Impact of stent of ductus arteriosus and modified Blalock-Taussig shunt on pulmonary arteries growth and second-stage surgery in infants with ductus-dependent pulmonary circulation

Blalock-Taussig Shunt versus Ductal Stenting as Palliation for Duct-Dependent Pulmonary Circulation

Objectives

There is limited data published from outside North America and Europe comparing the outcomes of a modified Blalock-Taussig shunt (MBTS) and ductal stenting as the first palliative procedure for infants with duct-dependent pulmonary circulation. This study reports the National Heart Center's, in Muscat, Oman, experience in comparing the outcomes of these 2 interventions.

Methods

This retrospective study included all infants with duct-dependent pulmonary circulation who received either a MBTS or ductal stenting from 2016-2019. The primary outcomes were death or re-interventions. Secondary outcomes included death, subsequent re-interventions, survival to subsequent surgical intervention, survival to hospital discharge, post-procedural mechanical ventilation and duration of intensive care unit stay.

Results

A total of 71 patients were included in the study, 33 (46%) of whom received ductal stenting. The prevalence of the primary outcome (death or re-intervention) in the patent ductus arteriosus (PDA) stent group was 54.5% versus 31.6% in the MBTS group but this was not statistically significant (P = 0.06). There was no difference between the 2 groups in terms of time to next surgical intervention (P = 0.233). The PDA stent group had shorter post-procedural, mechanical ventilation and intensive care unit stay durations (P <0.05). Syndromic patients were at higher risk of mortality compared to non-syndromic patients.

Conclusion

MBTS and ductal stenting are both acceptable modalities as a palliative intervention for infants with duct-dependant pulmonary circulation. Syndromic patients are at higher risk of mortality. This can be considered an important factor for patient selection.

Stent Strut Dilation in Branch Pulmonary Artery Stenosis Following Stenting of Arterial Duct in Duct-dependent Pulmonary Circulation

To assess the feasibility and outcome of stent strut dilation after arterial duct stenting with associated branch pulmonary artery (BPA) stenosis. Stenting of arterial duct in infants with duct-dependent pulmonary circulation is technically challenging. The presence of BPA stenosis is a relative contraindication for stent implantation. Infants with duct-dependent pulmonary circulation and associated BPA stenosis were assessed either by transthoracic echocardiogram alone or additional computerized tomography angiogram when required. Following ductal stenting, the stent struts of the stenosed BPA were crossed with an additional 0.014″ coronary guide wire and dilated using coronary balloons (2.0 or 2.5 mm in diameter). Seventeen (12 male) patients were considered for the procedure. The median age and weight were 27 days (range 2-94) and 2.6 kg (range 2.2-5), respectively. Fourteen patients (82.4%) underwent stent strut dilation after arterial duct stenting. Struts to left pulmonary artery was opened in 9 (64.3%) and right pulmonary artery in 5 (35.7%). The mean systemic oxygen saturation increased from 66.23 ± 8.9% at baseline to 86 ± 2.2% immediately after the stent deployment and final saturations after stent strut dilation were 89.29 ± 4.3%. Angiographic pulmonary flow improved in all cases. Stent strut dilation could not be done in 3 patients due to unfavorable anatomy. One patient had acute stent thrombosis and died in the hospital. Two others died during follow-up, during an acute febrile illness and gastroenteritis. All survivors underwent cardiac surgery and were on regular follow-up. Strut dilation of BPA stenosis is feasible to augment pulmonary blood flow, following arterial duct stenting. This procedure may be useful in selected patients with BPA stenosis to have uniform growth of pulmonary arteries.

Stenting of the Patent Ductus Arteriosus: A Meta-analysis and Literature Review

Background

Patent ductus arteriosus (PDA) stent placement and systemic-pulmonary surgical shunt procedure can both be performed as palliation for infants with duct-dependent pulmonary circulation. The aim of this meta-analysis and literature review was to compare outcomes and study populations between the 2 methods as well as review the technical considerations and complications of PDA stenting.

Methods

A systematic search was conducted using the PubMed database and meta-analysis was performed. Risk ratio and mean difference were used to compare the reported outcomes of studies across patients receiving PDA stent and surgical shunt.

Results

In total, 1094 patients from 8 comparative observational studies were included. The PDA stent group had a lower mortality rate and a shorter hospital length of stay than the systemic-pulmonary surgical shunt group, although at the expense of increased reintervention rates. There were higher proportions of patients with single-ventricle physiology and single-source pulmonary blood flow in the surgical shunt group.

Conclusions

PDA stenting appears to be a noninferior or possibly superior method of palliation for duct-dependent pulmonary circulation compared with systemic-pulmonary surgical shunt, recognizing, however, that patients receiving surgical shunt more often had single-ventricle physiology or single-source pulmonary blood flow in this meta-analysis.

Blalock-Taussig Shunt versus Ductal Stent in the Palliation of Duct Dependent Pulmonary Circulation; A Systematic Review and Metanalysis

In infants with ductal dependent pulmonary blood flow, Blalock-Taussig (BT) shunt and Patent Ductus Arteriosus (PDA) stent, are two palliative procedures aimed to restore circulation. A systematic review and metanalysis was performed on studies comparing PDA stents and BT shunts, in accordance with PRISMA guidelines. Meta-analysis revealed the following; (1) a reduced risk of mortality [RR = 0.585 [0.399-0.859], (P = 0.006)], (2) a reduced risk of complications [RR = 0.523 [0.318-0.860], (P = 0.011), and (3) a reduced risk of ECMO use [R = 0.267 [0.101-0.706] (P = 0.008)], all in the stent group. Additionally, stent group showed higher post procedure oxygen saturation [SMD = 1.307 [95% CI 1.065-1.550], (P < 0.001)], and Nakata index [SMD = 0.679 95% CI [0.513 to 0.845], (P < 0.001)]. PDA stenting presents a viable alternative to BT shunt procedure with better post procedure stability.