Anatomical relationship between mitral valve annulus and circumflex artery and its surgical implications.

BACKGROUND: Performing surgical procedures around the mitral valve (MV) annulus can cause iatrogenic lesions on the circumflex artery (Cx). The risk of this iatrogenesis comes from the proximity between this vessel and the MV annulus. OBJECTIVE: To evaluate the relation between the MV annulus and the Cx at different spots of its path and highlight the risks of its damage. METHODS: Fifty cadaveric adult human hearts were studied. Each heart was categorized depending on coronary dominance, and Cx was classified in type 1 (Cx giving off only the left posterior ventricular artery) and type 2 (Cx reaching the crux cordis and giving off the posterior interventricular branch). Three reference spots were chosen: A- when Cx begins to run across the coronary sulcus; B- immediately before the left posterior ventricular artery emerges and C- in the midpoint of the two previous points; to measure the diameter of the Cx and the MV annulus. Values of P<0.05 were considered significant. RESULTS: A total of 43 (86%) hearts were classified in type 1. These hearts showed that the diameter of the Cx in spot A is bigger than in the B and C spots (P=0.001). The 7 hearts (14%) classified in type 2 did not exhibit a difference in the diameter of the Cx in the A, B and C spots (NS). Also, the thickness of the fibrous annulus, in type 1 and type 2 hearts were not different between the three spots (NS). CONCLUSION: The present study showed that the diameter of the Cx varies depending on the heart type. This knowledge might improve the success rate of cardiac surgeries and decrease the rates of iatrogenic Cx lesions.

Anatomical study of length and branching pattern of main trunk of the left coronary artery.

The left coronary artery is responsible for the irrigation of important heart structures. The objective of this study was to analyze the morphological characteristics of the main trunk of left coronary artery in the Brazilian population and its clinical implications. The study was carried out by using 63 adult human hearts of the human anatomy laboratory of the Federal university of Ceará, Brazil. The hearts were dissected for exposure and analysis of the left coronary artery and its branches. The data collected were statistically analyzed. The main trunk arose from the left aortic sinus under the left atrial auricle in all the 63 hearts. The mean length of the main trunk was 8.53±4.03mm. According to the criteria for the classification of the main trunk length, about 78% were medium-sized. The majority of the hearts (52.38%) showed trifurcation of the main trunk. Anova test followed by the Tukey's post hoc test showed that the main trunk length of hearts with trifurcation was significantly longer when compared with hearts with bifurcation (9.77±4.31mm vs. 6.44±3.01mm; P=0.0029). Similar findings were observed in the main trunk length of the hearts with tetrafurcation in comparison with hearts with bifurcation (10.78±1.4mm vs. 6.44±3.01mm; P=0.0387). This study showed that there is a correlation between the branching pattern and the length of the main trunk. Additionally, we showed that the most common branching pattern of the main trunk is the trifurcation, differing from other Brazilian studies and providing additional information to professionals of cardiology, cardiovascular surgery, and radiology.