Mitral valve replacement in patients with mitral annulus abscess

1 The infected mitral valve is removed along with all infected tissue in the annulus.

2 Note the raw open area in the posterior annulus after removal of the infected annulus. Valve sutures cannot be secured to this area, and it may also communicate with the epicardium.

3 Autologous pericardium is the best material to reconstruct defects in the posterior annulus. Pericardium is normally removed from the left side on initial opening the chest. The patch is sewn to healthy myocardium inside the ventricular cavity beyond the area of damage. The optimal suture material is 4-0 polypropylene with a large ½ circle taper needle. Large bites are used and the first part of this suture line is performed in an “open” fashion. Because it is very easy to inadvertently plicate the annulus, a conscious effort must be made to make the patch bites wider than those in the ventricular muscle. The size of the valve should be determined only after the patch is sewn into position.

4 The patch is gently pulled down using a nerve hook and taking care not to pull sutures out of the soft myocardium. The sutures should be pulled snugly but not to the point of pulling through the relatively friable muscle. Remember, the patch will be compressed against the ventricular muscle when the heart is working so a tight seal is usually not necessary. The suture line is continued in each direction towards the area of healthy annulus. At this point, the suture is secured to the annulus by tying it to an additional anchoring suture. Depending on the integrity of the debrided atrial area, the atrial side of the patch is either sewn or left unsewn to the atrial wall. If left unsewn, it is important to trim any redundant patch material that could be drawn into the valve mechanism.

5 The annulus is measured to determine the size of prosthesis to insert. The choice between a mechanical or a biological prosthesis should be made based on patient factors as well as on a prediction by the surgeon as to the difficulty of a future redo operation should that become necessary. In our experience, the risk of early reinfection is not related to valve prosthesis type nor infecting organism.

6 Pledgeted 2-0 braided polyester valve sutures on ½ circle needle are placed around the annulus. Where the annulus is still intact the plegets are placed on the ventricular side. In the area reconstructed by the patch the sutures are take in and out on the patch as shown.

7 Sutures are placed into the prosthetic valve-sewing ring. In this case, a mechanical valve is being used.

8 Once the valve is in place, leaflet excursion is checked for any obstruction of motion. If need be, the valve can be rotated. Note in this figure that PTFE sutures have been used to reattach the papillary muscle heads to the mitral annulus.

1 As before, all infected material is removed. Note in this case the infected area involved most of the mitral annulus. However, the area between the anterior mitral leaflet and the aortic valve, the fibrous trigone is spared and can be used to secure a patch.

2 A circumferential patch of bovine pericardium is sewn around the annulus with a 3-0 polypropylene suture on a large ½ circle taper needle. In the area of the aortic valve, the sutures must only be secured to the fibrous trigone, taking great care not to injure the aortic valve leaflet which is inserted into the annulus in this area.

3 As before, the patch is carefully pulled snugly against the ventricular muscle. The free edge of the patch on the atrial side left unsewn. After the patch is in place, a new valve size is selected and sewn into position. Pledgets should be placed on the ventricular surface regardless of valve type used.

4 Sutures are placed into the sewing ring of the valve prosthesis and the valve secured into the newly fashioned annulus.