THE VALUE OF ULTRASOUND-GUIDED FIBEROPTIC BRONCHOSCOPY

Diagnostic yield of EBUS-TBNA for the evaluation of centrally located peribronchial pulmonary lesions

BACKGROUND

The purpose of this study was to evaluate the diagnostic yield of endobronchial ultrasound with real-time-guided transbronchial needle aspiration (EBUS-TBNA), endobronchial forceps biopsy (EBBx), and 2D fluoroscopic-guided transbronchial forceps biopsy (TBLBx) for centrally located peribronchial lung lesions.

METHODS

A retrospective chart review of consecutive patients who underwent EBUS-TBNA of centrally located peribronchial lesions, that is, medial margin of the mass within inner third of hemithorax by computerized tomography scan. Patients who underwent EBUS-TBNA for lymph node sampling were excluded.

RESULTS

Thirty-two cases met the inclusion criteria. The mean age was 69±12 years. Sixteen (50%) were male patients. Of the 32 EBUS-TBNA cases, 13 underwent concomitant TBLBx (group 1), 8 had concomitant EBBx (group 2), and 11 had EBUS-TBNA alone (group 3). In group 1, the diagnostic yield of EBUS-TBNA was 95% (n=12/13), whereas the yield of TBLBx was 61% (n=8/13). In group 2, the diagnostic yield of EBUS-TBNA was 100% (n=8/8), whereas EBBx was positive in 75% (n=6/8). In group 3, the diagnostic yield of EBUS-TBNA was 91% (n=10/11). Overall diagnostic yield of EBUS-TBNA of centrally located peribronchial lung lesions was 94% (n=30/32).

CONCLUSION

Where available, EBUS-TBNA of centrally located peribronchial lung lesions should be given a strong consideration given its high diagnostic yield.

Autofluorescence Bronchoscopy and Endobronchial Ultrasound: A Practical Review

Endobronchial ultrasound (EBUS) and autofluorescence bronchoscopy (AFB) are the two technologies to have the largest impact on diagnostic bronchoscopy in the last forty years. The AFB utilizes inherent tissue properties to identify preinvasive lesions of the central airways. The EBUS can accurately define airway invasion versus compression from tumors, guide transbronchial needle aspiration of hilar and mediastinal lymph nodes, and predict, based on ultrasound morphology, whether peripheral nodules are benign or malignant. It is also extremely useful for determining the proximal and distal extent of tumors in and around the airway, and aid in surgical planning. This article will review the principles and clinical applications of these two technologies.

Bronchoscopy and needle biopsy techniques for diagnosis and staging of lung cancer

Lung cancer is the leading cause of cancer deaths in the United States. The individual therapeutic approach and prognosis depends on accurate diagnosis and staging. Flexible bronchoscopy (FB) and transthoracic needle biopsy (TNB) are the most widely used techniques for this purpose. This article provides a critical overview of indications, diagnostic yield, and limitations of bronchoscopy and TNB in the diagnosis of lung cancer.

Correlation between endobronchial ultrasonography (EBUS) images and histologic findings in normal and tumor-invaded bronchial wall

The aim of this study was to examine the ability of endobronchial ultrasonography (EBUS) to image the bronchial wall structure in order to assess the depth of bronchial tumor invasion. Sixty-one patients who underwent lobectomy, pneumonectomy or forceps biopsy were included in this study. In 21 patients with bronchoscopically visible bronchial malignant tumors, EBUS was performed during bronchoscopy. In the remaining 40 patients, ultrasonography was performed on the resected specimens. The EBUS findings obtained using thin ultrasonic probes (20 MHz radial scanner) were compared with the macroscopic and histologic findings of the corresponding areas in the resected specimens. When the bronchial walls were imaged while immersed in normal saline, six ultrasonically distinct layers were detected in the cartilaginous and membranous portions. A similar wall structure was imaged when EBUS was performed during bronchoscopy using a latex balloon sheath. The image of the lamina propria and submucosa was occasionally compressed and mixed with a balloon echo due to the latex balloon sheath, whereas the cartilage layer was always distinctly imaged. A good correlation was observed between the EBUS-determined cartilage thickness and the actual histologic measurement, as measured with vernier calipers. Malignant tissues were imaged as hypoechoic areas, and tumor invasion of the cartilage layer was clearly detected. In conclusion, using high-resolution (20 MHz) ultrasonic probes, the bronchial wall structure could be imaged as six distinct layers. The cartilage layer was easily identified and could be used as a reference to evaluate the rest of the bronchial wall structure.

Semi-invasive and invasive procedures for the diagnosis and staging of lung cancer. II. Bronchoscopic and surgical procedures

Each of the various techniques used for the diagnosis and staging of lung cancer has its advantages and limitations (Table 1). Imaging has a major role in guiding these procedures and deciding which of them is most appropriate in a given clinical setting. A CT examination by which the size and location of the parenchymal lesion and the presence and location of enlarged lymph nodes can be determined is a prerequisite for all sampling procedures. As a general rule, when attempting to diagnose a solitary pulmonary nodule or mass, central lesions are more easily approached by the bronchoscopic route, whereas a transthoracic route is preferred for peripheral lesions. Bronchoscopy is often performed using fluoroscopic guidance, and the recently developed CT fluoroscopy and endoscopic ultrasound have the potential to facilitate transbronchial needle aspiration. A recent advent in imaging of lung cancer has been the introduction of positron emission tomography to the diagnostic work-up of lung cancer. Although this technique has been shown to be highly accurate in determining the malignant or benign nature of lesions, it does not enable histologic diagnosis. In each case, the most appropriate diagnostic procedure should be tailored to suit the specific requirements determined by the characteristics of the disease process, institutional availability of the various diagnostic procedures, and patient preferences, when possible.

Future of flexible bronchoscopy

Despite some potential "threats" (Table 3), the future of bronchoscopy is likely full with ever expanding applications in clinical medicine and research (Tables 1 and 2). The role of bronchoscopy in lung cancer continues to expand and the usefulness of newer techniques needs to be established. The role of FB is also ever expanding in the immuno compromised host and critically ill patients. Future studies, however, should concentrate on patient outcome, especially survival and performance status. Therapeutic bronchoscopy has been extended to many areas and the emphasis of future research will likely continue to be at the molecular level rather than on studies of better instruments for retrieval purposes. The most exciting developments are likely to be in the field of gene therapy, which has made remarkable progress in the past decade. Gene therapy can be a powerful technology, but several hurdles must be overcome to make gene therapy a reality for treating human disease in the future. As the cost of technology continues to challenge health care delivery systems, a major challenge for the future of bronchoscopy is to evaluate new technologies and applications based on their impact on patient outcome, survival, and management of cost.