Management of lung nodules newly found by virtual-assisted lung mapping: a case report

Preoperative lung surface localization for pulmonary wedge resection: a single-center experience

Background

Preoperative lung surface localization is effective in sublobar resection for small lung nodules. However, the efficacy may vary depending on the underlying conditions of the lung and tumor, as well as the technique. This study aimed to evaluate the efficacy and limitations of preoperative lung surface localization for wedge resection by analyzing the outcomes of computed tomography (CT)-guided percutaneous marking and virtual-assisted lung mapping (VAL-MAP).

Methods

We investigated 215 patients who underwent curative wedge resection for malignant tumors using CT-guided localization or VAL-MAP from 1998 to 2018 in our institute. Each resected nodule was assessed for successful resection, which was defined as complete resection with adequate margins.

Results

One-hundred-and-nineteen patients with 153 nodules were included. The overall successful resection rate was 87.6%. The successful resection rate was significantly lower for nodules with intraoperative adhesion than those without intraoperative adhesion (75.0% vs. 90.1%; P=0.034), and for tumors requiring deep resection margins (>31 mm) than those requiring shallow margins (≤31 mm) (76.7% vs. 94.6%; P=0.002). Although the successful resection rate for nodules resected using CT-guided localization was significantly lower in cases with versus without intraoperative adhesion (54.5% vs. 86.7%; P=0.048), the successful resection rate for nodules resected using VAL-MAP was not influenced by the presence or absence of adhesion (85.7% vs. 93.4%; P=0.491).

Conclusions

A requirement for deeper resection and the presence of intraoperative adhesion were limitations of preoperative lung surface localization for curative pulmonary wedge resection.

Effect of patient position during virtual-assisted lung mapping

Background

Virtual-assisted lung mapping (VAL-MAP) is a preoperative multi-spot bronchoscopic dye-marking technique. Marking failure reportedly occurs in approximately 10% of marks. The aim of the present study was to investigate whether the patient position during dye injection in VAL-MAP affected the quality of markings.

Methods

This study was a retrospective review of patients with barely palpable pulmonary nodules who underwent VAL-MAP at a single institution between December 2016 and September 2017. Easily visible markings without bulla formation were defined as "appropriate", while other markings were defined as "inappropriate". Patients were divided in accordance with the position during dye injection into the supine position group (n=6) and the lateral position group (n=8). The two groups were compared regarding the appropriate markings rate. The Fisher exact test and logistic regression model were used for statistical analyses.

Results

Fourteen patients with 17 nodules underwent VAL-MAP with a total of 48 markings (3.4±0.9 markings per patient). Of these, 21 markings were performed in supine position, whereas 27 were performed in lateral position. There were no significant differences between the two groups in lesion size, depth, and characteristics. Almost all of the performed procedures were thoracoscopic wedge resections (94%), while one procedure was thoracoscopic left upper division segmentectomy. The appropriate markings rate was significantly greater in the lateral position group than in the supine position group (88% vs. 57%, P=0.02). Among the markings located in dorsal and ventral lung segments, the appropriate markings rate in the lateral position group tended to be greater than that in the supine position group (89% vs. 59%, P=0.06). Multivariate logistic regression analysis revealed that the lateral position was independently associated with appropriate markings (P=0.014).

Conclusions

The lateral position may enable the creation of better quality markings in VAL-MAP.

Latest update about virtual-assisted lung mapping in thoracic surgery

Virtual-assisted lung mapping (VAL-MAP) is a preoperative bronchoscopic multi-spot dye-marking technique using virtual images developed to assist in navigational lung resection. The technique of VAL-MAP has been shown to be safe and effective surgical assistive tool for performing pulmonary sublobar resections. The technique is applicable for treating multiple small pulmonary lesions that are hardly palpable including ground glass nodules (GGNs). It also may help shorten surgical duration in wedge resection cases. Electromagnetic navigation bronchoscopy (ENB) may eliminate the need for post-mapping computed tomography (CT) scans in logistically challenged situations. In the most recent, multicenter prospective single-arm study, conventional VAL-MAP had reasonable efficacy for obtaining good surgical margin in pulmonary sublobar resections, although the successful resection rate did not reach the primary goal most significantly due to deep resection margins. The technique of VAL-MAP in combination with microcoil may be the next step to acquire better surgical margins.