Aortic Root Enlargement: Modified Manouguian Technique

The enlargement of the aortic annulus has demonstrated excellent results for avoiding patient-prosthesis mismatch (PPM). Aortic root enlargement (ARE) has been shown to be a safe and reproducible procedure. Several techniques are described in the literature, however, Nicks was a pioneer in describing the incision into the noncoronary sinus that allows aortic annulus enlargement (1). The benefit of this procedure is the implantation of a bigger valve prosthesis (by one or two sizes), thus avoiding PPM. The size of the aortic prosthesis should be proportional to the patient’s body surface. PPM is an important factor that affects mortality and morbidity.

Important Steps

1. A median sternotomy was performed. 
2. Cardiopulmonary bypass (CPB) was instituted with ascending aorta and right atrial cannulation through a two-stage cannula (Edwards Lifesciences, Irvine, California, USA).
3. Left heart venting from the right superior pulmonary vein was added.
4. The ascending aorta was clamped and antegrade and retrograde cardioplegia (CPL) with cold blood was performed.
5. A transversal aortotomy was started and the aortic valve was exposed.
6. The aortic valve was excised and the annulus was carefully debrided.
7. When the decalcification of the annulus was finished, the annulus was measured with the corresponding sizers. The decision to enlarge the aortic annulus was made according to the patient's body surface.
8. A dissection of the left atrium roof was made in order to make a clear incision.
9. A modified Manouguian technique was performed without entering into the left atrium or incising the anterior leaflet of the mitral valve (2).
10. The enlargement was achieved by extending the aortotomy into the fibrous tissue between the non-coronary cusp and the left coronary cusp and onto the subaortic curtain.
11. The reconstruction of the defect was done with a teardrop-shaped glutaraldehyde-treated patch of bovine pericardium. This patch was sutured with a 5.0 polypropylene suture (Prolene®, Ethicon, New Jersey, USA), starting at the nadir of the annular enlargement incision and extending up to 1 or 2 cm above the plane of the annulus. At this level, the authors used an extra suture to fix the enlargement suture line with 5.0 polypropylene.
12. The aortic annulus was resized.
13. Pledgeted 2.0 polyester sutures (TiCron®, Covidien, Dublin, Ireland) were placed circumferentially around the aortic annulus (placing them from the outside into the patch zone).
14. The sutures were placed in the prosthetic valve and then tied into place.
15. The aortotomy was closed using the patch to enlarge the aortic root with a 5.0 polypropylene suture in a continuous fashion.
16. After weaning from CPB, protamine was administered and the procedure was completed in a routine fashion.

The functions of the prosthesis and de-airing process were monitored with intraoperative transesophageal echocardiography. This technique allowed the implantation of a prosthetic valve one or two sizes larger than the original size of the aortic annulus.

References

1. Nicks R, Cartmill T, Bernstein L. Hypoplasia of the aortic root. The problem of aortic valve replacement. Thorax 1970; 25: 339-346.
2. Manouguian S, Seybold-Epting W. Patch enlargement of the aortic valve ring by extending the aortic incision into the anterior mitral leaflet. New operative technique. J Thorac Cardiovasc Surg 1979; 78(3): 402–12.