Acute aortic dissection and a ruptured aortic aneurysm are both catastrophic events that usually present suddenly. Although these conditions are relatively uncommon compared to other diseases treated by the orthopedists as a primary practitioner, they are of primary importance. The purpose of this study was to investigate the key points that differentiate these conditions from spinal disease.
A review of 50 patients with aortic dissection (n=40) or a ruptured aortic aneurysm (n=10) was performed to determine the manifestations (eg, back pain and paraplegia). We also evaluated the predisposing factor and blood pressure on admission and reviewed clinical imaging (radiographs, computed tomography [CT]) retrospectively.
Sudden severe isolated back pain was observed in 18 (45.0%) of 40 patients, and 31 (77.5%) of 40 patients had at least some back pain in aortic dissection, while 1 patient had sudden paraplegia with a ruptured aortic aneurysm. Hypertension was the most predisposing factor and was present in 29 (58.0%) of 50 patients. On admission, hypertension was present in 26 (56.5%) of 46 patients, and hypotension was present in 14 (30.4%) of 46 patients. In all cases, the correct diagnosis was made based on CT.
For a patient with an abrupt onset of severe back pain, acute aortic dissection and a ruptured aortic aneurysm should be considered in the differential diagnosis from spinal disease. The most reliable tool for imaging diagnosis was CT.
Aortic dissection and a ruptured aortic aneurysm are among the most common fatal conditions that cause sudden death. Therefore, appropriate diagnosis and prompt treatment are required for this medical emergency. Misdiagnosis or improper treatment may result in medical malpractice problems. In fact, malpractice suits have been initiated in some cases. Nevertheless, prompt diagnosis may be difficult due to many different symptoms, such as severe chest pain, back pain, abdominal pain, cold sweat, dyspnea, disturbance of consciousness, vomiting, incontinence, melena, etc. The frequency of back pain at the time of initial complaint is high,1-4 and the sudden onset of paraplegia without pain is sometimes reported.5-11 Thus, we assume that aortic dissection or a ruptured aortic aneurysm is of paramount importance for the orthopedist as a primary practitioner, although these diseases are seldom encountered.
This study evaluated the clinical manifestations including back pain and paraplegia in the acute phase, and retrospective analysis of the clinical data revealed the key points that differentiated these conditions from spinal disease.
Materials and Methods
We reviewed the medical records of 50 patients (36 men and 14 women, mean age 69 years) who presented with substantiated aortic dissection or a ruptured aortic aneurysm to Kouseiren Takaoka Hospital between January 1999 and December 2002.
Classification of aortic dissection is based on anatomical location. The Stanford classification consists of: type A, involving the ascending aorta regardless of the entry site location; and type B, involving the aorta distal to the origin of the left subclavian artery.12 Aortic dissections were present in 40 patients, 20 patients with Stanford Type A and 20 patients with Stanford Type B. Ruptured aortic aneurysms were present in 10 patients, in 4 with thoracic aortic aneurysm, and in 6 with abdominal aortic aneurysm.
We investigated clinical manifestations at the time of initial assessment in patients, predisposing factor, and blood pressure at the time of arrival from the medical records. We also evaluated chest radiographs for patients with aortic dissection and thoracic aortic aneurysm, abdominal radiographs for patients with abdominal aortic aneurysm, and computed tomography (CT) scans for all patients retrospectively.
The manifestations at the time of initial assessment in patients of aortic dissection or a ruptured aortic aneurysm in our series of patients are summarized in Table 1. The most frequent complaint was that of sudden severe isolated low back or back pain, which was present in 10 of 20 patients (50%) with type A aortic dissection and in 8 of 20 patients (40%) with type B aortic dissection. Concomitant chest or abdominal pain, back pain was present in 31 of 40 patients with aortic dissection overall (77.5%). The feature of pain was abruptness and not related to movement.
Upon presentation, 5 of 10 patients with ruptured aortic aneurysm were in shock. Back pain was present in 3 patients, and another patient reported sudden paraplegia. All 10 patients with ruptured aortic aneurysm developed hypovolemic shock within several hours. However, 1 of 40 patients with aortic dissection developed hypovolemic shock within several hours.
