142
Surg Neurol 1992;37:142-6
Mycotic Aneurysms of the Intracavernous Carotid Artery: A Case Report and Review of the Literature Robert W. Hurst, M.D., I.S. Choi, M.D., Mark Persky, M.D., and Mark Kupersmith, M.D. Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania; Departments of Radiology, Otolaryngology, and Neurology and Ophthalmology, New York Medical Center, New York, New York
Hurst RW, Choi IS, Persky M, Kupersmith M. Mycotic aneurysms of the intracavernous carotid artery: a case report and review of the literature. Surg Neurol 1992;37:142-6.
A case of mycotic aneurysm of the intracavernous carotid artery is reported and the literature is reviewed on this uncommon entity. Nineteen cases have been reported, most often occurring in the clinical setting of meningitis. Management recommendations include angiographic confirmation of aneurysm and follow-up with magnetic resonance imaging during antibiotic therapy. Evidence of aneurysm enlargement is an indication for endovascular trapping of the aneurysm or carotid occlusion. KEY WORDS: Aneurysm; Cavernous carotid; Mycotic; Endovascular therapy
The intracavernous internal carotid artery (ICA) is that portion of the extradural ICA that is most commonly affected by aneurysms. Aneurysms of this segment of the carotid artery constitute approximately 5% of all intracranial aneurysms. Congenital or developmental aneurysms most often affect the intracavernous carotid followed in frequency by those of traumatic origin [ 10]. Mycotic aneurysms of the intracavernous ICA are distinctly rare, only 19 cases being reported in the English literature. We report an additional case of mycotic aneurysm of the intracavernous carotid artery that was successfully treated by endovascular means. Case Report A 45-year-old man had previously been in good health until January 1990, when he developed generalized headache and right eye pain. An unenhanced computed tomography (CT) scan revealed pansinusitis including involvement of the sphenoid sinus (Figure 1 A and B). Address reprint requests to: Robert W. Hurst, M.D., Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, Pennsylvania 19104. Received June 20, 1991; accepted September 18, 1991.
(© 1992 by R.W. Hurst et al.
A history of previous severe contrast reaction precluded the use of enhanced CT. Bony erosion was present that involved the superolateral wall of the right sphenoid sinus, which was suggestive of osteomyelitis. Magnetic resonance imaging (MRI) demonstrated homogeneous soft tissue intensity throughout the sinuses but no evidence of hemorrhage or flow void. The patient was admitted to an outside institution, where surgical drainage of the ethmoids and irrigation of the sphenoid sinus was performed with removal of considerable pus. N o significant bleeding was noted at operation. Cultures grew Gram-negative and anaerobic organisms. Continued elevation of WBC and ESR after 10 days of intravenous ampicillin and sulbactam (Unasyn R: 2 g every 6 hours) was noted. A presumed diagnosis ofosteomyelitis was made and a 6-week course of intravenous antibiotics was initiated. Blood cultures on several occasions were negative. The patient noted new-onset right visual blurring 5½ weeks into the antibiotic treatment. MRI was repeated and was remarkable for abnormal heterogeneous signal intensity involving the sphenoid sinus on all imaging sequences (Figure 2 A and B). Homogeneous enhancement was present within the sphenoid sinus on postenhanced images, N o evidence of cavernous sinus thrombosis was present. Differential considerations included abscess versus aneurysm. Visual acuity of the right eye at that time was noted to have deteriorated to 20/200. N o other neurological abnormalities were present. The patient was transferred to New York University Medical Center. Following steroid pretreatment, angiography was performed with nonionic contrast material. Angiography revealed a large irregular aneurysm of the intracavernous portion of the right ICA with extension into the sphenoid sinus (Figure 3 A and B). The carotid artery was irregular in caliber distal to the level of the origin of the ophthalmic artery. Occlusion of the right ICA was performed with a # 1 6 Debrun detachable latex balloon (Ingenor; Paris). Following a 20-minute occlusion test without the development of neurological symptoms, the balloon was de-
Mycotic Aneurysms of Intracavernous Carotid
Surg Neurol 1992;37:142-6
143
The patient has done well for I year following carotid occlusion without recurrence of symptoms.
