 3–6 months and causes significant symptoms affecting the overall quality of life in patients with advanced malignancies. Despite the high incidence of recurrent MPE, less than 25% of patients undergo a definitive pleural intervention as recommended by guidelines. In this review, we summarize the latest guidelines for management of MPE by various societies and discuss a multimodal approach in these patients using thoracoscopy with pleurodesis using talc insufflation and placement of tunneled indwelling pleural catheters (TIPC). We also address the role of diagnostic thoracoscopy for histologic and molecular diagnosis and outline our approach to patients with known or suspected MPE.

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.

Prospective Comparative Study of Laparoscopic Narrow Band Imaging (NBI) Versus Standard Imaging in Gynecologic Oncology

BACKGROUND

Narrow band imaging (NBI) is an optic filtration enhancement for endoscopy that uses two wavelengths of light (415 and 540 nm) to highlight superficial microvascular patterns. It has been successfully utilized to improve identification of lesions with abnormal vasculature, which is associated with endometriosis and endometrial cancer. Case studies suggest it may also facilitate surgical staging of gynecologic cancer, which is critical in determining appropriate adjuvant therapies. A technology that enhances the ability to identify metastatic disease during minimally invasive surgery (MIS) could make an important difference in patient outcomes.

METHODS

A prospective comparative study was conducted to evaluate patients with clinical indication for diagnostic or operative laparoscopy. All received white light imaging followed by NBI during the same procedure. Suspicious lesions were examined and photographed, using both modalities, before excision. The two techniques were compared. Positive predictive value, negative predictive value, and diagnostic accuracy in identifying histologically confirmed metastatic lesions were assessed, using appropriate statistical methods.

RESULTS

Of 124 patients enrolled in the study, 94 were evaluable; 30 did not undergo MIS and were therefore excluded. A significantly higher number of peritoneal abnormalities were identified with NBI versus white light imaging (P = 0.0239). However, no statistically significant difference (P = 0.18, patient level) was observed in identification of histologically confirmed metastatic disease.

CONCLUSIONS

NBI imaging provides a unique contrast between peritoneal surface and microvascular patterns. However, the results of this study suggest that NBI-enhanced laparoscopy does not provide superior detection of peritoneal surface malignancy compared with standard white light high-definition laparoscopy.

Medical thoracoscopy and its evolving role in the diagnosis and treatment of pleural disease

Establishing the etiology of exudative pleural effusions in the setting of an unrevealing pleural fluid analysis often requires biopsies from the parietal pleura. While closed pleural biopsy (CPB) has been a popular minimally-invasive approach, it has a poor diagnostic yield, barring a diagnosis of tuberculous pleurisy. Medical thoracoscopy (MT) is a minimally-invasive ambulatory procedure performed under local anesthesia or moderate sedation which allows for direct visualization of biopsy targets as well as simultaneous therapeutic interventions, including chemical pleurodesis and indwelling tunneled pleural catheter (ITPC) placement. The excellent yield and favorable safety profile of MT has led to it replacing CPB for many indications, particularly in the management of suspected malignant pleural effusions. As experience with MT amongst interventional pulmonologists has grown, there is an increased appreciation for its important role alongside percutaneous and surgical approaches in the diagnosis and treatment of pleural disease.

Specific computed virtual chromoendoscopy for detection of peritoneal carcinomatosis: an animal study

BACKGROUND

Detection of an incipient Peritoneal Carcinomatosis (PC) is still challenging, and there is a crucial need for technological improvements in order to diagnose and to treat early this condition. The aim of this study was to create a murine model of incipient PC and to explore the PC with Fujinon Intelligent Chromo Endoscopy (FICE) in order to determine the wavelengths of the white light (WL) spectre that offer the highest contrast between PC nodules and surrounding peritoneum.

