- Email: [email protected]
Abdominal aortic coarctation associated with multiple intracranial aneurysms
European Journal of Radiology Extra 46 (2003) 38 /41 http://intl.elsevierhealth.com/journals/ejrx
Abdominal aortic coarctation associated with multiple intracranial aneurysms Ali Ahmetog˘lu *, Polat Kos¸ucu, Ahmet Sari, Halit Res¸it Gu¨mele Department of Radiology, Faculty of Medicine, Karadeniz Technical University, 61080 Trabzon, Turkey Received 2 May 2002; received in revised form 23 July 2002; accepted 26 July 2002
Abstract Abdominal aortic coarctation is an uncommon vascular disease, representing 0.5 /2% of aortic coarctations. Intracranial aneurysm is rare in childhood and adolescence period. We report an 18-year-old hypertensive boy with abdominal aortic coarctation associated with multiple intracranial aneurysms demonstrated by computed tomography (CT) angiography. # 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Abdominal aortic coarctation; Hypertension; Intracranial aneurysms; Computed tomography angiography
1. Introduction Abdominal aortic coarctation (AAC) is an uncommon vascular disease with stenosis of abdominal aorta commonly involving renal and visceral arteries. Most of the patients have severe hypertension. Intracranial aneurysm associated with AAC is extremely rare and to our knowledge only three cases were reported in the literature [1 /3]. We report herein an 18-year-old hypertensive boy with AAC, renal and visceral artery stenosis who presented with subarachnoid hemorrhage caused by rupture of middle cerebral artery aneurysm.
2. Case report An 18-year-old boy was admitted to our emergency department with the complaint of severe headache. On neurological examination, patient had nuchal rigidity but findings were otherwise normal. Blood pressure was 200/130 mm Hg. Patient underwent computed tomography (CT) that revealed subarachnoid hemorrhage but no aneurysm was observed. CT angiography was performed with multidetector CT (Siemens Volume
* Corresponding author. Tel.: /90-462-377-5553; fax: /90-462225-0518 E-mail address: [email protected] (A. Ahmetog˘lu).
Zoom, Erlangen, Germany) to evaluate subarachnoid hemorrhage with the following parameters: 120 cc nonionic contrast agent, 3 cc/s with automatic injector, 20 s delay, slice thickness, 1.25 mm; collimation, 4 /1 mm; table speed, 5 mm/s; reconstruction index, 1 mm. CT angiography images were produced in virtuoso workstation with volume rendering technique and revealed 4 /3 mm saccular aneurysm with lobulated contour on the bifurcation of right middle cerebral artery and 2 /2 mm saccular aneurysm on the bifurcation of the left middle cerebral artery (Fig. 1). Surgery was performed and aneurysm on the right middle cerebral artery was successfully clipped. After surgery blood pressure of the patient remained high and could not be controlled with medication. Because of high blood pressure, patient underwent renal CT angiography to evaluate renal arteries. Renal CT angiography was performed with the same CT scanner with the following parameters: slice thickness, 1.25 mm; collimation, 4 /1 mm; table speed, 6 mm/s; reconstruction index, 1 mm. Images were obtained 30 s after the start of injection of 120 ml nonionic contrast agent at the flow rate of 3 ml/s. CT angiography was produced on virtuoso workstation with volume rendering technique and revealed 6 cm long narrowed segment of the abdominal aorta beginning from the celiac artery level. Patient also had bilateral stenosis in the proximal part of the renal arteries, celiac artery and superior mesenteric
1571-4675/03/$ - see front matter # 2002 Elsevier Science Ireland Ltd. All rights reserved. doi:10.1016/S1571-4675(03)00040-3
A. Ahmetog ˘ lu et al. / European Journal of Radiology Extra 46 (2003) 38 /41
39
Fig. 1. Cranial CT angiography shows 4 /3 mm saccular aneurysm with lobulated contour on the bifurcation of the right middle cerebral artery and 2 /2 mm saccular aneurysm on the bifurcation of the left middle cerebral artery.
artery (Figs. 2 and 3). Common hepatic artery was hypoplasic. There were also collateral arteries between the superior and inferior mesenteric arteries (Fig. 4).
Fig. 3. Renal BT angiography shows stenosis at the proximal part of superior mesenteric artery and celiac trunk.
3. Discussion Aortic coarctation is an abnormal narrowing of aorta, most commonly affecting thoracic segment. However 0.5 /2% of the coarctation affect abdominal aorta, renal and visceral arteries are also affected in most cases [4].
