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Aortic Root Replacement for Destructive Aortic Valve Endocarditis with Left Ventricular–Aortic Discontinuity
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Aortic Root Replacement for Destructive Aortic Valve Endocarditis with Left Ventricular–Aortic Discontinuity Kenji Okada, MD, PhD, Hiroshi Tanaka, MD, PhD, Hideki Takahashi, MD, Naoto Morimoto, MD, Hiroshi Munakata, MD, Mitsuru Asano, MD, PhD, Masamichi Matsumori, MD, PhD, Yujiro Kawanishi, MD, PhD, Keitaro Nakagiri, MD, PhD, and Yutaka Okita, MD, PhD Department of Surgery, Division of Cardiovascular Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
Background. Destructive aortic valve endocarditis causes the development of left ventricular–aortic discontinuity. Our experience of aortic root replacement in patients with the left ventricular–aortic discontinuity is presented. Methods. Between 1999 and 2006, 8 patients (7 men, 1 woman) with left ventricular–aortic discontinuity underwent aortic root replacement in our institute. Their mean age was 56 years. Six patients were in New York Heart Association functional class III or higher. Four patients were diagnosed to have native valve endocarditis, and 4 had prosthetic valve endocarditis (previous aortic valve replacements in 2 patients, aortic root replacements in 2). Radical débridement of the aortic root abscess was performed in all patients, followed by reconstruction of the aortic annulus using autologous or xenogenic pericardium in 2 patients. Fibrin glue saturated with antibiotics
was applied into the cavity in 5 patients. Aortic root replacement was achieved with pulmonary autograft (Ross procedure) in 4 patients and stentless aortic root xenograft in 3. One patient who had advanced liver cirrhosis underwent aortic valve replacement with a stentless xenograft by subcoronary fashion. Results. No patients died during hospitalization or follow-up. Freedom from major adverse cardiac events was noted in 67% of the patients at 5 years. Conclusions. An excellent outcome can be achieved by radical exclusion of abscess in the cavity, followed by root replacement with viable pulmonary autograft or flexible stentless aortic root xenograft in patients with left ventricular–aortic discontinuity.
B
Patients and Methods
ecause surgical treatment for heart valve diseases is complicated by annular abscess, which is likely to increase perioperative morbidity, the selection of the surgical strategy requires special attention. Severely injured heart valves with native valve endocarditis (NVE) or prosthetic valve endocarditis (PVE) destroy adjacent tissues beyond the valve annulus, resulting in devastating aortic root abscess [1–3]. The pathology sometimes induces the catastrophic complication of left ventricular– aortic (LV-Ao) discontinuity [4], and the treatment is quite demanding in most cases. The objective of this study is to report our surgical strategies and outcome of aortic root replacement (ARR) for the destroyed aortic root with LV-Ao discontinuity.
(Ann Thorac Surg 2008;85:940 –5) © 2008 by The Society of Thoracic Surgeons
Patients This study was approved by the Kobe University Graduate School of Medicine Institutional Review Board, and the need for individual consent was waived. From October 1999 to August 2006, 97 ARRs were done in our institute. Nine patients (9.3%) had LV-Ao discontinuity, and 8 of them with destructive aortic valve infective endocarditis (IE) were involved in the current study. Patient profiles are summarized in Table 1. There were four NVE and four PVE in 8 infective endocarditis patients. The average age was 56.0 ⫾ 12.8 (range, 32 to 69 years), and 7 patients were men.
Native Valve Endocarditis
Accepted for publication Oct 26, 2007. Address correspondence to Dr Okada, Department of Surgery, Division of Cardiovascular Surgery, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan; e-mail: [email protected].
© 2008 by The Society of Thoracic Surgeons Published by Elsevier Inc
The 4 patients with NVE had active aortic valve endocarditis with accompanying aortic root destruction due to abscess formation. Native aortic valves were all bicuspid, and the function of the aortic valve was aortic regurgitation in 3 patients and stenosis in 1. In 2 patients (patients 3 and 4), the organisms were identified as Streptococcus spp. Two patients (patients 1 and 3) had a comorbidity of preoperative stroke due to thromboembolism. Two pa0003-4975/08/$34.00 doi:10.1016/j.athoracsur.2007.10.088
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Table 1. Patient Profiles and Operative Urgency Etiology No
Sex
Age
1 2 3 4 5 6 7 8
M M M M M F M M
67 50 45 32 66 60 59 69
a
No vegetation.
⫹ ⫽ yes;
Vegetation Size (mm) NVE (active) 30 NVE (active) 15 NVE (active) 15 NVE (active) 20 PVE (active)a PVE (active)a PVE (active)a PVE (active) a
⫻ ⫻ ⫻ ⫻
Microorganism 20 20 15 20
Unknown Unknown Streptococcus spp Streptococcus spp Streptococcus MRSA MRSA Strep agalactiae
Valvular Disease AR (BAV) AS (BAV) AR (BAV) AR (BAV) Paravalvular Paravalvular Paravalvular Paravalvular
leakage leakage leakage leakage
NYHA
CHF
Shock
Stroke
Urgency
II III III III III III III II
⫺ ⫺ ⫹ ⫹ ⫹ ⫺ ⫺ ⫺
⫹ ⫺ ⫺ ⫺ ⫺ ⫺ ⫺ ⫺
⫹ ⫺ ⫹ ⫺ ⫺ ⫺ ⫺ ⫺
Emergency Emergency Urgent Urgent Emergency Urgent Urgent Urgent
⫺ ⫽ no.
AR ⫽ aortic regurgitation; AS ⫽ aortic stenosis, BAV ⫽ bicuspid aortic valve; CHF ⫽ congestive heart failure; Staphylococcus aureus; NVE ⫽ native valve endocarditis; PVE ⫽ prosthetic valve endocarditis.
tients had preoperative intractable congestive heart failure (patients 3 and 4), and 1 patient had septic shock (patient 1). Two patients underwent surgery on emergency basis (patients 1, 2). One was in New York Heart Association (NYHA) functional class II and 3 were in class III. All patients had annular abscess of the left coronary cusp, which extended further and resulted in LV-Ao discontinuity. The severity of LV-Ao discontinuity was expressed as the central angle of LV-Ao discontinuity in the entire circle, which averaged 165° (range: 90° to 270°) in NVE cases (Table 2). In patient 3, additional aorta– right ventricle fistula was formed thorough the sinus of Valsalva at the noncoronary cusp.
