European Journal of Cardio-Thoracic Surgery, Vol 12, 587-592, Copyright © 1997 by European Association for Cardio-thoracic Surgery
The morphologically tricuspid valve in hypoplastic left heart syndrome
C Stamm, RH Anderson and SY Ho
Paediatrics, Imperial College School of Medicine, National Heart and Lung Institute, London, UK.
OBJECTIVE: Competence of the tricuspid valve is crucial for survival of
children with hypoplastic left heart syndrome. We studied the morphology
and topology of the valvar and subvalvar structures, trying to identify
abnormalities which could impair valvar function. METHODS: A total of 82
specimens with hypoplastic left heart syndrome were examined
pathologically. Measurements of valvar dimensions were taken, significant
dysplasia of the valvar leaflets was noted and the muscular and tendinous
supporting structures determined. The findings were correlated to the
subgroups of hypoplastic left heart syndrome. RESULTS: Of the hearts, 10
(12%) showed a bileaflet right atrioventricular valve, 27 (33%) a
moderately and 2 (2%) a severely dysplastic tricuspid valve. The majority
of the abnormalities was found in hearts with a patent mitral valve. In 79%
of the hearts with mitral atresia, the septal surface was concave instead
of convex to the right ventricular lumen and the direct tendinous
attachments of the septal leaflet replaced by a multitude of freestanding
papillary muscles. The number of direct septal attachments was
significantly higher in hearts with a patent mitral valve. CONCLUSIONS: The
tricuspid valve in hypoplastic left heart syndrome can differ from the
valve seen in normal patients. The subvalvar apparatus is different in
hearts with mitral atresia, whereas dysplasia of the leaflets occurs more
often together with mitral stenosis. These features should be considered in
reconstructive operations as well as during diagnostic procedures.
