Fallot's Tetralogy | Ventricular Septal Patch | Pulmonic Augmentation & Valve Prosthesis (3/8)

This baby girl has Tetrology of Fallot, requiring surgical repair.

We have to stop the heart to repair the ventricular septal defect. Cardioplegia perfusate will be given to stop the heart in a relaxed state and to protect it while it is stopped. A purse string of braided suture is made around the intended cannulation site. The site in the ascending aorta is located just far enough away from the return cannula that an aortic crossclamp may be placed between the two cannulae. The purse string itself is placed such that the snugger is on the patient's left hand side. While the purse string is being placed the cardioplegia line is being primed offscreen.

The pulmonary trunk is drawn downwards this allows the ductus arteriosus to be ligated as high up as possible, as close as possible to the arch of the aorta. While the assistant steadies the ascending aorta, a cardioplegia cannula with stylet is introduced through the purse string into the intended site of cannulation. The purse string is taken around the foot of the cannula and then the snugger is tightened, securing the cannulation site. The stylet is removed, the cannula deaired and connected to the cardioplegia section of the cardiopulmonary bypass machine.

With pump flows momentarily reduced, an aortic crossclamp is placed between the return cannula and the cardioplegia cannula. Once the crossclamp is confirmed to be in position, it is closed and pump flows are returned to normal. Above the clamp, return flow from the cardiopulmonary bypass machine enters the distal ascending aorta and perfuses the rest of the patient's body. Below the crossclamp, cardioplegia perfusate fills the lower ascending aorta and enters the coronary arteries.

Some of the coronary circulation empties into the coronary sinus, causing the right atrium to distend. A right atriotomy is made and a slim pericardiotomy sucker is inserted through the atriotomy to empty out the right atrium. This drainage of blood from the coronary sinus into the right atrium continues for so long as cardioplegia perfusate is being given. The atriotomy is extended headward in the direction of the right atrial appendage. It is then extended downwards in the direction of the inferior cavoatrial junction. The slim pericardiotomy sucker in the right atrium is now redirected through a patent foramen ovale. The tip of the sucker is now in the left atrium, decompressing the left side of the heart.

The lower edge of the atriotomy is suspended with a silk stay suture. Then stay sutures are placed in each of two corners of the tricuspid valve. This patient has a perimembranous ventricular septal defect, which can be visualized behind the septal leaflet of the tricuspid valve. Slim Senning retractors are passed through the annulus of the tricuspid valve and used to elevate the right ventricular inflow tract. The tricuspid valve and the right ventricular lumen are inspected, as is the ventricular septal defect.

A ring towel is placed over the operative site to better organize sutures, then interrupted sutures are placed around the margin of the ventricular septal defect. Part of the rim of a perimembranous ventricular septal defect lies very close to the annulus of the tricuspid valve. Sutures in the region of the annulus of the tricuspid valve therefore must be passed from the atrial surface to the ventricular surface. These are the sutures for which the pericardial pledgets were harvested earlier.

The edges of the septal leaflet of the tricuspid valve are gently detached. This allows us to roll back the leaflet and expose the ventricular septal defect. Muscle overgrowth within the right ventricle is also resected. The right ventricular outflow tract is plumbed with dilators of various sizes to find any areas of narrowing that may lie low down in the right ventricle.

The rest of the suture are then placed around the margins of the ventricular septal defect. For that part of the margin of the septal defect that is located well within the right ventricle, the sutures are placed entirely within the right ventricle and have pledgets of wool felt.

A woven septal defect repair patch is cut to the correct size and shape and compared one final time before being mounted for suturing. The sutures placed earlier around the margin of the ventricular septal defect are taken up in turn and passed through the edge of the septal defect repair patch.

With all of the sutures in place the patch is lowered into position over the defect. Then the sutures are tied, securing the patch over the defect. The margins of the repair are then inspected and sometimes additional suturing is required.