Figure 1.

Localizing the nodule within the zone of negative staining using watershed analysis. (A) Preoperative computed tomography scan shows a pure ground-glass nodule (red arrow) located in the right upper lobe, about 7.5 cm from the lateral chest wall; (B) watershed analysis of segmental/subsegmental pulmonary arteries around the nodule was performed; (C) measuring the shortest distance between the lesion and the virtual cutting edge; (D) identifying the target artery intraoperatively; (E) the colored ribbon was used to ligate the target subsegmental artery with a slipknot; (F,G) Observation of the lung using an infrared thoracoscopy system after an intravenous injection of indocyanine green (2.5 mg/mL) and marking of the white-to-blue transitional zone by electrocautery; (H,I,J) to keep the margin at least 1 cm from the tumor, we performed an extended resection with a distance of 1.0 cm between the cutting edge and the marking; (K,L) wedge resection was performed successfully, and the lesion was confirmed.