Clinical Investigation Surgical Treatment of Atrial Myxomas A Report of 20 Cases Bum Koo Cho, MD Doo Yun Lee, MD A. Thomas Pezzella, MD Sung Nok Hong, MD Pill Whoon Hong, MD Key words: Myxoma; heart, neoplasms; heart, atrium; aortocoronary bypass; echocardiography From: The Department of Thoracic and Cardiovascular Surgery, College of Medi- cine, Yonsei University, Seoul, Korea Dr. Pezzella was a Visiting Professor in the Division of Cardiothoracic Surgery at Yonsei University during April of 1988, on leave from the Department of Surgery at the University of Massachusetts Medical Center, Worcester, Massachusetts. Address for reprints: A. Thomas Pezzella, MD, Department of Surgery, University of Massachusetts Medical Center, Worcester, MA 01655 Twenty atrial myxomas were resected in 20 patients with the use of cardiopulmonary bypass, from the beginning of July 1966 through the end of June 1985, at Severance Hospital, Seoul, Korea. Nineteen patients had left atrial myxomas; 1 had a right atrial myxoma. Left atrial myxomas arose from the intra-atrial septum in 17 patients and from the leftatrialappendage in 2patients. The rightatrialmyxoma arose from the fossa ovalis. The 13 female and 7 male patients ranged in age from 14 to 63 years. Symptoms most often reported on presentation were those associated with mitral valve obstruction; other symptoms were associated with systemic embolization. The 1st 4 patients were tested with angiocardiography alone, and 3 of these were misdiagnosed. The last 16 were testedbyangiocardiography, M-mode echocardiography, and2-dimensional echocardiography, alone or in various combinations, and there were no further misdiagnoses. In our experience, 2-dimensional echocardiography was the most accurate method of diagnosing cardiac tumors. In 19patients, surgicalapproach was through a median sternotomy; in the 20th patient, approach was through a left thoracotomy, due to a preoperative misdiagnosis of mitral stenosis. No intraoperative embolizations ordeaths occurred. On follow-up of 17patients duringperiods ranging from 6months to 6 years, we hadno late deaths, andonly2patients suffered late complications: 1 had sudden right hemiparesis caused by an embolus 4 months aftersurgery (this improved upon conservative treatment); and 1 hada recurrence of tumor 3 years after surgery (the new myxoma was successfully resected). We conclude thatpatients who have undergone complete excision of benign myxomas nowhave an excellentprognosis, with minimal risk of intraoperative embolization and late recurrence. We conclude also that 2-dimensional echocardiography is an extremely accurate tool both in early diagnosis of intracardiac myxomas and in late follow-up after resection. (Texas Heart Institute Journal 1989;16:81-6) B efore 1960, cardiac myxomas were commonly diagnosed as chronic rheumatic heart disease, because of their ability to mimic mitral stenosis.1 Not only have we seen dramatic improvements in diagnostic methods26 since that time, but for more than 30 years7 surgery has offered a cure. Now, diagnosis and treatment have minimized the risks of potentially catastrophic complication so long associated with intracardiac myxoma-most specifically, those of preoperative atrioventricular dysfunction and intraoperative embolization. Diagnosis must be rapid and correct, however, and resection must be careful and complete, accompanied by thorough removal of all tumor fragments. This report examines 20 patients in retrospection, with emphasis on the evolution at our institution of surgical-but more especially of diagnostic-techniques for the recognition and treatment of atrial myxomas. Patients and Methods From the beginning of July 1966 through the end of June 1985, 20 patients underwent surgical resection of an atrial myxoma in Severance Hospital, Seoul, Korea. The 13 female patients (age range, 20 to 63 years) and 7 male patients (age range, 14 to 49 years) had 19 left atrial myxomas and 1 right atrial myxoma. Distribution by age and sex is shown in Table I, while chief complaints upon presentation are listed in Table II. Surgical Treatment of Atrial Myxomas 81 Texas Heart Instituteioumal
Surgical Treatment of Atrial Myxomas
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of Atrial Myxomas A Report of 20 Cases
Bum Koo Cho, MD Doo Yun Lee, MD A. Thomas Pezzella, MD Sung Nok Hong, MD Pill Whoon Hong, MD
Key words: Myxoma; heart, neoplasms; heart, atrium; aortocoronary bypass; echocardiography
From: The Department of Thoracic and Cardiovascular Surgery, College of Medi- cine, Yonsei University, Seoul, Korea
Dr. Pezzella was a Visiting Professor in the Division of Cardiothoracic Surgery at Yonsei University during April of 1988, on leave from the Department of Surgery at the University of Massachusetts Medical Center, Worcester, Massachusetts.
Address for reprints: A. Thomas Pezzella, MD, Department of Surgery, University of Massachusetts Medical Center, Worcester, MA 01655
Twenty atrial myxomas were resected in 20 patients with the use of cardiopulmonary bypass, from the beginning of July 1966 through the end of June 1985, at Severance Hospital, Seoul, Korea. Nineteen patients had left atrial myxomas; 1 had a right atrial myxoma. Left atrial myxomas arose from the intra-atrial septum in 17 patients and from the leftatrialappendage in 2patients. The rightatrialmyxoma arose from the fossa ovalis. The 13 female and 7 male patients ranged in age from 14 to 63 years. Symptoms most often reported on presentation were those associated with mitral valve obstruction; other symptoms were associated with systemic embolization.
