Robotic-assisted bronchoscopy (RaB) has afforded proceduralists the ability to accurately
reach the periphery of the lung for biopsy of pulmonary nodules1. This has paved the way
for patients to undergo both biopsy of a peripheral nodule and a staging linear
endobronchial ultrasound (EBUS) in the same anesthesia event, promoting quicker
throughput from discovery of a lesion to guideline-adherent treatment2. Further,
introduction and mainstream utilization of cone-beam CT (CBCT) has provided the
bronchoscopist the ability to refine needle position with tool-in-lesion confirmation3.
While there are no randomized clinical trials promoting efficacy of RaB and CBCT in
comparison with other bronchoscopic methods, in single center retrospective studies,
diagnostic yield has consistently proven to be in the 70-85% range, superior to prior
technologies4-6.
One of the limitations of utilization of RaB and CBCT is the detrimental effect that
atelectasis plays in the bronchoscopy procedure. This can lead to false positive radial
EBUS (rEBUS) signals and non-diagnostic procedures7. This incidence of atelectasis has
been evaluated prospectively, using a protocol featuring 8-10 cmH2O of PEEP and limiting
hyperoxia8, and results suggest this ventilator strategy does an adequate job preventing
intraprocedural lung collapse. However, this study only evaluated incidence of
atelectasis and did not elaborate on its impact on diagnostic yield.
Further unknown is the optimal sequence of performance of RaB and a staging linear EBUS
in patients with a radiographically normal mediastinum. Starting with either the RaB or
Linear EBUS both have their pros and cons. The benefit to performance of a linear EBUS
first is the potential to obviate the need for peripheral nodule biopsy by obtaining
rapid, on-site pathologic feedback of occult nodal disease, reducing some of the risk of
the procedure (i.e. bleeding and pneumothorax).6 Conversely, the pitfalls to performing
linear EBUS first is the possible contribution of atelectasis resultant of the increased
time from intubation to peripheral nodule biopsy, blood in the airway causing
bronchospasm, and resorption atelectasis from hyperoxia9. There are no prospective data
evaluating this in a randomized fashion, but one Monte Carlo simulation (with assumption
of diagnostic yield from navigational bronchoscopy of 70% when performed first and 60%
when performed second) suggested a higher diagnostic yield and less need for repeat
procedure in the navigation first group, despite a 10% assumption of occult nodal
disease10.
As outlined in the specific aims above, the overarching goals of this study are to assess
in a multicenter, randomized clinical trial performed by members of the Interventional
Pulmonary Outcomes Group (IPOG), whether sequence of staging EBUS plays a role in
diagnostic yield, incidence of atelectasis, and safety outcomes in patients undergoing
RaB.