In a 58-year-old man with HCC undergoing TACE, a segment III tumor was supplied by an accessory left hepatic artery arising from the left gastric artery (LGA). The dominant technical challenge shifted from acute angulation at the LGA origin to inadequate back support in distal branches. To overcome repeated dislodgement, the catheter was exchanged for a 5-Fr catheter with a hand-cut side hole, positioned at the LGA orifice while the tip was anchored in the celiac trunk. This technique allowed a microcatheter to traverse in a single well-supported pass, enabling successful superselective TACE without immediate complications. This case emphasizes the importance of distinguishing ostial angulation from back-support failure and highlights the utility of proximal side-hole anchoring in complex multivessel selection.

Variant right inferior adrenal arterial supply to caudate lobe HCC is rare and may be overlooked. We report a 53-year-old man with recurrent caudate lobe HCC after 12 TACE sessions. During the 13th TACE, cone-beam CT of the common hepatic artery did not reveal tumor vascularity. At the 14th TACE, performed 3 days later, the right inferior phrenic artery, the most common extrahepatic collateral feeder to caudate lobe HCC, showed no tumor supply. Angiography and cone-beam CT from a small aortic common trunk giving rise to a variant right inferior adrenal artery and the right renal capsular artery revealed predominant supply from the variant right inferior adrenal artery. Embolization through these branches achieved compact iodized oil uptake without immediate complications.

Extrahepatic collateral supply from the Sappey superior artery of the right internal thoracic artery (RITA) is an uncommon but important source of perfusion to HCC located in segment IV. Preprocedural CT demonstrated a large segment IV HCC supplied by the Sappey superior artery. Initial transfemoral angiography confirmed tumor vascularization but failed to achieve superselective catheterization because of marked tortuosity of the aortic arch. The procedure was converted to a right transradial approach, which provided stable access to the RITA and enabled successful superselection of the Sappey superior artery. Y-90 radioembolization via the Sappey superior artery and hepatic artery was completed without complications.