Delayed Infective Endocarditis with Mycotic Aneurysm Rupture below the Mechanical Valved Conduit after the Bentall Procedure

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1 Case Report Acta Cardiol Sin 2014;30: Delayed Infective Endocarditis with Mycotic Aneurysm Rupture below the Mechanical Valved Conduit after the Bentall Procedure Mei-Ling Chen, 1,3 Michael Y. Chen, 2,3 Wei-Hsian Yin, 4,5 Jeng Wei 4 and Ji-Hung Wang 2,3 The Bentall procedure is the gold standard for treating aortic dissection complicated with valvular and ascending aorta disease. Recent results for this procedure have been excellent; nearly 100% of patients remain free of infective endocarditis in long-term follow-up. We report a case of delayed Streptococcus agalactiae infective endocarditis complicated by mycotic aneurysm in a man who had undergone the Bentall procedure with a mechanical valve conduit 15 years previously. The mycotic aneurysm was located in the remnant aortic root, below the mechanical valve conduit, and later ruptured into the right atrium. The patient was treated conservatively and survived the acute period. Later, the aortic root defect was repaired successfully by means of a hybrid technique using a Amplatzer duct occluder. Key Words: Amplatzer duct occluder Aortic dissection Bentall technique Infective endocarditis Mycotic aneurysm INTRODUCTION Received: June 14, 2013 Accepted: November 13, Department of Internal Medicine; 2 Department of Cardiology, Buddhist Tzu Chi General Hospital; 3 Buddhist Tzu Chi University, Hualien; 4 Heart Center, Cheng Hsin General Hospital; 5 Faculty of Medicine, School of Medicine, National Yang Ming University, Taipei, Taiwan. Address correspondence and reprint requests to: Dr. Ji-Hung Wang, Department of Cardiology, Buddhist Tzu Chi General Hospital, No. 707, Sec. 3, Chung Yang Rd., Hualien 970, Taiwan. Tel: ext. 2227; Fax: ext. 3491; Financial support: None. All authors had access to the data and a role in writing the manuscript. The Bentall procedure was first described by Bentall and De Bono in Since then, composite replacement of the aortic valve and ascending aorta has been considered the gold standard for treating ascending aortic dissection complicated by aortic regurgitation. 1 Replacement of the aortic root using mechanical valved conduits with reimplantation of coronary arteries results in excellent long-term outcomes. Endocarditis and prosthetic failure are rare after use of a mechanical valved conduit: some studies have shown that almost 100% of patients were free from these complications. 2-6 However, infective endocarditis can develop in the mechanical valved conduit, and staphylococci are the predominant microorganism involved in this infection. 7 These infections occur most frequently during the early postoperative period. Infective endocarditis with Streptococcus agalactiae has been rarely reported among patients with mechanical valved conduits. Although it is an uncommon cause of endocarditis, it has a high mortality rate. 8 Cardiac surgery is usually required for infections of the mechanical valved conduit because of the high likelihood of resistant organisms and the possibilities of heart failure and embolization. Here, we report a case of very late infective endocarditis complicated by a mycotic aneurysm in a man who had undergone the Bentall procedure. The mycotic aneurysm was located below the mechanical valved conduit in a remnant aortic root and later ruptured into the right atrium. The shunt was successfully repaired by means of a hybrid 341 Acta Cardiol Sin 2014;30:

2 Mei-Ling Chen et al. procedure (open-chest transcatheter) using a Amplatzer duct occluder. CASE REPORT A 55-year-old man presented to our emergency department with a fever of 10 days duration. He had a history of type A aortic dissection 15 years earlier, for which he underwent the Bentall procedure. The Bentall mechanical valved conduit was connected to the sinotubular junction for replacement of the dissecting aortic root with coronary reimplantation, using the Cabrol technique. Ten days before admission, he developed fever, hemoptysis, and severe dyspnea. During hospitalization his temperature was 39.0 C, and cardiac examination revealed a clear metallic click without murmur. A subsequent blood culture grew S. agalactiae. Laterhe developed intermittent complete AV block and was transferred to the intensive care unit due to hemodynamic instability. A follow-up chest radiograph showed bilateral progressive alveolar infiltrates. Transthoracic echocardiography was performed to investigate the possibility of infective endocarditis and showed a highly mobile cm 2 vegetation attached to the right atrial septum, above the tricuspid septal leaflet. The vegetation was located near the remnant aortic root below the valved conduit (Figure 1A). Mechanical valve function was not affected, but a cardiovascular surgeon was consulted regarding the intermittent complete AV block. Conservative treatment with antibiotics was recom- A B C Figure 1. (A) Transthoracic echocardiogram showing vegetation (arrow) attached to the right atrial septum, above the septal leaflet of the tricuspid valve and near the remnant aortic root below the valved conduit. (B) Transesophageal echocardiogram (long-axis view) showing the remnant aortic root (dotted arrow) below the anastomotic site of the Bentall metallic valved conduit (arrow). (C, D) Rupture of the mycotic aneurysm (arrow) is clearly visible on a short-axis view; an abnormal, large shunt drains into the right atrium. D Acta Cardiol Sin 2014;30:

3 Delayed Infection after Bentall Procedure mended because the patient did not have decompensated heart failure. Thereafter, the AV block completely resolved 1 week after antibiotic treatment. The patient s condition stabilized, symptoms improved, and fever, dyspnea, and hemoptysis resolved. However, 2 weeks after admission a new-onset grade III systolic murmur was heard at the left lower sternal border. A transesophageal echocardiogram (TEE) showed a mycotic aneurysm at the remnant aortic root, below the anastomotic site of the mechanical valved conduit. Rupture of the mycotic aneurysm and an abnormal shunt that drained into the right atrium were clearly visible (Figure 1B, C, D). The patient and his family declined open heart surgery due to the high risk of the procedure. After 6 weeks of penicillin plus 3 weeks of gentamycin treatment the patient s infection was brought under control and he was discharged. However, 2 months later, he developed worsening heart failure characterized by exertional dyspnea and leg edema. TEE was used to evaluate the ruptured mycotic aneurysmandshowedanenlargedrupturewithasignificant shunt. Cardiac catheterization was arranged, and the ratio of pulmonary to systemic blood flow (Qp/Qs) was 6.3. Injection of contrast medium into the right heart during delayed cineangiography showed abnormal flow of contrast medium from the remnant aortic root back to the right atrium (Figure 2A). An aortogram showed minimal aortic regurgitation and no leakage of contrast medium from the mechanical valved conduit. After discussion with a specialized heart team comprising cardiac surgeons and interventional cardiologists, a hybrid procedure (open-chest transcatheter) using a Amplatzer duct occluder was chosen to close the site of the aneurysmal rupture. The procedure was performed after A B C Figure 2. (A) Injection of contrast medium into the right heart on delayed cineangiography reveals contrast medium shunting from the remnant aortic root into the right atrium (arrow, RAO view). (B) A surgical sketch illustrating closure of the defect using the Amplatzer duct occluder (arrow). (C, D) Postoperative TEE showing successful deployment of the Amplatzer duct occluder in the mycotic aneurysm (white arrow), with only minimal residual shunt flow draining into the RA (black arrow). TEE, transesophageal echocardiography. D 343 Acta Cardiol Sin 2014;30:

4 Mei-Ling Chen et al. the patient underwent midline thoracostomy and was placed on cardiopulmonary bypass (Figure 2B). Because retrograde delivery of the Amplatzer duct occluder through the mechanical valved conduit was impossible, an interventional cardiologist advanced the guidewire and sheath from the right femoral vein to the site of the rupture of the mycotic aneurysm. The sheath was then exchanged for the Amplatzer delivery catheter. After right atriotomy, and under direct supervision of a cardiovascular surgeon, the Amplatzer delivery catheter with the loaded occluder was gripped and pushed into the aneurysmal opening from the right atrium to the aortic root. The Amplatzer duct occluder was then released and successfully expanded under the guidance of TEE imaging (Figure 2C and D). The patient s postoperative course was uneventful, and he had a satisfactory recovery after discharge. At 6 months of follow-up, he has no symptoms of heart failure. DISCUSSION The incidence of complications related to the Bentall procedure is low post-surgically for the first ten years. Some patients develop infective endocarditis within 5 years after the procedure, most frequently involving infections near the junction between the aortic annulus and mechanical valved conduit. Our patient developed infective endocarditis caused by S. agalactiae 15 years after the procedure. S. agalactiae infection of the endocardium was extremely rare but its incidence has increased in recent years. It is more common among nonpregnant adults, elderly adults, and patients with chronic immunosuppressive diseases. 8 Surgical treatment of invasive infection is usually required due to the possibility of shock, intractable heart failure, persistent sepsis, and mycotic aneurysm. 7 After development of a mycotic aneurysm, antibiotics alone are not likely to eradicate the infection, and aortic root abscess frequently develops. However, patients who undergo surgical repair during the acute stage may develop serious complications such as acute renal failure, complete heart block and late pericardial tamponade requiring re-exploration of the mediastinum. Our patient was treated conservatively, as recommended by a consulting cardiac surgeon, and survived the acute period. However, he subsequently developed late sequelae of ruptured mycotic aneurysm, complicated by heart failure, after formation of a large leftto-right shunt. Repair of the rupture site was very challenging in our patient, and traditional surgical repair was not an option. Previous reports on the use of transcatheter closure (TCC) to repair the ruptured sinus of a valsalva aneurysm suggested the possibility of such treatment for the defect in our patient. Previous results were encouraging, and mid-term outcomes have been acceptable However, a pure percutaneous TCC approach would have been extremely technically demanding in this case, as the existing metallic valve above the rupture site prevented retrograde delivery of the closure device to the rupture site. Instead, a hybrid procedure in which a cardiovascular surgeon opened the chest and anterogradely delivered the closure device with the assistance of an interventionist was the best choice for our patient. The results have been excellent, which suggests that the present hybrid procedure is a promising treatment option for complications of this type. CONFLICTS OF INTEREST None. REFERENCES 1. Bentall H, De Bono A. A technique for complete replacement of the ascending aorta. Thorax 1968;23: Etz CD, Homann TM, Silovitz D, et al. Long-term survival after the Bentall procedure in 206 patients with bicuspid aortic valve. Ann Thorac Surg 2007;84: ; discussion Gelsomino S, Masullo G, Morocutti G, et al. Sixteen-year results of composite aortic root replacement for non-dissecting chronic aortic aneurysms. Ital Heart J 2003;4: Gelsomino S, Morocutti G, Frassani R, et al. Long-term results of Bentall composite aortic root replacement for ascending aortic aneurysms and dissections. Chest 2003;124: Hagl C, Strauch JT, Spielvogel D, et al. Is the Bentall procedure for ascending aorta or aortic valve replacement the best approach for long-term event-free survival? Ann Thorac Surg 2003;76: ; discussion. 6. Kallenbach K, Pethig K, Leyh RG, et al. Acute dissection of the ascending aorta: first results of emergency valve sparing aortic root Acta Cardiol Sin 2014;30:

5 Delayed Infection after Bentall Procedure reconstruction. Eur J CardioThorac Surg 2002;22: Ralph-Edwards A, David TE, Bos J. Infective endocarditis in patients who had replacement of the aortic root. Ann Thorac Surg 1994;58: Sambola A, Miro JM, Tornos MP, et al. Streptococcus agalactiae infective endocarditis: analysis of 30 cases and review of the literature, Clin Infect Dis 2002;34: Saner HE, Asinger RW, Homans DC, et al. Two-dimensional echocardiographic identification of complicated aortic root endocarditis: implications for surgery. J Am Coll Cardiol 1987; 10: Clarkson PM, Barratt-Boyes BG. Bacterial endocarditis following homograft replacement of the aortic valve. Circulation 1970; 42: Miller DC. Predictors of outcome in patients with prosthetic valve endocarditis (PVE) and potential advantages of homograft aortic root replacement for prosthetic ascending aortic valvegraft infections. J Card Surg 1990;5: Kerkar PG, Lanjewar CP, Mishra N, et al. Transcatheter closure of ruptured sinus of valsalva aneurysm using the Amplatzer duct occluder: immediate results and mid-term follow-up. Eur Heart J 2010;31: Zhao SH, Yan CW, Zhu XY, et al. Transcatheter occlusion of the ruptured sinus of valsalva aneurysm with an Amplatzer duct occluder. Int J Cardiol 2008;129: Chang CC, Chen ML, Chen TH, et al. Sinus of valsalva aneurysm with rupturing into the right atrium: a case report and review of the literature. Acta Cardiol Sin 2006;22: Acta Cardiol Sin 2014;30: