AbstractOBJECTIVESSurgical supra-annular aortic valvar tissue prostheses are labelled in an inconsistent and confusing manner. If the replaced valve is too small for a given patient, the risk of patient-prosthesis mismatch is increased, which is associated with the risk of morbidity and mortality. The labelled diameter (LD) of these valves should coincide with the inflow orifice diameter (IOD). Therefore, our goal was to measure all relevant IODs.METHODSValvar design was assessed in terms of the intended position of the valve in relation to the patient’s annulus. The IODs of all available supra-annular aortic valvar prostheses were measured using a conical gauge. The IODs were compared to the LDs. We searched for instructions for use, websites, packing boxes and regulatory institutions involved in the process.RESULTSEight valve models from 4 manufacturers were included. None of these valves were clearly labelled as supra-annular on the packing box, although for 3, the supra-annular label could be found in the written specifications. All valves had an IOD smaller than their LD, with a median difference of 15% (range: 4%–25%). The departure from LD differed per valve model and valve size.CONCLUSIONSValve packages should be labelled accurately and clearly so that surgeons can make a well-informed choice. Currently essential information is missing because the intended position in relation to the annulus is not consistently marked on the packing boxes, and valve sizes are labelled incorrectly. We propose a change for the better: relabel all valves according to their true IOD in a structured manner.