Clinical Spectrum of Total Anomalous Pulmonary Venous Drainage: A Case Series

Introduction

Total anomalous pulmonary venous drainage (TAPVD) is a critical congenital heart defect in which all pulmonary veins drain into the systemic circulation rather than the left atrium, making survival dependent on maintaining atrial communication. This rare condition occurs in 7–9 per 100,000 live births, representing 0.7%–1.5% of all congenital heart diseases.^[1] Without intervention, mortality reaches 80% in the first year of life, though recent surgical advances have significantly improved outcomes.^[2]

In low- and middle-income countries (LMICs), access to comprehensive cardiac care remains limited, impacting early diagnosis and timely intervention.^[3] Surgical outcomes for TAPVD exhibit marked disparities across different settings. In high-income countries, early surgical intervention has achieved favorable results, with reported early mortality rates of 12% at 3 months and long-term survival of 78% at 20 years, where the mean age at operation was 46 days.^[4] In contrast, LMICs face greater challenges, with one study reporting a mean age at operation of 10.8 months and early postoperative mortality of 12.5%,^[5] while another documented inhospital mortality of 19.5%.^[6] These delayed presentations and higher mortality rates in resource-limited settings reflect systemic barriers, including late diagnosis, limited access to specialized cardiac centers, and challenges in timely referral pathways. Early detection through pulse oximetry screening has proven effective in high-income countries, and similar programs are being implemented in Indonesia despite operational challenges.^[7]

We present two cases from a tertiary cardiac center in an LMIC that illustrate the clinical spectrum of TAPVD, from severe cardiac presentation with prolonged intensive care course to supracardiac type with rapid recovery. These cases uniquely demonstrate the contrasting impact of atrial septal defect (ASD) size and pulmonary hypertension severity on perioperative outcomes, perioperative management protocols adapted for resource-limited settings, practical surgical decision-making considerations, and the importance of early detection and timely intervention in improving survival.

Case Report

Case 1

A 15-month-old boy weighing 5.3 kg presented with tachypnea since birth and recurrent pneumonia since 6 months of age. Physical examination revealed oxygen saturation of 70–85% on room air with mild cyanosis. Echocardiography demonstrated intracardiac TAPVD with moderate secundum ASD (0.80 cm) showing right-to-left shunt, severe tricuspid regurgitation (peak gradient: 84 mm Hg), and left ventricular ejection fraction (89%). Chest radiography showed cardiomegaly with right atrial/ventricular enlargement and increased bronchovascular markings. Multi-slice computed tomography confirmed intracardiac TAPVD with right atrial and ventricular dilatation. Cardiac catheterization revealed all pulmonary veins draining to the coronary sinus, then the right atrium, with severe pulmonary hypertension. Preanesthetic evaluation classified him as ASA 3 with anemia (Hb: 10.2 g/dL) and metabolic acidosis (arterial blood gas: pH 7.31, pO₂: 55 mm Hg, HCO₃⁻: 17.6 mmol/L, BE: −8.7, SO₂: 85%) [Figures 1 and 2].

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The surgical procedure included pulmonary venous rerouting to the left atrium with patch closure of ASD (with fenestration), tricuspid valve repair using the De Vega technique, patent ductus arteriosus ligation, and placement of an intrapericardial pigtail, right intrapleural drain, and substernal drain. Intraoperative peritoneal dialysis was initiated considering postoperative volume overload and pulmonary hypertension risks. The blood products administered included 150 mL of fresh frozen plasma, 300 mL of packed red cells, and 78 mL of platelet concentrate. Estimated blood loss was 100 mL with 250 mL of urine output.

The patient experienced a complicated postoperative course with persistent ventilator dependence, peritoneal dialysis requirement for fluid balance, hemodynamic instability, fluctuating fever, diarrhea, and tachycardia episodes reaching 200 bpm. Bilateral rhonchi developed with increased secretions. Laboratory findings showed progressive leukocytosis and elevated inflammatory markers. Sputum culture grew Pseudomonas oryzihabitans, which was resistant to multiple antibiotics. The patient was successfully extubated on postoperative day 11, transitioned to a nasal cannula, and gradually weaned from oxygen support before stable discharge.

