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Embolization of a ruptured aneurysm of the distal anterior inferior cerebellar artery:
Endovascular
Embolization of a Ruptured Aneurysm of the Distal Anterior Inferior Cerebellar Artery: CASE REPORT AND REVIEW OF THE LITERATURE Kensuke Suzuki, M.D.,* Kotoo Meguro, M.D., F.R.S.(C),* Mitsuyoshi Wada, M.D.,† Keisi Fujita, M.D.* and Tadao Nose, M.D.‡ Department of *Neurosurgery and †Department of Radiology, Tsukuba Medical Center Hospital, and ‡Department of Neurosurgery, University of Tsukuba, Japan
Suzuki K, Meguro K, Wada M, Fujita K, Nose T. Embolization of a ruptured aneurysm of the distal anterior inferior cerebellar artery: Case report and review of the literature. Surg Neurol 1999;51:509 –12. BACKGROUND
Aneurysms of the distal anterior inferior cerebellar artery (AICA) are rare and almost all of them have been treated surgically, by wrapping or trapping, in the previous literature. Most cases of aneurysms associated with the auditory artery resulted in a hearing disturbance from the surgical procedure, although aneurysms far from the auditory artery had no deficit from trapping. METHODS
An 81-year-old woman presented with a ruptured aneurysm of the distal AICA. We planned a delayed treatment with intravascular embolization because of her advanced age and poor clinical status. Embolization of the distal anterior inferior cerebellar artery using detachable coils remote from the auditory artery was successful. RESULTS
Magnetic resonance imaging after embolization demonstrated no remaining lesion. The patient has been through rehabilitation and has gradually improved. CONCLUSION
Intravascular treatment of distal AICA aneurysms remote from the auditory artery may be safer and simpler than surgical treatment. © 1999 by Elsevier Science Inc. KEY WORDS
Cerebral aneurysm, anterior inferior cerebellar artery, embolization.
pproximately 0.1% [24] of cerebral aneurysms occur in the distal anterior inferior cerebellar artery (AICA) and only 31 cases have been reported in the literature [2,3,5–13,15–23,26 –30]. In particu-
A
Received January 17, 1997; accepted June 23, 1997. © 1999 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
lar, aneurysms of the far distal AICA that are unrelated to the auditory artery are extremely rare; only three cases have been reported to date [4,20,22]. Most distal AICA aneurysms have been treated surgically with neck clipping, wrapping, or trapping, although such surgical treatments often have resulted in cranial nerve paresis. We describe an 81year-old woman with a distal AICA aneurysm successfully treated with intravascular embolization. We suggest that intravascular embolization for aneurysms of the distal AICA may be safer and simpler than surgical treatments.
Case Report An 81-year-old woman developed sudden onset of headache and vomiting. She was transported by ambulance to the hospital. She lost consciousness en route and was comatose on admission. Computed tomography demonstrated subarachnoid hemorrhage with a hematoma in the posterior fossa (Figure 1) and acute noncommunicating hydrocephalus. Cerebral angiography revealed an aneurysm of the distal left AICA (Figure 2). We performed right cerebral ventricle drainage and planned delayed treatment for the aneurysm because of her advanced age and poor clinical status. The patient received short-acting barbiturates for 6 days to protect against re-rupture. Cerebral angiography was repeated 8 days later and there was no evidence of vasospasm. The size of the aneurysm and related arterial branches did not show any change from the initial angiogram. She became semicomatose for 2 weeks and did not respond to 0090-3019/99/$–see front matter PII S0090-3019(97)00462-X
510 Surg Neurol 1999;51:509 –12
Suzuki et al
Intravascular embolization and postembolization imaging. Superselective catheterization of the branch of the AICA distal to the meatal loop.
3
An 81-year-old woman with a ruptured distal AICA (anterior inferior cerebellar artery) aneurysm. The patient developed sudden onset headache and vomiting, and was comatose on arrival at the hospital. Computed tomography scan shows diffuse subarachnoid hemorrhage and hematoma in the posterior fossa.
