Ann Thorac Surg 2006;81:2294-2296
© 2006 The Society of Thoracic Surgeons
Case report
Stanford Type A Acute Aortic Dissection Caused by Blunt Trauma in a Patient with Situs Inversus
Katsuaki Magishi, MD
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,
Yuichi Izumi, MD,
Noriyuki Ishikawa, MD,
Fumiaki Kimura, MD
Department of Thoracic and Cardiovascular Surgery, Nayoro City General Hospital, Hokkaido, Japan
Accepted for publication August 29, 2005.
* Address correspondence to Dr Magishi, Department of Thoracic and Cardiovascular Surgery, Nayoro City General Hospital, Nishi 7-Minami 8, Nayoro, Hokkaido, 096-8511 Japan (Email: k-magishi{at}k5.dion.ne.jp).
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Abstract
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We report a case of Stanford type A acute aortic dissection caused by blunt trauma in a patient with situs inversus. A 57-year-old man was involved in an explosion accident. It was indicated that he had suffered Stanford type A acute aortic dissection, cardiac tamponade, and situs inversus by contrast enhanced computed tomography and echocardiography. With the introduction of anesthesia, he went into shock. An extracorporeal circuit was immediately introduced with heart massage. The ascending aorta was replaced with a prosthesis using cardiopulmonary bypass. The branches of the aortic arch were mirror-image reversed. The patient's general condition improved, and he was discharged from our department 3 weeks after the operation.
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Introduction
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Dextrocardia refers to a condition in which the cardiac apex is in the right thorax with a reversal of the axis of cardiac inclination. Situs inversus totalis is a rare congenital cardiac malformation characterized by a perfect mirror image of the normal anatomy of the visceral organs. The present case involved blunt injury of the ascending aorta in situs inversus totalis without malformation, which was caused by a gas explosion.
A 57-year-old man was involved in an explosion accident during a fire extinguisher exchange in a gas station. He suffered from the gas explosion (not from the fire extinguisher) on his front chest, and he was blown away several meters. He was quickly transported to the hospital. It was indicated that he had suffered Stanford type A acute aortic dissection, cardiac tamponade, and situs inversus (Fig 1) by contrast computed tomography and echocardiography. He did not have any past illness, and the echocardiogram did not reveal aortic valve regurgitation or a concurrent cardiac anomaly. No injury other than the chest trauma was detected by the computed tomographic scan. We did not detect the fracture of the rib and the sternum. His blood pressure was unstable during the state of shock. Immediately he was transferred from the first hospital to our hospital with pericardium drainage, and he was moved quickly to the operating room. During the introduction of anesthesia, he had bradycardia develop, and his systolic blood pressure dropped to 30 to 40 mm Hg. Extracorporeal bypass was introduced using the left femoral artery and vein while heart massage was sustained. Because of the situs inversus, the operator stood at the left side of the patient. During incision we observed extensive subcutaneous hemorrhage but no fracture of the sternum. After median sternotomy and an opening of the pericardium, the ascending aorta ruptured free and bled about 5 cm below the left brachiocephalic artery (Fig 2). Three branch arteries of the arch were completely reversed to form a mirror image of their normal situation; the first branch was the left brachiocephalic artery, the second was the right carotid artery, and the third was the right subclavian artery. The anatomical right atrium was on the left side, and the great vein was also on the left side. Venous cannula was changed from the femoral vein to the left (ie, or anatomical right) atrium during the assistant pressed on the aortic bleeding point with his finger. A left ventricular venting tube was inserted through the left superior pulmonary vein. Because of the normal finding, the aorta was clamped on the proximal side of the brachiocephalic artery and cardiac arrest using blood cold cardioplegia was induced. The rectum temperature was at 29.2°C. The intimal tear was located distal of the sinotubular junction, and the dissection was limited to the ascending aorta. The ascending aorta was replaced by a 24-mm woven Dacron prosthesis (Polyester Gelatin, Gelweave, Vascutek, UK). Removing the patient from cardiopulmonary bypass was not difficult. In his postoperative course, the patient was disoriented for 2 weeks. A computed tomographic brain scan showed cerebral hemorrhage in the right occipital lobe of the cerebrum, which was not seen before the operation. Postoperative computed tomographic scanning (maximum intensity projection image) showed a mirror-imaged aortic arch (Fig 3). The patient improved until he was in good general condition, and he was discharged from our hospital 3 weeks after the operation.
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Fig 1. Chest computed tomographic image showing a dissection of the ascending aorta (Asc.Ao). Pericardiac hematoma is shown (arrow).
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Fig 2. Operative findings: the opening of the pericardium and bleeding from the ascending aorta (Asc.Ao; arrow) are shown. Dissection was limited to the ascending aorta. It can be seen that the venous cannula was inserted in the left atrium.
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Fig 3. Postoperative computed tomographic imaging (maximum intensity projection image) showed the branches of the aortic arch to be in a formation that was a mirror image of the normal formation. It can be seen that the spleen is on the right side (arrow).
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Comment
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Traumatic rupture of the thoracic aorta remains a surgical challenge. Its mortality rate is high, and its morbidity is tragic. About 70% to 90% of blunt aortic injuries are caused by traffic accidents [1, 2]. This injury may involve polytraumatism, so it is difficult to determine a treatment strategy. Acute traumatic aortic injury occurs most commonly in the upper descending thoracic aorta at or near the aortic isthmus. However, damage to the ascending aorta is extremely rare. Carter and colleagues [3] reported that the ascending aortic injury was 1 of 122 blunt thoracic aortic injuries. Cammack and colleagues [4] showed that vertical forces of deceleration tend to lead to the rupture of the ascending aorta, whereas horizontal forces lead to the rupture of the descending aorta. Blunt ascending aortic injury usually occurs near the origin of the brachiocephalic artery; less commonly, it occurs at the proximal portion of the ascending aorta [3]. It may be caused by the increasing of the pressure in the ascending aorta due to compression by horizontal forces. In the present case, the explosion gas, not the fire extinguisher, struck the front of the chest of the subject with a force that was horizontal to the chest, but he did not have a fracture of the sternum. The strong vertical forces to the chest wall may have compressed the ascending aorta directly and instantly so that the dissection and rupture of the ascending aorta may have occurred. In this case, the middle portion of the ascending aorta was dissected and ruptured and localized the ascending aortic dissection, the proximal part of the aortic arch was clamped and replaced with a prosthesis.
Situs inversus occurs in 1 of 6,000 to 8,000 births. In most cases, some cardiac or internal organ anomaly is present. In this case, however, there were no abnormalities in the visceral organ, including that of the heart.
The surgical technique is not unusual, but surgeons may be confused due to the mirror image situation. There are no previous reports on blunt ascending aortic injury complicated by situs inversus. This case was extremely rare.
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References
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- Tatou E, Steinmetz E, Jazayeri S, et al. Surgical outcome of traumatic rupture of the thoracic aorta Ann Thorac Surg 2000;69:70-73.[Abstract/Free Full Text]
- Johromi SA, Kazemi K, Safar AH, et al. Traumatic rupture of the thoracic aortacohort study and systematic review. J Vasc Surg 2001;34:1029-1034.[Medline]
- Carter Y, Meissner M, Bulger E, et al. Anatomical considerations in the surgical management of blunt thoracic aortic injury J Vasc Surg 2001;34:628-633.[Medline]
- Cammack K, Rapport RL, Paul J. Deceleration injuries of the thoracic aorta Arch Surg 1959;79:244-251.[Abstract/Free Full Text]
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Abstract
Introduction
