Angioplastic Repair of a Ruptured Pulmonary Artery Aneurysm Noel H. Fishman, M.D., Edward W. Miller, M.D., a n d Thomas A. Freed, M.D. ABSTRACT A 28-year-old woman had a ruptured solitary pulmonary arterial aneurysm which was successfully treated by pericardial patch graft. The etiology of the aneurysm could not be determined although the patient had had several episodes of blunt chest trauma in the past. Unusual aspects of this case include: location of the aneurysm in the intermediate portion of the left pulmonary artery within the major intralobar fissure, intrapleural rupture, preoperative diagnosis by pulmonary angiography, and an incidentally discovered histopathological abnormality of the aneurysm itself for which no satisfactory explanation has been found.
Pulmonary artery aneurysms are extremely rare and are seldom diagnosed during life [6]. The aneurysms tend to occur centrally, with dilatation and degeneration of the pulmonary trunk and main pulmonary arteries [2,61, or peripherally, as single or multiple dilatations of small intraparenchymal arteries [4, 111. Most of these aneurysms are intact at postmortem examination, but occasional intrabronchial rupture has been reported. Improved techniques now make clinical diagnosis and surgical management feasible [9, 12, 13, 191. This report describes the presentation and management of an atypical pulmonary artery aneurysm. A previously vigorous 28-year-old woman was transferred to Moffitt Hospital, University of California, San Francisco, on September 8, 1973, for operative management of a ruptured solitary pulmonary artery aneurysm. The patient had had an intermittent cough associated with allergy to cat fur for many years. In 1968 she From the Department of Surgery, University of California, San Francisco, School of Medicine, and the Departments of Surgery and Radiology, Marin General Hospital, San Rafael, CA. Accepted for publication June 25, 1975. Address reprint requests to Dr. Fishman, Department of Surgery, University of California, San Francisco, School of Medicine, San Francisco, CA 94143. 184
had been hospitalized following a forceful steering wheel injury to her chest but sustained no roentgenographically demonstrable injury. She had two other traumatic episodes following this, a fall from a horse and a fall from water skis, which were associated with only mild neuromuscular sequelae. One year prior to the present admission the patient began to experience occasional paroxysms of coughing associated with a choking sensation and the production of copious amounts of watery sputum. During a paroxysm of coughing on the day of admission the patient lost consciousness and was pulseless. Prompt intravascular volume replacement at another hospital successfully controlled the profound hypotension. A chest roentgenogram showed complete opacification of the left hemithorax (Fig 1A). Following tube thoracostomy drainage of 1,500 ml of blood, a second chest roentgenogram demonstrated a rounded hilar mass approximately 4 cm in diameter (Fig 1B). An angiogram showed the mass to be an aneurysm arising from the intermediate segment of the left pulmonary artery (Fig 2). Review of a chiropractic full-body roentgenogram taken one month prior to admission showed a left hilar mass about 2 cm in diameter. On admission to the University of California Hospital the patient was alert with normal vital signs and in no distress. Breath sounds on the left side of the chest were decreased. The hemoglobin was 8 gm per 100 ml. Other laboratory tests and the electrocardiogram were normal. A left thoracotomy was performed shortly after admission with the cardiopulmonary bypass apparatus on standby alert. The proximal portion of the left pulmonary artery was normal in size and consistency. The wall was not thickened, the pressure was qualitatively normal within the vessel, and no thrills or plaques were palpable. A pulsatile, thin-walled aneurysm 4 cm in diameter and widely based on the anterior surface of the left pulmonary artery projected into a
185 Case Report: Fishman et al: Repair of Ruptured PA Aneurysm
A
B
Fig 1. ( A )Chest roentgenogram taken shortly after resuscitation from profound shock. Note opacification of the left hemithorax and deviation of the mediastinum toward the right. ( B ) Chest roentgenogram taken following tube thoracostomy and drainage of hemothoraxshows a left hilar mass.