Fig. 2. Renal BT angiography shows coarctation of abdominal aorta at the interrenal level and patient also have stenosis at the proximal part of the both renal arteries.
Fig. 4. Renal BT angiography shows dilated Riolan arcade arising from inferior mesenteric artery.
40
A. Ahmetog ˘ lu et al. / European Journal of Radiology Extra 46 (2003) 38 /41
Abdominal aortic coarctation is frequently diagnosed in younger age group with mean age of 21 [5]. Most common location of narrowing as in our case is interrenal location occurring in 52% of the cases. Narrowing is isolated to the suprarenal region in 11%, infrarenal aorta in 25% of the cases. Remaining 12% of the patients have diffuse aortic involvement [6]. Stenosis of the renal arteries is also seen in 81% of the patients and splanchnic arterial involvement is noted in 22% of the cases [6]. Signs and symptoms are related to location of the lesion and involvement of the renal arteries. Coarctations below the renal arteries produce primarily leg discomfort. But narrowing above renal arteries produce hypertension. Hypertension is more severe if renal arterial stenosis is also present. Mesenteric ischemia is very uncommon because of hemodynamic compensation between the mesenteric arteries. If untreated, patients generally die because of cardiac failure or cerebral hemorrhage in the third decade of the life [7]. Most of the patients are diagnosed in childhood period, but the lesion may occur in the fifth or sixth decade of the life. That is why there is controversy about the pathogenesis of AAC whether it is congenital or acquired. Most accepted theory, which was proposed by Maycock, suggests that AAC is a congenital disease and caused by an unequal fusion of the primitive dorsal aorta with subsequent obliteration of one of them [8]. Developmental overfusion of the fetal aorta was also proposed as an alternative hypothesis [9]. Other pathologies including neurofibromatosis, fibromuscular dysplasia, tuberculosis, nonspecific arteritis such as takayasu can also lead to AAC [10 /12]. But in most of the cases, it is impossible to define the main causes because the end stage pathology is generally nonspecific and shows similar appearance. Other than segmental narrowing of vessels, 5% of the cases have visceral aneurysm [6]. Cerebral aneurysm is extremely rare. To our knowledge, only three cases of AAC associated with aneurysm have been reported before. In one of these reported cases, aneurysm was observed at the autopsy [1]. In the other two cases, aneurysms were diagnosed with cerebral angiography because of subarachnoid hemorrhage [2,3]. In our case, diagnosis of cerebral aneurysms and aortic coarctation were made by CT angiography. More than 500 cases of AAC were reported in the literature but only four cases (including our case) were reported to have subarachnoid hemorrhage due to aneurysm. Cerebral angiography was not performed to other reported cases because of lack of neurological symptom. So true incidence of aneurysm in AAC is not known. Many studies suggest that aneurysm formation, growth, and rupture are predominantly related to flow dynamics but it is still not known if hypertension has a primary role in the formation of intracranial aneurysm. Rinne et al. found
Fig. 5. A drawing showing common sites of hemodynamic aneurysms.
significant correlation between multiple aneurysms and hypertension [13]. They concluded that hypertension increases the risk of multiple aneurysms formation if other factors are present. Our patient also had two aneurysms on the bifurcation of the middle cerebral arteries. Endothelial injury, degeneration of internal elastic lamina, and thinning of the media smooth muscle cells are early signs of aneurysm [14]. Chronic hypertension causes intimal thickening, medial necrosis, changes in the matrix composition and degeneration of internal elastic lamina and these structural changes would likely lead to focal dilatation and initial bulging of the arterial wall [15]. Injury to the internal elastic lamina by hemodynamic forces is the initial pathophysiological alteration [15]. Hypertension is a hemodynamic abnormality. Because arterial bifurcations are the site of greatest shear forces against the arterial wall, such injury occurs at the bifurcations of major arteries. That is why most common locations of the saccular aneurysms are anterior and posterior communicating arteries and bifurcation of middle cerebral arteries (Fig. 5). We don’t know if hypertension played a primary role in the formation of saccular aneurysms in our patient, but because the average age of patients with subarachnoid hemorrhage is low in AAC, it is clear that hypertension plays a role at least in the growth and rupture of cerebral aneurysm in AAC.
References [1] Fisher ER, Corcoran AC. Congenital coarctation of abdominal aorta with resultant renal arterial stenosis. AMA Arch Int Med 1952;89:943 /50. [2] Ishii K, Isono M, Kasai N, et al. Midaortic syndrome with a ruptured cerebral aneurysm: a case report. Surg Neurol 2001;55:209 /12.
