Electromagnetic catheter navigation during bronchoscopy - Validation of a novel method by conventional fluoroscopy

Background: Electromagnetic navigation in bronchoscopy is a novel method for assisting in the localization of peripheral lung lesions. Study objective: To assess the usability, accuracy, and safety of electromagnetic navigation during flexible bronchoscopy in a clinical setting. Design: Prospective evaluation. Patients: Consecutive patients referred to the bronchoscopy unit for the diagnosis of peripheral infiltrates or solitary pulmonary nodules (SPNs). Methods: Navigation was performed using an electromagnetic tracking system with a position sensor encapsulated in the tip of a flexible catheter that was pushed through the working channel of the bronchoscope. Real-time, multiplanar reconstruction of a previously acquired CT data set provided three-dimensional views for localization of the catheter. To match the position of the sensor with the CT scan, four anatomic landmarks were used for registration. The sensor position generated in the navigation system was controlled by fluoroscopy, and the corresponding error distances were measured. This was performed with all SPNs and at two different peripheral locations of the right upper lobe (RUL). Results: Sixteen patients (10 men and 6 women; mean age, 63.7 years) were studied. Navigation prolonged bronchoscopy by 3.9 +/- 1.3 min (mean +/- SD). The navigation system identified all lesions. The position sensor achieved a direct hit in three of five SPNs. Fluoroscopy failed to recognize three SPNs (60%) and three infiltrates (38%). The mean error distances between sensor tip position and fluoroscopically verified RUL reference position were 10.4 mm (lateral position) and 12.5 mm (apical position) respectively. The mean error distances between the sensor tip and two endobronchial registration points at the end of the procedure were 4.2 min and 5.1 mm, respectively. Conclusion: Electromagnetic navigation is useful, accurate, and safe in the localization of peripheral lung lesions and may help to improve the yield of diagnostic bronchoscopic procedures.