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Traumatic occlusion in fibromuscular dysplasia of the carotid artery
Traumatic Occlusion in Fibromuscular Dysplasia of the Carotid Artery Paul H. Young, M.D., Kenneth R. Smith, Jr., M.D., David C. Crafts, M.D., and Hendrick B. Bamer, M.D.
A patient with fibromuscular dysplasia involving the cervical carotid artery developed subtotal occlusion after a trivial head injury. An association between occlusion in fibromuscular dysplasia-diseased carotid arteries and trivial blunt head injuries is suggested and appropriate treatment options are discussed. Young PH, Smith KR Jr, Crafts DC, Barner HB: Traumatic occlusionin fibromusculardysplasiaof the carotid artery. SurgNeurol 16:432-437, 1981 Fibromuscular dysplasia and traumatic carotid artery occlusion are both nonatherosclerotic arteriopathies that commonly obstruct the arterial lumen due to intimal flaps with medial dissection and thrombus formation. Both conditions often affect a similar segment of the cervical carotid artery. We report a case of traumatic occlusion of the cervical carotid artery in a patient with preexisting fibromuscular dysplasia. Case Report A 53-year-old, right-handed, previously hypertensive, white woman was involved in a minor traffic accident on March 18, 1979. She struck the dashboard and suffered several cracked ribs and a contusion on the left side of her forehead. She never lost consciousness, and neurological examination upon admission to an outlying hospital was totally normal. There was no apparent direct injury to the neck. About eighteen hours after the accident, her family noticed that she seemed confused and had some difficulty speaking. Her symptoms fluctuated but over the next twenty-four hours gradually worsened to the point that she could not speak or use her right arm or leg. She was admitted on March 20 to St. Louis University Hospital for further evaluation. An immediate computed tomographic (CT) scan reFrom the Department of Surgery, Section of NeurologicalSurgery, St. Louis University, St. Louis, M©. Address reprint requests to Dr. Paul H. Young, Department of Neurosurgery, St. Louis University Hospitals, 1325 South Grand Blvd., St. Louis, MO 63104. Key words: trauma; carotid artery occlusion; fibromuscular dysplasia; pathophysiology;treatment.
vealed several small isolated round areas of decreased density in the left temporal and parietal lobes without mass effect (Fig. 1). These were thought to be areas of embolic infarction. Cerebral angiography revealed subtotal occlusion of the left internal carotid artery at the level of the atlas and delayed filling of the left middle cerebral artery (Fig. 2A). Nonfilling of the distal A1 segment of the left anterior cerebral artery and the absence of several left middle cerebral artery branches were indicative of propagated embolic occlusion (Fig. 2B). A classic "string of beads" [19] pattern suggestive of fibromuscular dysplasia was evident immediately proximal to the occlusion in the left internal carotid artery (Fig. 2C). The right carotid circulation was normal except for a hint of mild fibromuscular dysplasia in the midportion of the right internal carotid artery. The patient was immediately heparinized and taken to the operating room. A transverse incision was made in a skin crease just below the mandible from immediately anterior to the left sternocleidomastoid muscle to the mastoid process. The entire length of the left cervical internal carotid artery from the carotid bifurcation to the base of the skull was dissected free without dividing the mandible. At the point of occlusion, the external surface of the artery appeared ecchymotic. There was no arterial pulsation distal to the occlusion, and after arteriotomy there was no back-bleeding from the intracranial carotid artery. A No. 4 French Fogarty catheter was carefully threaded several times into the distal internal carotid artery and some propagated thrombus was retrieved. Excellent back-bleeding followed. A Sundt shunt was inserted around the occlusion. At the area of injury, there were several large intimal tears, with dissection into the media, flap formation, and thrombosis. The media was visibly thickened in several areas and seemed to separate almost spontaneously from the adventitia. A localized endarterectomy was performed and hyperplastic media and intimal flaps were removed. Several tacking sutures were applied to the distal, apparently normal, intimal edge to prevent further anterograde dissection. The arteriotomy was closed and excellent distal arterial pulsations were restored. Intraoperative arteriography revealed no residual occlusion and good intracranial circulation. Postoperatively the patient's neurological status slowly
432 0090-3019/81/120432-06501.25 © 1981 by Little, Brown and Company (Inc.)
Young et al: Fibromuscular Dysplasia
Fig, 1. Contrast-enhanced CT scans obtained upon admission showing several distinct round areas of decreased density in the left temporal and parietal lobes without mass effect (arrows).
