Persistent Proatlantal Artery Associated with Carotid Artery Stenosis Treatment by Percutaneous Transluminal Balloon Angioplasty Pascal Bour, MD, Serge Bracard, MD, Nicolas Frisch, Robert Frisch, MD, Gdrard Fidv6, MD, Nancy, France
MD,
A 58-year-old man had an asymptomatic tight stenosis of the internal carotid artery associated with a persistent proatlantal artery. This as well as other compositional arterial anomalies of the basiiar artery were discovered on arteriograms. The stenosis was successfully treated by percutaneous transluminal balloon angioplasty. Therapeutic choices are discussed in this setting because of the risk of carotid clamping in the presence of persistent carotid-basilar anastomoses. (Ann Vasc Surg 1991 ;5:38-40). KEY WORDS:
Carotid artery; proatlantal artery; transluminal angioplasty.
As a persistent embryonic vessel, the proatlantal artery is a rare abnormal pathway between the carotid and vertebral arteries. Two types of proatlantal a r t e r y have been described according to whether it arises from the internal or external carotid artery [1]. This abnormal artery is always associated with the absence of the ipsilateral vertebral artery and hypoplasia or absence of the contralateral vertebral artery and on occasion with the posterior communicating artery [2]. In this setting, clamping of the carotid artery to treat carotid artery stenosis may be a problem. We report the case of a patient with carotid artery stenosis associated with ipsilateral proatlantal artery treated by percutaneous transluminal balloon angioplasty.
CASE REPORT A 58-year-old man was hospitalized for an asymptomatic right carotid bruit in November, 1987. Arteriograms of the neck vessels showed a tight stenosis located at the origin of the right internal carotid artery (Fig. 1). The right vertebral artery was absent. A proatlantal artery was seen to arise from the internal carotid artery less than one centimeter distal to the stenosis, at the level of C3. This artery joined the basilar artery by coursing through the foramen magnum. The left carotid vessels were normal. The left vertebral artery was hypoplastic and contributed little to the formation of the basilar trunk. Analysis of Willis' anastomotic circle revealed that the right posterior communicating artery was absent; the left posterior communicating artery was poorly injected. The anterior communicating artery was normal. Cranioencephalic computerized tomography (CT) was normal and confirmed that the proatlantal artery coursed through the foramen magnum. The hypoglossal canal was not enlarged. The stenosis was treated by percutaneous transluminal balloon angioplasty through the femoral artery with continuous electric syringe pump injected intravenous heparin. Two sessions of three short duration (less than 30 seconds) dilatations were performed at a six-month intervals. Adequate dilatation was achieved with a 4 x 7 mm, and then a 10 • 40 mm balloon, inflated between 4 and 5
From the Service de Chirurgie GOndrale et Vasculaire, HOpital Central and Service de Neuro-Radiologie, H6pital Saint Julien, Centre Hospitalier Rdgional et Universitaire, Nancy, France. Presented at the Annual Meeting of the Soci(t~ de Chirurgie Vasculaire de Langue Franqaise, May 18-19, 1990, Nancy, France. Reprint requests: R. Frisch, MD, Service de Chirurgie GdnOrale et Vasculaire, HOpital Central, 54037 Nancy, France. 38
VOLUME 5 N o 1 - 1991
S
39
P R O A T L A N T A L ARTER Y WITIt CAROTID STENOSIS
: :::::
i
:::;: :.
::i
Fig. 1. (a) Neck vessel arteriogram showing stenosis at origin of right internal carotid artery and proatlantal artery which arises from internal carotid distal to stenosis. (b) Diagram of lesions.
% ~!i:: i
atmospheres (Fig. 2). Aspirin was prescribed for two months following angioplasty. The postoperative outcome was uneventful and follow-up arteriograms showed that results were anatomically satisfactory in spite of a small posterior ectasia. Results were stable on arteriograms at six months.
DISCUSSION The first anatomic description of a proatlantal artery was made by Gottschau in 1885 [3]. In this case the patient's proatlantal artery arose from the internal carotid artery. Ouriel and associates reported the first case of proatlantal artery associated with carotid artery stenosis with surgical cure [4]. A p p r o x i m a t e l y 20 cases of proatlantal arteries have been described in the literature [5]. The e m b r y o n i c proatlantal artery is an important link in the formation of the vertebral arteries [6]. in the 4-5 m m e m b r y o , the proatlantal intersegmental artery, which arises from the carotid ductus, constitutes the caudal portion of the longitudinal neural artery. The role of this artery rapidly becomes predominant. At the 7-12 m m stage the artery starts to regress and at 12-14 ram, it is no longer identifiable. At this stage, the vertebral arteries are formed. The role of the proatlantal artery in the formation of the vertebral arteries appears to be p a r a m o u n t because the vertebral artery is generally absent when this embryonic artery persists. Arteriography d e m o n s t r a t e s the persistent proat-
'|
[L::;
:F
~:
Fig. 2. Arteriogram after percutaneous transluminal balloon angioplasty of carotid stenosis showing incomplete dilation after initial session.
