ATS 2021 will feature presentations of original research from accepted abstracts. Mini Symposia and Thematic Poster Sessions are abstract based sessions.
Please use the form below to browse scientific abstracts and case reports accepted for ATS 2021. Abstracts presented at the ATS 2021 will be published in the Online Abstract Issue of the American Journal of Respiratory and Critical Care Medicine, Volume 203, May 3, 2021.
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Monitoring Patients with Endobronchial Valve Interventions Using a Multifaceted Hyperpolarized (HP) Xenon Lung Function Assessment
Session Title
TP121 - TP121 COPD: FROM CELLS TO THE CLINIC
Abstract
A4578 - Monitoring Patients with Endobronchial Valve Interventions Using a Multifaceted Hyperpolarized (HP) Xenon Lung Function Assessment
Author Block: H. Hamedani, S. Kdlecek, F. Amzajerdian, R. Baron, K. Ruppert, Y. Xin, L. Loza, T. S. Achekzai, M. Cereda, K. C. Ma, D. Dibardino, I. Duncan, R. R. Rizi; University of Pennsylvania, Philadelphia, PA, United States.
Introduction: Zephyr Endobronchial Valves (Zephyr EBV, Pulmonx), small duckbill-shaped valves inserted into the lung’s distal airways to occlude an emphysematous target lobe, are a promising FDA-approved therapy for COPD1. We present an approach for comprehensively assessing the lung’s response to EBV insertion. Using our multi-breath approach during tidal breathing, we can evaluate whether ventilation is successfully redistributed to the healthier lung, and whether this shift in ventilation can effectively improve gas exchange in non-targeted lobes.
Methods: We previously introduced a multi-breath imaging scheme in which subjects inhale/exhale freely while HP gas is injected into a breathing line2. Figure 1A depicts this protocol schematically: subjects breathe through a mouthpiece, while a constant 50-100 mL of HP-Xe or air is injected into the line right before inhalation. 6 ad libitum normoxic wash-in breaths of hyperpolarized gas are followed by 4 washout breaths of room air; this ten-breath wash-in/washout series is repeated five more times with additional series encoding gas dissolution and uptake using the Xenon polarization Transfer Contrast (XTC).HXe images were co-registered with an affine transformation and added together to produce a lung atlas. The lobar estimation was derived using a general-purpose registration framework summarized in Figure 1B. For HXe, anatomical 1H MRI to CT-MR registration is used first; lobar EE CT segmentation is then applied to all warped images to yield lobar totals of regional minute and residual volumes (TV, FRC). We define the gas exchange rate in terms of the rate at which inverted spins re-enter the gas phase during the time (XTC), TR, between saturation pulses.
Results: Figure 1C shows functional maps, and Figure 1D graphically represents regional TV and in an EBV recipient pre- and post-intervention (compared a healthy subject). A distinctive pattern of near-normal gas exchange exists between the alveolar gas and capillary blood in the dorsal and right ventral lung, with reduced exchange in the central lung. Gas exchange is doubled in the upper left lobe, exceeding the modest ventilation increase observed after occlusion of the LL lobe, likely indicating dramatically improved perfusion. Notably, right lung function is also improved, perhaps due to normalized breathing mechanics.
Conclusion: This ongoing study aims to gain a fundamental, quantitative understanding of EBV intervention’s functional success and correlate this with subjective quality of life gains. Thus far, we have demonstrated obvious functional improvement in one subject who has completed both pre- and post-intervention imaging.
Author Block: H. Hamedani, S. Kdlecek, F. Amzajerdian, R. Baron, K. Ruppert, Y. Xin, L. Loza, T. S. Achekzai, M. Cereda, K. C. Ma, D. Dibardino, I. Duncan, R. R. Rizi; University of Pennsylvania, Philadelphia, PA, United States.
Introduction: Zephyr Endobronchial Valves (Zephyr EBV, Pulmonx), small duckbill-shaped valves inserted into the lung’s distal airways to occlude an emphysematous target lobe, are a promising FDA-approved therapy for COPD1. We present an approach for comprehensively assessing the lung’s response to EBV insertion. Using our multi-breath approach during tidal breathing, we can evaluate whether ventilation is successfully redistributed to the healthier lung, and whether this shift in ventilation can effectively improve gas exchange in non-targeted lobes.
Methods: We previously introduced a multi-breath imaging scheme in which subjects inhale/exhale freely while HP gas is injected into a breathing line2. Figure 1A depicts this protocol schematically: subjects breathe through a mouthpiece, while a constant 50-100 mL of HP-Xe or air is injected into the line right before inhalation. 6 ad libitum normoxic wash-in breaths of hyperpolarized gas are followed by 4 washout breaths of room air; this ten-breath wash-in/washout series is repeated five more times with additional series encoding gas dissolution and uptake using the Xenon polarization Transfer Contrast (XTC).HXe images were co-registered with an affine transformation and added together to produce a lung atlas. The lobar estimation was derived using a general-purpose registration framework summarized in Figure 1B. For HXe, anatomical 1H MRI to CT-MR registration is used first; lobar EE CT segmentation is then applied to all warped images to yield lobar totals of regional minute and residual volumes (TV, FRC). We define the gas exchange rate in terms of the rate at which inverted spins re-enter the gas phase during the time (XTC), TR, between saturation pulses.
Results: Figure 1C shows functional maps, and Figure 1D graphically represents regional TV and in an EBV recipient pre- and post-intervention (compared a healthy subject). A distinctive pattern of near-normal gas exchange exists between the alveolar gas and capillary blood in the dorsal and right ventral lung, with reduced exchange in the central lung. Gas exchange is doubled in the upper left lobe, exceeding the modest ventilation increase observed after occlusion of the LL lobe, likely indicating dramatically improved perfusion. Notably, right lung function is also improved, perhaps due to normalized breathing mechanics.
Conclusion: This ongoing study aims to gain a fundamental, quantitative understanding of EBV intervention’s functional success and correlate this with subjective quality of life gains. Thus far, we have demonstrated obvious functional improvement in one subject who has completed both pre- and post-intervention imaging.