Discussion Mycotic aneurysms involving the intracavernous portion of the ICA were first reported after identification at autopsy by Barker in 1953 [2]. A total of 19 cases have been reported in the English literature, the features of Figure 2. (A) Axial unenhanced and (B) coronalenhanced Tl-weighted MRI after antibiotic therapy. Images show newly developed heterogeneous signal with enhancement within the sphenoid sinus.
Figure 1. (A) Axial and (B) coronal CT scans demonstrate homogeneous soft tissue density within the sphenoid sinus with irregular erosivechanges involving the superolateral wall of the sphenoid.
tached in the carotid artery just proximal to the aneurysm. Two additional balloons were then detached proximally in the right ICA to obtain complete occlusion of the ICA. Follow-up angiography demonstrated continued occlusion of the right ICA. No filling of the aneurysm was identified. Follow-up MRI 3 weeks after occlusion showed high signal throughout the area of previous aneurysm that was consistent with thrombus formation.
144
Surg Neurol 1992;37:142-6
Hurst et al
Table 1. BacterialAneurysms of the Cavernous Carotid Artery Case
Reference
Age/sex
Side
Clinical setting
32 M 1.5 M
BL L
6M
L
4
6F
R
5
10M
R
33M 30 M 7M
R R R
42 F
L
Meningitis; CST Orbital infection; hemiparesis Meningitis (staph); hemiparesis CST (staph); ophthalmoplegia Meningitis (staph); R ophthalmoplegia CST; decreasing vision Meningitis; ophthalmoplegia Meningitis (staph); ophthalmoplegia; aneurysm enlarging Meningitis (staph); ophthalmoplegia; aneurysm enlarged (over 10 days) Meningitis (staph); ophthalmoplegia; aneurysm enlarged (5 days) Meningitis (staph) ophthalmoplegia; aneurysm enlarged (6 days) Meningitis; ophthalmoplegia Meningitis Meningitis (staph); ophthalmoplegia Meningitis (staph); ophthalmoplegia Orbital abscess; improving ophthalmoplegia with aneurysm growth Meningitis; ophthalmoplegia, hemiparesis Meningitis; ophthalmoplegia; enlarging aneurysm on antibiotic medication Meningitis (staph); ophthalmoplegia, hemiparesis Sphenoid sinusitis; decreased vision
1 2
Barker [2] Devadiga et al [4]
3
Suwanwela et al [13]
6 7 8
9
Adeloye et al [1] Lansky and Maxwell (9) Shibuya et al [12]
l0
Johnson [8]
3M
BL
11
Tomita et al [14]
2 M
R
12 13 14
Eguchi et al [5] Rout et al [11]
22 M 2.5 F 5.5 M
BL L L
15
5F
L
16
18 F
R
17
32 F
R
18
59 M
R
19
Isaacs and van Dellen [7]
10 M
20
Present case
45 M
R
Rx
Outcome
Conservative Conservative
Death ICA Thrombosis
Conservative
ICA Thrombosis
Conservative
Aneurysm resolved
Conservative
Lost to follow-up
Ligation Conservative Carotid ligation
No clinical change Improved Improved
Carotid ligation
Improved
BL ICA ligation
Improved
ICA ligation
Aneurysm resolved
BL ICA ligation Antibiotics Carotid ligation
Improved Aneurysm resolved lmproved
Antibiotics
Thrombosis of ICA
Antibiotics (refused surgery)
Lost to follow-up
Antibiotics
Improved
Carotid ligation
Improved
Antibiotics
Improved
ICA balloon occlusion
Improved
Abbreviations: BL, bilateral; CST, cavernous sinus thrombosis; F, female; ICA, internal carotid artery; L, left; R, right; M, male.
which are tabulated in Table 1. T h e first case diagnosed p r e m o r t e m was noted in 1969 in an 18-month-old child following a severe orbital infection [4]. Follow-up anglogram after 2 years of conservative therapy documented resolution of the aneurysm. Surgical treatment for mycotic intracavernous aneurysm was not reported until 1972, when Suwanwela et al [ 13] reported successful treatment by carotid ligation in an adult. Carotid ligation was p e r f o r m e d in five cases during the period from 1975 through 1982.