well-developed major interlobar fissure (Fig 3A). Small areas of the upper and lower lobes were adherent to the sides of the aneurysm. A blackened area on the free outer surface of the aneurysm marked the region from which hemorrhage had occurred. After the aneurysm was opened, a large, clearly demarcated defect could be seen that extended into the proximal portions of several segmental arteries of both lobes (Fig 3B). Hemostatic control of the lung was obtained by applying tourniquets around the pulmonary artery and pulmonary veins. The aneurysm was resected completely except in areas of pleural adherence. The arterial wall was reconstructed with a free pericardial graft cut to fit precisely into the defect (Fig 3C). The postoperative course was uncomplicated. Microscopical examination of the resected tissues showed large numbers of mitotic nuclear figures, which prompted the tentative diagnosis of a poorly differentiated malignancy by some of the pathologists who reviewed the material. The possibility of a malignant mesothelioma or choriocarcinoma was considered. The benign appearance of the tissues grossly and the absence of tumorlike cells in adjacent lymph nodes prompted us to elect a course of clinical observation. Over the subsequent 18 months there has been no roentgenographic or clinical evidence of aneurysm recurrence or development of an intrathoracic mass. In the interim, transient and
Fig2. Selective left pulmonary angiogram demonstrating an aneurysm 4 cm in diameter arising from the intermediate portion of the artery.
186 The Annals of Thoracic Surgery Vol 21 No 2 February 1976
Fig3. Operative findings and method of repair. ( A ) Aneurysm in situ within the major fissure of the left lung. (B)Arterial wall defect after excision of the aneurysm showing extensions into some of the segmental arteries. Small portions of the aneurysm remain on adjacent lobar pleural surfaces. (C) Technique of pericardial patch angioplasty.
/
intermittent coughing has persisted and has become associated with occasional exertional dyspnea and wheezing, for which the patient is now being treated with inhaled bronchodilators and oral antihistamines. The patient was recently reevaluated at this hospital. Except for an eosinophilia of 9%, the laboratory data were entirely normal. A pulmonary angiogram showed a normal pulmonary arterial configuration in the area of surgical reconstruction. Pulmonary artery and pulmonary capillary wedge pressures were normal.
Comment Location of an aneurysm limited to the free wall of one of the intermediate pulmonary arteries is very unusual. In 1884 Kidd [8] reported a large series of patients who died from chronic pulmonary tuberculosis, 10% of whom had solitary peripheral pulmonary artery aneurysms. Many other series of both solitary and multiple peripheral pulmonary artery aneurysms have been published since then, mostly in association with chronic pulmonary tuberculosis [l, 5, 131 although mycotic aneurysms secondary to pulmonary infections or endocarditis have also been described [ill.
Aneurysms of the pulmonary trunk, bifurcation, and proximal main pulmonary arteries have been reviewed extensively [3, 61. The rate of occurrence is approximately once in every 14,000 postmortem examinations [6]. Most of these have been associated with a positive serological test for syphilis (gummas are very rare in these lesions [ll]) or with cardiovascular disease, either congenital or acquired. In the Mayo Clinic series, 21% of the patients also had a patent ductus arteriosus while another 25% had a ventricular septal defect, atrial septal defect, aortic stenosis, mitral stenosis, or pulmonary fibrosis [6]. None of these aneurysms was apparently related to tuberculosis or trauma. The clinical findings included cough, cyanosis, dyspnea, and electrocardiographic abnormalities suggestive of right ventricular hypertrophy. The common element seems to have been the distending effect of chronically elevated pulmonary artery pressure. Arteriosclerotic plaques are frequently seen in centrally located aneurysms, and dissection secondary to cystic medial necrosis has been described [2,15,16]. Penetrating chest injury, but not blunt chest trauma, has been cited as a cause of pulmonary artery aneurysm in a few patients [MI. The association of a pulmonary artery aneurysm with hemothorax is unusual; most aneurysms are found intact at postmortem examination. While a small percentage of pulmonary artery aneurysms are seen with exsanguinating hemorrhage, the bleeding is usually intrabronchial [6]. Recently, free rupture of the ascending aorta from the erosive effects of an adjacent main pulmonary artery aneurysm U41 and free rupture of a saccular aneurysm in a lower lobe branch of the left pulmonary artery [71 have been reported. The latter case was associated with pulmonary hypertension from recurrent thromboembolism and degenerative changes in the wall of the pulmonary artery.
187 Case Report: Fishman et al: Repair of Ruptured PA Aneurysm
In the patient presented in this report, trauma may have been the etiology. Pulmonary hypertension, endocarditis, tuberculosis, and other pulmonary infections were all excluded by clinical and pathological examination. Traumatic aneurysms occur in systemic arteries as a result of either penetrating or nonpenetrating injuries. False aneurysms of the descending aorta have occurred following episodes of blunt chest trauma similar to those experienced by this patient. The absence of enveloping pulmonary parenchyma in this completely developed major fissure may account for the aneurysmal dilatation in the face of normal pulmonary artery pressure. The absence of pulmonary hypertension may have been responsible for the hemorrhage being spontaneously contained temporarily following rupture of the aneurysm in this patient, which in turn allowed time for diagnostic studies and surgical repair. Patch grafting was a clear alternative to pneumonectomy in this patient because the aneurysm had not expanded into the pulmonary tissue. Either Dacron or pericardium could have been used satisfactorily in the repair. Both materials have been used extensively within the heart and pulmonary arteries and have functioned well [lo, 171. Pericardium was chosen in this case because it is relatively more compliant and hemostatic than Dacron, particularly when sewn into an irregularly shaped defect in the thinwalled pulmonary artery. When reconstructed, the pulmonary artery had a normal configuration (see Fig 3), and it still does. Nothing about the gross appearance of this false aneurysm remotely suggested the presence of tumor of any type. The wall of the aneurysm was evenly thin throughout and, although adherent to the pleura, was not grossly or microscopically invasive. Adjacent small lymph nodes contained no abnormal cells. The bizarre histopathological appearance of this aneurysm is described here primarily for future reference and review. A definitive cellular diagnosis has not been forthcoming. Several of the pathologists who reviewed the slides believed this to be an intense inflammatory reaction secondary to acute distention and hemorrhage. Others considered the anaplastic appearing cells
to be malignant, and their opinions varied as to cell type. Possible pathological diagnoses included malignant mesothelioma and choriocarcinoma, neither of which is surgically curable. Malignant mesothelioma is usually a disease of multicentric origin in the pleura. There was no evidence of pleural tumor or thickening at thoracotomy. Choriocarcinoma also does not originate as a primary solitary tumor of the lung. In the event that these bizarre histological findings do represent some undefined but purely localized tumor, the location of the aneurysm, so well separated from the central mediastinal structures, has made it ideal for continuing roentgenographic surveillance. During the subsequent 18 months no evidence of local recurrence or mediastinal involvement has developed, and further observation is being continued.
References 1. Auerbach 0: Pathology and pathogenesis of pulmonary arterial aneurysm in tuberculous cavities. Am Rev Tuberc 39:99, 1939 2. Best J: Dissecting aneurysm of the pulmonary artery with multiple cardiovascular abnormalities and pulmonary hypertension. Med J Aust 2:1129, 1967 3. Boyd LJ, McGavack TH: Aneurysm of the pulmonary artery: a review of literature and report of two new cases. Am Heart J 18:562, 1939 4. Calenoff L: Multiple mycotic pulmonary artery aneurysms. Am J Roentgen01 91:379, 1964 5. Charlton RW, DuPlessis LA: Multiple pulmonary artery aneurysms. Thorax 16:364, 1961 6. Deterling RA Jr, Clagett OT: Aneurysm of the pulmonary artery: review of the literature and report of a case. Am Heart J 34:471, 1947 7. Imahori S, Montes M, Brennan JC: Ruptured aneurysm of pulmonary artery. Am Rev Resp Dis 97:122, 1968 8. Kidd P: Unusual cases of pulmonary aneurysm. Trans Pathol SOCLond 35:98, 1884 9. Konhaus CH, Kunkel PA Jr: Aneurysm of a pulmonary artery: report of a case in which treatment was surgical. Ann Surg 142:997, 1955 10. Lam CR, McIntyre RE: Prosthetic replacement of the pulmonary artery for the preservation of lung tissue. Ann Thorac Surg 9:474, 1970 11. Lillian M: Multiple pulmonary artery aneurysms: endarteritis of ductus arteriosus and congenital pulmonary cysts. Am J Med 7:280, 1949 12. MacKenzie DA, Clagett OT: Unusual aneurysm
188 The Annals of Thoracic Surgery Vol 21 No 2 February 1976
of a pulmonary artery: report of case in which treatment was surgical. J Thorac Surg 25:524, 1953 13. Monchik J, Wilkins EW: Solitary aneurysm of the middle lobe artery: a case report and review of solitary peripheral pulmonary artery aneurysms. Ann Thorac Surg 17:496, 1974 14. Placak B, Jech J: Aneurysm of the pulmonary artery. Int Surg 55:343, 1971 15. Ravines HT: Dissecting hematomas of intrapulmonary arteries in a case of pulmonary hypertension associated with patent ductus arteriosus. J Thorac Cardiovasc Surg 39:760, 1960
16. Shilkin KB, Low LP, Chen BTM: Dissecting aneurysm of the pulmonary artery. J Pathol98:25, 1969 17. Shumacker HB, Mandelbaum I: Prosthetic grafts for replacement of the pulmonary artery. J Thorac Cardiovasc Surg 55:663, 1968 18. Symbas I", Scott HW Jr: Traumatic aneurysm of the pulmonary artery. J Thorac Cardiovasc Surg 45:645, 1963 19. Williams TE Jr, Schiller M, Craenen J, et al: Pulmonary artery aneurysm: successful excision and replacement of the main pulmonary artery. J Thorac Cardiovasc Surg 62:63, 1971
Pulmonary artery aneurysms are extremely rare and are seldom diagnosed during life [6]. The aneurysms tend to occur centrally, with dilatation and degeneration of the pulmonary trunk and main pulmonary arteries [2,61, or peripherally, as single or multiple dilatations of small intraparenchymal arteries [4, 111. Most of these aneurysms are intact at postmortem examination, but occasional intrabronchial rupture has been reported. Improved techniques now make clinical diagnosis and surgical management feasible [9, 12, 13, 191. This report describes the presentation and management of an atypical pulmonary artery aneurysm. A previously vigorous 28-year-old woman was transferred to Moffitt Hospital, University of California, San Francisco, on September 8, 1973, for operative management of a ruptured solitary pulmonary artery aneurysm. The patient had had an intermittent cough associated with allergy to cat fur for many years. In 1968 she From the Department of Surgery, University of California, San Francisco, School of Medicine, and the Departments of Surgery and Radiology, Marin General Hospital, San Rafael, CA. Accepted for publication June 25, 1975. Address reprint requests to Dr. Fishman, Department of Surgery, University of California, San Francisco, School of Medicine, San Francisco, CA 94143. 184
had been hospitalized following a forceful steering wheel injury to her chest but sustained no roentgenographically demonstrable injury. She had two other traumatic episodes following this, a fall from a horse and a fall from water skis, which were associated with only mild neuromuscular sequelae. One year prior to the present admission the patient began to experience occasional paroxysms of coughing associated with a choking sensation and the production of copious amounts of watery sputum. During a paroxysm of coughing on the day of admission the patient lost consciousness and was pulseless. Prompt intravascular volume replacement at another hospital successfully controlled the profound hypotension. A chest roentgenogram showed complete opacification of the left hemithorax (Fig 1A). Following tube thoracostomy drainage of 1,500 ml of blood, a second chest roentgenogram demonstrated a rounded hilar mass approximately 4 cm in diameter (Fig 1B). An angiogram showed the mass to be an aneurysm arising from the intermediate segment of the left pulmonary artery (Fig 2). Review of a chiropractic full-body roentgenogram taken one month prior to admission showed a left hilar mass about 2 cm in diameter. On admission to the University of California Hospital the patient was alert with normal vital signs and in no distress. Breath sounds on the left side of the chest were decreased. The hemoglobin was 8 gm per 100 ml. Other laboratory tests and the electrocardiogram were normal. A left thoracotomy was performed shortly after admission with the cardiopulmonary bypass apparatus on standby alert. The proximal portion of the left pulmonary artery was normal in size and consistency. The wall was not thickened, the pressure was qualitatively normal within the vessel, and no thrills or plaques were palpable. A pulsatile, thin-walled aneurysm 4 cm in diameter and widely based on the anterior surface of the left pulmonary artery projected into a
185 Case Report: Fishman et al: Repair of Ruptured PA Aneurysm
A
B
Fig 1. ( A )Chest roentgenogram taken shortly after resuscitation from profound shock. Note opacification of the left hemithorax and deviation of the mediastinum toward the right. ( B ) Chest roentgenogram taken following tube thoracostomy and drainage of hemothoraxshows a left hilar mass.
well-developed major interlobar fissure (Fig 3A). Small areas of the upper and lower lobes were adherent to the sides of the aneurysm. A blackened area on the free outer surface of the aneurysm marked the region from which hemorrhage had occurred. After the aneurysm was opened, a large, clearly demarcated defect could be seen that extended into the proximal portions of several segmental arteries of both lobes (Fig 3B). Hemostatic control of the lung was obtained by applying tourniquets around the pulmonary artery and pulmonary veins. The aneurysm was resected completely except in areas of pleural adherence. The arterial wall was reconstructed with a free pericardial graft cut to fit precisely into the defect (Fig 3C). The postoperative course was uncomplicated. Microscopical examination of the resected tissues showed large numbers of mitotic nuclear figures, which prompted the tentative diagnosis of a poorly differentiated malignancy by some of the pathologists who reviewed the material. The possibility of a malignant mesothelioma or choriocarcinoma was considered. The benign appearance of the tissues grossly and the absence of tumorlike cells in adjacent lymph nodes prompted us to elect a course of clinical observation. Over the subsequent 18 months there has been no roentgenographic or clinical evidence of aneurysm recurrence or development of an intrathoracic mass. In the interim, transient and
Fig2. Selective left pulmonary angiogram demonstrating an aneurysm 4 cm in diameter arising from the intermediate portion of the artery.
186 The Annals of Thoracic Surgery Vol 21 No 2 February 1976
Fig3. Operative findings and method of repair. ( A ) Aneurysm in situ within the major fissure of the left lung. (B)Arterial wall defect after excision of the aneurysm showing extensions into some of the segmental arteries. Small portions of the aneurysm remain on adjacent lobar pleural surfaces. (C) Technique of pericardial patch angioplasty.
/
intermittent coughing has persisted and has become associated with occasional exertional dyspnea and wheezing, for which the patient is now being treated with inhaled bronchodilators and oral antihistamines. The patient was recently reevaluated at this hospital. Except for an eosinophilia of 9%, the laboratory data were entirely normal. A pulmonary angiogram showed a normal pulmonary arterial configuration in the area of surgical reconstruction. Pulmonary artery and pulmonary capillary wedge pressures were normal.
Comment Location of an aneurysm limited to the free wall of one of the intermediate pulmonary arteries is very unusual. In 1884 Kidd [8] reported a large series of patients who died from chronic pulmonary tuberculosis, 10% of whom had solitary peripheral pulmonary artery aneurysms. Many other series of both solitary and multiple peripheral pulmonary artery aneurysms have been published since then, mostly in association with chronic pulmonary tuberculosis [l, 5, 131 although mycotic aneurysms secondary to pulmonary infections or endocarditis have also been described [ill.
Aneurysms of the pulmonary trunk, bifurcation, and proximal main pulmonary arteries have been reviewed extensively [3, 61. The rate of occurrence is approximately once in every 14,000 postmortem examinations [6]. Most of these have been associated with a positive serological test for syphilis (gummas are very rare in these lesions [ll]) or with cardiovascular disease, either congenital or acquired. In the Mayo Clinic series, 21% of the patients also had a patent ductus arteriosus while another 25% had a ventricular septal defect, atrial septal defect, aortic stenosis, mitral stenosis, or pulmonary fibrosis [6]. None of these aneurysms was apparently related to tuberculosis or trauma. The clinical findings included cough, cyanosis, dyspnea, and electrocardiographic abnormalities suggestive of right ventricular hypertrophy. The common element seems to have been the distending effect of chronically elevated pulmonary artery pressure. Arteriosclerotic plaques are frequently seen in centrally located aneurysms, and dissection secondary to cystic medial necrosis has been described [2,15,16]. Penetrating chest injury, but not blunt chest trauma, has been cited as a cause of pulmonary artery aneurysm in a few patients [MI. The association of a pulmonary artery aneurysm with hemothorax is unusual; most aneurysms are found intact at postmortem examination. While a small percentage of pulmonary artery aneurysms are seen with exsanguinating hemorrhage, the bleeding is usually intrabronchial [6]. Recently, free rupture of the ascending aorta from the erosive effects of an adjacent main pulmonary artery aneurysm U41 and free rupture of a saccular aneurysm in a lower lobe branch of the left pulmonary artery [71 have been reported. The latter case was associated with pulmonary hypertension from recurrent thromboembolism and degenerative changes in the wall of the pulmonary artery.
187 Case Report: Fishman et al: Repair of Ruptured PA Aneurysm
In the patient presented in this report, trauma may have been the etiology. Pulmonary hypertension, endocarditis, tuberculosis, and other pulmonary infections were all excluded by clinical and pathological examination. Traumatic aneurysms occur in systemic arteries as a result of either penetrating or nonpenetrating injuries. False aneurysms of the descending aorta have occurred following episodes of blunt chest trauma similar to those experienced by this patient. The absence of enveloping pulmonary parenchyma in this completely developed major fissure may account for the aneurysmal dilatation in the face of normal pulmonary artery pressure. The absence of pulmonary hypertension may have been responsible for the hemorrhage being spontaneously contained temporarily following rupture of the aneurysm in this patient, which in turn allowed time for diagnostic studies and surgical repair. Patch grafting was a clear alternative to pneumonectomy in this patient because the aneurysm had not expanded into the pulmonary tissue. Either Dacron or pericardium could have been used satisfactorily in the repair. Both materials have been used extensively within the heart and pulmonary arteries and have functioned well [lo, 171. Pericardium was chosen in this case because it is relatively more compliant and hemostatic than Dacron, particularly when sewn into an irregularly shaped defect in the thinwalled pulmonary artery. When reconstructed, the pulmonary artery had a normal configuration (see Fig 3), and it still does. Nothing about the gross appearance of this false aneurysm remotely suggested the presence of tumor of any type. The wall of the aneurysm was evenly thin throughout and, although adherent to the pleura, was not grossly or microscopically invasive. Adjacent small lymph nodes contained no abnormal cells. The bizarre histopathological appearance of this aneurysm is described here primarily for future reference and review. A definitive cellular diagnosis has not been forthcoming. Several of the pathologists who reviewed the slides believed this to be an intense inflammatory reaction secondary to acute distention and hemorrhage. Others considered the anaplastic appearing cells
to be malignant, and their opinions varied as to cell type. Possible pathological diagnoses included malignant mesothelioma and choriocarcinoma, neither of which is surgically curable. Malignant mesothelioma is usually a disease of multicentric origin in the pleura. There was no evidence of pleural tumor or thickening at thoracotomy. Choriocarcinoma also does not originate as a primary solitary tumor of the lung. In the event that these bizarre histological findings do represent some undefined but purely localized tumor, the location of the aneurysm, so well separated from the central mediastinal structures, has made it ideal for continuing roentgenographic surveillance. During the subsequent 18 months no evidence of local recurrence or mediastinal involvement has developed, and further observation is being continued.
