PURPOSE: Electromagnetic navigational bronchoscopy(EMNB) is a new technology used to improve diagnostic yield of peripheral lung nodules via navigation through peripheral airways. The end result of a successful navigation is an extended working channel leading through the bronchoscope and airways to the target nodule, through which biopsies are performed. Current biopsy instruments have been designed for either large proximal airways(endobronchial masses, TBNA) or lung parenchyma(TBBx); no biopsy tool has been developed specifically for peripheral nodules accessed via the airway. Recognizing the implications of an increased yield with a positive “bronchus sign”, the purpose of this study was to analyze the relationship between peripheral lung nodules and whether an airway running through it impacts yield of EMNB using current diagnostic tools.
METHODS: All procedures at three different centers undergoing diagnostic EMNB for peripheral nodules from September 2004 until October 2006 were analyzed. Using multiplanar high resolution CT-imaging, each nodule was defined by size, location, and whether or not it had an airway leading into it. Standard biopsy instruments were used (forceps, needle, or brush) and all cases were done with fluoroscopy. Procedure yield was determined by the presence of a definitive diagnosis.
RESULTS: There were 171 nodules in 126 patients that were analyzed. The average nodule size was 21.1+/-10.3mm. There were 120 nodules with an airway leading into it, a positive “bronchus sign” (Type A); 51 nodules did not have an associated airway (Type B). Diagnostic yield for Type A was 76.7%, and Type B 60.8%, which was statistically significant(p<0.05).
CONCLUSION: These results suggest that the presence of an associated airway to or within a nodule significantly increases the yield of EMNB. If a nodule is extrinsic to a small airway, despite advanced navigation techniques, current biopsy instruments may not enable adequate tissue sampling.
CLINICAL IMPLICATIONS: Current bronchoscopic biopsy instruments may not have the proper engineered design to adequately sample small peripheral nodules via EMNB. Development of EMNB-specific biopsy tools may improve yield in nodules without an associated airway leading into them.
DISCLOSURE: Joseph Cicenia, No Financial Disclosure Information; No Product/Research Disclosure Information