CrossCountryTM transbronchial access tool (TBAT)
The CrossCountryTM TBAT (Medtronic) is designed to allow access through an airway wall and into the lung parenchyma, specifically for difficult to reach lesions, or to reach various areas of a larger lesion. Once the optimal airway exit point is reached, a small sharp tipped wire is deployed through the airway wall and into the parenchyma. Subsequently a cone-shaped dilator is advanced over the wire, through the airway wall and into the parenchyma to the target. Then by Seldinger technique, the extended working channel/EdgeTM catheter is advanced over the graduated dilator while pulling the wire back. The catheter is directed over the central dilator until in the correct position at the proximal edge of the lesion. The wire and dilator are then removed leaving access for biopsy tools though the extended working channel/EdgeTM catheter.
Two small case series have been published on the feasibility and safety of this device. In the first study, Anciano et al. described three cases utilizing the TBAT (11). The lesion was able to be reached in all three cases, 2 of which yielded a definitive diagnosis. There were no adverse events reported. In a second series, Bowling et al. reported their experience with the TBAT in 12 lesions (12). Seventy-five percent of these lesions (9 of 12) were able to be accessed successfully with the TBAT. The diagnostic yield was 66% (8 of 12) and one patient suffered a pneumothorax and required a chest tube. Perhaps most importantly, after the development of a specific protocol was instituted, the next 7 of 7 cases were successful. The protocol involved preprocedural CBCT scan (Artis Zeego, Siemens) and highlighting of the lesion with software so that if there was any small amount of bleeding around the lesion during biopsy or TBAT deployment, they would still know the position of the nodule. The second part of the protocol involved doing a repeat CBCT scan once the planned exit point was reached to confirm line to target and to avoid any “danger zones” (pleura, vessels, etc.). The use of the TBAT as well as CBCT may be integral to the future bronchoscopic application of ablative energy to a lung lesion.
