Outcomes after extrahepatic portosystemic shunt ligation in 49 dogs

Objective To evaluate outcomes after attenuation of extrahepatic portosyste mic shunts in dogs using surgical silk. Design Retrospective study. Procedure Case records were reviewed for degree of surgical attenuation, ex perience of the primary surgeon, perioperative mortality and problems relat ed to persistent portosystemic shunting or shunt ligation. Presence of port osystemic shunting after surgery was evaluated by ammonia tolerance testing , measurement of postprandial serum bile acid, plasma urea and cholesterol concentrations and liver enzyme activity. The influence of age, postocclusi on portal pressure, primary surgeon, degree of attenuation and postoperativ e biochemical findings on the occurrence of post operative problems was ass essed. Results The mortality rate was 2.1%. Shunt attenuation was complete in 34% and partial in 66% of dogs. Portal hypertension necessitating ligature remo val was encountered in only one dog. Five dogs experienced neurological abn ormalities (seizures or ataxia), possibly as a manifestation of 'postligati on seizure syndrome'. Postoperative liver function was normal in 78% of dog s, including 70% with partial shunt attenuation. Experience of the surgeon was related positively to outcome after partial attenuation (P = 0.002). Po stoperative biochemical evidence of abnormal liver function was the most se nsitive predictor of recurrence of clinical signs referable to persistent p ortosystemic shunting. Conclusions In the hands of an experienced surgeon, surgical attenuation of single extrahepatic shunts was safe and effective, even in animals with pa rtial attenuation. Most dogs with biochemical evidence of persistent shunti ng suffer relapse of clinical signs within 18 months of surgery. Postligati on neurological syndromes of variable intensity may be more common than pre viously thought.