433
434 SurgicalNeurology Vol 16 No 6 December 1981
A
C
Fig. 2. Left carotid angmgram obtained shortly after admission. ( A) Subtotal occlusion of the left internal carotid artery at the level of the atlas with dramatically decreased left middle cerebral artery. flow. (B) Total occlusion of left A , segment of anterior cerebral artery (embolic). ( C) Classic "string of beads" pattern pathognomonic of fibromuscular dysplasia in midportion of left internal carotid artery.
improved. By ten days after the operation, she could answer questions coherently and move her right arm almost normally. Repeat angiography revealed good flow past the area of previous occlusion and excellent filling of the left middle and anterior cerebral arteries. However, subtraction films of the left cervical carotid artery revealed areas of tight stenosis alternating with aneurysma[ dilatations that were pathognomonic of severe fibromuscular dysplasia (Fig. 3). The patient's neurological status continued to improve
slowly. Four weeks after the original operation, her only neurological deficit was a mild nominal dysphasia. At this point the patient was returned to the operating room and a saphenous vein autogenous jump graft was performed from the left carotid bifurcation to the distal left cervical internal carotid artery. Postoperative arteriography revealed a patent reconstruction without stenosis and excellent filling of the intracranial circulation (Fig. 4). The patient did well after this procedure and was sent
Young et ah Fibromuscular Dysplasia 435
i~iil ~ ~~ i~:~
ii ~'~
~
P i
ii I
Fig. 3. Left carotid angiogram (subtractions) obtained ten days after initial operation showing no residual occlusion but several areas of tight stenosis alternating with areas of aneurysmal dilatation indicative of severe fibromuscular dysplasia.
Fig. 4. Postoperative left carotid an~ogram performed after completion of autogenous saphenous vein bypass graft. Good filling of bypass graft and internal carotid artery is evident.
home in a few days with the same mild dysphasia. When last seen about five months after the operation, she had resumed normal activities. Her only neurological defect was mild hoarseness, probably caused by injury to the vagus nerve.
of fibromuscular dysplasia have been discovered incidentally during angiography for reasons other than cerebral ischemia [2, 7]. Until recently, fibromuscular dysplasia has been considered an important arterial disease more because of its association with intracranial aneurysms [9, 20] than as a cause of cerebral ischemia. However, several recent reports show that fibromuscular dysplasia can be associated with significant neurological disease [10, 23, 25], including recurrent cerebral ischemia [5, 6]. The static and benign natural history of fibromuscular dysplasia is now suspect; several reports clearly demonstrate slow but definite progression of the disease [7, 12]. Furthermore, large series of patients with symptoms of cerebral ischemia incriminate fibromuscular dysplasia as one of the more common nonatherosclerotic causes of carotid
Discussion Fibromuscular dysplasia is a generalized arteriopathy affecting small to medium-sized vessels. For many years it was known primarily as a curable cause of systemic hypertension resulting from involvement of the renal arteries [21]. In 1965, fibromuscular dysplasia was first described in the carotid artery, and a causal relationship between fibromuscular dysplasia and cerebral ischemic episodes was initially suggested [4]. However, the vast majority of reported cases
436
Surgical Neurology Vol 16 No 6 December 1981
stenosis [14]. Thus fibromuscular dysplasia is assuming an injury. Fibromuscular dysplasia-diseased intraabdominal increasingly important role in cerebrovascular disease. vessels seem susceptible to spontaneous dissection and Fibromuscular dysplasia is easily identified on radiog- (traumatic) occlusion [22]. A recent report by Ringel and raphy by multiple arterial dilatations alternating with ir- associates [24] describes a skier who suffered supposedly regularly spaced concentric stenosis, the pathognomonic traumatic dissections of both carotid and both vertebral ar"string of beads" pattern [19]. This conforms to the gross teries, all afflicted with fibromuscular dysplasia. Our patient appearance of the disease process, i.e., medial thickening had severe fibromuscular dysplasia of the left internal causing multiple stenotic segments alternating with focal carotid artery and mild disease of the right internal carotid outpouchings secondary to aneurysmal dilatation [27]. artery. She suffered traumatic cervical carotid artery occluMicroscopically the thickened media usually is related to sion of the more seriously involved artery after a seemingly disorganized fibroplasia; the dilatations are caused by dis- trivial blunt head injury. Many other cases of acute occluruption of the elastic membranes [27]. sion in fibromuscular dysplasia-diseased arteries may have Almost without