Cardiac herniation after resection of pericardial thymic cyst
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《血管的通路杂志》
Department of Cardiac, Thoracic and Vascular Surgery, National University Hospital Singapore, 5 Lower Kentridge Road, 119074 Singapore
Abstract
Cardiac herniation following pericardial resection is a rare and potentially fatal complication. We present a case of a cardiac herniation after excision of pericardial thymic cyst. The patient had cardiac arrest one hour after surgery. Re-thoracotomy in the high dependency care unit, and reduction of cardiac herniation were done. There was no case report in the literature of cardiac herniation after excision of pericardial tumor.
Key Words: Thymic cyst; Cardiac herniation; Pericardial tumor
1. Case history
The patient was a 21-year-old Chinese man. Chest X-ray during a routine medical check revealed a large cardiac shadow. Computed tomography showed a large (7.2x7.5x8.4 cm) semi-solid mass arising from the left side of the pericardium. Transthoracic echocardiography showed normal cardiac function. He underwent excision of the mass and attached underlying pericardium through a left lateral thoracotomy. After resecting the tumor, there was a defect of the pericardium about 8 cm in diameter. Patient was extubated and transferred to the high dependency care unit in stable condition. After about one hour, he suddenly developed ventricular tachycardia with no cardiac output. After one minute of cardio-respiratory resuscitation, electrocardiogram reverted to normal sinus rhythm, with widespread ST elevation. Chest roentgenograph showed unusual shift of the cardiac shadow (Fig. 1). Ventricular tachycardia recurred and persisted, requiring closed chest cardiac massage. Emergency reopening of the thoracic incision was performed in the high dependency care unit. One-third of left ventricle was found to have irreducibly herniated out through the area of resected pericardium. The herniated part of left ventricle appeared blue and non-contractile. Internal cardiac massage was performed and pericardial incision was extended superiorly and inferiorly, releasing the constriction. The heart began to be reperfused and had fairly good contractions again. Intraaortic balloon pumping (IABP) was inserted because of concerns about repeated non-sustained ventricular tachycardia. Haemodynamically the patient's condition became stable and the chest was closed. The patient was extubated and IABP was removed two days later. The patient was discharged without any neurological deficit or further complication on 7th post-operative day. When he was reviewed in the follow-up clinic one week and one month later, he was well and had no sequelae.
Microscopic section showed a cyst with fibrous wall lined by columnar epithelium and thymic tissue was seen in the wall. There was no malignancy. Histological diagnosis of this tumor was thymic cyst.
2. Comment
Thymic cyst is a benign tumor and represents 2% of mediastinal tumors. They are usually asymptomatic and discovered incidentally on a chest roentgenograph. Usually the cyst is located at neck or anterior mediastinal compartment. Histologically cysts are composed of a thin capsule lined with cuboidal, squamous, or columnar epithelium. Thymic tissue is present in the wall and the cyst most often contains a clear serous fluid. Radiographically thymic cyst appears as a smooth, circumscribed mass. It may be difficult to distinguish thymic cyst from potentially malignant lesions with cystic changes. Then surgical resection and accurate diagnosis seems to be the best option for treatment of this tumor.
There are a few reports of atypical location of thymic cyst; middle mediastinum [1], pericardium [2,3]. Preoperatively we had diagnosed this tumor as pericardial cyst, based on the findings of computed tomography and chest roentgenograph. Without histological evaluation, it is difficult to diagnose this tumor accurately. As with most pericardial tumors, surgical resection resulted in definitive diagnosis and treatment.
Cardiac herniation is a rare and life-threatening complication. It can occur in association with congenital defects, traumatic injury [4], and post-operative status of pericardial pneumonectomy [5–7]. Signs and symptom of cardiacherniation depends on the side of herniation. On the right side, superior vena cava syndrome caused by torsion may occur, resulting in a hypotension. On the left side, symptom results from strangulation of the ventricle including arrhythmia, myocardiac ischemia, and hypotension. Survival can be achieved by early diagnosis and immediate relocation of the heart and pericardium.
