Central Pulmonary Artery Reconstruction

In patients with pulmonary atresia and MAPCAs, except those with generous true pulmonary arteries and minor collateral contribution to pulmonary blood flow, it is almost always necessary to augment the central pulmonary arteries. In some cases, the anatomy of collaterals and true pulmonary arteries is conducive to reconstruction of the central pulmonary arteries without the need for nonautologous tissue. But in many cases, it is necessary to reconstruct the central pulmonary arteries using allograft tissue in order to augment the diameter of the left and right branch pulmonary arteries. A segment of pulmonary artery allograft can be fashioned as needed into a single patch that extends from hilum to hilum, as separate patches on the left and right or as a single unilateral patch (Figure 58.1). Sometimes we will use an extension of the right ventricular outflow tract valved allo-graft conduit for central pulmonary artery augmentation (see below), though there is generally inadequate length to extend such a patch to the hilum, especially on the right side. In the rare situation where there is insufficient pulmonary artery or collateral tissue to create hilum to hilum native tissue continuity, it may be necessary to reconstruct the central pulmonary arteries in their full circumference using an allograft tube (Figure 58.2). In such rare situations we have used nonvalved segments of pulmonary artery allograft. If an appropriately sized conduit is not available,

Figure 58.1. A large collateral to the right lung is filleted open and augmented with a patch of pulmonary allograft (hatched). Two smaller collaterals are anastomosed end-to-side to the augmented collateral, which is then anastomosed obliquely to the central right pulmonary artery. The small true pul-

Figure 58.1. A large collateral to the right lung is filleted open and augmented with a patch of pulmonary allograft (hatched). Two smaller collaterals are anastomosed end-to-side to the augmented collateral, which is then anastomosed obliquely to the central right pulmonary artery. The small true pul-

monary arteries are opened superiorly along most of their length, then augmented with a single patch of pulmonary allograft. A valved pulmonary or aortic allograft conduit is sewn end-to-end to the central pulmonary arteries for reconstruction of the right ventricular outflow tract.

a larger allograft can be downsized and extra tissue used for distal augmentation. As with distal reconstruction, we tend to use running 7-0 monofilament suture for central pulmonary artery repair, with absorbable suture in tissue to tissue anastomoses and non-absorbable suture when allograft tissue is being sewn.

Conduit reconstruction of the right ventricular outflow tract in pulmonary atresia with MAPCAs is essentially the same as for other lesions requiring right ventricle to pulmonary artery conduit repair. The primary difference is

Figure 58.2. Four tortuous collaterals to both lungs artery will be supplied through either a valved allo-are divided and sewn to a tube of pulmonary allo- graft conduit from the right ventricle or a systemic-graft. Blood flow to this unifocalized neo-pulmonary pulmonary artery shunt.

Figure 58.3. Moderate sized true pulmonary arteries are opened along their length. Collaterals to each lung are divided from their origin, opened longitudinally, and sewn side to side to the incision in the true left and right pulmonary arteries. A valved right ven-

tricle to pulmonary artery allograft conduit is attached to the unifocalized neo-pulmonary artery, with segments of allograft tissue extended out to augment both central branch pulmonary arteries.

Figure 58.3. Moderate sized true pulmonary arteries are opened along their length. Collaterals to each lung are divided from their origin, opened longitudinally, and sewn side to side to the incision in the true left and right pulmonary arteries. A valved right ven-

tricle to pulmonary artery allograft conduit is attached to the unifocalized neo-pulmonary artery, with segments of allograft tissue extended out to augment both central branch pulmonary arteries.

that the distal tissue of the allograft conduit may be employed extensively to augment the left and right pulmonary arteries (Figure 58.3). Also, because pulmonary arterial pressure may be anticipated to be somewhat higher in this lesion than in other defects that require right ventricular outflow tract reconstruction, we tend to utilize aortic valved conduits more often in this patient population.

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