Case 2

A 6-year-old boy, weighing 11.5 kg (underweight) and 101.3 cm in height (stunted), presented with easy fatigability for 2 years prior. The physical examination showed no cyanosis, with an oxygen saturation of 98% at rest. Echocardiography revealed supracardiac/mixed TAPVD with large ASD (1.3 cm) showing bidirectional shunt, moderate tricuspid regurgitation (peak gradient: 24 mm Hg), and left ventricular ejection fraction (66%). Cardiac catheterization confirmed that all pulmonary veins drained to the coronary sinus, then the right atrium, with partial drainage through the vertical vein to the innominate vein. Chest radiography showed increased pulmonary vascularity with right atrial enlargement. Multi-slice computed tomography revealed mixed-type findings, including right atrial/ventricular dilatation.

Intraoperative findings included an enlarged heart with secundum ASD and all four pulmonary veins draining to the superior vena cava (SVC) near the SVC-right atrial junction (dominant supracardiac type). Pulmonary venous rerouting to the left atrium was performed using a pericardial patch with ASD closure. Intrapericardial pigtail and intrapleural drains were placed. Blood products included 142 mL of packed red cells and 320 mL of platelet concentrate, with a total diuresis of 400 mL and an estimated blood loss of 150 mL [Table 1 and 2].

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The patient had an uncomplicated recovery with extubation on postoperative day 2, chest drain removal on day 3, early mobilization on day 3, and stable discharge on day 4 with mild incisional pain as the only complaint. Postoperative arterial blood gas showed pH 7.41, pCO₂: 35.5 mm Hg, pO₂: 563 mm Hg, HCO₃⁻: 22.8 mmol/L, BE: −2, SO₂: 100% indicating adequate oxygenation. Intraoperative transesophageal echocardiography confirmed an intact ASD patch without residual flow, trivial tricuspid regurgitation, and all pulmonary veins draining to the left atrium with continuous flow.

Discussion

This case series presents two pediatric patients with contrasting presentations and outcomes of TAPVD. Case 1 involved a 15-month-old with cardiac TAPVD, moderate ASD (0.8 cm), and severe pulmonary hypertension (tricuspid regurgitation gradient: 84 mm Hg), resulting in a complex intensive care unit (ICU) course with prolonged mechanical ventilation, peritoneal dialysis, and nosocomial infection. Case 2 presented a 6-year-old with supracardiac TAPVD, large ASD (1.3 cm), and mild pulmonary hypertension (gradient: 24 mm Hg), achieving rapid recovery with extubation on day 2 and discharge on day 4. This pattern was evident where large ASD with mild pulmonary hypertension allowed rapid recovery versus moderate ASD with severe pulmonary hypertension requiring complex postoperative care.

In TAPVD, all pulmonary venous return is directed to the right side, making atrial communication the sole pathway for oxygenated blood to reach the left atrium and systemic circulation. Without atrial communication, this condition is incompatible with neonatal survival.^[6] Classic clinical findings demonstrate that nonrestrictive ASD allows better blood mixing and more stable systemic cardiac output, enabling some non-obstructive patients to survive longer into childhood.^[7] This pattern was evident in Case 2 (large ASD, mild pulmonary hypertension, rapid recovery) versus Case 1 (moderate ASD with severe pulmonary hypertension and complex ICU course). Reports of adolescent/adult patients with uncorrected TAPVD confirm this pattern, where rare long-term survival typically occurs with non-obstructive anatomy plus large ASD, and surgical correction at advanced age can still provide meaningful hemodynamic improvement.^[7,8]

Perioperative management focuses on reducing pulmonary vascular resistance and supporting right ventricular function. The European Society of Cardiology/European Respiratory Society 2022 recommendations emphasize optimizing oxygenation and ventilation while avoiding hypoxemia, hypercarbia, acidosis, and hypothermia that can increase pulmonary vascular resistance.^[9] Inhaled nitric oxide serves as a selective pulmonary vasodilator for pulmonary hypertension crises and post-bypass transitions. Phosphodiesterase type 5 (PDE-5) inhibitors such as sildenafil and endothelin-receptor antagonists should be considered as combination therapy when weaning inhaled nitric oxide. Milrinone provides beneficial inodilator effects, reducing pulmonary vascular resistance while supporting contractility. Systemic pressure should be maintained above pulmonary pressure through vasopressor titration. Adequate sedation and muscle relaxation prevent agitation-triggered crises, and early extubation should be targeted when the patient is stable.^[9] These principles were applied in Case 1 (inhaled nitric oxide, milrinone, protective ventilation strategy, and ASD fenestration as a “pop-off”) and Case 2 (mild pulmonary hypertension, allowing for early extubation and rapid recovery).

