- Email: [email protected]
Vagal schwannoma
1370
Ann Thorac Surg 1991:5213&71
CORRESPONDENCE
judge, but I commend it as a possibility to be considered in the various situations that we have described in our report. I agree entirely with Dr Santos about the acute rupture and that our method of internal drainage is unlikely to be rewarded with success. I congratulate him on his technique of pleural irrigation, which should be considered in the presence of gross mediastinal sepsis. Our personal preference is for early ruptures to be repaired directly, but in patients in whom the rupture is more than 24 hours old, as is very often the case, we have opted for cervical esophagostomy, subtotal esophageal resection, and gastrostomy to be followed at a later date by reconstituting swallowing with a gastric pull-up. Clearly there are patients who at the time of presentation are not fit to withstand such a major operation, and Dr Santos’ alternative could be life saving and buy time until definitive treatment is more appropriate.
K . M . Pagliero, FRCS Royal Devon G. Exeter Hospital Barrack Rd Exeter EX2 SDW England
Retrograde Disc Escape in a Harken Mitral Valve Prosthesis 21 Years After Implantation To the Editor: The Harken discoid mitral valve, introduced in 1967 [l]and available in three sizes (small, medium, and large), consisted of a barium-impregnated silicone rubber disc inside a highly polished titanium cage, with two metallic struts crossing each other at 90-degree angles. Scarce data are published on mechanical dysfunctions of this valve or its long-term performance. We have seen a rare type of dysfunction very late (21 years) after implantation. A 54-year-old woman received a Harken medium-size mitral valve in 1969 for severe mitral regurgitation early after attempted redo mitral commissurotomy. In 1981 she had a stroke (left hemiparesis) followed by complete neurological recovery. She remained in New York Heart Association class I or 11 up to May 1990 when sudden respiratory distress was noted. On admission the patient was in pulmonary edema and no prosthetic sounds were heard; she was intubated, and mechanical ventilation and inotropic support were started. Echocardiography suggested mitral valve thrombosis and massive tricuspid regurgitation. Thrombus lysis with anisoylated plasminogen streptokinase activator complex was attempted and followed by some clinical improvement; the physician caring for the patient reported reappearance of prosthetic valve sounds. Later on, the clinical status of the patient worsened and high fever appeared. A new color echocardiogram and Doppler study suggested mild mitral and moderate tricuspid regurgitation. Hours later giant V waves were noted in the capillary wedge pressure and a new echocardiogram showed massive mitral regurgitation. At operation the left atrium was partially covered by mural thrombus with some areas of calcification, and the disc of the prosthesis was found freely floating in the atrium. On closer examination the disc had a nick in one of the borders, but no thrombus or any other macroscopic abnormality was detected. The cage of the prosthesis was well incorporated into the annulus, without any signs of thrombosis, leak, or infection; no wear of the seat was identified. The cage was explanted and a 29-mm St. Jude Medical valve prosthesis was implanted with standard techniques. Continuous hemodialysis for established renal failure was performed during bypass. Respiratory, hepatic, and renal failure requiring hemodialysis, as well as severe neurological dysfunction, complicated the first postoperative days, but the patient subsequently improved and was finally
discharged in good condition. Six months after operation she was leading an active life, again in functional class 11. Discoid valve prostheses, mainly used in the late 1960s and early 1970s, showed vulnerability to catastrophic failure and high rates of thromboembolism as their most important weaknesses. Retrograde disc escape into the left atrium is a rare complication of discoid valves, previously reported [Z] in a patient with a Cross-Jones mitral valve prosthesis. The echocardiographic sequence of events in our patient, suggesting impaction of the disc eventually leading to retrograde disc escape, seems rather unusual. Although valve thrombosis may be more frequent than disc variance in patients with discoid valve prostheses [3], we now believe that urgent operation instead of thrombolysis should be performed in a patient with signs of obstruction of a Harken valve prostheses if the diagnosis of disc variance cannot be ruled out.