The 1st 4 patients were tested with angiocardiography alone, and 3 of these were misdiagnosed. The last 16 were testedbyangiocardiography, M-mode echocardiography, and2-dimensional echocardiography, alone or in various combinations, and there were no further misdiagnoses. In our experience, 2-dimensional echocardiography was the most accurate method of diagnosing cardiac tumors.
In 19patients, surgicalapproach was through a median sternotomy; in the 20th patient, approach was through a left thoracotomy, due to a preoperative misdiagnosis of mitral stenosis. No intraoperative embolizations ordeaths occurred. On follow-up of 17patients duringperiods ranging from 6months to 6 years, we hadno late deaths, andonly2patients suffered late complications: 1 had sudden right hemiparesis caused by an embolus 4 months aftersurgery (this improved upon conservative treatment); and 1 hada recurrence of tumor 3 years after surgery (the new myxoma was successfully resected). We conclude thatpatients who have undergone complete excision ofbenign myxomas
nowhave an excellentprognosis, with minimal risk ofintraoperative embolization and late recurrence. We conclude also that 2-dimensional echocardiography is an extremely accurate tool both in early diagnosis of intracardiac myxomas and in late follow-up after resection. (Texas Heart Institute Journal 1989;16:81-6)
B efore 1960, cardiac myxomas were commonly diagnosed as chronic rheumatic heart disease, because of their ability to mimic mitral stenosis.1 Not only have we seen dramatic improvements in diagnostic methods26
since that time, but for more than 30 years7 surgery has offered a cure. Now, diagnosis and treatment have minimized the risks of potentially catastrophic complication so long associated with intracardiac myxoma-most specifically, those of preoperative atrioventricular dysfunction and intraoperative embolization.
Diagnosis must be rapid and correct, however, and resection must be careful and complete, accompanied by thorough removal of all tumor fragments. This report examines 20 patients in retrospection, with emphasis on the evolution at our institution of surgical-but more especially of diagnostic-techniques for the recognition and treatment of atrial myxomas.
Patients and Methods
From the beginning of July 1966 through the end of June 1985, 20 patients underwent surgical resection of an atrial myxoma in Severance Hospital, Seoul, Korea. The 13 female patients (age range, 20 to 63 years) and 7 male patients (age range, 14 to 49 years) had 19 left atrial myxomas and 1 right atrial myxoma. Distribution by age and sex is shown in Table I, while chief complaints upon presentation are listed in Table II.
Surgical Treatment of Atrial Myxomas 81Texas Heart Instituteioumal
Diagnostic Techniques Cardiac catheterization and angiocardiography, M- mode echocardiography, and 2-dimensional echocar- cliography wvere used separately or in combination for diagnosis (Fig. 1). Of the 20 patients, 8 had angio- carcliographic catheterization and 16 had M-mode echlocardiography. Four of these patients underwent both catheterization and M-mode echocardiography, and the last 10 underwent 2-dimensional echocardi- ography in addition to M-mode echocardiography.
Angiocardiography (8)
2-dimensional Echocardiography
M-mode Echocardiography
Fig. 1 Distribution of diagnostic procedures used in 20 cases
of atrial myxoma, from the beginning of July 1966 through the end of June 1985.
In the 4 patients who had both diagnostic catheteri- zation and M-mode echocardiography, the echocar- diographic results were considered diagnostic. The 2 patients who received only M-mode echocardiogra- phy (see Fig. 1) were diagnosed without supplemen- tal radiography; and the 10 patients who received both M-mode and 2-dimensional echocardiography were diagnosed after evaluation of both results, with the 2-dimensional echocardiograms accepted as definitive.
Diagnostic Findings Of the 4 patients who had catheterization alone, 3 were misdiagnosed preoperatively as having mitral regurgitation secondary to mitral stenosis, while 1 was diagnosed correctly as having mitral regurgita- tion secondary to an intra-atrial mass. All other diagnoses, made with the assistance of echocardi- ography, proved accurate. Nineteen ofthe 20 patients proved to have left atrial myxoma, correctly diag- nosed preoperatively, except for the 3 misdiagnoses of mitral stenosis. One patient had right atrial myxoma, and this was diagnosed correctly by echocardiogra- phy. Other findings were made only upon operation.
Surgical Findings The sites to which the stalks of the atrial myxomas were attached are summarized in Table III: most commonly, attachment was to the fossa ovalis, and with 2 exceptions (attachments to the atrial append- age) the other neoplasms also involved the interatrial septum. Diameters of the atrial myxomas, measured
TABLE 1. Age and Sex Distribution of 20 Patients with Atrial Myxoma
Age Male Female Total
50-59 - 2 2 60-69 - 2 2
7 13 20
TABLE II. Chief Complaints upon Presentation, in 20 Patients with Atrial Myxoma
No. of Chief Complaint Occurrences
Dyspnea on exertion 14
Syncope 2 Weakness of right arm 1
Cough 1 Anorexia 1
Site No. of Cases
Left atrial septum (through to the fossa ovalis) 1 2 Left atrial septum (not fossa ovalis) 5 Left atrial appendage* 2
Fossa ovalis in right atrium 1
20
* The recurrent myxoma (arising from 1 patient's left atrial appendage) is not included in this summary.
