Effect of patient position during virtual-assisted lung mapping

Ten-Year Outcome and Development of Virtual-Assisted Lung Mapping in Thoracic Surgery

Virtual-assisted lung mapping (VAL-MAP) is a preoperative bronchoscopic multispot dye-marking technique used in sublobar lung resection of barely palpable lung nodules. This review summarizes the history and outcomes of the VAL-MAP procedure. VAL-MAP was developed in 2012, and long-term outcomes of lung resection using VAL-MAP have recently been verified. Problems associated with conventional VAL-MAP include a prerequisite of post-mapping computed tomography (CT), occasional inability to see dye marks during surgery, and infrequent resection failure due to deep resection margins; various techniques have been developed to address these issues. VAL-MAP using electromagnetic navigation bronchoscopy with on-site adjustment can omit post-mapping CT. The use of indocyanine green in VAL-MAP has increased the success rate of marking detection during surgery without causing additional complications. VAL-MAP 2.0—a three-dimensional mapping technique that involves the intrabronchial placement of a microcoil—has increased the accuracy of sublobar resection, particularly for deeply located tumors. Although these promising new techniques have some limitations, they are beneficial for sublobar lung resection.

Risk factors for invisible intraoperative markings after virtual-assisted lung mapping

BACKGROUND

Virtual-assisted lung mapping (VAL-MAP) is a preoperative bronchoscopic multi-spot dye-marking technique, which can be combined with bronchoscopic placement of a microcoil (VAL-MAP 2.0). VAL-MAP can identify unpalpable pulmonary lesions; however, the markings are occasionally deemed invisible intraoperatively. We investigated preoperative risk factors for invisible markings after VAL-MAP.

METHODS

We prospectively performed preoperative VAL-MAP in patients at the University of Tokyo between January 2014 and June 2020. Data of 219 patients (257 lesions) and 857 markings were retrospectively reviewed. Dye markings were categorized as Grade 0 (invisible) or 1-5 (visible). The risk factors for Grade 0 markings were assessed using multiple logistic regression analysis. Subsegments of the bronchus showing Grade 0 markings were also evaluated for 133 lesions and 504 markings without missing data for the target segment.

RESULTS

Sixty-one of the 257 lesions (24%) displayed >1 Grade 0 markings. Seventy-six (8.9%) of the 857 markings were Grade 0 intraoperatively. VAL-MAP 1.0 was performed for 202 (79%) and 25 lesions (10%) without and with electromagnetic navigation bronchoscopy, and VAL-MAP 2.0 with a microcoil was performed for 30 lesions (11%). Upper lobe markings were associated with a significantly increased risk of invisible markings. There was no significant difference in the frequency of Grade 0 markings among the VAL-MAP methods. Among all bronchi subsegments, left B1+2c exhibited the highest rate of Grade 0 markings.

CONCLUSIONS

Markings placed using VAL-MAP are more likely to be invisible for upper lobe pulmonary lesions. Injecting markings for lesions in the left S1+2c thus require caution.

Localization of Small Pulmonary Nodules Using Augmented Fluoroscopic Bronchoscopy: Experience from 100 Consecutive Cases

BACKGROUND

We developed augmented fluoroscopic bronchoscopy (AFB) for the localization of small pulmonary nodules. Here, we review the results of 100 consecutive cases of AFB localization performed in our institute in order to evaluate its efficacy, safety, and procedural details.

METHODS

This study was a retrospective analysis of prospectively collected data. Between July 2018 and September 2019, a total of 100 patients with 124 small lung nodules underwent AFB localization with dye marking and/or microcoil placement. All localizations were performed in a cone-beam computed tomography examination room followed by thoracoscopic resection within 3 days.

RESULTS

The mean nodule size was 9.7 mm, and the mean distance from the pleural space was 18.6 mm. Sixty-three patients received dye marking only, and 37 patients received microcoil placement with/without additional dye marking. The mean bronchoscopy duration was 10.4 min, and the mean fluoroscopy duration was 3.4 min. The mean radiation exposure (expressed as the dose-area product) was 3140.8 μGy × m². The AFB procedures were successful in 94 patients [augmented fluoroscopy discrepancy (n = 2), incomplete C-arm confirmation (n = 3), microcoil unlooping (n = 1)]; of those, 91 received successful marker-guided resection [invisible dye (n = 2), failed nodule resection with first wedge (n = 1)]. The mean length of postoperative stay and chest drainage was 4.2 and 2.9 days, respectively.

CONCLUSIONS

The AFB technique is a safe and reproducible alternative for localizing small pulmonary nodules, and various localization strategies can be implemented for different nodule locations and resection plans.

Hybrid technique of virtual-assisted lung mapping and systemic indocyanine green injection for extended segmentectomy

BACKGROUND

Various approaches have been used to assist and facilitate segmentectomy with favorable oncological outcomes. We describe a hybrid approach comprising virtual-assisted lung mapping (VAL-MAP), which is a preoperative bronchoscopic dye-marking technique, combined with systemic indocyanine green (ICG) injection.

CLINICAL PRESENTATION

An asymptomatic 64-year-old man was referred to our department because of a lung nodule detected during his annual medical checkup. The chest computed-tomography image revealed a 16-mm, partly solid, ground-glass nodule in the left segment 4. Because the nodule was hardly palpable and deeply located between the left upper division segment and the left lingular segment, we performed VAL-MAP to facilitate extended left lingulectomy. Five dye markings were undertaken preoperatively. Surgery to remove the nodule was then conducted via complete three-port video-assisted thoracic surgery. The VAL-MAP markings were easily identified intraoperatively and helped locate the nodule. The intersegmental plane was identified by the ICG injection. The resection line was determined based on the intersegmental plane identified by the ICG injection and the site of the nodule suggested by the VAL-MAP markings. Following the resection line, we thoracoscopically achieved extended lingulectomy with sufficient surgical margins. The patient was discharged with no complications. The pathological diagnosis was adenocarcinoma in situ.

CONCLUSION

The hybrid technique of VAL-MAP and systemic ICG injection can be useful for accomplishing successful extended segmentectomy.

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.