Pseudoaneurysm of the right ventricular outflow tract is a rare post-operative complication after congenital heart surgery.Reference Sah, Berdjis, Valdez and Gates1,Reference Pillai, Reddy, Kulkarni, Murthy and Cherian2
We herein present a 3-year-old girl with double outlet right ventricle associated with pulmonary atresia suffering from post-operative mediastinitis, and followed by a pulsating prominence of the anterior chest inflicted by the contained rupture of the right ventricular outflow tract.
Case report
A 3-year-old girl with double outlet right ventricle associated with pulmonary atresia successfully underwent Rastelli-type operation with a valved conduit made of the bovine pericardium® (Edwards Life Science Corporation, Irvine, CA, USA). However, she suffered from mediastinitis due to methicillin-resistant Staphylococcus aureus post-operatively. The patient was committed to 2 months of antibiotic therapy during which time debridement of the mediastinum was carried out. Then, we removed the infected extra-cardiac conduit using cardiopulmonary bypass as well as the infected sternum, the precordial skin, and the subcutaneous tissue and reconstructed the right ventricular outflow tract using a 0.6-mm-thick expanded polytetrafluoroethylene cardiovascular patch (W. L. Gore and Associates, Flagstaff, Arizona, United States of America). Finally, the anterior chest wall was reconstructed using the pectoral major musculocutaneous flap. Culture test indicated no bacteria present in all resected specimens during surgery, and post-operative antibiotics therapy using vancomycin and daptomycin was carried out for 1 month.
Six months after the surgery, a pulsating prominence on the upper half of the anterior chest suddenly occurred and progressed gradually for 2 weeks (Fig 1a and b). CT revealed a cavity surrounded by the musculocutaneous flap and right ventricular outflow tract, and communication between the right ventricular outflow tract and cavity (Fig 1c, arrow). Considering sudden rupture, we carried out an emergent surgery. On cardiopulmonary bypass with cannulation into the common carotid artery and the internal jugular vein, the bulging skin and the subcutaneous muscle flap were incised to find massive bleeding from the right ventricle. This cavity was caused by dehiscence of the sutures between right ventricle and extra-cardiac conduit. Methicillin-resistant S. aureus was detected from the cultures of the surgically removed patch. We successfully carried out the third reconstruction of right ventricular outflow tract using an oval Dacron patch covered by 0.6-mm-thick expanded polytetrafluoroethylene cardiovascular patch. Post-operative antibiotics were administered for 8 weeks. Although residual pressure gradient of right ventricular outflow tract was 20 mmHg by echocardiography at the time of discharge, now she is doing well without recurrent prominence of the anterior chest wall.
(a and b) After the surgery for mediastinitis, pulsating prominence on the anterior chest without sternum suddenly occurred. (c) CT showed a cavity surrounded by the musculocutaneous flap in front of the RVOT, and blood communication between the RVOT and the cavity (arrow). RVOT = right ventricular outflow tract.
Comment
Rupture of the right ventricular outflow tract suture line creating a pseudoaneurysm is a rare complication after reconstruction using a patch or conduit.Reference Sah, Berdjis, Valdez and Gates1,Reference Pillai, Reddy, Kulkarni, Murthy and Cherian2 The incidence of pseudoaneurysm of the right ventricular outflow tract and the developmental risk factors are not known, although elevated right ventricular pressure or infection has been previously implicated.Reference Levine, Mayer, Keane, Spevak and Sanders3 In our case, we surgically removed the infected sternum, reconstructed the anterior chest wall using musculocutaneous flap, and reconstructed the right ventricular outflow tract. However, we could not control the mediastinitis by the first procedure, which led to a small dehiscence along suture site of right ventricular outflow tract. This patient is a compromised host because of chromosomal abnormality, and the duration of antibiotic therapy in the patients with chromosomal abnormality remains controversial. Moreover, homografts are not commercially available in Japan and autologous pericardium was also not available due to severe adhesion. In addition to this complication, high right ventricle pressure due to the residual pulmonary stenosis might contribute to the dramatic prominence of the anterior chest wall. Fortunately, severe adhesion between the right ventricular outflow tract and muscle flap made her haemodynamically stable. To the best of our knowledge, the rupture of right ventricular outflow tract contained with a muscle flap previously reconstructed for methicillin-resistant S. aureus mediastinitis has not been previously reported in the literature.
In this case, we could recognise the contained rupture by progressive prominence of the anterior chest wall at an early stage, and we could safely perform the 3rd reconstruction of right ventricular outflow tract. Pseudoaneurysms are potentially life-threatening if not surgically treated and require prompt and precise diagnosis. CT was a useful method to diagnose her contained rupture and to provide helpful information for reoperation.
Acknowledgements
We would like to thank Editage (www.editage.com) for English language editing.
Financial support
This research received no specific grant from any funding agency, commercial, or not-for-profit sectors.
Conflicts of interest
None.
