Variations in right ventricular outflow tract morphology following repair of congenital heart disease: implications for percutaneous pulmonary valve implantation.
OBJECTIVE
Our aim was to identify sub-groups of right ventricular outflow tract morphology that would be suitable for percutaneous pulmonary valve implantation and to document their prevalence in our patient population.


METHODS
Eighty-three consecutive patients with right ventricular outflow tract dysfunction (5-41 years, 76% tetralogy of Fallot) referred to our center for cardiovascular magnetic resonance were studied. A morphological classification was created according to visual assessment of three-dimensional reconstructions and detailed measurement. Diagnosis, right ventricular outflow tract type, surgical history and treatment outcomes were documented.


RESULTS
Right ventricular outflow tract morphology was heterogeneous; nevertheless, 5 patterns were visually identified. Type I, a pyramidal morphology, was most prevalent (49%) and related to the presence of a transannular patch. Other types (II-V) were seen more commonly in patients with conduits. Two patients had unclassifiable morphology. Ninety-five percent of patients were assigned to the correct morphological classification by visual assessment alone. Percutaneous pulmonary valve implantation was performed successfully in 10 patients with Type II-V morphology and in 1 patient with unclassifiable morphology. Percutaneous implantation was not performed in patients with Type I morphology. Only right ventricular outflow tract diameters < 22 mm in diameter were suitable for the current device.


CONCLUSIONS
We have created a morphological classification of the RVOT in patients referred for assessment of RVOT dysfunction. Though only 13% of our patients underwent percutaneous implantation, > 50% of outflow tract morphologies may be suitable for this approach, in particular with the development of new devices appropriate for larger outflow.
Schievano
Silvia
S
UCL Institute of Child Health and Great Ormond Street Hospital for Children, London, United Kingdom. s.schievano@ich.ucl.ac.uk
Coats
Louise
L
Migliavacca
Francesco
F
Norman
Wendy
W
Frigiola
Alessandra
A
Deanfield
John
J
Bonhoeffer
Philipp
P
Taylor
Andrew M
AM
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D016017:Odds Ratio; D011664:Pulmonary Valve / Q000601:surgery*; D012189:Retrospective Studies; D013771:Tetralogy of Fallot / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000503:physiopathology / Q000601:surgery*
D003287:Contrast Media; D019786:Gadolinium DTPA