Surgical Treatment Following Stent Angioplasty for High-Risk Neonates With Critical Coarctation of the Aorta.

BACKGROUND: Neonatal coarctation of the aorta (CoA) is primarily treated by surgical repair. However, under certain high-risk constellations, initial stent angioplasty may be considered followed by surgical repair. We report our experience with this staged approach. Methods: All patients undergoing surgical CoA repair following prior stenting at our institution between January 2011 and December 2019 were included in this retrospective analysis. The patients were classified to be at high risk because of cardiogenic shock, associated complex cardiac malformations, neonatal infection, necrotizing enterocolitis, and extracardiac conditions, respectively. Outcomes were analyzed and compared with neonates who underwent surgical CoA repair without prior stenting in the same observation period. RESULTS: Twenty-six neonates received stent implantation at a median age of 20 days (IQR 9-33 days). Subsequent surgical repair was conducted at an age of 4.2 months (IQR 3.2-6.1 months) with a median body weight of 5.6 kg (IQR 4.5-6.5 kg). Cardiopulmonary bypass was applied in 96% of cases. Extended end-to-end anastomosis was possible in 11 patients. Extended reconstruction with patch material was necessary in the remaining patients. One fatality (3.8%) occurred 33 days postoperatively. At a median follow-up of 5.2 years after initial stenting, all remaining patients were alive; 15/25 patients (60%) were free from re-intervention. Of note, re-intervention rates were comparable in neonates (n = 76) who were operated on with native CoA (28/74 patients; 38%; P = .67). CONCLUSIONS: Neonatal stent angioplasty for CoA results in increased complexity of the subsequent surgical repair. Nevertheless, this staged approach allows to bridge high-risk neonates to later surgical repair with reduced perioperative risk and acceptable midterm outcomes.

Intermediate monocytes exhibit higher levels of TLR2, TLR4 and CD64 early after congenital heart surgery.

INTRODUCTION: Congenital heart surgery with cardiopulmonary bypass (CPB) initiates an immune response which frequently leads to organ dysfunction and a systemic inflammatory response. Complications associated with exacerbated immune responses may severely impact the postoperative recovery. The objective was to describe the characteristics of monocyte subpopulations and neutrophils at the level of pattern recognition receptors (PRR) and the cytokine response after CPB in infants. METHODS: An observational cohort study was conducted between June 2016 and June 2017 of infants < 2 years of age, electively admitted for surgical correction of acyanotic congenital heart defects using CPB. Fourteen blood samples were collected sequentially and processed immediately during and up to 48 h following cardiac surgery for each patient. Flow cytometry analysis comprised monocytic and granulocytic surface expression of CD14, CD16, CD64, TLR2, TLR4 and Dectin-1 (CLEC7A). Monocyte subpopulations were further defined as classical (CD14++/CD16-), intermediate (CD14++/CD16+) and nonclassical (CD14+/CD16++) monocytes. Plasma concentrations of 14 cytokines, including G-CSF, GM-CSF, IL-1ß, IL-1RA, IL-4, IL-6, IL-8, IL-10, IL-12p40, IL-12p70, TNF-α, IFN-γ, MIP-1ß (CCL4) and TGF-ß1, were measured using multiplex immunoassay for seven points in time. RESULTS: Samples from 21 infants (median age 7.4 months) were analyzed by flow cytometry and from 11 infants, cytokine concentrations were measured. Classical and intermediate monocytes showed first receptor upregulation with an increase in CD64 expression four hours post CPB. CD64-expression on intermediate monocytes almost tripled 48 h post CPB (p < 0.0001). TLR4 was only increased on intermediate monocytes, occurring 12 h post CPB (p = 0.0406) along with elevated TLR2 levels (p = 0.0002). TLR4 expression on intermediate monocytes correlated with vasoactive-inotropic score (rs = 0.642, p = 0.0017), duration of ventilation (rs = 0.485, p = 0.0259), highest serum creatinine (rs = 0.547, p = 0.0102), postsurgical transfusion (total volume per kg bodyweight) (rs = 0.469, p = 0.0321) and lowest mean arterial pressure (rs = -0.530, p = 0.0135). Concentrations of IL-10, MIP-1ß, IL-8, G-CSF and IL-6 increased one hour post CPB. Methylprednisolone administration in six patients had no significant influence on the studied surface receptors but led to lower IL-8 and higher IL-10 plasma concentrations. CONCLUSIONS: Congenital heart surgery with CPB induces a systemic inflammatory process including cytokine response and changes in PRR expression. Intermediate monocytes feature specific inflammatory characteristics in the 48 h after pediatric CPB and TLR4 correlates with poorer clinical course, which might provide a potential diagnostic or even therapeutic target.