Feasibility of navigated bronchoscopy- an experimetal animal model

Abstract

Feasibility of navigated bronchoscopy - an experimental animal model

Leira HO, Langø T, Tangen GA, Manstad-Hulaas F, Amundsen T

Background
Videobronchoscopy has a number of limitations in diagnosis of pulmonary lesions, and directly inspects the airways. The bronchoscopist has to rely on x-ray or CT imaging, fluoroscopy guided manouvers, and often blind biopsies alone.

Purpose
We are developing a 3D navigation system where the main goal is to improve targeting of lesions and thereby move from blind biopsies, repeated examinations and time consuming procedures to one navigated bronchoscopic procedure, providing earlier and more accurate diagnostic biopsies.

Method
The navigation system is a research platform based on electromagnetic tracking, navigation and visualization technology. The electromagnetic tracking data is combined with CT images, in which the position of the bronchoscope, biopsy equipment and lung lesions are presented in real-time to the bronchoscopist. The movement of the bronchoscope is followed in volume rendering view or orthogonal slices selected from the images by the position and orientation of the bronchoscope tip. Our set-up was designed to evaluate feasibility and accuracy of navigated bronchoscopy. The 30kg-pig-model closely resemble the human lung anatomy.

Results
An electromagnetic receiver positioned in a lower lung segment tracked the movements caused by respiration. In the second experiment, four different pellet-like foreign objects (plastic, glass, wood, and a silver ring) were placed in different lung locations. Two of them (metal-ring and glass-pellet) were easily located in CT images. Using the navigation platform, the images and position of the foreign objects could be demonstrated. Using electromagnetic guiding, the bronchoscopist was able to steer a tracked probe to the foreign objects and subsequently remove them.

Conclusions
Navigated videobronchoscopy yield high diagnostic accuracy, and combined with advanced visualization methods it seems to serve as a valuable tool for accurate diagnostic investigation and research purposes.