Indications included aneurysmal enlargement or symptom progression during therapy with antibiotics [5,8,9,12,14]. Rapidity was the hallmark in several of these cases, with significant aneurysmal enlargement occurring over 5 - 1 0 days [8,12,14]. All cases however, had good outcomes following carotid ligation. The largest series, six cases, was reported in 1984 by Rout et al [11]. Initial therapy with antibiotics was started in all cases. T h r e e cases showed enlargement of the aneurysm or s y m p t o m progression, and two of these
Mycotic Aneurysms of Intracavernous Carotid
Figure 3. (A) Lateral and (B) anteroposterior left internal carotid artery angiography reveals a large aneurysm filling the sphenoid sinus. were treated with carotid ligation (the third refused surgical therapy). In one case, symptom improvement had occurred on antibiotic therapy despite the finding of aneurysmal enlargement on repeat angiography. In the remaining three cases, antibiotic therapy resulted in resolution of the aneurysm or symptoms in all cases. The present case involves a 45-year-old man with development of a mycotic aneurysm of the ICA following pansinusitis. Decreased visual acuity prompted angiographic examination in the face of apparently adequate
Surg Neurol 1992;37:142-6
145
antibiotic treatment. The relatively rapid development of this large symptomatic aneurysm over a 2-month period with extension into the sphenoid sinus and consequent risk of potentially fatal epistaxis made immediate treatment imperative. T h e r e are 14 males and 6 females in the reported series whose average age was 18.3 years. The youngest patient was 1.5 years of age while the oldest was 59 years. Eleven of the patients were 10 years old or younger. Nine of the patients required carotid ligation, while 11 were treated with antibiotics alone. Aneurysms occurred bilaterally in 15 %. Examination of the clinical features of these 20 reported cases reveals the presence of confirmed infection, with staphylococcus as the responsible organism in 10 cases. Fifteen of the cases had clinical features of meningitis, by far the most common clinical setting in which these aneurysms seem to occur. Two cases had documented infections of the orbit, while two more were described as having cavernous sinus thrombosis. The present case is the first to have developed cavernous aneurysm secondary to sphenoid sinusitis as well as the first to be treated by endovascular means. The close proximity of the intracavernous carotid to the sphenoid sinus provides contiguity for the direct involvement of the carotid by infectious processes originating in the sphenoid. Involvement of the carotid may be even more likely in the 8% of patients who have no bony wall between the ICA and the sinus [6]. The potential for sphenoid sinusitis to affect the carotid artery has been demonstrated by the report of Whitehead and DeSouza [15] of severe carotid artery spasm due to acute sphenoid sinusitis. Most cavernous mycotic aneurysms arise from direct extension of infection to the artery. This represents a relatively uncommon means of development of mycotic aneurysms, which are most often a result of embolization, commonly from bacterial endocarditis. Nevertheless, like all mycotic aneurysms, the clinical progression is often unpredictable, as evidenced by the reports of enlargement over periods of 10 days or less as well as aneurysmal enlargement in the face of clinical improvement [3]. Clinical unpredictability makes formulation of management protocols difficult. Rout et al [ 11] recommended initial antibiotic therapy for intracavernous mycotic aneurysms with follow-up angiography in 4 - 6 weeks. If ophthalmoplegia improved and the aneurysm remained static or became smaller during that period, antibiotic therapy was continued. Carotid ligation was recommended in cases where aneurysm enlargement occurred regardless of the clinical picture. We would revise these recommendations in light of several advances that have occurred since those of Rout. The present case demonstrates the usefulness of MRI in
146
Surg N e u r o l 1992;37:142-6
the detection of cavernous carotid aneurysms. Angiography remains indicated in suspicious cases to confirm both the presence and anatomical features of the aneurysm. MRI may then be useful to detect any aneurysmal enlargement and should be performed every 1-2 weeks throughout the course of antibiotic therapy. In the face of aneurysm enlargement or clinical deterioration despite antibiotic therapy, immediate endovascular aneurysm trapping or carotid occlusion is indicated. Sphenoid sinus extension, or hemispheric neurological deficits compatible with aneurysm-originated embolism, also indicate immediate carotid occlusion. Endovascular therapy is best performed following the longest feasible course of antibiotics to permit maximal healing of the arterial wall prior to balloon occlusion. Nevertheless, any of the above-noted features signaling a particularly dangerous situation are best dealt with by immediate occlusion.
