Computed tomographic angiography of a presumed acquired transhepatic portosystemic shunt in a miniature horse filly.
Abstract: A 1-year-old Miniature Horse filly was presented for chronic lethargy and hyporexia. Elevated liver enzymes, bile acids, and ammonia were noted on bloodwork. The primary differential diagnosis was a portosystemic shunt (PSS). Three-phase computed tomographic angiography findings were consistent with a transhepatic portosystemic shunt. Percutaneous liver biopsy confirmed severe diffuse hepatic changes, most likely due to chronic pyrrolizidine alkaloid toxicosis, and medical management was elected. Based on an extensive literature review, this is the first report of a transhepatic portosystemic collateral vessel in a horse. Computed tomographic angiography is feasible and useful for the diagnosis of PSS in miniature horses.
© 2024 American College of Veterinary Radiology.
Publication Date: 2024-06-28 PubMed ID: 38940068DOI: 10.1111/vru.13401Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Case Reports
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research study investigates a rare case of a transhepatic portosystemic shunt (T-PSS) in a miniature horse using computed tomographic angiography (CTA) thus demonstrating its applicability as a diagnostic tool in such cases.
Background & Purpose of the Study
- The study was prompted by the case of a 1-year-old Miniature Horse filly, which showed chronic fatigue and reduced appetite, commonly referred to as hyporexia.
- Bloodwork revealed elevated levels of liver enzymes, bile acids, and ammonia, which prompted the suspicion of a portosystemic shunt (PSS), a typically anomalous vascular connection between the systemic and portal venous circulation that can potentially bypass the liver.
- The objective of the study was to confirm this diagnosis and explore the severity, type of the shunt, and possible underlying causes.
Methods & Findings
- The research team employed a three-phase computed tomographic angiography (CTA) to conduct a closer examination of the presumed PSS. CTA is a medical imaging technique using contrast medium injected into the bloodstream to visualize vascular structures and tissues.
- The findings from the CTA were consistent with a transhepatic portosystemic shunt (T-PSS), a subtype of PSS where the shunting vessel crosses through the liver parenchyma.
- A subsequent percutaneous liver biopsy (a procedure performed to remove small pieces of liver tissue for examination) further confirmed severe diffuse hepatic changes, suggesting potential liver damage due to what was most likely chronic pyrrolizidine alkaloid toxicosis, which involves poisoning due to ingestion of plants containing harmful alkaloids.
Conclusion & Impact
- As confirmed from extensive literature review, this study becomes the first to report a case of transhepatic portosystemic collateral vessel in a horse.
- The study demonstrates that CTA is both feasible and useful as a diagnostic tool for detecting PSS in miniature horses, providing a new methodology in veterinary diagnostic approaches for similar cases.
- As such, the management of the horse’s health was adapted to medical treatment, moving towards a more accurate way to address this health issue.
Cite This Article
APA
Iranmanesh M, Sato AF, Tenney W, Brinker EJ, Cortez K, Mazan M.
(2024).
Computed tomographic angiography of a presumed acquired transhepatic portosystemic shunt in a miniature horse filly.
Vet Radiol Ultrasound, 65(5), 590-595.
https://doi.org/10.1111/vru.13401 Publication
Researcher Affiliations
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, USA.
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, USA.
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, USA.
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, USA.
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, USA.
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, USA.
MeSH Terms
- Animals
- Horses
- Horse Diseases / diagnostic imaging
- Computed Tomography Angiography / veterinary
- Female
- Liver / diagnostic imaging
- Diagnosis, Differential
- Portal System / abnormalities
- Portal System / diagnostic imaging
References
This article includes 17 references
- Woodford NS, Hotson Moore A, Renfrew H, Tulloch L, Casey M. Surgical management of an extrahepatic portosystemic shunt in a foal: a multidisciplinary problem. Equine Vet Educ 2017; 29(5):243‐248.
- Divers TJ, Perkins G. Urinary and hepatic disorders in neonatal foals. Clin Tech Equine Pract 2003; 2(1):67‐78.
- McAuliffe SB. Abdominal ultrasonography of the Foal. Clin Tech Equine Pract 2004; 3(3):308‐316.
- Gold JR. Portosystemic shunts: a diagnostic challenge. Equine Vet Educ 2017; 29(5):249‐251.
- Hug SA, Guerrero TG, Makara M. Diagnosis and surgical cellophane banding of an intrahepatic congenital portosystemic shunt in a foal. J Vet Int Med 2012; 26(1):171‐177.
- Fortier LA, Fubini SL, Flanders JA, Divers TJ. The diagnosis and surgical correction of congenital portosystemic vascular anomalies in two calves and two foals. Vet Surg 1996; 25(2):154‐160.
- Terpstra M, Gough SL, Parry AT. Presentation, stabilisation and contrast‐enhanced computed tomographic (CT) diagnosis of a left gastrocaval portosystemic shunt in a pony foal. Equine Vet Educ 2021; 33(8):.
- Willems DS, Kranenburg LC, Ensink JM, Kummeling A, Wijnberg ID, Veraa S. Computed tomography angiography of a congenital extrahepatic splenocaval shunt in a foal. Acta Vet Scand 2019; 61(1):39.
- Zwingenberger AL, Schwarz T, Saunders HM. Helical computed tomographic angiography of canine portosystemic shunts. Vet Radiol Ultrasound 2005; 46(1):27‐32.
- Nelson NC, Nelson LL. Anatomy of extrahepatic portosystemic shunts in dogs as determined by computed tomography angiography. Vet Radiol Ultrasound 2011; 52(5):498‐506.
- Bertolini G. Anomalies of the portal venous system in dogs and cats as seen on multidetector‐row computed tomography: an overview and systematization proposal. Vet Sci 2019; 6(1):10.
- Bertolini G. Acquired portal collateral circulation in the dog and cat. Vet Radiol Ultrasound 2010; 51(1):25‐33.
- Ibukuro K, Fukuda H, Tobe K, Akita K, Takeguchi T. The vascular anatomy of the ligaments of the liver: gross anatomy, imaging and clinical applications. Br J Radiol 2016; 89(1064):20150925.
- Ibukuro K, Tsukiyama T, Mori K, Inoue Y. Transhepatic portosystemic shunts: CT appearance and anatomic correlation. Am J Roentgenol 2000; 175(1):153‐157.
- Mirilas P, Skandalakis JE. Benign anatomical mistakes: right and left coronary ligaments. Am Surg 2002; 68(9):832‐835.
- Sharma M, Rameshbabu CS. Collateral pathways in portal hypertension. J Clin Exp Hepatol 2012; 2(4):338‐352.
- Cullen JM, Stalker MJ. Chapter 2: Liver and biliary system. 2016;258‐352. e251.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
