Spatial relationship of coronary sinus-great cardiac vein with adjoining anatomic structures: a key element in predicting the success of percutaneous transvenous mitral annuloplasty.

BACKGROUND AND AIM OF THE STUDY: Knowledge of the anatomy of the coronary venous system and its relationship with the mitral valve annulus (MVA) and coronary arteries is a key element to successful percutaneous transvenous mitral annuloplasty (PTMA) device implantation for treating patients with severe mitral regurgitation.

METHODS: The spatial relationship of the coronary sinus-great cardiac vein (CS-GCV) with the MVA, left circumflex coronary artery (LCx) and its branches was examined in 120 formalin-fixed adult human cadaveric hearts.

RESULTS: During the initial part of its journey, the CS-GCV was seen to course along and parallel to the plane of the MVA in 109 cases (90.8%), and to cross the MVA obliquely in 11 cases (9.2%). The LCx crossed deep or superficial to the CS-GCV at a discrete point in 98 cases (81.6%) and in eight cases (6.6%), respectively. In two cases (1.6%), the LCx was overlapped by the CS-GCV for an average length of 3.5 +/- 0.7 cm, and in five cases (4.1%) it lay superficial to the CS-GCV for an average length of 3.1 +/- 1.0 cm. In the remaining seven cases (5.8%), the artery did not accompany the CS-GCV along the MVA. Obtuse marginal arteries and the ramus intermedius were seen coursing deep to the CS-GCV in 40 cases (33.3%) and 33 cases (27.5%), respectively.

CONCLUSION: The study results showed that the CS-GCV crosses the annulus obliquely in 9.2% of cases, and hence might affect the efficiency of PTMA. Similarly, positioning of the annuloplasty device in the CS-GCV in cases where the LCx and its branches lay deep to the vein may result in an impingement of the arteries, leading to ischemia.