Aortic Valve Replacement via the Ross Procedure

Aortic valve replacement is a common surgical procedure that can be performed with a variety of materials including mechanical valves, bioprostheses, homografts, or a pulmonary autograft. Mechanical valves in children and young adults require lifelong anticoagulation which poses embolic and hemorrhagic risks. Homograft or autograft aortic valve replacement avoids anticoagulation requirements, while maintaining robust hemodynamic stability to support normal growth and development. This case examines a 9 year old male with intermittent chest pain and increasing exercise intolerance who was scheduled for permanent valve replacement via the Ross procedure. His history includes bicuspid aortic valve with severe stenosis and coarctation of the aorta. Previous interventions include balloon aortic valvuloplasty, surgical valvotomy, and end-to-end anastomosis repair of coarctation. Echocardiogram and CT angiogram demonstrated severe aortic stenosis following aortic valvotomy with moderate hypertrophy of the left ventricle. Surgical excision of the aortic valve was completed, and the neoaorta was constructed with the pulmonary autograft. For children with aortic valve disease, the Ross procedure continues to provide excellent long-term outcomes with some limitations that will be discussed.

Biscuspid aortic valve is the most common congenital heart defect, representing a prevalence of roughly 1% of the population (1). It occurs when two cusps of the aortic valve fuse and is often associated with a longitudinal ridge known as a raphe. This raphe marks the site of the absent commissure and can predispose to aortic regurgitation and aortic stenosis (1). Bicuspid aortic valve presents clinically with a spectrum ranging from asymptomatic to severe aortic pathologies that commonly occur with genetic syndromes (1). Diagnosis can be confirmed with transthoracic echocardiography which is also used for continued surveillance. Procedural management of children and adolescents with severe aortic stenosis or left ventricular systolic dysfunction begins with balloon valvuloplasty (1). Repair of the valve can be treated surgically via valvotomy or total valve replacement in severe cases.  Aortic valve replacement (AVR) in the pediatric population remains a challenge. In adults, AVR is commonly performed with mechanical valves or bioprosthetic valves. The former requires lifelong anticoagulation which may not suitable for children due to increased risk of embolic and hemorrhagic events (2). Anticoagulation may impact those who would like to participate in contact sports or women who wish to become pregnant. AVR with the Ross procedure utilizes the patient’s native pulmonary valve as an autograft to serve as the neoaorta. The aorta is divided and the bicuspid or stenotic valve excised, followed by mobilization of the coronary buttons. The pulmonary autograft is harvested and anastomosed to the annulus of the native aortic root. This can be reinforced with a Dacron ring if necessary (2). Anastomosis of the coronary buttons to the autograft is then completed. To rebuild the right ventricular outflow tract, a cryopreserved or decellularized homograft may be used as the conduit. A xenograft conduit may also be considered (2). The proximal anastomosis of the conduit to the right ventricle is performed. This is followed by distal anastomosis of the pulmonary autograft to the ascending aorta. Lastly, the surgeon completes anastomosis of the conduit to the branch pulmonary arteries. This report demonstrates a successful AVR in a nine year old male via the Ross operation.

The patient was brought to the operating room placed in a supine position where general anesthesia was induced. The patient was then prepped and draped in a normal sterile manner over the anterior chest. A 15-blade scalpel was used make a midline incision through his previous incision. The fat and fascia were divided with electrocautery and sternal wires were removed. The sternum was divided with oscillating saw. Retrosternal adhesions were taken down with electrocautery. A retractor was placed. We then mobilized the aorta, aortic arch, branch pulmonary arteries, superior and inferior vena cava, and right atrium. The patient was systemically heparinized. Cannulation sutures were placed in the aortic arch and the superior and inferior vena cava. These areas were cannulated with an 18 French in the aorta, a 24 French in the superior vena cava and 24 French in the inferior vena cava. Patient was commenced on cardiopulmonary bypass and cooled to 32°C. The aorta was cross-clamped, and 20 cc/kg of Del Nido cardioplegia was given antegrade. The heart was promptly arrested. We divided the aorta just above sinotubular junction. There was a lot of scarring from previous repair of the sinuses. The valve was bicuspid and immobile. We excised the valve. Next, we excised the coronary artery buttons, and these were mobilized with electrocautery. Then, the pulmonary artery was divided at the bifurcation. We examined the valve, and it was found to be excellent for translocation. The pulmonary valve was excised being sure not to injure any coronaries and the septum. The autograft was then sewn into the left ventricular outflow tract. This was performed in an orthotopic manner using a 5 0 Prolene suture in a running fashion. Next, sutures were placed in each of the commissures of the autograft. Arteriotomies were made corresponding to the each of the buttons. The anastomosis of the buttons to the arteriotomies was performed with 5 0 Prolene suture in running fashion. Next the homograft was brought to the table and was trimmed appropriately. The distal anastomosis with the branch pulmonary arteries was performed with a 5 0 Prolene suture in running fashion. The aorta was then reanastomosed with the autograft using a 5 0 Prolene suture in running fashion. We began rewarming at this point. COSEAL was applied over the entire area. The proximal anastomosis with the pulmonary homograft and the right ventricular outflow tract was performed with a 4 0 Prolene suture in running fashion. We vigorously de-aired the heart, and the cross-clamp was removed. The heart began to recover and achieved sinus rhythm. After proper warming, we separated from cardiopulmonary bypass with excellent hemodynamics and no inotropic support. We gave protamine decannulated. Chest tubes were placed to each of pleura in the anterior mediastinum. Ventricular wires were placed. The chest was then closed in layers. The sternum closed with interrupted wire. Fat and fascia were closed with Vicryl suture. Skin was closed with Monocryl and Dermabond was applied. Patient was returned to the intensive care unit after being extubated.

The patient was extubated in the OR and transferred to the CVICU. Postoperative transesophageal echocardiogram shows laminar flow in the neo-aorta with no residual aortic stenosis or regurgitation. His postoperative course was uneventful, and he was discharged on postoperative day six.

For children and adolescents with symptomatic bicuspid or stenotic aortic valve, AVR can be achieved with the Ross procedure. The crux of the operation involves harvesting the patient’s own pulmonary valve and translocating it to serve as the neoaorta. Anastomosis of the pulmonary autograft to the aortic annulus can be achieved with the subcoronary or root replacement technique (2). This case demonstrates the root replacement technique without use of a Dacron graft. Dacron grafts may be included to prophylactically address complications such as dilatation of the pulmonary autograft, though long-term data are not well established (2). A shorter Dacron ring may also be sutured between the autograft and the ascending aorta to provide more stability to the sinotubular junction (2). Additionally, the pulmonary autograft must be implanted deep within the left ventricular outflow tract for proper support of the graft within the annulus. When compared to mechanical AVR, the pulmonary autograft provides significant benefit for younger patients since it provides exceptional hemodynamic support and avoids long-term anticoagulation (1,2). It is also associated with increased quality of life compared to mechanical valves (2). However, a major downside is that mechanical AVR is associated with fewer re-interventions compared to homografts and bioprostheses (3). Another pitfall of the Ross procedure is potential failure of the pulmonary valve, resulting in pathology of two native valves rather than one. To ensure long-term stability after the procedure, the patient’s blood pressure must be strictly controlled for a minimum of 6-12 months which will allow proper autograft adaptation while minimizing dilatation on the neoaorta (2).

The authors declare that they have no relationships relevant to the contents of this research to disclose.

None.

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