1
verbal commands. Magnetic resonance imaging (MRI) demonstrated no lesions in the cerebral hemispheres or brainstem except for the original cerebellar hematoma. Lower cranial nerve paresis was difficult to evaluate due to the patient’s semicomatose state. We planned intravascular embolization using coils, which was performed 18 days after admission. A 7 Fr introducer sheath was inserted into the right brachial artery and a 6 Fr catheter was placed in the right vertebral artery. A Tracker catheter® was inserted into a distal branch
2
Right vertebral angiography (Anterior-posterior projection) shows an aneurysm at the distal AICA.
of the left AICA (Figure 3), and three fibered platinum coils (2 3 3 cm) were deployed in a peripheral branch through a loop to the auditory meatus. Embolization of the distal AICA was successful and the aneurysm was obliterated (Figure 4). The patient’s condition improved slightly and she was able to speak a few words. Auditory brainstem evoked potentials (ABR) and MRI demonstrated no complication after embolization (Figure 5).
Discussion Aneurysms of the distal AICA are extremely rare. Suzuki et al have reported only four distal AICA aneurysms among 3,899 cerebral aneurysms, and the incidence of the distal AICA aneurysms was only 3% of aneurysms in the posterior fossa (among 128 cases) [24]. To our knowledge, only 32 cases of
After three embolization coils were deployed, a right vertebral angiogram shows occlusion of the AICA branch and the aneurysm is no longer visualized.
4
Aneurysm of the Distal AICA
Surg Neurol 511 1999;51:509 –12
moses with the superior cerebellar artery (SCA) and posterior inferior cerebellar artery (PICA) [25]. Akar et al reported that the branches of the AICA that supply the inferior upper part of the olive arise 3–18 mm distal to the origin of the AICA, although occlusion of the AICA has been reported to lead to the lateral inferior pontine syndrome [1]. The AICA territory in the brainstem is shared by branches of the basilar artery, and the cerebellar branches of the AICA have anastomoses with the PICA and the (SCA) [14]. We concluded that obstruction of the AICA distal to the auditory artery should not result in a new deficit because this aneurysm was located on a hemispheric branch that had an anastomosis with the PICA. MRI after embolization demonstrated no new lesion and the ABR showed no abnormality. Several months after embolization, the patient has begun to respond to verbal commands and to speak words. MRI (SE:256, TR:4000, TE:110) shows no lesion other than the original hemorrhage in the cerebellar hemisphere.
5
distal AICA aneurysms, including this patient, have been reported [2,3,5–13,15–23,26 –30]. Of these, 23 cases (71.9%) were related to the meatal loop. Five aneurysms arose from a more proximal aspect of the auditory artery. Thirty patients were treated surgically (17 neck clipping, 4 wrapping, 3 trapping, 4 ligation, 2 unknown). The remaining patient died prior to surgery. Twenty patients had residual cranial nerve paresis after surgery. Only four (12.5%) patients (including this patient) presented with aneurysms which had no relationship with the auditory artery, at the far distal aspect of the AICA [4,20,22]. Two patients with aneurysms of the far distal AICA also had arteriovenous malformations in the posterior fossa [4,22]. Aneurysms at the meatal loop, which are associated with the auditory artery, have been treated using suboccipital or retromastoid approaches. Some patients who underwent these operations had facial or acoustic nerve palsy after surgery. This patient’s aneurysm, which was located far from the auditory artery, did not produce a cranial nerve deficit before treatment. We chose intravascular embolization because of her advanced age, poor clinical state, and the anatomic character of the AICA. The AICA usually arises from the basilar trunk, and its first branch is a medial branch, after which the AICA makes a meatal loop where it gives off the internal auditory artery. The AICA terminates in a few hemispheric branches which have anasto-