Pulmonary venous obstruction following TAPVD repair remains a major concern. Consistently reported risk factors include preoperative obstruction, neonatal age, low birth weight, infracardiac/mixed types, and prolonged cardiopulmonary bypass time.^[10] Pulmonary veno-occlusive disease (PVO) correlates with mortality, reintervention, and prolonged ICU stay.^[11] Sutureless technique, which avoids direct suturing on vein walls during pulmonary vein-left atrial anastomosis, was introduced to reduce anastomotic restenosis.^[12] A 2022 meta-analysis revealed that the sutureless technique is associated with reduced early and overall mortality, fewer PVO cases, and lower reoperation rates compared to conventional techniques. However, the evidence quality is primarily derived from retrospective studies.^[12] Recent 2024 pediatric cohort findings confirm that PVO remains a global concern requiring regular postoperative follow-up, especially in high-risk cases.^[13] For our two cases, anatomy and pulmonary vein size did not indicate a primary sutureless approach; however, this technique warrants consideration in high-risk neonates with small/fragile pulmonary veins, severe obstruction, or redo cases to minimize anastomotic stenosis.^[13]

Although scarce, reports of adult patients with non-obstructive TAPVD surviving into the second through seventh decades of life have been published.^[7,8] The physiological core remains the same: Large nonrestrictive ASD allows adequate mixed flow for systemic cardiac output, delaying severe symptoms; however, they remain at risk for progressive pulmonary hypertension, arrhythmias, and right heart failure, so surgical correction is still recommended when diagnosed.^[7,8] After repair in adulthood, several series report significant arrhythmia burden during long-term follow-up, making rhythm monitoring an important postoperative component.^[14] These findings align with our Case 2, showing prolonged preoperative survival due to a large ASD and the absence of obstruction, with good post-correction outcomes, but requiring long-term monitoring for complications.

Based on contemporary literature and our experience, several key recommendations emerge. Early detection through pulse oximetry screening for critical congenital heart disease using updated algorithms, combined with clinical examination and rapid echocardiography referral when abnormal, has proven to improve early detection and reduce infant mortality.^[15] For diagnosed TAPVD, especially with signs of obstruction or pulmonary hypertension, early correction is standard, with delay only for brief stabilization if necessary.^[9] Perioperative pulmonary hypertension management should include optimization of oxygenation/ventilation, inhaled nitric oxide as a selective pulmonary vasodilator, inodilators such as milrinone, and PDE-5 inhibitors as transitional/adjunctive therapy.^[9] Surgical strategy should be individualized with consideration of sutureless technique for high PVO risk patients, especially for neonates/infants with small pulmonary veins, preoperative obstruction, or redo cases.^[12] Postoperative surveillance requires serial echocardiography, especially in the first 6–12 months, to capture early PVO that predicts reoperation, with particular attention to high-risk patients.^[6,13] Long-term monitoring should include rhythm assessment and right heart function evaluation, as arrhythmia burden, particularly intra-atrial reentrant tachycardia, is not uncommon in post-repair survivors.^[14] This case series demonstrates contrasting TAPVD presentations with comprehensive diagnostic evaluation and detailed perioperative protocols, but limitations include a small sample size and short follow-up, restricting generalizability.

TAPVD represents a critical congenital heart defect requiring urgent diagnosis and surgical intervention. The key determinants of outcome include ASD size, degree of pulmonary hypertension, and prevention of postoperative pulmonary venous obstruction. These cases demonstrate the importance of early detection, timely surgical correction with an individualized approach, comprehensive perioperative management of pulmonary hypertension, and vigilant long-term surveillance for complications. Successful outcomes depend on systematic implementation of evidence-based strategies across the entire care pathway from neonatal screening to long-term follow-up.