Conclusion
H u r s t et al
2. Barker WF. Mycotic aneurysms. Ann Surg 1953;139:84-9. 3. BrustJCM, Dickinson PCT, Hughes JEO, Holtzman RNN. The diagnosis and treatment of cerebral mycotic aneurysms. Ann Neurol 1990;27:238-46. 4. Devadiga KV, Mathai KV, Chandy J. Case reports and technical notes: spontaneous cure of intracavernous aneurysm of the internal carotid artery in a 14-month-old child. J Neurosurg 1969;30:165-8. 5. Eguchi T, Nakagomi T, Teraoka A. Treatment of bilateral mycotic intracavernous carotid aneurysms. J Neurosurg 1982;56:443-7. 6. Fujii K, Chambers SM, Rhoton AFJr. Neurovascular relationships of the sphenoid sinus: a microsurgical study. J Neurosurg 1979;50:31-9. 7. Isaacs BA, van Dellen JR. Persistence of a mycotic aneurysm of the intracavernous carotid artery. Surg Neurol 1986;26:577-80. 8. Johnson I. Direct surgical treatment of bilateral intracavernous internal carotid artery aneurysms. J Neurosurg 1979;51:98-102. 9. Lansky LL, MaxwellJA. Mycotic aneurysm of the internal carotid artery in an unusual intra-cranial location. Dev Med. Child Neurol 1975;17:79-88. 10. Lasjaunias P, Berenstein A. Surgical neuroangiography. Vol 2: Endovascular treatment of craniofacial lesions, 235-71. 11. Rout D, McAnn PK, Rao VRK. Bacterial aneurysms of the intracavernous carotid artery, case report. J Neurosurg 1984;60:1236-42.
We have reported a case of bacterial aneurysm of the ICA and reviewed the literature regarding previous cases. The potentially useful role of MRI in both diagnosis and following of such cases was noted as was the usefulness of endovascular occlusion should antibiotic therapy fail to lead to aneurysm resolution.
13. Suwanwela C, Suwanwela N, Srisakul C, Hongsaprabhasc C. Intracranial mycotic aneurysms of extravascular origin. J Neurosurg 1972;36:552-9.
References
14. Tomita T, McLone DG, Naidich TP. Mycotic aneurysm of the intracavernous portion of the carotid artery in childhood. J Neurosurg 1981;54:681-4.
1. Adeloye A, Sigh SP, Osinowo O: Extravascular mycotic aneurysm of the intracavernous portion of the internal carotid artery. West African Med J 1973;22:44-66.
12. Shibuya S, Igarashi S, Amo T, Sato H, Fukumitsu T. Mycotic aneurysms of the internal carotid artery. J Neurosurg 1976;44:105-8.
15. Whitehead E, DeSouza FM. Acute sphenoid sinusitis causing spasm of the internal carotid artery. Can J Otolaryngol. 1974;32:216-8.