exception, fibromuscular dysplasia of the been related to unrecognized trivial arterial injury. Thus it carotid artery occurs in the distal cervical carotid artery ad- seems possible that repeated mild vascular injury may play a jacent to the uppermost cervical vertebrae [19]. This par- role not only in the pathogenesis of fibromuscular dysplasia ticular segment of the carotid artery is intimately related to but also in eventual arterial occlusion and stroke. the bony prominences of the upper two cervical vertebrae. The usual treatment of fibromuscular dysplasia involving Thus during normal extension and rotation of the head, the carotid artery is individualized. Graduated internal dithis segment of internal carotid artery is particularly prone latation [15], endarterectomy with patch graft [23], resecto stretching and shearing around the bony margins [3]. tion of the diseased segment with end-to-end anastomosis The pathogenesis of fibromuscular dysplasia may be related [5], and autogenous venous jump grafts [4] have all been to this repeated traction on the carotid artery, predisposing used successfully. After traumatic cervical carotid artery octo disruption of the vasa vasorum [16, 27] and medial clusion with embolic symptoms but good collateral circulafibroplasia [27]. tion, anticoagulation and carotid occlusion may be conTraumatic cervical carotid artery occlusion in the ab- sidered. In the absence of good collateral circulation, sence of direct injury or previous disease is also generally thrombectomy with endarterectomy [14], resection, or confined to this same segment of artery. During even mild bypass graft seems warranted [26]. Other revascularization blunt injuries to the head with resultant sudden hyperten- procedures, including superficial temporal-middle cerebral sion or rotation of the neck, or both, this portion of the artery anastomoses, may be necessary in certain instances carotid artery is forcibly strained around the atlantoaxial [1]. bony prominences [13]. The delicate arterial intima can thereby be disrupted, causing intimal flap formation, medial dissection, and finally thrombosis [17]. Symptomatic References 1. Aarabi B, McQueen JD: Traumatic internal carotid occlusion at the traumatic cervical carotid artery occlusion in previously base of the skull. Surg Neurol 10:233-236, 1978 healthy arteries is certainly rare [11], although some degree 2. Anderson PE: Fibromuscularhyperplasiaof the carotid arteries. Acta of intimal injury may often occur after even minor Radiol [Diagn] (Stockh) 10:90-96, 1970 3. Boldrey E, Maass L, Miller ER: Role of atlantoid compression in craniocerebral trauma [18]. However, unless thrombosis etiology of internal carotid artery thrombosis. J Neurosurg 13:127with cerebral emboli or complete occlusion with inadequate 139, 1956 collateral circulation occurs, the patient may well be 4. Connett MC, LanscheJM: FibromuscularhyperplasiaOfthe internal carotid artery. Ann Surg 162:59-62, 1965 asymptomatic [8, 18]. 5. Ehrenfeld WK, Stoney RJ, Wylie EJ: Fibromuscular hyperplasiaof Symptomatic traumatic cervical carotid artery occlusion internal carotid artery. Arch Surg 95:284-287, 1967 in the atlantoaxial portion of the artery should occur more 6. Ehrenfeld WK, Wylie EJ: Fibromuscular dysplasia of the internal carotid artery. Arch Surg 109:676-681, 1974 frequently in arteries with preexisting disease. Traumatic 7. GalligioniF, lraci G, Marin G: Fibromuscularhyperplasiaof the excervical carotid artery occlusion at the bifurcation is seen tracranial internal carotid artery. J Neurosurg 34:647-651, 1971 often in association with preexisting atherosclerotic disease 8. GurdjianES, HardyWG, Lindner DW, ThomasLM: Closedcervical cranial trauma associated with involvementof carotid and vertebral [28]. Similarly, diseased segments of artery adjacent to arteries. J Neurosurg 20:418-427, 1963 bony protuberances seem more susceptible to even trivial 9. HandaJ, KamijyoY, Handa H: lntracranial aneurysmassociatedwith stretching and tearing of the intima or plaque, medial disfibromuscular-hyperplasiaof renal and internal carotid arteries. Br J Radiol 43:483-485, 1970 section, and thrombosis [ 17]. Thus patients with upper cer10. Hartman JD, Young 1, Bank AA, Rosenblott SA: Fibromuscular vical carotid artery atherosclerosis may be more vulnerable hyperplasia of internal carotid arteries: stroke in a young adult comto injury to the vessel and occlusion after trivial blunt head plicated by oral contraceptives. Arch Neurol 25:295-301, 1971 11. Higazi1: Post-traumaticcarotid thrombosis. J Neurosurg 20:354-359, injury. 1963 Along these lines, fibromuscular dysplasia of the atlanto- 12. Kincaid OW, Davis GD, Hallermann FJ, Hunt JC: Fibromuscular dysplasia of renal arteries. Am J Roentgenol 104:271-282, 1968 axial carotid artery may predispose this segment of vessel to
Young et al: Fibromuscular Dysplasia 437
