Technical Aspects of the Ross Procedure

Abstract

Use of the autologous pulmonary valve for replacement of a diseased aortic valve (Ross procedure) was introduced in the late 1960s but has gained widespread use only in the last 10 to 15 years. Part of the reason for the delay in acceptance of this surgical procedure has been its perceived complexity. We describe herein the technical aspects of the Ross procedure as it is performed at our surgical service.

The use of the autologous pulmonary valve for replacement of a diseased aortic valve was introduced by Donald Ross of the United Kingdom in 1967. ¹ The procedure was developed on the basis of prior experimental work with autologous canine pulmonary valve transplantation by Shumway and colleagues. ^2,3 As of Spring 2001, the International Registry for the Ross Procedure, maintained by Dr. Jim Oury, had registered 242 surgeons from 126 institutions who had performed a total of 4,822 Ross procedures. We have previously described the indications for and current status of the Ross procedure; ⁴ herein, we focus on the technical aspects of the procedure.

Technical Aspects

We begin our approach to the Ross procedure with standard bicaval and distal ascending aortic cannulation. We use antegrade and retrograde cold blood potassium to achieve cardioplegia. After we have placed the patient on cardiopulmonary bypass and stopped the heart, we transect the ascending aorta in a transverse plane 1 cm distal to the origin of the right coronary artery. This allows us to inspect the aortic valve, aortic root, and left ventricular outflow tract to determine their suitability for this procedure. The next step is to transect the main pulmonary artery in a transverse plane just proximal to its bifurcation, which allows inspection of the pulmonary valve for anomalies that would prevent its use as the new aortic valve (Fig. 1).

Fig. 1 Transection of the ascending aorta and the main pulmonary artery in a transverse plane.

If the decision is made to proceed with the Ross procedure, the type of valve replacement must be determined; it can be subcoronary, subcoronary with retained noncoronary sinus, cylinder, or full root (Fig. 2). The full root technique is used on our service and in about 90% of the cases reported to the Ross Registry, and it is the procedure described here.

Fig. 2 Four possible types of valve replacement for the Ross procedure.

The pulmonary artery root is retracted toward the ceiling (a lung clamp is a good atraumatic grasper for this), and the posterior pulmonary artery root is sharply dissected straight downward until muscle of the right ventricular outflow tract is visible. Care must be taken to avoid the left main coronary artery as it passes behind the pulmonary artery root. The pulmonary artery is also sharply dissected from the aortic root at this point, where it may be densely adherent. Since the aortic root is to be replaced, one should err toward the aorta and take care not to injure the pulmonary artery (Fig. 3). A right-angled clamp is passed through the pulmonary artery and the pulmonary valve to mark a spot 1 cm proximal to the lowest point of the pulmonary valve. An opening is sharply made into the right ventricular outflow tract (Fig. 4). The anterior right ventricular wall is then divided, with the scissors kept 5 to 10 mm proximal to the pulmonary valve. The posterior muscle is scored with the knife and divided through part of its thickness (a change in the direction of the muscle fibers can often be seen).

Fig. 3 Dissection separating the pulmonary artery from the left coronary artery.

Fig. 4 Insertion of an angled clamp through the pulmonary artery to an opening 1 cm below the pulmonary valve.

The scissors are now used for dissection, parallel to the floor, to completely excise the pulmonary artery root. This change in direction helps avoid the 1st septal perforator artery. Care must be taken to stay relatively close to the pulmonary valve in order to avoid the left anterior descending coronary artery (Fig. 5). The pulmonary root is then stored in the pericardial well to the right of the heart. We now begin to thaw the pulmonary valve allograft that we will use to reconstruct the pulmonary root. The right ventricular outflow tract will accommodate virtually any size pulmonary valve if the patient is beyond childhood. We therefore choose the largest pulmonary valve allograft, close to the patient's age, that is available.

Fig. 5 Complete excision of the pulmonary root. Inset: The ventricular septum is divided below the pulmonary valve leaflet.

The aortic valve and root are excised, at which time buttons of aortic wall are left on the main coronary arteries, about 5 to 10 mm from the ostia to the outer edge. As in all aortic valve surgery, complete decalcification of the aortic valve annulus is essential. The proximal suture line for the anastomosis between the pulmonary valve autograft and the left ventricular outflow tract may be accomplished as a running or interrupted suture. We prefer an interrupted 4–0 polypropylene suture line with a strip of pericardium tied between the sutures as a buttress (Fig. 6). Before placing the proximal suture line, we mark each commissure with a small suture of 4–0 polypropylene and use these sutures as guides for reimplanting the coronary arteries. The left main coronary artery reimplantation site is chosen first, in the new left cusp. This artery is usually easy to place, because the root is still open and the valve cusp is easily seen. We make an incision with a #11 blade and use a 4.8-mm punch to create a symmetric opening. The left main coronary artery anastomosis is then made with a running 5–0 or 6–0 polypropylene suture. At this point, some surgeons prefer to complete the distal suture line and distend the new aortic root in order to choose the placement site of the right coronary artery and avoid kinking. We usually implant the right coronary artery before we complete the distal suture line, but make a point of pulling it high onto the new right cusp. This anastomosis is also made with a running 5–0 or 6–0 polypropylene suture. We can see both anastomoses through the open root; thus, we can ascertain that the new aortic valve cusps have not been injured during coronary artery reimplantation.

Fig. 6 Anastomosis of the pulmonary autograft to the left ventricular outflow tract, accomplished with interrupted 4–0 polypropylene sutures and a strip of pericardium between the sutures as a buttress.

We then place the antegrade cardioplegic cannula within the open end of the new aortic root and pinch it off digitally while antegrade blood cardioplegia is given. This technique allows us to check for leaks at the coronary artery anastomosis site and for hemostasis in the pulmonary valve harvest bed. Retrograde blood cardioplegia is now administered, and we again check the pulmonary valve harvest bed. Complete hemostasis is important at this point, because the area behind the pulmonary valve will not be visible after implantation of the pulmonary valve allograft to reconstruct the pulmonary root.

By now, the pulmonary valve allograft should be thawed and ready for use. We complete the proximal suture line with a running 4–0 polypropylene suture. The posterior portion of the suture line must be kept shallow to avoid damage to the 1st septal perforator artery. Care should also be taken at the outside border to avoid placement of excessively deep sutures into the right ventricular outflow tract and possible damage to the left anterior descending coronary artery. We often place an interrupted pledgeted suture at this site to ensure hemostasis. The distal suture line is completed with a running 4–0 polypropylene suture (Fig. 7). We routinely use transesophageal echocardiography to evaluate valve function before we leave the operating room.

Fig. 7 Completion of proximal pulmonary artery allograft with running 4–0 polypropylene suture. Inset: Shallow sutures on the posterior wall of the proximal pulmonary-artery allograft anastomosis are used to avoid the 1st septal perforator.

We conclude that the Ross procedure, despite its perceived complexity, can be done with excellent results if careful attention is paid to the technical details of the procedure.