Corno Antonio F, Prosi Martin, Fridez Pierre, Zunino Paolo, Quarteroni Alfio, von Segesser Ludwig K
Alder Hey Royal Children Hospital, Eaton Road, Liverpool, L12 2AP, England, UK.
Eur J Cardiothorac Surg. 2006 Jan;29(1):93-9. doi: 10.1016/j.ejcts.2005.10.029. Epub 2005 Dec 6.
To evaluate the differences between non-circular shape of FloWatch-PAB and conventional pulmonary artery (PA) banding.
Geometrical analysis. Conventional banding and FloWatch-PAB perimeters were plotted against cross-sections. Computational fluid dynamics (CFD) model. CFD compared non-circular FloWatch-PAB cross-sections with conventional banding regarding pressure gradients. Clinical data. Seven children, median age 2 months (7 days to 3 years), median weight 4.2 kg (3.2-9.8 kg), with complex congenital heart defects underwent PA banding with FloWatch-PAB implantation.
Geometrical analysis. Conventional banding: progressive reduction of cross-sections was accompanied by progressive reduction of PA perimeters. FloWatch-PAB: with equal reduction of cross-sections the PA perimeter remained constant. CFD model. Non-circular and circular banding provided same trans-banding pressure gradients for same cross-sections at any given flow. Clinical data. Mean PA internal diameter at banding was 13.3+/-4.5 mm. After a mean interval of 5.9+/-3.7 months, all children underwent intra-cardiac repair and simple FloWatch-PAB removal without PA reconstruction. Mean PA internal diameter with FloWatch-PAB removal increased from 3.0+/-0.8 to 12.4+/-4.5 mm (normal mean internal diameter for the age=9.9+/-1.6). No residual pressure gradient was recorded in correspondence of the site of the previous FloWatch-PAB implantation in 6/7 patients, 10 mmHg peak and 5 mmHg mean gradient in 1/7.
The non-circular shape of FloWatch-PAB can replace conventional circular banding with the following advantages: (a) the pressure gradient will remain essentially the same as for conventional circular banding for any given cross-section, but with significantly smaller reduction of PA perimeter; and (b) PA reconstruction at the time of de-banding for intra-cardiac repair can be avoided.
评估FloWatch - PAB的非圆形形状与传统肺动脉（PA）环扎术之间的差异。
几何分析。将传统环扎术和FloWatch - PAB的周长与横截面积进行绘图。计算流体动力学（CFD）模型。CFD比较了非圆形FloWatch - PAB横截面积与传统环扎术在压力梯度方面的情况。临床数据。7名年龄中位数为2个月（7天至3岁）、体重中位数为4.2 kg（3.2 - 9.8 kg）的患有复杂先天性心脏病的儿童接受了PA环扎术并植入了FloWatch - PAB。
几何分析。传统环扎术：横截面积逐渐减小伴随着PA周长逐渐减小。FloWatch - PAB：在横截面积同等减小的情况下，PA周长保持不变。CFD模型。在任何给定流量下，对于相同的横截面积，非圆形和圆形环扎术提供相同的跨环扎压力梯度。临床数据。环扎时PA的平均内径为13.3±4.5 mm。平均间隔5.9±3.7个月后，所有儿童均接受了心内修复并简单移除了FloWatch - PAB，未进行PA重建。移除FloWatch - PAB时PA的平均内径从3.0±0.8增加到12.4±4.5 mm（该年龄的正常平均内径为9.9±1.6）。7例患者中有6例在先前FloWatch - PAB植入部位未记录到残余压力梯度，1例记录到峰值10 mmHg和平均梯度5 mmHg。
FloWatch - PAB的非圆形形状可替代传统的圆形环扎术，具有以下优点：（a）对于任何给定的横截面积，压力梯度将与传统圆形环扎术基本相同，但PA周长的减小显著更小；（b）在心内修复解除环扎时可避免PA重建。
