Lung Nodule Management

An Interventional Pulmonology Perspective

Udit Chaddha, MBBS; Jonathan S. Kurman, MD, MBA; Amit Mahajan, MD, FCCP; D. Kyle Hogarth, MD

Disclosures

Semin Respir Crit Care Med. 2018;39(6):661-666. 

In This Article

Virtual Bronchoscopy

VB is a noninvasive modality designed to assist with navigation to peripheral pulmonary nodules with flexible bronchoscopy. A three-dimensional (3D) reconstruction of the tracheobronchial tree from noncontrast high-resolution CT images of the chest simulates the view a bronchoscopist has during the procedure. Using specialized software, operators are able to perform a VB and identify the best endoluminal route to a lesion. The software can be used to preplan the procedure and also for intraprocedural guidance. Operators can manually advance along their route in the VB while simultaneously performing the actual flexible bronchoscopy. In this manner, navigation can be augmented by having a simultaneous synchronized virtual map of the airways. By using a slim or ultra-slim bronchoscope, operators are able to navigate out to several generations of airways under direct visualization using white light bronchoscopy. Once the target lesion is reached, tissue samples are obtained using standard tools such as biopsy forceps, needles, and brushes.

Studies have demonstrated that guided bronchoscopy techniques in general improve diagnostic yield compared to traditional TBBs. VB-guided yield rates range from 67 to 80%, based on trials from large centers with extensive expertise. A meta-analysis of 39 studies identified a diagnostic yield rate of 72% with VB, which was similar to those of the other guided techniques, including EMN, guide sheath, ultra-thin bronchoscopes, and r-EBUS.[27] In a study that accounted for the lesion size, the diagnostic yield decreased to 67.4% for lesions ≤2 cm.[28] The addition of fluoroscopy has also been shown to improve diagnostic yield with VB (85 [with] vs. 76% [without]).[29] Two randomized controlled trials of VB versus non-VB-guided procedures demonstrated conflicting results. While one demonstrated an increased diagnostic yield (80 vs. 67%), the other showed no significant difference (67 vs. 60%) with the addition of VB.[30,31] As with many of the other techniques, diagnostic yield will depend upon a multitude of factors, including the lesion size, location, operator expertise, and the use of other adjunctive technologies.

The most significant limitation is having to correlate the position of the actual bronchoscope with the virtual bronchoscope as synchronization is not automatic. Because there is no electromagnetic component, operators must rely on a side-by-side visual comparison of the actual and virtual bronchoscopic views. If these do not correlate, then the navigation process must be restarted from an easily identifiable position, such as the main carina. VB systems do not possess real-time tracking instruments. Another limitation is having to confirm localization of the target lesion. This step is typically accomplished using r-EBUS with or without a guide sheath and fluoroscopy. Despite these two limitations, VB is safe and introduces no additional risk to the procedure.

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