REFERENCES 1. Akar ZC, Dujovny M, Gomez-Tortosa E, Slavin KV, Ausman JI. Microvascular anatomy of the anterior surface of the medulla oblongata and olive. J Neurosurg 1995;82:97–105. 2. Cantore GP, Ciappetta P, Vagnozzi R, Bozzao L. Giant aneurysm of the anterior inferior cerebellar artery simulating a cerebellopontine angle tumor. Surg Neurol 1982;18:76 – 8. 3. Dalley RW, Robertson WD, Nugent RA, Durity FA. Computed tomography of anterior inferior cerebellar artery aneurysm mimicking an acoustic neuroma. J Comput Assist Tomog 1986;15:881– 4. 4. Fukuya T, Kishikawa T, Ikeda J, Kudo S, Kuwano H, Matsumoto S, Fujii K. Aneurysms of the peripheral portion of the anterior inferior cerebellar artery: report of two cases. Neuroradiology 1987;29:493– 6. 5. Gacs G, Vinuela F, Fox AJ, Drake C. Peripheral aneurysms of the cerebellar arteries: review of 16 cases. J Neurosurg 1983;58:63– 8. 6. Gleeson MJ, Cox TCS, Strong AJ. Aneurysm of the anterior inferior cerebellar artery mimicking an intracanalicular acoustic neuroma. J Laryngol Otol 1989; 103:107–10. 7. Higuchi H, Yajima K, Nakazawa S. A case of aneurysm of the left internal acoustic meatus. No-Shinkei-Geka 1978;6:401– 4. 8. Honda Y, Tanaka R, Kameyama S. Ruptured distal anterior inferior cerebellar artery aneurysm— case report. Neurol Med Chir (Tokyo) 1994;34:763–7. 9. Johnson JH Jr., Kline DG. Anterior inferior cerebellar artery aneurysm: case report. J Neurosurg 1978;48: 455– 69. 10. Kaech D, Tribolet N, Lasjaunias P. Anterior inferior cerebellar artery aneurysm, carotid bifurcation aneurysm, and dural arteriovenous malformation of the tentorium in the same patient. Neurosurgery 1987;21: 575– 82. 11. Kamano S, Kirino T, Mizuno S. Intrameatal aneurysm. Neurochirurgia 1986;29:28 –30. 12. Kiya K, Uozumi T, Emoto K, Matsuoka T. Anterior
512 Surg Neurol 1999;51:509 –12
13. 14.
15. 16. 17.
18.
19. 20.
21. 22. 23. 24. 25.
inferior cerebellar artery aneurysm at the inferior auditory meatus: case report. Neurol Med Chir (Tokyo) 1989;29:592–5. Malter IJ, Roberson G. Angiographic demonstration of anterior inferior cerebellar artery aneurysm by use of the base view. Radiology 1972;103:125– 6. Marinkovic SV, Gibo H, Stimec B. The neurovascular relationship and the blood supply of the abducent nerve: surgical anatomy of its cisternal segment. Neurosurgery 1994;34:1017–26. Mori K, Miyazaki H, Ona H. Aneurysm of the anterior inferior cerebellar artery at the internal auditory meatus. Surg Neurol 1978;10:297–300. Nakagawa K, Sakaki S, Kimura H, Matsuoka K. Aneurysm of the anterior inferior cerebellar artery at the internal auditory meatus. Surg Neurol 1984;21:231–5. Niijima K, Yonekawa Y. Neck clipping of an aneurysm at the basilar artery-anterior inferior cerebellar artery via presigmoid-transmastoideal approach. NoShinkei-Geka 1995;23:253–7. Nishimoto A, Fujimoto S, Tsutimoto S, Matsumoto Y, Tabuchi K, Higashi T. Anterior inferior cerebellar artery aneurysm: report of three cases. J Neurosurg 1983;59:697–702. Nowak G, Arnold H, Winkler D, Freckmann N. Aneurysma der arteria auditiva am porus acusticus internus. Neurochirurgia 1986;29:241–3. Oana K, Murakami T, Beppu T, Yamaura A, Kanaya H. Aneurysm of the distal anterior inferior cerebellar artery unrelated to the cerebellopontine angle: case report. Neurosurgery 1991;28:899 –903. Porter RJ, Eyster EF. Aneurysm in the anterior inferior cerebellar artery at the internal acoustic meatus: report of a case. Surg Neurol 1973;1:27– 8. Pritz MB. Aneurysms of the anterior inferior cerebellar artery. Acta Neurochir (Wien) 1993;120:12–9. Rinehart R, Harre RG, Roski R, Dolan K. Aneurysm of the anterior inferior cerebellar artery producing hearing loss. Ann Otol Rhinot Laryngol 1992;101:705– 6. Suzuki J, Hori S, Sakurai Y. Intracranial aneurysms in the neurosurgical clinics in Japan. J Neurosurg 1971; 35:34 –9. Takahashi M. The anterior inferior cerebellar artery. In: Newton TH, Potts DG, eds: Radiology of the Skull and Brain. Vol II, book 2, St. Louis: CV Mosby, 1974: 1796 –1808.
