Intrasac pressure changes and vascular remodeling after endovascular repair of abdominal aortic aneurysms: Review and biomechanical model simulation

S. T. Kwon, J. E. Rectenwald, S. Baek

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

In this paper, we review existing clinical research data on post-endovascular repair (EVAR) intrasac pressure and relation with abdominal aortic aneurysm (AAA) size changes. Based on the review, we hypothesize that intrasac pressure has a significant impact on post-EVAR AAA size changes, and post-EVAR remodeling depends also on how the pressure has changed over a period of time. The previously developed model of an AAA based on a constrained mixture approach is extended to include vascular adaptation after EVAR using an idealized geometry. Computational simulation shows that the same mechanism of collagen stress-mediated remodeling in AAA expansion induces the aneurysm wall to shrink in a reduced sac-pressure after post-EVAR. Computational simulation suggests that the intrasac pressure of 60 mm Hg is a critical value. At this value, the AAA remains stable, while values above cause the AAA to expand and values below cause the AAA to shrink. There are, however, variations between individuals due to different cellular sensitivities in stress-mediated adaptation. Computer simulation also indicates that an initial decrease in intrasac pressure helps the AAA shrink even if the pressure increases after some time. The presented study suggests that biomechanics has a major effect on initial adaptation after EVAR and also illustrates the utility of a computational model of vascular growth and remodeling in predicting diameter changes during the progression and after the treatment of AAAs.

Original languageEnglish (US)
Article number011011
JournalJournal of Biomechanical Engineering
Volume133
Issue number1
DOIs
StatePublished - Dec 23 2011

Keywords

  • Constrained mixture model
  • Endoleak
  • Stress-mediated growth and remodeling
  • Vascular mechanics

ASJC Scopus subject areas

  • Biomedical Engineering
  • Physiology (medical)

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