Cardiac Tumors

BENIGN TUMORS

Myxoma

Primary tumors of the heart are very rare. More than half of the benign tumors are myxomas. Although they can occur in any chamber of the heart, most myxomas arise from the interatrial septum and are seen most commonly in the left atrium. In approximately 15% of patients, the tumor is located within the right atrium.

The diagnosis may be suggested by the patient’s symptoms, often related to obstruction of flow through the mitral orifice or systemic embolization. Echocardiography confirms the diagnosis.

Technique

The heart is exposed through a median sternotomy. The aorta is cannulated in the usual manner. The superior and inferior venae cavae are both directly cannulated (see Chapter 2). This is accomplished with great care to avoid manipulation of the atria.

Venous Cannulation through the Right Atrium

The introduction of large cannulas into the superior and inferior venae cavae through the right atrium may dislodge tumor fragments as well as clutter the operative field during tumor resection. Therefore, direct cannulation of both cavae is always preferred.

The aorta is clamped, and the heart is arrested with cold blood cardioplegia administered into the aortic root (see Chapter 3). Previously placed snares around both venae cavae are snugged down on the venous cannulas. An oblique incision is begun on the right superior pulmonary vein with a long-handled no. 15 blade. The opening is extended obliquely across the right atrial wall. Two small retractors are placed on the atriotomy edges to expose the right atrial cavity, interatrial septum, and any right atrial tumor that may exist (Fig. 12.1).

Right Atrial Myxoma

Myxomas occurring in the right atrium are usually bulky and may have a relatively wide base. The incision is now extended across the interatrial septum, encircling the base of the tumor with an approximately 5-to-8-mm margin of grossly normal septal wall. The tumor is excised and removed (Fig. 12.1).

Left Atrial Myxoma

Myxomas occurring in the left atrium are usually pedunculated and have a relatively small base attached to the septum. The septal incision is extended across the septum under direct vision, and the base of the tumor is excised, leaving a 5-to-8-mm margin of normal septal tissue (Fig. 12.2).

Artery to the Sinoatrial Node

The artery to the sinoatrial node traverses the atrial septum superiorly. Injury to this vessel may result in sick sinus syndrome. The base of a myxoma in this vicinity should be shaved off.