Prosthetic Valve Endocarditis All patients had active prosthetic infective endocarditis in an aortic position accompanied with paravalvular leakage. The organism was methicillin-resistant Staphylococcus aureus (MRSA) in 2 patients. Patient 5 had intractable congestive heart failure and underwent an emergency operation. One patient was in NYHA class II, and 3 were in class III (Table 1). In 3 patients, aortic valve replacement (AVR) had been previously performed with mechanical valves (Omniscience 23A; Medical CV Inc, Inner Grove Heights, MN; SJM 25A, St. Jude Medical, St. Paul, MN) or tissue valve (Perimount 23A, Edwards Lifesciences, Irvine, CA). Bentall procedure had been done in patient 6 with a SJM 25A. Patient 7 had a history of AVR with SJM 25A, followed by aortic root replacement (Cabrol coronary reconstruction) plus ascending aortic replacement preserving the mechanical valve for progressive dilatation of the ascending aorta. All patients in this group had more severely destroyed annulus of more than half circumference of the aortic annulus. The central angle of the LV-Ao discontinuity in the entire circumference was 202° (range, 180° to 270°) in the PVE cases (Table 2). Patient 6 also had a fistula between the left ventricle and the left atrium. In patient 7,
MRSA ⫽ methicillin-resistant
the echocardiogram clearly demonstrated an abscess cavity in which the central angle of the discontinuity was as wide as 270° and was extended posteriorly to the left atrium with a pseudoaneurysm formation, although the anterior part of mitral annulus was preserved (Fig 1). Patients 6 and 7, who had had undergone previous replacement of the ascending aorta, also had prosthetic graft infection.
Surgical Strategy Our surgical strategy was: 1. Complete removal of infective or necrotic tissue (radical débridement) and drainage of abscess cavity was primary indispensable. 2. Annular reconstruction was applied using autologous (primary case) or xenogenic pericardium (redo case), if necessary. Fibrin glue saturated with antibiotics was injected into the cavity. The fistula was closed by pericardium as well. 3. Pulmonary autograft (Ross procedure) had the first priority and stentless tissue valve had second for the ARR because of the better adaptation to the tissue. However, pulmonary autograft was not used in the patients with Marfan disease (patient 6) or annuloaortic ectasia (patient 7). The details of surgical procedures are summarized in Table 2. Annular reconstruction was performed in 2 patients (patients 1 and 8), and closure of fistula was done in 2 patients (patients 3 and 6) using autologous in 2 patients and xenogenic pericardium in 2 (Xenomedica, 1; Edwards Lifesciences, Irvine, CA; Periguard, 1; BioVascular, Inc, St. Paul, MN). To perform ARR with autograft or stentless full root, we reconstructed a neoannulus with the xenogenic or autologous pericardium using 4 – 0 Prolene (Ethicon, Somerville, NJ) onto the destructed annulus, followed by ARR. Fibrin glue saturated with antibiotics (amikacin sulfate, 2; tobramycin, 1; imipenem/cilastatin sodium, 1) was applied in 5 patients. The grafts for ARR consisted of
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MAP ⫽ mitral LV ⫽ left ventricle; AVR ⫽ aortic valve replacement; LA ⫽ left atrium; LCC ⫽ left coronary cusp; LMT ⫽ left main trunk; RCA ⫽ right coronary artery; RCC ⫽ right coronary cusp; RV ⫽ right ventricle. ARR ⫽ aortic root replacement; NCC ⫽ non coronary cusp; Ao ⫽ aorta; annuloplasty;
Xenogenic annular reconstruction AVR (Freestyle 23 Subcoronary) LCC-RCC NCC-RCC (180°) 8
1) AVR (SJM25) 2) Cabrol AVR (CEP23) 7
ARR (Prima Plus 25)
— AVR Omniscience 23 Bentall (SJM25) 4 5 6
Ross Ross — — 2 3
LCC, RCC (180°) LCC, RCC (270°) Ao-RV fistula LCC, RCC (90°) RCC, NCC (180°) LCC (180°); LV-LA fistula graft infection LCC (270°) graft infection
Ross Ross failure, ARR (Freestyle 27) ARR (Freestyle 25)
Amikacin sulfate
— — Imipenem, cilastatin sodium Amikacin sulfate — —
Omentum; rifampicin-soaked graft; CABG (LMT, RCA) —
Tobramycin Tobramycin — —
CABG, RCA
— —
Autologous annular reconstruction — Autologous Ao-RV fistula closure — — Xenogenic LV-LA fistula closure — Ross LCC (120°) — 1
No
Previous operation
LV-Ao Discontinuity Site (degree)
Operation
Patch Plasty
Topical Antibiotics
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Others
OKADA ET AL LV-AORTIC DISCONTINUITY
Table 2. Previous Operative Modes and Details of Left Ventricular-Aortic Discontinuity and Surgical Repair
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pulmonary autografts in 4 patients and stentless porcine valve in 4 (Freestyle, Medtronic Inc in 3; Prima Plus, Edwards Lifesciences in 1). One stentless porcine valve was selected after the failure of Ross procedure (patient 5). In patient 7, who had a MRSA-contaminated prosthetic aortic graft, a rifampicin-soaked graft (Gelsoft 20 mm; Vascutek Ltd, Renfrewshire, Scotland) was implanted, covered by the greater omentum. In patients 6 and 7, who had destroyed coronary ostia, coronary artery bypass grafting (CABG) was also performed. Saphenous vein grafts were placed on the right coronary artery in patient 6 and on the left main trunk and the left coronary artery in patient 7.
Statistical Analysis The data are expressed as mean ⫾ standard deviation. The freedom from cardiac events was assessed by the KaplanMeier method using SPSS software (SPSS Inc, Chicago, IL).
Results Early Results No hospital death was observed. Cardiopulmonary bypass time was 378.9 ⫾ 119.4 minutes, myocardial ischemic time was 249.5 ⫾ 53.2 minutes, and the intraoperative transfusion requirement was 36.0 ⫾ 46.0 U. Postoperative profiles of the patents are summarized in Table 3. Postoperative intensive care unit stay was 4.2 ⫾ 4.5 days, and hospitalization was 56.6 ⫾ 9.1 days. Morbidity included complete A-V block in patient 3 (transient). Patient 5 had low output syndrome and atrial fibrillation, and required mediastinal reexploration for bleeding and prolonged respiratory support. Patient 8 had liver cirrhosis in Child-Pugh class B had postoperative massive ascites.