Eduardo Otero-Coto, M D , PhD Angel Silla, M D luan A. Casillas, M D , PhD Services of Cardiovascular Surgery and lntensive Medicine Hospital de Alicante CIMaestro Alonso 109 Alicante 03010, Spain
References 1. Harken DE, Matloff JM, Zuckerman W, Chaux A. A new mitral valve. J Thorac Cardiovasc Surg 1968;55:369-78. 2. Lukacs L, Lonyai T. A unique malfunction of Cross-Jones Mitral valve prosthesis. J Cardiovasc Surg 1980;21:954. 3. Hylen JC. Mechanical malfunction and thrombosis of prosthetic heart valves. Am J Cardiol 1972;30:396404.
Vagal Schwannoma To the Editor: We read with interest the article by Heitmiller and colleagues (11 detailing their experience with a patient who had a benign schwannoma of the right intrathoracic vagus nerve, and their review of the literature which showed this to be a rare neurogenic tumor of the thorax. Recently, a 38-year-old man came to our attention for evaluation and treatment of a 4.0-cm mass in the left posterior mediastinum adjacent to the aortic knob, which was detected on routine chest roentgenogram (Fig 1). A history of blunt chest
Fig I . Standard posteroanterior chest roentgenogram ruith an abnormal 4-on density adjacent to the aortic knob.
Ann Thorac Surg i991;52: 1368-71
CORRESPONDENCE
1371
the recurrent laryngeal nerve. The recurrent laryngeal nerve was dissected free, and the mass was excised along with a segment of the vagus nerve. Pathologically, the tumor was a benign schwannoma. The patient's recovery was uneventful. This case was interesting to us for two reasons: (1)the rarity of a schwannoma taking origin from the intrathoracic vagus nerve and (2) the location of the tumor adjacent to the aortic knob in conjunction with a history of chest trauma that aroused suspicion that the mass was a pseudoaneurysm, which could not be excluded by computed tomographic scan. A magnetic resonance imaging scan, however, clearly showed the mass to be distinct and separate from the aorta and, therefore, not of vascular origin.
William A. Walker, M D Department of Surgery UT-Memphis 956 Court Ave Memphis, T N 38163 A
Frank E. Maguire, M D Pulmona ry Medicine Naval Hospital Sun Diego San Diego, C A 92134
Reference 1. Heitmiller W, Labs JD, Lipsetl PA. Vagal schwannoma. Ann Thorac Surg 1990;50:811-3.
Reply
To the Editor:
B Fig 2. Magnetic resonance images demonstrating a well-delineated mass adjacent to the aortic arch, with a discrete tissue plane between the lesion and the aorta.
trauma 1 year earlier aroused suspicion that this might be a pseudoaneurysm of the descending aorta, which could not be excluded by contrasted computed tomographic scan of the chest. A magnetic resonance imaging scan clearly demonstrated the mass to be distinct from the aorta. The mass did not contain signal compatible with extracellular methemoglobin or hemosiderin, excluding a vascular origin (Fig 2). The patient was explored through a left posterolateral thoracotomy, where a firm, 4.0 x 4.0 x 3.5-cm mass was found. The mass originated from the vagus nerve just distal to
Recently there have been several reports on intrathoracic vagal schwannomas, which have focused attention on these unusual tumors [l, 21. The case presented by Drs Walker and Maguire represents another example and underscores the principal characteristics of these tumors, which are as follows: (1)they are rare, (2) the tumors are invariably discovered on routine chest roentgenograms and produce no symptoms, (3) tumors may occur anywhere along the intrathoracic vagus nerve, and depending on their size and location, may radiographically mimic other intrathoracic pathology, (4) thoracotomy is necessary for definitive diagnosis and treatment, (5) the vast majority of these tumors are benign, and (6) complete resection is curative.
Richard F . Heitmiller, M D Department of Thoracic Surgery ]ohm Hopkins Hospital Osler 624, 600 N Wolfe St Baltimore, M D 21205
References 1. Dabir RR, Piccione W Jr, Kittle CF. Intrathoracic tumors of the vagus nerve. Ann Thorac Surg 1990;50:494-7. 2. Heitmiller W, Labs JD, Lipsett PA. Vagal schwannoma. Ann Thorac Surg 1990;50:811-3.
