Computed tomographic lymphangiography following percutaneous intrahepatic injection of iopamidol in cats

Abstract

To determine if computed tomographic lymphangiography (CTL) after ultrasound-guided percutaneous injection of intrahepatic iopamidol (Isovue 370) in healthy cats would safely and effectively lead to opacification of the hepatic lymphatics, cisterna chyli, and thoracic ducts (TDs). A prospective pilot study design with randomization of the sides of the liver injected. 6 purpose-bred cats. Cats were anesthetized and based on random assignment, and the left or right liver was injected with iodinated contrast material. CTL images were taken at 5, 10, and 15 minutes postinjection to determine the quality of opacification of the cisterna chyli and TDs. Eleven hepatic injections from 6 cats were available for review. One CT file was corrupted and unusable. Seven out of 11 hepatic contrast injections yielded a diagnostic study. Five out of 11 were graded as excellent, 0/11 were graded as good, and 2/11 were graded as fair. Opacification of the cisterna chyli and TDs was absent in 4/11 studies. Three out of 6 cats had mild to moderate increases in hepatocellular enzymes when assayed 3 months postprocedure. The hepatic lymphatics, cisterna chyli, and TDs were opacified in all studies deemed diagnostic. Intrahepatic contrast injection offers a novel portal for thoracic duct lymphangiography that documents the hepatic contribution to the mesenteric lymphatics, cisterna chyli, and thoracic duct. The procedure may be helpful in the preoperative diagnostic evaluation of cats with chylothorax.