AORTIC VALVE REPLACEMENT
RELATED PROCEDURES
ENLARGEMENT OF THE AORTIC ANNULUS
- Narrow aortic annulus in patients with a large body-surface area disables implantation of a valve large enough (sufficient effective orifice area) to avoid patient–prosthesis mismatch (PPM).
- Specially modified prosthesis with increased valve orifice area via reduction and reshaping of the sewing ring (also of the housing) without changing the mechanism of the valve are available.
- Bioprostheses: have less favourable effective orifice area compared with mechanical valves, the sewing rings were reshaped to for supra-annular implantation.
- Stentless bioprostheses do not have a sewing ring or a stent; have larger effective orifice area than the stented bioprostheses.
- As a result, aortic annulus enlargement is rarely needed.
Partial Supra-annular Valve implantation:
- A simple technique that allows implantation of a disc prosthesis 2-4mm larger than the narrow aortic annulus.
- The prosthesis is sutured in the area of the non-coronary sinus in a supra-annular position.
- Pledgeted horizontal mattress sutures are passed from outside through the aortic wall a few millimetres above the annulus and through the sewing ring of the aortic valve prosthesis.
- It is important to orient the opening of the valve towards the non-coronary sinus.
Partial supra-annular valve implantation (in the area of the non-coronary valve)
Nicks procedure
- Aortic annulus enlargement procedure described by Nicks et. al. in 1970
- If the narrow annulus is suspected preoperatively the aortotomy is carried obliquely into the non-coronary sinus.
- Once the narrow annulus is confirmed the incision is prolonged deep into the non-coronary sinus, cuts the aortic annulus, and stops at the base of the anterior mitral leaflet.
- If needed, the incision can be carried farther across the fibrous mitral annulus into the anterior mitral leaflet.
Nicks Procedure: Enlargement of narrow aortic annulus
Red curve “neoannulus” in the non-coronary sinus
Red curve “neoannulus” in the non-coronary sinus
Manouguian and Seybold-Epting Technique:
- Described in 1979.
- The aortotomy is extended into the commissure between the left and non-coronary sinus and then into the anterior mitral leaflet.
- A patch from the pericardium or vascular graft is sutured into the incision and the resulting enlargement of the annulus makes the implantation of a one- to two-size-bigger valve feasible.
- The valve is sutured to the neoannulus in the patch area by mattress stitches with pledgets placed externally.
Enlargement of narrow aortic annulus according to Manouguian and Seybold-Epting
Red curve “neoannulus” in the commissure between left and non-coronary sinus
Red curve “neoannulus” in the commissure between left and non-coronary sinus
Two-Directional Aortic Annulus Enlargement
- Described the by Otaki et al. in 1997.
- Can be used when the conventional posterior root enlargement technique is not wide enough.
- The aortotomy has the shape of an inverted Y.
- One arm of the Y points to the non-coronary sinus
- The other arm cuts the annulus in the commissure between the right and left aortic cusps and continues into the septal myocardium.
- A substantial annulus enlargement is obtained after implantation of a butterfly-shaped patch from a Dacron (DuPont, Wilmington, Del.) graft.
Aortoventriculoplasty
- Introduced by Konno et al. in 1975.
- It is a demanding but unavoidable procedure in children with a tunnel fibromuscular subaortic stenosis with a hypoplastic aortic annulus.
- The aortic annulus is enlarged by implantation of a patch into the incised ventricular septum and another patch is required for the closure of the right ventricular incision.