Ultrasonography of Vascular Structures


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Ultrasonography of Vascular Structures


Rana Bozorgmanesh


The author acknowledges the prior contribution of Fairfield T. Bain
Hagyard Equine Medical Institute, Lexington, KY, USA


Jugular Vein


The jugular vein is often evaluated ultrasonographically, particularly when thrombophlebitis is suspected in horses with or without intravenous catheters in place. Early signs of thrombophlebitis can be detected ultrasonographically prior to any obvious external indication, including thickening of the wall and/or clot formation. Ultrasound examination of more advanced cases might show partial or complete blockage of the vein and abscess formation. Perivascular injection of medications may cause a local reaction including a focal cellulitis or abscessation (Figures 26.1, 26.2, 26.3, 26.4, 26.5, 26.6, 26.7, 26.8, 26.9, 26.10, 26.11, and 26.12). The jugular vein can be imaged along the neck from its entry into the thoracic inlet distally throughout its course to the bifurcation into the internal and external jugular vein branches just caudal to the ramus of the mandible. To facilitate evaluation, the jugular vein should be distended by occlusion distally near the thoracic inlet, and then the probe can be used to trace the vein along its course. Thorough evaluation involves imaging in both longitudinal and transverse planes. The author likes to scan from distal to proximal along the vein with particular focus on the region of concern (e.g., site of intravenous catheter insertion or palpable thickening of the vein or perivenous tissues).


Figure 26.1 Normal jugular vein. The normal jugular vein and its relation to the underlying carotid artery and esophagus varies along its course in the neck. This image shows the close approximation of the jugular vein (J) and carotid artery (C) in the distal third of the neck. The jugular vein is distended with some increasing echogenicity of the blood from stasis. The walls of this normal vein are thin and crisply echogenic. The normal musculature of the neck can be seen surrounding the vein and artery. This sonogram was obtained from the jugular groove with a linear probe operating at 7.5 MHz at a depth of 5 cm.


Figure 26.2 Occluded jugular vein. This image shows the jugular vein (J) occluded distally. Occlusion of the jugular vein will obstruct normal blood flow and swirling echogenicity of the normal blood will be observed during the first several seconds after occlusion. This sonogram was obtained from the jugular groove with a linear probe operating at 7.5 MHz at a depth of 5 cm.


Figure 26.3 Myositis near jugular vein. The main indication for imaging the jugular vein is concern for possible thrombosis. Clinical evaluation of the vein would include palpation of the vein along its course, both before and after distal occlusion. Some patients may have significant perivenous swelling or swelling along the jugular groove of the neck, and ultrasound can be useful to differentiate perivenous inflammation from actual jugular thrombosis or thrombophlebitis. This sonogram shows a central region of echogenicity (arrow) within the cervical muscles consistent with inflammation from intramuscular injection from attempted venous injection in a fractious horse. In this patient, the swelling in the neck was from the focal myositis rather than the jugular vein. This sonogram was obtained from the jugular groove with a linear probe operating at 7.5 MHz at a depth of 4 cm.


Figure 26.4 Intravenous catheter. Swelling, firmness, or thickening of the jugular vein associated with the presence of an intravenous catheter is one of the more common indications for ultrasound evaluation of the jugular vein. This patient with an intravenous catheter in place (arrow) has sonographic evidence of early phlebitis with thickening of the jugular vein wall (arrowheads). A venous valve (small arrow) is also seen in this image. This sonogram was obtained from the jugular groove with a linear probe operating at 7.5 MHz at a depth of 5 cm.


Figure 26.5

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Nov 6, 2022 | Posted by in EQUINE MEDICINE | Comments Off on Ultrasonography of Vascular Structures

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