lantal intersegmental artery, it arises from either the internal or external carotid artery, at the level of the 2nd or 3nd cervical vertebral bodies. The artery continues cephalad and posteriorly up to the lateral masses of the atlas without passing through the foramen transversarium. The terminal portion of its course is superimposable upon that of the vertebral
40
PROATLANTAL A R T E R Y WITH CAROTID STENOSIS
artery in the suboccipital area. The artery then passes through the occipital foramen magnum and joins the basilar artery. A persistent proatlantal intersegmental artery must be differentiated from two other anomalous carotid-basilar communications: the hypoglossal artery and the cervical intersegmental arteries. The hypoglossal artery generally arises higher in the cervical portion of the internal carotid artery through the hypoglossal canal at the base of the skull. The hypoglossal canal is enlarged on CT [7]. Certain carotid-basilar anastomoses, published as proatlantal arteries, are in fact anomalous persistence of the second cervical intersegmental artery because they unite with the vertebral artery at the level of t h e foramina in the transverse processes of C1 or C2 [8]. When carotid stenosis is associated with persistent proatlantal artery, carotid clamping can become a therapeutic dilemma [4,9]. This is due to the fact that the proatlantal artery is always associated with the absence of the ipsilateral vertebral artery and the absence or hypoplasia of the contralateral vertebral artery. Anomalous posterior communicating arteries are equally frequently encountered. Anomalous feeding arteries of the basilary artery account for the high incidence of posterior cerebral hypopeffusion in subjects with persistent carotid basilar anastomosis [4]. Only two cases of proatlantal arteries associated with carotid artery stenosis have been published [4,5]. Treatment consists of endarterectomy with carotid-proatlantal shunt protection because of the risk of posterior cerebral ischemia. The use of vein grafts has been proposed in the treatment of atheromatous stenosis of the carotidhypoglossal trunk to in order to reduce the risks of clamping [7]. in our case, we opted for a percutaneous transluminal balloon angioplasty because the
mum
ANNALS OF
VASCULARSURGERY
plaque was regular and we therefore did not need to insert a shunt under difficult conditions. Even though the clinical and roentgenologic outcomes were favorable, angioplasty remains an alternate method of treating atheromatous stenosis of the carotid because of the risk of cerebral embolism [I01. REFERENCES 1. LIE TA. Congenital anomalies of the carotid arteries. Amsterdam, Excerpta Medica 1968; pp 83-91. 2. TSUKAMOTO S, HOR1 Y, UTSUMI S, et al. Proatlantal intersegmental artery with absence of bilateral vertebral arteries. J Neurosurg 1981:54:122-124. 3. GOTTSCHAU M. Zwei seltene varietfiten der stamme des aortenbogens. Arch Anat Entwickl Gesch 1885;245-252. 4. OURIEL K, GREEN RM. DEWEESE JA. Anomalous carotid-basilar anastomoses in cerebrovascular surgery. J Vase Surg 1988;7:774-777. 5. TANAKA H, TAKAHASHI H, ISH1J1MA B, et al. A case of transient cerebral ischemia of the vertebro basilar system caused by carotid ulcerative lesion and persistent proatlantal intersegmental artery. No Shinkei Geka 1987;15:341-347. 6. PADGET DH. The development of the cranial arteries in the human embryo. Contr Embryo/ Carneg lnst 1948;32:205261. 7. CORMIER JM, RICtfE MC, CORM1ER F. Persistent carotido-hypoglossal artery associated with atherosclerotic stenosis treated by venous bypass. Ann Vasc Surg 1986;1: 258-263. 8. ANDERSON RA, SONDHEIMER FV. Rare carotid-vertebrobasilar anastomoses with notes on the differentiation between proatlantal and hypoglossal arteries. Neuroradiolo~y 1976:11:113-118. 9. OBAYASHI T, FURUSE M. The proatlantal intersegmental artery: a case report and review of the literature. Arch Neurol 1980:37:387-389. 10. MATHIAS K. Percutaneous transluminal angioplasty of the supra-aortiC arteries. In: DONDELINGER RF, ROSSI P, KURDZI EL JC, WALLACE S (eds). lnterventional Radiology. New York, Georg Thieme Verlag 1990; pp 564-583.
