Long-Term Outcome after Surgical Ameroid Ring Constrictor Placement for Treatment of Single Extrahepatic Portosystemic Shunts in Dogs

ObjectiveTo report long-term clinical outcome in dogs treated for single congenital extrahepatic portosystemic shunt (CEHPSS) with a ameroid ring constrictor (ARC) and to identify perioperative variables associated with outcome.Study DesignRetrospective, multi-institutional study.AnimalsDogs (n=206) with CEHPSS.MethodsMedical records of dogs with CEHPSS treated by ARC were reviewed for perioperative and short-term (<1 month) data. Long-term follow-up information was obtained by telephone interview with referring veterinarians and/or owners. Kaplan-Meier analysis was used to estimate median survival time. Factors associated with short-term survival, outcome grade, and total survival time were identified.ResultsFifteen dogs died <1 month after ARC placement. Follow-up data were obtained for 112 of 191 dogs that survived >1 month; median follow was 54 months (range, 1-175 months) and 103 (92%) dogs had no clinical signs. Estimated median survival time was 152 months. Variables significantly associated with short-term survival included being intact and a low total white blood cell (WBC) count. Variables significantly associated with a successful outcome included having surgery later in the study period and negative postoperative nuclear scintigraphy. In the long-term survival analyses, intact dogs and those with higher WBC counts and occlusion pressures and lower bile acid concentrations were more likely to survive.ConclusionsDogs with CEHPSS treated by ARC generally have a good prognosis and prolonged postoperative survival.