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Flow Characteristics of the St. Jude Prosthetic Valve: An In Vitro and In Vivo Study
Author(s) -
Yoganathan Ajit P.,
Chaux Aurelio,
Gray Richard J.,
Robertis Michele,
Matloff Jack M.
Publication year - 1982
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/j.1525-1594.1982.tb01674.x
Subject(s) - body orifice , aortic valve , shear stress , heart valve , in vivo , biomedical engineering , materials science , medicine , cardiology , anatomy , composite material , microbiology and biotechnology , biology
The St. Jude cardiac prosthetic aortic valve was evaluated in vitro and in vivo in an attempt to establish flow characteristics and to correlate them with clinical findings. In vitro, a fluid vehicle (6% Polyol V‐10, 32°C) with viscosity similar to blood (0.035 dyne‐sec/cm 2 ) was used under conditions of steady flow through a flow chamber simulating the aortic root. Gradient, velocity, and shear stress were measured 5.79 mm, 26.79 mm, 44.79 mm, and 77.79 mm downstream from 25‐mm and 27‐mm valves using a laser‐Doppler anemometer. At 417 ml/sec, the valve gradient was 6.2 mmHg with the 25‐mm valve, and 5.2 mmHg with the 27‐mm prosthesis. Velocity was maximum at the orifice center, and wall shear stress was low (maximum 600 dyne/cm 2 ). In vivo, six patients with 25‐mm St. Jude aortic valves were studied within 48 hours after surgery to determine cardiac output, valve flow, and gradient. The gradient was 3.3 ± 1.9 mmHg (M ± SD) at 249 ± 96 ml/sec and the effective valve area was as large as the geometric area (2.58 vs. 3.09 cm 2 ). Thus, flow through the St. Jude valve is unobstructed and central, has low turbulence, and achieves optimal effective valve area for a given available orifice area.