A previously healthy 36-year-old male presented with a one-month history of shortness of breath and fatigue. Cardiovascular examination revealed jugular venous distension (JVD) and grade II/IV mid diastolic murmur at the right lower sternal border. Routine laboratory studies, electrocardiogram, and chest X-ray were all normal. A transthoracic echocardiogram (TTE) showed a large mass, measuring 5.5x5 cm occupying the right atrium (Figure 1). A computed tomography (CT) scan of the chest and abdomen revealed a heterogeneous mass in the right atrium invading the inferior vena cava (IVC) (Figure 2). Two days later, he underwent surgical removal of the mass (Figure 3).
| Figure 1 |
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(A-B) Apical four-chamber two-dimensional (2-D) and three-dimensional (3-D) view of the mass occupying the right atrium. (C) Short axis of the aortic valve showing the right atrial mass protruding into the right ventricle. (D) Subcostal view of the right atrial mass pushing the interatrial septum toward the left atrium.
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| Figure 2 |
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(A) Coronal and (B) sagittal sections of CT of the chest showing a huge heterogeneous mass in the right atrium invading the inferior vena cava.
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| Figure 3 |
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Surgical specimen of right atrium mass measuring 5x5 cm.
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The correct answer is: C. Angiosarcoma.
The large size of the mass and its extension into the IVC indicate an invasive process.1 Moreover, the CT scan images shows heterogeneous contrast enhancement of the mass. All of these features are characteristic of primary malignant cardiac tumors (typically sarcoma). Angiosarcoma is the most common type of cardiac sarcoma.2 They appear more commonly in the right atrium and typically occur in males between the third and fifth decades of life. The clinical presentation is variable, ranging from an incidental finding on imaging study to cardiogenic shock due to cardiac tamponade. The highly aggressive behavior of the tumor results in dismal prognosis. The mean survival after diagnosis is less than a year.3 If complete surgical resection is possible, surgery followed by adjuvant chemotherapy provides better outcome. However, complete resection remains a difficult goal to achieve due to the high incidence of metastasis at the time of diagnosis (up to 80%).4 In a recent large case series of cardiac angiosarcoma, complete resection with negative margins (R0) was achieved in only 10 of 75 (13.3%) patients.5 Nevertheless, palliative debulking surgery may provide substantial symptoms relief. Ex vivo removal of the tumor and autologous transplantation of the heart have been described in left sided angiosarcoma with no significant effect on survival.6
Surgical Approach
Resection and Reconstruction Technique
Atrial tumors are usually excised with a full thickness section of the atrial wall around the tumor attachment site. Such techniques are optimal for localized disease and requires pericardial or Dacron patch to reconstruct the atrium.7 This can be challenging when the tumors involve the atrioventricular valves or coronary sinus.
Typically, a median sternotomy is performed to access the tumor site. However, in cases of tumors extending into the IVC, the incision may be extended into the abdomen as midline incision for optimal exposure. Abdominal tumors extending into the IVC to the right atrium are best approached as a combined procedure, with simultaneous removal of the infradiaphragmatic tumor and its extension up the IVC into the right atrium.
After preparation for cardiopulmonary bypass (CPB), the superior vena cava (SVC) is directly cannulated, CBP is established and the patient cooled to 22 degrees centigrade. The aorta is clamped, cardioplegic solution infused, SVC tape snugged, and right atrium opened. Blood returning into the right atrium is aspirated with a high vacuum suction and discarded to avoid tumor embolization. This tumor had already metastasized to the liver as shown in the CT scan images. Therefore, a curative resection was not feasible. The patient underwent palliative surgery with the tumor resected en bloc from the atrial wall and with blunt dissection of the tumor from the IVC. Following surgery, the patient received chemotherapy with adriamycin based regimen. Histopathology was confirmatory of cardiac angiosarcoma. At his one-year follow-up visit, the patient had local recurrence in the right atrium with new liver and lung metastatic disease. He died shortly thereafter.
Liver Exclusion Technique
Vascular exclusion of the liver with extracorporeal circulation technique can be considered when curative resection is planned for tumors with IVC extension. Interruption of hepatic inflow to the liver is safe for up to one hour.8 Coordination between the hepatobilary and cardiothoracic surgery teams is indispensable. For optimal exposure, a thoracoabdominal approach is recommended. Dual cannulation of the SVC and infrahepatic IVC is performed for CBP. Triple vascular clamping of the hepatic pedicle via a Pringle maneuver, then the infrahepatic IVC and SVC are then performed.9 As described earlier, an extensive resection of the tumor from the right atrium and IVC is then performed.
