Myxoma is the most common primary cardiac tumor, which frequently occurs in middle age and is more common in women than in men [2–5]. In our data, the mean age of the patients was 54.7 years at the time of surgery, and 86% were aged over 40 years. In addition, myxoma was 2 times more common in women than in men.
Myxomas vary in size, but the growth rate is difficult to document because they are usually removed after diagnosis [6–9]. However, in our study, the one patient who underwent surgery 15 months after initial diagnosis showed a rapid growth rate of 0.41 cm/month.
Although operative mortality is reported to be within 5%, the rate is increased with myxoma occurring in the ventricle [3, 5, 10, 11]. In our data, in-hospital mortality occurred in three patients. One patient died from low cardiac output syndrome after extensive resection of the left ventricle, while the other two patients died from pneumonia or coronary sinus rupture, which may occur after cardiac surgery. Pneumonia after cardiac surgery is one of the most common causes of postoperative mortality, and coronary sinus rupture during retrograde cardioplegia infusion is also a possible complication during cardiac surgery. These complications may occur due to the nature of cardiac surgery rather than myxoma itself. Although myxoma resection is relatively simple compared with other cardiac surgeries, it does require cardiopulmonary bypass during cardiac arrest. Therefore, postoperative complications may occur as in other more complex cardiac surgeries, and should be recognized.
Regarding the surgical approach, a biatrial approach is helpful to determine the correct resection margin by confirming the tumor pedicle under direct visualization, to minimize manipulation of the tumor, to find hidden myxomas by inspection of all heart chambers, and to secure the septal defect after resection of a tumor located on the atrial septum . On the other hand, a transseptal approach through right atriotomy may provide adequate mass exposure and, as a result, low recurrence and easy repair of a single incision on the right atrium . However, if the myxoma is sessile, has a broad base, and is attached to the atrial septum, a biatrial approach, rather than a transseptal approach, may reduce the risk of injury and tumor emboli. Even though a transseptal approach is simpler than a biatrial approach, it is only useful when the myxoma is pedunculated and has a narrow stalk. We primarily used biatrial incisions, but, a transseptal approach or left atriotomy only was used for resection of small myxomas confirmed on preoperative 2D echocardiography. Our institution does not have a guideline regarding the incision site as it relates to tumor size. However, if the largest tumor is less than 2 ~ 3 cm in size, wherein the tumor fully can be removed through a transseptal incision without breaking, the base of the stalk is narrow, and the motion of the tumor is active according to the heart beat on 2D echocardiography, we use a transseptal approach. In all other cases, a left atriotomy should be performed first. The position and shape of the tumor is evaluated, and, if the tumor can be removed without manipulation, it is removed without an additional incision. If the stalk is short or of a sessile form, we perform an additional right atriotomy to secure the resection margin. Because all tumors can be detected on preoperative transthoracic echocardiography due to advances in imaging techniques, and additional intracardiac evaluation is performed during surgery using transesophageal echocardiography, especially when left atriotomy only is performed, additional cardiac incisions for evaluation of all cardiac chambers may not be necessary.
The recurrence rate after myxoma resection has been reported to be less than 5% [3–5, 12]. In our data, two patients (2.1%) had recurrence. One patient had multiple myxomas and underwent a reoperation. The other patient was suspected to have recurrence on the atrial septum, but it was not confirmed histologically. Because we could not rule out myxoma completely, we regarded it as recurrence on the previously resected margin. Myxoma recurrence is caused by incomplete resection or tumor seeding during mass manipulation . Our two cases of recurrence were thought to be caused by incomplete primary resection because they were located on the resection margin. Therefore, some authors insist on wide resection to prevent recurrence following incomplete resection . However, other reports claim that simple tumor resection is sufficient because of the low recurrence rate [4, 16]. Our recurred patients underwent full-layer resection including the stalk and primary closure, and no patient who underwent only simple myxoma resection without defect repair was recurred. Therefore, it is thought that all myxoma patients are not necessary taken full-layer resection. However, in cases of myxoma occurring at a relatively young age, with ventricular origin, family history, Carney complex, or multiple myxomas, full-layer wide resection is recommended because of the increased recurrence rate [3, 5, 12, 17].
Our study has several limitations. First, this was a retrospective study. However, this study design was inevitable because cardiac tumors are extremely rare and early surgical resection is the treatment of choice. Second, we estimated mortality as total death without considering cardiac or sudden death separately. Although this does not reflect disease-related mortality specifically, it is thought that total death lowers selection bias.