TABLE IV. Surgical Findings
Left atrial myxoma 16 Left atrial myxoma and mitral regurgitation 2
Left atrial myxoma and atrial septal defect 1
Right atrial myxoma and patent foramen ovale 1
82 Surgical Treatment of Atrial Myxomas V'olume 16, N'timber 2, 1989
laterally and discounting pedicles, ranged from 4 cm to 10 cm. Associated surgical findings (Table IV) in the left atrial myxoma group included mitral regurgi- tation (2 cases) and atrial septal defect (1 case). The patient with a right atrial myxoma was found also to have a patent foramen ovale. In our series, there were no instances of myxomas in 2 or more cardiac cavities.
Surgical Technique In 19 patients, the atrial myxomas were excised through a median sternotomy, under cardiopulmo- nary bypass. In the remaining patient-whose pre- operative diagnosis had been severe mitral stenosis with mild mitral regurgitation, and forwhom a closed mitral commissurotomy had been planned-approach was through a left thoracotomy; subsequently, a left atrial mass was discovered by index-finger palpation, and excised under cardiopulmonary bypass.
In all cases, cardiac arrest was achieved with topical hypothermia, and-from 1978 on-with the adjunct of cold potassium cardioplegia. Typically, a left atrial incision was made posterior to the interatrial groove. The attachment point of the tumor was then revealed through gentle manual exposure of the atrium, with care taken to avoid touching the pedicle or its attachment point. Before resection, the other 4 cardiac chambers were explored for the occasional multicentric tumor. The pedicle was then excised completely, along with a cuff of the tissue to which it was attached (usually the interatrial septum). To minimize the risk of embolization, great care was taken to handle the pedicle gently, and to remove any residual tumor debris from the surgical field.
The surgically created septal defect was closed by the following methods: in 10 instances, by direct suture alone, with running monofilament; in 8 in- stances, by prosthetic patch; and in 2 instances, by both direct suture and patch placement. Two patients required mitral valve replacement in addition to myxoma resection. In 1 of them, the mitral valve was not replaced until the day following initial surgery, when it became evident that severe preoperative mitral regurgitation had not abated. In the 1 instance of patent foramen ovale, the shunt was closed with direct suture.
The 2 patients whose myxomas arose from the atrial appendage did not require septostomy.
Gross and Microscopic Laboratory Findings The myxomas in our series consisted, upon gross observation, of a soft gelatinous tissue covered by a thin, glistening endothelial layer. On histologic ex- amination, the tumors were found to be benign and to comprise myxoma cells, endothelial cells, macro- phages, and a variety of intermediate forms, all within
a polysaccharide-rich ground substance. Numerous small blood vessels coursed through these tumors. and many ofthe macrophages were laden with hemo- siderin.
Results
Postoperative follow-up from 6 months to 6 years in duration was achieved in the cases of 17 patients. 15 of whom recovered with no postoperative complica- tions and remained in excellent condition.
Of the remaining 2 patients, 1 experienced sudden right hemiparesis 4 months after surgery, possibly caused by embolization of tumor debris; but the patient improved steadily with conservative treat- ment. A 2-dimensional echocardiogram was negative for residual or recurrent tumor. The other patient. whose operation occurred early in the series, had a recurrent left atrial myxoma and required a 2nd operation. 37 months after the 1st. This patient was 1 of the 2 whose myxoma had originated from the left atrial appendage. At 1st operation, only the left atrial myxoma (without a cuff of atrial wall) had been excised; at 2nd operation, a cuff was removed, and the surgically created septal defect was repaired by direct suture. Also, the mitral valve was replaced during this 2nd procedure. The patient's postopera- tive course was uneventful.
Three patients were lost to follow-up.
Discussion
Prevalence Primary cardiac tumors are intracavitary, and 80% of them are benign. They account for 5% to 10% of all cardiac neoplasms, the balance of which are secon- dary tumors (therefore metastatic and malignant). Myxomas account for approximately 50% of all primary cardiac neoplasms, and have been reported in all cardiac chambers. Although about 75% occur in the left atrium and 25% in the right,8 multiple myxomas have been reported in 5% of patients with left atrial or left ventricular myxomas, and have on occasion been found in all 4 cardiac cavities.' Myxomas occur predominantly in women in the 3rd to 6th decades of life, and familial tendency has been reported.9 '0
Pathogenesis and Histology That myxomas are true neoplasms is generally agreed.'0 Myxomas are globular or polypoid masses that usually arise from the region of the fossa ovalis and are attached to the underlying endocardium by a pedicle. Myxomas are thought to develop from primitive endothelial or subendocardial cells, or from multipotential mesenchymal cells. To date, there is no general agreement on the cell type observed."
