Localizing small lung lesions in video-assisted thoracoscopic surgery via radiofrequency identification marking

Yojiro Yutaka, Toshihiko Sato, Jitian Zhang, Koichi Matsushita, Hiroyuki Aiba, Yusuke Muranishi, Yasuto Sakaguchi, Teruya Komatsu, Fumitsugu Kojima, Tatsuo Nakamura, Hiroshi Date

To facilitate accurate localization of small lung lesions in thoracoscopic surgery, we employed a micro-radiofrequency identification tag designed to be delivered through the 2-mm working channel of a flexible bronchoscope. This report presents the results of preclinical studies of our novel localizing technique in a canine model. To evaluate functional placement, three types of tags [Group A, tag alone (n = 18); Group B, tag + resin anchor (n = 15); and Group C, tag + NiTi coil anchor (n = 15)] were bronchoscopically placed in subpleural areas and subsegmental bronchi via our new delivery device; tags were examined radiographically on days 0-7 and day 14. In addition, eight tags, which were placed at a mean depth of 13.3 mm (range 9-15.7 mm) from visceral pleura in bronchi with a mean diameter of 1.46 mm (range 0.9-2.3 mm), were recovered by partial lung resection under video-assisted thoracoscopic surgery using a 13.56-MHz wand-shaped probe with a 30-mm communication range. Peripheral airway placement: Group C had a significantly higher retention rate than the other two groups (retention rate at day 14: Group A, 11.1 %; Group B, 26.7 %; Group C, 100.0 %; P < 0.0001). Central airway placement: Overall retention rate was 73.3 % in Group C, and placement was possible in bronchi of up to 3.3 mm in diameter. Outcomes of partial resection: Tag recovery rate was 100 %, mean time required for tag detection was 10.8 s (range 8-15 s), and mean surgical margin from the delivered tag was 9.13 mm (range 6-13 mm). Radiofrequency identification marking enabled accurate localization with depth, which could ensure effective deep resection margins.