Morphological and Morphometric Study of the Coronary Sinus and its Tributaries in Adult Cadaveric Hearts: A Descriptive Anatomical Study

Background: The coronary sinus (CS) is the principal venous conduit of the heart and provides an important route for cardiac electrophysiological and interventional procedures. Variations in its dimensions, ostium, valves, tributaries and relationship with surrounding structures may influence coronary sinus cannulation and device placement. This study evaluated the morphology and morphometry of the CS and its associated structures in adult cadaveric hearts. Methods: This descriptive anatomical study included 58 formalin-fixed adult cadaveric hearts and was conducted from October 2022 to February 2025 at Sukh Sagar Medical College & Hospital, Chargawan, Jabalpur, Madhya Pradesh, India. The dimensions of the coronary sinus, coronary sinus ostium, left posterior atrioventricular sulcus and heart were measured. The morphology of the coronary sinus and Thebesian valve, myocardial covering, tributary drainage patterns, opening angles and the relationship of the coronary sinus with the left circumflex artery were recorded. Correlation analyses were performed, and a p value ≤0.05 was considered statistically significant. Results: The mean CS length was 35.07±8.80 mm and mean width was 8.28±1.37 mm. The CS occupied 69.22% of the left posterior atrioventricular sulcus. CS length showed a strong positive correlation with sulcus length (r=0.876, p<0.0001) and moderate positive correlations with heart length (r=0.535, p<0.001) and heart width (r=0.481, p<0.001). All specimens had a tubular CS, and the CS was positioned above the left circumflex artery in all 58 hearts. The CS ostium was oval in all specimens, with a mean transverse width of 8.32±1.72 mm and vertical length of 8.43±1.67 mm. The Thebesian valve was semilunar in 82.75% of specimens. The great cardiac vein and oblique vein of the left atrium drained into the CS in all specimens. Conclusion: The coronary sinus showed variation in its dimensions, myocardial covering, tributary drainage and Thebesian valve morphology despite uniform tubular morphology and an oval ostium. CS length showed positive correlations with the length of the left posterior atrioventricular sulcus and with heart length and width. These anatomical findings may be relevant to procedures requiring coronary venous access.