HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Johannes O. Bonatti Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Müller, L. C. Articles by Laufer, G. Search for Related Content PubMed PubMed Citation Articles by Müller, L. C. Articles by Laufer, G. Related Collections Valve disease

Ann Thorac Surg 2003;75:453-456
© 2003 The Society of Thoracic Surgeons

---

Original article: cardiovascular

Treatment of destructive aortic valve endocarditis with the freestyle aortic root bioprosthesis

^a Department of Cardiac Surgery, University of Innsbruck, Innsbruck, Austria
^b Department of Cardiology, University of Innsbruck, Innsbruck, Austria
^c Department of Microbiology, University of Innsbruck, Innsbruck, Austria

Accepted for publication July 10, 2002.

* Address reprint requests to Dr Müller, Department of Cardiac Surgery, University Hospital Innsbruck, Anichstrasse 35, A-6020 Innsbruck, Austria
e-mail: ludwig.mueller{at}uibk.ac.at

	Abstract

Top Abstract Introduction Patients and methods Results Comment References

 
BACKGROUND: Successful treatment of destructive aortic valve endocarditis with annular abscess formation requires extensive surgical debridement and reconstruction of the left ventricular outflow tract and aortic root. Homograft aortic roots are the conduits of choice, but because they are not available in all cases, alternative conduits are needed.

METHODS: Owing to its features, which are comparable to those of homografts, the Freestyle aortic root xenograft was used in 10 consecutive patients aged between 32 and 77 years. All patients had extensive abscess formation, 5 presented with prosthetic valve endocarditis, 2 had additional mitral valve endocarditis requiring partial leaflet resection and reconstruction, 1 patient had an additional fistula into the right atrium, and 1 required coronary bypass. One patient developed a septic ventricular septal defect and fistula into the right atrium with tricuspid valve endocarditis.

RESULTS: None of the patients required reoperation for bleeding. Two (20%) patients died in the postoperative period, 1 due to multiorgan failure, and 1 due to preexisting invasive pulmonary aspergillosis. At autopsy, neither had evidence of intrapericardial hematoma or suture dehiscence. One patient died 13 months postoperatively without clinical signs of valve dysfunction or recurrent endocarditis. All other patients are well at 12 to 42 months after surgery. Clinical examination and echocardiography at the most recent follow-up showed no signs of valve dysfunction, recurrent fistulation, or endocarditis.

CONCLUSIONS: The Freestyle aortic root appears to be an acceptable alternative to homografts in the treatment of severe endocarditis. Long-term valve durability in younger patients, however, remains to be determined.

	Introduction

Top Abstract Introduction Patients and methods Results Comment References

 
Native or prosthetic aortic valve endocarditis associated with destruction of the aortic annulus and subvalvular abscess formation with or without intra- or extracardiac fistula formation is a grave condition. In addition to effective antibiotic therapy, successful treatment of this condition presents a special surgical challenge, as it requires complete debridement of the necrotic and infected tissue, which results in extensive defects of the left ventricular outflow tract, the aortic annulus, the proximal aorta, as well as other intracardiac structures [1]. Various techniques have been employed for reconstruction of the aortic root, including repair with autologous or bovine pericardium and valve replacement by either mechanical or stented biological valves [2–4], and use of valved conduits [2, 4], homografts, or autografts [5–7].

Homografts are usually recommended because of their pliability and flexibility, which helps to create tension-free suture lines and fill abscess cavities with homograft tissue, as well as their resistance to infection. Xenograft aortic root prostheses may provide an alternative to homografts, which are of limited availability. We report our experience with xenograft reconstruction of the aortic root and the left ventricular outflow tract using theFreestyle Aortic Root Bioprosthesis (Medtronic, Inc., Minneapolis, MN) in patients with severe destructive endocarditis.

	Patients and methods

Top Abstract Introduction Patients and methods Results Comment References

 
From April 1998 to August 2001, 10 patients were treated. Patient characteristics and intraoperative findings are summarized in Table 1. Half of the patients presented with prosthetic valve endocarditis at 26, 62, and 67 days, and 5 and 8 years after aortic valve replacement, respectively. One patient with prosthetic valve endocarditis had a degenerated homograft, and 1 had undergone two previous aortic valve replacements already. The diagnosis of endocarditis was established on the basis of the clinical symptoms and the findings on transesophageal echocardiography. On account of grade III or IV aortic insufficiency, all patients were in New York Heart Association (NYHA) class IV.

Preoperative condition
Four patients were in acute heart failure; 1 of them was intubated and required mechanical ventilation due to severe pulmonary edema. Complete heart block was seen in 2 patients.

