[Predictors of hemodynamically successful left pulmonary artery stent implantation in patients after repair of tetralogy of Fallot].
OBJECTIVE
Left pulmonary artery stenosis is a well-known postoperative complication in patients with tetralogy of Fallot. Recently, balloon expandable intravascular stents have been widely used to relieve those lesions. However, the increase in left pulmonary blood flow is not adequate in some patients, although the vessels are suitably dilated. This study evaluated the predictors of hemodynamical improvement.


METHODS
The study population consisted of nine patients with morphologically successful stent implantation for left pulmonary artery stenosis after repair of tetralogy of Fallot. Patients were divided into two groups. Four patients had hemodynamical improvement by stent implantation, with relative perfusion of the left lung of over 30% of total pulmonary perfusion. The other five patients had relative perfusion of the left lung of under 30% of total pulmonary perfusion after stent implantation. The timing of stent implantation and the morphological features of pulmonary artery were compared between the two groups.


RESULTS
In hemodynamically improved patients, the stent implantation was performed earlier(6.1 +/- 3.5 vs 16.1 +/- 6.5 years old, p = 0.029), and the interval between surgical repair and stenting was shorter (3.7 +/- 2.7 vs 11.3 +/- 4.7 years, p = 0.025). There was no difference in the left pulmonary artery diameter after stenting, but the right pulmonary artery diameter was significantly smaller in hemodynamically improved patients (99.0 +/- 23.7 vs 135.0 +/- 15.1% normal, p = 0.027).


CONCLUSIONS
Effective stent implantation for left pulmonary artery stenosis in patients with tetralogy of Fallot after repair must be performed before compensatory right pulmonary artery growth occurs.
Murakami
Tomoaki
T
Department of Pediatrics, Hokkaido University, Graduate School of Medicine, N-15, W-7, Kita-ku, Sapporo 060-8638. murat@med.hokudai.ac.jp
Ueno
Michihiko
M
D001157:Arterial Occlusive Diseases / Q000503:physiopathology* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D003251:Constriction, Pathologic; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D011183:Postoperative Complications / Q000503:physiopathology; D011651:Pulmonary Artery / Q000473:pathology / Q000601:surgery; D011652:Pulmonary Circulation; D015607:Stents; D013771:Tetralogy of Fallot / Q000503:physiopathology* / Q000601:surgery