Surgical Treatment of Atrial Myxomas 83Te-xas Heart Institutejournal
Clinical Manifestations Although small tumors may be asymptomatic, the clinical manifestations of atrial myxomas, when they occur, are well recognized. The most common find- ings are symptoms of valvular obstruction and signs of peripheral embolization.i We encountered 3 cases of atrial myxoma with systemic embolization. Sys- temic symptoms such as fever, weight loss, arthralgia, and anemia are among the protean manifestations of myxoma.'2 An early diastolic "tumor plop" and a changing cardiac murmur are rather common physi- cal findings arising from valvular obstruction.10
Classically, myxomas on the left side of the heart, whether atrial or ventricular, can simulate the clinical features of mitral stenosis with regurgitation, since a mobile intra-atrial tumor can obstruct the valve and render it insufficient.10 Enlargement of the left atrium, abnormalities of nonspecific T waves and ST seg- ments, and hypertrophy ofthe right and left ventricles have all been reported.12
Diagnosis Historically, cardiac tumors have been diagnosed by angiocardiography and M-mode echocardiography. (Electrocardiographic findings are usually nonspe- cific.) Transseptal angiocardiography has been used in numerous medical centers, but tumor embolism has been reported with use of this method.13 Pulmo- nary levophase angiocardiography has proved a reasonably accurate method of visualizing a left atrial mass. Yet, in our series, angiocardiography success- fully documented a myxoma in only 1 of the 4 cases in which it was the sole radiologic technique used for diagnosis.
In recent years, closer attention to differential aspects of presenting clinical features-aided by expanded use of phonocardiography, echocardi- ography, and angiocardiography-has increased thfe accuracy of preoperative diagnosis. In 16 of our patients, an atrial mass was documented preopera- tively by M-mode echocardiography.
Now, however, 2-dimensional echocardiography is a safer and probably more accurate method of diagnosing cardiac tumors.1'15 In our last 10 patients, 2-dimensional echocardiography was particularly useful in diagnosis: because of its accuracy, we were able to proceed to surgical repair without angiocar- diography. Two-dimensional echocardiography has also become our 1st choice for detection of late recurrence.
Recommendations for Therapy When a diagnosis of left atrial myxoma has been made, surgery should be performed without delay. 16 Current surgical techniques for treating atrial myxoma include median sternotomy with total cardiopulmo- nary bypass, using moderate hypothermia with cold
potassium cardioplegia. Cardioplegia provides a quiet operative field for meticulous resection of myxoma and for inspection of all 4 chambers.
Tumor fragmentation, followed by embolization of myxomatous debris, can be a serious intraopera- tive complication of this procedure. The risk of this can be greatly reduced, though, by manipulating the heart and the tumor as little as possible during cannulation and tumor excision. Another measure to decrease risk of intraoperative emboli is the inter- position of filters in the cardiotomy suction and arterial lines. Disesa16 has recently described in detail a surgical approach to left atrial myxomas that might serve as a paradigm.
Recurrence Late recurrence of myxoma after surgical excision is a well known complication. The true incidence of such recurrence is difficult to document, but probably ranges from 3% to 6%.1116(-18 The cause of recurrence is not clear, but likely factors include inadequate resection and multicentric growth. In a 1973 report, Kabbani and Cooley'8 reported 1 recurrence among 16 patients (6%) who were evaluated in the late post- operative period. Richardson19 noted 1 recurrence in 27 patients (4%). St. John Sutton12 reported follow-up of 37 patients for a mean period of more than 8 years, during which 2 recurrences (5.4%) were seen. In a series of 33 patients at the Armed Forces Institute of Pathology,20 32 had no recurrence upon long-term follow-up, and the remaining patient died without autopsy 2 years after myxoma resection, for an unknown (but at most 3%) recurrence rate.
In our series, there was 1 recurrence in 17 patients C6%), and this was in a patient seen early in the series, whose original myxoma-attached to the left atrial appendage-had been excised without a cuff of normal tissue. That patient's 2nd myxoma occurred at approximately the same site, and likely arose as a consequence of inadequate resection of the atrial wall where the original tumor had been attached. This emphasized the importance of complete exci- sion of the myxoma, its pedicle, and a cuff of normal tissue, a procedure that we followed thereafter.
Conclusion
Certainly our recent experience, as this series has evolved, indicates an excellent prognosis, following complete excision of benign myxomas. The risks of intraoperative embolization and late recurrence are minimal. Two-dimensional echocardiography has proved an extremely accurate tool in the early diagnosis of intracardiac myxomas, and one that obviates the need for angiocardiography. It also affords excellent visualization of intracardiac masses, as an aid to late follow-up.
84 Surgical Treatment of Atrial Myxomas V'oliime 16, Number 2, 1989
References 1. McAllister HA Jr. Volume 2: tumors of the heart and peri-
cardium. In: Silver MD, ed. Cardiovascular pathology. New York: Churchill Livingstone, 1983:900-43.
2. GoodwinJD, Axel L? AdamsJR, et al. Computed tomography: a new method for diagnosing tumor of the heart. Circulation 1981;63:448-51.
3. Ramsey KJ, Detrano R, Simpfendorfer CC, et al. Evaluation of cardiac tumors with digital subtraction angiography. Cleve Clin Q 1985;52:573-7.
4. Charuzi Y, Bolger A, Beeder C, Lew AS. A new echocardio- graphic classification of left atrial myxoma. Am J Cardiol 1985;55:614-5.
5. Pechacek LW, Gonzalez-Camid F, Hall RJ, et al. The echocar- diographic spectrum of atrial myxoma: a 10-year experience. Tex Heart Inst J 1986;13:179-95.
6. Bateman TM, Sethna DH, Whiting JS, et al. Comprehensive noninvasive evaluation of left atrial myxomas using cardiac cine-computed tomography. J Am Coll Cardiol 1987;9: 1180-3.
