The Ross Operation

Introduction

The idea of transferring the pulmonary valve to the aortic position combined with right ventricular outflow tract reconstruction was introduced by Ross and Summerville in 1966 [1226, 1482]. The operation is performed on hypothermic cardiopulmonary bypass with bicaval cannulation. Before cannulation, the ascending aorta and the pulmonary artery and its branches are extensively mobilized. Cardiopulmonary bypass is instituted, and if the decision to replace the aortic valve with a pulmonary autograft is made, then the pulmonary valve can be harvested before the aorta is clamped, so long as the aortic valve is competent. Otherwise, the aortic cross-clamp is applied and an oblique incision down to the non-coronary sinus is made, and cardioplegia is administered directly into the coronary orifices.

The main pulmonary artery is partially opened at its bifurcation into the branch pulmonary arteries, making sure to remain distal to the commissures of the pulmonary valve. The pulmonary valve is inspected through the arteriotomy in order to ensure that it appears and functions normally. If this is the case, then the arteriotomy is completed to completely transect the main pulmonary artery, this being done at the pulmonary bifurcation, safely distal to the commissures of the pulmonary valve. The base of pulmonary valve is next separated from the aortic root by electrocautery and sharp dissection, as indicated. A Dennis-Brown clamp is passed retrogradely through the pulmonary valve as a guide to locate the incision on the anterior aspect the right ventricular outflow tract, this being typically 3 or 4 mm beyond the lowest point of leaflet attachment. This incision is carried medially, taking the full thickness of the anterior wall of the right ventricle, and although usually safe, care must be taken to avoid injury to the conus branch of the right coronary artery. Posteriorly and to the left lie the left main coronary artery, the left anterior descending coronary artery, and the first septal branch which are all at risk of injury during this part of the dissection. Injury to these crucial structures is avoided by making an oblique incision deeper on the endocardial than the epicardial side. The endocardial incision is generally first made by sharp dissection from within the right ventricular outflow tract, with subsequent enucleation of the pulmonary valve completed with scissors angled so as to leave the epicardium intact.

The aorta and orifices of the coronary arteries are next prepared for a ‘mini-root’ replacement. The aorta is transected two to three centimeters distal to the orifices of the coronary arteries, just proximal to the aortic cross-clamp. The native aortic valve leaflets are completely excised, leaving the annular ring on which to later sew the pulmonary autograft. The coronary artery orifices are removed from the aortic root, and are partially mobilized in order to later ensure a tension-free coronary-to-autograft anastomosis.

Once the aortic root is prepared, the pulmonary autograft is inserted into the aortic position. The autograft is trimmed of all excessive muscle up to within 1 or 2 mm of the cusp insertions, and any loose tissue is removed from the pulmonary arterial wall. The proximal anastomosis is completed first, this being done on an entirely relaxed heart with a running non-absorbable suture. During insertion, the sinuses of the autograft are carefully matched to the aortic-root sinuses, as this will later ensure a tension-free coronary anastomosis. The left main coronary anastomosis is performed next. A slit is made into the pulmonary autograft sinus, and is enlarged as necessary. Care is taken not to injure the valve leaflets or the annulus of the autograft during preparation. The left main coronary artery orifice is sewn into place with a running suture of nonabsorbable suture. It is our practice that prior to anastomosing the right coronary artery, the distal aortic anastomosis is performed next, this being done with a running suture of non-absorbable suture. Once completed, the right coronary artery is grafted to the corresponding sinus on the pulmonary autograft, again with a running non-absorbable suture taking care not to injure the autograft valve leaflets or annulus.

Once the ‘mini-root’ is completed and de-aired, antegrade cardioplegia can be administered. Prior to this, a retrograde cannula is inserted into the coronary sinus under direct vision, and retrograde cardioplegic solution is administered every 20 - 30 minutes. The right ventricular to pulmonary artery homograft conduit is next inserted. We prefer a valved pulmonary homograft to reconstruct the right ventricular outflow tract, as these tend to calcify less quickly than an aortic homograft. The homograft is prepared in a manner analogous to the previously inserted autograft, with all excessive muscle being trimmed up to 1 or 2 mm of the cusp insertions. The distal anastomosis can be performed with the aortic cross-clamp removed, but is generally completed prior to this in order to maximize exposure. Once completed, the aortic cross-clamp is removed, and the proximal anastomosis is performed, thereby completing the repair.