McElhinney D B, Parry A J, Reddy V M, Hanley F L, Stanger P
Division of Cardiothoracic Surgery, University of California, San Francisco, USA.
Ann Thorac Surg. 1998 Apr;65(4):1120-6. doi: 10.1016/s0003-4975(98)00112-x.
Stenosis of the branch pulmonary arteries after tetralogy of Fallot repair can result from several mechanisms. In patients with free pulmonary regurgitation and right ventricular dilatation after transannular patch repair, we have observed that the pulmonary outflow tract can dilate and elongate craniad and rotate to the left, resulting in kinking and obstruction of the previously normal left pulmonary artery.
Ten patients referred for reoperation after tetralogy repair with severe pulmonary regurgitation and right ventricular outflow tract dilatation were found to have left pulmonary artery kinking. In 8 of these patients kinking was the sole or partial cause of left pulmonary artery obstruction, whereas there was no documented obstruction in the other 2. All patients underwent right ventricular outflow tract reconstruction and left pulmonary artery repair with removal of the redundancy at the kink point. Patching alone is not an effective method of repair in this condition, because the mechanism of obstruction is not corrected and the patch material can become redundant and lead to recurrent obstruction.
All patients underwent successful pulmonary outflow tract reconstruction. Left pulmonary artery kinking was corrected in all patients, and relief of obstruction was attained in the 8 patients with stenosis. At follow-up ranging from 9 to 58 months, no patient has evidence of recurrent left pulmonary artery stenosis.
Left pulmonary artery kinking should be suspected at long-term follow-up after tetralogy repair in patients with significant pulmonary regurgitation and right-sided dilatation, even if previous evaluations showed no evidence of left pulmonary arterial abnormality. Because unilateral obstruction caused by kinking may lead to asymmetric pulmonary flow, it can exacerbate pulmonary regurgitation and right ventricular dilatation, in effect accelerating the processes that led to kinking in the first place. Kinking can be relieved successfully with the techniques described in this report.
法洛四联症修复术后肺分支动脉狭窄可由多种机制引起。在经环补片修复术后出现肺动脉瓣反流和右心室扩张的患者中，我们观察到肺流出道可向头侧扩张和延长，并向左旋转，导致先前正常的左肺动脉扭结和梗阻。
10例法洛四联症修复术后因严重肺动脉瓣反流和右心室流出道扩张而接受再次手术的患者被发现存在左肺动脉扭结。其中8例患者，扭结是左肺动脉梗阻的唯一或部分原因，而另外2例未记录到梗阻情况。所有患者均接受了右心室流出道重建和左肺动脉修复，去除扭结点处的多余部分。在这种情况下，单纯修补不是一种有效的修复方法，因为梗阻机制未得到纠正，补片材料可能会变得多余并导致反复梗阻。
所有患者均成功进行了肺流出道重建。所有患者的左肺动脉扭结均得到纠正，8例狭窄患者的梗阻得到缓解。在9至58个月的随访中，没有患者有左肺动脉再次狭窄的证据。
在法洛四联症修复术后长期随访中，对于有明显肺动脉瓣反流和右侧扩张的患者，即使先前评估未显示左肺动脉异常，也应怀疑左肺动脉扭结。由于扭结引起的单侧梗阻可能导致肺血流不对称，会加重肺动脉瓣反流和右心室扩张，实际上加速了最初导致扭结的进程。采用本报告中描述的技术可以成功缓解扭结。
