Surgical management of left-divisional intrahepatic portosystemic shunts: Outcome after partial ligation of, or ameroid ring constrictor placement on, the left hepatic vein in twenty-eight dogs (1995-2005)

Objectives - To evaluate outcome in dogs with left divisional intrahepatic portosystemic shunts (PSS) treated by partial ligation (PL) or ameroid ring constrictor (ARC) placement on the left hepatic vein. Design - Retrospective study. Animals - Dogs (n=28) with left divisional intrahepatic PSS. Methods - Retrieved data from medical records of dogs with left divisional intrahepatic PSS that had PL (n=17) or ARC (n=11) were signalment, history, clinical signs, preoperative blood work, portal pressure measurements, ARC size, complications and postoperative technetium scintigraphy. Outcome assessed by owner interview 6 months-10 years after surgery was classified as excellent, good or poor. Differences were tested by exact χ² test. Results - Major complications occurred in 3 dogs: coagulopathy (1 PL dog died), ascites (1 PL dog survived) and seizures (1 ARC dog died). Eight PL dogs had technetium portal scintigraphy; 1 dog was negative and 7 dogs positive for persistent shunting. Seven ARC dogs had scintigraphy; 4 dogs were negative and 3 positive for persistent shunting. In PL dogs, long-term clinical outcome was excellent (92%) or good (8%) whereas, in ARC dogs it was excellent (20%), good (50%) or poor (30%). This outcome difference between treatment groups was significant (P=.0012). Conclusion - Dogs treated by PL had significantly better long-term outcome compared with ARC treated dogs. Clinical Relevance - Based on these data, ARC placement on the left hepatic vein in dogs with left-divisional intrahepatic PSS cannot be recommended.