7. Crafoord C. Panel discussion on late results of mitral commis- surotomy. In: Lam CR, ed. International symposium on
cardiovascular surgery: studies in physiology, diagnosis and techniques. (Henry Ford Hospital, Detroit, MI) Philadelphia: WB Saunders, 1955:202-3.
8. Silverman NA. Primary cardiac tumors. Ann Surg 1980:191: 127-38.
9. Powers JC, Falkoff M, Heinle RA, et al. Familial cardiac myxoma: emphasis on unusual clinical manifestations. J Thorac Cardiovasc Surg 1979;77:782-9.
Editorial Comment
During the past several years, considerable clinical and research experience with magnetic resonance imaging (MRI) has shown the extraordinary capabili- ties of this new technique, as an aid in cardiac diagnosis. 15 MRI now provides the most precise images of cardiac anatomy currently available and, in addition, may furnish valuable information regarding heart function and metabolism. In MRI, the inherent contrast between the blood pool and the heart struc- tures permits a clearly defined image that makes MRI highly useful in clinical diagnosis.
Considerable information in the medical literature demonstrates the usefulness of MRI in the further evaluation of patients with suspected cardiac masses first indicated by 2-dimensional echocardiography.63 Magnetic resonance imaging can confirm the pres- ence of a mass; show no mass, but delineate an anatomic variant or other abnormality that mimics a mass; or show no mass or other abnormality. There are no reported instances of false negative MRI results.
In depicting a cardiac mass, MRI shows in precise detail the extent and location of the mass within the heart, and its relationships with intracardiac struc-
10. Chitwood WR. Cardiac neoplasms: current diagnosis. pa- thology and therapy: a collective review. J Cardiac Surg 1988;3:119-54.
11. Feldman PS, Horvath E, Kovacs K. An ultrastructural study of seven cardiac myxomas. Cancer 1977;40:2216-32.
12. St. John Sutton MG, Mercier LA, Giuliani ER, Lie JT. Atrial myxomas: a review of clinical experience in 40 patients. Mayo Clin Proc 1980;55:371-6.
13. Pindyck F, Peirce EC III, Baron MG. et al. Embolization of left atrial myxoma after trans-septal cardiac catheterization. Am J Cardiol 1972;30:569-71.
14. Donahoo JS, Weiss JL, Gardner TJ, et al. Current manage- ment of atrial myxoma with emphasis on a new diagnostic technique. Ann Surg 1979;189:763-8.
15. Marvasti MA, Obeid Al, Potts JL. Parker FB. Approach in the management of atrial myxoma with long-term follow-up. Ann Thorac Surg 1984;38:53-8.
16. Disesa VJ, Collins JJ, Cohn LH. Considerations in the surgical management of left atrial myxoma. J Cardiac Surg 1988:3: 15-22.
17. Gerbode F, Kerth WJ, Hill JD. Surgical management of tumors of the heart. Surgery 1967;61:94-101.
18. Kabbani SS, Cooley DA. Atrial myxoma: surgical considera- tions. J Thorac Cardiovasc Surg 1973;65:731-7.
19. Richardson JV, Brandt B, Doty DB. Ehrenhaft JL. Surgical treatment of atrial myxoma: early and late result of 11 operations and review of the literature. Ann Thorac Surg 1979;28:354-8.
20. McAllister HA Jr. Fenoglio jJ. Fascicle 15. 2nd Series: tumors of the cardiovascular system. In: Atlas of tumor pathology. Washington: Armed Forces Institute of Pathology: 1978.
tures, the myocardium, pericardium, and contiguous organs. This is done noninvasively, without contrast material or ionizing radiation, in multiple tomo- graphic planes, and in a wide angle of view. These features should make…
Bum Koo Cho, MD Doo Yun Lee, MD A. Thomas Pezzella, MD Sung Nok Hong, MD Pill Whoon Hong, MD
Key words: Myxoma; heart, neoplasms; heart, atrium; aortocoronary bypass; echocardiography
From: The Department of Thoracic and Cardiovascular Surgery, College of Medi- cine, Yonsei University, Seoul, Korea
Dr. Pezzella was a Visiting Professor in the Division of Cardiothoracic Surgery at Yonsei University during April of 1988, on leave from the Department of Surgery at the University of Massachusetts Medical Center, Worcester, Massachusetts.
Address for reprints: A. Thomas Pezzella, MD, Department of Surgery, University of Massachusetts Medical Center, Worcester, MA 01655
Twenty atrial myxomas were resected in 20 patients with the use of cardiopulmonary bypass, from the beginning of July 1966 through the end of June 1985, at Severance Hospital, Seoul, Korea. Nineteen patients had left atrial myxomas; 1 had a right atrial myxoma. Left atrial myxomas arose from the intra-atrial septum in 17 patients and from the leftatrialappendage in 2patients. The rightatrialmyxoma arose from the fossa ovalis. The 13 female and 7 male patients ranged in age from 14 to 63 years. Symptoms most often reported on presentation were those associated with mitral valve obstruction; other symptoms were associated with systemic embolization.
The 1st 4 patients were tested with angiocardiography alone, and 3 of these were misdiagnosed. The last 16 were testedbyangiocardiography, M-mode echocardiography, and2-dimensional echocardiography, alone or in various combinations, and there were no further misdiagnoses. In our experience, 2-dimensional echocardiography was the most accurate method of diagnosing cardiac tumors.
