Maintaining the adequacy of systemic oxygen delivery is of utmost importance, particularly in critically ill children. Renal oxygen extraction can be utilised as metric of the balance between systemic oxygen delivery and oxygen consumption. The primary aim of this study was to determine what clinical factors are associated with renal oxygen extraction in children after Norwood procedure.

Mechanically ventilated children who underwent Norwood procedure from 1 September, 2022 to 1 March, 2023 were identified as these patients had data collected and stored with high fidelity by the T3 software. Data regarding haemodynamic values, fluid balance, and airway pressure were collected and analysed using Bayesian regression to determine the association of the individual metrics with renal oxygen extraction.

A total of 27,270 datapoints were included in the final analyses. The resulting top two models explained had nearly 80% probability of being true and explained over 90% of the variance in renal oxygen extraction. The coefficients for each variable retained in the best were −1.70 for milrinone, −19.05 for epinephrine, 0.129 for mean airway pressure, −0.063 for mean arterial pressure, 0.111 for central venous pressure, 0.093 for arterial saturation, 0.006 for heart rate, −0.025 for respiratory rate, 0.366 for systemic vascular resistance, and −0.032 for systemic blood flow.

Increased milrinone, epinephrine, mean arterial pressure, and systemic blood flow were associated with decreased (improved) renal oxygen extraction, while increased mean airway pressure, central venous pressure, arterial saturation, and systemic vascular resistance were associated with increased (worsened) renal oxygen extraction.

Acute kidney injury is a common complication following the Norwood operation. Most neonatal studies report acute kidney injury peaking within the first 48 hours after cardiac surgery. The aim of this study was to evaluate if persistent acute kidney injury (>48 postoperative hours) after the Norwood operation was associated with clinically relevant outcomes.

Two-centre retrospective study among neonates undergoing the Norwood operation. Acute kidney injury was initially identified as developing within the first 48 hours after cardiac surgery and stratified into transient (≤48 hours) and persistent (>48 hours) using the neonatal modification of the Kidney Disease: Improving Global Outcomes serum creatinine criteria. Severe was defined as stage ≥2. Primary and secondary outcomes were mortality and duration of ventilation and hospital length of stay.

One hundred sixty-eight patients were included. Transient and persistent acute kidney injuries occurred in 24 and 17%, respectively. Cardiopulmonary bypass and aortic cross clamp duration, and incidence of cardiac arrest were greater among those with persistent kidney injury. Mortality was four times higher (41 versus 12%, p < 0.001) and mechanical ventilation duration 50 hours longer in persistent acute kidney injury patients (158 versus 107 hours; p < 0.001). In multivariable analysis, persistent acute kidney injury was not associated with mortality, duration of ventilation or length of stay. Severe persistent acute kidney injury was associated with a 59% increase in expected ventilation duration (aIRR:1.59, 95% CI:1.16, 2.18; p = 0.004).

Future large studies are needed to determine if risk factors and outcomes change by delineating acute kidney injury into discrete timing phenotypes.

Recurrent aortic arch obstruction following the Norwood procedure is recognised as an important complication. Balloon arch angioplasty is associated with a high recoarctation rate.

We sought to evaluate the prevalence and outcome of stent implantation for recoarctation in children following Norwood or Damus–Kaye–Stansel procedure over the past decade at a single national cardiology centre.

Of 114 children who underwent Norwood procedure or Damus–Kaye–Stansel procedure between January 2003 and June 2013, 80 patients survived. Of these 15 children underwent stent implantation for recoarctation. Six of these patients had previous balloon angioplasty. The median age at stent implantation was 4.4 months (range 2–82 months). The median peak aortic arch gradient at catheterisation decreased from 26mmHg (range 10–70mmHg) to 2mmHg (range 0–20mmHg). The median luminal diameter increased from 4.7 mm (range 3.2–7.9 mm) to 8.6 mm (range 6.2–10.9 mm). The median coarctation index increased by 0.49 (range = 0.24–0.64). A Valeo stent was employed in 11 children, a Palmaz Genesis stent in 2 patients, a MultiLink stent in 1 child, and a Jomed covered stent in 1 child. Two factors were associated with the need for stent placement: previous arch angioplasty (p valve < 0.001, χ-square 11.5) and borderline left ventricle (p = 0.04, χ-square = 4.1). Stent migration occurred in one child. There were two deaths related to poor right ventricular systolic function and severe tricuspid regurgitation. Six patients underwent redilation of the stent with no complications.