Mid-Term Results Average follow-up was 38.3 ⫾ 28.6 months (range, 4 to 78 months). No late death was observed. Patient 2, who had undergone a Ross procedure, had valve sparing (neoaortic valve) root replacement 3 years after the first operation because of pulmonary autograft dilatation with severe valve regurgitation; this was followed by AVR after 1 month owing to valve insufficiency with fenestration of the preserved neoaortic valve. Freedom from major adverse cardiac events was 100% at 3 years and 66.7% at 5 years after operation (Fig 2). No recurrent infection was observed during the follow-up.
Comment Because surgical treatment for heart valve diseases is complicated by infection, which is likely to result in increased morbidity and mortality, the selection of the surgical strategy requires careful attention. Severe NVE or PVE often destroys the annulus and results in the formation of an aortic root abscess. The operative mortality rate is still disappointing, with reports 9.4% to 32% [1–3], and freedom from reoperation is as low as 45%, particularly with PVE cases at 1 year after operation [5].
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Fig 1. (A) Preoperative echocardiogram in patient 7. The asterisk (*) clearly indicates the part of left ventricle (LV)–ascending aorta (Ao) discontinuity. The large abscess cavity was extended back adjacent to the left atrium with pseudoaneurysm formation. The arrow points to the St. Jude Medical (SJM) valve. (LA ⫽ left atrium). (B) Intraoperative findings of the aortic root from the surgeon’s view. (C). Schema for the intraoperative photo. A cannula for selective coronary perfusion was inserted into each coronary artery. Dotted line circled the extent of pseudoaneurysm. (CP ⫽ cardioplegia; LCA ⫽ ostium of left coronary artery; MV ⫽ mitral valve; RCA ⫽ ostium of right coronary artery.)
In the literature, aortic root abscess secondary to infective endocarditis is one of the major causes of LV-Ao discontinuity [4], which penetrates into the adjacent structures such as the right/left atriums and ventricles. A greater part of circumference of the annulus loses its connection with the left ventricle, sometimes just leaving the aortomitral continuity. Surgical outcome for advanced active infective endocarditis has not been satisfactory, particularly in PVE patients who require ARR. Leyh and colleagues [6] reported the excellent long-term results of the ARR in patients with prosthetic active PVE regardless of the graft materials; however, the hospital mortality rate was still high as high as 18.5% [6]. Although our experience comprised a limited number of patients, no hospital or mid-term death occurred in this series. Because a delay in operation on the aortic root frequently causes a fatal complication, proper judgment for the timing of the operation is mandatory. Delahaye and
colleagues [7] pointed that the timing of the surgical intervention for infective endocarditis tended to be delayed despite guidelines on the surgical management for infective endocarditis. The longer the delay, the greater destruction of the aortic root and the more complicated the surgical procedure becomes. The advanced annular lesion, such as the LV-Ao discontinuity, was observed in as many as 9 patients (9.3%) of all ARRs, and 8 of them with destructive aortic valve endocarditis were involved in the current study in our institute. Seven patients (78%) were in NYHA class III or higher, 4 patients (44%) were in the status of intractable congestive heart failure, and 1 was in septic shock. Advanced annular abscess sometimes causes intracardiac fistulas, such as to the left ventricular outflow tract and the right/left atriums [8], as occurred in our patients 3 and 6. As Leyh and colleagues [6] recommended, aggressive, radical débridement is indispensable for the success of
Table 3. Postoperative Patient Profiles Duration of Inotrope Support
Respiratory Support
ICU stay, days
Hospital stay, days
Post-op antibiotics
Complications
1 2
29 hours 96 hours
7 hours 24 hours
2 3
47 65
VCM, AMK, PAPM/BP VCM, AMK
3
48 hours
7 hours
4
62
PCG, AMK
4 5
11 hours 52 days
2 hours 60 days
1 15
53 67
SBTPC, AMK FMOX, AMK
6 7 8
4 days 12 hours 4 hours
10 hours 14 hours 35 hours
3 3 2
49 65 45
VCM, AMK, IPM/CS VCM, AMK SBTPC, AMK
AF Drug-induced hepatitis Transient A-V block Liver dysfunction Bleeding, LOS, AF, prolonged respiratory support AF — Ascites, prolonged respiratory support
No
AF ⫽ atrial fibrillation; AMK ⫽ amikacin sulfate; syndrome; PAPM/BP ⫽ panipenem/betamipron; hydrochloride.
FMOX ⫽ flomoxef sodium; IPM/CS ⫽ imipenem/cilastatin sodium; LOS ⫽ low output PCG ⫽ penicillin potassium; SBTPC ⫽ sultamicillin tosylate; VCM ⫽ vancomycin
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OKADA ET AL LV-AORTIC DISCONTINUITY
Fig 2. Freedom from major adverse cardiac event. Cardiac event-free rates at 3 and 5 years after operations were 100% and 66.7%, respectively.
