Material and methods
Since 1989 thirty-nine consecutive patients (21 boys, 18 girls) were
included in this protocol. A 22Q11 deletion was diagnosed in 10
patients. The median age at the time of the first unifocalization was 13
months (range 2 weeks to 189 months). Diagnostic catheterization was
performed to assess the pulmonary vascularity and perfusion. In 13
patients with a hypoplastic central confluent pulmonary artery a central
aorto-pulmonary shunt was performed, intended to allow the confluent
pulmonary artery to grow to improve the starting point for
unifocalization.
Unifocalization was performed through a lateral thoracotomy with
identification of all collateral arteries at that side. When adequate
intrapulmonary connection was confirmed on preoperative angiography or
intra-operatively, the dual supply SPCA could be closed. When such
connection was not established, the collateral artery was anastomosed to
the native pulmonary artery as close as possible to the hilar pulmonary
vasculature. In case of an absent confluent pulmonary artery and in
cases where further augmentation was indicated a modified
Blalock-Taussig shunt was constructed to the ipsilateral subclavian
artery. In 27 patients an additional unifocalization procedure on the
contra-lateral side was performed to augment the blood supply to that
lung. Before and after each procedure an angiogram was made.
To evaluate the growth of the pulmonary arterial system we
retrospectively measured the pre- and post-unifocalization
Nakata-index.[9]
The change in lung perfusion on angiogram pre- and post-unifocalization
was studied retrospectively to evaluate the result of the procedure. We
studied the total lung perfusion including perfusion by the SPCA’s
versus the lung perfusion by flow through the confluent pulmonary artery
alone.
Based on the angiographic findings and data from catheterization
measurements patients were selected for total correction. Pulmonary
hypertension or unfavorable anatomic result of unifocalization at
angiogram were contraindications for total correction. The total
correction was performed through a median sternotomy with the use of
extracorporeal circulation and moderate hypothermia. The modified
Blalock-Taussig and central shunts were divided. The VSD was closed with
a Gore-Tex® patch and a cryopreserved pulmonary homograft was interposed
between the RVOT and the proximal pulmonary arterial system.
Postoperative recovery and hospital or 30-day mortality is reported.
Long-term follow up was derived from the records. In 24 survivors, with
a complete repair, echocardiographic data were available except in one
patient who was lost to follow up. From 17 patients after successful
correction MR imaging was available for analysis of the right
ventricular function.
This study was approved by the Ethical Committee with no need for
informed consent.
Statistical analysis was performed using Statistical Package for the
Social Sciences (SPSS) software, version 24.0 (SPSS Inc., Chicago, IL).
Frequencies were given as absolute numbers and percentages. The data
were expressed as median with range. The paired t-test was performed for
statistical analysis. We applied the χ 2 test to
compare frequencies in the two groups. The Kaplan-Meier method was
applied to estimate freedom from reintervention and for survival. A P
value less than 0.05 was considered to indicate statistical
significance.