13. Little JM, Vanderfield GK, May J, Lamont S: Traumatic thrombosis of internal carotid artery. Lancet 2:926-930, 1969 14. MomoseKJ, New PF: Non-atheromatous stenosis and occlusion of the internal carotid artery and its main branches. Am J Roentgenol 118:550-566, 1973 15. Morris GC, Lechter A, DeBakeyME: Surgical treatment of fibromuscular diseases of the carotid arteries. Arch Surg 96:636-643, 1967 16. Nakata Y: An experimental study on the vascular lesions caused by obstruction of the vasa vasorum. Jpn Circ J 31:275-287, 1967 17. New PF, Momose KJ: Traumatic dissection of the internal carotid artery at the atlantoaxial level secondary to non-penetrating injury. Radiology 93:41-49, 1969 18. Olafson RA, Christoferson LE: The syndrome of carotid occlusion following minor craniocerebral trauma. J Neurosurg 33:636-639, 1970 19. Osburn AG, Anderson RE: Angiographic spectrum of cervical and intracranial fibromusculardysplasia. Stroke 8:617-626, 1977 20. Palubinskas AJ, Perloff D, Newton TH: Fibromuscular hyperplasia--an arterial dysplasia of increasing clinical importance. Am J Roentgenol 98:907-913, 1966
21. Palubinskas AJ, Perloff D, Wylie EJ: Curable hypertension due to renal artery lesions. Radiol Clin North Am 33:209-216, 1964 22. Perry MO: Fibromuscular disease of carotid artery. Surg Gynecol Obstet 134:57-60, 1972 23. Rainer GW, Cramer GG, Newby JP, Clarke JP: Fibromuscular hyperplasia of carotid artery causing positional cerebral ischemia. Ann Surg 167:44, 1968 24. Ringel SP, Harrison SH, Norenberg MD, Austin JH: Fibromuscular dysplasia: multiple "spontaneous" aneurysms of major cervical arteries. Ann Neurol 1:301-304, 1977 25. Sandok BA, Houser OW, Baker HL, Holley KE: Fibromuscular dysplasia: neurologic disorders associated with disease involving the great vessels in the neck. Arch Neurol 24:462-466, 1971 26. Schneider RC, Gosch HH, Taren JA, Ferry DJ, Jerva MJ: Blood vessel trauma following head and neck injuries. Clin Neurosurg 19:312-354, 1971 27. Stanley JC, Gewertz BL, Beve EL, Sottiurai V, Fry WJ: Arterial fibrodysplasia:histological character and current etiologic concepts. Arch Surg 110:561-566, 1975 28. Yamada S, Kin& GW, Youmans JR: Carotid artery occlusion due to nonpenetrating surgery. J Trauma 7:333-342, 1967
Editorial: Greatness Is Not Geographic For many, many years New England has flourished as the outstanding educational center of the United States. This element of greatness has extended from its private secondary schools, through its liberal arts colleges, and into its medical schools (at least some of them). This measure of greatness has persisted, although at all levels the difference between New England institutions and those in the rest of the country has lessened as institutions elsewhere have improved. T h e outstanding quality of New England institutions has been misinterpreted by some to mean that the young people of New England are also superior to others. This biased view has completely ignored the fact that New England's institutions of higher learning have maintained their position by recruiting their faculties and student bodies from the entire country and abroad. If we look for the m o m e n t at our own specialty--neurological surgery--we see that this is true. Cushing, although Professor at Harvard, came from Ohio; Dandy, Professor at Johns Hopkins, came from Missouri. More recently, William Sweet came from the state of Washington. These are but a few of the many examples illustrating the point that I wish to make. It would be obvious that those medical schools that recruit their faculties and student bodies from the widest possible area are the most outstanding. My personal experience may serve as an example. I attended the University of Iowa. I would have preferred going to Harvard, which had accepted my application, but I could not financially afford to do so. Iowa at that time was a distinctly mediocre institution. It had a few outstanding men on its faculty but most of the faculty were not known outside of that university. Its
student body was recruited largely from the state of Iowa. It was not alone in this position of mediocrity. This lower rung on the ladder of medical education was shared by many other medical schools. It was apparent to everyone that the first rung was occupied by the private schools such as Harvard, Johns Hopkins, and the University of Chicago, which were and which have remained truly national institutions. A l t h o u g h many of the state universities and their medical schools have made great progress in the last half century, others have not. A l l too many of them still restrict their student bodies largely to residents of that particular state. N o institution can restrict its selection of students to any limited group without suffering the consequences. These are all most damaging. We recognize that various states make this restriction on admission to their medical schools on the basis that the state supports the schools and that the benefits which derive from education there should be restricted to the citizens of the state. Such reasoning ignores the fact that many of the doctors who practice within the state, including the members of the faculty of the medical school, have been educated at medical schools that are located outside of the state. This is beneficial to the state and its citizens and is as it should be. States that place a restriction upon entrance to their medical schools must recognize that they are injuring only themselves. They are insuring that their medical school will be inferior. Paul C. Bucy, M . D . , Editor