Suzuki et al
26. Takara E, Inoue N, Kohno H. Disappearance of the co-existing aneurysm and arteriovenous malformation after wrapping of aneurysm. No-Shinkei-Geka 1980;8:587–91. 27. Uede T, Mastumura S, Kurokawa Y, Ohtaki M, Tanabe S, Hsho K. Aneurysm of the anterior inferior cerebellar artery at the internal auditory meatus: report of two cases. No-Shinkei-Geka 1986;14: 1263– 8. 28. Yokoyana S, Kadota K, Asakura T, Kawazoe K. Aneurysm of the distal anterior inferior cerebellar artery— case report. Neurol Med Chir (Tokyo) 1995;35:587–90. 29. Zager EL. Isolated trigeminal sensory loss secondary to a distal anterior inferior cerebellar artery aneurysm: case report. Neurosurgery 1991;28:288 –91. 30. Zlotnik EI, Sklyut JA, Smejanovich AF, Stasenko EN. Saccular aneurysm of the anterior inferior cerebellarinternal auditory artery: case report. J Neurosurg 1982;57:829 –32.
COMMENTARY
The authors should be congratulated on having successfully treated with coils a ruptured aneurysm (Hunt/Hess Grade IV) of the distal AICA in an 81year-old female. These aneurysms are very rare, especially when they arise on the distal portion of the AICA beyond the origin of the auditory artery. It probably would have been easier and safer to treat this aneurysm with retrievable coils than with fibered nonretrievable coils. Surgery was considered contraindicated in this patient, because of her age and poor condition. Gerard Debrun, M.D. Departments of Neurosurgery and Radiology University of Illinois at Chicago Chicago, Illinois
Embolization of a Ruptured Aneurysm of the Distal Anterior Inferior Cerebellar Artery: CASE REPORT AND REVIEW OF THE LITERATURE Kensuke Suzuki, M.D.,* Kotoo Meguro, M.D., F.R.S.(C),* Mitsuyoshi Wada, M.D.,† Keisi Fujita, M.D.* and Tadao Nose, M.D.‡ Department of *Neurosurgery and †Department of Radiology, Tsukuba Medical Center Hospital, and ‡Department of Neurosurgery, University of Tsukuba, Japan
Suzuki K, Meguro K, Wada M, Fujita K, Nose T. Embolization of a ruptured aneurysm of the distal anterior inferior cerebellar artery: Case report and review of the literature. Surg Neurol 1999;51:509 –12. BACKGROUND
Aneurysms of the distal anterior inferior cerebellar artery (AICA) are rare and almost all of them have been treated surgically, by wrapping or trapping, in the previous literature. Most cases of aneurysms associated with the auditory artery resulted in a hearing disturbance from the surgical procedure, although aneurysms far from the auditory artery had no deficit from trapping. METHODS
An 81-year-old woman presented with a ruptured aneurysm of the distal AICA. We planned a delayed treatment with intravascular embolization because of her advanced age and poor clinical status. Embolization of the distal anterior inferior cerebellar artery using detachable coils remote from the auditory artery was successful. RESULTS
Magnetic resonance imaging after embolization demonstrated no remaining lesion. The patient has been through rehabilitation and has gradually improved. CONCLUSION
Intravascular treatment of distal AICA aneurysms remote from the auditory artery may be safer and simpler than surgical treatment. © 1999 by Elsevier Science Inc. KEY WORDS
Cerebral aneurysm, anterior inferior cerebellar artery, embolization.
pproximately 0.1% [24] of cerebral aneurysms occur in the distal anterior inferior cerebellar artery (AICA) and only 31 cases have been reported in the literature [2,3,5–13,15–23,26 –30]. In particu-
A
Received January 17, 1997; accepted June 23, 1997. © 1999 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
lar, aneurysms of the far distal AICA that are unrelated to the auditory artery are extremely rare; only three cases have been reported to date [4,20,22]. Most distal AICA aneurysms have been treated surgically with neck clipping, wrapping, or trapping, although such surgical treatments often have resulted in cranial nerve paresis. We describe an 81year-old woman with a distal AICA aneurysm successfully treated with intravascular embolization. We suggest that intravascular embolization for aneurysms of the distal AICA may be safer and simpler than surgical treatments.