Cardiac herniation after pneumonectomy is well described in the literature. After pneumonectomy the empty space is large. Our patient was a post-operative herniation after pericardial thymic cyst resection. A pericardial defect of about 8 cm was created after excision of attached pericardium. The left ventricular apex herniated through this defect and the clinical situation became very critical. It was fortunate that prompt and appropriate measures were instituted and he had no sequelae from this rare complication.
We conclude that any patients who undergo pericardial resection should have a large area of resection. And if it is possible, we should close all pericardial defects that potentially lead to cardiac herniation. A small pericardial defect of the size of ventricular apex may be a potential source of irreducible cardiac herniation and strangulation.
References
van Klaveren RJ, Festen J, Lacquet LK, Wiersma-Tilburg JM, Cox AL. A symptomatic thymic cyst in the middle mediastinum. J Thorac Cardiovasc Surg 1994;107:1169–1171.
Monnier G, Guerard S, Godon P, Heyraud JD, Brichon PY, Van De Walle JP, Brion R. A new case of pericardial thymic cyst. Arch Mal Coeur Vaiss 2000;93:875–878.
Ceupens H. Thymic cyst in an usual site. Neth J Surg 1984;36:17–19.
Janson JT, Harris DG, Pretorius J, Rossouw GJ. Pericardial rupture and cardiac herniation after blunt chest trauma. Ann Thorac Surg 2003;75:581–582.
Montero CA, Gimferrer JM, Fita G, Serra M, Catalan M, Canalis E. Unexpected postoperative course after right pneumonectomy. Chest 2000;117:1184–1185.
Buniva P, Aluffi A, Rescigno G, Rademacher J, Nazari S. Cardiac herniation and torsion after partial pericardiectomy during right pneumonectomy. Tex Heart Inst J 2001;28:73.
Baisi A, Cioffi V, Nosotti M, De Simone MD, Rosso L, Santambrogio L. Intrapericardial left pneumonectomy after induction chemotherapy: the risk of cardiac herniation. J Thorac Cardiothorac Surg 2002;123:1206–1207.(Satoshi Numata, Winn Maun)
Abstract
Cardiac herniation following pericardial resection is a rare and potentially fatal complication. We present a case of a cardiac herniation after excision of pericardial thymic cyst. The patient had cardiac arrest one hour after surgery. Re-thoracotomy in the high dependency care unit, and reduction of cardiac herniation were done. There was no case report in the literature of cardiac herniation after excision of pericardial tumor.
Key Words: Thymic cyst; Cardiac herniation; Pericardial tumor
1. Case history
The patient was a 21-year-old Chinese man. Chest X-ray during a routine medical check revealed a large cardiac shadow. Computed tomography showed a large (7.2x7.5x8.4 cm) semi-solid mass arising from the left side of the pericardium. Transthoracic echocardiography showed normal cardiac function. He underwent excision of the mass and attached underlying pericardium through a left lateral thoracotomy. After resecting the tumor, there was a defect of the pericardium about 8 cm in diameter. Patient was extubated and transferred to the high dependency care unit in stable condition. After about one hour, he suddenly developed ventricular tachycardia with no cardiac output. After one minute of cardio-respiratory resuscitation, electrocardiogram reverted to normal sinus rhythm, with widespread ST elevation. Chest roentgenograph showed unusual shift of the cardiac shadow (Fig. 1). Ventricular tachycardia recurred and persisted, requiring closed chest cardiac massage. Emergency reopening of the thoracic incision was performed in the high dependency care unit. One-third of left ventricle was found to have irreducibly herniated out through the area of resected pericardium. The herniated part of left ventricle appeared blue and non-contractile. Internal cardiac massage was performed and pericardial incision was extended superiorly and inferiorly, releasing the constriction. The heart began to be reperfused and had fairly good contractions again. Intraaortic balloon pumping (IABP) was inserted because of concerns about repeated non-sustained ventricular tachycardia. Haemodynamically the patient's condition became stable and the chest was closed. The patient was extubated and IABP was removed two days later. The patient was discharged without any neurological deficit or further complication on 7th post-operative day. When he was reviewed in the follow-up clinic one week and one month later, he was well and had no sequelae.
