Conjoined right hepatic artery from branches of the common hepatic and gastroduodenal arteries: a rare anatomic variant

Purpose To describe a previously unreported anatomical variant of the hepatic arterial supply: a conjoined right hepatic artery, formed by branches of the common hepatic artery and gastroduodenal artery. Method A 54-year-old female with oligometastatic colorectal cancer with metastases to the liver presented for planning stage arteriography in preparation for Y90 radioembolization. Results Arteriography of the common hepatic artery demonstrated bifurcation into a right hepatic artery and gastroduodenal artery. The gastroduodenal artery gave rise to a proximal branch, from which the left hepatic artery originated and then continued to anastomose in the hilum of the liver to the right hepatic artery originating from the common hepatic artery. It was initially identified on visceral artery arteriography and then retrospectively recognized on pre-procedural CT scan. Conclusion Anatomical variants of the hepatic arterial supply are important to recognize during planning stage arteriography in preparation for Y90 radioembolization. Knowledge of these variants is also important for pre-operative planning.