Case Report An 81-year-old woman developed sudden onset of headache and vomiting. She was transported by ambulance to the hospital. She lost consciousness en route and was comatose on admission. Computed tomography demonstrated subarachnoid hemorrhage with a hematoma in the posterior fossa (Figure 1) and acute noncommunicating hydrocephalus. Cerebral angiography revealed an aneurysm of the distal left AICA (Figure 2). We performed right cerebral ventricle drainage and planned delayed treatment for the aneurysm because of her advanced age and poor clinical status. The patient received short-acting barbiturates for 6 days to protect against re-rupture. Cerebral angiography was repeated 8 days later and there was no evidence of vasospasm. The size of the aneurysm and related arterial branches did not show any change from the initial angiogram. She became semicomatose for 2 weeks and did not respond to 0090-3019/99/$–see front matter PII S0090-3019(97)00462-X
510 Surg Neurol 1999;51:509 –12
Suzuki et al
Intravascular embolization and postembolization imaging. Superselective catheterization of the branch of the AICA distal to the meatal loop.
3
An 81-year-old woman with a ruptured distal AICA (anterior inferior cerebellar artery) aneurysm. The patient developed sudden onset headache and vomiting, and was comatose on arrival at the hospital. Computed tomography scan shows diffuse subarachnoid hemorrhage and hematoma in the posterior fossa.
1
verbal commands. Magnetic resonance imaging (MRI) demonstrated no lesions in the cerebral hemispheres or brainstem except for the original cerebellar hematoma. Lower cranial nerve paresis was difficult to evaluate due to the patient’s semicomatose state. We planned intravascular embolization using coils, which was performed 18 days after admission. A 7 Fr introducer sheath was inserted into the right brachial artery and a 6 Fr catheter was placed in the right vertebral artery. A Tracker catheter® was inserted into a distal branch
2
Right vertebral angiography (Anterior-posterior projection) shows an aneurysm at the distal AICA.
of the left AICA (Figure 3), and three fibered platinum coils (2 3 3 cm) were deployed in a peripheral branch through a loop to the auditory meatus. Embolization of the distal AICA was successful and the aneurysm was obliterated (Figure 4). The patient’s condition improved slightly and she was able to speak a few words. Auditory brainstem evoked potentials (ABR) and MRI demonstrated no complication after embolization (Figure 5).
Discussion Aneurysms of the distal AICA are extremely rare. Suzuki et al have reported only four distal AICA aneurysms among 3,899 cerebral aneurysms, and the incidence of the distal AICA aneurysms was only 3% of aneurysms in the posterior fossa (among 128 cases) [24]. To our knowledge, only 32 cases of
After three embolization coils were deployed, a right vertebral angiogram shows occlusion of the AICA branch and the aneurysm is no longer visualized.
4
Aneurysm of the Distal AICA
Surg Neurol 511 1999;51:509 –12
moses with the superior cerebellar artery (SCA) and posterior inferior cerebellar artery (PICA) [25]. Akar et al reported that the branches of the AICA that supply the inferior upper part of the olive arise 3–18 mm distal to the origin of the AICA, although occlusion of the AICA has been reported to lead to the lateral inferior pontine syndrome [1]. The AICA territory in the brainstem is shared by branches of the basilar artery, and the cerebellar branches of the AICA have anastomoses with the PICA and the (SCA) [14]. We concluded that obstruction of the AICA distal to the auditory artery should not result in a new deficit because this aneurysm was located on a hemispheric branch that had an anastomosis with the PICA. MRI after embolization demonstrated no new lesion and the ABR showed no abnormality. Several months after embolization, the patient has begun to respond to verbal commands and to speak words. MRI (SE:256, TR:4000, TE:110) shows no lesion other than the original hemorrhage in the cerebellar hemisphere.
