Abnormal veins around the heart with the closure of the coronary sinus ostium

In a cadaveric dissection course at Akita University Graduate School of Medicine in 2014, we observed abnormal veins in a 72-year-old male who died of prostate cancer. The abnormality consisted of the following: closure of the opening of the coronary sinus (closure of the coronary sinus ostium), a persistent left superior vena cava (Lsvc), and a postaortic left brachiocephalic vein (Palbv). The shunt between the coronary sinus and left atrium was not observed. The blood of the coronary sinus flowed into an oblique vein of the left atrium, which was wide and reverse-funnel shaped, penetrated the pericardial sac then continued to the Lsvc. The anastomotic veins between the Lsvc and the (right) superior vena cava were seen to consist of two veins as follows: one was a left brachiocephalic vein, the other a dorsal postaortic left brachiocephalic vein (dorsal Palbv). The dorsal Palbv passed dorsally on the ligamentum arteriosum, and then passed between the ascending aorta and the trachea. The dorsal Palbv was thicker than the left brachiocephalic vein. We discuss the process of formation of these variations.