Norwood Operation with Right Ventricular-Pulmonary Artery Shunt Versus Comprehensive Stage II After Bilateral Pulmonary Artery Banding Palliation

As a strategy for the primary Norwood operation, the right ventricular-pulmonary artery shunt is associated with satisfactory early outcome. However, use of this shunt after bilateral pulmonary artery banding remains controversial. This study compared the operative outcomes and late hemodynamics in patients who underwent the Norwood operation, preceded by bilateral pulmonary artery banding, with a right ventricular-pulmonary artery shunt or with bidirectional Glenn anastomosis (comprehensive stage II strategy). We retrospectively reviewed 38 patients who underwent the Norwood operation preceded by bilateral pulmonary artery banding between 2004 and 2017. Of these, 17 underwent the Norwood operation with a right ventricular-pulmonary artery shunt (Group S), whereas 21 underwent the comprehensive stage II strategy (Group G). 5 years after the Norwood operation, 10 (60%) and 17 (81%) patients in Group S and Group G, respectively, underwent the Fontan procedure. Group S showed significantly lower pressure in the superior vena cava after bidirectional Glenn anastomosis than Group G (13 ± 2 mmHg vs. 18 ± 3 mmHg; p < 0.01), but pressures were similar after the Fontan procedure. The right ventricular end-diastolic volume at 1 year post-Fontan procedure was significantly higher in Group S than in Group G (142 ± 41% vs. 91 ± 28%; p < 0.01). In terms of early outcomes, the Norwood operation with a right ventricular-pulmonary artery shunt enabled low pressure in the superior vena cava, but in the long term, this shunt adversely influenced the right ventricular volume.

Presurgical Use of Hypoxic Mixture for Systemic Perfusion Improvement in Neonates With Complex Congenital Heart Disease: A Systematic Review and Meta-Analysis

Oxygen therapy is essential for the survival of preterm babies and critically ill newborns; however, it has the potential to cause harm through hypoxemia or hyperoxemia. Newborns with complex congenital heart diseases (CHD) suffer from oxygen fluctuations due to the disease and its treatments, altering pre and postnatal development. The objective of this study is to evaluate the evidence for using a hypoxic mixture to decrease pulmonary over-circulation and improve systemic perfusion before surgical interventions in newborns with complex CHD that course with pulmonary over-circulation and systemic hypoperfusion. A search was conducted in PubMed, EMBASE, LILACS, Scielo, Taylor and Francis, SAGE, and Science Direct databases from 2000 to 2022 by two independent authors, including articles with hypoxic mixture treatment in observational studies or trials, with pre-treatment and post-treatment measurements in the same patient, or two groups or more comparisons. Six articles were selected, with a total of 75 patients. The primary outcome was improved systemic circulation and decreased pulmonary over-circulation measured directly with Qp/Qs and indirectly with oxygen saturation and cerebral near-infrared spectroscopy (NIRS). In addition, we performed a meta-analysis for oxygen saturation and cerebral NIRS. Oxygen saturation was the value uniformly reported; three studies reported a significantly lower oxygen saturation after the hypoxic mixture. The cerebral NIRS was measured in 4 studies, with inconsistent results. After using the hypoxic mixture, the Qp/Qs calculation was lower in the two studies but was not statistically significant. The meta-analysis for oxygen saturation showed a fixed effect post-hypoxic therapy of -0.7 (-1.06; -0.35), p < 0.001. The meta-analysis of two studies that measured cerebral NIRS did not show a statistically significant difference at 12 and 24 hours. In conclusion, this is the first systematic review and meta-analysis regarding the pre-operative use of hypoxic gas mixtures for newborns with complex congenital heart disease. Treatment results in lower oxygen saturations, but there is a lack of evidence of improvement in systemic perfusion. The utilization of this therapy is controversial, and better evidence is necessary.

A valuable echocardiographic indicator for the optimal tightness of bilateral pulmonary artery banding

OBJECTIVES

The optimal tightness of bilateral pulmonary artery banding (BPAB) is considered to balance not only systemic-to-pulmonary blood flow but also each pulmonary blood flow, which is still challenging. To achieve them, we adopt the end-diastolic velocity (EDV) to the peak systolic velocity (PSV) ratio at BPAB with intraoperative epicardial echocardiography. We evaluated the usefulness of the EDV to PSV ratio and the patient outcomes.

METHODS

34 patients underwent BPAB with this indicator and using a looped polytetrafluoroethylene suture. The PSV and the EDV to PSV ratio with echocardiography were measured in the intraoperative, early postoperative and late postoperative period. Lung perfusion scintigraphy was performed to quantify flow to each lung.

RESULTS

There were 3 early deaths (< 30 days). Two patients required re-BPAB due to hypoxia. The intraoperative EDV to PSV ratios in the right and left were almost equal (0.50 ± 0.07 versus 0.51 ± 0.06, P = 0.73). There was no significant difference in the right and left EDV to PSV ratios throughout the postoperative course. The right PSV was smaller than the left PSV due to the Doppler angle intraoperatively (2.78 ± 0.57 versus 3.02 ± 0.50, P = 0.030). In addition, the PSV changed significantly until the late postoperative period (P < 0.001). Lung perfusion scintigraphy revealed only two patients had perfusion abnormalities.

CONCLUSIONS

Our clinical outcomes are satisfactory with low early mortality and a low rate of re-BPAB. The EDV to PSV ratio can be a reliable indicator to assess flow distribution to each lung and may be a valuable adjunct to achieve balanced systemic to pulmonary flow.

