Volume 11, Issue 1 , Pages 16-21, Spring 2006
Patch Enlargement of the Aortic Annulus using the Manouguian Technique
Article Outline
Technical challenge of the small aortic root has inspired the development of techniques for annular enlargement including the Konno, the Nicks, and the Manouguian. The latter, the subject of this article, is perhaps the most anatomical, with enlargement centered in the fibrous continuity between the aortic and mitral valves. Because the aortic incision lies at the commissure between left coronary cusp and noncoronary cusp, it is most readily applied when one has opened the aorta transversely rather than with a “hockey-stick” incision into the noncoronary cusp. Many surgeons prefer a transverse incision as it can be extended to provide a wide and symmetric view of the aortic valve, which may be preferable when contemplating valve repair or implanting a stentless prosthesis. At its extreme the aorta may be completely transected, providing the best possible view of the valve. A transverse aortotomy also avoids the tendency for inadvertent tearing of the aortotomy as the valve sutures are tied. From such an incision either the Nicks or the Manouguian enlargement can be accomplished.
Aortic root enlargement techniques can be applied with little added complexity to the procedure. Indeed, given data concerning the increased operative risk with severe patient–prosthesis mismatch, it is arguable that as an alternative to implantation of too small a prosthesis root enlargement may actually reduce mortality. Of course, as with any surgical procedure, the results will depend on experience and a full understanding of the principles underlying the technique.
Operative Technique
Fig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6
Figure 1.
The aortotomy from which the Manouguian root enlargement is most readily applied is a relatively low, transverse one. A hockey-stick-type aortotomy which initially descends into the middle of the noncoronary sinus will be more complex to close if diverted posteriorly to the commissure between right and left cusps.
Figure 2.
The Manouguian technique, in contrast to the Nicks, places the incision into the anterior leaflet of the mitral valve squarely in the center of the anterior leaflet. Recall that the right fibrous trigone of the mitral valve lies roughly at the base of the noncoronary cusp and the left fibrous trigone lies roughly at the base of the left coronary cusp beneath the left main. Therefore, incisions made deep into the noncoronary cusp, as is the case for the Nicks annular enlargement, run the risk of damage to the coapting surface of the mitral valve if not diverted medially. With the Manouguian, no such correction away from the free edge of the leaflet is necessary.
Figure 3.
A patch is then sewn into the defect in the anterior leaflet. The patch material may be autologous pericardium, glutaraldehyde-fixed bovine pericardium, or Dacron patch material. I prefer to use a running suture line beginning at the apex of the incision and carrying it just far enough above the surgical annulus of the aortic valve to permit placement of valve sutures. This leaves the aortotomy open as widely as possible for placement of the valve.
Figure 4.
The valve sutures are then placed. It is my preference to use horizontal mattress sutures with pledgets on the ventricular side. I anticipate that the patch will enlarge the root by one valve size and select my valve accordingly. In other words, if only a 19-mm valve fits before root enlargement, I select a 21-mm valve to insert after patch augmentation of the annulus.
Figure 5.
I place the valve sutures through the pericardial patch from outside to inside, using one mattress suture at each end of the patch, overlapping my continuous suture line, thereby reinforcing the patch closure.
Figure 6.
At this point the valve can be readily seated and the aortotomy closed with the continuous suture line. The large patch may be used to close the entire aortotomy, or more commonly I will make the patch just large enough to correct the defect in the root, ending it at my transverse suture line above the sinotubular junction.
The Achilles’ heel of the Manouguian operation must be acknowledged. As one descends into the anterior leaflet of the mitral valve, one runs the risk of creating a hole in the dome of the left atrium where it attaches to the fibrous continuity between aortic and mitral valves. These defects can be closed with the valve sutures, or with separate pledgeted mattress sutures. Meticulous closure of any such holes is necessary before one removes the cross-clamp, as this is a relatively inaccessible region after weaning from bypass.
Conclusions
We have applied root enlargement liberally in our practice as an alternative to a stentless valve or homograft implantation. It is our view that this is a more straightforward technique than root replacement and can be readily taught. It also has the distinct advantage that one may apply these techniques on the fly during routine aortic valve replacement without requiring that special supplies or equipment be stocked. One need not alter one’s planned operation significantly, for example, choosing to substitute a root-replacement-type technique as would be required for stentless valve implantation. These techniques are also readily utilized by surgeons in institutions that do not stock stentless valve prostheses and/or homografts. Finally, reoperations performed on patients who have had these types of root enlargement techniques are relatively straightforward in comparison to prior root replacement techniques. Review of our experience at Mayo Clinic has demonstrated no incremental risk in aortic valve replacement attributable to root enlargement itself.
PII: S1522-2942(06)00031-6
doi:10.1053/j.optechstcvs.2006.03.003
© 2006 Elsevier Inc. All rights reserved.
Volume 11, Issue 1 , Pages 16-21, Spring 2006