A. Ahmetog ˘ lu et al. / European Journal of Radiology Extra 46 (2003) 38 /41 [3] Blidzac J, Bargainer JD. Coarctation of the abdominal aorta with aneurysm of middle cerebral artery. Am J Roentgenol Radium Ther Nuci Med 1974;122:29 /32. [4] Paroni R, Astuni M, Baroni C, et al. Abdominal aortic coarctation including aortic occlusion and renovascular hypertension. J Cardiovasc Surg 1991;32:770 /4. [5] Sproul D, Pinto J. Coarctation of abdominal aorta. Arch Surg 1972;105:571 /3. [6] Graham LM, Zelenoch GB, Erlandson EE, Coran AG, Lindenauer SM, Stanley JC. Abdominal aortic coarctation and segmental hypoplasia. Surgery 1979;86:519 /29. [7] Baird R, Evans JR, Labrusse CL. Coarctation of abdominal aorta. Arch Surg 1964;89:466 /8. [8] Maycock W. Congenital stenosis of the abdominal aorta. Am Heart J 1937;13:633 /46. [9] Stanley FC, Graham LM, Whitehouse WM, et al. Developmental occlusive disease of the abdominal aorta and the splanchnic and
41
renal arteries. Am J Surg 1981;142:190 /6. [10] Hata J, Hosoda Y. Tubuler stenosis of the aorta with aortic fibromuscular dysplasia. Arch Pathol Lab Med 1976;100:652 /5. [11] Lande A. Takayasu’s arteritis and congenital coarctation of the descending thoracic and abdominal aorta. A critical review. Am J Roentgenol 1976;127:227 /33. [12] Schurch W, Messerli FH, Genesth J, et al. Arterial hypertension and neurofibromatosis: renal artery stenosis and coarctation of abdominal aorta. Can Med Assoc 1975;113:879 /85. [13] Rinne J, Hernesniemi J, Puranen M, Saari T. Multiple intracranial aneurysms in a defined population: prospective angiographic and clinical study. Neurosurgery 1994;35:803 /8. [14] Stehbens WE. Histopathology of cerebral aneurysm. Arch Neurol 1963;8:272 /85. [15] Inci S, Spetzler RF. Intracranial aneurysms and arterial hypertension: a review and hypothesis. Surg Neurol 2000;53:530 /42.
Abdominal aortic coarctation associated with multiple intracranial aneurysms Ali Ahmetog˘lu *, Polat Kos¸ucu, Ahmet Sari, Halit Res¸it Gu¨mele Department of Radiology, Faculty of Medicine, Karadeniz Technical University, 61080 Trabzon, Turkey Received 2 May 2002; received in revised form 23 July 2002; accepted 26 July 2002
Abstract Abdominal aortic coarctation is an uncommon vascular disease, representing 0.5 /2% of aortic coarctations. Intracranial aneurysm is rare in childhood and adolescence period. We report an 18-year-old hypertensive boy with abdominal aortic coarctation associated with multiple intracranial aneurysms demonstrated by computed tomography (CT) angiography. # 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Abdominal aortic coarctation; Hypertension; Intracranial aneurysms; Computed tomography angiography
1. Introduction Abdominal aortic coarctation (AAC) is an uncommon vascular disease with stenosis of abdominal aorta commonly involving renal and visceral arteries. Most of the patients have severe hypertension. Intracranial aneurysm associated with AAC is extremely rare and to our knowledge only three cases were reported in the literature [1 /3]. We report herein an 18-year-old hypertensive boy with AAC, renal and visceral artery stenosis who presented with subarachnoid hemorrhage caused by rupture of middle cerebral artery aneurysm.
2. Case report An 18-year-old boy was admitted to our emergency department with the complaint of severe headache. On neurological examination, patient had nuchal rigidity but findings were otherwise normal. Blood pressure was 200/130 mm Hg. Patient underwent computed tomography (CT) that revealed subarachnoid hemorrhage but no aneurysm was observed. CT angiography was performed with multidetector CT (Siemens Volume
* Corresponding author. Tel.: /90-462-377-5553; fax: /90-462225-0518 E-mail address: [email protected] (A. Ahmetog˘lu).
