The knowledge of the different anatomical types of the Thebesius valve should clarify some problems observed in coronary sinus catheterization. Ninety-four human normal hearts were analysed by an incision in he right atrium from the inferior vena cavae through the terminal groove, allowing inspection of the coronary sinus. Based on the anatomical features of the Thebesius valve, we identify 5 different groups, i.e.: 1) absent valve (16%) when no valve exists; 2) residual valve (33%) when there was only a small membrane occluding less than 15% of the sinus diameter; 3) partial valve (43%) when a membrane occludes more than 15% of the sinus diameter; 4) trabeculated valve (7%) when there was no membrane but trabeculation over the sinus; 5) double valve (1%) when there were 2 membranes over the sinus in different positions. In all cases we tried to perform catheterization of the coronary sinus with 2 different types of catheters commonly used in hemodynamic studies. We observed more difficulty to catheterize the coronary sinus with partial or trabeculated valves. There was no statistical relationship between the different valves and age, sex or race.
Thebesius valve