A patient with fibromuscular dysplasia involving the cervical carotid artery developed subtotal occlusion after a trivial head injury. An association between occlusion in fibromuscular dysplasia-diseased carotid arteries and trivial blunt head injuries is suggested and appropriate treatment options are discussed. Young PH, Smith KR Jr, Crafts DC, Barner HB: Traumatic occlusionin fibromusculardysplasiaof the carotid artery. SurgNeurol 16:432-437, 1981 Fibromuscular dysplasia and traumatic carotid artery occlusion are both nonatherosclerotic arteriopathies that commonly obstruct the arterial lumen due to intimal flaps with medial dissection and thrombus formation. Both conditions often affect a similar segment of the cervical carotid artery. We report a case of traumatic occlusion of the cervical carotid artery in a patient with preexisting fibromuscular dysplasia. Case Report A 53-year-old, right-handed, previously hypertensive, white woman was involved in a minor traffic accident on March 18, 1979. She struck the dashboard and suffered several cracked ribs and a contusion on the left side of her forehead. She never lost consciousness, and neurological examination upon admission to an outlying hospital was totally normal. There was no apparent direct injury to the neck. About eighteen hours after the accident, her family noticed that she seemed confused and had some difficulty speaking. Her symptoms fluctuated but over the next twenty-four hours gradually worsened to the point that she could not speak or use her right arm or leg. She was admitted on March 20 to St. Louis University Hospital for further evaluation. An immediate computed tomographic (CT) scan reFrom the Department of Surgery, Section of NeurologicalSurgery, St. Louis University, St. Louis, M©. Address reprint requests to Dr. Paul H. Young, Department of Neurosurgery, St. Louis University Hospitals, 1325 South Grand Blvd., St. Louis, MO 63104. Key words: trauma; carotid artery occlusion; fibromuscular dysplasia; pathophysiology;treatment.
vealed several small isolated round areas of decreased density in the left temporal and parietal lobes without mass effect (Fig. 1). These were thought to be areas of embolic infarction. Cerebral angiography revealed subtotal occlusion of the left internal carotid artery at the level of the atlas and delayed filling of the left middle cerebral artery (Fig. 2A). Nonfilling of the distal A1 segment of the left anterior cerebral artery and the absence of several left middle cerebral artery branches were indicative of propagated embolic occlusion (Fig. 2B). A classic "string of beads" [19] pattern suggestive of fibromuscular dysplasia was evident immediately proximal to the occlusion in the left internal carotid artery (Fig. 2C). The right carotid circulation was normal except for a hint of mild fibromuscular dysplasia in the midportion of the right internal carotid artery. The patient was immediately heparinized and taken to the operating room. A transverse incision was made in a skin crease just below the mandible from immediately anterior to the left sternocleidomastoid muscle to the mastoid process. The entire length of the left cervical internal carotid artery from the carotid bifurcation to the base of the skull was dissected free without dividing the mandible. At the point of occlusion, the external surface of the artery appeared ecchymotic. There was no arterial pulsation distal to the occlusion, and after arteriotomy there was no back-bleeding from the intracranial carotid artery. A No. 4 French Fogarty catheter was carefully threaded several times into the distal internal carotid artery and some propagated thrombus was retrieved. Excellent back-bleeding followed. A Sundt shunt was inserted around the occlusion. At the area of injury, there were several large intimal tears, with dissection into the media, flap formation, and thrombosis. The media was visibly thickened in several areas and seemed to separate almost spontaneously from the adventitia. A localized endarterectomy was performed and hyperplastic media and intimal flaps were removed. Several tacking sutures were applied to the distal, apparently normal, intimal edge to prevent further anterograde dissection. The arteriotomy was closed and excellent distal arterial pulsations were restored. Intraoperative arteriography revealed no residual occlusion and good intracranial circulation. Postoperatively the patient's neurological status slowly
432 0090-3019/81/120432-06501.25 © 1981 by Little, Brown and Company (Inc.)
