Bronchoscopy is frequently used as a diagnostic tool in patients with bronchiectasis in whom adequate or informative sputum cultures cannot be obtained [4,13]. However, there is little data regarding the role or diagnostic value of bronchial or lung biopsies in these patients.
In this study, we evaluate the common practice regarding bronchoscopy in subjects with bronchiectasis in our institute. We also assess whether the practice of performing lung biopsies or BAL cytology during bronchoscopy in patients with bronchiectasis is indeed indicated, and adds any clinical information for patient management. We found that performance of BAL cytology was almost universal and that EBB and/or TBB were commonly performed (60% of procedures). We however found that there is minimal or no added clinical benefit to BAL cytology or performing histological and/or microbiological evaluation of lung biopsies (either EBB or TBLB) over and above BAL cultures in non-CF bronchiectasis subjects.
These findings have important implications to clinical practice. Guidelines suggest sending BAL fluid microbiological analysis, including specific mycobacterial and fungal cultures [1,4]. As expected, and in concordance with previous studies [14-16], this practice proved to be most beneficial in our cohort with positive cultures obtained in nearly half the subjects, most of whom with negative previous sputum cultures. All the NTM positive cultures were new compared to previous sputum mycobacterial cultures, reinforcing the role of BAL in diagnosis of NTM.
Despite the importance of lung tissue cultures in aiding diagnosis of pulmonary NTM suggested by some , sending additional tissue cultures (performed in 27% of procedures in our cohort) did not result in any new clinically significant information except in one subject, making this practice seem not worthwhile.
Endo-bronchial biopsies were performed in our cohort in 40% of subjects. This was mostly performed in cases in which inspection of the airways revealed significant mucosal edema, bronchial narrowing or obstruction, findings commonly described in such subjects. Pathology reports is these cases were consistently non-specific, and showed mostly mucosal edema, basement membrane thickening, chronic and acute inflammation and goblet cell hyperplasia, findings that should be expected in subjects with chronic airway disease [18,19] but without clinical implications to date. Given these findings, and although this practice may seem warranted, our data shows that performing EBB in these subjects yields no clinically significant results, and does not alter patient management.
TBLB was also performed quite often in our cohort (30% of cases), with the aims of obtaining tissue cultures, pathology specimens for diagnosis of mycobacterial infections (as per the NTM diagnosis guidelines) , and perhaps an underlying unexpected diagnosis. In a retrospective study by Ikedo, the practice of performing TBLB in subjects with MAC yielded specific histology in 37%, specifically epithelioid cell granuloma and/or acid-fast bacilli, however this did not add to bronchial washing cultures . In our cohort, as with the case of EBB, TBLB did not result in any added benefit concerning diagnosis of NTM or TB, nor unravel any new underlying etiologies for bronchiectasis. One subject in our cohort was diagnosed with metastatic breast cancer following TBLB; however, these were performed regardless of the diagnosis of bronchiectasis.
Finally, the practice of performing lung biopsies comes at a price. We found an 8% risk of pneumothorax in our subjects undergoing TBLB (three cases) and two cases of significant bleeding. Although our numbers are small, there may be an increased risk of complications following transbronchial biopsies in patients with bronchiectasis compared to other patient groups as frequency of complications for TBLB is usually reported to be as low as 0-4% of procedures .
Limitations of our study include its retrospective design, and the single center data, that may not be applicable to other centers or regions in the world. However, we believe that the findings reported here are important for the decision making process undertaken with each bronchoscopy performed for patients with bronchiectasis.
Another limitation to our study may be the relatively low prevalence of mycobacterial disease in Israel [22,23]. Hypothetically, biopsies may be of greatest benefit in patients with suspected tuberculosis or NTM. Thus, biopsies may be of value in regions of the world with higher prevalence of mycobacterial disease and this may warrant analysis of similar data from other geographical regions.
In conclusion, we found that performing TBLB, EBB or cytology analysis of BAL fluid did not result in any significant additional clinical data when performing bronchoscopies in subjects with non-CF bronchiectasis. We recommend these practices be routinely avoided in such procedures, which should include performing bronchial inspection and BAL for microbiology alone.