All surgical supra-annular aortic valvar tissue prostheses are labelled too large.

Abstract

Surgical supra-annular aortic valvar tissue prostheses are labelled in an inconsistent and confusing manner. This increases the risk for patient prosthesis mismatch (PPM), when the replaced valve is too small for a given patient, which is associated with the risk of morbidity and mortality. Labelled diameter (LD) of these valves should coincide with inflow orifice diameter (IOD). Therefore, we set out to measure all relevant IOD's. Valvar design was assessed as to their intended position in relation to the patient's annulus. IOD's of all available supra-annular aortic valvar prostheses were measured using a conical gauge. IOD's were compared to LD's. We searched for instructions for use, websites, packing boxes and regulatory institutions involved in the process. Eight valve models of four manufacturers were included. None of these valves were clearly labelled as supra-annular on the packing box, although in three this could be found in the 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. Valve packages should be labelled accurately and clearly for surgeons to make a well-informed choice. Currently essential information is missing, since 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, and relabelling of all valves according to their true IOD in a structured manner.