CT findings after lipiodol marking performed before video-assisted thoracoscopic surgery for small pulmonary nodules

In preoperative lipiodol marking for small pulmonary nodules, lipiodol has a potential risk of distribution in the surrounding lung structure. There are no reports about the detailed accumulation and distribution of lipiodol.

To evaluate computed tomography (CT) findings after lipiodol marking before thoracoscopic surgery for pulmonary nodules.

Sixty-four consecutive CT-guided lipiodol markings for 103 nodules were performed in 55 patients. Lipiodol (0.2-0.4 mL) was injected using a 21-gauge needle near the nodule. The appearance of lipiodol spots was classified into the following three types on CT: type 1, dense; type 2, punctate; and type 3, unclear. The distribution of lipiodol was also investigated. Statistical analyses were performed on the accumulation and distribution related to nodule factors. Incidences of complications were also investigated.

A total of 110 markings were performed because of seven additional procedures due to insufficient marking. All nodules were successfully resected on the same day. The appearances of the lipiodol spots were type 1 (82%), type 2 (11%), and type 3 (7.3%). The areas of distribution were lung parenchyma (54%), central bronchus (39%), peripheral bronchovascular bundle (24%), needle tract (20%), pleural space (19%), another segment of ipsilateral lung (5.5%), and contralateral lung (0.9%). Distribution into pleural space and central bronchus was frequently seen in the shallow nodules (P < 0.05). Complications were pneumothorax (61%) and pulmonary hemorrhage (35%). There were no serious symptoms.

The appearance of the lipiodol spot was dense in most cases, despite frequent distribution in the surrounding lung structures without serious complications.