Translocation of Prosthetic Aortic Valve in Advanced Prosthetic Valve Endocarditis

Abstract

Advanced prosthetic valve endocarditis is often associated with substantial destruction of the tissues adjacent to the prosthesis. Removal of the infected prosthesis and débridement of the infected tissues make implantation of a new prosthesis challenging. Herein, we discuss successful surgical aortic valve translocation in a 50-year-old man who had advanced acute prosthetic valve endocarditis with destruction of the aortic annulus. One year after being discharged from the hospital, the patient was asymptomatic with good exercise tolerance.

Advanced prosthetic valve endocarditis (PVE) associated with periprosthetic abscess and dehiscence of the prosthesis carries high morbidityand mortality rates.^1,2 Here, we describe the surgical management of apatient who had advanced PVE and a destroyed aortic annulus. The infected prosthesis was removed, and extra-anatomic implantation of a prosthetic aortic valve was performed.

Case Report

A 50-year-old man with aortic PVE of 6 weeks' duration was treated with intravenous antibiotics for infective endocarditis due to Streptococcus mitis. He developed cardiac failure with severe paravalvular leak and aortic root abscesses and was referred to our hospital for further management. One year earlier, the patient had undergone coronary artery bypass grafting and aortic valve replacement with a 23-mm prosthetic valve (St. Jude Medical, Inc.; St. Paul, Minn). Computed tomography now showed a patent graft of the left internal thoracic artery (LITA) to the left anterior descending coronary artery and patent saphenous vein grafts to the obtuse marginal and right coronary arteries (Fig. 1). Left ventricular function was mildly impaired, without regional wall motion abnormalities.

Fig. 1. Preoperative 64-slice computed tomography shows the position of the prosthetic aortic valve and the patent grafts to the native coronary vessels.

A redo sternotomy was performed. Dense pericardial adhesions were found. Cardiopulmonary bypass (CPB) was instituted via cannulation of the femoral artery and right atrium. The LITA pedicle was not dissected, due to the intrapericardial adhesions. Systemic hypothermia to 20 °C was achieved. Myocardial protection was provided via antegrade and retrograde delivery of cold-blood cardioplegic solution. The prosthetic valve showed dehiscence around half of its circumference, and it was explanted easily. The aortic annulus had been destroyed by the necrotic process from the infection. A large healed abscess involved the aortic root. Thorough débridement of the infected tissue of the annulus and the root was performed. The ostia of the left main and right coronary arteries were obliterated with running 5-0 Prolene suture (Ethicon, Inc., a Johnson & Johnson company; Somerville, NJ), and a 23-mm St. Jude prosthetic aortic valve was implanted at the level of the sinotubular junction by use of horizontal mattress sutures with pledgets (Figs. 2A and 2B). The sutures were placed from outside the aorta. The aortic cross-clamp time was 127 min, and the duration of CPB was 300 min. Three days of extracorporeal membrane oxygenation support was required to wean the patient from CPB. He spent 13 days in the intensive care unit, recovered well, and was discharged from the hospital on postoperative day 28. Intravenous antibiotics were continued for 6 weeks postoperatively. One year after discharge from the hospital, the patient was asymptomatic with good exercise tolerance.

Fig. 2. A) Postoperative computed tomography shows the translocation of the new prosthetic aortic valve above the annulus. B) Diagram of the operation shows the obliteration of the ostia of the native coronary arteries.

Discussion

Prosthetic valve endocarditis that involves the aortic valve can lead to extensive infection of the aortic root, including abscess formation, dehiscence of the prosthetic valve, and disruption of the ventriculo-aortic junction. Thorough débridement of all infected tissues at the time of reoperation is essential to the prevention of recurrent infection.

Aortic valve translocation was initially described in 1974 as a method by which to implant a new prosthetic valve in a patient who had infective endocarditis and a destroyed aortic root and annulus.³ Although the initial results with this technique were poor, they have improved. An operative mortality rate of only 14% and good long-term follow-up has been reported in 21 patients who underwent the procedure between 1980 and 1992.⁴ In those patients, a prosthetic tube graft was used for the implantation of the prosthetic valve. In our patient, we avoided the need for a prosthetic graft by implanting the new prosthesis at the level of the sinotubular junction. The tissue at this level was relatively healthy in our patient and provided a good site for extra-anatomic implantation.

Injury to a patent LITA graft at the time of 2nd sternotomy is associated with a substantial risk of morbidity and death. Perfusion of the LITA graft at systemic hypothermia of 20 °C has been used in complicated valve replacement after coronary surgery,⁵ and this step was very useful in our patient. Preserving the integrity of the patient's patent grafts was crucial. Multislice computed tomography was helpful in revealing the extent of infection in the aortic root and the location and patency of the grafts.

Aortic valve translocation can be a valuable surgical option in a patient who has a destroyed aortic annulus and patent coronary artery grafts.