Ann Thorac Surg 2005;79:1397-1399
© 2005 The Society of Thoracic Surgeons
Case report
Stentless Bioprosthetic Aortic Valve Replacement After a Homograft Root Replacement: Toronto SPV Implantation After a Homograft Root
Faisal G. Bakaeen, MB, BChira,
Jon-Cecil M. Walkes, MDa,
Michael J Reardon, MDa,*
a The Methodist Hospital, Houston, Texas, USA
Accepted for publication October 8, 2003.
* Address reprint requests to Dr Reardon, 6560 Fannin St, No 1002, Houston, TX 77030-2761, USA
mreardon{at}tmh.tmc.edu
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Abstract
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Stentless bioprosthetic valves for the aortic position offer excellent hemodynamic characteristics, making them an attractive choice ahead of other valve prostheses. We present a unique case in which a patient underwent aortic valve replacement with a stentless porcine valve and mitral valve repair for severe aortic and mitral regurgitation 1 year after a homograft root replacement for acute aortic endocarditis. The rationale for our approach is outlined in the context of current surgical trends.
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Introduction
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There are several types of valves available to replace a diseased aortic valve and multiple factors impact the surgeon's choice. We utilized a stentless Toronto SPV bioprosthesis (St. Jude Medical, St. Paul, MN) in a surgical solution for a reoperative scenario associated with unusual pathology.
A 64-year-old woman presented with severe congestive heart failure 12 months after homograft root replacement for subacute bacterial endocarditis. Two years earlier the patient received an orthoptic liver transplantation for primary biliary cirrhosis and was receiving immunosuppression therapy, including steroids. Other significant medical history included insulin-dependent diabetes mellitus, rheumatoid arthritis, and hypertension.
At the time of the first cardiac operation, the patient had symptomatic aortic regurgitation with progressively worsening severity secondary to aortic endocarditis and underwent surgical excision of infected tissue and root reconstruction with 22-mm cryopreserved homograft (CryoLife Inc, Kennesaw, GA). The patient had no evidence of aortic valvular insufficiency on transesophageal echocardiography (TEE) at the conclusion of the surgery. She remained free of cardiac symptoms until the onset of mild dyspnea on exertion during the month before presentation.
The patient had sudden onset of dyspnea while she was working in her garden, and she came to the emergency room. She had severe congestive heart failure and an audible cardiac murmur. Transthoracic echocardiography showed moderately severe aortic and mitral regurgitation with a 55% ejection fraction, a mildly dilated left ventricle, and moderately dilated left atrium. These findings were confirmed by a TEE that showed normal root size, 19-mm aortic annulus, and failure of coaptation of the aortic leaflets. The mitral annulus measured 24 mm, and there was thickening of the mitral leaflets. There was a posterior regurgitant jet with a prolapsing A3 segment. There was no evidence of valvular vegetation, and the patient had no clinical signs of infection. Reoperation was recommended, and the surgical options were discussed with the patient, who expressed a strong desire to avoid postoperative anticoagulation treatment.
At reoperation, the homograft was opened in a transverse direction and completely transected above the valve commissures and the reimplanted coronary buttons (Fig 1). That gave adequate exposure of the valve that had foreshortened and the mildly thickened leaflets. There was no evidence of homograft calcification or endocarditis; the valve leaflets were excised, and the annulus of the homograft was debrided. The annulus and the graft were both sized to 21 mm with St. Jude Medical stentless obturators (St. Jude Medical, St. Paul, MN) and a 21-mm St Jude Toronto valve was inserted. The valve was seated with a proximal interrupted suture line in a horizontal plane at the most caudal extent of the homograft annulus. The commissural posts were than anchored inside the homograft with stay sutures of 4-0 polypropylene to achieve proper orientation and to ensure patency of the coronary buttons. The stentless porcine valve (SPV) distal suture line was completed by sawing the valve commissures to the homograft with running 4-0 polypropylene full-thickness suture line. The homograft was repaired primarily using a running 4-0 polypropyline suture (Fig 2). The mitral valve was repaired utilizing 5-0 Gore-Tex (W. L. Gore; Flagstaff, AZ) suture to suspend the A3 segment in addition to annuloplasty utilizing a 26-mm Future Band (Medtronic, Minneapolis, MN).
Pathologic examination of the excised homograft valve showed diffuse fibrous thickening. Focal areas of increased chronic inflammatory cells, mainly consisting of lymphocytes, were identified. Increased vascularity was also noted, with changes suggestive of a form of chronic valvulitis.