The prevalence of recurrent aortic arch obstruction following Norwood/Damus–Kaye–Stansel procedure was 18%. Stent implantation is safe and reliably eliminates the aortic obstruction. Redilation can be successfully achieved to accommodate somatic growth or development of stent recoarctation.

To identify interstage best practices associated with lower mortality, we studied National Pediatric Cardiology Quality Improvement Collaborative centres registry using a positive deviance approach.

Positive deviant and control centre team members were interviewed to identify potential interstage best practices. Subsequently, all collaborative centres were surveyed on the use of these practices to test their associations with centre mortality. Questionnaires were scored using Likert scales; the overall score was linearly transformed to a 0–100-point scale with higher scores indicating increased use of practices. Mortality was based on patients enrolled after a centre’s first year in the collaborative. Centre mortality rates were divided into tertiles. Survey scores for the low mortality tertile were compared with the other tertiles.

For this study, seven positive deviant and four control teams were interviewed. A total of 20 potential best practices were identified, including team composition, improvement practices, and parent involvement. Questionnaires were completed by 36/43 eligible centres, providing 1504 patients for analysis. Average survey score was 50.2 (SD 13.4). Average mortality was 6.1% (SD 4.1). There was no correlation between survey scores and mortality (r=0.14, p=0.41). The one practice associated with the low mortality tertile was frequency of discussion of interstage results: 58.3% of low mortality teams discussed results at least monthly versus 8.4% of the middle and high tertile centres (p=0.02).

Low-mortality centres more frequently discuss interstage results than high-mortality centres. Heightened awareness of outcomes may influence practice; however, further study is needed to understand the variation in outcomes across centres.

Although interstage mortality for infants with hypoplastic left heart syndrome has declined within the National Pediatric Cardiology Quality Improvement Collaborative, variation across centres persists. It remains unclear whether centres with lower interstage mortality have lower-risk patients or whether differences in care may explain this variation. We examined previously established risk factors across National Pediatric Cardiology Quality Improvement Collaborative centres with lower and higher interstage mortality rates.

Lower-mortality centres were defined as those with >25 consecutive interstage survivors. Higher-mortality centres were defined as those with cumulative interstage mortality rates >10%, which is a collaborative historic baseline rate. Baseline risk factors and perioperative characteristics were compared.

Seven lower-mortality centres were identified (n=331 patients) and had an interstage mortality rate of 2.7%, as compared with 13.3% in the four higher-mortality centres (n=173 patients, p<0.0001). Of all baseline risk factors examined, the only factor that differed between the lower- and higher-mortality centres was postnatal diagnosis (18.4 versus 31.8%, p=0.001). In multivariable analysis, there remained a significant mortality difference between the two groups of centres after adjusting for this variable: adjusted mortality rate was 2.8% in lower-mortality centres compared with 12.6% in higher-mortality centres, p=0.003. Secondary analyses identified multiple differences between groups in perioperative practices and other variables.

Variation in interstage mortality rates between these two groups of centres does not appear to be explained by differences in baseline risk factors. Further study is necessary to evaluate variation in care practices to identify targets for improvement efforts.

To evaluate differences in interstage growth of pulmonary arteries between use of polytetrafluoroethylene and femoral vein homograft as Sano shunt during stage-I Norwood palliation.

A retrospective review of all patients who survived to the second stage following Norwood–Sano operation at two institutions was performed. Either polytetrafluoroethylene or the valved segment of femoral vein homograft was used for construction of the Sano shunt. The size of pulmonary arteries was compared at pre-Glenn catheterisation.

