Ann Thorac Surg 2003;75:1338-1339
© 2003 The Society of Thoracic Surgeons
How to do it
Composite aortic root replacement with a bovine pericardial valve conduit
Alan D. Hilgenberg, MD*a,
Bassem N. Mora, MDa
a Cardiac Surgical Division, Massachusetts General Hospital, Boston, Massachusetts, USA
Accepted for publication September 16, 2002.
* Address reprint requests to Dr Hilgenberg, Warren 735, Massachusetts General Hospital, Boston, MA 02114, USA
e-mail: ahilgenberg{at}partners.org
 |
Abstract
|
|---|
In order to offer selected patients undergoing composite aortic root replacement the advantages of a tissue valve, we have constructed conduits intraoperatively by suturing a stented bovine pericardial valve (Edwards Lifesciences LLC, Irvine, CA) inside of a Dacron tube graft (Boston Scientific Corp, Natick, MA). The conduit is quickly made from readily available materials, is easily implanted, and can accommodate any of the anatomic situations encountered in repair of aortic root aneurysms. It is particularly suitable for patients 65 years of age and older.
|
Introduction
|
|---|
Composite aortic root replacement with direct coronary artery implantation has proven to be a reliable and durable procedure for repair of aortic root aneurysms with concomitant involvement of the aortic valve [1]. Traditionally a mechanical valve conduit has been implanted in order to maximize valve durability. Because of the disadvantages of anticoagulation and thromboembolism associated with mechanical valves, there is considerable interest in valve preservation techniques applied to aortic root aneurysm repair [2]. However, valve preservation is sometimes impossible because of leaflet pathology such as calcification, perforations, or prolapse. In order to offer selected patients undergoing composite aortic root replacement the advantages of a tissue valve, we have used an operation in which a composite graft is fashioned intraoperatively from a Carpentier-Edwards bovine pericardial valve (Edwards Lifesciences LLC, Irvine, CA) and a Hemashield graft (Boston Scientific Corporation, Natick, MA).
|
Technique
|
|---|
After opening the aneurysm, the aortic valve leaflets are excised, and the annulus is measured with pericardial valve sizers. The appropriate size valve with the standard sewing ring is selected and rinsed. During preparation of the valve, the aortic root aneurysm is excised, and buttons surrounding the coronary ostia are fashioned. A Hemashield graft whose diameter is 5 mm larger than the valve size is brought onto the field. The rinsed valve on its holder is placed inside of the graft, and the end of the graft is sutured to the sewing ring of the valve with two 3-0 polypropylene sutures (Fig 1).
One of the longitudinal black lines on the graft is positioned next to one of the valve struts, and the other black line on the graft will then be located in the middle of the opposite leaflet. Using a felt-tipped marking pen, two lines are placed on the outside of the graft corresponding to the two unmarked valve struts. The time for completion of the conduit averages 6 to 7 minutes.
View larger version (167K):
[in this window]
[in a new window]
|
Fig 1. Completed anastomosis of the sewing ring of the pericardial valve and the end of the Hemashield graft.
|
|
The conduit is implanted with interrupted 2-0 plegetted valve sutures (Fig 2).
The black line on the graft adjacent to the middle of the pericardial valve leaflet is placed posteriorly, as this helps to position the opening for the left coronary implantation. After the valve sutures are tied and cut, the left and right coronary buttons are implanted into the Dacron graft with continuous 4-0 polypropylene sutures. Fibrin glue is applied to both of the coronary anastomoses and to the annular suture line. The operation is completed by performing the distal anastomosis of the graft to the divided aorta, frequently with hypothermic circulatory arrest.
|
Comment
|
|---|
For patients who require aortic root aneurysm repair and cannot have a valve sparing operation, insertion of a pericardial valve conduit allows older patients and those with a contraindication to anticoagulation to have the advantages of a tissue valve. In our experience, the only patients having this operation who received warfarin are those with persistent atrial fibrillation; the others have simply been given aspirin.