Surg Neurol 1992;37:142-6
Mycotic Aneurysms of the Intracavernous Carotid Artery: A Case Report and Review of the Literature Robert W. Hurst, M.D., I.S. Choi, M.D., Mark Persky, M.D., and Mark Kupersmith, M.D. Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania; Departments of Radiology, Otolaryngology, and Neurology and Ophthalmology, New York Medical Center, New York, New York
Hurst RW, Choi IS, Persky M, Kupersmith M. Mycotic aneurysms of the intracavernous carotid artery: a case report and review of the literature. Surg Neurol 1992;37:142-6.
A case of mycotic aneurysm of the intracavernous carotid artery is reported and the literature is reviewed on this uncommon entity. Nineteen cases have been reported, most often occurring in the clinical setting of meningitis. Management recommendations include angiographic confirmation of aneurysm and follow-up with magnetic resonance imaging during antibiotic therapy. Evidence of aneurysm enlargement is an indication for endovascular trapping of the aneurysm or carotid occlusion. KEY WORDS: Aneurysm; Cavernous carotid; Mycotic; Endovascular therapy
The intracavernous internal carotid artery (ICA) is that portion of the extradural ICA that is most commonly affected by aneurysms. Aneurysms of this segment of the carotid artery constitute approximately 5% of all intracranial aneurysms. Congenital or developmental aneurysms most often affect the intracavernous carotid followed in frequency by those of traumatic origin [ 10]. Mycotic aneurysms of the intracavernous ICA are distinctly rare, only 19 cases being reported in the English literature. We report an additional case of mycotic aneurysm of the intracavernous carotid artery that was successfully treated by endovascular means. Case Report A 45-year-old man had previously been in good health until January 1990, when he developed generalized headache and right eye pain. An unenhanced computed tomography (CT) scan revealed pansinusitis including involvement of the sphenoid sinus (Figure 1 A and B). Address reprint requests to: Robert W. Hurst, M.D., Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, Pennsylvania 19104. Received June 20, 1991; accepted September 18, 1991.
(© 1992 by R.W. Hurst et al.
A history of previous severe contrast reaction precluded the use of enhanced CT. Bony erosion was present that involved the superolateral wall of the right sphenoid sinus, which was suggestive of osteomyelitis. Magnetic resonance imaging (MRI) demonstrated homogeneous soft tissue intensity throughout the sinuses but no evidence of hemorrhage or flow void. The patient was admitted to an outside institution, where surgical drainage of the ethmoids and irrigation of the sphenoid sinus was performed with removal of considerable pus. N o significant bleeding was noted at operation. Cultures grew Gram-negative and anaerobic organisms. Continued elevation of WBC and ESR after 10 days of intravenous ampicillin and sulbactam (Unasyn R: 2 g every 6 hours) was noted. A presumed diagnosis ofosteomyelitis was made and a 6-week course of intravenous antibiotics was initiated. Blood cultures on several occasions were negative. The patient noted new-onset right visual blurring 5½ weeks into the antibiotic treatment. MRI was repeated and was remarkable for abnormal heterogeneous signal intensity involving the sphenoid sinus on all imaging sequences (Figure 2 A and B). Homogeneous enhancement was present within the sphenoid sinus on postenhanced images, N o evidence of cavernous sinus thrombosis was present. Differential considerations included abscess versus aneurysm. Visual acuity of the right eye at that time was noted to have deteriorated to 20/200. N o other neurological abnormalities were present. The patient was transferred to New York University Medical Center. Following steroid pretreatment, angiography was performed with nonionic contrast material. Angiography revealed a large irregular aneurysm of the intracavernous portion of the right ICA with extension into the sphenoid sinus (Figure 3 A and B). The carotid artery was irregular in caliber distal to the level of the origin of the ophthalmic artery. Occlusion of the right ICA was performed with a # 1 6 Debrun detachable latex balloon (Ingenor; Paris). Following a 20-minute occlusion test without the development of neurological symptoms, the balloon was de-
Mycotic Aneurysms of Intracavernous Carotid
Surg Neurol 1992;37:142-6
143
The patient has done well for I year following carotid occlusion without recurrence of symptoms.