MD,
A 58-year-old man had an asymptomatic tight stenosis of the internal carotid artery associated with a persistent proatlantal artery. This as well as other compositional arterial anomalies of the basiiar artery were discovered on arteriograms. The stenosis was successfully treated by percutaneous transluminal balloon angioplasty. Therapeutic choices are discussed in this setting because of the risk of carotid clamping in the presence of persistent carotid-basilar anastomoses. (Ann Vasc Surg 1991 ;5:38-40). KEY WORDS:
Carotid artery; proatlantal artery; transluminal angioplasty.
As a persistent embryonic vessel, the proatlantal artery is a rare abnormal pathway between the carotid and vertebral arteries. Two types of proatlantal a r t e r y have been described according to whether it arises from the internal or external carotid artery [1]. This abnormal artery is always associated with the absence of the ipsilateral vertebral artery and hypoplasia or absence of the contralateral vertebral artery and on occasion with the posterior communicating artery [2]. In this setting, clamping of the carotid artery to treat carotid artery stenosis may be a problem. We report the case of a patient with carotid artery stenosis associated with ipsilateral proatlantal artery treated by percutaneous transluminal balloon angioplasty.
CASE REPORT A 58-year-old man was hospitalized for an asymptomatic right carotid bruit in November, 1987. Arteriograms of the neck vessels showed a tight stenosis located at the origin of the right internal carotid artery (Fig. 1). The right vertebral artery was absent. A proatlantal artery was seen to arise from the internal carotid artery less than one centimeter distal to the stenosis, at the level of C3. This artery joined the basilar artery by coursing through the foramen magnum. The left carotid vessels were normal. The left vertebral artery was hypoplastic and contributed little to the formation of the basilar trunk. Analysis of Willis' anastomotic circle revealed that the right posterior communicating artery was absent; the left posterior communicating artery was poorly injected. The anterior communicating artery was normal. Cranioencephalic computerized tomography (CT) was normal and confirmed that the proatlantal artery coursed through the foramen magnum. The hypoglossal canal was not enlarged. The stenosis was treated by percutaneous transluminal balloon angioplasty through the femoral artery with continuous electric syringe pump injected intravenous heparin. Two sessions of three short duration (less than 30 seconds) dilatations were performed at a six-month intervals. Adequate dilatation was achieved with a 4 x 7 mm, and then a 10 • 40 mm balloon, inflated between 4 and 5
From the Service de Chirurgie GOndrale et Vasculaire, HOpital Central and Service de Neuro-Radiologie, H6pital Saint Julien, Centre Hospitalier Rdgional et Universitaire, Nancy, France. Presented at the Annual Meeting of the Soci(t~ de Chirurgie Vasculaire de Langue Franqaise, May 18-19, 1990, Nancy, France. Reprint requests: R. Frisch, MD, Service de Chirurgie GdnOrale et Vasculaire, HOpital Central, 54037 Nancy, France. 38
VOLUME 5 N o 1 - 1991
S
39
P R O A T L A N T A L ARTER Y WITIt CAROTID STENOSIS
: :::::
i
:::;: :.
::i
Fig. 1. (a) Neck vessel arteriogram showing stenosis at origin of right internal carotid artery and proatlantal artery which arises from internal carotid distal to stenosis. (b) Diagram of lesions.
% ~!i:: i
atmospheres (Fig. 2). Aspirin was prescribed for two months following angioplasty. The postoperative outcome was uneventful and follow-up arteriograms showed that results were anatomically satisfactory in spite of a small posterior ectasia. Results were stable on arteriograms at six months.
DISCUSSION The first anatomic description of a proatlantal artery was made by Gottschau in 1885 [3]. In this case the patient's proatlantal artery arose from the internal carotid artery. Ouriel and associates reported the first case of proatlantal artery associated with carotid artery stenosis with surgical cure [4]. A p p r o x i m a t e l y 20 cases of proatlantal arteries have been described in the literature [5]. The e m b r y o n i c proatlantal artery is an important link in the formation of the vertebral arteries [6]. in the 4-5 m m e m b r y o , the proatlantal intersegmental artery, which arises from the carotid ductus, constitutes the caudal portion of the longitudinal neural artery. The role of this artery rapidly becomes predominant. At the 7-12 m m stage the artery starts to regress and at 12-14 ram, it is no longer identifiable. At this stage, the vertebral arteries are formed. The role of the proatlantal artery in the formation of the vertebral arteries appears to be p a r a m o u n t because the vertebral artery is generally absent when this embryonic artery persists. Arteriography d e m o n s t r a t e s the persistent proat-
'|
[L::;
:F
~:
Fig. 2. Arteriogram after percutaneous transluminal balloon angioplasty of carotid stenosis showing incomplete dilation after initial session.