Other tissue conduits that could possibly be used in older patients for aortic root aneurysm repair include homografts and stentless porcine xenograft roots. Homografts may not be readily available in the larger diameters and lengths often required in aneurysm repair. A stentless porcine root graft would need a Dacron graft extension in most aneurysm repairs resulting in an additional aortic suture line. Furthermore, most patients undergoing aortic root replacement have annulus diameters large enough to accommodate a stented valve with a low gradient, making a stentless valve less advantageous. The components for the conduit we have described are readily available in a full range of sizes so that any annulus and distal aorta can be readily accommodated.
The reason to construct the conduit during the cross-clamp time is to insure that the correct valve size is chosen; the added clamp time is minimal. A Dacron graft with a diameter 5 mm larger than the valve size has consistently allowed a comfortable fit between the end of the graft and the sewing ring of the valve. This also leaves enough room between the valve leaflets and the graft wall to simulate sinuses of Valsalva. Distally, the graft can be tailored to accommodate any aortic diameter and length.
The major concern regarding this operation is the durability of the pericardial valve, and the risk and complexity of a reoperation in the event of structural valve dysfunction. We anticipate that the durability of the pericardial valve used in this application will be similar to that of valves implanted into the native aorta. However, it is possible that the rigid Dacron graft that surrounds the valve in this conduit could result in more stress being applied to the leaflets compared with the more compliant native aorta. Sizing the graft as large as we do should help to preserve leaflet durability by avoiding contact of the leaflets with the inner wall of the graft.
It has been estimated that patients aged 65 years and older who have aortic valve replacement with a Carpentier-Edwards pericardial valve experience less than a 10% incidence of reoperation for structural valve dysfunction because of the competing risk of death [3]. If reoperation to replace the valve were necessary, we theorize that it could be done in some patients without the need to completely redo the conduit and reimplant the coronaries. By exposing the valve through a transverse incision in the graft just distal to the right coronary artery, the bioprosthesis could be removed by cutting through the sewing ring inside of the graft. Part of the sewing ring and the sutures would remain attached to the outside of the graft. Mattress sutures could then be placed from the ventricular side of the annulus passing outside to the inside of the graft. These sutures could be used to implant the next smaller size aortic valve. If this operation were not possible, then removal of the conduit and root re-replacement would be necessary.
We have implanted pericardial valve conduits in 23 patients whose average age was 68 years. All patients survived the initial hospitalization, and no late reoperations on the aortic root or valve have been required to date. This procedure has been successful in avoiding the risks of a mechanical valve conduit in older patients. It is likely that the incidence of reoperation for structural valve dysfunction in the elderly patients will be low and similar to that for patients who have had isolated aortic valve replacement with the pericardial valve. Perhaps the manufacturer of the bovine pericardial valve would consider making this composite conduit commercially available.
|
References
|
|---|
- Hilgenberg A.D., Akins C.W., Logan D.L., et al. Composite aortic root replacement with direct coronary artery implantation. Ann Thorac Surg 1996;62:1090-1095.[Abstract/Free Full Text]
- David T.E., Armstrong S., Ivanov J., Feindel C.M., Omran A., Webb G. Results of valve–sparing operations. J Thorac Cardiovasc Surg 2001;122:39-46.[Abstract/Free Full Text]
- Banbury M.K., Cosgrove D.M., White J.A., Blackstone E.H., Frater R.W.M., Okies J.E. Age and valve size effect on the long-term durability of the Carpentier-Edwards aortic pericardial bioprosthesis. Ann Thorac Surg 2001;72:753-757.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
G. Gatti, B. Benussi, A. Pappalardo, and B. Zingone
Aortic root replacement with a valved conduit containing a stented xenograft
Eur. J. Cardiothorac. Surg.,
April 1, 2008;
33(4):
740 - 741.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. P. Urbanski
Aortic valved conduit with a stented xenograft
Ann. Thorac. Surg.,
July 1, 2004;
78(1):
385 - 385.
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. D. Hilgenberg and B. N. Mora
Aortic valved conduit with a stented xenograft: Reply
Ann. Thorac. Surg.,
July 1, 2004;
78(1):
385 - 386.
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