METHODS

Eighteen BALB/c mice had intraperitoneal injection of murine colonic cancer CT26 cells. Peritoneal exploration with FICE was performed at different times. For each PC nodule, 1 WL and 10 FICE images were recorded. Each image was then divided into its elementary red, green and blue band images. Depending on the FICE channel, each elementary image corresponds to a specific wavelength of the WL spectre. Through numerical analysis of these images, the value of the nodule and the background peritoneum were obtained, and the contrast value was calculated. Contrast values obtained with the different wavelengths were then compared.

RESULTS

PC grew in all the mice. The number as well as the size of PC nodules was increasingly high depending on the day of exploration. Mean PCI was 1.6 ± 1.2 at day 5, 7.7 ± 2.6 at day 8 and 15.0 ± 7.3 at day 10. A total number of 1805 elementary images of PC nodules were analysed. The wavelength that offered the best contrast between PC nodules and background peritoneum was 460 nm with a mean contrast value of 0.240 ± 0.151 (p < 0.0001).

CONCLUSION

This murine model of incipient PC is effective, reliable and reproducible. A monochromatic light with a wavelength at 460 nm offers the highest contrast between PC nodules and background peritoneum, allowing a better detection of PC.

Intra-patient comparison of parietal pleural biopsies by rigid forceps, flexible forceps and cryoprobe obtained during medical thoracoscopy: a prospective series of 80 cases with pleural effusion

BACKGROUND

There is only few data available on the use of cryotechnique during medical thoracoscopy.

METHODS

Medical thoracoscopy was performed in consecutive patients with pleural effusion. Prospectively, biopsies were taken by rigid forceps, flexible forceps and cryoprobe. Specimen size, depth and diagnostic yield were compared.

RESULTS

80 Patients were included. 408 biopsies were taken (205 rigid biopsies, 104 flexible biopsies, 99 cryobiopsies). Mean surface area of rigid biopsies was 22.6 ± 20.4 mm(2) (flexible biopsies: 7.1 ± 9.3 mm(2), cryobiopsies: 14.4 ± 12.8 mm(2)). Rigid biopsies were significantly larger than cryobiopsies (p < 0.001) and flexible biopsies (p < 0.001), crybiopsies were significantly larger than flexible biopsies (p < 0.01). A deep biopsy containing fatty tissue was harvested in 63 % of rigid biopsies (cryobiopsy: 49.5 % flexible biopsy: 39.5 %). In 79/80 cases (98.7 % 95 % CI cannot be calculated) a diagnosis was obtained by rigid biopsy (cryobiopsy: 73/80 cases (91.3 % 95 % CI 86.0 - 96.5 %), flexible biopsy: 74/80 cases (92.5 % 95 % CI 88.6 - 97.4 %)). Diagnostic yield achieved with cryobiopsies was inferior to the yield of rigid biopsies (Difference: 12.7 %), but non-inferior to flexible biopsies (Difference: 6.5 %).

CONCLUSION

Cryobiopsies in medical thoracoscopy are safe with high diagnostic yield, non-inferior to flexible biopsies with increased tissue quantity and quality. Cryotechnique can develop an important role in medical thoracoscopy in the near future when rigid thoracoscopy is not available.

A feasibility study of the use of computed virtual chromoendoscopy for laparoscopic evaluation of peritoneal metastases

BACKGROUND

Detection of an incipient peritoneal carcinomatosis (PC) is still challenging, and there is a crucial need for technological improvements in order to diagnose and to treat early this condition. Fujinon Intelligent Chromo Endoscopy (FICE) is a spectral image processing technology that enhances the contrast of the target tissue. The aim of this study is to investigate the usefulness of FICE system during peritoneal endoscopy and to establish the optimal FICE preset(s) for peritoneal exploration and PC detection.

METHODS

A total of 561 images corresponding to 51 different areas of PC nodules and normal peritoneum were recorded during peritoneal endoscopies (For each area, one white light endoscopy (WLE) image and 10 FICE images). Three groups of 5 evaluators each: senior surgeons, surgical residents and medical students assessed these images. In a first questionnaire, the evaluators gave a score ranging from 1 to 10 to each image, and the three best FICE channels were determined. In a second questionnaire, five criteria were studied specifically: contrast, brightness, vascular architecture, differentiation between organs and detection of PC. The evaluators ranked the WLE and the three best FICE channel images according to these criteria.