5
distal AICA aneurysms, including this patient, have been reported [2,3,5–13,15–23,26 –30]. Of these, 23 cases (71.9%) were related to the meatal loop. Five aneurysms arose from a more proximal aspect of the auditory artery. Thirty patients were treated surgically (17 neck clipping, 4 wrapping, 3 trapping, 4 ligation, 2 unknown). The remaining patient died prior to surgery. Twenty patients had residual cranial nerve paresis after surgery. Only four (12.5%) patients (including this patient) presented with aneurysms which had no relationship with the auditory artery, at the far distal aspect of the AICA [4,20,22]. Two patients with aneurysms of the far distal AICA also had arteriovenous malformations in the posterior fossa [4,22]. Aneurysms at the meatal loop, which are associated with the auditory artery, have been treated using suboccipital or retromastoid approaches. Some patients who underwent these operations had facial or acoustic nerve palsy after surgery. This patient’s aneurysm, which was located far from the auditory artery, did not produce a cranial nerve deficit before treatment. We chose intravascular embolization because of her advanced age, poor clinical state, and the anatomic character of the AICA. The AICA usually arises from the basilar trunk, and its first branch is a medial branch, after which the AICA makes a meatal loop where it gives off the internal auditory artery. The AICA terminates in a few hemispheric branches which have anasto-
REFERENCES 1. Akar ZC, Dujovny M, Gomez-Tortosa E, Slavin KV, Ausman JI. Microvascular anatomy of the anterior surface of the medulla oblongata and olive. J Neurosurg 1995;82:97–105. 2. Cantore GP, Ciappetta P, Vagnozzi R, Bozzao L. Giant aneurysm of the anterior inferior cerebellar artery simulating a cerebellopontine angle tumor. Surg Neurol 1982;18:76 – 8. 3. Dalley RW, Robertson WD, Nugent RA, Durity FA. Computed tomography of anterior inferior cerebellar artery aneurysm mimicking an acoustic neuroma. J Comput Assist Tomog 1986;15:881– 4. 4. Fukuya T, Kishikawa T, Ikeda J, Kudo S, Kuwano H, Matsumoto S, Fujii K. Aneurysms of the peripheral portion of the anterior inferior cerebellar artery: report of two cases. Neuroradiology 1987;29:493– 6. 5. Gacs G, Vinuela F, Fox AJ, Drake C. Peripheral aneurysms of the cerebellar arteries: review of 16 cases. J Neurosurg 1983;58:63– 8. 6. Gleeson MJ, Cox TCS, Strong AJ. Aneurysm of the anterior inferior cerebellar artery mimicking an intracanalicular acoustic neuroma. J Laryngol Otol 1989; 103:107–10. 7. Higuchi H, Yajima K, Nakazawa S. A case of aneurysm of the left internal acoustic meatus. No-Shinkei-Geka 1978;6:401– 4. 8. Honda Y, Tanaka R, Kameyama S. Ruptured distal anterior inferior cerebellar artery aneurysm— case report. Neurol Med Chir (Tokyo) 1994;34:763–7. 9. Johnson JH Jr., Kline DG. Anterior inferior cerebellar artery aneurysm: case report. J Neurosurg 1978;48: 455– 69. 10. Kaech D, Tribolet N, Lasjaunias P. Anterior inferior cerebellar artery aneurysm, carotid bifurcation aneurysm, and dural arteriovenous malformation of the tentorium in the same patient. Neurosurgery 1987;21: 575– 82. 11. Kamano S, Kirino T, Mizuno S. Intrameatal aneurysm. Neurochirurgia 1986;29:28 –30. 12. Kiya K, Uozumi T, Emoto K, Matsuoka T. Anterior
512 Surg Neurol 1999;51:509 –12
13. 14.
15. 16. 17.
18.
19. 20.
