Virtual-assisted lung mapping: outcome of 100 consecutive cases in a single institute

We developed virtual-assisted lung mapping (VAL-MAP), a bronchoscopic multispot dye-marking technique using three dimensional (3D) virtual imaging, for precise thoracoscopic sublobar lung resection with safe surgical margins. We herein review the results of 100 consecutive cases of VAL-MAP in our institute to identify types of tumours or resections that benefit from VAL-MAP.

Markings were bronchoscopically made within 2 days preoperatively using virtual 3D images. Post-VAL-MAP computer tomography (CT) scans localizing the actual markings were reconstructed into 3D images for intraoperative navigation. All data on patients, markings and outcomes were prospectively collected, and the contribution of VAL-MAP to the operation was graded by the surgeon.

Resections of 156 lung lesions in 100 consecutive patients were planned from July 2012 to March 2014. The lesion diameter was 8.3 ± 4.9 (range, 2-24) mm. The total number of actually conducted markings was 380 (3.83 ± 1.07 markings/patient). Eighty-four lesions were resected by 71 wedge resections using 158 markings (2.1 ± 0.1/resection; range, 1-3). Seventy lesions were resected by 63 segmentectomies using 224 markings (3.6 ± 0.1/resection; range, 2-6). Markings were identifiable on post-VAL-MAP CT mostly as ground-glass opacities (87.7%) and/or bronchial dilatation (56.1%). During the operation, 357 of 380 markings (93.9%) were visible on the pleural surface and significantly associated with marking visibility on CT. Multiple markings that were complementary to one another appeared to have contributed to the high rate of successful resection (99.3%) with satisfactory resection margins. The contribution of VAL-MAP to the operation as graded by surgeons demonstrated that VAL-MAP is most effective during wedge resection or complex segmentectomy for hardly palpable, small tumours, while VAL-MAP still plays an important role in simple segmentectomy or resection of palpable tumours by providing higher confidence levels to surgeons during the operation. Minor pneumothoraces were found on post-VAL-MAP CT images in 4 patients without symptoms or a need for treatment.

The present study further demonstrated the efficacy and safety of VAL-MAP. VAL-MAP is likely to benefit a broader range of patients than are conventional marking techniques by assisting with both accurate tumour identification and precise determination of resection lines.