Background: EBUS guided trans-bronchial biopsy became routine in diagnosis of peripheral pulmonary lesions (PPL). Suction catheter-biopsy is a technique for obtaining a tissue sample from peripheral lung parenchyma. Aim of this study was to evaluate diagnostic efficiency, feasibility and safety of EBUS guided suction catheter-biopsy (SCB) in comparison to trans-bronchial biopsy (TBB) in diagnosis of PPL. The main intention was to demonstrate non-inferiority of the technique over trans-bronchial biopsy, especially when used under navigation of the EBUS.Methods: Radial EBUS probe (UM-3R, Olympus Co, Japan.) without guiding sheath was used to navigate suction catheter and TBB forceps to the PPL. The catheter was connected to the collection canister via vacuum pump. The SCB specimens were fixed with 10% buffered formalin.Results: There were 168 patients enrolled in this study; 69.9% males and 30.1% females. Main lesion diameter was 4.1±1.9 cm. Majority of patients, 131(77.9%) were diagnosed with lung cancer. Per-biopsy calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for EBUS-SCB were 92.4%, 100%, 100% and 67.7%, respectively. Corresponding values for EBUS-TBB were 92.3%, 100%, 100% and 69.7%. Only the size of the lesion significantly influenced (p=0.005) diagnostic performance. Complications occurred in 2 patients; one pneumothorax and one excessive bleeding.Conclusion: EBUS guided SCB is efficient, feasible and safe in diagnosis of peripheral lung cancer. The technique is complementary to trans-bronchial biopsy.

Narrow Band Imaging (NBI) videobronchoscopy is a new technique for visualization of microvascular changes in bronchial mucosa. The primary aim of this study was to evaluate relation between vascular patterns visualized by NBI and histology of lung cancer. We prospectively evaluated 65 patients with suspected lung cancer scheduled for bronchoscopy. NBI followed conventional WL videobronchoscopy. After identification of endoscopically visible tumor, NBI was used to determine predominant type of pathological vascular pattern (dotted, tortuous, abrupt-ending blood vessels-Shibuya descriptors). All the lesions were biopsied and histologically confirmed. There were 81.5 % male and 18.5 % female patients evaluated in the study. Lung cancer was confirmed in all patients; 63.1 % were diagnosed with squamous cell lung cancer (SCC), 24.6 % had adenocarcinoma, 9.2 % had small-cell (SCLC) and 3.1 % large-cell lung cancer (LC). Dotted blood vessels were significantly (p < 0.000) associated with adenocarcinoma, identified in 68.4 % adenocarcinoma and 31.6 % SCC. Tortuous blood vessels were identified in 72 % SCC, 8 % adenocarcinoma, 12 % SCLC and 8 % of LC. Tortuous blood vessels were significantly (p < 0.000) associated with SCC. Abrupt-ending vessels were identified in 81 % SCC, 14.3 % SCLC and 4.8 % adenocarcinoma and were significantly associated (p < 0.000) with SCC. Dotted visual pattern of blood vessels identified during NBI videobronchoscopy is highly suggesting adenocarcinoma histology of lung cancer. Tortuous and abrupt-ending blood vessels visualized under NBI videobronchoscopy significantly suggest squamous cell histology of lung cancer. Large-scale studies should be designed in order to determine true relation between visual appearance and histology in lung cancer.

BACKGROUND:The search for the most efficient bronchoscopic imaging tool in detection of early lung cancer is still active. The major aim of this study was to determine sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each bronchoscopic technique and their combination in detection of premalignant bronchial lesions.METHODS:This was a prospective trial that enrolled 96 patients with indication for bronchoscopy. Lesions were classified as visually positive if pathological fluorescence was observed under autofluorescence imaging (AFI) videobronchoscopy or dotted, tortuous, and abrupt-ending blood vessels were identified under narrow band imaging (NBI) videobronchoscopy. Squamous metaplasia, mild, moderate, or severe dysplasia, and carcinoma in situ (CIS) were regarded as histologically positive lesions.RESULTS:Sensitivity, specificity, PPV, and NPV of white light videobronchoscopy (WLB) in detection of premalignant lesions were 26.5%, 63.9%, 34.4%, and 54.9%, respectively; the corresponding values for AFI were 52%, 79.6%, 64.6%, and 69.9% respectively, for NBI were 66%, 84.6%, 75.4%, 77.7%, respectively, while the values for combination of NBI and AFI were 86.1%, 86.6%, 84.6%, and 88%, respectively. Combination of NBI and AFI significantly improves sensitivity when compared to each individual technique (P < 0.001). When specificity is of concern, combination of techniques improves specificity of WLB (P < 0.001) and specificity of AFI (P = 0.03), but it does not have significant influence on specificity of NBI (P = 0.53).CONCLUSION:Combination of NBI and AFI in detection of premalignant bronchial lesions increases both sensitivity and specificity of each technique. However, it seems that NBI is most sufficient and effective in detection of these lesions.

The role of autofluorescence bronchoscopy (AFB) was primarily investigated in regard to the detection of precancerous lesions of bronchial mucosa. Most of the results confirmed higher sensitivity for the detection of precancerous bronchial lesions, when compared to white light bronchoscopy (WLB) alone. However, it is commonly known that the specificity of AFB remains low. Our findings agree in terms of the detection of premalignant bronchial lesions and early lung cancer, but regarding the detection of synchronous lesions or in the evaluation of lung cancer extension, the specificity of AFB is significantly higher. There is still an ongoing debate in the scientific community whether or not autofluorescence should be used as a screening tool for lung cancer. Results of the majority of published series did not support the general use of AFB as a screening tool for lung cancer; however, these results suggest its use in groups of patients with a high risk of lung cancer. Despite this, some authors still do not recommend its use even in high-risk cases. In recent years, the indications for AFB have been widening and this tool may find its place in routine bronchoscopy. With new indications for AFB, such as the evaluation of tumor extension or follow up after surgical resection, bronchoscopists may make use of this tool more often. A sharp learning curve and a clear distinction between healthy and pathologically altered mucosa make this technology acceptable for inexperienced bronchoscopists. We also investigate new hardware and software improvements in AFB. The addition of backscattered light analysis, ultraviolet spectra, fluorescence-reflectance or dual digital systems could improve the diagnostic yield of this technology.