Respiration-Induced Displacements of Abdominal Aortic Branches-An MRI Study.

Introduction

The endovascular surgical approach provides a minimally invasive treatment of abdominal aortic aneurysms with less perioperative morbidity. This technique depends heavily on imaging to diagnose, plan surgical treatment, conduct the surgical procedure, and follow-up with patients. Image fusion technique was proposed to decrease radiation and injected contrast exposure; however, the accuracy of image fusion still needs to be improved. One of the major causes of this inaccuracy is the displacement of visceral arteries during respiration.

Objective

To analyze the physiological respiration-induced movements of the abdominal aortic side branches. Materials and

Methods

Thirty healthy volunteers were studied using noncontrast-enhanced MRI. Images were acquired in expiratory and inspiratory forced breath-holds. The displacements were studied by calculating 3-dimensional expiration-inspiration vectors of measured points; diaphragmatic domes, origins of the celiac trunk (CTA), superior mesenteric artery (SMA), right renal artery (RRA), and left renal artery (LRA) as well as the kidneys hila.

Results

For all measured points, the superior-inferior displacements were the most important component of movement vectors, and they were statistically significant. The right hemidiaphragm moved by 33.35 mm P < .001, the left hemidiaphragm by 32.4 mm P < .001, the right kidney moved by 19.56 mm P < .001, the left kidney moved by 23.64 mm P < .001, the origin of CTA moved by 3.41 mm P < .001, the origin of SMA moved by 3.54 mm P < .001, the origin of RRA moved by 3.03 mm P < .001, and the origin of moved LRA by 3.17 mm P < .001.

Conclusion

We found significant displacements of abdominal aortic branches from forced expiratory to forced inspiratory position. There is a positive correlation between diaphragmatic movement and all visceral arteries orifices displacements; however, this correlation is not high enough to be relayed upon for image fusion correction. Considering only the level of diaphragm to predict the level of abdominal branches origins is insufficient to correct image fusion inaccuracy. We suggest using a dynamic preoperative study as fusion model. Finally, this analysis protocol should be reapplied to a sample of patients with abdominal aneurysm to evaluate respiration-induced movements of the abdominal aortic side branches in pathological condition.Clinical ImpactAlthough it is known that visceral arteries move with respiration, the specific patterns and influencing factors remain unclear. No large-scale studies have quantified this motion under physiological conditions, and current understanding relies mainly on anatomical assumptions rather than detailed evidence.Understanding and predicting this movement has clear clinical implications. Accurate characterization of respiratory-induced arterial motion could improve image registration and fusion techniques, enhance navigation during endovascular or surgical interventions, and reduce errors related to motion artifacts. Ultimately, building predictive models of arterial dynamics may lead to safer procedures, more precise device deployment, and better patient outcomes.