RESULTS

The three best FICE channels were channels 6, 2 and 9 with mean scores of 6.21 ± 1.59, 6.17 ± 1.48 and 6.06 ± 1.52, respectively. FICE Channel 2 was superior to WLE and other FICE channels, in terms of contrast (p < 10^-4), visualization of vascular architecture (p < 10^-4), differentiation between organs (p < 10^-4) and detection of PC (p < 10^-4); and ranked first in 38.8, 41.5, 31 and 46.9 % of the cases, respectively.

CONCLUSION

FICE system provides adequate illumination of the abdominal cavity and a unique contrast that enhances the vascular architecture. FICE Channel 2 is the optimal channel for peritoneal exploration and could be a useful tool for the diagnosis of PC during peritoneal explorations.

Laparoscopic narrow band imaging for detection of occult cancer metastases: a randomized feasibility trial

BACKGROUND

Selection of cancer treatment fundamentally relies on staging of the underlying malignancy. The aim of this study was to evaluate the feasibility and effectiveness of laparoscopic narrow band imaging (NBI) for operative staging and detection of occult peritoneal cancer metastases.

METHODS

A randomized, controlled feasibility trial with crossover design evaluating adult patients with gastrointestinal or gynecologic malignancies who have a clinical indication for diagnostic laparoscopy was conducted. Twenty-three patients were randomized to white-light followed by NBI laparoscopy (n = 11) or NBI followed by white-light laparoscopy (n = 12) using the Olympus Evis Exera II system. Three patients were excluded from analysis.

RESULTS

In all 20 study patients, the abdominal cavity was sufficiently illuminated. An enhanced contrast of microvasculature and organ surface pattern was appreciated. Eight of the 20 patients (40%) were found to have metastases of the peritoneal surface. While NBI did not show any additional peritoneal lesions, 2 of the 63 suspicious-appearing nodules seen on white-light imaging were not visible on NBI (p = 0.50). The median diameter of all the nodules identified was 2 mm (range 1-50 mm) and was identical with each method.

CONCLUSIONS

The information from this feasibility study demonstrated that NBI provides adequate illumination of the abdominal cavity and a unique contrast that enhances microvasculature and architectural surface pattern. The results suggest that NBI laparoscopy is not superior in detecting peritoneal metastases compared to standard white-light laparoscopy, but might provide a technology that could be applied for other abdominal pathologies.

Medical thoracoscopy: rigid thoracoscopy or flexi-rigid pleuroscopy?

PURPOSE OF REVIEW

In managing pleural diseases, medical thoracoscopy is often performed as a diagnostic and/or therapeutic procedure, particularly in undiagnosed pleural effusions. Flexi-rigid pleuroscopes are now widely available as an alternative to conventional rigid thoracoscopes. There is an ongoing debate on which is the better instrument. This review analyses the current literature that compared rigid and flexi-rigid approaches, and outlines the medical advances that may influence the future role of thoracoscopy.

RECENT FINDINGS

Both rigid and flexi-rigid thoracoscopies are well tolerated. Although biopsies are smaller with flexi-rigid biopsy forceps, two small randomized trials reported similar diagnostic yield using either instrument. No studies have specifically examined patient comfort or the outcome of talc poudrage using the two devices. New techniques (e.g. insulated-tip knife and cryobiopsy) have been used as adjuncts with flexi-rigid pleuroscopy to overcome the difficulties in sampling thickened pleura.

SUMMARY

The rigid and flex-rigid instruments have different merits and limitations. Both approaches provide comparable diagnostic yields in the overall patient population undergoing diagnostic thoracoscopy, though their performances specifically in patients with fibrotic pleural thickening have not been examined. Operators using the flexi-rigid approach should have alternative strategies for sampling thickened pleura. Advances in cytopathology and imaging-guided biopsy will likely reduce the need of medical thoracoscopy in the future.