Ann Thorac Surg 1991:5213&71
CORRESPONDENCE
judge, but I commend it as a possibility to be considered in the various situations that we have described in our report. I agree entirely with Dr Santos about the acute rupture and that our method of internal drainage is unlikely to be rewarded with success. I congratulate him on his technique of pleural irrigation, which should be considered in the presence of gross mediastinal sepsis. Our personal preference is for early ruptures to be repaired directly, but in patients in whom the rupture is more than 24 hours old, as is very often the case, we have opted for cervical esophagostomy, subtotal esophageal resection, and gastrostomy to be followed at a later date by reconstituting swallowing with a gastric pull-up. Clearly there are patients who at the time of presentation are not fit to withstand such a major operation, and Dr Santos’ alternative could be life saving and buy time until definitive treatment is more appropriate.
K . M . Pagliero, FRCS Royal Devon G. Exeter Hospital Barrack Rd Exeter EX2 SDW England
Retrograde Disc Escape in a Harken Mitral Valve Prosthesis 21 Years After Implantation To the Editor: The Harken discoid mitral valve, introduced in 1967 [l]and available in three sizes (small, medium, and large), consisted of a barium-impregnated silicone rubber disc inside a highly polished titanium cage, with two metallic struts crossing each other at 90-degree angles. Scarce data are published on mechanical dysfunctions of this valve or its long-term performance. We have seen a rare type of dysfunction very late (21 years) after implantation. A 54-year-old woman received a Harken medium-size mitral valve in 1969 for severe mitral regurgitation early after attempted redo mitral commissurotomy. In 1981 she had a stroke (left hemiparesis) followed by complete neurological recovery. She remained in New York Heart Association class I or 11 up to May 1990 when sudden respiratory distress was noted. On admission the patient was in pulmonary edema and no prosthetic sounds were heard; she was intubated, and mechanical ventilation and inotropic support were started. Echocardiography suggested mitral valve thrombosis and massive tricuspid regurgitation. Thrombus lysis with anisoylated plasminogen streptokinase activator complex was attempted and followed by some clinical improvement; the physician caring for the patient reported reappearance of prosthetic valve sounds. Later on, the clinical status of the patient worsened and high fever appeared. A new color echocardiogram and Doppler study suggested mild mitral and moderate tricuspid regurgitation. Hours later giant V waves were noted in the capillary wedge pressure and a new echocardiogram showed massive mitral regurgitation. At operation the left atrium was partially covered by mural thrombus with some areas of calcification, and the disc of the prosthesis was found freely floating in the atrium. On closer examination the disc had a nick in one of the borders, but no thrombus or any other macroscopic abnormality was detected. The cage of the prosthesis was well incorporated into the annulus, without any signs of thrombosis, leak, or infection; no wear of the seat was identified. The cage was explanted and a 29-mm St. Jude Medical valve prosthesis was implanted with standard techniques. Continuous hemodialysis for established renal failure was performed during bypass. Respiratory, hepatic, and renal failure requiring hemodialysis, as well as severe neurological dysfunction, complicated the first postoperative days, but the patient subsequently improved and was finally
discharged in good condition. Six months after operation she was leading an active life, again in functional class 11. Discoid valve prostheses, mainly used in the late 1960s and early 1970s, showed vulnerability to catastrophic failure and high rates of thromboembolism as their most important weaknesses. Retrograde disc escape into the left atrium is a rare complication of discoid valves, previously reported [Z] in a patient with a Cross-Jones mitral valve prosthesis. The echocardiographic sequence of events in our patient, suggesting impaction of the disc eventually leading to retrograde disc escape, seems rather unusual. Although valve thrombosis may be more frequent than disc variance in patients with discoid valve prostheses [3], we now believe that urgent operation instead of thrombolysis should be performed in a patient with signs of obstruction of a Harken valve prostheses if the diagnosis of disc variance cannot be ruled out.