Young et al: Fibromuscular Dysplasia
Fig, 1. Contrast-enhanced CT scans obtained upon admission showing several distinct round areas of decreased density in the left temporal and parietal lobes without mass effect (arrows).
433
434 SurgicalNeurology Vol 16 No 6 December 1981
A
C
Fig. 2. Left carotid angmgram obtained shortly after admission. ( A) Subtotal occlusion of the left internal carotid artery at the level of the atlas with dramatically decreased left middle cerebral artery. flow. (B) Total occlusion of left A , segment of anterior cerebral artery (embolic). ( C) Classic "string of beads" pattern pathognomonic of fibromuscular dysplasia in midportion of left internal carotid artery.
improved. By ten days after the operation, she could answer questions coherently and move her right arm almost normally. Repeat angiography revealed good flow past the area of previous occlusion and excellent filling of the left middle and anterior cerebral arteries. However, subtraction films of the left cervical carotid artery revealed areas of tight stenosis alternating with aneurysma[ dilatations that were pathognomonic of severe fibromuscular dysplasia (Fig. 3). The patient's neurological status continued to improve
slowly. Four weeks after the original operation, her only neurological deficit was a mild nominal dysphasia. At this point the patient was returned to the operating room and a saphenous vein autogenous jump graft was performed from the left carotid bifurcation to the distal left cervical internal carotid artery. Postoperative arteriography revealed a patent reconstruction without stenosis and excellent filling of the intracranial circulation (Fig. 4). The patient did well after this procedure and was sent
Young et ah Fibromuscular Dysplasia 435
i~iil ~ ~~ i~:~
ii ~'~
~
P i
ii I
Fig. 3. Left carotid angiogram (subtractions) obtained ten days after initial operation showing no residual occlusion but several areas of tight stenosis alternating with areas of aneurysmal dilatation indicative of severe fibromuscular dysplasia.
Fig. 4. Postoperative left carotid an~ogram performed after completion of autogenous saphenous vein bypass graft. Good filling of bypass graft and internal carotid artery is evident.
home in a few days with the same mild dysphasia. When last seen about five months after the operation, she had resumed normal activities. Her only neurological defect was mild hoarseness, probably caused by injury to the vagus nerve.
of fibromuscular dysplasia have been discovered incidentally during angiography for reasons other than cerebral ischemia [2, 7]. Until recently, fibromuscular dysplasia has been considered an important arterial disease more because of its association with intracranial aneurysms [9, 20] than as a cause of cerebral ischemia. However, several recent reports show that fibromuscular dysplasia can be associated with significant neurological disease [10, 23, 25], including recurrent cerebral ischemia [5, 6]. The static and benign natural history of fibromuscular dysplasia is now suspect; several reports clearly demonstrate slow but definite progression of the disease [7, 12]. Furthermore, large series of patients with symptoms of cerebral ischemia incriminate fibromuscular dysplasia as one of the more common nonatherosclerotic causes of carotid
Discussion Fibromuscular dysplasia is a generalized arteriopathy affecting small to medium-sized vessels. For many years it was known primarily as a curable cause of systemic hypertension resulting from involvement of the renal arteries [21]. In 1965, fibromuscular dysplasia was first described in the carotid artery, and a causal relationship between fibromuscular dysplasia and cerebral ischemic episodes was initially suggested [4]. However, the vast majority of reported cases
436
Surgical Neurology Vol 16 No 6 December 1981
stenosis [14]. Thus fibromuscular dysplasia is assuming an injury. Fibromuscular dysplasia-diseased intraabdominal increasingly important role in cerebrovascular disease. vessels seem susceptible to spontaneous dissection and Fibromuscular dysplasia is easily identified on radiog- (traumatic) occlusion [22]. A recent report by Ringel and raphy by multiple arterial dilatations alternating with ir- associates [24] describes a skier who suffered supposedly regularly spaced concentric stenosis, the pathognomonic traumatic dissections of both carotid and both vertebral ar"string of beads" pattern [19]. This conforms to the gross teries, all afflicted with fibromuscular dysplasia. Our patient appearance of the disease process, i.e., medial thickening had severe fibromuscular dysplasia of the left internal causing multiple stenotic segments alternating with focal carotid artery and mild disease of the right internal carotid outpouchings secondary to aneurysmal dilatation [27]. artery. She suffered traumatic cervical carotid artery