lantal intersegmental artery, it arises from either the internal or external carotid artery, at the level of the 2nd or 3nd cervical vertebral bodies. The artery continues cephalad and posteriorly up to the lateral masses of the atlas without passing through the foramen transversarium. The terminal portion of its course is superimposable upon that of the vertebral
40
PROATLANTAL A R T E R Y WITH CAROTID STENOSIS
artery in the suboccipital area. The artery then passes through the occipital foramen magnum and joins the basilar artery. A persistent proatlantal intersegmental artery must be differentiated from two other anomalous carotid-basilar communications: the hypoglossal artery and the cervical intersegmental arteries. The hypoglossal artery generally arises higher in the cervical portion of the internal carotid artery through the hypoglossal canal at the base of the skull. The hypoglossal canal is enlarged on CT [7]. Certain carotid-basilar anastomoses, published as proatlantal arteries, are in fact anomalous persistence of the second cervical intersegmental artery because they unite with the vertebral artery at the level of t h e foramina in the transverse processes of C1 or C2 [8]. When carotid stenosis is associated with persistent proatlantal artery, carotid clamping can become a therapeutic dilemma [4,9]. This is due to the fact that the proatlantal artery is always associated with the absence of the ipsilateral vertebral artery and the absence or hypoplasia of the contralateral vertebral artery. Anomalous posterior communicating arteries are equally frequently encountered. Anomalous feeding arteries of the basilary artery account for the high incidence of posterior cerebral hypopeffusion in subjects with persistent carotid basilar anastomosis [4]. Only two cases of proatlantal arteries associated with carotid artery stenosis have been published [4,5]. Treatment consists of endarterectomy with carotid-proatlantal shunt protection because of the risk of posterior cerebral ischemia. The use of vein grafts has been proposed in the treatment of atheromatous stenosis of the carotidhypoglossal trunk to in order to reduce the risks of clamping [7]. in our case, we opted for a percutaneous transluminal balloon angioplasty because the
mum
ANNALS OF
VASCULARSURGERY
plaque was regular and we therefore did not need to insert a shunt under difficult conditions. Even though the clinical and roentgenologic outcomes were favorable, angioplasty remains an alternate method of treating atheromatous stenosis of the carotid because of the risk of cerebral embolism [I01. REFERENCES 1. LIE TA. Congenital anomalies of the carotid arteries. Amsterdam, Excerpta Medica 1968; pp 83-91. 2. TSUKAMOTO S, HOR1 Y, UTSUMI S, et al. Proatlantal intersegmental artery with absence of bilateral vertebral arteries. J Neurosurg 1981:54:122-124. 3. GOTTSCHAU M. Zwei seltene varietfiten der stamme des aortenbogens. Arch Anat Entwickl Gesch 1885;245-252. 4. OURIEL K, GREEN RM. DEWEESE JA. Anomalous carotid-basilar anastomoses in cerebrovascular surgery. J Vase Surg 1988;7:774-777. 5. TANAKA H, TAKAHASHI H, ISH1J1MA B, et al. A case of transient cerebral ischemia of the vertebro basilar system caused by carotid ulcerative lesion and persistent proatlantal intersegmental artery. No Shinkei Geka 1987;15:341-347. 6. PADGET DH. The development of the cranial arteries in the human embryo. Contr Embryo/ Carneg lnst 1948;32:205261. 7. CORMIER JM, RICtfE MC, CORM1ER F. Persistent carotido-hypoglossal artery associated with atherosclerotic stenosis treated by venous bypass. Ann Vasc Surg 1986;1: 258-263. 8. ANDERSON RA, SONDHEIMER FV. Rare carotid-vertebrobasilar anastomoses with notes on the differentiation between proatlantal and hypoglossal arteries. Neuroradiolo~y 1976:11:113-118. 9. OBAYASHI T, FURUSE M. The proatlantal intersegmental artery: a case report and review of the literature. Arch Neurol 1980:37:387-389. 10. MATHIAS K. Percutaneous transluminal angioplasty of the supra-aortiC arteries. In: DONDELINGER RF, ROSSI P, KURDZI EL JC, WALLACE S (eds). lnterventional Radiology. New York, Georg Thieme Verlag 1990; pp 564-583.