21. 22. 23. 24. 25.
inferior cerebellar artery aneurysm at the inferior auditory meatus: case report. Neurol Med Chir (Tokyo) 1989;29:592–5. Malter IJ, Roberson G. Angiographic demonstration of anterior inferior cerebellar artery aneurysm by use of the base view. Radiology 1972;103:125– 6. Marinkovic SV, Gibo H, Stimec B. The neurovascular relationship and the blood supply of the abducent nerve: surgical anatomy of its cisternal segment. Neurosurgery 1994;34:1017–26. Mori K, Miyazaki H, Ona H. Aneurysm of the anterior inferior cerebellar artery at the internal auditory meatus. Surg Neurol 1978;10:297–300. Nakagawa K, Sakaki S, Kimura H, Matsuoka K. Aneurysm of the anterior inferior cerebellar artery at the internal auditory meatus. Surg Neurol 1984;21:231–5. Niijima K, Yonekawa Y. Neck clipping of an aneurysm at the basilar artery-anterior inferior cerebellar artery via presigmoid-transmastoideal approach. NoShinkei-Geka 1995;23:253–7. Nishimoto A, Fujimoto S, Tsutimoto S, Matsumoto Y, Tabuchi K, Higashi T. Anterior inferior cerebellar artery aneurysm: report of three cases. J Neurosurg 1983;59:697–702. Nowak G, Arnold H, Winkler D, Freckmann N. Aneurysma der arteria auditiva am porus acusticus internus. Neurochirurgia 1986;29:241–3. Oana K, Murakami T, Beppu T, Yamaura A, Kanaya H. Aneurysm of the distal anterior inferior cerebellar artery unrelated to the cerebellopontine angle: case report. Neurosurgery 1991;28:899 –903. Porter RJ, Eyster EF. Aneurysm in the anterior inferior cerebellar artery at the internal acoustic meatus: report of a case. Surg Neurol 1973;1:27– 8. Pritz MB. Aneurysms of the anterior inferior cerebellar artery. Acta Neurochir (Wien) 1993;120:12–9. Rinehart R, Harre RG, Roski R, Dolan K. Aneurysm of the anterior inferior cerebellar artery producing hearing loss. Ann Otol Rhinot Laryngol 1992;101:705– 6. Suzuki J, Hori S, Sakurai Y. Intracranial aneurysms in the neurosurgical clinics in Japan. J Neurosurg 1971; 35:34 –9. Takahashi M. The anterior inferior cerebellar artery. In: Newton TH, Potts DG, eds: Radiology of the Skull and Brain. Vol II, book 2, St. Louis: CV Mosby, 1974: 1796 –1808.
Suzuki et al
26. Takara E, Inoue N, Kohno H. Disappearance of the co-existing aneurysm and arteriovenous malformation after wrapping of aneurysm. No-Shinkei-Geka 1980;8:587–91. 27. Uede T, Mastumura S, Kurokawa Y, Ohtaki M, Tanabe S, Hsho K. Aneurysm of the anterior inferior cerebellar artery at the internal auditory meatus: report of two cases. No-Shinkei-Geka 1986;14: 1263– 8. 28. Yokoyana S, Kadota K, Asakura T, Kawazoe K. Aneurysm of the distal anterior inferior cerebellar artery— case report. Neurol Med Chir (Tokyo) 1995;35:587–90. 29. Zager EL. Isolated trigeminal sensory loss secondary to a distal anterior inferior cerebellar artery aneurysm: case report. Neurosurgery 1991;28:288 –91. 30. Zlotnik EI, Sklyut JA, Smejanovich AF, Stasenko EN. Saccular aneurysm of the anterior inferior cerebellarinternal auditory artery: case report. J Neurosurg 1982;57:829 –32.
COMMENTARY
The authors should be congratulated on having successfully treated with coils a ruptured aneurysm (Hunt/Hess Grade IV) of the distal AICA in an 81year-old female. These aneurysms are very rare, especially when they arise on the distal portion of the AICA beyond the origin of the auditory artery. It probably would have been easier and safer to treat this aneurysm with retrievable coils than with fibered nonretrievable coils. Surgery was considered contraindicated in this patient, because of her age and poor condition. Gerard Debrun, M.D. Departments of Neurosurgery and Radiology University of Illinois at Chicago Chicago, Illinois