Post-mortem Computed Tomographic Angiography in Equine Distal Forelimbs: A Feasibility Study

Chantal Blaettler; Sabine Kaessmeyer; Silke Grabherr; Christoph Koch; Daniela Schweizer; Elke Van der Vekens

doi:10.3389/fvets.2022.868390

Post-mortem Computed Tomographic Angiography in Equine Distal Forelimbs: A Feasibility Study

Front Vet Sci. 2022 May 11:9:868390. doi: 10.3389/fvets.2022.868390. eCollection 2022.

Authors

Chantal Blaettler¹, Sabine Kaessmeyer², Silke Grabherr³, Christoph Koch⁴, Daniela Schweizer¹, Elke Van der Vekens¹

Affiliations

¹ Division of Clinical Radiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
² Division of Veterinary Anatomy, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
³ Centre Universitaire Roman (Lausanne-Geneva), University Centre of Legal Medicine (CURML), Lausanne, Switzerland.
⁴ Swiss Institute of Equine Medicine, Department of Clinical Veterinary Sciences, Vetsuisse Faculty, University of Bern, Bern, Switzerland.

Abstract

In-depth understanding of pathophysiological processes occurring in the vasculature of the equine distal limb is of great importance to improve both diagnostic and therapeutic approaches to diseases. To gain further insights, a model allowing high-resolution 3D-visualization of the vasculature is necessary. This pilot study evaluated the feasibility of restoring vascular perfusion in frozen-thawed distal equine cadaver limbs without prior preparation using computer tomographic imaging (CT). Five frozen-thawed, radiographically normal forelimbs were perfused with a lipophilic contrast agent through the median artery and radial vein in three phases (arterial, venous, and arterial-venous combined (AVC) dynamic). For comparison, one additional limb was perfused with a hydrosoluble contrast agent. The CT-studies (16-slice MDCT, 140 kV, 200 mA, 2 mm slice thickness, 1 mm increment, pitch 0.688) were evaluated at 11 specified regions for visualization of the vasculature and presence of artifacts or anatomic variations. The protocol used in this study proved to be feasible and provided good visualization (93.1%) of vasculature with low rates of artifacts. During the different phases, vascular visualization was similar, but while filling defects decreased in the later phases, extravasation worsened in the 2 limbs where it was observed. Subjectively, the best quality of angiographic images was achieved during the AVC dynamic phase. Perfusion with hydrosoluble contrast resulted in significantly lower vascular visualization (74.0%) and higher artifact rates. This study shows that reperfusion of frozen-thawed equine distal limbs with a lipophilic contrast agent allows for high-quality 3D-visualization of the vasculature and may serve as a model for in situ vascular evaluation in the future.

Keywords: PMCTA; cadaver; horse; perfusion; vascular anatomy.