Reverse Remodeling of Pulmonary Arterioles After Pulmonary Artery Banding in Patients ≥ 2 Years Old with Severe Pulmonary Arterial Hypertension and Congenital Heart Disease

The purpose of this study was to evaluate the pathological changes of the pulmonary arterioles in patients ≥ 2 years of age who first underwent a pulmonary artery banding (PAB) procedure, followed by bidirectional Glenn or Fontan according to their specific conditions. This was a prospective study of 15 children diagnosed and treated with PAB at the Department of Cardiothoracic Surgery of Anzhen Hospital between January 2009 and December 2012. The percentage of media area (%MS) of pulmonary arteriole, the percentage of media thickness (%MT), and pulmonary arterial density (APSC) were calculated from lung tissue sections. Pulmonary artery pressure decreased significantly after PAB surgery (P < 0.01). Postoperative mean pulmonary artery pressure declined significantly (P < 0.01), the cardiothoracic ratio was reduced (P < 0.05), and percutaneous oxygen saturation (inhaled air) decreased to 80-85% (P < 0.01). %MT (from 35.1 ± 5.6% to 26.9 ± 4.3%, P < 0.01), %MS (from 51.4 ± 6.7% to 32.2 ± 7.4%, P < 0.01), and APSC (from 108.3 ± 38.5 to 83.6 ± 19.6, P < 0.01) were decreased significantly after PAB. Five patients underwent the bidirectional Glenn procedure and four underwent Fontan. In conclusion, the results suggest that PAB can reduce pulmonary artery pressure and that pulmonary arterial lesions can be reversed after PAB.

Bilateral Pulmonary Artery Banding in Ebstein's Anomaly With Circular Shunting

We present a case of critical Ebstein's anomaly with circular shunting, diagnosed in utero. The fetal cardiothoracic area ratio was elevated; tricuspid regurgitation and pulmonary regurgitation worsened with fetal hydrops. At 35 weeks 6 days of gestation, elective caesarean section delivery was performed. Planned bilateral pulmonary artery banding and pulmonary trunk ligation were performed as a palliative operation 4 hours after birth, with the infant in a stable condition. At age 5 days, we performed the Starnes operation. The postoperative course was uneventful and a bidirectional Glenn operation was performed at age 4 months.

Early Outcomes of Hypoplastic Left Heart Syndrome Infants: Meta-Analysis of Studies Comparing the Hybrid and Norwood Procedures

The hybrid strategy is an alternative to the traditional Norwood procedure for initial palliation of infants with hypoplastic left heart syndrome (HLHS) who are deemed to be at high surgical risk. Numerous single-center studies have compared the two procedures, showing similar early outcomes, although the cohort sizes are likely insufficiently powered to detect significant differences. The current meta-analysis aims to explore the early morbidity and mortality associated with the hybrid compared to the Norwood procedure. MEDLINE, Cochrane Libraries, and Embase were systematically searched, and 14 studies were included for statistical synthesis, comprising 263 hybrid and 426 Norwood patients. Early mortality was significantly higher in the hybrid patients (relative risk [RR] = 1.54, P < .05, 95% confidence interval [CI]: 1.02-2.34), whereas interstage mortality was comparable between the two groups (RR = 0.88, P > .05, 95% CI: 0.46-1.70). Six-month (RR = 0.89, P < .05, 95% CI: 0.80-1.00) and one-year (RR = 0.88, P < .05, 95% CI: 0.78-1.00) transplant-free survival was also inferior among the hybrid patients. Furthermore, the hybrid patients required more reinterventions following initial surgical palliation (RR = 1.48, P < .05, 95% CI: 1.09-2.01), although the two groups had comparable length of hospital and intensive care unit stay postoperatively. In conclusion, our results suggest that the hybrid procedure is associated with worse early survival compared to the traditional Norwood when used for initial palliation of infants with HLHS. However, due to the hybrid being used preferentially for high-risk patients, definitive conclusions regarding the efficacy of the procedure cannot be drawn.

Impact of Era, Type of Isomerism, and Ventricular Morphology on Survival in Heterotaxy: Implications for Therapeutic Management

BACKGROUND

Heterotaxy has been demonstrated to reduce survival. There are several different subgroups of patients, however, and no single study has had a large number of patients and analyzed survival across the different subgroups such as patients born in different eras, patients with right and left isomerism, and patients with biventricular or functionally univentricular hearts. This study pools previously reported data from Kaplan-Meier curves and performs such subgroup analysis.

METHODS

A systematic review of the literature was performed to identify studies reporting survival of patients with the so-called "heterotaxy" by means of Kaplan-Meier survival curves. Data were extracted from these survival curves and then pooled together. A polynomial regression was then used to generate a pooled survival curve. This was done for all patients, those born in a more recent era, those with right and left isomerism, and those with biventricular or functionally univentricular hearts.

RESULTS

Those born in the more recent era (after 2000) had increased survival compared to the overall cohort. Those with left isomerism tended to have a survival benefit compared to those with right isomerism until about 16 years of age, beyond which those with right isomerism developed a survival benefit. Those with biventricular hearts had a survival benefit compared to those with left isomerism.

CONCLUSION

Survival in the so-called heterotaxy syndrome is based on several factors, which include era of birth, sidedness of isomerism, and whether the heart is biventricular or functionally univentricular.