Surgical Techniques

The heart is cannulated for cardiopulmonary bypass utilizing ascending aortic cannulation relatively high near the innominate artery and dual vena caval cannulas. Prior to aortic cross-clamping, the aorta and pulmonary artery are fully mobilized. There are usually adhesions from previous operations. After induction of cardioplegic arrest, a vertical aortotomy is performed, begun anteriorly and directed slightly to the left of the right coronary ostia (Figure 36.1).

The aortotomy is retracted with two stay sutures, and the valve and subvalvular region are examined. If the valve annulus is more than two standard deviations smaller than is normal for that age, it is necessary to enlarge it to an adult size. If the subvalvular obstruction cannot be reasonably handled with a conservative resection, extended aortic root replacement (aortic root-Konno procedure) is performed. The incision in the aorta is extended into the annulus at the point between the left and right

Manouguian Procedure
Figure 36.1. Aortotomy for aortic root-Konno reconstruction.

coronary ostia, where the commissure is or normally would be. An oblique incision is then made in the right ventricular outflow tract meeting the aortotomy. It is angled toward the apex to avoid the base of the pulmonary valve. These incisions combine to open the top of the septum to view. The septum, which by definition is thick, is incised vertically toward the apex, and the incision is extended until the left ventricular outflow tract is widely open (Figure 36.2).

The coronary ostia are excised on large buttons and the aorta transected at or above (if narrowed) the level of the sinus ridge. The remainder of the proximal aortic root is excised, however, leaving the fibrous aortic tissue intact just above the membranous septum and not violating the aortic mitral continuity (Figure 36.3). The incision into the septum allows enlargement to the desired size, which is accomplished with Hegar dilators. The goal is to place, at the minimum, a 19 mm human aortic allograft, which means that a size 21 Hegar should fit generously into the opened left ventricular outflow tract.

The prepared allograft has been trimmed at its base, but coronary windows are not excised at this point. Pledgetted 4-0 monofilament sutures are placed with the pledgets on the ventricular side of the septal incision and passed as horizontal mattress sutures through the anterior leaflet of the mitral valve, the entirety of which is used to fill the septal defect. These sutures are sequentially placed until the level of the "true" annulus is reached (Figure 36.4).

At this point the suture technique is changed to 3-0 braided interrupted sutures in the manner of the aortic root replacement, as described by Ross. They are placed 1-2 mm apart, circumferentially through the annulus of the allograft and recipient. They are not placed as horizontal mattress sutures but, rather, as simple sutures (Figure 36.5). Particular care is taken at the transition from the septal horizontal mattress sutures to the interrupted simple sutures at the left side of the septal incision so as to ensure excellent hemostasis (Figure 36.6). Two additional horizontal mattress sutures are placed with the pledget on the right side of the ventricular septotomy and then through the

Mattress Suture
Figure 36.2. The incision in the aorta is extended ventricular wall away from the pulmonary valve.The across the annulus to the left of the right coronary septum is then incised and excised to open the left ostia and then aimed apically down the free right ventricular outflow tract.
Left Ventricule Suture
mTr

Figure 36.3. The aortic root is excised, leaving coronary buttons.

Mattress Leaflet
Figure 36.4. The septal defect is filled with the entire anterior leaflet of the mitral valve, fixed with pled-getted horizontal mattress sutures of 4-0 polypropylene monofilament.
Homograft Aortic Valve Replacement
Figure 36.5. Once the "annulus" is reached with the monofilament mattress sutures, the interrupted braided sutures are used as for simple root replacement.

Figure 36.6. Usually about 30-40 interrupted braided sutures are required for the proximal suture line.

Figure 36.6. Usually about 30-40 interrupted braided sutures are required for the proximal suture line.

Homograft Aortic Valve ReplacementPledget Felt Sutures
Figure 36.7. Additional sutures placed at both triangulation points are tied and then later used for the right ventriculotomy pericardial patch.

allograft; they are later passed through the pericardial patch closure of the right ventriculotomy and tied, which secures the triangulation points of the closure (Figure 36.7). All sutures are then sequentially tied, thereby positioning the allograft over the left ventricular outflow. The septal sutures are tied first (Figure 36.8).

Clarke recommended a running polypropylene suture technique and a double suture technique on the septal portion of the repair.1 We have not found that necessary and prefer the interrupted technique with multiple pledgetted sutures on the ventricular septum. The allograft mitral leaflet is sutured to the right side of the septum so that the "depth" of the septum contributes to enlargement of the left ventricular outflow tract.

The coronary sinuses are then excised from the allograft to accept the large buttons of the native coronary ostia. The allograft right coronary stump is suture-ligated, as it has been rotated 120° into the non-coronary sinus region. The coronary buttons are made large and usually slightly higher than would be anatomic in order to maintain length and stretch to avoid kinking. The buttons are sutured to the oval defects with running 5-0 monofilament sutures (Figures 36.9 and 36.10).

The left ventricular vent is shut off and the left ventricle gradually allowed to fill while the distal aortic suture line is constructed with running 4-0 monofilament suture. This suture line is buttressed with a strip of felt (Figure 36.11). Because the native curve of the allograft

Suturing Left Ventricule
Figure 36.8. After seating the allograft, the sutures are sequentially tied, beginning with the mattressed septal sutures. The simple interrupted sutures are buttressed with a strip of Teflon felt.

is in a direction reversed from normal, the distal allograft aorta is usually beveled posteriorly. It is also helpful to keep the allograft ascending aortic root relatively short, but of course the incision needs to be above the sinus ridge (Figure 36.12). Native supravalvular ascending aortic pathology must be excised.

The reconstruction is completed after de-airing the aortic root and removing the aortic cross-clamp. As in the Konno operation, the right ventricular free wall defect is repaired with a patch (Figure 36.13). Clarke recommended a piece of homograft. We have tended to use pericardium for this patch, suturing it to the defect with a running 4-0 or 5-0 polypropylene suture. The suturing along the annulus of the allograft is, of course, nontrans-

mural, and these sutures need to be carefully placed.

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