A total of 48 neonates with the diagnosis of hypoplastic left heart syndrome or its variants comprised the study population. Femoral vein homograft of 5–6 mm diameter was used in 14 and polytetrafluoroethylene graft of 5 mm was used in 34 patients. The two groups were comparable in terms of preoperative demographics and age at time of pre-Glenn catheterisation (3.9±0.7 versus 3.4±0.8 months, p=0.06). Patients who received femoral vein homograft demonstrated a significantly higher pre-Glenn Nakata index [264 (130–460) versus 165 (108–234) mm2/m2, p=0.004]. The individual branch pulmonary arteries were significantly larger in the femoral vein group (right, 7.8±3.6 versus 5.0±1.2, p=0.014; left, 7.2±2.1 versus 5.6±1.9, p=0.02). There were no differences in cardiac index, Qp:Qs, ventricular end-diastolic pressure or systemic oxygen saturations.

Utilisation of a valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit during Norwood–Sano operation confers better interstage growth of the pulmonary arteries. Further studies are needed to evaluate the impact of femoral vein homograft on single ventricle function.

Patients undergoing the Norwood operation consume considerable healthcare resources; however, detailed information regarding factors impacting hospitalisation costs is lacking. We evaluated the association of postoperative complications with hospital costs.

In the present study, we utilised a unique data set consisting of prospectively collected clinical data from the Pediatric Heart Network Single Ventricle Reconstruction trial linked at the patient level with cost data for 10 hospitals participating in the Children’s Hospital Association Case Mix database during the trial period. The relationship between complications and cost was modelled using linear regression, accounting for the skewed distribution of cost, adjusting for within-centre clustering and baseline patient characteristics.

A total of 334 eligible Norwood records (97.5%) were matched between data sets. Overall, 82% suffered from at least one complication (median 2; with a range from 0 to 33). Those with complications had longer postoperative length of stay (25 versus 12 days, p<0.001), more total ventilator days (7 versus 5 days, p<0.001), and higher in-hospital mortality (17.6 versus 3.4%, p<0.006). Mean adjusted hospital cost in those with a complication was $190,689 (95% CI $111,344–$326,577) versus $120,584 (95% CI $69,246–$209,983) in those without complications (p=0.002). Costs increased with the number of complications (1–2 complications=$132,800 versus 3–4 complications=$182,353 versus ⩾5 complications=$309,372 [p<0.001]).

This merged data set of clinical trial and cost data demonstrated that postoperative complications are common following the Norwood operation and are associated with worse clinical outcomes and higher costs. Efforts to reduce complications in this population may lead to improved outcomes and cost savings.

We describe the experience from a single institution with the Norwood sequence of palliation for hypoplasia of the left heart, emphasizing complications related to placement of a conduit from the right ventricle to the pulmonary arteries and their management.

Between November, 2002 and January, 2006, we palliated 32 patients with hypoplastic left heart syndrome or its variants by placing a conduit from the right ventricle to the pulmonary arteries. We reviewed retrospectively the charts and angiograms from these patients.

Hospital survival after construction of the conduit was 90.6%. There were 3 interstage deaths, of which 2 were likely due severe obstruction of the conduit. Stents were implanted into the proximal or medial portions of the conduits of 3 patients. Early revision of the distal anastomosis, and shortening the conduit, was performed early postoperatively in 2 patients. So far, 24 out 26 survivors of the first stage underwent a bi-directional cavopulmonary anastomosis after a mean interval of 4.3 plus or minus 1.4 months. Of these, 3 required a semi-urgent second stage of palliation because of worsening cyanosis, with one patient dying after the second stage. Completion of the Fontan circulation by insertion of an extracardiac conduit was performed in 8 patients at the mean age of 19.8 plus or minus 2.2 months. We were able to achieve biventricular repair in 1 patient, with aortic atresia, hypoplastic arch and ventricular septal defect, 4.3 months after the initial palliative procedure. Overall survival of the whole cohort of 32 patients was 78.9%, plus or minus 7.8%, at 5 months, and 74.3%, plus or minus 8.6%, up to 25 months.

The introduction of the conduit placed from the right ventricle to the pulmonary arteries has led to an improved outcome in the complex entity of hypoplastic left heart syndrome and its variants. Stenosis of the conduit, nonetheless, may account for significant interstage morbidity, and often requires intervention or early installation of the second stage of palliation.