1. Variation of Coronary Artery Anatomy in Transposition of the Great Arteries Piya Samankatiwat Ramathibodi Hospital Mahidol University

2. Introduction Anatomical variation of coronary artery in TGA is complicated. Literally, classification of coronary artery in TGA is inhomogeneous. The usual type is not that usual, only just slightly more than 60% Correct preoperative recognition is sometimes difficult. Influence on outcome of surgery is still controversial.

3. Definition of coronary artery

5. Coronary artery morphology

6. Patterns in TGA (Leiden Convention) The “normal” coronary disposition in TGA is: 1LCx 2R (the disposition appears inverted as compared with the disposition in the normal heart). The most frequent anomalies encountered are: 1L 2RCx, 1Cx 2RL, 1R 2LCx, 2LCxR, 2RLCx, 2CxRL,1RLCx. These may pose special surgical problems or even contraindicate the switch at arterial level.  in particular single coronary artery and intramural type. Muresian H. Coronary arterial anomalies and variations Mædica A Journal of Clinical Medicine, Volume1 No.1 2006

7. Yacoub MH, Radley-Smith R. Thorax, 1978, 33, 418-424

8. Wernovsky G and Sanders SP Coron Artery Dis. 1993;4:148–157. Pasquali et al. Circulation. November 12, 2002

9. Patients and method An observational study 20 consecutive patients underwent arterial switch operation. Anatomical patterns of coronary arteries were recorded. Special concern on difficult types.

10. Results Median age 12 days (3-480 days) Male:Female 3:1 14 newborns, 5 infants and 1 child One Dextrocardia

11. Dextrocardia case

12. Results 1LCx 2R60% (n=12) 1 usual type with separated orifice of right ventricular branch from sinus 1. 1L 2RCx25% (n=5) 2RLCX15% (n=3) 2 cases posterior course of LCA 1 case anterior course

13. Results 1LCx 2R 60 % N=12 0 % 1L 2RCx 25 % N=5 2RLCx 15 % N=3 0 %

14. Conclusion Coronary artery pattern in TGA was inconsistent. Usual pattern in only 60 % Difficult to determine if higher risk of arterial switch operation was associated with a particular type of coronary artery anatomy. Our series: all single coronary artery cases survive. The value of preoperative recognition of the pattern of coronary artery and outcome of surgery for TGA is still skeptical. Further observation

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