Clinical outcomes for 20 cats with congenital extrahepatic portosystemic shunts treated with ameroid constrictor ring attenuation (2002–2020)

Krysta E. A. Janas DVM, Karen M. Tobias DVM, MS, DACVS, Josep Aisa DVM, ECVS, EBVS

Background: Cats with congenital extrahepatic portosystemic shunts (EHPSS) treated with ameroid ring constrictor (ARC) attenuation have historically been reported as having poor outcome. The authors aimed to report the perioperative, short-term, and long-term outcomes for 20 cats that underwent this procedure at a single veterinary teaching hospital between 2002 and 2020.

Methods: The authors collected data from medical records, including signalment, history, physical examination, clinicopathologic testing, medications, diagnostic imaging, intraoperative findings, perioperative complications, and postoperative clinical outcomes. Long-term outcome was obtained from a standardized owner interview or medical records. Outcomes were graded as excellent, good, or poor based on the resolution of clinical signs and the need for medical management.

Results: Perioperative complications were reported in five cats out of 20, including blindness (two cats), ascites (one cat), head pressing (one cat), and seizures and death (one cat). Short-term clinical outcome was excellent in 14/18 cats, good in 2/18 cats, and poor in 2/18 cats that were available for follow up, and long term clinical outcome was excellent in 15/18, good in 1/18 cats, and poor in 2/18 cats that were available for follow up.

Imaging Findings: The imaging findings or shunt morphologies in the study can be summarized as follows:

• Scintigraphy: Performed on 19 cats, confirming portosystemic shunting in all. The median shunt fraction was 88.4%.

• CT Scans: Conducted on five cats, each confirming a single extrahepatic shunt. Two of these cats were diagnosed with left gastro-caval EHPSS.

• Ultrasound: Used to evaluate the urinary tract in 15 cats, revealing nephroliths in two cats, bladder sediment in six, and cystoliths in two. One cat had an echogenic cyst in the liver identified via a full abdominal ultrasound.

Limitations: The main limitations of this study were its retrospective nature, the small sample size, the variation in anesthetic and anticonvulsant protocols, the lack of consistent clinical and diagnostic evaluation at long-term follow up, and the loss of some cases to follow up over time.

Conclusions: The authors concluded that surgical attenuation of EHPSS with an ARC can result in resolution of clinical signs and biochemical abnormalities in the majority of cats. However, seizures may persist long term, despite normal bloodwork. They suggested that prospective, multiinstitutional collaborations are needed to further define outcome and risk factors for complications in cats undergoing gradual attenuation of EHPSS with ARCs.

Disclaimer: The summary generated in this email was created by an AI large language model. Therefore errors may occur. Reading the article is the best way to understand the scholarly work. The figure presented here remains the property of the publisher or author and subject to the applicable copyright agreement. It is reproduced here as an educational work. If you have any questions or concerns about the work presented here, reply to this email.