The cardiac veins in congenitally corrected transposition of the great arteries: Delivery options for cardiac devices

Background: Device implantation is sometimes required in congenitally corrected transposition of the great arteries (ccTGA) because of morphologic right ventricular (RV) dysfunction and complete heart block. The anatomical course of the veins remains unknown, despite well-described coronary arterial anatomy. Knowledge of the venous anatomy may facilitate planning of percutaneous cardiac procedures in these patients. Objective: This study sought to characterize the venous anatomy in ccTGA. Methods: Pathologic cardiac specimens from patients with ccTGA were identified from the Mayo Clinic pathology database. Coronary sinus (CS) anatomy and distances from the CS ostium to the major cardiac veins were evaluated. Thebesian veins with ostial openings >1 mm, epicardial veins, and venous collaterals were also quantified. Results: There were 56 hearts with a diagnosis of ccTGA identified. The CS was unidentifiable in 5 hearts due to slicing, and assessment of the Thebesian veins was not possible in 16. Seven hearts had an abnormal CS, 2 of which had atretic ostia and the other 5 of which either had an abnormal ostial location or multiple ostia. There were 28 hearts with at least 1 Thebesian vein with an ostial opening >1 mm. All 12 hearts with unidentifiable Thebesian veins had venous collaterals from the right ventricle (RV) to the major cardiac veins. Epicardial veins extended to the proximal, middle, and distal thirds of the RV in 71%, 23%, and 6%, respectively. Conclusion: In ccTGA, the ventricular venous anatomy is abnormal and follows the morphologic RV. However, large interventricular and Thebesian veins may offer options for percutaneous lead or catheter placement when approaching the systemic RV.