treatment of aortic root abscess; however, the débridement sometimes produces excessive annular tissue defect. Reconstruction of destroyed annulus by autologous or xenogenic pericardium is required to secure the pulmonary autograft, allograft, or stentless tissue valve. Two patients in the present series required annular reconstruction with autologous or xenogenic pericardium. When ARR is required because of infective endocarditis in native or prosthetic valves, allograft has been recommended as the valve of choice rather than mechanical or bioprosthetic valves [9], and is particularly useful in patients with PVE complicated by abscess or paravalvular leakage, or both [10]. Others have reported that excellent long-term results could be achieved regardless of the material used for ARR in patients with PVE [6, 11]. In the current study, ARR was primarily applied in all cases except in 1 patient, who had advanced liver cirrhosis (Child type B) with thrombocytopenia and required a less-invasive surgical mode. Considerations for the ideal graft conduit for the patients with LV-Ao discontinuity are: 1. The conduit is viable tissue, which is expected to be effective against bacterial infection. 2. It should have mechanically better fitting property towards irregular annular plane after the complete débridement. 3. A constant and prompt supply of the grafts is guaranteed for emergency cases. Published reports indicate allograft has been the ideal material for ARR [9, 12]; however, it is difficult to obtain the graft with requested size, particularly for urgent or emergency cases. For the reconstruction of the destroyed aortic root, prosthetic composite graft, pulmonary autograft, or stentless tissue valve are one of the practical alternatives. Prosthetic composite graft has superiority in terms of availability, and Leyh and colleagues [6] have reported that excellent long-term results could be
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achieved regardless of the material used for ARR in patients with PVE. In our opinion, however, some difficulties occur with prosthetic composite grafts in obtaining complete tissue adaptation for the destroyed annulus. Residual dead space may cause recurrent infection during follow-up. The Ross procedure using the root replacement technique has been reported to demonstrate excellent longterm survival and low thromboembolic and endocarditis risk [13]. This procedure is an excellent therapeutic option for active aortic valve endocarditis, with low morbidity and mortality including a very low recurrence rate of endocarditis [14 –17]. Because pulmonary autograft is viable tissue, it is more resistant to infection and is suitable for the irregular ARR after aggressive débridement. However, the Ross procedure has potential risk of the necessity for reconstruction of the right ventricular outflow tract (RVOT). A stentless tissue valve was selected for the reconstruction in 4 patients, who had no calcification or stenosis during a follow-up of 53 months.. So far, we have not experienced any problem in the RVOT, but further investigation should be determined. Patients with Marfan syndrome (patient 6) or annuloaortic ectasia (patient 7) were excluded from Ross procedure because of possible future annular dilatation. Although it remains unclear whether the stentless tissue valve is resistant to infection, it could be a first alternative to pulmonary autograft or allograft in the treatment of severe destructive aortic root disease [18 –20]. Topical application of antibiotics still remains controversial. Several reports on the efficacy of the topical use of antibiotics in vitro and in vivo concluded that pretreatment of prosthetic Dacron (DuPont, Wilmington, DE) grafts with antibiotic/fibrin compound resulted in binding of a sufficient amount of antibiotics for at least 1 week [6, 21, 22]. We applied fibrin glue saturated with antibiotics into the cavity, and there was no recurrent infection; however, efficacy of topical application was unclear. The number of patients is too small to elucidate the important factors that contributed to the excellent outcome, and the follow-up was not long enough to conclude lack of complications in long-term follow-up. The efficacy of topical application of antibiotics on the prevention of recurrent infection was entirely unclear, although some articles have supported the hypothesis. Furthermore, the severity of the infection and the causative microorganism might vary among patients. In conclusion, excellent outcome during short- and mid-term follow-up can be achieved by radical exclusion of abscess cavity, followed by root replacement with a viable pulmonary autograft (Ross procedure) or stentless aortic root xenograft in patients with LV-Ao discontinuity caused by destructive endocarditis.
References 1. Glazier JJ, Verwilghen J, Donaldson RM, Ross DN. Treatment of complicated prosthetic aortic valve endocarditis with annular abscess formation by homograft aortic root replacement. J Am Coll Cardiol 1991;17:1177– 82.
2. Moon MR, Miller DC, Moore KA, et al. Treatment of endocarditis with valve replacement: the question of tissue versus mechanical prosthesis. Ann Thorac Surg 2001;71:1164 –71. 3. Watanabe G, Haverich A, Speier R, Dresler C, Borst HG. Surgical treatment of active infective endocarditis with paravalvular involvement. J Thorac Cardiovasc Surg 1994;107: 171–7. 4. Symbas PN, Vlasis SE, Zacharopoulos L, Lutz JF. Aortic-left ventricular discontinuity and aortic regurgitation from acute endocarditis. South Med J 1982;75:1476 – 8. 5. Delay D, Pellerin M, Carrier M, et al. Immediate and long-term results of valve replacement for native and prosthetic valve endocarditis. Ann Thorac Surg 2000;70:1219 –23. 6. Leyh RG, Knobloch K, Hagl C, et al. Replacement of the aortic root for acute prosthetic valve endocarditis: prosthetic composite versus aortic allograft root replacement. J Thorac Cardiovasc Surg 2004;127:1416 –20. 7. Delahaye F, Rial MO, de Gevigney G, Ecochard R, Delaye J. A critical appraisal of the quality of the management of infective endocarditis. J Am Coll Cardiol 1999;33:788 –93. 8. Bozbuga N, Erentug V, Erdogan HB, et al. Surgical treatment of aortic abscess and fistula. Tex Heart Inst J 2004;31:382– 6. 9. Haydock D, Barratt-Boyes B, Macedo T, Kirklin JW, 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 –9. 10. Lopes S, Calvinho P, de Oliveira F, Antunes M. Allograft aortic root replacement in complex prosthetic endocarditis. Eur J Cardiothorac Surg 2007;32:126 –30. 11. Hagl C, Galla JD, Lansman SL, et al. Replacing the ascending aorta and aortic valve for acute prosthetic valve endocarditis: is using prosthetic material contraindicated? Ann Thorac Surg 2002;74:S1781–5. 12. Sabik JF, Lytle BW, Blackstone EH, Marullo AG, Pettersson GB, Cosgrove DM. Aortic root replacement with cryopre-
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14. 15. 16. 17. 18. 19.
20. 21. 22.
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served allograft for prosthetic valve endocarditis. Ann Thorac Surg 2002;74:650 –9. Kouchoukos NT, Masetti P, Nickerson NJ, Castner CF, Shannon WD, Davila-Roman VG. The Ross procedure: longterm clinical and echocardiographic follow-up. Ann Thorac Surg 2004;78:773– 81. Birk E, Sharoni E, Dagan O, et al. The Ross procedure as the surgical treatment of active aortic valve endocarditis. J Heart Valve Dis 2004;13:73–7. Joyce F, Tingleff J, Pettersson G. The Ross operation: results of early experience including treatment for endocarditis. Eur J Cardiothorac Surg 1995;9:384 –91. Pettersson G, Tingleff J, Joyce FS. Treatment of aortic valve endocarditis with the Ross operation. Eur J Cardiothorac Surg 1998;13:678 – 84. Schmidtke C, Dahmen G, Sievers HH. Subcoronary Ross procedure in patients with active endocarditis. Ann Thorac Surg 2007;83:36 –9. Katsumata T, Vaccari G, Westaby S. Stentless xenograft repair of excavating aortic root sepsis. J Card Surg 1998;13: 440 – 4. Muller LC, Chevtchik O, Bonatti JO, Muller S, Fille M, Laufer G. Treatment of destructive aortic valve endocarditis with the Freestyle Aortic Root Bioprosthesis. Ann Thorac Surg 2003;75:453– 6. Sakaguchi T, Sawa Y, Ohtake S, Hirata N, Matsuda H. The Freestyle stentless bioprosthesis for prosthetic valve endocarditis. Ann Thorac Surg 1999;67:533–5. Haverich A, Hirt S, Karck M, Siclari F, Wahlig H. Prevention of graft infection by bonding of gentamycin to Dacron prostheses. J Vasc Surg 1992;15:187–93. Karck M, Siclari F, Wahlig H, Sperling U, Schmid C, Haverich A. Pretreatment of prosthetic valve sewing-ring with the antibiotic/fibrin sealant compound as a prophylactic tool against prosthetic valve endocarditis. Eur J Cardiothorac Surg 1990;4:142– 6.