Ex Situ Resection Technique
Ex situ resection, also known as autotransplantation, was first described in 1985 by Cooley et al.10 CPB is established using bicaval venous cannulation. However, different cannulation sites such as the femoral vein maybe needed depending on the tumor site. Cardiac explantation is performed by transecting the SVC, IVC, great vessels, and atrial wall. Followed by complete tumor resection ex vivo.11,12 The goal is to achieve complete tumor resection with free margins. Reimplantation with cardiac reconstruction and weaning from CBP is performed next. Deep hypothermia and circulatory arrest at 16-18 degrees centigrade may be a valuable adjunct in combination with any or all of the above techniques when a curative resection is contemplated.
More Information on Answer Option A: Cardiac myxomas typically originate from the fossa ovalis region with a striking predilection for the left atrium. In contrast, right atrial myxoma occurs only in 20% of cases.
More Information on Answer Option B: In the absence of underlying cardiac pathology or hypercoagulable states, formation of intracardiac thrombi are distinctly rare. If found, right sided thrombus almost always related to foreign body such as mechanical prosthesis, indwelling catheters and/or pacemaker/implantable cardioverter-defibrillator (ICD) leads.
More Information on Answer Option D: Although carcinoid tumors affect the right heart chambers, they mainly affect the valves anatomy via deposition of fibrous plaques, leading to the characteristics triad of thickened, shorten, and fixed tricuspid and/or pulmonic valve with subsequent regurgitation or stenosis. Nonetheless, cardiac mass is not typical feature of carcinoid tumor.
More Information on Answer Option E: Renal cell carcinoma (hypernephroma) may extend to the heart through the IVC. A fingerlike projection, rather than a large mass, may protrude into the right atrium from the IVC. The tumor can be followed retrograde back to the kidneys. Uterine tumors and thymoma may present in this fashion as well. Nonetheless, this patient's CT scan images show no evidence of renal mass.
References
- Araoz PA, Eklund HE, Welch TJ, Breen JF. CT and MR imaging of primary cardiac malignancies. Radiographics 1999;19:1421-34.
- Meng Q, Lai H, Lima J, Tong W, Qian Y, Lai S. Echocardiographic and pathologic characteristics of primary cardiac tumors: A study of 149 cases. Int J Cardiol 2002;84:69-75.
- Butany J, Nair V, Naseemuddin A, Nair GM, Catton C, Yau T. Cardiac tumours: Diagnosis and management. Lancet Oncol 2005;6:219-28.
- Kim CH, Dancer JY, Coffey D, et al. Clinicopathologic study of 24 patients with primary cardiac sarcomas: A 10-year single institution experience. Hum Pathol 2008;39:933-8.
- Isambert N, Ray-Coquard I, Italiano A, et al. Primary cardiac sarcomas: A retrospective study of the french sarcoma group. Eur J Cancer 2014;50:128-36.
- Blackmon SH, Patel AR, Bruckner BA, et al. Cardiac autotransplantation for malignant or complex primary left-heart tumors. Tex Heart Inst J 2008;35:296-300.
- Benassi F, Maiorana A, Melandri F, Stefanelli G. A case of primary cardiac angiosarcoma: extensive right atrial wall reconstruction with autologous pericardium. J Card Surg 2010;25:282-4.
- Huguet C, Gavelli A, Bona S. Hepatic resection with ischemia of the liver exceeding one hour. J Am Coll Surg 1994;178:454-8.
- Savier E, Siksik JM, Hannoun L. Vascular exclusion of the liver. J Visc Surg 2011;148:31-8.
- Cooley DA, Reardon MJ, Frazier OH, Angelini P. Human cardiac explantation and autotransplantation: Application in a patient with a large cardiac pheochromocytoma. Tex Heart Inst J 1985;12:171-6.
- Hoffmeier A, Scheld HH, Tjan TD, et al.. 2003. Ex situ resection of primary cardiac tumors." Thorac Cardiovasc Surg 2013;51:99-101.
- Reardon MJ, Malaisrie SC, Walkes JC, et al. Cardiac autotransplantation for primary cardiac tumors. Ann Thorac Surg 2006;82:645-50.
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