Ductus Arteriosus Aneurysm and Pulmonary Artery Thromboses in a Protein S-Deficient Newborn

Ductus arteriosus aneurysm (DAA) asymptomatically occurs in newborn infants and resolves spontaneously. High-risk DAA with compression, rupture, and thrombosis requires early surgical intervention. Newborn infants have the highest risk of thrombosis among pediatric patients, but the genetic predisposition is difficult to determine in infancy. We herein report a neonatal case of massive thromboses in DAA and pulmonary artery. Desaturation occurred in an active full-term infant 2 days after birth. Echocardiography and contrast-enhanced computed tomography indicated thrombotic occlusion of the DAA and pulmonary artery thrombus. Urgent thrombectomy and ductus resection were successfully performed. After 6 months of anticoagulant therapy, the dissociated low plasma activity levels of protein S from protein C suggested protein S deficiency. A genetic study of PROS1 identified a heterozygous variant of protein S K196E, a low-risk variant of thrombophilia in Japanese populations. There have been seven reported cases with neonatal-onset symptomatic thromboses of DAA involving the pulmonary artery. All survived without recurrence after surgical intervention in five and anticoagulant therapy alone in two. Two newborns had a heterozygous methylenetetrahydrofolate reductase ( MTHFR ) variant, but information on thrombophilia was not available for any other cases. A genetic predisposition may raise the risk of DAA thrombosis, leading to rapid progression.

Successful Treatment of Saddle Pulmonary Thromboembolism in 23-Week Preterm Infant

Saddle pulmonary thromboembolism (PTE) is defined as a thromboembolism straddling the bifurcation of the main pulmonary artery trunk and it is rarely seen in extremely low birth weight infants (ELBWI). Saddle PTE is a critical disease that requires urgent treatment. However, the treatment guidelines for ELBWI are not established. We present the case of a 1-day-old preterm infant (gestational age 23 weeks) who showed sudden desaturation and pulmonary hypertension due to saddle PTE. A thrombus was observed in the bifurcation of the pulmonary artery. The blood flow to the pulmonary artery on the left side was interrupted, and the right side showed severe stenosis. Since the patient was an ELBWI in the acute phase, we decided to use recombinant tissue plasminogen activator (rt-PA) and administered a maintenance dose (0.08 mg/kg/hour), instead of the loading dose. After using rt-PA, the thrombus dissolved in 8 hours without adverse events. This case suggests that starting with a maintenance dose of rt-PA may be an effective treatment option for saddle PTE in ELBWI in the acute phase under the high risk of bleeding.

Ductus arteriosus-associated infective endarteritis: Lessons from the past, future perspective

BACKGROUND

Since routine clinical use of antibiotics as well as surgical and catheter-based closure of a patent arterial duct (PDA), PDA-associated infective endarteritis (PDA-IE) is rare but can still occur when the ductus is still open or as it closes. Thus, clinicians should maintain a high index of concern for patients with unexplained fever.

METHODS

We report on a PDA-IE in a young infant shortly after potentially delayed obliteration of a PDA. We discuss this case report by reviewing the literature in regard to the pathogenesis (infection primary or secondary to PDA thrombus formation), clinical (new heart murmur) and diagnostic findings (transthoracic echocardiography, total body MRI, laboratory findings), and clinical outcome during mid-term follow-up after successful antibiotic treatment.

RESULTS

A 7-week-old term infant with Staphylococcus aureus sepsis and a new heart murmur was diagnosed with PDA-IE by transthoracic echocardiography at the pulmonary artery end of an obliterated PDA. Broad diagnostic workup excluded other reasons for sepsis. After 4 weeks of antibiotic treatment the vegetation reduced in size and the infant recovered completely. A review of all cases of PDA-IE (in pediatric and adult patients) previously published was performed.

CONCLUSION

Nowadays, a PDA-IE is an extremely rare, but still life-threating condition that may even affect patients with a nonpatent ductus arteriosus shortly after its obliteration and should be considered as infective complication in preterms, neonates, and small infants. Therefore, in septic neonates with bacteremia, transthoracic echocardiography may be integrated in the diagnostic workup, especially by fever without source and clinical signs of IE such as a new heart murmur.