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Aortic Root Replacement for Destructive Aortic Valve Endocarditis with Left Ventricular–Aortic Discontinuity Kenji Okada, MD, PhD, Hiroshi Tanaka, MD, PhD, Hideki Takahashi, MD, Naoto Morimoto, MD, Hiroshi Munakata, MD, Mitsuru Asano, MD, PhD, Masamichi Matsumori, MD, PhD, Yujiro Kawanishi, MD, PhD, Keitaro Nakagiri, MD, PhD, and Yutaka Okita, MD, PhD Department of Surgery, Division of Cardiovascular Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
Background. Destructive aortic valve endocarditis causes the development of left ventricular–aortic discontinuity. Our experience of aortic root replacement in patients with the left ventricular–aortic discontinuity is presented. Methods. Between 1999 and 2006, 8 patients (7 men, 1 woman) with left ventricular–aortic discontinuity underwent aortic root replacement in our institute. Their mean age was 56 years. Six patients were in New York Heart Association functional class III or higher. Four patients were diagnosed to have native valve endocarditis, and 4 had prosthetic valve endocarditis (previous aortic valve replacements in 2 patients, aortic root replacements in 2). Radical débridement of the aortic root abscess was performed in all patients, followed by reconstruction of the aortic annulus using autologous or xenogenic pericardium in 2 patients. Fibrin glue saturated with antibiotics
was applied into the cavity in 5 patients. Aortic root replacement was achieved with pulmonary autograft (Ross procedure) in 4 patients and stentless aortic root xenograft in 3. One patient who had advanced liver cirrhosis underwent aortic valve replacement with a stentless xenograft by subcoronary fashion. Results. No patients died during hospitalization or follow-up. Freedom from major adverse cardiac events was noted in 67% of the patients at 5 years. Conclusions. An excellent outcome can be achieved by radical exclusion of abscess in the cavity, followed by root replacement with viable pulmonary autograft or flexible stentless aortic root xenograft in patients with left ventricular–aortic discontinuity.
B
Patients and Methods
ecause surgical treatment for heart valve diseases is complicated by annular abscess, which is likely to increase perioperative morbidity, the selection of the surgical strategy requires special attention. Severely injured heart valves with native valve endocarditis (NVE) or prosthetic valve endocarditis (PVE) destroy adjacent tissues beyond the valve annulus, resulting in devastating aortic root abscess [1–3]. The pathology sometimes induces the catastrophic complication of left ventricular– aortic (LV-Ao) discontinuity [4], and the treatment is quite demanding in most cases. The objective of this study is to report our surgical strategies and outcome of aortic root replacement (ARR) for the destroyed aortic root with LV-Ao discontinuity.
(Ann Thorac Surg 2008;85:940 –5) © 2008 by The Society of Thoracic Surgeons
Patients This study was approved by the Kobe University Graduate School of Medicine Institutional Review Board, and the need for individual consent was waived. From October 1999 to August 2006, 97 ARRs were done in our institute. Nine patients (9.3%) had LV-Ao discontinuity, and 8 of them with destructive aortic valve infective endocarditis (IE) were involved in the current study. Patient profiles are summarized in Table 1. There were four NVE and four PVE in 8 infective endocarditis patients. The average age was 56.0 ⫾ 12.8 (range, 32 to 69 years), and 7 patients were men.
Native Valve Endocarditis
Accepted for publication Oct 26, 2007. Address correspondence to Dr Okada, Department of Surgery, Division of Cardiovascular Surgery, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan; e-mail: [email protected].
© 2008 by The Society of Thoracic Surgeons Published by Elsevier Inc
The 4 patients with NVE had active aortic valve endocarditis with accompanying aortic root destruction due to abscess formation. Native aortic valves were all bicuspid, and the function of the aortic valve was aortic regurgitation in 3 patients and stenosis in 1. In 2 patients (patients 3 and 4), the organisms were identified as Streptococcus spp. Two patients (patients 1 and 3) had a comorbidity of preoperative stroke due to thromboembolism. Two pa0003-4975/08/$34.00 doi:10.1016/j.athoracsur.2007.10.088
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Table 1. Patient Profiles and Operative Urgency Etiology No
Sex
Age
1 2 3 4 5 6 7 8
M M M M M F M M
67 50 45 32 66 60 59 69
a
No vegetation.
⫹ ⫽ yes;
Vegetation Size (mm) NVE (active) 30 NVE (active) 15 NVE (active) 15 NVE (active) 20 PVE (active)a PVE (active)a PVE (active)a PVE (active) a
⫻ ⫻ ⫻ ⫻
Microorganism 20 20 15 20
Unknown Unknown Streptococcus spp Streptococcus spp Streptococcus MRSA MRSA Strep agalactiae
Valvular Disease AR (BAV) AS (BAV) AR (BAV) AR (BAV) Paravalvular Paravalvular Paravalvular Paravalvular
leakage leakage leakage leakage
NYHA
CHF
Shock
Stroke
Urgency
II III III III III III III II
⫺ ⫺ ⫹ ⫹ ⫹ ⫺ ⫺ ⫺
⫹ ⫺ ⫺ ⫺ ⫺ ⫺ ⫺ ⫺
⫹ ⫺ ⫹ ⫺ ⫺ ⫺ ⫺ ⫺
Emergency Emergency Urgent Urgent Emergency Urgent Urgent Urgent
⫺ ⫽ no.
AR ⫽ aortic regurgitation; AS ⫽ aortic stenosis, BAV ⫽ bicuspid aortic valve; CHF ⫽ congestive heart failure; Staphylococcus aureus; NVE ⫽ native valve endocarditis; PVE ⫽ prosthetic valve endocarditis.
tients had preoperative intractable congestive heart failure (patients 3 and 4), and 1 patient had septic shock (patient 1). Two patients underwent surgery on emergency basis (patients 1, 2). One was in New York Heart Association (NYHA) functional class II and 3 were in class III. All patients had annular abscess of the left coronary cusp, which extended further and resulted in LV-Ao discontinuity. The severity of LV-Ao discontinuity was expressed as the central angle of LV-Ao discontinuity in the entire circle, which averaged 165° (range: 90° to 270°) in NVE cases (Table 2). In patient 3, additional aorta– right ventricle fistula was formed thorough the sinus of Valsalva at the noncoronary cusp.