The patient's postoperative hospital course was unremarkable. A follow-up echocardiogram 1 month after surgery showed normal left ventricular function. The aortic root was again normal in size, and the SPV valve leaflets appeared normal. There was no atrial regurgitation and trace mitral regurgitation. The patient is clinically doing well at 10 months after reoperation.
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Comment
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The advantage of using a stentless bioprosthesis for aortic valve replacement has been well documented [1–3]. Given our patient's reluctance to undergo anticoagulation, a mechanical valve was not an option in this case. It would have been technically easier to implant a stented tissue valve, but only a very small bioprosthesis would have fit. Other reasonable options include root reconstruction with either a Freestyle stentless porcine aortic root or a homograft, but this would be a more complicated operation notwithstanding the mitral valve repair procedure also required in this case.
Ikonomidis and Miller [4] recently reported a successful implantation of a Toronto SPV in a 51-year-old woman with severe aortic regurgitation after a David-I-type valve-sparing aortic root replacement. Their experience and the case we describe here are unique because they involve an implantation of a stentless valve through the confines of a preexisting aortic graft. In our case hand, we have adopted our previously described technique of implantation of the Toronto SPV valve [5] with minor adjustments to account for the different anatomy as outlined above.
The use of aortic homograft facilitates reconstruction in complex aortic valve endocarditis and offers resistance to reinfection [6], hence the choice of a homograft at this patient's first operation. A valid concern in the case at hand is recurrent endocarditis affecting the stentless valve. Furthermore, although reports of the durability of stentless aortic valves have been encouraging [1, 3], it poses a significant concern especially in this patient who has already had a failed homograft reconstruction in a brief time span.
This case is unusual given the absence of the typical findings that are associated with allograft structural degeneration such as calcification and disfiguration. The finding of valvulitis manifested by leaflet pathology with gross sparing of the remaining components of the homograft is intriguing. That could be due to autoimmune factors related to the patient's history of rheumatoid arthritis, with further variables imposed by the history of liver transplantation and immunosupression. Native aortic valvulitis has been described in a variety of autoimmune disorders, and both granulomatous and nonspecific valvulitis have been reported in patients with rheumatoid arthritis [7]. A case of recurrent autoimmune valvulitis affecting an aortic bioprosthesis has been described in a patient with systemic lupus erythematosus [8]. Our case demonstrates the versatility of the stentless aortic bioprosthesis and its successful application in an operation tailored to the patient's specific variables.
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References
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- Dellgren G, Feindel CM, Bos J, Ivanov J, David TE. Aortic valve replacement with the Toronto SPV: long-term clinical and hemodynamic results. Eur J Cardiothorac Surg. 2002;21:698–702[Abstract/Free Full Text]
- Bach DS, Goldman B, Verrier E, et al. Impact of small valve size on hemodynamics and left ventricular mass regression with Toronto SPV stentless aortic bioprosthesis. J. Heart Valve Dis. 2002;11:236–241[Medline]
- Bach DS, Goldman B, Verrier E, et al. Eight-year hemodynamic follow-up after aortic valve replacement with the Toronto SPV stentless aortic valve. Semin Thorac Cardiovasc Surg. 2001;13(Suppl 1):173–179[Medline]
- Ikonomidis JS, Miller DC. Stentless bioprosthetic aortic valve replacement after valve-sparing aortic root replacement. J Thorac Cardiovasc Surg. 2002;124:848–851[Free Full Text]
- Reardon MJ, David TE. Stentless xenograft aortic valves. Curr Opin Cardiol. 1999;14:84–89[Medline]
- Dearani JA, Orszulak TA, Schaff HV, Daly RC, Anderson BJ, Danielson GK. Results of allograft aortic valve replacement for complex endocarditis. J Thorac Cardiovasc Surg. 1997;113:285–291[Abstract/Free Full Text]
- Ivenson JM, Thadani U, Ionescu M, Wright V. Aortic valve incompetence and replacement in rheumatoid arthritis. Ann Rheum Dis. 1975;34:312–320[Abstract/Free Full Text]
- Gordon RJ, Weilbaecher D, Davy SM, et al. Valvulitis involving a bioprosthetic valve in a patient with systemic lupus erythematosus. J Am Soc Echocardiogr. 1996;9:104–107[Medline]
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Abstract
Introduction
