*6.3.1.1 Previous transannular patch*

The most common scenario occurs with a dilated right ventricular outflow tract from the previous repair of tetralogy of Fallot with a transannular patch (**Figure 8A–D**). In the setting, the patch is opened longitudinally and stay sutures are placed on both sides. Most commonly, the incision is extended proximally into the RVOT and distally into the proximal left main branch pulmonary artery. Pathological/remnant pulmonary valve cusps are resected if present. An appropriately sized bovine pericardial patch (our preference) is then chosen and sewn distally to the proximal left main branch pulmonary artery. It is not uncommon that concomitant branch pulmonary arterioplasty is needed in these cases. The patch is sewn in with running polypropylene sutures till the proposed level of the new pulmonary prosthesis is reached.

An appropriately sized prosthesis (biological/mechanical) is chosen and is secured along the native pulmonary annulus posteriorly with running polypropylene suture (interrupted sutures with or without pledgets may be used sometimes based on the tissue quality). It is critical to avoid deep sutures along the pulmonary annulus due to the close proximity of the left main coronary artery.

### **Figure 8.**

*Intraoperative photos showing the most commonly used technique for pulmonary valve replacement. (A) A longitudinal incision is created along the main pulmonary artery and is extended proximally into the right ventricular outflow tract and distally usually to the proximal left main pulmonary artery. A large pericardial patch is then sued to augment the main pulmonary artery is extended down to the level of the future prosthesis, (B) the prosthesis is secured with a running polypropylene suture along the posterior annulus, (C) the anterior portion of the sewing ring is then secured to the undersurface of the pericardial patch, (D) the remainder of the patch is trimmed and used to complete the right ventricular outflow tract reconstruction. RV: right ventricle.*

In fact, in some situations, it is better to place the prosthesis more distally (between the native pulmonary annulus and the pulmonary artery bifurcation) to avoid compromising the left coronary artery. The anterior portion of the sewing ring of the prosthesis is then secured to the undersurface of the patch with a running suture. It is important to carefully think about the orientation of the prosthesis before securing it to the undersurface of the patch and especially when it is a biological one due to its larger profile that can create a higher gradient across its path if not oriented properly. The prosthesis should be tilted posteriorly toward the pulmonary bifurcation. Also, it is important to have some redundancy in the pericardial patch proximal and distal to the prosthesis to ensure no gradient is created due to a tight patch. This completes the prosthesis securement in the outflow tract. The rest of the bovine pericardial patch is then trimmed and sewn to the RVOT to complete its reconstruction.