In 19patients, surgicalapproach was through a median sternotomy; in the 20th patient, approach was through a left thoracotomy, due to a preoperative misdiagnosis of mitral stenosis. No intraoperative embolizations ordeaths occurred. On follow-up of 17patients duringperiods ranging from 6months to 6 years, we hadno late deaths, andonly2patients suffered late complications: 1 had sudden right hemiparesis caused by an embolus 4 months aftersurgery (this improved upon conservative treatment); and 1 hada recurrence of tumor 3 years after surgery (the new myxoma was successfully resected). We conclude thatpatients who have undergone complete excision ofbenign myxomas
nowhave an excellentprognosis, with minimal risk ofintraoperative embolization and late recurrence. We conclude also that 2-dimensional echocardiography is an extremely accurate tool both in early diagnosis of intracardiac myxomas and in late follow-up after resection. (Texas Heart Institute Journal 1989;16:81-6)
B efore 1960, cardiac myxomas were commonly diagnosed as chronic rheumatic heart disease, because of their ability to mimic mitral stenosis.1 Not only have we seen dramatic improvements in diagnostic methods26
since that time, but for more than 30 years7 surgery has offered a cure. Now, diagnosis and treatment have minimized the risks of potentially catastrophic complication so long associated with intracardiac myxoma-most specifically, those of preoperative atrioventricular dysfunction and intraoperative embolization.
Diagnosis must be rapid and correct, however, and resection must be careful and complete, accompanied by thorough removal of all tumor fragments. This report examines 20 patients in retrospection, with emphasis on the evolution at our institution of surgical-but more especially of diagnostic-techniques for the recognition and treatment of atrial myxomas.
Patients and Methods
From the beginning of July 1966 through the end of June 1985, 20 patients underwent surgical resection of an atrial myxoma in Severance Hospital, Seoul, Korea. The 13 female patients (age range, 20 to 63 years) and 7 male patients (age range, 14 to 49 years) had 19 left atrial myxomas and 1 right atrial myxoma. Distribution by age and sex is shown in Table I, while chief complaints upon presentation are listed in Table II.
Surgical Treatment of Atrial Myxomas 81Texas Heart Instituteioumal
Diagnostic Techniques Cardiac catheterization and angiocardiography, M- mode echocardiography, and 2-dimensional echocar- cliography wvere used separately or in combination for diagnosis (Fig. 1). Of the 20 patients, 8 had angio- carcliographic catheterization and 16 had M-mode echlocardiography. Four of these patients underwent both catheterization and M-mode echocardiography, and the last 10 underwent 2-dimensional echocardi- ography in addition to M-mode echocardiography.
Angiocardiography (8)
2-dimensional Echocardiography
M-mode Echocardiography
Fig. 1 Distribution of diagnostic procedures used in 20 cases
of atrial myxoma, from the beginning of July 1966 through the end of June 1985.
In the 4 patients who had both diagnostic catheteri- zation and M-mode echocardiography, the echocar- diographic results were considered diagnostic. The 2 patients who received only M-mode echocardiogra- phy (see Fig. 1) were diagnosed without supplemen- tal radiography; and the 10 patients who received both M-mode and 2-dimensional echocardiography were diagnosed after evaluation of both results, with the 2-dimensional echocardiograms accepted as definitive.
Diagnostic Findings Of the 4 patients who had catheterization alone, 3 were misdiagnosed preoperatively as having mitral regurgitation secondary to mitral stenosis, while 1 was diagnosed correctly as having mitral regurgita- tion secondary to an intra-atrial mass. All other diagnoses, made with the assistance of echocardi- ography, proved accurate. Nineteen ofthe 20 patients proved to have left atrial myxoma, correctly diag- nosed preoperatively, except for the 3 misdiagnoses of mitral stenosis. One patient had right atrial myxoma, and this was diagnosed correctly by echocardiogra- phy. Other findings were made only upon operation.
Surgical Findings The sites to which the stalks of the atrial myxomas were attached are summarized in Table III: most commonly, attachment was to the fossa ovalis, and with 2 exceptions (attachments to the atrial append- age) the other neoplasms also involved the interatrial septum. Diameters of the atrial myxomas, measured
TABLE 1. Age and Sex Distribution of 20 Patients with Atrial Myxoma
Age Male Female Total
50-59 - 2 2 60-69 - 2 2
7 13 20
TABLE II. Chief Complaints upon Presentation, in 20 Patients with Atrial Myxoma
No. of Chief Complaint Occurrences
Dyspnea on exertion 14
Syncope 2 Weakness of right arm 1
Cough 1 Anorexia 1
Site No. of Cases
Left atrial septum (through to the fossa ovalis) 1 2 Left atrial septum (not fossa ovalis) 5 Left atrial appendage* 2
Fossa ovalis in right atrium 1
20
* The recurrent myxoma (arising from 1 patient's left atrial appendage) is not included in this summary.
TABLE IV. Surgical Findings
Left atrial myxoma 16 Left atrial myxoma and mitral regurgitation 2
Left atrial myxoma and atrial septal defect 1
Right atrial myxoma and patent foramen ovale 1
82 Surgical Treatment of Atrial Myxomas V'olume 16, N'timber 2, 1989
laterally and discounting pedicles, ranged from 4 cm to 10 cm. Associated surgical findings (Table IV) in the left atrial myxoma group included mitral regurgi- tation (2 cases) and atrial septal defect (1 case). The patient with a right atrial myxoma was found also to have a patent foramen ovale. In our series, there were no instances of myxomas in 2 or more cardiac cavities.
