Introduction
Superior vena cava thrombosis following neonatal cardiac surgery is rare but may be a life-threatening complication. Reference Wilcox, Devejian, Sanchez, Edge, Larsen and Ambati1 Superior vena cava obstruction can present with superior vena cava syndrome in neonates undergoing cardiac surgery, with a reported incidence of 0.5%. Reference Sharoni, Erez, Birk, Katz and Dagan2 This case series describes superior vena cava thrombotic obstruction in four neonates following arterial switch operations for D-transposition of the great arteries, with the complication managed through transcatheter intervention. This case series highlights the benefits of early detection and immediate transcatheter balloon angioplasty over delayed intervention for superior short- and mid-term outcomes.
Case series
Case 1
A 2-day-old female infant [weight: 2.4 kg] was diagnosed with D-transposition of the great arteries with an intact interventricular septum, a large patent ductus arteriosus, and a small atrial septal defect. On the 3rd day of life, an atrial septostomy was performed, and on the 6th day, an arterial switch operation was conducted. During the cannulation of the superior vena cava, the posterior wall was injured and repaired with interrupted sutures. On the 2nd postoperative day, signs of superior vena cava obstruction were observed. Contrast computed tomography angiography revealed partial superior vena cava opacification with hypodense filling defects representing acute thrombosis. [Figure 1( a ), videoclip-1]. Cardiac catheterisation revealed total superior vena cava-right atrial junction occlusion with collateralisation from the internal jugular vein to the paravertebral veins and inferior vena cava. [Videoclip-2]. Sequential balloon dilation (2 mm × 12 mm, 3 mm × 12 mm coronary balloons, and 5 mm × 20 mm Tyshak Mini balloon) was done with aspiration of residual clots. A post-procedure angiogram showed improved flow with residual thrombi. An unfractionated heparin infusion was started that was later switched to low molecular weight heparin, and the baby was discharged. A follow-up after four weeks revealed distal superior vena cava stenosis due to scarring, which was confirmed via cardiac catheterisation (mean pressure gradient: 7 mmHg, diameter: 3.2 mm). Balloon dilation (5 mm × 20 mm, 7 mm × 20 mm ARMADA balloons) successfully restored flow with no residual stenosis. [Figure 1 ( b ),( c )]. Low molecular weight heparin was discontinued and replaced with aspirin. At the 3-month follow-up, transthoracic echocardiography showed a patent superior vena cava with normal laminar flow, and the child remained asymptomatic with no signs of increased intracranial pressure. During the 4-year follow-up, transthoracic echocardiography showed no restenosis in the superior vena cava or innominate vein, with the child demonstrating age-appropriate growth and neurodevelopment [Figure 1(d), videoclip-3].
A,B,C,D. Contrast computed tomography angiography showed partial superior vena cava opacification with hypodense filling defect [red arrow] representing acute thrombosis (a) , anteroposterior and lateral angiography showed restored flow through the superior vena cava with no residual stenosis (b,c) , 4th year follow-up transthoracic echocardiography showed patent superior vena cava (d) .
Case 2
A 1-day-old female baby [weight: 2.5 kg] was diagnosed with D-transposition of the great arteries, intact interventricular septum, restrictive PFO, and a patent ductus arteriosus. Balloon atrial septostomy was performed on the 2nd day of life, followed by arterial switch operations on the 8th day. Intraoperatively, during superior vena cava cannulation, a retraction injury to the right atrial was managed with primary continuous suture. On the 4th postoperative day, the neonate developed superior vena cava obstruction. Contrast computed tomography angiography showed significant obstruction due to a thrombus extending to the superior vena cava-right atrial junction [Figure 2( a )]. Cardiac catheterisation on the 6th postoperative day revealed a thrombus extending from the right and left internal jugular veins to the superior vena cava-right atrial junction. Balloon crushing of the thrombus was done using 3.5 x 20 mm and 5 x 20 mm coronary balloons. The patient was heparinised per protocol and then shifted to low molecular weight heparin infusion. Contrast computed tomography angiography performed 10 days after the intervention showed complete recanalisation of the superior vena cava [Figure 2 (b)]. The patient was discharged home on low molecular weight heparin, which was changed to aspirin after four months. At the 3-month follow-up, the child remained asymptomatic [normal head circumference and no vomiting], with the transthoracic echocardiography showing a patent superior vena cava. The child did not have restenosis of the superior vena cava. At the 3-year follow-up, transthoracic echocardiography confirmed a patent superior vena cava, and the child demonstrated normal growth and developmental milestones. [Videoclip-4].
A,B. Contrast computed tomography angiography showed significant obstruction due to a thrombus extending from the right internal and external jugular vein to the superior vena cava-right atrial junction (a) , follow-up contrast computed tomography angiography performed 10 days after cardiac catheterisation showing patency of superior vena cava.
Case 3
A 1-day-old male infant, weighing 3.1 kg, presented with D-transposition of the great arteries, restrictive PFO, a small ventricular septal defect, and a small patent ductus arteriosus. An atrial septostomy was performed on the third day of life, followed by an arterial switch operation on the seventh day. On the 5th postoperative day, contrast computed tomography angiography showed complete superior vena cava obstruction. An immediate cardiac catheterisation identified complete SVC thrombosis [Figure 3 (a) ]. The thrombus was crushed using coronary balloons sized 2.5/20 mm and 4/20 mm, along with a Sterling balloon of 6/40 mm [Figure 3 (b) , videoclip 4]. A hand injection showed free flow through the superior vena cava, right internal jugular vein, and innominate vein [Figure 3( c ), (d) , videoclip-5]. Residual small thrombi were observed distal to the catheter in the right internal jugular vein. A microcatheter was left in the innominate vein for 4 days, and unfractionated heparin infusion was administered. This was transitioned to low molecular weight heparin for 10 weeks and eventually replaced with aspirin. At the 3-month follow-up, the child remained asymptomatic, and transthoracic echocardiography demonstrated a patent superior vena cava without stenosis. At the most recent follow-up at 14 months, transthoracic echocardiography confirmed normal superior vena cava flow with no evidence of restenosis. The child continued to be asymptomatic and exhibited age-appropriate growth and neurodevelopmental milestones [Videoclip-6].
