Number of dye marks required in virtual-assisted lung mapping

Virtual-assisted lung mapping is a preoperative bronchoscopic multi-spot dye-marking technique used in sublobar lung resection for hardly palpable lung nodules. However, the number of marks required per nodule remains unknown. Therefore, we examined the correlation between the number of intraoperative visible marks and the successful resection rate.

We retrospectively examined 210 consecutive patients with 256 lesions who underwent virtual-assisted lung mapping during January 2014-December 2020 at our hospital. When a nodule was not resected at the initial attempt, or when a nodule was very close to the cut margin in the resected specimen and required additional resection, we categorized it as unsuccessful resection. We divided 256 lesions into successful and unsuccessful groups and compared the numbers of intraoperative visible marks between the two groups.

Of 797 attempted marks, 738 (92.4%) were visible during the surgery. Fourteen (5.4%) of 256 lesions were determined to be unsuccessful according to the study criteria. There was a remarkable difference in the average numbers of intraoperative visible marks between both groups (3 [interquartile range: 2-4] vs. 2 [interquartile range: 1-2.8]; p < 0.01). Multivariable logistic analysis revealed a significant difference in the number of intraoperative visible marks (odds ratio: 0.28, 95% confidence interval: 0.14-0.57; p < 0.001) between both groups.

Successful sublobar lung resection requires three or more intraoperative visible marks established using virtual-assisted lung mapping per lung nodule.