Prosthetic Valve Endocarditis All patients had active prosthetic infective endocarditis in an aortic position accompanied with paravalvular leakage. The organism was methicillin-resistant Staphylococcus aureus (MRSA) in 2 patients. Patient 5 had intractable congestive heart failure and underwent an emergency operation. One patient was in NYHA class II, and 3 were in class III (Table 1). In 3 patients, aortic valve replacement (AVR) had been previously performed with mechanical valves (Omniscience 23A; Medical CV Inc, Inner Grove Heights, MN; SJM 25A, St. Jude Medical, St. Paul, MN) or tissue valve (Perimount 23A, Edwards Lifesciences, Irvine, CA). Bentall procedure had been done in patient 6 with a SJM 25A. Patient 7 had a history of AVR with SJM 25A, followed by aortic root replacement (Cabrol coronary reconstruction) plus ascending aortic replacement preserving the mechanical valve for progressive dilatation of the ascending aorta. All patients in this group had more severely destroyed annulus of more than half circumference of the aortic annulus. The central angle of the LV-Ao discontinuity in the entire circumference was 202° (range, 180° to 270°) in the PVE cases (Table 2). Patient 6 also had a fistula between the left ventricle and the left atrium. In patient 7,
MRSA ⫽ methicillin-resistant
the echocardiogram clearly demonstrated an abscess cavity in which the central angle of the discontinuity was as wide as 270° and was extended posteriorly to the left atrium with a pseudoaneurysm formation, although the anterior part of mitral annulus was preserved (Fig 1). Patients 6 and 7, who had had undergone previous replacement of the ascending aorta, also had prosthetic graft infection.
Surgical Strategy Our surgical strategy was: 1. Complete removal of infective or necrotic tissue (radical débridement) and drainage of abscess cavity was primary indispensable. 2. Annular reconstruction was applied using autologous (primary case) or xenogenic pericardium (redo case), if necessary. Fibrin glue saturated with antibiotics was injected into the cavity. The fistula was closed by pericardium as well. 3. Pulmonary autograft (Ross procedure) had the first priority and stentless tissue valve had second for the ARR because of the better adaptation to the tissue. However, pulmonary autograft was not used in the patients with Marfan disease (patient 6) or annuloaortic ectasia (patient 7). The details of surgical procedures are summarized in Table 2. Annular reconstruction was performed in 2 patients (patients 1 and 8), and closure of fistula was done in 2 patients (patients 3 and 6) using autologous in 2 patients and xenogenic pericardium in 2 (Xenomedica, 1; Edwards Lifesciences, Irvine, CA; Periguard, 1; BioVascular, Inc, St. Paul, MN). To perform ARR with autograft or stentless full root, we reconstructed a neoannulus with the xenogenic or autologous pericardium using 4 – 0 Prolene (Ethicon, Somerville, NJ) onto the destructed annulus, followed by ARR. Fibrin glue saturated with antibiotics (amikacin sulfate, 2; tobramycin, 1; imipenem/cilastatin sodium, 1) was applied in 5 patients. The grafts for ARR consisted of
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MAP ⫽ mitral LV ⫽ left ventricle; AVR ⫽ aortic valve replacement; LA ⫽ left atrium; LCC ⫽ left coronary cusp; LMT ⫽ left main trunk; RCA ⫽ right coronary artery; RCC ⫽ right coronary cusp; RV ⫽ right ventricle. ARR ⫽ aortic root replacement; NCC ⫽ non coronary cusp; Ao ⫽ aorta; annuloplasty;
Xenogenic annular reconstruction AVR (Freestyle 23 Subcoronary) LCC-RCC NCC-RCC (180°) 8
1) AVR (SJM25) 2) Cabrol AVR (CEP23) 7
ARR (Prima Plus 25)
— AVR Omniscience 23 Bentall (SJM25) 4 5 6
Ross Ross — — 2 3
LCC, RCC (180°) LCC, RCC (270°) Ao-RV fistula LCC, RCC (90°) RCC, NCC (180°) LCC (180°); LV-LA fistula graft infection LCC (270°) graft infection
Ross Ross failure, ARR (Freestyle 27) ARR (Freestyle 25)
Amikacin sulfate
— — Imipenem, cilastatin sodium Amikacin sulfate — —
Omentum; rifampicin-soaked graft; CABG (LMT, RCA) —
Tobramycin Tobramycin — —
CABG, RCA
— —
Autologous annular reconstruction — Autologous Ao-RV fistula closure — — Xenogenic LV-LA fistula closure — Ross LCC (120°) — 1
No
Previous operation
LV-Ao Discontinuity Site (degree)
Operation
Patch Plasty
Topical Antibiotics
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Others
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Table 2. Previous Operative Modes and Details of Left Ventricular-Aortic Discontinuity and Surgical Repair
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pulmonary autografts in 4 patients and stentless porcine valve in 4 (Freestyle, Medtronic Inc in 3; Prima Plus, Edwards Lifesciences in 1). One stentless porcine valve was selected after the failure of Ross procedure (patient 5). In patient 7, who had a MRSA-contaminated prosthetic aortic graft, a rifampicin-soaked graft (Gelsoft 20 mm; Vascutek Ltd, Renfrewshire, Scotland) was implanted, covered by the greater omentum. In patients 6 and 7, who had destroyed coronary ostia, coronary artery bypass grafting (CABG) was also performed. Saphenous vein grafts were placed on the right coronary artery in patient 6 and on the left main trunk and the left coronary artery in patient 7.
Statistical Analysis The data are expressed as mean ⫾ standard deviation. The freedom from cardiac events was assessed by the KaplanMeier method using SPSS software (SPSS Inc, Chicago, IL).
Results Early Results No hospital death was observed. Cardiopulmonary bypass time was 378.9 ⫾ 119.4 minutes, myocardial ischemic time was 249.5 ⫾ 53.2 minutes, and the intraoperative transfusion requirement was 36.0 ⫾ 46.0 U. Postoperative profiles of the patents are summarized in Table 3. Postoperative intensive care unit stay was 4.2 ⫾ 4.5 days, and hospitalization was 56.6 ⫾ 9.1 days. Morbidity included complete A-V block in patient 3 (transient). Patient 5 had low output syndrome and atrial fibrillation, and required mediastinal reexploration for bleeding and prolonged respiratory support. Patient 8 had liver cirrhosis in Child-Pugh class B had postoperative massive ascites.