A,B.C,D. Angiography showed complete thrombosis of superior vena cava (a) , ballon dilation during cardiac catheterisation (b) , and successful recanalisation of the superior vena cava (c , d) .
Case 4
An 18-day-old boy [weight: 2.8 kg] presented with D-transposition of the great arteries, restrictive VSD, restrictive PFO, and no patent ductus arteriosus. An emergency balloon atrial septostomy was performed, creating only a 4 mm atrial septal defect. The baby underwent an emergency left Blalock–Thomas–Taussig shunt the following day to address persistent desaturation and haemodynamic instability. At 31 days of life, an arterial switch operation was performed. On day 50, the neonate was still on mechanical ventilation, and echocardiography showed absent flow in the superior vena cava. Contrast computed tomography angiography and angiography during an emergent cardiac catheterisation revealed complete occlusion of the superior vena cava-right atrial junction [Figure 4 (a) , (b) ]. Following a balloon angioplasty, an angiogram showed residual irregularities in the vessel [Figure 4 (c) , (d) ]. A site-directed thrombolysis with recombinant tissue plasminogen activator (ALTEPLASE) infusion was initiated, and flow into the superior vena cava was restored, although the vessel remained irregular. Eventually, the baby succumbed to sepsis secondary to immune deficiency and poor nutritional status due to persistent chylothorax and a prolonged ICU stay. The baby was investigated for genetic, metabolic, and haematologic causes of thrombophilia, including whole-exome sequencing, but all tests were unable to identify any reason for his extensive thrombosis.
A,B,C,D. Contrast computed tomography angiography (a) and angiography (b) showing a complete occlusion of the superior vena cava-right atrial junction. Balloon angioplasty (c) and recanalisation of superior vena cava with residual irregularities (d) .
Discussion
The primary risk factors for superior vena cava obstruction following cardiac surgery include iatrogenic injury during superior vena caval cannulation, endothelial cell injury from cardiopulmonary bypass, and the use of peripherally inserted central catheters during the perioperative period. Reference Pradhan, Batlivala, Pombo, Ollberding, Gao and Szugye3 The small calibre of the neonatal superior vena cava makes it particularly prone to occlusion. An intriguing aspect of this case series is that all the children had a primary diagnosis of D-transposition of the great arteries. This tendency may be attributed to the fact that arterial switch operation is the most commonly performed neonatal surgery at our centre, potentially accounting for the predominance of this subset of children who experienced superior vena cava thrombosis as a complication.
Critically ill neonates with superior vena cava thrombosis present with SVC syndrome and/or persistent chylothorax. Reference Kumar, Subramanian, Sathanandam, Alexander, Ali and Knott-Craig4 The acuity of the clinical presentation depends on the thrombosis rate and the time allowed for the collateral circulation to develop. Three of our cases presented with superior vena cava syndrome accompanied by persistent chylothorax, and one presented with chylothorax only. Managing infants with central body oedema and depleted intravascular volume from hypoalbuminemia due to chylothoraces is challenging. Persistent chylothoraces lead to the loss of immunoglobulins, lymphocytes, and nutrients, increasing the risk of opportunistic infections and death.
The therapeutic options for treating superior vena cava obstruction include systemic or direct thrombolytic therapy with anticoagulation, balloon dilation, stent implantation, thrombectomy, and surgical atrio-jugular bypass. Reference Kumar, Subramanian, Sathanandam, Alexander, Ali and Knott-Craig4,Reference Emsley, Haller and Arts5 Transcatheter management of post-surgical superior vena cava obstruction is effective and safe, leading to shorter hospital stays and reduced procedural morbidity compared to surgery. Reference Pradhan, Batlivala, Pombo, Ollberding, Gao and Szugye3 This case series involved transcatheter interventions that effectively restored superior vena cava flow, eliminating the need for surgical reconstruction. The failure of the 4th baby may be due to delayed intervention. This is the first case series utilising the balloon crushing technique for acute superior vena cava thrombosis in neonates after arterial switch operations. The first three surviving children remained under routine follow-up, without any evidence of re-stenosis, need for stent placement, or clinical signs of raised intracranial pressure, including increased head circumference or vomiting. Institutional ethical approval [MOH/CSR/CR/24/26] and parental consent for anonymised details were obtained for publication.
In conclusion, early diagnosis and prompt intervention for superior vena cava syndrome are crucial in preventing long-term complications. In these cases, CT angiography and cardiac catheterisation quickly identified the obstruction, allowing immediate transcatheter intervention. While thrombolytic therapy is the first-line treatment, transcatheter recanalisation serves as an effective alternative when resistance occurs. This highlights transcatheter techniques as a viable option to surgical interventions for superior vena cava obstruction in paediatric patients.
Supplementary material
The supplementary material for this article can be found at https://doi.org/10.1017/S104795112510989X.
Acknowledgements
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Financial support
This research received no specific grant from any funding agency, commercial or not-for-profit sectors.
Competing interests
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