Discussion Mycotic aneurysms involving the intracavernous portion of the ICA were first reported after identification at autopsy by Barker in 1953 [2]. A total of 19 cases have been reported in the English literature, the features of Figure 2. (A) Axial unenhanced and (B) coronalenhanced Tl-weighted MRI after antibiotic therapy. Images show newly developed heterogeneous signal with enhancement within the sphenoid sinus.
Figure 1. (A) Axial and (B) coronal CT scans demonstrate homogeneous soft tissue density within the sphenoid sinus with irregular erosivechanges involving the superolateral wall of the sphenoid.
tached in the carotid artery just proximal to the aneurysm. Two additional balloons were then detached proximally in the right ICA to obtain complete occlusion of the ICA. Follow-up angiography demonstrated continued occlusion of the right ICA. No filling of the aneurysm was identified. Follow-up MRI 3 weeks after occlusion showed high signal throughout the area of previous aneurysm that was consistent with thrombus formation.
144
Surg Neurol 1992;37:142-6
Hurst et al
Table 1. BacterialAneurysms of the Cavernous Carotid Artery Case
Reference
Age/sex
Side
Clinical setting
32 M 1.5 M
BL L
6M
L
4
6F
R
5
10M
R
33M 30 M 7M
R R R
42 F
L
Meningitis; CST Orbital infection; hemiparesis Meningitis (staph); hemiparesis CST (staph); ophthalmoplegia Meningitis (staph); R ophthalmoplegia CST; decreasing vision Meningitis; ophthalmoplegia Meningitis (staph); ophthalmoplegia; aneurysm enlarging Meningitis (staph); ophthalmoplegia; aneurysm enlarged (over 10 days) Meningitis (staph); ophthalmoplegia; aneurysm enlarged (5 days) Meningitis (staph) ophthalmoplegia; aneurysm enlarged (6 days) Meningitis; ophthalmoplegia Meningitis Meningitis (staph); ophthalmoplegia Meningitis (staph); ophthalmoplegia Orbital abscess; improving ophthalmoplegia with aneurysm growth Meningitis; ophthalmoplegia, hemiparesis Meningitis; ophthalmoplegia; enlarging aneurysm on antibiotic medication Meningitis (staph); ophthalmoplegia, hemiparesis Sphenoid sinusitis; decreased vision
1 2
Barker [2] Devadiga et al [4]
3
Suwanwela et al [13]
6 7 8
9
Adeloye et al [1] Lansky and Maxwell (9) Shibuya et al [12]
l0
Johnson [8]
3M
BL
11
Tomita et al [14]
2 M
R
12 13 14
Eguchi et al [5] Rout et al [11]
22 M 2.5 F 5.5 M
BL L L
15
5F
L
16
18 F
R
17
32 F
R
18
59 M
R
19
Isaacs and van Dellen [7]
10 M
20
Present case
45 M
R
Rx
Outcome
Conservative Conservative
Death ICA Thrombosis
Conservative
ICA Thrombosis
Conservative
Aneurysm resolved
Conservative
Lost to follow-up
Ligation Conservative Carotid ligation
No clinical change Improved Improved
Carotid ligation
Improved
BL ICA ligation
Improved
ICA ligation
Aneurysm resolved
BL ICA ligation Antibiotics Carotid ligation
Improved Aneurysm resolved lmproved
Antibiotics
Thrombosis of ICA
Antibiotics (refused surgery)
Lost to follow-up
Antibiotics
Improved
Carotid ligation
Improved
Antibiotics
Improved
ICA balloon occlusion
Improved
Abbreviations: BL, bilateral; CST, cavernous sinus thrombosis; F, female; ICA, internal carotid artery; L, left; R, right; M, male.
which are tabulated in Table 1. T h e first case diagnosed p r e m o r t e m was noted in 1969 in an 18-month-old child following a severe orbital infection [4]. Follow-up anglogram after 2 years of conservative therapy documented resolution of the aneurysm. Surgical treatment for mycotic intracavernous aneurysm was not reported until 1972, when Suwanwela et al [ 13] reported successful treatment by carotid ligation in an adult. Carotid ligation was p e r f o r m e d in five cases during the period from 1975 through 1982.