Surgical Technique In 19 patients, the atrial myxomas were excised through a median sternotomy, under cardiopulmo- nary bypass. In the remaining patient-whose pre- operative diagnosis had been severe mitral stenosis with mild mitral regurgitation, and forwhom a closed mitral commissurotomy had been planned-approach was through a left thoracotomy; subsequently, a left atrial mass was discovered by index-finger palpation, and excised under cardiopulmonary bypass.
In all cases, cardiac arrest was achieved with topical hypothermia, and-from 1978 on-with the adjunct of cold potassium cardioplegia. Typically, a left atrial incision was made posterior to the interatrial groove. The attachment point of the tumor was then revealed through gentle manual exposure of the atrium, with care taken to avoid touching the pedicle or its attachment point. Before resection, the other 4 cardiac chambers were explored for the occasional multicentric tumor. The pedicle was then excised completely, along with a cuff of the tissue to which it was attached (usually the interatrial septum). To minimize the risk of embolization, great care was taken to handle the pedicle gently, and to remove any residual tumor debris from the surgical field.
The surgically created septal defect was closed by the following methods: in 10 instances, by direct suture alone, with running monofilament; in 8 in- stances, by prosthetic patch; and in 2 instances, by both direct suture and patch placement. Two patients required mitral valve replacement in addition to myxoma resection. In 1 of them, the mitral valve was not replaced until the day following initial surgery, when it became evident that severe preoperative mitral regurgitation had not abated. In the 1 instance of patent foramen ovale, the shunt was closed with direct suture.
The 2 patients whose myxomas arose from the atrial appendage did not require septostomy.
Gross and Microscopic Laboratory Findings The myxomas in our series consisted, upon gross observation, of a soft gelatinous tissue covered by a thin, glistening endothelial layer. On histologic ex- amination, the tumors were found to be benign and to comprise myxoma cells, endothelial cells, macro- phages, and a variety of intermediate forms, all within
a polysaccharide-rich ground substance. Numerous small blood vessels coursed through these tumors. and many ofthe macrophages were laden with hemo- siderin.
Results
Postoperative follow-up from 6 months to 6 years in duration was achieved in the cases of 17 patients. 15 of whom recovered with no postoperative complica- tions and remained in excellent condition.
Of the remaining 2 patients, 1 experienced sudden right hemiparesis 4 months after surgery, possibly caused by embolization of tumor debris; but the patient improved steadily with conservative treat- ment. A 2-dimensional echocardiogram was negative for residual or recurrent tumor. The other patient. whose operation occurred early in the series, had a recurrent left atrial myxoma and required a 2nd operation. 37 months after the 1st. This patient was 1 of the 2 whose myxoma had originated from the left atrial appendage. At 1st operation, only the left atrial myxoma (without a cuff of atrial wall) had been excised; at 2nd operation, a cuff was removed, and the surgically created septal defect was repaired by direct suture. Also, the mitral valve was replaced during this 2nd procedure. The patient's postopera- tive course was uneventful.
Three patients were lost to follow-up.
Discussion
Prevalence Primary cardiac tumors are intracavitary, and 80% of them are benign. They account for 5% to 10% of all cardiac neoplasms, the balance of which are secon- dary tumors (therefore metastatic and malignant). Myxomas account for approximately 50% of all primary cardiac neoplasms, and have been reported in all cardiac chambers. Although about 75% occur in the left atrium and 25% in the right,8 multiple myxomas have been reported in 5% of patients with left atrial or left ventricular myxomas, and have on occasion been found in all 4 cardiac cavities.' Myxomas occur predominantly in women in the 3rd to 6th decades of life, and familial tendency has been reported.9 '0
Pathogenesis and Histology That myxomas are true neoplasms is generally agreed.'0 Myxomas are globular or polypoid masses that usually arise from the region of the fossa ovalis and are attached to the underlying endocardium by a pedicle. Myxomas are thought to develop from primitive endothelial or subendocardial cells, or from multipotential mesenchymal cells. To date, there is no general agreement on the cell type observed."
Surgical Treatment of Atrial Myxomas 83Te-xas Heart Institutejournal
Clinical Manifestations Although small tumors may be asymptomatic, the clinical manifestations of atrial myxomas, when they occur, are well recognized. The most common find- ings are symptoms of valvular obstruction and signs of peripheral embolization.i We encountered 3 cases of atrial myxoma with systemic embolization. Sys- temic symptoms such as fever, weight loss, arthralgia, and anemia are among the protean manifestations of myxoma.'2 An early diastolic "tumor plop" and a changing cardiac murmur are rather common physi- cal findings arising from valvular obstruction.10
Classically, myxomas on the left side of the heart, whether atrial or ventricular, can simulate the clinical features of mitral stenosis with regurgitation, since a mobile intra-atrial tumor can obstruct the valve and render it insufficient.10 Enlargement of the left atrium, abnormalities of nonspecific T waves and ST seg- ments, and hypertrophy ofthe right and left ventricles have all been reported.12
Diagnosis Historically, cardiac tumors have been diagnosed by angiocardiography and M-mode echocardiography. (Electrocardiographic findings are usually nonspe- cific.) Transseptal angiocardiography has been used in numerous medical centers, but tumor embolism has been reported with use of this method.13 Pulmo- nary levophase angiocardiography has proved a reasonably accurate method of visualizing a left atrial mass. Yet, in our series, angiocardiography success- fully documented a myxoma in only 1 of the 4 cases in which it was the sole radiologic technique used for diagnosis.
