Although primary tumors of the heart are rare,
myxomas are the most frequent benign primary heart tumors, which account for 0.3% of open heart surgery
worldwide. The clinical presentation in the majority
of the patients includes significant hemodynamic
symptoms related to the blood flow obstruction and embolic phenomena. Cardiac myxomas can be
challenging to diagnose, due to their rare occurrence
and varying clinical presentation. The mean age
was 37.1 years at the time of diagnosis in our study, which is significantly lower than in most Western
countries where the mean age is 50 to 55 years.[
5-
7] In
addition, dyspnea was the most common symptom
in our patients as the obstructive pathology. Patients
may also present with cyanosis and cerebral hypoxia
produced by right-to-left shunting secondary to the right ventricular inflow obstruction caused
by a huge right atrial myxoma associated with
patent foramen ovale or ASD, as in one of our
patients. A higher risk of embolization has been
also reported and events occur in 30 to 45% of the
patients.[
5-
10] In our series, the embolization was less frequent than the Western series. In our series a total
of 14 patients developed embolization preoperatively
and three patients developed tumor embolization
postoperatively. Of 14 patients, 12 patients had
central nervous system (CNS) embolization and
one each had peripheral arterial and coronary artery
embolization. Of three patients with postoperative
tumor embolization, two developed in the early
postoperative period and one patient developed in
the late postoperative period. All these patients
had CNS embolization. Anemia and elevated ESR
are non-specific markers of several diseases and are
significantly more common in our study. The presence
of systemic symptoms was positively correlated with
elevated ESR. Systemic symptoms, anemia, and
elevated ESR could be due to the systemic effects of
interlukin-6, the cytokine implanted in generating a
generalized inflammatory response in patients with
myxomas. There were also elevated serum globulin
levels in all patients with reversal of albuminglobulin
ratio in our series.
Echocardiography is currently the most main
diagnostic modality available for imaging cardiac
tumors. It is non-invasive and allows a preoperative
diagnosis with accuracy and can quantitate the tumor
size, shape, attachment, and mobility.[11,12] It can also
screen the other chambers of the heart for additional
tumors. In addition, transesophageal echocardiography
has an increased sensitivity and specificity for
the diagnosis, particularly in patients with poor
transthoracic echo window.[11,12] In our series, the
two-dimensional transthoracic and transesophageal
echocardiography were successful primary tools for
the diagnosis of cardiac tumors. Magnetic resonance
imaging (MRI) and CT are not the first-line diagnostic
tools for myxomas, although more and more cases are
diagnosed by these technologies. These modalities are
helpful to detect benign and malignant tumors, when
transthoracic and transesophageal echocardiography
offer limited tissue characterization and confident
distinction between thrombi.[11-14] In addition, prolapse
through the mitral valve orifice on CT is a reliable
discriminative finding indicating a myxoma,[11-14] while
the absence of both first-pass and delayed contrast
enhancement on MRI is suggestive of a thrombus.[11-14]
Cardiac CT is also useful to detect metastases in
suspected malignancies, particularly when coupled
with 18 F-fluorodeoxyglucose (FDG) positron
emission tomography (PET). However, if a mass has
a typical echocardiographic appearance and is located as a left atrial myxoma, additional images with CT
or MRI are unnecessary. Surgical excision is the
treatment and must be undertaken immediately to
avoid the complications, such as systemic embolization
and valvular obstruction or incompetence.
The first successful surgery of a myxoma was
performed by Crafoord in Stockholm, Sweden in
1955, on cardiopulmonary bypass.[1-19] Since then,
many approaches have been described in the literature,
such as left atriotomy, right atriotomy and biatrial
approach.[11-19] In our series, the approaches used for
left atrial myxomas are left atriotomy in 73.6% (n=145),
right atriotomy in 13.7% (n=27), and biatrial approach
in 12.7% patients (n=25). Based on our findings, we
found that the left atriotomy approach was much
more convenient, simple, rapid, and safe approach
for the excision of the left atrial myxomas. The right
atriotomy approach was used for dumbbell-shaped
left atrial myxomas. The biatrial approach was used
in large and unusually located left atrial myxomas.
The right atrial myxoma was approached through
right atriotomy, while other types of myxoma were
approached either through right atrium and pulmonary
artery for the right ventricular outflow tract myxomas
and left atriotomy and transaortic approach for the
left ventricular myxomas. A wide excision with direct
closure of the defect was also done in 58.4%, pericardial
patch closure of the defect in 28.9%, excision and
fulguration of the raw area in 11.7%, and the use of
a Dacron patch in 1% patients of left atrial myxomas.
For the right atrial myxoma excision, a pericardial
patch was used in 85.2% patients and excision with
fulguration was done in 14.8% patients. Myxomas
attached to the chamber wall apart from the interatrial
septum, such as the right ventricular septum, left
ventricular apex, and tricuspid valve annulus require
wide excision alone or excision with fulguration.
Myxomas attached to the pulmonary valve require
excision of the valve leaflet, while those attached to
the posterior mitral leaflet can be excised with the
quadrangular resection of the leaflet with myxoma,
followed by prosthetic ring annuloplasty. Myxomas
attached to the anterior mitral leaflet require treatment
according to the involvement of the leaflet area. If a
small portion of the leaflet is involved, myxoma can
be shaved off the leaflet, or a small portion of the
leaflet can be excised, and the defect can be repaired
with an autologous pericardial patch. However, if the
major portion of the leaflet is involved, it may require
mitral valve replacement. To prevent recurrence, there is a consensus that surgical excision must include a
substantial portion of the normal endocardium near
the base of implantation.[16-19] Recurrence can be due
to inadequate resection, intraoperative implantation,
embolization or multi-centric growth.[5,6] In our series,
the recurrence rate was 3.1%, which is comparable to
the international standard of 5%.[16,17,19] The recurrence
was mainly found in left atrial myxomas, excised
through right atriotomy approach, probably due to
inadequate excision or intraoperative implantation.
In one case of multiple myxomas, recurrence was
seen at a different location, probably due to the
multi-centric growth. There were also three early
mortalities in our entire series, due to acute severe
left ventricular dysfunction and multi-organ failure,
probably secondary to coronary embolism. There was
no late mortality or pulmonary embolism.
In conclusion, cardiac myxomas are the most
common benign cardiac tumors in adults and the
left atrium is the commonest chamber involved.
Transthoracic and transesophageal echocardiography
is the optimal diagnostic modalities for myxomas. The
diagnosis of a cardiac myxoma is an indication for an
urgent surgery, due to the high risk of sudden death from
a thromboembolism or valvular obstruction. Therefore,
we recommend the left atriotomy approach for the
left atrial myxoma excision in view of convenience,
simplicity, and safety and right atriotomy approach
for dumbbell-shaped and right atrial myxomas. The
biatrial approach can be used in large and unusually
located left atrial myxomas, while individualized
approaches can be used for the treatment of for other
types of myxoma. To prevent recurrence, the surgical
excision must include a substantial portion of the
normal endocardium near the base of implantation.
The early mortality is most commonly due to coronary
embolism and the late postoperative survival is usually
excellent.
Declaration of conflicting interests
The authors declared no conflicts of interest with respect
to the authorship and/or publication of this article.
Funding
The authors received no financial support for the research
and/or authorship of this article.