B80-4-46 The Impact of Intermittent Apneic Ventilation on the Diagnostic Yield of Robotic Bronchoscopy Biopsies of Peripheral Pulmonary Lesions: A Pilot Study

Rationale

Robotic assisted bronchoscopy (RAB) and real-time integration of 3D mobile cone beam computed tomography (CBCT) imaging has improved both diagnostic yield and accuracy of peripheral pulmonary lesion (PPL) biopsies. Improvements in ventilation strategies to mitigate against the risk of computed tomography to body divergence (CTBD), the difference between the static planned target on preprocedural imaging and the dynamic PPL in the breathing patient, represents an area of continued interest. We recently employed an intermittent apneic strategy to allow for persistent utilization of corrected, real-time PPL target location with catheter and biopsy tool alignment. We present our results from this pilot study.

Methods

Patients undergoing RAB with intermitted apneic ventilation were assessed for demographic information, nodule characteristics, and procedural data. Diagnostic yield, using a strict definition, was the primary outcome. Secondary outcomes included change in end tidal CO2 from RAB start to end and periprocedural complications. Procedures were performed with 100% oxygen from induction to completion of RAB. After navigation to the target PPL, patients underwent apneic ventilation at end inspiration during their CBCT spin under a positive end expiratory pressure of at least 10cmH2O and with the adjustable pressure-limiting valve set to at least 20cmH2O. While the patient was breathing, real-time location of the target PPL was identified and integrated into the RAB system to allow for updated PPL positioning and adjustments in catheter-PPL relationship on the RAB system console graphical user interface (GUI). Apneic ventilation was then used as needed during biopsy attempts to ensure that the same biopsy tool and catheter relationship to the target PPL was visualized on the GUI.

Results

During the initial pilot period, 23 PPLs (21 patients, two patients with two PPLs each) were biopsied. Diagnostic yield was 96% (22/23, n = 15 malignancy, n = 4 granulomatous inflammation, n = 2 organizing pneumonia, n = 1 necrosis). Mean change in end tidal CO2 was 11+/-8mmHg (RAB start 39+/-4mmHg vs RAB peak 50+/-8mmHg). No patients experienced a cardiac abnormality during the bronchoscopy. Mean dose area product was 1688+/-1187 microGy*m2. Pneumothorax occurred in one patient with a pleural based PPL and required chest tube placement.

Conclusion

Employment of an intermittent apneic ventilation strategy after real-time mobile CBCT imaging integration and PPL location correction appears to be a safe and effective adjunct to allow for increasing accuracy of PPL biopsies. Further studies looking more broadly at this technique are indicated to ensure procedural safety and efficacy.

This abstract is funded by: None