occluMicroscopically the thickened media usually is related to sion of the more seriously involved artery after a seemingly disorganized fibroplasia; the dilatations are caused by dis- trivial blunt head injury. Many other cases of acute occluruption of the elastic membranes [27]. sion in fibromuscular dysplasia-diseased arteries may have Almost without exception, fibromuscular dysplasia of the been related to unrecognized trivial arterial injury. Thus it carotid artery occurs in the distal cervical carotid artery ad- seems possible that repeated mild vascular injury may play a jacent to the uppermost cervical vertebrae [19]. This par- role not only in the pathogenesis of fibromuscular dysplasia ticular segment of the carotid artery is intimately related to but also in eventual arterial occlusion and stroke. the bony prominences of the upper two cervical vertebrae. The usual treatment of fibromuscular dysplasia involving Thus during normal extension and rotation of the head, the carotid artery is individualized. Graduated internal dithis segment of internal carotid artery is particularly prone latation [15], endarterectomy with patch graft [23], resecto stretching and shearing around the bony margins [3]. tion of the diseased segment with end-to-end anastomosis The pathogenesis of fibromuscular dysplasia may be related [5], and autogenous venous jump grafts [4] have all been to this repeated traction on the carotid artery, predisposing used successfully. After traumatic cervical carotid artery octo disruption of the vasa vasorum [16, 27] and medial clusion with embolic symptoms but good collateral circulafibroplasia [27]. tion, anticoagulation and carotid occlusion may be conTraumatic cervical carotid artery occlusion in the ab- sidered. In the absence of good collateral circulation, sence of direct injury or previous disease is also generally thrombectomy with endarterectomy [14], resection, or confined to this same segment of artery. During even mild bypass graft seems warranted [26]. Other revascularization blunt injuries to the head with resultant sudden hyperten- procedures, including superficial temporal-middle cerebral sion or rotation of the neck, or both, this portion of the artery anastomoses, may be necessary in certain instances carotid artery is forcibly strained around the atlantoaxial [1]. bony prominences [13]. The delicate arterial intima can thereby be disrupted, causing intimal flap formation, medial dissection, and finally thrombosis [17]. Symptomatic References 1. Aarabi B, McQueen JD: Traumatic internal carotid occlusion at the traumatic cervical carotid artery occlusion in previously base of the skull. Surg Neurol 10:233-236, 1978 healthy arteries is certainly rare [11], although some degree 2. Anderson PE: Fibromuscularhyperplasiaof the carotid arteries. Acta of intimal injury may often occur after even minor Radiol [Diagn] (Stockh) 10:90-96, 1970 3. Boldrey E, Maass L, Miller ER: Role of atlantoid compression in craniocerebral trauma [18]. However, unless thrombosis etiology of internal carotid artery thrombosis. J Neurosurg 13:127with cerebral emboli or complete occlusion with inadequate 139, 1956 collateral circulation occurs, the patient may well be 4. Connett MC, LanscheJM: FibromuscularhyperplasiaOfthe internal carotid artery. Ann Surg 162:59-62, 1965 asymptomatic [8, 18]. 5. Ehrenfeld WK, Stoney RJ, Wylie EJ: Fibromuscular hyperplasiaof Symptomatic traumatic cervical carotid artery occlusion internal carotid artery. Arch Surg 95:284-287, 1967 in the atlantoaxial portion of the artery should occur more 6. Ehrenfeld WK, Wylie EJ: Fibromuscular dysplasia of the internal carotid artery. Arch Surg 109:676-681, 1974 frequently in arteries with preexisting disease. Traumatic 7. GalligioniF, lraci G, Marin G: Fibromuscularhyperplasiaof the excervical carotid artery occlusion at the bifurcation is seen tracranial internal carotid artery. J Neurosurg 34:647-651, 1971 often in association with preexisting atherosclerotic disease 8. GurdjianES, HardyWG, Lindner DW, ThomasLM: Closedcervical cranial trauma associated with involvementof carotid and vertebral [28]. Similarly, diseased segments of artery adjacent to arteries. J Neurosurg 20:418-427, 1963 bony protuberances seem more susceptible to even trivial 9. HandaJ, KamijyoY, Handa H: lntracranial aneurysmassociatedwith stretching and tearing of the intima or plaque, medial disfibromuscular-hyperplasiaof renal and internal carotid arteries. Br J Radiol 43:483-485, 1970 section, and thrombosis [ 17]. Thus patients with upper cer10. Hartman JD, Young 1, Bank AA, Rosenblott SA: Fibromuscular vical carotid artery atherosclerosis may be more vulnerable hyperplasia of internal carotid arteries: stroke in a young adult comto injury to the vessel and occlusion after trivial blunt head plicated by oral contraceptives. Arch Neurol 25:295-301, 1971 11. Higazi1: Post-traumaticcarotid thrombosis. J Neurosurg 20:354-359, injury. 1963 Along these lines, fibromuscular dysplasia of the atlanto- 12. Kincaid OW, Davis GD, Hallermann FJ, Hunt JC: Fibromuscular dysplasia of renal arteries. Am J Roentgenol 104:271-282, 1968 axial carotid artery may predispose this segment of vessel to