Indications included aneurysmal enlargement or symptom progression during therapy with antibiotics [5,8,9,12,14]. Rapidity was the hallmark in several of these cases, with significant aneurysmal enlargement occurring over 5 - 1 0 days [8,12,14]. All cases however, had good outcomes following carotid ligation. The largest series, six cases, was reported in 1984 by Rout et al [11]. Initial therapy with antibiotics was started in all cases. T h r e e cases showed enlargement of the aneurysm or s y m p t o m progression, and two of these
Mycotic Aneurysms of Intracavernous Carotid
Figure 3. (A) Lateral and (B) anteroposterior left internal carotid artery angiography reveals a large aneurysm filling the sphenoid sinus. were treated with carotid ligation (the third refused surgical therapy). In one case, symptom improvement had occurred on antibiotic therapy despite the finding of aneurysmal enlargement on repeat angiography. In the remaining three cases, antibiotic therapy resulted in resolution of the aneurysm or symptoms in all cases. The present case involves a 45-year-old man with development of a mycotic aneurysm of the ICA following pansinusitis. Decreased visual acuity prompted angiographic examination in the face of apparently adequate
Surg Neurol 1992;37:142-6
145
antibiotic treatment. The relatively rapid development of this large symptomatic aneurysm over a 2-month period with extension into the sphenoid sinus and consequent risk of potentially fatal epistaxis made immediate treatment imperative. T h e r e are 14 males and 6 females in the reported series whose average age was 18.3 years. The youngest patient was 1.5 years of age while the oldest was 59 years. Eleven of the patients were 10 years old or younger. Nine of the patients required carotid ligation, while 11 were treated with antibiotics alone. Aneurysms occurred bilaterally in 15 %. Examination of the clinical features of these 20 reported cases reveals the presence of confirmed infection, with staphylococcus as the responsible organism in 10 cases. Fifteen of the cases had clinical features of meningitis, by far the most common clinical setting in which these aneurysms seem to occur. Two cases had documented infections of the orbit, while two more were described as having cavernous sinus thrombosis. The present case is the first to have developed cavernous aneurysm secondary to sphenoid sinusitis as well as the first to be treated by endovascular means. The close proximity of the intracavernous carotid to the sphenoid sinus provides contiguity for the direct involvement of the carotid by infectious processes originating in the sphenoid. Involvement of the carotid may be even more likely in the 8% of patients who have no bony wall between the ICA and the sinus [6]. The potential for sphenoid sinusitis to affect the carotid artery has been demonstrated by the report of Whitehead and DeSouza [15] of severe carotid artery spasm due to acute sphenoid sinusitis. Most cavernous mycotic aneurysms arise from direct extension of infection to the artery. This represents a relatively uncommon means of development of mycotic aneurysms, which are most often a result of embolization, commonly from bacterial endocarditis. Nevertheless, like all mycotic aneurysms, the clinical progression is often unpredictable, as evidenced by the reports of enlargement over periods of 10 days or less as well as aneurysmal enlargement in the face of clinical improvement [3]. Clinical unpredictability makes formulation of management protocols difficult. Rout et al [ 11] recommended initial antibiotic therapy for intracavernous mycotic aneurysms with follow-up angiography in 4 - 6 weeks. If ophthalmoplegia improved and the aneurysm remained static or became smaller during that period, antibiotic therapy was continued. Carotid ligation was recommended in cases where aneurysm enlargement occurred regardless of the clinical picture. We would revise these recommendations in light of several advances that have occurred since those of Rout. The present case demonstrates the usefulness of MRI in
146
Surg N e u r o l 1992;37:142-6
the detection of cavernous carotid aneurysms. Angiography remains indicated in suspicious cases to confirm both the presence and anatomical features of the aneurysm. MRI may then be useful to detect any aneurysmal enlargement and should be performed every 1-2 weeks throughout the course of antibiotic therapy. In the face of aneurysm enlargement or clinical deterioration despite antibiotic therapy, immediate endovascular aneurysm trapping or carotid occlusion is indicated. Sphenoid sinus extension, or hemispheric neurological deficits compatible with aneurysm-originated embolism, also indicate immediate carotid occlusion. Endovascular therapy is best performed following the longest feasible course of antibiotics to permit maximal healing of the arterial wall prior to balloon occlusion. Nevertheless, any of the above-noted features signaling a particularly dangerous situation are best dealt with by immediate occlusion.