Microscopic section showed a cyst with fibrous wall lined by columnar epithelium and thymic tissue was seen in the wall. There was no malignancy. Histological diagnosis of this tumor was thymic cyst.
2. Comment
Thymic cyst is a benign tumor and represents 2% of mediastinal tumors. They are usually asymptomatic and discovered incidentally on a chest roentgenograph. Usually the cyst is located at neck or anterior mediastinal compartment. Histologically cysts are composed of a thin capsule lined with cuboidal, squamous, or columnar epithelium. Thymic tissue is present in the wall and the cyst most often contains a clear serous fluid. Radiographically thymic cyst appears as a smooth, circumscribed mass. It may be difficult to distinguish thymic cyst from potentially malignant lesions with cystic changes. Then surgical resection and accurate diagnosis seems to be the best option for treatment of this tumor.
There are a few reports of atypical location of thymic cyst; middle mediastinum [1], pericardium [2,3]. Preoperatively we had diagnosed this tumor as pericardial cyst, based on the findings of computed tomography and chest roentgenograph. Without histological evaluation, it is difficult to diagnose this tumor accurately. As with most pericardial tumors, surgical resection resulted in definitive diagnosis and treatment.
Cardiac herniation is a rare and life-threatening complication. It can occur in association with congenital defects, traumatic injury [4], and post-operative status of pericardial pneumonectomy [5–7]. Signs and symptom of cardiacherniation depends on the side of herniation. On the right side, superior vena cava syndrome caused by torsion may occur, resulting in a hypotension. On the left side, symptom results from strangulation of the ventricle including arrhythmia, myocardiac ischemia, and hypotension. Survival can be achieved by early diagnosis and immediate relocation of the heart and pericardium.
Cardiac herniation after pneumonectomy is well described in the literature. After pneumonectomy the empty space is large. Our patient was a post-operative herniation after pericardial thymic cyst resection. A pericardial defect of about 8 cm was created after excision of attached pericardium. The left ventricular apex herniated through this defect and the clinical situation became very critical. It was fortunate that prompt and appropriate measures were instituted and he had no sequelae from this rare complication.
We conclude that any patients who undergo pericardial resection should have a large area of resection. And if it is possible, we should close all pericardial defects that potentially lead to cardiac herniation. A small pericardial defect of the size of ventricular apex may be a potential source of irreducible cardiac herniation and strangulation.
References
van Klaveren RJ, Festen J, Lacquet LK, Wiersma-Tilburg JM, Cox AL. A symptomatic thymic cyst in the middle mediastinum. J Thorac Cardiovasc Surg 1994;107:1169–1171.
Monnier G, Guerard S, Godon P, Heyraud JD, Brichon PY, Van De Walle JP, Brion R. A new case of pericardial thymic cyst. Arch Mal Coeur Vaiss 2000;93:875–878.
Ceupens H. Thymic cyst in an usual site. Neth J Surg 1984;36:17–19.
Janson JT, Harris DG, Pretorius J, Rossouw GJ. Pericardial rupture and cardiac herniation after blunt chest trauma. Ann Thorac Surg 2003;75:581–582.
Montero CA, Gimferrer JM, Fita G, Serra M, Catalan M, Canalis E. Unexpected postoperative course after right pneumonectomy. Chest 2000;117:1184–1185.
Buniva P, Aluffi A, Rescigno G, Rademacher J, Nazari S. Cardiac herniation and torsion after partial pericardiectomy during right pneumonectomy. Tex Heart Inst J 2001;28:73.
Baisi A, Cioffi V, Nosotti M, De Simone MD, Rosso L, Santambrogio L. Intrapericardial left pneumonectomy after induction chemotherapy: the risk of cardiac herniation. J Thorac Cardiothorac Surg 2002;123:1206–1207.(Satoshi Numata, Winn Maun)