Young et al: Fibromuscular Dysplasia 437
13. Little JM, Vanderfield GK, May J, Lamont S: Traumatic thrombosis of internal carotid artery. Lancet 2:926-930, 1969 14. MomoseKJ, New PF: Non-atheromatous stenosis and occlusion of the internal carotid artery and its main branches. Am J Roentgenol 118:550-566, 1973 15. Morris GC, Lechter A, DeBakeyME: Surgical treatment of fibromuscular diseases of the carotid arteries. Arch Surg 96:636-643, 1967 16. Nakata Y: An experimental study on the vascular lesions caused by obstruction of the vasa vasorum. Jpn Circ J 31:275-287, 1967 17. New PF, Momose KJ: Traumatic dissection of the internal carotid artery at the atlantoaxial level secondary to non-penetrating injury. Radiology 93:41-49, 1969 18. Olafson RA, Christoferson LE: The syndrome of carotid occlusion following minor craniocerebral trauma. J Neurosurg 33:636-639, 1970 19. Osburn AG, Anderson RE: Angiographic spectrum of cervical and intracranial fibromusculardysplasia. Stroke 8:617-626, 1977 20. Palubinskas AJ, Perloff D, Newton TH: Fibromuscular hyperplasia--an arterial dysplasia of increasing clinical importance. Am J Roentgenol 98:907-913, 1966
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Editorial: Greatness Is Not Geographic For many, many years New England has flourished as the outstanding educational center of the United States. This element of greatness has extended from its private secondary schools, through its liberal arts colleges, and into its medical schools (at least some of them). This measure of greatness has persisted, although at all levels the difference between New England institutions and those in the rest of the country has lessened as institutions elsewhere have improved. T h e outstanding quality of New England institutions has been misinterpreted by some to mean that the young people of New England are also superior to others. This biased view has completely ignored the fact that New England's institutions of higher learning have maintained their position by recruiting their faculties and student bodies from the entire country and abroad. If we look for the m o m e n t at our own specialty--neurological surgery--we see that this is true. Cushing, although Professor at Harvard, came from Ohio; Dandy, Professor at Johns Hopkins, came from Missouri. More recently, William Sweet came from the state of Washington. These are but a few of the many examples illustrating the point that I wish to make. It would be obvious that those medical schools that recruit their faculties and student bodies from the widest possible area are the most outstanding. My personal experience may serve as an example. I attended the University of Iowa. I would have preferred going to Harvard, which had accepted my application, but I could not financially afford to do so. Iowa at that time was a distinctly mediocre institution. It had a few outstanding men on its faculty but most of the faculty were not known outside of that university. Its
student body was recruited largely from the state of Iowa. It was not alone in this position of mediocrity. This lower rung on the ladder of medical education was shared by many other medical schools. It was apparent to everyone that the first rung was occupied by the private schools such as Harvard, Johns Hopkins, and the University of Chicago, which were and which have remained truly national institutions. A l t h o u g h many of the state universities and their medical schools have made great progress in the last half century, others have not. A l l too many of them still restrict their student bodies largely to residents of that particular state. N o institution can restrict its selection of students to any limited group without suffering the consequences. These are all most damaging. We recognize that various states make this restriction on admission to their medical schools on the basis that the state supports the schools and that the benefits which derive from education there should be restricted to the citizens of the state. Such reasoning ignores the fact that many of the doctors who practice within the state, including the members of the faculty of the medical school, have been educated at medical schools that are located outside of the state. This is beneficial to the state and its citizens and is as it should be. States that place a restriction upon entrance to their medical schools must recognize that they are injuring only themselves. They are insuring that their medical school will be inferior. Paul C. Bucy, M . D . , Editor