Aortic Morphologic Changes During Lethal Hemorrhage Characterized by Intravascular Ultrasound

Area of Science:

• Medical Imaging
• Surgical Research
• Trauma Medicine

Background:

• Noncompressible torso hemorrhage is a leading cause of potentially survivable battlefield death.
• Far-forward environments lack advanced imaging for rapid aortic injury localization.
• Intravascular ultrasound (IVUS) shows promise for identifying arterial injury and guiding hemorrhage control.

Purpose of the Study:

• To assess the utility of IVUS in quantifying aortic changes during induced hemorrhage.
• To establish physiologic parameters for IVUS-guided hemorrhage control.
• To inform the development of realistic hemorrhage simulation models.

Main Methods:

• Twenty swine underwent supraceliac aortic arteriotomy to induce lethal hemorrhage.
• IVUS was used pre- and post-injury to measure aortic diameter and cross-sectional area (CSA).
• Continuous hemodynamic data, including mean arterial pressure (MAP) and hemorrhage flow, were recorded.

Main Results:

• IVUS reliably measured aortic diameter and CSA changes during hemorrhage.
• Mean aortic diameter and CSA decreased significantly post-injury (16.4% and 28.7%, respectively).
• A strong linear association was found between MAP and aortic CSA (P < 0.001).

Conclusions:

• IVUS effectively detects aortic collapse during uncontrolled hemorrhage.
• A quantifiable, MAP-dependent relationship exists between vascular caliber and shock progression.
• Data provide parameters for hemorrhage interpretation and simulation model development.