In recent years, closer attention to differential aspects of presenting clinical features-aided by expanded use of phonocardiography, echocardi- ography, and angiocardiography-has increased thfe accuracy of preoperative diagnosis. In 16 of our patients, an atrial mass was documented preopera- tively by M-mode echocardiography.
Now, however, 2-dimensional echocardiography is a safer and probably more accurate method of diagnosing cardiac tumors.1'15 In our last 10 patients, 2-dimensional echocardiography was particularly useful in diagnosis: because of its accuracy, we were able to proceed to surgical repair without angiocar- diography. Two-dimensional echocardiography has also become our 1st choice for detection of late recurrence.
Recommendations for Therapy When a diagnosis of left atrial myxoma has been made, surgery should be performed without delay. 16 Current surgical techniques for treating atrial myxoma include median sternotomy with total cardiopulmo- nary bypass, using moderate hypothermia with cold
potassium cardioplegia. Cardioplegia provides a quiet operative field for meticulous resection of myxoma and for inspection of all 4 chambers.
Tumor fragmentation, followed by embolization of myxomatous debris, can be a serious intraopera- tive complication of this procedure. The risk of this can be greatly reduced, though, by manipulating the heart and the tumor as little as possible during cannulation and tumor excision. Another measure to decrease risk of intraoperative emboli is the inter- position of filters in the cardiotomy suction and arterial lines. Disesa16 has recently described in detail a surgical approach to left atrial myxomas that might serve as a paradigm.
Recurrence Late recurrence of myxoma after surgical excision is a well known complication. The true incidence of such recurrence is difficult to document, but probably ranges from 3% to 6%.1116(-18 The cause of recurrence is not clear, but likely factors include inadequate resection and multicentric growth. In a 1973 report, Kabbani and Cooley'8 reported 1 recurrence among 16 patients (6%) who were evaluated in the late post- operative period. Richardson19 noted 1 recurrence in 27 patients (4%). St. John Sutton12 reported follow-up of 37 patients for a mean period of more than 8 years, during which 2 recurrences (5.4%) were seen. In a series of 33 patients at the Armed Forces Institute of Pathology,20 32 had no recurrence upon long-term follow-up, and the remaining patient died without autopsy 2 years after myxoma resection, for an unknown (but at most 3%) recurrence rate.
In our series, there was 1 recurrence in 17 patients C6%), and this was in a patient seen early in the series, whose original myxoma-attached to the left atrial appendage-had been excised without a cuff of normal tissue. That patient's 2nd myxoma occurred at approximately the same site, and likely arose as a consequence of inadequate resection of the atrial wall where the original tumor had been attached. This emphasized the importance of complete exci- sion of the myxoma, its pedicle, and a cuff of normal tissue, a procedure that we followed thereafter.
Conclusion
Certainly our recent experience, as this series has evolved, indicates an excellent prognosis, following complete excision of benign myxomas. The risks of intraoperative embolization and late recurrence are minimal. Two-dimensional echocardiography has proved an extremely accurate tool in the early diagnosis of intracardiac myxomas, and one that obviates the need for angiocardiography. It also affords excellent visualization of intracardiac masses, as an aid to late follow-up.
84 Surgical Treatment of Atrial Myxomas V'oliime 16, Number 2, 1989
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Editorial Comment
During the past several years, considerable clinical and research experience with magnetic resonance imaging (MRI) has shown the extraordinary capabili- ties of this new technique, as an aid in cardiac diagnosis. 15 MRI now provides the most precise images of cardiac anatomy currently available and, in addition, may furnish valuable information regarding heart function and metabolism. In MRI, the inherent contrast between the blood pool and the heart struc- tures permits a clearly defined image that makes MRI highly useful in clinical diagnosis.
Considerable information in the medical literature demonstrates the usefulness of MRI in the further evaluation of patients with suspected cardiac masses first indicated by 2-dimensional echocardiography.63 Magnetic resonance imaging can confirm the pres- ence of a mass; show no mass, but delineate an anatomic variant or other abnormality that mimics a mass; or show no mass or other abnormality. There are no reported instances of false negative MRI results.
In depicting a cardiac mass, MRI shows in precise detail the extent and location of the mass within the heart, and its relationships with intracardiac struc-
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16. Disesa VJ, Collins JJ, Cohn LH. Considerations in the surgical management of left atrial myxoma. J Cardiac Surg 1988:3: 15-22.
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19. Richardson JV, Brandt B, Doty DB. Ehrenhaft JL. Surgical treatment of atrial myxoma: early and late result of 11 operations and review of the literature. Ann Thorac Surg 1979;28:354-8.
20. McAllister HA Jr. Fenoglio jJ. Fascicle 15. 2nd Series: tumors of the cardiovascular system. In: Atlas of tumor pathology. Washington: Armed Forces Institute of Pathology: 1978.
tures, the myocardium, pericardium, and contiguous organs. This is done noninvasively, without contrast material or ionizing radiation, in multiple tomo- graphic planes, and in a wide angle of view. These features should make…
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