References 1. Auerbach 0: Pathology and pathogenesis of pulmonary arterial aneurysm in tuberculous cavities. Am Rev Tuberc 39:99, 1939 2. Best J: Dissecting aneurysm of the pulmonary artery with multiple cardiovascular abnormalities and pulmonary hypertension. Med J Aust 2:1129, 1967 3. Boyd LJ, McGavack TH: Aneurysm of the pulmonary artery: a review of literature and report of two new cases. Am Heart J 18:562, 1939 4. Calenoff L: Multiple mycotic pulmonary artery aneurysms. Am J Roentgen01 91:379, 1964 5. Charlton RW, DuPlessis LA: Multiple pulmonary artery aneurysms. Thorax 16:364, 1961 6. Deterling RA Jr, Clagett OT: Aneurysm of the pulmonary artery: review of the literature and report of a case. Am Heart J 34:471, 1947 7. Imahori S, Montes M, Brennan JC: Ruptured aneurysm of pulmonary artery. Am Rev Resp Dis 97:122, 1968 8. Kidd P: Unusual cases of pulmonary aneurysm. Trans Pathol SOCLond 35:98, 1884 9. Konhaus CH, Kunkel PA Jr: Aneurysm of a pulmonary artery: report of a case in which treatment was surgical. Ann Surg 142:997, 1955 10. Lam CR, McIntyre RE: Prosthetic replacement of the pulmonary artery for the preservation of lung tissue. Ann Thorac Surg 9:474, 1970 11. Lillian M: Multiple pulmonary artery aneurysms: endarteritis of ductus arteriosus and congenital pulmonary cysts. Am J Med 7:280, 1949 12. MacKenzie DA, Clagett OT: Unusual aneurysm
188 The Annals of Thoracic Surgery Vol 21 No 2 February 1976
of a pulmonary artery: report of case in which treatment was surgical. J Thorac Surg 25:524, 1953 13. Monchik J, Wilkins EW: Solitary aneurysm of the middle lobe artery: a case report and review of solitary peripheral pulmonary artery aneurysms. Ann Thorac Surg 17:496, 1974 14. Placak B, Jech J: Aneurysm of the pulmonary artery. Int Surg 55:343, 1971 15. Ravines HT: Dissecting hematomas of intrapulmonary arteries in a case of pulmonary hypertension associated with patent ductus arteriosus. J Thorac Cardiovasc Surg 39:760, 1960
16. Shilkin KB, Low LP, Chen BTM: Dissecting aneurysm of the pulmonary artery. J Pathol98:25, 1969 17. Shumacker HB, Mandelbaum I: Prosthetic grafts for replacement of the pulmonary artery. J Thorac Cardiovasc Surg 55:663, 1968 18. Symbas I", Scott HW Jr: Traumatic aneurysm of the pulmonary artery. J Thorac Cardiovasc Surg 45:645, 1963 19. Williams TE Jr, Schiller M, Craenen J, et al: Pulmonary artery aneurysm: successful excision and replacement of the main pulmonary artery. J Thorac Cardiovasc Surg 62:63, 1971
