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Diagnostic Role of FOB in Radiological Hilar and Parahilar Shadow of Patients Reporting at Tertiary Care Centre

Fiberoptic bronchoscopy (FOB) is an important procedure for diagnosis of different respiratory problems. The present study was conducted to evaluate the diagnostic role of FOB in Hilar & Parahilar shadows and also to evaluate the value of bronchial Aspirate, brushing and biopsy in final diagnosis of various lung diseases. Study was carried out on 51 patients reporting the tertiary care centre of department. of T.B. and respiratory diseases, S.P. medical college, Bikaner, Rajasthan. Among the cases included in this study, 57% cases have both (Hilar & Parahilar) shadows at left side. Vocal cord paralysis was in 1/5 th (20%) cases. Endobronchial growth found in 59% cases. External compression was observed in 21.5% cases followed by inflammation in 15.6% and normal in 9.8% cases. Definite diagnostic yield of FOB for various lung diseases was 86%. Maximum cases (72%) diagnosed as lung cancer. Max. diagnostic yield in diagnosing lung cancer was through bronchial brushing (70%). Maximum diagnostic yield of procedure for malignancy was in bronchial biopsy (88%). Thus FOB technique has a high diagnostic yield in current clinical practice. Results suggested that the diagnostic yield of FOB of present study is as good as with studies performed by other centres within the country and abroad. This technique is more constructive in diagnosis when combined with a sound clinical judgment and other supportive investigations.


Introduction
Fiberoptic bronchoscope was first introduced by IKEDA S in 1964. Fiberoptic bronchoscopy (FOB) is a very useful and safe procedure for diagnosis of various respiratory diseases. It is a useful method for direct visualization of pathological changes in Trachea [1] , and if performed carefully, can be a thoroughly safe procedure [2] . Endobronchial biopsies, aspirate and brushing were performed for the diagnosis, which is useful in diagnosis of un-common infections, neoplasm and other non infectious causes. FOB not only helps in assessing the disease area but also provides better bacteriological and histological yield thus helping to reach a definite diagnosis. Thus FOB is immensely useful for making a conclusive diagnosis of lung cancer, especially when there is an endobronchial lesion, providing adequate tissue sample by endobronchial biopsy, endobronchial aspirate or brush cytology.       Hilar and Parahilar shadow in a middle & elderly person should be investigated by fiberoptic bronchoscopy to rule out malignant pathology.

Discussion
Development of the flexible FOB and various accessory instrument that can be inserted via the working channel has extended bronchoscopic exploration to the lung periphery. The instrument permits acquisition of tissue biopsy specimen, selective mucosal brushing, and broncheoalvoelar washings. Bronchoscopy is currently the primary means for diagnosis pulmonary malignancies [3] . In a normal person hilum shadows are caused by pulmonary artery and veins, and there is also a small contribution from airways and lymphnodes. The right hilum is opposite the horizontal fissure at the 6 th rib in the axilla or at the level of 3 rd rib anteriorly. On the left side centre of hilum is 1.0-1.5 cm higher than right.
In the present work diagnostic yield of FOB in lung diseases was 86% (51 cases) of patients whereas in the study conducted by Fein and Feinsilver [4] the FOB was diagnostic in 12 out of 14 (86%) patients. The study population was less as compared to present study.
Foos et al [5] observed the retrospective data of 616 bronchoscopy procedures and recorded 57% of diagnostic yield of FOB whereas the diagnostic yield of bronchoscopy for detection of malignancy was 66.6%. Foos et al [5] give the highest diagnostic yield of 92% in the cases with a macroscopically visible tumor, while another study [6] reported a diagnostic yield of 51% for peripheral lesions. Similarly, Anandan et al [7] also reported the highest yield in the diagnosis of malignancy by endobronchial biopsy (85%) followed by bronchial brushings (34%) and washings (12%). Wong and colleagues evaluated biopsy, brushings and washings in the diagnosis of lung cancer and the overall diagnostic yield of FOB were 98.1%, 61.5% and 58.5% for the endoscopically visible, endoscopically not visible and endoscopically not visible fluoroscopic guidance cases respectively [8] .
In our study, yield of special procedures was 88.88% and 78.26% for bronchial biopsy and brushing respectively. Recent era is looking at the role of fiberoptic bronchoscope beyond diagnosis in intensive care units for therapeutic interventions. It is useful for removal of thick tenacious secretions in patients with atelectasis on mechanical ventilation as well as for difficult endotracheal intubation [9] . Thus the morbidity due to bronchiectasis or destroyed lung which can occur due to untreated lobar or lung collapse can be avoided with early intervention [10] .

Conclusion
The diagnostic yield of FOB with routine and basic procedures like endobronchial biopsy, endobronchial aspirate and brush cytology is satisfactory at our tertiary care unit. Routine flexible bronchoscopytechnique continues to have a high diagnostic yield in current clinical practice in common lung conditions like pulmonary tuberculosis, lung cancer and pneumonia. Thus the FOB is more constructive in diagnosis when applied with a sound clinical ruling and suitable compassionate investigations.