Intraoperative findings
All patients presented with acute necrotizing endocarditis with valvular vegetations and partial or total destruction of the annulus; 4 had additional subvalvular abscess formation. One patient had septic destruction of the membranous portion of the intraventricular septum, and in 1 perforation of the interatrial septum was noted. Three patients had fistulation from the aorta into the right atrium with perforation into the pericardial cavity in 1 of them. In 3 patients, additional severe (grade III or IV) mitral valve regurgitation was found, which was due to acute mitral valve endocarditis in 2 of them. One patient had tricuspid valve endocarditis.

Surgical treatment
All patients were put on mild to moderate hypothermic cardiopulmonary bypass using bicaval and ascending aortic cannulation. Myocardial protection was accomplished by retrograde (coronary sinus) and, if feasible, antegrade (by intubation of the coronary ostia) blood cardioplegia and topical cooling. Bypass times ranged from 203 to 381 minutes, and cross-clamping between 135 and 278 minutes. In 1 patient, hypothermic circulatory arrest for 26 minutes was required due to dissection of the ascending aorta.

After aortic cross-clamping, complete transection of the aorta was performed. After preliminary evaluation of the extent and severity of the disease, radical resection of all infected and necrotic tissue was performed without taking the extent of the created defect and later reconstruction or heart block into consideration. Typically, the full extent of the destructive process became evident only after radical debridement. Specimens of the valve and necrotic material were sent for bacteriological and histopathological investigation.

In all cases, reconstruction of the left ventricular outflow tract and the aortic root was accomplished by means of a Freestyle xenograft aortic root ranging from size 21 to 27 (median 23) as seen in Table 2. As the aortic annulus was invariably destroyed by the inflammatory process, full root replacement with reimplantation of the coronary ostia using the button technique had to be performed. The graft was sutured to the left ventricular outflow tract with either interrupted 4–0 polypropylene (Prolene), Teflon-coated polyester (Tevtek) sutures, or 4–0 polypropylene running sutures depending on the surgeon’s preference. Interrupted sutures were usually tied over a strip of pericardium to prevent leakage. 5–0 Prolene running sutures were used for implantation of the coronary ostia. The distal anastomosis between the xenograft and the ascending aorta was performed using a 4–0 Prolene running suture, which in all but the initial cases was buttressed by a strip of pericardium to prevent bleeding from the xenograft.

All patients were treated with appropriate antibiotic therapy according to the antibiogram (if a positive culture was obtained from blood or valve tissue) for at least 6 weeks postoperatively. In patients who received empirical antibiotic therapy before blood cultures were obtained (usually a second- or third-generation cephalosporin and aminoglycoside), the regimen was continued in the first 2 postoperative weeks and then changed to oral cephalosporins.

Microbiology
In 2 patients, blood cultures were positive for Staphylococcus aureus (see Table 1), which was resistant to methicillin in one of them. Coagulase-negative staphylococci were found in 2 patients and streptococci in 1. In another patient who had undergone repeated renal transplantation, Aspergillus fumigatus was demonstrated on the aortic valve. In 5 patients, bacterial cultures were negative because they were given empirical antibiotic therapy at the onset of fever before blood cultures had been obtained.

	Results

Top Abstract Introduction Patients and methods Results Comment References

 
Two patients died in the perioperative period. One of them was a 75-year-old woman who required operation for prosthetic valve endocarditis. In addition, she had received a triple bypass at the primary operation, and at reoperation, the right coronary artery graft was found to be occluded. After recurrent cardiac decompensation and severe pulmonary edema, she deteriorated rapidly at resternotomy and required urgent cannulation and institution of cardiopulmonary bypass. This patient was weaned from cardiopulmonary bypass with intraaortic balloon pump support. However, persistent low cardiac output state unresponsive to medical therapy led to multiorgan failure and death on the first postoperative day.

The second patient was a 49-year-old woman with three failed renal transplants, abdominal sepsis, and invasive pulmonary aspergillosis. She died from sepsis on postoperative day 5. Postmortem examination in the 2 patients showed no signs of suture dehiscence or undue intrapericardial hematoma secondary to aortic root replacement.

One 31-year-old male patient died 13 months after surgery in his sleep. After aortic root replacement, he had a dual-chamber pacemaker inserted for complete atrioventricular block and was well at follow-up examination 2 weeks before death. Postmortem examination was not performed.