We found descriptions of predisposing factors from medical records of 50 patients. In the current series, the most common condition that predisposed them to aortic dissection or a ruptured aortic aneurysm was hypertension, which was present in 29 patients (58%) (Figure 1). Eight patients had diabetes mellitus. Five patients had brain infarction. Bronchial asthma, hyperlipidemia, or abdominal aortic aneurysms were present in 3 patients each, respectively, and thoracic aortic aneurysm were present in 2 patients.
Upon presentation, 6 patients (16.7%) showed low systolic pressure and 24 patients (66.7%) showed high systolic pressure in aortic dissection. Six patients (16.7%) showed normal pressure. In 4 patients, there was no data regarding blood pressure. Abnormal blood pressure on admission was present in 30 of 36 patients (83.3%) (Table 2). In ruptured aortic aneurysm, 8 patients showed low systolic pressure (≤100 mm Hg), 2 patients showed high systolic pressure (≥140 mm Hg). However, all 10 patients developed hypovolemic shock within several hours.
Chest radiographs were performed in all 40 patients with aortic dissection. The mediastinal silhouette was widened in 13 of 20 patients (65%) with type A aortic dissection, and in 12 of 20 patients (60%) with type B aortic dissection. However, the initial radiograph for 7 patients with type A patients (35%) and 8 patients with type B patients (40%) revealed no specific abnormalities of the aorta, mediastinum, or pleural space. In contrast, the diagnosis of aortic dissection had been established by CT scan for all patients. Chest radiographs demonstrated abnormal findings for all 4 patients with ruptured thoracic aortic aneurysm patients. The mediastinal silhouette was widened in all patients, and there was a strong suspicion of ruptured aortic aneurysm in 2 because of marked dilation of the mediastinal silhouette. The abdominal radiograph showed the disappearance of psoas muscle shadow in 5 of 6 patients with ruptured abdominal aortic aneurysm. In one remaining patient, it was difficult to determine. The diagnosis of abdominal aortic aneurysm was possible for 4 of 6 patients due to the extent of aortic wall calcification. The diagnosis of a ruptured aortic aneurysm had been established by a CT scan for 9 of 10 patients who remained in alive. One patient was diagnosed at autopsy using a CT scan.
Five of 20 patients (25%) with type A aortic dissection and 2 of 20 patients (10%) with type B aortic dissection died at intensive care unit within 5 days. One patient with type A aortic dissection died 3 weeks after onset of symptoms. Three patients who were in shock at presentation were included in these 8 patients who died within 3 weeks. The others were alive >1 month after onset of symptoms. All of the patients with a ruptured thoracic aortic aneurysm and 3 of the 6 patients with ruptured abdominal aortic aneurysm died within 24 hours. One patient died 3 days after onset of symptoms. Only 2 patients were alive >1 month after onset of symptoms.
A 65-year-old man presented with sudden severe back pain. He had a past history of hypertension and brain infarction. On presentation to the emergency department, he remained awake and alert. He was not in shock, but he reported severe back pain irrespective of motion and rest. His blood pressure on admission was 174/78 mm Hg, and his pulse was 40 beats/min.
Chest radiograph on admission revealed dilation of the mediastinal silhouette (Figure 2A). Plain CT scan showed calcifications within the intimomedial flap and pseudolumen (Figure 2B). An enhanced CT scan revealed an intramural thrombus in the false lumen (Figure 2C). The patient was diagnosed with acute aortic dissection of Stanford type B. He was treated conservatively by controlling his blood pressure, and he gradually recovered.
An 84-year-old woman presented after she was unable to move her lower extremities. Her only past history was significant for diabetes mellitus.
She reported having no back, chest, abdominal, arm, or leg pain. She had neither syncope nor dyspnea. However, manual muscle testing revealed the strength of the muscle groups in her lower extremities to be 0/5. A sensory test showed a marked decrease in pain and temperature sensation, but not complete anesthesia.
Blood pressure on admission was 98/54 mm Hg, and her pulse was 66 beats/min, but her systolic blood pressure was unstable, varying considerably from 71 mm Hg to 174 mm Hg over just 1 hour. Our initial impression was that the lumbar radiograph revealed no specific abnormalities that led to the diagnosis. However, when the lumbar radiograph was evaluated retrospectively, disappearance of the right psoas shadow was revealed (Figure 3A).