Conclusion
H u r s t et al
2. Barker WF. Mycotic aneurysms. Ann Surg 1953;139:84-9. 3. BrustJCM, Dickinson PCT, Hughes JEO, Holtzman RNN. The diagnosis and treatment of cerebral mycotic aneurysms. Ann Neurol 1990;27:238-46. 4. Devadiga KV, Mathai KV, Chandy J. Case reports and technical notes: spontaneous cure of intracavernous aneurysm of the internal carotid artery in a 14-month-old child. J Neurosurg 1969;30:165-8. 5. Eguchi T, Nakagomi T, Teraoka A. Treatment of bilateral mycotic intracavernous carotid aneurysms. J Neurosurg 1982;56:443-7. 6. Fujii K, Chambers SM, Rhoton AFJr. Neurovascular relationships of the sphenoid sinus: a microsurgical study. J Neurosurg 1979;50:31-9. 7. Isaacs BA, van Dellen JR. Persistence of a mycotic aneurysm of the intracavernous carotid artery. Surg Neurol 1986;26:577-80. 8. Johnson I. Direct surgical treatment of bilateral intracavernous internal carotid artery aneurysms. J Neurosurg 1979;51:98-102. 9. Lansky LL, MaxwellJA. Mycotic aneurysm of the internal carotid artery in an unusual intra-cranial location. Dev Med. Child Neurol 1975;17:79-88. 10. Lasjaunias P, Berenstein A. Surgical neuroangiography. Vol 2: Endovascular treatment of craniofacial lesions, 235-71. 11. Rout D, McAnn PK, Rao VRK. Bacterial aneurysms of the intracavernous carotid artery, case report. J Neurosurg 1984;60:1236-42.
We have reported a case of bacterial aneurysm of the ICA and reviewed the literature regarding previous cases. The potentially useful role of MRI in both diagnosis and following of such cases was noted as was the usefulness of endovascular occlusion should antibiotic therapy fail to lead to aneurysm resolution.
13. Suwanwela C, Suwanwela N, Srisakul C, Hongsaprabhasc C. Intracranial mycotic aneurysms of extravascular origin. J Neurosurg 1972;36:552-9.
References
14. Tomita T, McLone DG, Naidich TP. Mycotic aneurysm of the intracavernous portion of the carotid artery in childhood. J Neurosurg 1981;54:681-4.
1. Adeloye A, Sigh SP, Osinowo O: Extravascular mycotic aneurysm of the intracavernous portion of the internal carotid artery. West African Med J 1973;22:44-66.
12. Shibuya S, Igarashi S, Amo T, Sato H, Fukumitsu T. Mycotic aneurysms of the internal carotid artery. J Neurosurg 1976;44:105-8.
15. Whitehead E, DeSouza FM. Acute sphenoid sinusitis causing spasm of the internal carotid artery. Can J Otolaryngol. 1974;32:216-8.