Mid-Term Results Average follow-up was 38.3 ⫾ 28.6 months (range, 4 to 78 months). No late death was observed. Patient 2, who had undergone a Ross procedure, had valve sparing (neoaortic valve) root replacement 3 years after the first operation because of pulmonary autograft dilatation with severe valve regurgitation; this was followed by AVR after 1 month owing to valve insufficiency with fenestration of the preserved neoaortic valve. Freedom from major adverse cardiac events was 100% at 3 years and 66.7% at 5 years after operation (Fig 2). No recurrent infection was observed during the follow-up.
Comment Because surgical treatment for heart valve diseases is complicated by infection, which is likely to result in increased morbidity and mortality, the selection of the surgical strategy requires careful attention. Severe NVE or PVE often destroys the annulus and results in the formation of an aortic root abscess. The operative mortality rate is still disappointing, with reports 9.4% to 32% [1–3], and freedom from reoperation is as low as 45%, particularly with PVE cases at 1 year after operation [5].
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Fig 1. (A) Preoperative echocardiogram in patient 7. The asterisk (*) clearly indicates the part of left ventricle (LV)–ascending aorta (Ao) discontinuity. The large abscess cavity was extended back adjacent to the left atrium with pseudoaneurysm formation. The arrow points to the St. Jude Medical (SJM) valve. (LA ⫽ left atrium). (B) Intraoperative findings of the aortic root from the surgeon’s view. (C). Schema for the intraoperative photo. A cannula for selective coronary perfusion was inserted into each coronary artery. Dotted line circled the extent of pseudoaneurysm. (CP ⫽ cardioplegia; LCA ⫽ ostium of left coronary artery; MV ⫽ mitral valve; RCA ⫽ ostium of right coronary artery.)
In the literature, aortic root abscess secondary to infective endocarditis is one of the major causes of LV-Ao discontinuity [4], which penetrates into the adjacent structures such as the right/left atriums and ventricles. A greater part of circumference of the annulus loses its connection with the left ventricle, sometimes just leaving the aortomitral continuity. Surgical outcome for advanced active infective endocarditis has not been satisfactory, particularly in PVE patients who require ARR. Leyh and colleagues [6] reported the excellent long-term results of the ARR in patients with prosthetic active PVE regardless of the graft materials; however, the hospital mortality rate was still high as high as 18.5% [6]. Although our experience comprised a limited number of patients, no hospital or mid-term death occurred in this series. Because a delay in operation on the aortic root frequently causes a fatal complication, proper judgment for the timing of the operation is mandatory. Delahaye and
colleagues [7] pointed that the timing of the surgical intervention for infective endocarditis tended to be delayed despite guidelines on the surgical management for infective endocarditis. The longer the delay, the greater destruction of the aortic root and the more complicated the surgical procedure becomes. The advanced annular lesion, such as the LV-Ao discontinuity, was observed in as many as 9 patients (9.3%) of all ARRs, and 8 of them with destructive aortic valve endocarditis were involved in the current study in our institute. Seven patients (78%) were in NYHA class III or higher, 4 patients (44%) were in the status of intractable congestive heart failure, and 1 was in septic shock. Advanced annular abscess sometimes causes intracardiac fistulas, such as to the left ventricular outflow tract and the right/left atriums [8], as occurred in our patients 3 and 6. As Leyh and colleagues [6] recommended, aggressive, radical débridement is indispensable for the success of
Table 3. Postoperative Patient Profiles Duration of Inotrope Support
Respiratory Support
ICU stay, days
Hospital stay, days
Post-op antibiotics
Complications
1 2
29 hours 96 hours
7 hours 24 hours
2 3
47 65
VCM, AMK, PAPM/BP VCM, AMK
3
48 hours
7 hours
4
62
PCG, AMK
4 5
11 hours 52 days
2 hours 60 days
1 15
53 67
SBTPC, AMK FMOX, AMK
6 7 8
4 days 12 hours 4 hours
10 hours 14 hours 35 hours
3 3 2
49 65 45
VCM, AMK, IPM/CS VCM, AMK SBTPC, AMK
AF Drug-induced hepatitis Transient A-V block Liver dysfunction Bleeding, LOS, AF, prolonged respiratory support AF — Ascites, prolonged respiratory support
No
AF ⫽ atrial fibrillation; AMK ⫽ amikacin sulfate; syndrome; PAPM/BP ⫽ panipenem/betamipron; hydrochloride.
FMOX ⫽ flomoxef sodium; IPM/CS ⫽ imipenem/cilastatin sodium; LOS ⫽ low output PCG ⫽ penicillin potassium; SBTPC ⫽ sultamicillin tosylate; VCM ⫽ vancomycin
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Fig 2. Freedom from major adverse cardiac event. Cardiac event-free rates at 3 and 5 years after operations were 100% and 66.7%, respectively.
