Pulmonary artery and lung parenchymal growth following early versus delayed stent interventions in a swine pulmonary artery stenosis model.

Abstract

OBJECTIVES:

Compare lung parenchymal and pulmonary artery (PA) growth and hemodynamics following early and delayed PA stent interventions for treatment of unilateral branch PA stenosis (PAS) in swine.

BACKGROUND:

How the pulmonary circulation remodels in response to different durations of hypoperfusion and how much growth and function can be recovered with catheter directed interventions at differing time periods of lung development is not understood.

METHODS:

A total of 18 swine were assigned to four groups: Sham (n = 4), untreated left PAS (LPAS) (n = 4), early intervention (EI) (n = 5), and delayed intervention (DI) (n = 5). EI had left pulmonary artery (LPA) stenting at 5 weeks (6 kg) with redilation at 10 weeks. DI had stenting at 10 weeks. All underwent right heart catheterization, computed tomography, magnetic resonance imaging, and histology at 20 weeks (55 kg).

RESULTS:

EI decreased the extent of histologic changes in the left lung as DI had marked alveolar septal and bronchovascular abnormalities (p = .05 and p < .05 vs. sham) that were less prevalent in EI. EI also increased left lung volumes and alveolar counts compared to DI. EI and DI equally restored LPA pulsatility, R heart pressures, and distal LPA growth. EI and DI improved, but did not normalize LPA stenosis diameter (LPA/DAo ratio: Sham 1.27 ± 0.11 mm/mm, DI 0.88 ± 0.10 mm/mm, EI 1.01 ± 0.09 mm/mm) and pulmonary blood flow distributions (LPA-flow%: Sham 52 ± 5%, LPAS 7 ± 2%, DI 44 ± 3%, EI 40 ± 2%).

CONCLUSION:

In this surgically created PAS model, EI was associated with improved lung parenchymal development compared to DI. Longer durations of L lung hypoperfusion did not detrimentally affect PA growth and R heart hemodynamics. Functional and anatomical discrepancies persist despite successful stent interventions that warrant additional investigation.

• Authors: Ryan Pewowaruk, Joshua Hermsen, Cody Johnson, Alexandra Erdmann, Kevin Pettit, Scott Aesif, J Carter Ralphe, Christopher J Francois, Alejandro Roldán-Alzate, Luke Lamers
• Journal: Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions (Catheter Cardiovasc Interv) Vol. 96 Issue 7 Pg. 1454-1464 (12 2020) ISSN: 1522-726X [Electronic] United States
• PMID: 33063918 (Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural)
• Copyright: © 2020 Wiley Periodicals LLC.

Topics

• Animals
• Disease Models, Animal
• Endovascular Procedures (instrumentation)
• Hemodynamics
• Lung (blood supply, growth & development)
• Male
• Pulmonary Artery (growth & development)
• Stenosis, Pulmonary Artery (diagnostic imaging, physiopathology, therapy)
• Stents
• Sus scrofa
• Time Factors
• Time-to-Treatment