Magnetic resonance imaging revealed a normal thoracolumbar spinal cord and dural sac. However, in front of the vertebral body at the L2-5 level, a cyst-like lesion with varying density was observed. Magnetic resonance imaging revealed an abdominal aortic aneurysm (Figure 3B). Computed tomography scan showed a ruptured aortic aneurysm and a hematoma along the right iliopsoas (Figure 3C). She was treated conservatively by controlling her blood pressure; she was not a candidate for surgery due to her general medical condition. She died of a re-ruptured aortic aneurysm 12 hours after admission.
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Figure 3: Case 2. Abdominal radiograph revealed that the right psoas line had disappeared (A). In front of the vertebral body at the L2-5 level, there was cyst-like lesion with varying brightness. MRI revealed the presence of an abdominal aortic aneurysm (B). CT scan showed a ruptured aortic aneurysm and a hematoma along the right iliopsoas (arrow) (C).
An increasing number of patients present with acute aortic dissection and a ruptured aortic aneurysm due to aging population and an increase in environment factors causing arteriosclerosis in Japan. Diagnostic delays following the onset of symptoms can result in death and/or malpractice claims. Therefore, appropriate diagnosis and prompt treatment is important for those treating this type of medical emergency.
The correct diagnosis rate based on initial clinical impressions has not been high.3,13,14 Murai15 conducted a statistical analysis of aortic dissection autopsies performed from 1949 to 1987 at the Tokyo-to Medical Examiner office. He reported that 63 of 105 (61.4%) patients with acute aortic dissection had been discharged home with no anticipation of sudden death. Only 1 of the patients was diagnosed correctly at the initial examination. However, this study was conducted of autopsied cases of unexpected death. Other studies reported that the correct diagnosis had not been made before postmortem examination for 14% to 28% of patients.3,14
Various symptoms at presentation is the primary reason that this diagnosis is difficult. In particular, this condition constitutes a potential pitfall for orthopedists as a primary practitioner, because back pain is a symptom reported with high frequency.
According to a published analysis, back pain was reported by 38.7% to 53.2% of patients with aortic dissection.1,2 In our current series, back pain was present in 77.5% of patients with aortic dissection. Isolated back pain affected 45% of patients.
The most specific characteristic of the pain is the abrupt onset, and also sharp nature without relation to movement. In addition, careful physical examination should be performed to identify the combination of chest or abdominal pain. Darling4 reported that midline back pain, usually constant and severe, was present in >90% of the patients who had a ruptured abdominal aortic aneurysm. In this study, back pain was present in 3 of 10 patients with ruptured aortic aneurysm. However, all patients were in hypovolemic shock within several hours. Thus, it is important not to overlook the signs of shock to differentiate ruptured aortic aneurysm from spinal disease.
The acute onset of paraplegia can be a dramatic manifestation of acute aortic diseases. From a review of the literature of 1805 patients with aortic dissection, Zull and Cydulka5 reported that 4.2% presented with acute paraplegia or paraparesis. Most of these patients experienced severe pain prior to the development of paraplegia. However, the acute onset paraplegia without pain has been reported occasionally.5-11 Our case of ruptured aortic aneurysm associated with sudden paraplegia was rare. Intercostal or lumbar artery occlusion can cause ischemia to the spinal cord, resulting in acute paraplegia. The lower half of the spinal cord is supplied by direct branches from the aorta. When these vessels are sheared off by aortic dissection or ruptured aortic aneurysm, paraplegia or paraparesis may occur due to spinal cord ischemia.5
A history of hypertension was the most important risk factor, with a high frequency.1,3,13 In our study, hypertension was present in 29 patients (58%).
In aortic dissection patients, 83.3% of cases showed abnormal blood pressure at the time of presentation, of which 80% showed high systolic blood pressure. Meszaros et al13 reported 67% of aortic dissection showed abnormal blood pressure. This underscores the notion that even if the symptom is only back pain, attention is required to the character of pain and the patients blood pressure.
Abnormal signs were detected by radiograph in patients with ruptured aortic aneurysm, but in aortic dissection, 42.5% of patients showed normal findings retrospectively. However, CT scan detected aortic dissection for all patients indicating its usefulness as a tool for diagnosis. Despite recent reports of high sensitivity and specificity of MRI, it was rarely used as a first diagnostic imaging method.16 Magnetic resonance imaging requires a long examination time, and the restricted monitoring of vital signs, which is especially problematic in hemodynamically unstable patients.