Survival of the remaining patients is listed in Table 2. All surviving patients are currently well in NYHA classes I (5) or II (2), with no signs of valve dysfunction or recurrent intracardiac defects on clinical and transthoracic echocardiographic follow-up.

	Comment

Top Abstract Introduction Patients and methods Results Comment References

 
Due to the patients’ preoperative condition and persistent sepsis, surgical treatment of severe (ie, necrotizing, destructive endocarditis) is a technically demanding procedure with a reported mortality rate of 9% to 23% [6].Hemodynamic deterioration due to severe regurgitation, intracardiac fistulation, and the high risk of cerebral embolization usually call for urgent or emergency surgical intervention. Although complete resection of all infected and necrotic tissue allows for control of the local infection, it results in extensive defects.

Discussions about the optimum modality for reconstruction are still continuing. Because of their good results, some authors advocate reconstruction with autologous or bovine pericardium and insertion of a mechanical prosthesis in younger patients or a stented bioprosthesis in older ones [2–4], whereas others recommend the use of homografts, which in their experience, yield better results, provide technical advantages, and are more resistant to bacterial infection [5, 6, 8, 9] or even an autograft operation [5].

As a suitable homograft is often not available in such urgent cases, we decided to use xenografts because they are similar in terms of performance and surgical handling [10], and possibly also with respect to long-term results [11, 12]. On account of our good initial results, we now prefer the use of xenografts over homografts for this indication. The Freestyle aortic root bioprosthesis is a complete porcine aortic root with ligated coronary arteries, which is fixed in glutaraldehyde and treated with alpha-amino oleic acid to preclude calcification. It is less flexible and pliable than fresh or cryopreserved homografts, and little is known about its resistance to infection in active endocarditis. However, in a 5-year analysis of 95 patients, no reoperations for prosthetic valve endocarditis were necessary [3], and freedom from endocarditis was reported in 98% of patients at 5 years in a 21-center Food and Drug Administration clinical trial including 1,100 patients [13].

There were no significant technical problems resulting from a lack of pliability, and no major problems due to bleeding were encountered at the proximal or distal suture lines or at the reimplantation sites of the coronary ostia. Except for the initial cases autologous pericardium was employed to buttress the suture line at the anastomosis with the aorta to avoid bleeding from the suture tracts in the xenograft. None of our patients required reoperation; postmortem studies in 2 patients revealed no hematoma or other signs of technical problems. So far, the mortality rate in our series (20%) is in the expected range [4] and must be related to the extremely poor prognosis of the 2 patients who died in the perioperative period. Yet to date, no significant series of patients with other conduits has been reported in the literature where there has been freedom from reoperations for bleeding as well as freedom from recurrent endocarditis in all cases.

So far, only a few cases have been reported where the Freestyle bioprosthesis was used for endocarditis of comparable severity. In 3 patients with partial or complete discontinuity of the aortoventricular junction, a modified subcoronary implantation technique of the xenograft was described [14]. All patients survived with no signs of recurrent infection at 6 months of follow-up. Sakaguchi and associates [15] also used a subcoronary implantation technique in 1 patient with prosthetic valve endocarditis and abscess formation. Up to now, there has been a single report on full aortic root replacement using the Freestyle bioprosthesis for the same indication in 2 patients with favorable outcomes [16].

On account of the excellent surgical results in our series and the freedom from recurrent endocarditis in all survivors for up to 42 months postoperatively, we recommend the use of the Freestyle stentless bioprosthesis for this indication primarily in patients older than 60 years. In emergency settings and if a suitable homograft is not available, it seems to be a viable treatment option in younger patients as well.

	References

Top Abstract Introduction Patients and methods Results Comment References

 

