Figure 2.

 Distribution of procedures carried out over the three eras. Over the study eras there was a major increase in the proportion of patients undergoing the more complex procedures such as pulmonary valve replacement (PVR) and conduit replacements (for example, Rastelli). χ² p<0.0001 across eras. The differences are accounted for by the decrease in secundum atrial septal defects (SASD) and Fontan operations and the increases in PVR and conduit replacements in era 3 compared with both era 1 and era 2. There were less noticeable differences between era 1 and era 2. (appendix 2). Aortic, procedures isolated to the aorta itself, such as coarctation; Fontan, any type of Fontan-type operation; LVOT, left ventricular outflow tract procedures such as procedures for aortic stenosis; PA, pulmonary artery.