Acute aortic dissection or ruptured aortic aneurysm could be the cause of symptoms of patients with back pain. The key points that differentiated these entities from a spinal disorder were as follows1,3,13:
- severe back pain independent of the patients body position,
- complicated symptom of chest or abdominal pain,
- aortic calcification and abnormal findings of the psoas line at abdominal radiograph,
- past history of hypertension, and
- abnormal blood pressure on admission.
Although it is relatively uncommon for the orthopedist to see aortic dissection or a ruptured aortic aneurysm, these diseases are of primary importance from the aspect of critical care medicine. In our series, the initial chest radiograph for 15 patients (30%) revealed no specific abnormalities. Because normal radiographic findings do not exclude the possibility of these aortic diseases, we recommend making a diagnosis following a CT scan for patients who have a history of hypertension, abnormal blood pressure on admission, or severe back pain without relation to movement.
- Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA. 2000; 283(7):897-903.
- Bickerstaff LK, Pairolero PC, Hollier LH, et al. Thoracic aortic aneurysms: a population-based study. Surgery. 1982; 92(6):1103-1108.
- Spittell PC, Spittell JA Jr, Joyce JW, et al. Clinical features and differential diagnosis of aortic dissection: experience with 236 cases (1980 through 1990). Mayo clin Proc. 1993; 68(7):642-651.
- Darling RC. Ruptured arteriosclerotic abdominal aortic aneurysms: a pathologic and clinical study. Am J Surg. 1970; 119(4):397-401.
- Zull DN, Cydulka R. Acute paraplegia: a presenting manifestation of aortic dissection. Am J Med. 1988; 84(4):765-770.
- Donovan EM, Seidel GK, Cohen A. Painless aortic dissection presenting as high paraplegia: a case report. Arch Phys Med Rehabil. 2000; 81(10):1436-1438.
- Gerber O, Heyer EJ, Vieux U. Painless dissections of the aorta presenting as acute neurologic syndromes. Stroke. 1986; 17(4):644-647.
- Inamasu J, Hori S, Yokoyama M, Funabiki T, Aoki K, Aikawa N. Paraplegia caused by painless acute aortic dissection. Spinal Cord. 2000; 38(11):702-704.
- Joo JB, Cummings AJ. Acute thoracoabdominal aortic dissection presenting as painless, transient paralysis of the lower extremities: a case report. J Emerg Med. 2000; 19(4):333-337.
- Rosen SA. Painless aortic dissection presenting as spinal cord ischemia. Ann Emerg Med. 1988; 17(8):840-842.
- Kamano S, Yonezawa I, Arai Y, Iizuka Y, Kurosawa H. Acute abdominal aortic aneurysm rupture presenting as transient paralysis of the lower legs: a case report. J Emerg Med. 2005; 29(1):53-55.
- Daily PO, Trueblood HW, Stinson EB, Wuerflein RD, Shumway NE. Management of acute aortic dissections. Ann Thorac Surg. 1970; 10(3):237-246.
- Meszaros I, Morocz J, Szlavi J, Schmidt J, Tornoci L, Nagy L, et al. Epidemiology and clinicopathology of aortic dissection. Chest. 2000; 117(5):1271-1278.
- Sullivan PR, Wolfson AB, Leckey RD, Burke JL. Diagnosis of acute thoracic aortic dissection in the emergency department. Am J Emerg Med. 2000; 18(1):46-50.
- Murai T. Aortic dissection and sudden deathstatistical analysis on 1320 cases autopsied at Tokyo-to Medical Examiner Office [in Japanese]. Nihon Houigaku Zasshi. 1988; 42(6):564-577.
- Nienaber CA, Spielmann RP, von Kodolitsch Y, et al. Diagnosis of thoracic aortic dissection. Magnetic resonance imaging versus transesophageal echocardiography. Circulation. 1992; 85(2):434-447.
Drs Yoshioka, Kawahara, and Tomita are from the Department of Orthopedic Surgery, School of Medicine, Kanazawa University, Kanazawa, and Dr Toribatake is from the Department of Orthopedic Surgery, Kouseiren Takaoka Hospital, Takaoka, Japan.
Drs Yoshioka, Toribatake, Kawahara, and Tomita have no relevant financial relationships to disclose.
Correspondence should be addressed to: Katsuhito Yoshioka, MD, Department of Orthopedic Surgery, School of Medicine, Kanazawa University, 13-1 Takaramachi, Kanazawa 920-8641, Japan.