Evaluation of prosthetic valve obstruction on electrocardiographically gated multidetector-row computed tomography--identification of subprosthetic pannus in the aortic position.
BACKGROUND
This study was performed to evaluate the diagnostic role of electrocardiographically gated multidetector-row computed tomography (MDCT) for prosthetic valve obstruction (PVO) in the aortic position.


RESULTS
Between 2002 and 2006, 9 patients were diagnosed with PVO of an aortic bileaflet mechanical valve based on echocardiographic and cineradiographic criteria. These 9 patients were examined using MDCT before replacement of the mechanical valve, and intraoperative findings were compared to morphologic periprosthetic abnormalities observed on MDCT. CT attenuation (Hounsfield units; HU) of the periprosthetic abnormalities was measured to investigate the underlying cause of the PVO. MDCT showed subprosthetic masses extending beyond the prosthetic ring into the orifice of the valve. At reoperation, presence of subprosthetic pannus was confirmed in all of the 9 patients, but no periprosthetic thrombus was found. The mean CT attenuation of the subprosthetic pannus was 170 HU, and it was significantly greater than that obtained from the interventricular septum (108 HU; P<0.0001).


CONCLUSIONS
MDCT can be used to clearly visualize subprosthetic pannus causing PVO and the mean CT attenuation of subprosthetic pannus is significantly higher than that of the interventricular septum on MDCT.
Department of Surgery, Kurume University School of Medicine, Kurume 830-0011, Japan. tomohiro_u17@med.kurume-u.ac.jp
Tomohiro
T
Ueda
Hideki
H
Teshima
Shuji
S
Fukunaga
Shigeaki
S
Aoyagi
Hiroyuki
H
Tanaka
D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000601:surgery; D000082882:Bicuspid Aortic Valve Disease; D002933:Cineradiography / Q000379:methods; D017548:Echocardiography, Transesophageal; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000601:surgery*; D006346:Heart Septum / Q000000981:diagnostic imaging; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging* / Q000601:surgery*; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011475:Prosthesis Failure / Q000209:etiology*