Precise evaluation of bilateral pulmonary artery banding for initial palliation in high-risk hypoplastic left heart syndrome

Abstract

Objectives: 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. Methods: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.Results: bPAB was performed at 6.6 AE 0.6 days of age, and the NW at 130 AE 88 days. The patients' mean body weight (BW) was 2.5 AE 0.4 kg at bPAB and 4.0 AE 1.1 kg at the NW. The length of the tape for bPAB was 9.9 AE 0.6 mm in the right pulmonary artery (RPA) and 9.4 AE 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 AE 85 days after bPAB. The arterial oxygen saturation (SaO 2 ) was 71% AE 8.6%. Multivariate regression analysis revealed that SaO 2 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 (R 2 ¼ 0.79). Echocardiography just after bPAB showed that the blood flow at the bPAB had accelerated to 3.0 AE 0.8 m/s in the RPA and 3.3 AE 0.8 m/s in the LPA (P ¼ .004). The estimated pressure gradient was 39.2 AE 17.6 mm Hg in the RPA and 46.1 AE 23.0 mm Hg in the LPA (P ¼ .006). The blood flow at bPAB was accelerated to 3.7 AE 0.7 m/s in the RPA and 4.0 AE 0.6 m/s in the LPA before NW (P ¼ .013). The estimated pressure gradient was 62.6 AE 27.6 mm Hg in the RPA and 56.1 AE 19.6 mm Hg in the LPA before NW (P ¼ .014). The catheter examination revealed mean wedge pressures of 18.0 AE 7.2 mm Hg for the RPA and 16.2 AE 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. Conclusions:The postoperative SaO 2 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.

Bilateral pulmonary artery banding for initial palliation in high-risk hypoplastic left heart syndrome

“…10 Kitahori and his colleagues advocated a novel formula: for the left PA, the best band size would be bodyweight plus 7 mm; for the right PA, it would be bodyweight plus 7.5 mm. 8 Even though we did not follow the established procedures, we were still able to achieve satisfactory results by meticulous intraoperative arterial oxygen saturation and hemodynamic monitoring.…”

“…7 Since then, this initial palliation has gradually attracted attention because it is less invasive. 4,5,8,9 Appropriate regulation of PA flow and ductus maintenance are the two most critical issues in minimally-invasive procedures. Apparently, the original design of PA banding was not suitable in complicated cases.…”

“…4,5,8,9 Stenting the ductus arteriosus has the advantage of adequate blood flow regulation and it avoids the disadvantages associated with the long-term use of prostaglandin E1, such as thinning of the ductal wall, abrupt closure or even aneurismal rupture. Rupture, migration and in-stent stenosis are not rare complications related to ductal stenting.…”

Computational modelling of the hybrid procedure in hypoplastic left heart syndrome: A comparison of zero-dimensional and three-dimensional approach

“…During Hybrid procedure the PAB dimension is empirically based on patient's body weight and calibrated during surgery to achieve desired systemic oxygen saturations and pressure. Because the method is imprecise and the clinical parameters used to inform the PAB size reflect poorly the ventricular workload and circulation, the condition still carriers a significant risk [1,2]. Computational models have been used to inform congenital circulations and surgical intervention including Norwood and Hybrid procedure [3][4][5][6][7].…”

“…Alternatively the geometry of the surgical region can be obtained from the patient's image dataset, thus providing a patient-specific model. Such models define PAB and stent-PDA size by internal luminal dimensions which is in contra-distinction to the surgical procedure, being based on calibration of the external PAB dimension [1,2]. This difference in quantifying PAB dimension and the fact that these models are computationally demanding limit their clinical application.…”