Interact CardioVasc Thorac Surg 2008;7:919-921. doi:10.1510/icvts.2008.182915
© 2008 European Association of Cardio-Thoracic Surgery
Brief communication - Cardiac general |
Prosthetic valve sparing aortic root replacement: an improved technique
Marzia Leacche,
Jorge M. Balaguer,
Ramanan Umakanthan and
John G. Byrne*
Vanderbilt Heart and Vascular Institute, Nashville, TN, USA
Received 1 May 2008;
received in revised form 9 June 2008;
accepted 11 June 2008
*Corresponding author. Vanderbilt University Medical Center, Department of Cardiac Surgery, 1215 21st Avenue South, Nashville, TN 37232-8802, USA. Tel.: +1 (615) 343 9195; fax: +1 (615) 343-5248.
E-mail address: john.byrne{at}vanderbilt.edu (J.G. Byrne).
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Abstract
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We describe a modified surgical technique to treat patients with a previous history of isolated aortic valve replacement who now require aortic root replacement for an aneurysmal or dissected aorta. This technique consists of replacing the aortic root with a Dacron conduit, leaving intact the previously implanted prosthesis, and re-implanting the coronary arteries in the Dacron graft. Our technique differs from other techniques in that we do not leave behind any aortic tissue remnant and also in that we use a felt strip to obliterate any gap between the old sewing ring and the newly implanted graft. In our opinion, this promotes better hemostasis. We demonstrate that this technique is safe, feasible, and results in acceptable outcomes.
Key Words: Root replacement; Reoperation; Aortic valve prosthesis
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1. Introduction
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Aortic root aneurysms and dissections in patients with a previous history of aortic valve replacement (AVR) is a challenging problem [1, 2]. The two options, provided the previously implanted prosthesis is functioning well, are to either re-replace the aortic valve prosthesis and the aortic root or to preserve the prosthesis and replace only the aneurysmal or dissected aortic root. We present two patients in whom we adopted the latter technique.
1.1. Case#1
A 21-year-old female who underwent AVR with a 23 mechanical St. Jude® valve and presented 10 years later with a 7-cm ascending aortic aneurysm involving the aortic root.
1.2. Case#2
A 76-year-old male who underwent AVR with a 25-mm Carpentier-Edwards® pericardial valve and presented two years later with a 7-cm aortic root aneurysm involving a dissection limited to the aortic root.
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2. Technique
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Because the aneurysms were adjacent to the sternum in both patients, we dissected and cannulated the femoral vessels and initiated cardiopulmonary bypass before the re-sternotomy. After careful reopening and meticulous dissection of previous adhesions, systemic moderate hypothermia was implemented. The aorta was cross-clamped and myocardial protection was achieved using antegrade and retrograde cardioplegia. The ascending aorta was transected, both coronary buttons were mobilized, and all the aortic tissue was resected down to the old prosthesis (Fig. 1a). A Hemashield® tube graft, 3 mm larger in diameter than the previously used aortic valve prosthesis, was chosen for the next stage of the operation.
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Fig. 1. (a) The coronary ostia are mobilized and the aneurysm is resected down to the aortic prosthesis. (b) A series of interrupted sutures starting outside the aorta are placed through the remnant aorta, then through the old sewing ring, and then through the Hemashield® graft.
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A series of interrupted 2-0 single-armed Ethibond® simple sutures were placed circumferentially through the old prosthetic valve sewing ring, approximately 1 mm apart. Each suture incorporated any residual aortic root tissue attached to the old prosthetic valve sewing ring in an outside-in fashion. After all sutures were in place, each of them was placed through the lower end of the Hemashield® graft in an inside-out fashion (Fig. 1b). A felt strip was then placed at the point of apposition between the graft and the old sewing ring within the loop of each suture (Fig. 2). After all the sutures were tied down, this area was reinforced with biologic glue. Using the eye cautery, orifices were made in the lower end of the Hemashield® graft to accommodate the implantation of the left and right coronary artery ostia buttons, each buttressed with pericardium. Hemostasis of each button was tested by infusing cardioplegia and pressurizing the Hemashield® graft, which was clamped distally. The distal anastomosis between the graft and the native ascending aorta was performed using running 4-0 Prolene suture buttressed with Teflon felt. Both patients had an uneventful postoperative course and were discharged home in excellent condition.
