Background:

The bidirectional superior cavopulmonary shunt (BSCPS) procedures, bidirectional Glenn shunt (BDG) and hemi-fontan operation, have become a well-established intermediate-stage palliative procedures on the pathway to Fontan operation in patients with a functional single ventricle[-]. Several recent reports investigating pulmonary artery growth after BSCPS procedures have emphasized the reduction in Nakata indices or Z scores [-]. We undertook this study to determine the effect of bidirectional superior cavopulmonary shunt (BSCPS) procedures on the pulmonary artery growth and the factors may be associated with decreased growth of pulmonary artery.

Patients and methods:

Between August 1989 and May 1997, of total 80 patients; 22 underwent BDG shunt, 58 underwent hemi-fontan operation at our institution. The 43 patients were eligible for inclusion into this study. Pre-BSCPS and post-BSCPS angiograms were reviewed retrospectively. Pulmonary artery indices were calculated by the method of Nakata and associates []. Hemodynamic data obtained at pre-BSCPS and post-BSCPS cardiac catheterization were also compared.

Results:

Of the total 43 patients, 27 underwent hemi-fontan, 16 underwent BDG operation. The median duration from BSCPS to post-BSCPS angiography and catheterization was 13 months (range 5 to 54 months). The comparison of the pulmonary artery diameters and indices before and after BSCPS procedure revealed decrease in the indices of the left pulmonary artery (p=0.01), left lower lobe branch (p=0.0007), right lower lobe branch (p=0.02) and total lower lobe branches (p=0.001) significantly. Between BDG and hemi-fontan groups, there were no differences in the pulmonary artery diameters and indices before and after BSCPS procedure.

Conclusion:

The potential reduction in pulmonary blood flow after BSCPS may inhibit the PA growth and influence the success of subsequent Fontan completion.