In vitro comparison of different mechanical prostheses suitable for replacement of the systemic atrioventricular valve in children

Objective The aim of the present study was to compare the hydrodynamics of 4 different mechanical prostheses fitting the atrioventricular annulus in children. Methods We tested different inverted aortic prostheses with a prosthesis–annulus relationship in the mitral chamber of the Sheffield pulse duplicator (Department of Medical Physics and Clinical Engineering, Royal Hallamshire Hospital, Sheffield, UK), analyzed by comparing the prosthetic housing diameter and the predicted annulus diameter based on body surface area (0.8 and 1 m2 corresponding to an annulus diameter of 18.8–20.2 mm). The On-X 19 (On-X Life Technologies, Inc, Austin, Tex), SJM Regent 19 (St Jude Medical Inc, St Paul, Minn), Sorin Overline 18 (Sorin Biomedica, Saluggia, Italy), and Medtronic Advantage Supra 19 (Medtronic Inc, Minneapolis, Minn) valves with a housing diameter of 19 to 20 mm were hydrodynamically compared. The tests were carried out at increasing pulse rate of 72, 80, 100, and 120 beats/min for a stroke volume of 20 and 30 mL. Therefore, cardiac output ranged from 1.44 to 3.6 L/min. Results Regardless of the pulse rate and stroke volume, the Medtronic Advantage Supra valve showed the highest mean diastolic pressure difference at each cardiac output ( P