Zoom, Erlangen, Germany) to evaluate subarachnoid hemorrhage with the following parameters: 120 cc nonionic contrast agent, 3 cc/s with automatic injector, 20 s delay, slice thickness, 1.25 mm; collimation, 4 /1 mm; table speed, 5 mm/s; reconstruction index, 1 mm. CT angiography images were produced in virtuoso workstation with volume rendering technique and revealed 4 /3 mm saccular aneurysm with lobulated contour on the bifurcation of right middle cerebral artery and 2 /2 mm saccular aneurysm on the bifurcation of the left middle cerebral artery (Fig. 1). Surgery was performed and aneurysm on the right middle cerebral artery was successfully clipped. After surgery blood pressure of the patient remained high and could not be controlled with medication. Because of high blood pressure, patient underwent renal CT angiography to evaluate renal arteries. Renal CT angiography was performed with the same CT scanner with the following parameters: slice thickness, 1.25 mm; collimation, 4 /1 mm; table speed, 6 mm/s; reconstruction index, 1 mm. Images were obtained 30 s after the start of injection of 120 ml nonionic contrast agent at the flow rate of 3 ml/s. CT angiography was produced on virtuoso workstation with volume rendering technique and revealed 6 cm long narrowed segment of the abdominal aorta beginning from the celiac artery level. Patient also had bilateral stenosis in the proximal part of the renal arteries, celiac artery and superior mesenteric
1571-4675/03/$ - see front matter # 2002 Elsevier Science Ireland Ltd. All rights reserved. doi:10.1016/S1571-4675(03)00040-3
A. Ahmetog ˘ lu et al. / European Journal of Radiology Extra 46 (2003) 38 /41
39
Fig. 1. Cranial CT angiography shows 4 /3 mm saccular aneurysm with lobulated contour on the bifurcation of the right middle cerebral artery and 2 /2 mm saccular aneurysm on the bifurcation of the left middle cerebral artery.
artery (Figs. 2 and 3). Common hepatic artery was hypoplasic. There were also collateral arteries between the superior and inferior mesenteric arteries (Fig. 4).
Fig. 3. Renal BT angiography shows stenosis at the proximal part of superior mesenteric artery and celiac trunk.
3. Discussion Aortic coarctation is an abnormal narrowing of aorta, most commonly affecting thoracic segment. However 0.5 /2% of the coarctation affect abdominal aorta, renal and visceral arteries are also affected in most cases [4].
Fig. 2. Renal BT angiography shows coarctation of abdominal aorta at the interrenal level and patient also have stenosis at the proximal part of the both renal arteries.
Fig. 4. Renal BT angiography shows dilated Riolan arcade arising from inferior mesenteric artery.
40
A. Ahmetog ˘ lu et al. / European Journal of Radiology Extra 46 (2003) 38 /41
Abdominal aortic coarctation is frequently diagnosed in younger age group with mean age of 21 [5]. Most common location of narrowing as in our case is interrenal location occurring in 52% of the cases. Narrowing is isolated to the suprarenal region in 11%, infrarenal aorta in 25% of the cases. Remaining 12% of the patients have diffuse aortic involvement [6]. Stenosis of the renal arteries is also seen in 81% of the patients and splanchnic arterial involvement is noted in 22% of the cases [6]. Signs and symptoms are related to location of the lesion and involvement of the renal arteries. Coarctations below the renal arteries produce primarily leg discomfort. But narrowing above renal arteries produce hypertension. Hypertension is more severe if renal arterial stenosis is also present. Mesenteric ischemia is very uncommon because of hemodynamic compensation between the mesenteric arteries. If untreated, patients generally die because of cardiac failure or cerebral hemorrhage in the third decade of the life [7]. Most of the patients are diagnosed in childhood period, but the lesion may occur in the fifth or sixth decade of the life. That is why there is controversy about the pathogenesis of AAC whether it is congenital or acquired. Most accepted theory, which was proposed by Maycock, suggests that AAC is a congenital disease and caused by an unequal fusion of the primitive dorsal aorta with subsequent obliteration of one of them [8]. Developmental overfusion of the fetal aorta was also proposed as an alternative hypothesis [9]. Other pathologies including neurofibromatosis, fibromuscular dysplasia, tuberculosis, nonspecific arteritis such as takayasu can also lead to AAC [10 /12]. But in most of the cases, it is impossible to define the main causes because the end stage pathology is generally nonspecific and shows similar appearance. Other than segmental narrowing of vessels, 5% of the cases have visceral aneurysm [6]. Cerebral aneurysm is extremely rare. To our knowledge, only three cases of AAC associated with aneurysm have been reported before. In one of these reported cases, aneurysm was observed at the autopsy [1]. In the other two cases, aneurysms were diagnosed with cerebral angiography because of subarachnoid hemorrhage [2,3]. In our case, diagnosis of cerebral aneurysms and aortic coarctation were made by CT angiography. More than 500 cases of AAC were reported in the literature but only four cases (including our case) were reported to have subarachnoid hemorrhage due to aneurysm. Cerebral angiography was not performed to other reported cases because of lack of neurological symptom. So true incidence of aneurysm in AAC is not known. Many studies suggest that aneurysm formation, growth, and rupture are predominantly related to flow dynamics but it is still not known if hypertension has a primary role in the formation of intracranial aneurysm. Rinne et al. found
Fig. 5. A drawing showing common sites of hemodynamic aneurysms.
