Intrahepatic and extrahepatic portal venous anomalies in dogs: 52 cases (1982-1992).

Medical records of 52 dogs born with portal venous anomalies (PVA) were reviewed and separated into 2 groups, based on anatomic location of the shunt (intrahepatic vs extrahepatic). Statistical analysis was used to compare the groups with respect to presurgical clinicopathologic data, as well as to compare presurgical clinicopathologic data with postoperative mortality. Three presurgical predictors of location were identified. Mean body weight at admission was statistically different (P = 0.0001) between dogs with an intrahepatic PVA (mean, 15 kg) and those with an extrahepatic PVA (mean, 4.8 kg). Blood glucose concentration was significantly (P = 0.028) higher in dogs with an intrahepatic PVA (mean, 99.8 mg/dl) than in dogs with an extrahepatic PVA (mean, 85.1 mg/dl). The third significant (P = 0.036) predictor of location was degree of elevation of serum alkaline phosphatase concentration. The intrahepatic location resulted in a concentration 3.2 times that of the reference value, whereas an extrahepatic location resulted in a 1.7 times increase. Two predictors of early postoperative mortality were identified. In comparing the 2 groups, significant differences in PCV before surgery (P = 0.04) and in rectal temperature after surgery (P = 0.002) were found. Dogs that survived had a mean presurgical PCV of 36% and a mean postoperative rectal temperature of 35.7 C, whereas nonsurvivors had a mean presurgical PCV of 40.6% and a mean temperature of 34.3 C. There was no significant difference between nonsurvivors and survivors with respect to postligation portal pressure or change in portal pressure after ligation. Overall mortality was 15%.