Eduardo Otero-Coto, M D , PhD Angel Silla, M D luan A. Casillas, M D , PhD Services of Cardiovascular Surgery and lntensive Medicine Hospital de Alicante CIMaestro Alonso 109 Alicante 03010, Spain
References 1. Harken DE, Matloff JM, Zuckerman W, Chaux A. A new mitral valve. J Thorac Cardiovasc Surg 1968;55:369-78. 2. Lukacs L, Lonyai T. A unique malfunction of Cross-Jones Mitral valve prosthesis. J Cardiovasc Surg 1980;21:954. 3. Hylen JC. Mechanical malfunction and thrombosis of prosthetic heart valves. Am J Cardiol 1972;30:396404.
Vagal Schwannoma To the Editor: We read with interest the article by Heitmiller and colleagues (11 detailing their experience with a patient who had a benign schwannoma of the right intrathoracic vagus nerve, and their review of the literature which showed this to be a rare neurogenic tumor of the thorax. Recently, a 38-year-old man came to our attention for evaluation and treatment of a 4.0-cm mass in the left posterior mediastinum adjacent to the aortic knob, which was detected on routine chest roentgenogram (Fig 1). A history of blunt chest
Fig I . Standard posteroanterior chest roentgenogram ruith an abnormal 4-on density adjacent to the aortic knob.
Ann Thorac Surg i991;52: 1368-71
CORRESPONDENCE
1371
the recurrent laryngeal nerve. The recurrent laryngeal nerve was dissected free, and the mass was excised along with a segment of the vagus nerve. Pathologically, the tumor was a benign schwannoma. The patient's recovery was uneventful. This case was interesting to us for two reasons: (1)the rarity of a schwannoma taking origin from the intrathoracic vagus nerve and (2) the location of the tumor adjacent to the aortic knob in conjunction with a history of chest trauma that aroused suspicion that the mass was a pseudoaneurysm, which could not be excluded by computed tomographic scan. A magnetic resonance imaging scan, however, clearly showed the mass to be distinct and separate from the aorta and, therefore, not of vascular origin.
William A. Walker, M D Department of Surgery UT-Memphis 956 Court Ave Memphis, T N 38163 A
Frank E. Maguire, M D Pulmona ry Medicine Naval Hospital Sun Diego San Diego, C A 92134
Reference 1. Heitmiller W, Labs JD, Lipsetl PA. Vagal schwannoma. Ann Thorac Surg 1990;50:811-3.
Reply
To the Editor:
B Fig 2. Magnetic resonance images demonstrating a well-delineated mass adjacent to the aortic arch, with a discrete tissue plane between the lesion and the aorta.
trauma 1 year earlier aroused suspicion that this might be a pseudoaneurysm of the descending aorta, which could not be excluded by contrasted computed tomographic scan of the chest. A magnetic resonance imaging scan clearly demonstrated the mass to be distinct from the aorta. The mass did not contain signal compatible with extracellular methemoglobin or hemosiderin, excluding a vascular origin (Fig 2). The patient was explored through a left posterolateral thoracotomy, where a firm, 4.0 x 4.0 x 3.5-cm mass was found. The mass originated from the vagus nerve just distal to
Recently there have been several reports on intrathoracic vagal schwannomas, which have focused attention on these unusual tumors [l, 21. The case presented by Drs Walker and Maguire represents another example and underscores the principal characteristics of these tumors, which are as follows: (1)they are rare, (2) the tumors are invariably discovered on routine chest roentgenograms and produce no symptoms, (3) tumors may occur anywhere along the intrathoracic vagus nerve, and depending on their size and location, may radiographically mimic other intrathoracic pathology, (4) thoracotomy is necessary for definitive diagnosis and treatment, (5) the vast majority of these tumors are benign, and (6) complete resection is curative.
Richard F . Heitmiller, M D Department of Thoracic Surgery ]ohm Hopkins Hospital Osler 624, 600 N Wolfe St Baltimore, M D 21205
References 1. Dabir RR, Piccione W Jr, Kittle CF. Intrathoracic tumors of the vagus nerve. Ann Thorac Surg 1990;50:494-7. 2. Heitmiller W, Labs JD, Lipsett PA. Vagal schwannoma. Ann Thorac Surg 1990;50:811-3.