Giant Right Coronary Artery Aneurysm With a Fistula to the Coronary Sinus: A Case Report

Giant coronary artery aneurysms (CAAs) are rare vascular abnormalities, defined as a dilated segment exceeding four times the normal vessel diameter or >8 mm.Management is challenging due to limited guidelines.This report describes a tortuous right coronary artery (RCA) aneurysm with a fistulous connection to the coronary sinus, initially diagnosed in 2012.Despite radiographic stability for over a decade, the patient underwent complex surgical repair in December 2024, followed by favorable functional recovery at the latest follow-up in October 2025.Giant coronary artery aneurysms with fistulous cardiac connections are exceedingly rare and require individualized management based on aneurysm size, symptoms, anatomical complexity, and risk of complications.Although conservative surveillance may be considered in selected asymptomatic patients, prolonged anatomical stability does not eliminate the potential need for surgical intervention.This case highlights the importance of individualized management, long-term imaging surveillance, and postoperative follow-up.