significant correlation between multiple aneurysms and hypertension [13]. They concluded that hypertension increases the risk of multiple aneurysms formation if other factors are present. Our patient also had two aneurysms on the bifurcation of the middle cerebral arteries. Endothelial injury, degeneration of internal elastic lamina, and thinning of the media smooth muscle cells are early signs of aneurysm [14]. Chronic hypertension causes intimal thickening, medial necrosis, changes in the matrix composition and degeneration of internal elastic lamina and these structural changes would likely lead to focal dilatation and initial bulging of the arterial wall [15]. Injury to the internal elastic lamina by hemodynamic forces is the initial pathophysiological alteration [15]. Hypertension is a hemodynamic abnormality. Because arterial bifurcations are the site of greatest shear forces against the arterial wall, such injury occurs at the bifurcations of major arteries. That is why most common locations of the saccular aneurysms are anterior and posterior communicating arteries and bifurcation of middle cerebral arteries (Fig. 5). We don’t know if hypertension played a primary role in the formation of saccular aneurysms in our patient, but because the average age of patients with subarachnoid hemorrhage is low in AAC, it is clear that hypertension plays a role at least in the growth and rupture of cerebral aneurysm in AAC.
References [1] Fisher ER, Corcoran AC. Congenital coarctation of abdominal aorta with resultant renal arterial stenosis. AMA Arch Int Med 1952;89:943 /50. [2] Ishii K, Isono M, Kasai N, et al. Midaortic syndrome with a ruptured cerebral aneurysm: a case report. Surg Neurol 2001;55:209 /12.
A. Ahmetog ˘ lu et al. / European Journal of Radiology Extra 46 (2003) 38 /41 [3] Blidzac J, Bargainer JD. Coarctation of the abdominal aorta with aneurysm of middle cerebral artery. Am J Roentgenol Radium Ther Nuci Med 1974;122:29 /32. [4] Paroni R, Astuni M, Baroni C, et al. Abdominal aortic coarctation including aortic occlusion and renovascular hypertension. J Cardiovasc Surg 1991;32:770 /4. [5] Sproul D, Pinto J. Coarctation of abdominal aorta. Arch Surg 1972;105:571 /3. [6] Graham LM, Zelenoch GB, Erlandson EE, Coran AG, Lindenauer SM, Stanley JC. Abdominal aortic coarctation and segmental hypoplasia. Surgery 1979;86:519 /29. [7] Baird R, Evans JR, Labrusse CL. Coarctation of abdominal aorta. Arch Surg 1964;89:466 /8. [8] Maycock W. Congenital stenosis of the abdominal aorta. Am Heart J 1937;13:633 /46. [9] Stanley FC, Graham LM, Whitehouse WM, et al. Developmental occlusive disease of the abdominal aorta and the splanchnic and
41
renal arteries. Am J Surg 1981;142:190 /6. [10] Hata J, Hosoda Y. Tubuler stenosis of the aorta with aortic fibromuscular dysplasia. Arch Pathol Lab Med 1976;100:652 /5. [11] Lande A. Takayasu’s arteritis and congenital coarctation of the descending thoracic and abdominal aorta. A critical review. Am J Roentgenol 1976;127:227 /33. [12] Schurch W, Messerli FH, Genesth J, et al. Arterial hypertension and neurofibromatosis: renal artery stenosis and coarctation of abdominal aorta. Can Med Assoc 1975;113:879 /85. [13] Rinne J, Hernesniemi J, Puranen M, Saari T. Multiple intracranial aneurysms in a defined population: prospective angiographic and clinical study. Neurosurgery 1994;35:803 /8. [14] Stehbens WE. Histopathology of cerebral aneurysm. Arch Neurol 1963;8:272 /85. [15] Inci S, Spetzler RF. Intracranial aneurysms and arterial hypertension: a review and hypothesis. Surg Neurol 2000;53:530 /42.