1. David T.E. The surgical treatment of patients with prosthetic valve endocarditis. Semin Thorac Cardiovasc Surg 1995;7:47-53.[Medline]
2. d’Udekem Y., David T.E., Feindel C.M., Armstrong S., Sun Z. Long-term results of operation for paravalvular abscess. Ann Thorac Surg 1996;62:48-53.[Abstract/Free Full Text]
3. Aoyagi S., Fukunaga S., Tayama E., Hayashida N., Kawara T. Surgical treatment of prosthetic valve endocarditis with left ventricular-aortic discontinuity: reconstruction of the left ventricular outflow tract with a xenopericardial conduit. J Heart Valve Dis 2001;10:367-370.[Medline]
4. Aagaard J., Andersen P.V. Acute endocarditis treated with radical debridement and implantation of mechanical or stented bioprosthetic devices. Ann Thorac Surg 2001;71:100-103.[Abstract/Free Full Text]
5. Niwaya K., Knott-Craig C.J., Santangelo K., Lane M.M., Chandrasekaran K., Elkins R.C. Advantage of autograft and homograft valve replacement for complex aortic valve endocarditis. Ann Thorac Surg 1999;67:1603-1608.[Abstract/Free Full Text]
6. Knosalla C., Weng Y., Yankah A.C., et al. Surgical treatment of active infective aortic valve endocarditis with associated periannular abscess: 11 year results. Eur Heart J 2000;21:490-497.[Abstract/Free Full Text]
7. Joyce F., Tingleff J., Aagaard J., Pettersson G. The Ross operation in the treatment of native and prosthetic aortic valve endocarditis. J Heart Valve Dis 1994;3:371-376.[Medline]
8. Haydock D., Barratt-Boyes B., Macedo T., Kirklin J.W., Blackstone E. Aortic valve replacement for active infectious endocarditis in 108 patients: a comparison of freehand allograft valves with mechanical prostheses and bioprostheses. J Thorac Cardiovasc Surg 1992;103:130-139.[Abstract]
9. Pagano D., Allen S.M., Bonser R.S. Homograft aortic valve and root replacement for severe destructive native or prosthetic endocarditis. Eur J Cardiothorac Surg 1994;8:173-176.[Abstract]
10. Kon N.D., Cordell A.R., Adair S.M., Kitzman D.W. Comparison of results using "freestyle" stentless porcine aortic root bioprosthesis with cryopreserved aortic allograft. Semin Thorac Cardiovasc Surg 1999;11:69-73.[Medline]
11. Melina G., Rubens M.B., Birks E.J., Bizzarri F., Khaghani A., Yacoub M.H. A quantitative study of calcium deposition in the aortic wall following Medtronic Freestyle compared with homograft aortic root replacement: a prospective randomized trial. J Heart Valve Dis 2000;9:97-103.[Medline]
12. Melina G., Rubens M.B., Amrani M., Khaghani A., Yacoub M.H. Electron beam tomography for cusp calcification in homograft versus Freestyle xenografts. Ann Thorac Surg 2001;7:S368-370.
13. Doty D.B., Cafferty A., Cartier P., et al. Aortic valve replacement with Medtronic Freestyle bioprosthesis: 5-year results. Semin Thorac Cardiovasc Surg 1999;11:35-41.[Medline]
14. Katsumata T., Vaccari G., Westaby S. Stentless xenograft repair of excavating aortic root sepsis. J Card Surg 1998;13:440-444.[Medline]
15. Sakaguchi T., Sawa Y., Ohtake S., Hirata N., Matsuda H. The Freestyle stentless bioprosthesis for prosthetic valve endocarditis. Ann Thorac Surg 1999;67:533-535.[Abstract/Free Full Text]
16. Fujii H., Suehiro S., Shibata T., et al. Successful aortic root replacement for prosthetic valve endocarditis using the freestyle stentless bioprosthesis: report of two cases. Kyobu Geka 2000;53:323-327.[Medline]

This article has been cited by other articles:

				A. John, B. Al-Hariri, J. Ackemann, M. El-Mehsen, S. Roethemeyer, and H. Warnecke Subcoronary Implantation of a Stentless Valve in Patients with Aortic Aneurysms Asian Cardiovasc Thorac Ann, October 1, 2008; 16(5): 355 - 360. [Abstract] [Full Text] [PDF]

				K. Okada, H. Tanaka, H. Takahashi, N. Morimoto, H. Munakata, M. Asano, M. Matsumori, Y. Kawanishi, K. Nakagiri, and Y. Okita Aortic Root Replacement for Destructive Aortic Valve Endocarditis with Left Ventricular-Aortic Discontinuity Ann. Thorac. Surg., March 1, 2008; 85(3): 940 - 945. [Abstract] [Full Text] [PDF]

				W. Ngatchou, C. Stefanidis, A. S.E. Ramadan, and D. De Canniere Recurrent endocarditis of a bicuspid aortic valve due to Q fever Interactive CardioVascular and Thoracic Surgery, December 1, 2007; 6(6): 815 - 817. [Abstract] [Full Text] [PDF]

				B. Mahesh, G. Angelini, M. Caputo, X. Y. Jin, and A. Bryan Prosthetic Valve Endocarditis Ann. Thorac. Surg., September 1, 2005; 80(3): 1151 - 1158. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Johannes O. Bonatti Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Müller, L. C. Articles by Laufer, G. Search for Related Content PubMed PubMed Citation Articles by Müller, L. C. Articles by Laufer, G. Related Collections Valve disease