Introduction
Pulmonary homografts are widely used for right ventricular outflow tract reconstruction following the initial repair of complex CHD such as tetralogy of Fallot. Homografts offer several advantages including excellent hemodynamic performance, low transvalvular gradients, and favourable biocompatibility due to their human origin. They are particularly beneficial in complex right ventricular outflow tract reconstructions where both valvular and conduit function are required, offering superior anatomical conformity compared to synthetic alternatives. Reference Poynter, Eghtesady and Devaney1 In addition, homografts demonstrate lower rates of thromboembolism and endocarditis compared to mechanical prostheses and stented bioprosthetic valves, making them a preferred choice in paediatric and young adult populations. Reference McElhinney, Hellenbrand and Zahn2 Clinical studies have shown that homografts can provide satisfactory mid- to long-term durability, especially in older children and adults, with acceptable rates of freedom from reintervention at 10 years post-implantation. Reference Brown, Ruzmetov and Rodefeld3 Their resistance to infection makes them particularly valuable in reoperative settings or in patients with prior endocarditis. Reference Pacifico, Bargeron and Kirklin4 However, long-term complications including conduit stenosis, calcification, and degeneration are well described. In contrast, pseudoaneurysm formation at the anastomotic site is a rare but potentially life-threatening complication. Herein, we report a case of pseudoaneurysm developing at the right ventricular anastomosis of a pulmonary homograft one year after implantation.
Case presentation
A male child born in January 2018 was diagnosed with tetralogy of Fallot and underwent complete surgical repair in January 2020 at the age of two. The operation included VSD closure and transannular patch enlargement of the right ventricular outflow tract. In May 2024, the patient underwent right ventricular outflow tract reconstruction with a 17 mm valved pulmonary homograft (Stembio®) due to progressive pulmonary valve regurgitation. He was discharged uneventfully 10 days postoperatively. At routine follow-up in January 2025, transthoracic echocardiography revealed a pseudoaneurysm at the proximal anastomotic site between the right ventricle and the homograft (Figure 1). Urgent reoperation was performed. Intraoperative findings included dehiscence of the proximal homograft anastomosis with formation of a pseudoaneurysm, which was partially self-contained. Surgical repair was performed using a bovine pericardial patch (Invengenx®) because autologous pericard was used in a prior operation (Figure 2). Reference Bhende, Sharma, Krishnakumar, Ramaswamy, Bilgi and Pathan5 The patient had an uneventful recovery and was discharged 5 days postoperatively.
( a). Transthoracic echocardiogram showing the pseudoaneurysm adjacent to the proximal homograft anastomosis (arrow).( b) . CT angiography demonstrating the pseudoaneurysm sac originating from the right ventricular outflow tract.
Intraoperative image showing proximal homograft anastomosis and pseudoaneurysm sac formation.
Discussion
Pseudoaneurysm formation after right ventricular outflow tract reconstruction with a pulmonary homograft is an uncommon yet potentially fatal complication. While conduit degeneration, calcification, and stenosis are well-recognised late outcomes in patients receiving homografts, anastomotic dehiscence leading to pseudoaneurysm is rarely reported—particularly in the paediatric population. Reference Brown, Ruzmetov and Rodefeld3
Several aetiological factors may contribute to pseudoaneurysm formation, including technical issues during anastomosis, structural degradation of homograft tissue, infection, and high RV pressures postoperatively. Reference McElhinney, Reddy, Moore and Hanley6 In our case, there was no evidence of infection, and the homograft appeared macroscopically intact, suggesting a likely mechanical or hemodynamic aetiology. One hypothesis is that progressive regurgitation and pressure overload may have exerted excessive mechanical stress on the proximal anastomosis, leading to dehiscence.
Although rare, there are sporadic reports in the literature highlighting similar complications. For instance, Coats et al. described pseudoaneurysm formation at homograft sites in congenital cases, emphasising the insidious nature of this condition and the role of imaging in early detection. Reference Coats, O’Sullivan and Chaturvedi7 Similarly, Al-Halees et al. reported homograft-related pseudoaneurysms requiring urgent surgical reintervention, underlining that these lesions can be silent until rupture or embolisation. Reference Al-Halees, Pieters and Sadeghi8
The role of imaging surveillance cannot be overstated. Transthoracic echocardiography is usually the first-line modality; however, in cases with suspected pseudoaneurysm, cross-sectional imaging such as CT angiography or cardiac MRI provides essential anatomical detail and guides surgical planning. Reference Bhatla, Ninan and Balaji9 In our patient, routine echocardiographic follow-up enabled timely diagnosis before clinical deterioration, averting a potentially catastrophic rupture.
Surgical management is the cornerstone of treatment. Various techniques have been described, including patch repair or graft replacement, depending on the location and extent of the defect. Reference Hraska, Photiadis and Sinzobahamvya10 In our case, a bovine pericardial patch was used successfully to reinforce the proximal anastomosis without replacing the entire conduit. This approach minimised surgical trauma and preserved homograft function.
Given the increasing use of homografts and other conduits in congenital heart surgery, this case underscores the importance of long-term, structured follow-up programmes with multidisciplinary input. Even in asymptomatic patients, vigilant surveillance and timely intervention can prevent devastating complications.
Conclusion
Pseudoaneurysm at the right ventricular anastomosis of a pulmonary homograft is a rare but serious complication. Surgical repair with the bovine patch used in this case provides a safe and effective treatment option. Vigilant follow-up with imaging remains critical for early diagnosis and management in such patients.