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Fig. 2. A strip of felt is placed between the two ends of the sutures circumferentially. The Hemashield® graft is seated on the old sewing ring.
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3. Discussion
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Different techniques have been used to treat patients with a new aortic root aneurysm in the presence of a previous AVR. The conventional approach consists in resecting the aneurysm, removing the old prosthesis, and reconstructing the aortic root. The choices are a mechanical valved-conduit or a biological aortic root. Kurisu et al. [3] have suggested, in the presence of a bioprosthesis, to leave the sewing ring of the original bioprosthesis and to resect the bioprosthesis leaflets, amputating the struts and suturing the skirt of a composite graft to the preserved sewing ring.
As an alternative, prosthetic valve sparing root replacement can be performed. Pacini et al. [4] have used a version similar to our technique in four patients with good results. Their technique consists in sewing a vascular graft to the sewing ring of the previous valve prosthesis. The authors leave a 4-mm aortic tissue remnant and then suture the edge of the aortic wall and the proximal portion of the tube graft. Our technique differs in that we do not leave any aortic tissue remnant. We bring the graft down to the sewing ring of the prosthesis, which minimizes the potential for bleeding from the proximal suture line and also serves as a strong backstop against which to sew. We believe that all aortic tissue needs to be excluded or removed because it is friable and may tear and result in bleeding, pseudoaneurysm formation or dissections. The second difference is that we use a felt strip in the loop between the two ends of each suture circumferentially, so that any gap between the old sewing ring and the newly implanted Hemashield® graft is obliterated. In our opinion, this intervention assists in achieving better hemostasis.
Correctly sizing the tube graft is a cardinal step to avoid a mismatch between the Hemashield® graft and the old prosthetic valve sewing ring. We found that a Hemashield® graft 3 mm larger than the prosthesis diameter represented an adequate match. Coronary artery re-implantation is another critical maneuver. We favor direct re-implantation of the coronary ostia and use buttressed pericardial strips to improve hemostasis.
Although the concept of preserving a previously inserted aortic prosthesis during ascending aortic replacement is not a new one, we have shown that our modified technique for prosthetic valve sparing root replacement can be safely performed in patients with aortic root pathology after previous AVR. In future operations, we could further optimize this technique by placing an additional running suture between the remaining part of the Sinus of Valsalva and the sewing ring of the valve prosthesis to provide an additional margin of safety for surgical hemostasis. The herein reported technique is feasible and provides the advantages of avoiding the explantation of a well-functioning prosthesis and reducing the magnitude of the operation.
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Acknowledgements
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We would like to thank Dominic Doyle, MA for the illustrations provided.
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References
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- Dougenis D, Daily BB, Kouchoukos NT. Reoperations on the aortic root and ascending aorta. Ann Thorac Surg 1997;64:986–992.[Abstract/Free Full Text]
- Kirsch EW, Radu NC, Mekontso-Dessap A, Hillion ML, Loisance D. Aortic root replacement after previous surgical intervention on the aortic valve, aortic root, or ascending aorta. J Thorac Cardiovasc Surg 2006;131:601–608.[Abstract/Free Full Text]
- Kurisu K, Ochiai Y, Kajiwara T, Kumeda H, Tominaga R. A modified valve-on-valve approach for aortic root replacement. Ann Thorac Surg 2003;76:2099–2101.[Abstract/Free Full Text]
- Pacini D, Villa E, Martin-Suarez S, Bartolomeo RD. Aortic root substitution after aortic valve replacement: a prosthesis-sparing operation. Eur J Cardiothorac Surg 2005;27:717–719.[Abstract/Free Full Text]
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Abstract
1. Introduction