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Traumatic rupture of the ascending aorta and aortic valve following blunt chest trauma
Traumatic rupture of the ascending aorta and aortic valve following blunt chest trauma Traumatic rupture of the aorta at the level of the isthmus is a well-recognized injury following blunt chest trauma. By contrast, rupture of the ascending aorta and of the aortic valve in a road traffic accident is rare and does not appear to have been previously reported. The occurrence of such an injury in a 56-year-old man involved in a road traffic accident is reported. The diagnosis was made preoperatively following aortography and successful surgical correction involved aortic valve replacement with resection and grafting of the damaged area of the ascending aorta. The probable mechanisms involved in the production of this unusual injury are discussed.
Kelvin P. Charles, M . B . , Kenneth G. Davidson, F.R.C.S., Hugh Miller, M.B., and Philip K. Caves, F . R . C . S . , Edinburgh, Scotland
-L raumatic rupture of the thoracic aorta at the level of the ligamentum arteriosum is a well-recognized injury following severe blunt chest injury, particularly of the deacceleration type. 10, 15, 17, 24, 26, 28 Other injuries of the chest, head, abdomen, and l i m b s 6 , 7 " 1 0 ' 1 3 ' 1 5 , 2 0 , 2 5 ' 27 are commonly associated. Avulsion of the major branches of the arch of the thoracic aorta can also occur. 14, 22 By contrast, rupture of the ascending aorta with or without aortic valve damage following blunt chest trauma is rare and has been reported previously only in a patient with prior dissection of the descending thoracic aorta. 4 This paper reports successful surgical correction in a patient who suffered traumatic rupture of the ascending aorta and the aortic valve in a road traffic accident. Case history A 56-year-old railwayman was admitted to hospital as an emergency case in April, 1975, following a road traffic accident. The car which he had been driving had collided head-on with a tree while traveling at approximately 35 m.p.h. He was not wearing a seat belt. At the time of admission the patient was semiconscious and responding appropriately to painful stimuli. The only external From the University Department of Clinical Surgery and the Department of Cardiovascular Surgery, Royal Infirmary, Edinburgh, Scotland. Received for publication March 30, 1976. Accepted for publication Aug. 31, 1976. Address for reprints: Prof. Philip K. Caves, F.R.C.S., Department of Cardiothoracic Surgery, Royal Infirmary, Glasgow, Scotland.
208
evidence of injury was a laceration over his left eye. X-rays of his skull, cervical spine, and chest were thought to show only an undisplaced fracture of the neck of the left scapula. The patient was admitted for observation and he rapidly recovered full consciousness without sequelae. His only remaining complaints were of pain on movement of the left shoulder and shortness of breath. While under observation, it was noted that he had a very wide arterial pulse pressure with a diastolic pressure of only 40 mm. Hg. No significance was attached to these findings or to his breathlessness and the patient was discharged from the hospital after 3 days. Three days later, the patient was referred back to the Royal Infirmary, Edinburgh, by his doctor and was readmitted as an emergency case. Following his initial discharge, his shortness of breath had increased until he became severely dyspneic and orthopneic. He also complained of central chest pain and had had one episode of hemoptysis. On examination, he was a heavily built man who was severely dyspneic while sitting up in bed. The laceration on his head was healing but there was a large bruised area on the anterior chest wall, centered on the manubriosternal joint. There was slight bilateral ankle edema. The jugular venous pressure was elevated 5 cm. above the clavicle. The pulse was regular with a rate of 114 beats per minute and markedly collapsing in character. There were vigorous carotid pulsations and the femoral pulses were both present and synchronous with the upper limb pulses. The blood pressure was 150/20 mm. Hg in both arms. Examination of the precordium revealed acute tenderness over the area of the manubriosternal joint. The apex beat was impalpable. Auscultation revealed a fourth heart sound with a Grade 2 systolic murmur maximal in the aortic area and radiating to the neck and a Grade 3 long diastolic murmur audible in all areas but maximal to the left of the sternum. An electrocardiogram confirmed normal sinus rhythm with no evidence of left ventricular hypertrophy or strain. The plain chest roentgenogram showed some enlargement of the
Volume 73 Number 2 February, 1977
Fig. 1. Plain chest roentgenograph taken 6 days following the injury. There is no widening of the superior mediastinum but the cardiac silhouette has increased in size and there is a collection of fluid in the left pleural cavity. The fractures of the left scapula and right first rib cannot be clearly identified on this film. cardiac silhouette but there was no significant widening of the superior mediastinum and the aortic knuckle was clearly visible. There was evidence of a collection of fluid in the left pleural cavity (Fig. 1). The fracture of the neck of the left scapula was confirmed and, in addition, an undisplaced fracture of the right first rib was identified for the first time. A fracture of the manubrium or sternum could not be identified radiologically. A provisional diagnosis of acute aortic dissection with aortic incompetence was made and he was submitted to emergency transfemoral aortography. This revealed a normal outline to the ascending aorta, arch, and descending aorta with no evidence of acute dissection. The major arch branches arose normally. There was gross aortic regurgitation and it was noticed that the right coronary sinus was a little dilated and distorted. At the upper margin of this sinus there was a tiny filling defect (Fig. 2). A diagnosis of traumatic rupture of the aorta and aortic valve was made and emergency operation recommended. At operation, the bruising of the skin over the sternum was related to a transverse undisplaced fracture of the lower manubrium. The pericardial cavity contained 200 ml. of heavily blood-stained fluid. The ascending aorta showed extensive external bruising with a subpericardial hematoma which extended into the epicardial fat around the right coronary artery. A diastolic thrill was easily palpable over the aortic root. Cardiopulmonary bypass was established and the aorta cross-clamped just proximal to the brachocephalic artery. The heart was cooled topically with ice-cold saline during the period of myocardial anoxia. The ascending aorta was opened longitudinally to reveal an anterior transverse tear around 250 degrees of the circumference at the level of the top of the commissures. The tear involved the intima and the media, leaving only the adventitial layers to support the aortic wall. There was no dissection distal to the tear but the lower intimal
Rupture of ascending aorta and aortic valve
209
Fig. 2. Aortogram of the ascending aorta showing a normal aortic arch and descending aorta. There is gross aortic regurgitation and the filling defect at the top of the aortic sinuses is marked by an arrow. flap had dissected down into the sinus over a distance of 8 mm., interfering with the support of the valve cusps. Apparently this small flap had produced the filling defect on the aortogram. The aortic valve was tricuspid and appeared to have been previously normal. However, the valve had been completely disrupted with a tear in each of the three leaflets. In the right and noncoronary leaflets, the tear extended from one commissure right across the center of the leaflet. In the left coronary leaflet a large linear tear was present centrally. The aortic valve was excised and replaced with a 23 mm. porcine heterograft prosthesis (Hancock Laboratories). The aorta was then transected at the level of the rupture and trimmed on both sides of the tear to remove completely the damaged area. Continuity was re-established with a 25 mm. woven Dacron tube graft. Cardiopulmonary bypass was easily discontinued and the operation concluded without incident. Examination of the removed valve cusps and aortic wall showed normal histology. Postoperatively the patient made an uneventful recovery and rapidly cleared all signs of congestive cardiac failure. He was gradually mobilized and given physiotherapy for his left shoulder. He was discharged on the twentieth postoperative day and 4 months later is asymptomatic and back to work. Discussion The clinical features, diagnosis, and treatment of traumatic rupture of the aortic isthmus 11 - 1 3 ' 2 4 , 2 5 or the origin of the major branches of the aortic arch 1 4 ' 2 2 have been well described. It has been estimated that only 10 to 15 per cent of casualties with an aortic tear survive
2 1 0 Charles et ah
the initial injury. Those that do survive often come to surgery within a few hours or days10, 21 but some remain undetected for a considerable period of time and develop a false aneurysm which may calcify. 3,15,23,25, 26 Much less frequently, blunt chest trauma is associated with rupture of a cardiac valve. There are very few reports of rupture of a normal aortic valve, although it has been reported to be associated with a fall from a height,29 a kick from a horse,1 a crushing injury of the chest,12' 14 or a road traffic accident.2' 9- 16~19 Traumatic rupture of a normal aorta and aortic valve with patient survival does not appear to have been previously reported. Cleveland and Cleveland4 described a patient with aortic regurgitation and congestive cardiac failure who at operation was found to have a hemopericardium and partial separation of the aortic root from the heart. Some time earlier he had been struck on the chest by a piece of flying metal. However, 2 years prior to this accident, the patient had sustained a dissection of the descending thoracic aorta which had been treated medically so that there may have been some inherent aortic abnormality. It is generally accepted that a tear at the aortic isthmus is due to rapid deacceleration of the thoracic cage with continuing forward movement of the heart and proximal aorta inside the chest, resulting in a tear of the aorta at its relatively fixed point near the aortic isthmus,10' 13' 17 but an alternative mechanism seems to have produced the unusual injuries seen in this patient. He had been driving without a seat belt when he was involved in a head-on collision. The presence of fractures of the left scapula, the right first rib, and the manubrium in a strongly built man suggests the application of very severe force to the thoracic cage. The transverse tear in the ascending aorta lay directly beneath the transverse fracture of the manubrium. We have hypothesized that the manubrium was fractured by coming into contact with the steering column of the vehicle and that, at the moment of impact, severe acute angular depression of the fractured manubrium occurred backward into the chest. The ascending aorta, still moving forward, then struck the sharp edge of the depressed manubrial fracture and this initiated the intimal tear. The total disruption of the aortic valve with tears in all three cusps suggests the application of a huge compressive force on the closed valve from above. Such an acute rise in ascending aortic pressure might have resulted from the temporary occlusion and compression of the proximal ascending aorta against the back of the manubrium and sternum in diastole. This case illustrates how major cardiovascular damage may be missed in an emergency situation in a pa-
The Journal of Thoracic and Cardiovascular Surgery
tient with more obvious external injuries. Intrathoracic cardiovascular trauma is commonly associated with extensive injury,6 especially fractures of the first rib. 5 ' 8 It was unfortunate that the fracture of the first rib was initially missed, since this might have increased the suspicion that intrathoracic soft-tissue damage might have occurred. In this case, there were additional clinical findings in the presence of an aortic diastolic murmur and a wide arterial pulse pressure, but the significance of these findings was not appreciated at first. Most importantly, the classic radiological sign of traumatic rupture of the aorta, i.e., a widened superior mediastinal shadow, was completely absent in this patient despite the severe vascular damage which had occurred. Since the aortic damage had occurred to the intrapericardial portion of the ascending aorta, the blood loss from the damaged vessel occurred into the pericardial cavity rather than the mediastinum and resulted in widening of the cardiac silhouette as the pericardium effusion developed over the first week after the accident. The importance of obtaining clear pictures of the ascending as well as the descending aorta at aortography in the investigation of patients with suspected aortic damage is also clearly illustrated in this patient. Although the patient had gross aortic regurgitation clearly demonstrated by aortography, the evidence for damage to the ascending aorta itself was much less obvious and would easily have been missed if clear pictures of the ascending aorta had not been obtained. Since one may conclude that traumatic tear of the ascending aorta can occur in the absence of aortic valve injury, it would appear to be important to perform ascending as well as descending aortograms in all patients with suspected aortic damage. The risk of complete rupture of the aorta following the initial partial tear is so high that emergency operation is generally considered mandatory once the diagnosis of traumatic rupture of the aorta has been confirmed by investigation. In this patient, the aortic valvular damage was so extensive that repair was impossible and the valve was therefore replaced with a heterograft prosthesis. In addition, the injured part of the aorta was removed and replaced routinely with a Dacron tube graft. REFERENCES 1 Barie, E.: Recherches cliniques et experimentales sur les ruptures valvulaires du coeur, Rev. Med. 1: 132, 1881. 2 Beall, A. C , Jr., and Shirkey, A. L.: Successful Surgical Correction of Traumatic Aortic Valve Regurgitation, J. A. M. A. 187: 507, 1964.
Volume 73 Number 2 February, 1977
3 Bjork, L., Hallen, A., and Westholm, C. J.: Traumatic Rupture of the Thoracic Aorta, Scand. J. Thorac. Cardiovasc. Surg. 5: 39, 1971. 4 Cleveland, J. C , and Cleveland, R. J.: Successful Repair of Aortic Root and Aortic Valve Injury Caused by Blunt Chest Trauma in a Patient With Prior Aortic Dissection, Chest 66: 447, 1974. 5 Galbraith, N. F., Urschel, H. C , Wood, R. E., et al.: Fracture of the First Rib Associated With Laceration of Subclavian Artery. Report of Case and Review of the Literature, J. THORAC. CARDIOVASC. SURG. 65: 649,
1973. 6 Geiran, O., and Solheim, K.: Cardiac and Aortic Injuries, Scand. J. Thorac. Cardiovasc. Surg. 8: 27, 1974. 7 Greendyke, R. M.: Traumatic Rupture of Aorta With Special Reference to Automobile Accidents, J. A. M. A. 195: 527, 1966. 8 Holmes, T. W., Jr., and Netterville, R. E.: Complications of First Rib Fracture, Including One Case Each of Tracheoesophageal Fistula and Aortic Arch Aneurysm, J. THORAC. SURG. 32: 74-91, 1956.
9 Irving, J. B.: Traumatic Aortic Incompetence Following Road Traffic Accident, Postgrad. Med. J. 50: 725, 1974. 10 Jahnke, E. J., Fisher, G. W., and Jones, R. C : Acute Traumatic Rupture of Thoracic Aorta: Report of 6 Consecutive Cases of Successful Early Repair, J. THORAC. CARDIOVASC. SURG. 48: 63-77, 1964.
11 Karp, R. B.: Traumatic Rupture of Thoracic Aorta, J. Med. Assoc. State Ala. 43: 553, 1974. 12 Kissane, R. W., Koons, R. A., and Clark, T. E.: Traumatic Rupture of Aortic Valve, Am. J. Med. 4: 606, 1948. 13 Lacquet, L. K., Kuijpers, P. J., Van Lent, D., Linssen, G. H., and Sutherland, I.: Traumatic Rupture of the Aortic Isthmus After Blunt Chest Trauma, J. Cardiovasc. Surg. (Torino) 15: 537, 1974. 14 Levine, R. J., Robertson, W. C , and Morrow, A. G.: Traumatic Aortic Regurgitation, Am. J. Cardiol. 10: 752, 1962. 15 McBurney, R. P., and Vaughan, R. H.: Rupture of the Thoracic Aorta Due to Nonpenetrating Trauma, Ann. Surg. 153: 670, 1961.
Rupture of ascending aorta and aortic valve
21 1
16 Parmely, L. F., Mattingly, T. W., Manion, W. C , and Jahnke, E. J.: Nonpenetrating Traumatic Injury of the Aorta, Circulation 17: 1086, 1958. 17 Pastershank, S. P., and Chow, K. C : Blunt Trauma to the Aorta and Its Major Branches, J. Can. Assoc. Radiol. 25: 202, 1974. 18 Payne, D. D., DeWeese, J. A., Mahoney, E. B., and Murphy, G. W.: Surgical Treatment of Traumatic Rupture of the Normal Aortic Valve, Ann. Thorac. Surg. 17: 233, 1974. 19 Proudfit, W. L., and McCormack, L. J.: Rupture of the Aortic Valve, Circulation 13: 750, 1956. 20 Reul, G. J., Rubio, P. A., and Beall, A. C : The surgical management of acute injury to the Thoracic Aorta, J. THORAC. CARDIOVASC. SURG. 67: 272, 1974.
21 Rittenhouse, E. A., Dillard, D. O., Wintercheid, L. C , and Merendino, A.: Traumatic Rupture of the Thoracic Aorta—Review of Literature and a Report of 5 Cases With Attention to Special Problems in Early Surgical Management, Ann. Surg. 170: 87, 1969. 22 Samaan, H. A.: Vascular Injuries of the Upper Thorax and the Root of the Neck, Br. J. Surg. 58: 881, 1971. 23 Slaney, G.: Vascular Deceleration Injuries, S. Afr. J. Surg. 12: 145, 1974. 24 Sharp, E. H., Cox, W. D., and Mullin, R.: Traumatic Rupture of Thoracic Aorta, Med. Trial. Tech. Q. 20: 159, 1973. 25 Spencer, F. C , Guerin, P. F., Blake, H. A., and Bahnson, H. T.: A Report of 15 Patients With Traumatic Rupture of Thoracic Aorta, J. THORAC. CARDIOVASC. SURG. 41: 1, 1961.
26 Steinberg, I.: Traumatic Aneurysm of the Thoracic Aorta. A Further Report, Am. J. Radiol. 91: 1295, 1964. 27 Strassman, G.: Traumatic Rupture of the Aorta, Am. Heart J. 33: 508, 1947. 28 Symbas, P. N., Tyras, D. H., Ware, R. E., and Diorio, D. A.: Traumatic Rupture of the Aorta, Ann. Surg. 178: 6, 1973. 29 Wilks, S.: Rupture of One of the Aortic Valves, Trans. Pathol. Soc. Lond. 21: 77, 1865.
Kelvin P. Charles, M . B . , Kenneth G. Davidson, F.R.C.S., Hugh Miller, M.B., and Philip K. Caves, F . R . C . S . , Edinburgh, Scotland
-L raumatic rupture of the thoracic aorta at the level of the ligamentum arteriosum is a well-recognized injury following severe blunt chest injury, particularly of the deacceleration type. 10, 15, 17, 24, 26, 28 Other injuries of the chest, head, abdomen, and l i m b s 6 , 7 " 1 0 ' 1 3 ' 1 5 , 2 0 , 2 5 ' 27 are commonly associated. Avulsion of the major branches of the arch of the thoracic aorta can also occur. 14, 22 By contrast, rupture of the ascending aorta with or without aortic valve damage following blunt chest trauma is rare and has been reported previously only in a patient with prior dissection of the descending thoracic aorta. 4 This paper reports successful surgical correction in a patient who suffered traumatic rupture of the ascending aorta and the aortic valve in a road traffic accident. Case history A 56-year-old railwayman was admitted to hospital as an emergency case in April, 1975, following a road traffic accident. The car which he had been driving had collided head-on with a tree while traveling at approximately 35 m.p.h. He was not wearing a seat belt. At the time of admission the patient was semiconscious and responding appropriately to painful stimuli. The only external From the University Department of Clinical Surgery and the Department of Cardiovascular Surgery, Royal Infirmary, Edinburgh, Scotland. Received for publication March 30, 1976. Accepted for publication Aug. 31, 1976. Address for reprints: Prof. Philip K. Caves, F.R.C.S., Department of Cardiothoracic Surgery, Royal Infirmary, Glasgow, Scotland.
208
evidence of injury was a laceration over his left eye. X-rays of his skull, cervical spine, and chest were thought to show only an undisplaced fracture of the neck of the left scapula. The patient was admitted for observation and he rapidly recovered full consciousness without sequelae. His only remaining complaints were of pain on movement of the left shoulder and shortness of breath. While under observation, it was noted that he had a very wide arterial pulse pressure with a diastolic pressure of only 40 mm. Hg. No significance was attached to these findings or to his breathlessness and the patient was discharged from the hospital after 3 days. Three days later, the patient was referred back to the Royal Infirmary, Edinburgh, by his doctor and was readmitted as an emergency case. Following his initial discharge, his shortness of breath had increased until he became severely dyspneic and orthopneic. He also complained of central chest pain and had had one episode of hemoptysis. On examination, he was a heavily built man who was severely dyspneic while sitting up in bed. The laceration on his head was healing but there was a large bruised area on the anterior chest wall, centered on the manubriosternal joint. There was slight bilateral ankle edema. The jugular venous pressure was elevated 5 cm. above the clavicle. The pulse was regular with a rate of 114 beats per minute and markedly collapsing in character. There were vigorous carotid pulsations and the femoral pulses were both present and synchronous with the upper limb pulses. The blood pressure was 150/20 mm. Hg in both arms. Examination of the precordium revealed acute tenderness over the area of the manubriosternal joint. The apex beat was impalpable. Auscultation revealed a fourth heart sound with a Grade 2 systolic murmur maximal in the aortic area and radiating to the neck and a Grade 3 long diastolic murmur audible in all areas but maximal to the left of the sternum. An electrocardiogram confirmed normal sinus rhythm with no evidence of left ventricular hypertrophy or strain. The plain chest roentgenogram showed some enlargement of the
Volume 73 Number 2 February, 1977
Fig. 1. Plain chest roentgenograph taken 6 days following the injury. There is no widening of the superior mediastinum but the cardiac silhouette has increased in size and there is a collection of fluid in the left pleural cavity. The fractures of the left scapula and right first rib cannot be clearly identified on this film. cardiac silhouette but there was no significant widening of the superior mediastinum and the aortic knuckle was clearly visible. There was evidence of a collection of fluid in the left pleural cavity (Fig. 1). The fracture of the neck of the left scapula was confirmed and, in addition, an undisplaced fracture of the right first rib was identified for the first time. A fracture of the manubrium or sternum could not be identified radiologically. A provisional diagnosis of acute aortic dissection with aortic incompetence was made and he was submitted to emergency transfemoral aortography. This revealed a normal outline to the ascending aorta, arch, and descending aorta with no evidence of acute dissection. The major arch branches arose normally. There was gross aortic regurgitation and it was noticed that the right coronary sinus was a little dilated and distorted. At the upper margin of this sinus there was a tiny filling defect (Fig. 2). A diagnosis of traumatic rupture of the aorta and aortic valve was made and emergency operation recommended. At operation, the bruising of the skin over the sternum was related to a transverse undisplaced fracture of the lower manubrium. The pericardial cavity contained 200 ml. of heavily blood-stained fluid. The ascending aorta showed extensive external bruising with a subpericardial hematoma which extended into the epicardial fat around the right coronary artery. A diastolic thrill was easily palpable over the aortic root. Cardiopulmonary bypass was established and the aorta cross-clamped just proximal to the brachocephalic artery. The heart was cooled topically with ice-cold saline during the period of myocardial anoxia. The ascending aorta was opened longitudinally to reveal an anterior transverse tear around 250 degrees of the circumference at the level of the top of the commissures. The tear involved the intima and the media, leaving only the adventitial layers to support the aortic wall. There was no dissection distal to the tear but the lower intimal
Rupture of ascending aorta and aortic valve
209
Fig. 2. Aortogram of the ascending aorta showing a normal aortic arch and descending aorta. There is gross aortic regurgitation and the filling defect at the top of the aortic sinuses is marked by an arrow. flap had dissected down into the sinus over a distance of 8 mm., interfering with the support of the valve cusps. Apparently this small flap had produced the filling defect on the aortogram. The aortic valve was tricuspid and appeared to have been previously normal. However, the valve had been completely disrupted with a tear in each of the three leaflets. In the right and noncoronary leaflets, the tear extended from one commissure right across the center of the leaflet. In the left coronary leaflet a large linear tear was present centrally. The aortic valve was excised and replaced with a 23 mm. porcine heterograft prosthesis (Hancock Laboratories). The aorta was then transected at the level of the rupture and trimmed on both sides of the tear to remove completely the damaged area. Continuity was re-established with a 25 mm. woven Dacron tube graft. Cardiopulmonary bypass was easily discontinued and the operation concluded without incident. Examination of the removed valve cusps and aortic wall showed normal histology. Postoperatively the patient made an uneventful recovery and rapidly cleared all signs of congestive cardiac failure. He was gradually mobilized and given physiotherapy for his left shoulder. He was discharged on the twentieth postoperative day and 4 months later is asymptomatic and back to work. Discussion The clinical features, diagnosis, and treatment of traumatic rupture of the aortic isthmus 11 - 1 3 ' 2 4 , 2 5 or the origin of the major branches of the aortic arch 1 4 ' 2 2 have been well described. It has been estimated that only 10 to 15 per cent of casualties with an aortic tear survive
2 1 0 Charles et ah
the initial injury. Those that do survive often come to surgery within a few hours or days10, 21 but some remain undetected for a considerable period of time and develop a false aneurysm which may calcify. 3,15,23,25, 26 Much less frequently, blunt chest trauma is associated with rupture of a cardiac valve. There are very few reports of rupture of a normal aortic valve, although it has been reported to be associated with a fall from a height,29 a kick from a horse,1 a crushing injury of the chest,12' 14 or a road traffic accident.2' 9- 16~19 Traumatic rupture of a normal aorta and aortic valve with patient survival does not appear to have been previously reported. Cleveland and Cleveland4 described a patient with aortic regurgitation and congestive cardiac failure who at operation was found to have a hemopericardium and partial separation of the aortic root from the heart. Some time earlier he had been struck on the chest by a piece of flying metal. However, 2 years prior to this accident, the patient had sustained a dissection of the descending thoracic aorta which had been treated medically so that there may have been some inherent aortic abnormality. It is generally accepted that a tear at the aortic isthmus is due to rapid deacceleration of the thoracic cage with continuing forward movement of the heart and proximal aorta inside the chest, resulting in a tear of the aorta at its relatively fixed point near the aortic isthmus,10' 13' 17 but an alternative mechanism seems to have produced the unusual injuries seen in this patient. He had been driving without a seat belt when he was involved in a head-on collision. The presence of fractures of the left scapula, the right first rib, and the manubrium in a strongly built man suggests the application of very severe force to the thoracic cage. The transverse tear in the ascending aorta lay directly beneath the transverse fracture of the manubrium. We have hypothesized that the manubrium was fractured by coming into contact with the steering column of the vehicle and that, at the moment of impact, severe acute angular depression of the fractured manubrium occurred backward into the chest. The ascending aorta, still moving forward, then struck the sharp edge of the depressed manubrial fracture and this initiated the intimal tear. The total disruption of the aortic valve with tears in all three cusps suggests the application of a huge compressive force on the closed valve from above. Such an acute rise in ascending aortic pressure might have resulted from the temporary occlusion and compression of the proximal ascending aorta against the back of the manubrium and sternum in diastole. This case illustrates how major cardiovascular damage may be missed in an emergency situation in a pa-
The Journal of Thoracic and Cardiovascular Surgery
tient with more obvious external injuries. Intrathoracic cardiovascular trauma is commonly associated with extensive injury,6 especially fractures of the first rib. 5 ' 8 It was unfortunate that the fracture of the first rib was initially missed, since this might have increased the suspicion that intrathoracic soft-tissue damage might have occurred. In this case, there were additional clinical findings in the presence of an aortic diastolic murmur and a wide arterial pulse pressure, but the significance of these findings was not appreciated at first. Most importantly, the classic radiological sign of traumatic rupture of the aorta, i.e., a widened superior mediastinal shadow, was completely absent in this patient despite the severe vascular damage which had occurred. Since the aortic damage had occurred to the intrapericardial portion of the ascending aorta, the blood loss from the damaged vessel occurred into the pericardial cavity rather than the mediastinum and resulted in widening of the cardiac silhouette as the pericardium effusion developed over the first week after the accident. The importance of obtaining clear pictures of the ascending as well as the descending aorta at aortography in the investigation of patients with suspected aortic damage is also clearly illustrated in this patient. Although the patient had gross aortic regurgitation clearly demonstrated by aortography, the evidence for damage to the ascending aorta itself was much less obvious and would easily have been missed if clear pictures of the ascending aorta had not been obtained. Since one may conclude that traumatic tear of the ascending aorta can occur in the absence of aortic valve injury, it would appear to be important to perform ascending as well as descending aortograms in all patients with suspected aortic damage. The risk of complete rupture of the aorta following the initial partial tear is so high that emergency operation is generally considered mandatory once the diagnosis of traumatic rupture of the aorta has been confirmed by investigation. In this patient, the aortic valvular damage was so extensive that repair was impossible and the valve was therefore replaced with a heterograft prosthesis. In addition, the injured part of the aorta was removed and replaced routinely with a Dacron tube graft. REFERENCES 1 Barie, E.: Recherches cliniques et experimentales sur les ruptures valvulaires du coeur, Rev. Med. 1: 132, 1881. 2 Beall, A. C , Jr., and Shirkey, A. L.: Successful Surgical Correction of Traumatic Aortic Valve Regurgitation, J. A. M. A. 187: 507, 1964.
Volume 73 Number 2 February, 1977
3 Bjork, L., Hallen, A., and Westholm, C. J.: Traumatic Rupture of the Thoracic Aorta, Scand. J. Thorac. Cardiovasc. Surg. 5: 39, 1971. 4 Cleveland, J. C , and Cleveland, R. J.: Successful Repair of Aortic Root and Aortic Valve Injury Caused by Blunt Chest Trauma in a Patient With Prior Aortic Dissection, Chest 66: 447, 1974. 5 Galbraith, N. F., Urschel, H. C , Wood, R. E., et al.: Fracture of the First Rib Associated With Laceration of Subclavian Artery. Report of Case and Review of the Literature, J. THORAC. CARDIOVASC. SURG. 65: 649,
1973. 6 Geiran, O., and Solheim, K.: Cardiac and Aortic Injuries, Scand. J. Thorac. Cardiovasc. Surg. 8: 27, 1974. 7 Greendyke, R. M.: Traumatic Rupture of Aorta With Special Reference to Automobile Accidents, J. A. M. A. 195: 527, 1966. 8 Holmes, T. W., Jr., and Netterville, R. E.: Complications of First Rib Fracture, Including One Case Each of Tracheoesophageal Fistula and Aortic Arch Aneurysm, J. THORAC. SURG. 32: 74-91, 1956.
9 Irving, J. B.: Traumatic Aortic Incompetence Following Road Traffic Accident, Postgrad. Med. J. 50: 725, 1974. 10 Jahnke, E. J., Fisher, G. W., and Jones, R. C : Acute Traumatic Rupture of Thoracic Aorta: Report of 6 Consecutive Cases of Successful Early Repair, J. THORAC. CARDIOVASC. SURG. 48: 63-77, 1964.
11 Karp, R. B.: Traumatic Rupture of Thoracic Aorta, J. Med. Assoc. State Ala. 43: 553, 1974. 12 Kissane, R. W., Koons, R. A., and Clark, T. E.: Traumatic Rupture of Aortic Valve, Am. J. Med. 4: 606, 1948. 13 Lacquet, L. K., Kuijpers, P. J., Van Lent, D., Linssen, G. H., and Sutherland, I.: Traumatic Rupture of the Aortic Isthmus After Blunt Chest Trauma, J. Cardiovasc. Surg. (Torino) 15: 537, 1974. 14 Levine, R. J., Robertson, W. C , and Morrow, A. G.: Traumatic Aortic Regurgitation, Am. J. Cardiol. 10: 752, 1962. 15 McBurney, R. P., and Vaughan, R. H.: Rupture of the Thoracic Aorta Due to Nonpenetrating Trauma, Ann. Surg. 153: 670, 1961.
Rupture of ascending aorta and aortic valve
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16 Parmely, L. F., Mattingly, T. W., Manion, W. C , and Jahnke, E. J.: Nonpenetrating Traumatic Injury of the Aorta, Circulation 17: 1086, 1958. 17 Pastershank, S. P., and Chow, K. C : Blunt Trauma to the Aorta and Its Major Branches, J. Can. Assoc. Radiol. 25: 202, 1974. 18 Payne, D. D., DeWeese, J. A., Mahoney, E. B., and Murphy, G. W.: Surgical Treatment of Traumatic Rupture of the Normal Aortic Valve, Ann. Thorac. Surg. 17: 233, 1974. 19 Proudfit, W. L., and McCormack, L. J.: Rupture of the Aortic Valve, Circulation 13: 750, 1956. 20 Reul, G. J., Rubio, P. A., and Beall, A. C : The surgical management of acute injury to the Thoracic Aorta, J. THORAC. CARDIOVASC. SURG. 67: 272, 1974.
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