Quantitative Relationship between Gain Factors and Growth Rate in the Growth and Remodeling Process of Abdominal Aortic Aneurysms

Abstract

Background: The homeostasis constrained mixture theory (HCMT) has significantly enhanced researchers’ comprehension of the growth and remodeling process of soft tissue. However, due to the intricate nature of computational models, adequately meeting the efficiency standards for predicting the growth of abdominal aortic aneurysm (AAA) remains challenging.

Objective: This study aims to establish the functional relationship between the growth rate of AAA and the associated growth parameters for rapid prediction of the changes in morphological, bio-mechanical parameters, and composition of AAA.

Methods: Leveraging the HCMT, we derived a set of optimal solutions for the growth parameters and the rate of change in maximum diameter of the AAA using follow-up data from the initial two time points encompassing 38 cases. The quantitative relationship between the growth rate of AAA and the gain factors controlling substance deposition was analyzed. Two distinct sets of AAAs with multiple follow-up time points and marked differences in growth rates were employed to validate the accuracy of the quantitative relationship.

Results: Through an inversion process of the growth parameters of 38 AAA patients, the function relationship between the gain factors and the growth rate was quantified by fitting with an exponential function. For the validation cases, the mean annual difference rates between the simulated diameter and the real-world diameter, derived from the follow-up data, were found to be within 1.5%, essentially meeting the clinical requirements for accurately predicting the maximum diameter growth of AAA.

Conclusion:  This study provides a quantitative analysis of the relationship between the growth rate and the gain factors, offering the potential to fulfill the accuracy and efficiency needs in predicting changes in AAA diameter. The findings hold promise for assisting in diagnostic and treatment decision-making processes.

Note:
Funding Information: None of the authors have any financial or scientific conflicts of interest about the research described in this manuscript.

Declaration of Interests: Program of Shanghai Academic Research Leader (No.19XD1401200).

Ethics Approval Statement: The collection of CTA image data in this study was conducted with the approval of the Ethics Committee of Zhongshan Hospital, Fudan University and informed consent forms were waived due to the retrospective study. (ethics number: 2021–042).

Keywords: Homeostasis Constrained Mixture Theory, Abdominal Aortic Aneurysm, Growth and Remodeling, Growth rates, Gain factor.