Department of Cardiothoracic Surgery, University of Tokyo Hospital, Bunkyou-ku, Tokyo, Japan.
J Thorac Cardiovasc Surg. 2010 Nov;140(5):1084-91. doi: 10.1016/j.jtcvs.2010.07.084. Epub 2010 Sep 17.
In patients with high-risk hypoplastic left heart syndrome (HLHS), the Norwood operation (NW) in the neonatal period still results in high mortality compared with other cardiac surgery. Bilateral pulmonary artery banding (bPAB), a very effective initial procedure for HLHS, for which the specific evaluation is as yet unsatisfactory, was performed, and we report our findings in the present study.
We have performed bPAB since 2006. A total of 17 patients with HLHS or a variant underwent bPAB before the NW. Echocardiography was performed between bPAB and the NW, and the flow acceleration just after bPAB and before NW was evaluated. Before the NW, a catheter examination was also performed.
bPAB was performed at 6.6 ± 0.6 days of age, and the NW at 130 ± 88 days. The patients' mean body weight (BW) was 2.5 ± 0.4 kg at bPAB and 4.0 ± 1.1 kg at the NW. The length of the tape for bPAB was 9.9 ± 0.6 mm in the right pulmonary artery (RPA) and 9.4 ± 0.6 mm in the left (LPA) because the RPA was usually wider than the LPA. The tape width was 2 mm in all cases. The catheter examination was performed at 95 ± 85 days after bPAB. The arterial oxygen saturation (SaO₂) was 71% ± 8.6%. Multivariate regression analysis revealed that SaO₂ was estimated well using 4 factors: the banding size of the RPA, BW at bPAB, BW at NW, and BW in the period between bPAB and catheter examination (R² = 0.79). Echocardiography just after bPAB showed that the blood flow at the bPAB had accelerated to 3.0 ± 0.8 m/s in the RPA and 3.3 ± 0.8 m/s in the LPA (P = .004). The estimated pressure gradient was 39.2 ± 17.6 mm Hg in the RPA and 46.1 ± 23.0 mm Hg in the LPA (P = .006). The blood flow at bPAB was accelerated to 3.7 ± 0.7 m/s in the RPA and 4.0 ± 0.6 m/s in the LPA before NW (P = .013). The estimated pressure gradient was 62.6 ± 27.6 mm Hg in the RPA and 56.1 ± 19.6 mm Hg in the LPA before NW (P = .014). The catheter examination revealed mean wedge pressures of 18.0 ± 7.2 mm Hg for the RPA and 16.2 ± 4.3 mm Hg for the LPA. The operative mortality rate was 0%. One patient required a repeat operation to adjust the bPAB, and prolonged pleural effusion was observed in 1 case.
The postoperative SaO₂ after bPAB correlated closely with the banding size and BW at bPAB, NW and during the period after bPAB. Because the mean PA pressure before NW was low enough for single ventricular circulation, the bPAB in this study was an effective option for high-risk patients undergoing HLHS or a variant. We believe the bPAB sizes used were suitable and were determined as follows: BW plus 7 mm for the LPA and BW plus 7.5 mm for the RPA.
对于高危左心发育不全综合征（HLHS）患者，新生儿期的 Norwood 手术（NW）仍然导致死亡率高于其他心脏手术。双侧肺动脉带缩术（bPAB）是 HLHS 的一种非常有效的初始手术，但目前对其特定评估并不满意，我们报告了本研究中的发现。
我们自 2006 年以来一直进行 bPAB。共有 17 例 HLHS 或变异患者在 NW 前接受 bPAB。在 bPAB 和 NW 之间进行超声心动图检查，并评估 bPAB 后和 NW 前的血流加速情况。在 NW 前还进行了导管检查。
bPAB 于 6.6±0.6 天龄进行，NW 于 130±88 天龄进行。患者的平均体重（BW）在 bPAB 时为 2.5±0.4kg，在 NW 时为 4.0±1.1kg。bPAB 时右肺动脉（RPA）的带缩长度为 9.9±0.6mm，左肺动脉（LPA）为 9.4±0.6mm，因为 RPA 通常比 LPA 宽。所有病例的带缩宽度均为 2mm。bPAB 后 95±85 天行导管检查。动脉血氧饱和度（SaO₂）为 71%±8.6%。多元回归分析显示，SaO₂可通过 4 个因素良好估计：RPA 的带缩大小、bPAB 时的 BW、NW 时的 BW 和 bPAB 与导管检查之间的 BW（R²=0.79）。bPAB 后即刻的超声心动图显示，bPAB 的血流速度在 RPA 加速至 3.0±0.8m/s，在 LPA 加速至 3.3±0.8m/s（P=0.004）。RPA 的估计压力梯度为 39.2±17.6mmHg，LPA 为 46.1±23.0mmHg（P=0.006）。NW 前 RPA 的血流速度加速至 3.7±0.7m/s，LPA 加速至 4.0±0.6m/s（P=0.013）。RPA 的估计压力梯度为 62.6±27.6mmHg，LPA 为 56.1±19.6mmHg（P=0.014）。导管检查显示 RPA 的平均楔压为 18.0±7.2mmHg，LPA 为 16.2±4.3mmHg。手术死亡率为 0%。1 例患者需要重复手术调整 bPAB，1 例患者出现长时间胸腔积液。
bPAB 后术后 SaO₂与 bPAB 时的带缩大小和 BW、NW 以及 bPAB 后期间的 BW 密切相关。由于 NW 前平均肺动脉压力足以支持单心室循环，因此本研究中的 bPAB 是高危 HLHS 或变异患者的有效选择。我们认为使用的 bPAB 尺寸合适，确定方法如下：LPA 加 BW 7mm，RPA 加 BW 7.5mm。