treatment of aortic root abscess; however, the débridement sometimes produces excessive annular tissue defect. Reconstruction of destroyed annulus by autologous or xenogenic pericardium is required to secure the pulmonary autograft, allograft, or stentless tissue valve. Two patients in the present series required annular reconstruction with autologous or xenogenic pericardium. When ARR is required because of infective endocarditis in native or prosthetic valves, allograft has been recommended as the valve of choice rather than mechanical or bioprosthetic valves [9], and is particularly useful in patients with PVE complicated by abscess or paravalvular leakage, or both [10]. Others have reported that excellent long-term results could be achieved regardless of the material used for ARR in patients with PVE [6, 11]. In the current study, ARR was primarily applied in all cases except in 1 patient, who had advanced liver cirrhosis (Child type B) with thrombocytopenia and required a less-invasive surgical mode. Considerations for the ideal graft conduit for the patients with LV-Ao discontinuity are: 1. The conduit is viable tissue, which is expected to be effective against bacterial infection. 2. It should have mechanically better fitting property towards irregular annular plane after the complete débridement. 3. A constant and prompt supply of the grafts is guaranteed for emergency cases. Published reports indicate allograft has been the ideal material for ARR [9, 12]; however, it is difficult to obtain the graft with requested size, particularly for urgent or emergency cases. For the reconstruction of the destroyed aortic root, prosthetic composite graft, pulmonary autograft, or stentless tissue valve are one of the practical alternatives. Prosthetic composite graft has superiority in terms of availability, and Leyh and colleagues [6] have reported that excellent long-term results could be
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achieved regardless of the material used for ARR in patients with PVE. In our opinion, however, some difficulties occur with prosthetic composite grafts in obtaining complete tissue adaptation for the destroyed annulus. Residual dead space may cause recurrent infection during follow-up. The Ross procedure using the root replacement technique has been reported to demonstrate excellent longterm survival and low thromboembolic and endocarditis risk [13]. This procedure is an excellent therapeutic option for active aortic valve endocarditis, with low morbidity and mortality including a very low recurrence rate of endocarditis [14 –17]. Because pulmonary autograft is viable tissue, it is more resistant to infection and is suitable for the irregular ARR after aggressive débridement. However, the Ross procedure has potential risk of the necessity for reconstruction of the right ventricular outflow tract (RVOT). A stentless tissue valve was selected for the reconstruction in 4 patients, who had no calcification or stenosis during a follow-up of 53 months.. So far, we have not experienced any problem in the RVOT, but further investigation should be determined. Patients with Marfan syndrome (patient 6) or annuloaortic ectasia (patient 7) were excluded from Ross procedure because of possible future annular dilatation. Although it remains unclear whether the stentless tissue valve is resistant to infection, it could be a first alternative to pulmonary autograft or allograft in the treatment of severe destructive aortic root disease [18 –20]. Topical application of antibiotics still remains controversial. Several reports on the efficacy of the topical use of antibiotics in vitro and in vivo concluded that pretreatment of prosthetic Dacron (DuPont, Wilmington, DE) grafts with antibiotic/fibrin compound resulted in binding of a sufficient amount of antibiotics for at least 1 week [6, 21, 22]. We applied fibrin glue saturated with antibiotics into the cavity, and there was no recurrent infection; however, efficacy of topical application was unclear. The number of patients is too small to elucidate the important factors that contributed to the excellent outcome, and the follow-up was not long enough to conclude lack of complications in long-term follow-up. The efficacy of topical application of antibiotics on the prevention of recurrent infection was entirely unclear, although some articles have supported the hypothesis. Furthermore, the severity of the infection and the causative microorganism might vary among patients. In conclusion, excellent outcome during short- and mid-term follow-up can be achieved by radical exclusion of abscess cavity, followed by root replacement with a viable pulmonary autograft (Ross procedure) or stentless aortic root xenograft in patients with LV-Ao discontinuity caused by destructive endocarditis.
References 1. Glazier JJ, Verwilghen J, Donaldson RM, Ross DN. Treatment of complicated prosthetic aortic valve endocarditis with annular abscess formation by homograft aortic root replacement. J Am Coll Cardiol 1991;17:1177– 82.
2. Moon MR, Miller DC, Moore KA, et al. Treatment of endocarditis with valve replacement: the question of tissue versus mechanical prosthesis. Ann Thorac Surg 2001;71:1164 –71. 3. Watanabe G, Haverich A, Speier R, Dresler C, Borst HG. Surgical treatment of active infective endocarditis with paravalvular involvement. J Thorac Cardiovasc Surg 1994;107: 171–7. 4. Symbas PN, Vlasis SE, Zacharopoulos L, Lutz JF. Aortic-left ventricular discontinuity and aortic regurgitation from acute endocarditis. South Med J 1982;75:1476 – 8. 5. Delay D, Pellerin M, Carrier M, et al. Immediate and long-term results of valve replacement for native and prosthetic valve endocarditis. Ann Thorac Surg 2000;70:1219 –23. 6. Leyh RG, Knobloch K, Hagl C, et al. Replacement of the aortic root for acute prosthetic valve endocarditis: prosthetic composite versus aortic allograft root replacement. J Thorac Cardiovasc Surg 2004;127:1416 –20. 7. Delahaye F, Rial MO, de Gevigney G, Ecochard R, Delaye J. A critical appraisal of the quality of the management of infective endocarditis. J Am Coll Cardiol 1999;33:788 –93. 8. Bozbuga N, Erentug V, Erdogan HB, et al. Surgical treatment of aortic abscess and fistula. Tex Heart Inst J 2004;31:382– 6. 9. Haydock D, Barratt-Boyes B, Macedo T, Kirklin JW, 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 –9. 10. Lopes S, Calvinho P, de Oliveira F, Antunes M. Allograft aortic root replacement in complex prosthetic endocarditis. Eur J Cardiothorac Surg 2007;32:126 –30. 11. Hagl C, Galla JD, Lansman SL, et al. Replacing the ascending aorta and aortic valve for acute prosthetic valve endocarditis: is using prosthetic material contraindicated? Ann Thorac Surg 2002;74:S1781–5. 12. Sabik JF, Lytle BW, Blackstone EH, Marullo AG, Pettersson GB, Cosgrove DM. Aortic root replacement with cryopre-
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served allograft for prosthetic valve endocarditis. Ann Thorac Surg 2002;74:650 –9. Kouchoukos NT, Masetti P, Nickerson NJ, Castner CF, Shannon WD, Davila-Roman VG. The Ross procedure: longterm clinical and echocardiographic follow-up. Ann Thorac Surg 2004;78:773– 81. Birk E, Sharoni E, Dagan O, et al. The Ross procedure as the surgical treatment of active aortic valve endocarditis. J Heart Valve Dis 2004;13:73–7. Joyce F, Tingleff J, Pettersson G. The Ross operation: results of early experience including treatment for endocarditis. Eur J Cardiothorac Surg 1995;9:384 –91. Pettersson G, Tingleff J, Joyce FS. Treatment of aortic valve endocarditis with the Ross operation. Eur J Cardiothorac Surg 1998;13:678 – 84. Schmidtke C, Dahmen G, Sievers HH. Subcoronary Ross procedure in patients with active endocarditis. Ann Thorac Surg 2007;83:36 –9. Katsumata T, Vaccari G, Westaby S. Stentless xenograft repair of excavating aortic root sepsis. J Card Surg 1998;13: 440 – 4. Muller LC, Chevtchik O, Bonatti JO, Muller S, Fille M, Laufer G. Treatment of destructive aortic valve endocarditis with the Freestyle Aortic Root Bioprosthesis. Ann Thorac Surg 2003;75:453– 6. Sakaguchi T, Sawa Y, Ohtake S, Hirata N, Matsuda H. The Freestyle stentless bioprosthesis for prosthetic valve endocarditis. Ann Thorac Surg 1999;67:533–5. Haverich A, Hirt S, Karck M, Siclari F, Wahlig H. Prevention of graft infection by bonding of gentamycin to Dacron prostheses. J Vasc Surg 1992;15:187–93. Karck M, Siclari F, Wahlig H, Sperling U, Schmid C, Haverich A. Pretreatment of prosthetic valve sewing-ring with the antibiotic/fibrin sealant compound as a prophylactic tool against prosthetic valve endocarditis. Eur J Cardiothorac Surg 1990;4:142– 6.
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