Laryngeal Tumor Detection and Classification in Endoscopic Video

The development of the narrow-band imaging (NBI) has been increasing the interest of medical specialists in the study of laryngeal microvascular network to establish diagnosis without biopsy and pathological examination. A possible solution to this challenging problem is presented in this paper, which proposes an automatic method based on anisotropic filtering and matched filter to extract the lesion area and segment blood vessels. Lesion classification is then performed based on a statistical analysis of the blood vessels' characteristics, such as thickness, tortuosity, and density. Here, the presented algorithm is applied to 50 NBI endoscopic images of laryngeal diseases and the segmentation and classification accuracies are investigated. The experimental results show the proposed algorithm provides reliable results, reaching an overall classification accuracy rating of 84.3%. This is a highly motivating preliminary result that proves the feasibility of the new method and supports the investment in further research and development to translate this study into clinical practice. Furthermore, to our best knowledge, this is the first time image processing is used to automatically classify laryngeal tumors in endoscopic videos based on tumor vascularization characteristics. Therefore, the introduced system represents an innovation in biomedical and health informatics.

Lung cancer coexisting with ipsilateral pleural effusion

SUMMARY 

Invasion beyond the elastic layer of the visceral pleura and/or diffuse pleural metastatic spread affects negatively survival in lung cancer. Presence of pleural effusion is also associated with poor prognosis, and image techniques can be of great help for diagnosis. When pleural fluid cytology is negative, thoracoscopy is advisable before attempting tumor resection, in order to detect unsuspected pleural metastases. If widespread pleural malignancy is confirmed, chemical pleurodesis using graded talc (with particles larger than 20 µm in diameter) is the best option, unless the lung is unable to re-expand. In this case, or when a previous pleurodesis has failed, or there is a short life expectancy, placement of a indwelling pleural catheter is the treatment of choice.

Pleuroscopy in 2013

Pleuroscopy provides a window to the pleural space while enabling biopsy of the parietal pleura under direct visual guidance for effusions of unknown etiology, guided chest tube placement, and pleurodesis for recurrent pleural effusions or pneumothoraces in selected patients. The procedure enjoyed resurgence when thoracic surgeons introduced the technique for video-assisted thoracic surgery (VATS). VATS is performed under general anesthesia with single-lung ventilation; pleuroscopy is performed in an endoscopy suite using nondisposable rigid or flex-rigid instruments, local anesthesia, and conscious sedation. Pleuroscopy is less invasive; in this review, we discuss the indications, complications, techniques, and recent advances in the procedure.

Current and future options for the diagnosis of malignant pleural effusion

INTRODUCTION

Malignant pleural effusion (MPE) is a frequent problem faced by clinicians, but tumor pleural involvement can be seen without effusion.

AREAS COVERED

Imaging, pleural fluid analysis, biomarkers for MPE, needle pleural biopsy and thoracoscopy. To prepare this review, we performed a search using keywords: 'diagnosis' + 'malignant' + 'pleural' + 'effusion' (all fields) in PubMed, and found 4106 articles overall (until 16 January 2013, 881 in the last 5 years).

EXPERT OPINION

Ultrasound techniques will stay as valuable tools for pleural effusions. Biomarkers in pleural fluid do not currently provide an acceptable yield for MPE. In subjects with past history of asbestos exposure, some serum or plasma markers (soluble mesothelin, fibulin) might help in selecting cases for close follow-up, to detect mesothelioma early. Needle pleural biopsy is justified only if used with image-techniques (ultrasound or CT) guidance, and thoracoscopy is better for both diagnosis and immediate palliative treatment (pleurodesis). Animal models of MPE and 'spheroids' are promising for research involving both pathophysiology and therapy. Considering the possibility of direct pleural delivery of nanotechnology-developed compounds-fit to both diagnosis and therapy purposes ('theranostics')-MPE and mesothelioma in particular are likely to benefit sooner than later from this exciting perspective.