The Neuroradiology Journal 21: 251-254, 2008
www. centauro. it
Distal Anterior Cerebral Artery Aneurysms: Endovascular or Surgical Treatment? A Case Report
R. SAPONIERO, A. TORIELLO*, G. LOCATELLI, N.D. PUGLIESE*, A.N. NAPOLI, M. NAPOLI, A. SIANI, G. CUOMO, M.P. PANZA, N. NARCISO**, L. POSTERARO** Neuroradiology Unit, *Neurological Rehabilitation Unit, **Neurosurgery Unit Giovanni di Dio e Ruggi d’Aragona Specialist Hospital; Salerno, Italy
Key words: azygos anterior cerebral aneurysm, subarachnoid hemorrage, pathology
SUMMARY – Cerebral aneurysms are occasionally associated with anomalies of the cerebral arteries. Most reports on anomalies of the anterior cerebral artery have been concerned with hypoplasia, fenestration and the infra-optic course of the A1, variant A1 perforators or Heubner’s artery, multichanneled anterior communicating artery, and azygos anterior cerebral artery. Distal anterior cerebral artery (ACA) aneurysms are known to have a poor clinical course and prognosis compared to other supratentorial aneurysms. The presence of the unpaired, distal, postcommunicating (A2) segment of the ACA is very rare in adults. We describe a patient with a ruptured aneurysm arising from the proximal end of the azygos ACA, first surgically treated with clipping and then with endovascular coiling. A 37-year-old woman at 34 weeks’ gestation was transferred to our emergency room with sudden onset of severe headache and vomiting. Computed tomography (CT) revealed subarachnoid hemorrhage in the basal cisterna and the sylvian and interhemispheric fissures. Cerebral angiography showed an azygos ACA, a saccular aneurysm at the junction of the azygos ACA and the right A1 segment. A right fronto-temporal craniotomy was performed in the day of admission, and the neck of the aneurysm was clipped. One year later, an angiographic control examination revealed a regrowth of the aneurysm. The patient underwent endovascular treatment with coiling. Aneurysms of the azygos ACA are rare and their pathogenesis and course are still a matter of discussion. Developmental abnormalities or dynamic vessel wall stresses can explain the high incidence of aneurysms in these cases. The association of a rare anatomical variant with an aneurysm in the same location may suggest an embryogenesis alteration in the Willis circulation.
Introduction Subarachnoid hemorrhage mortality is approximately 50% and the majority of patients that survive have permanent disability. Recent advances in interventional neurosurgery and neuroradiology have underlined new aspects in the treatment of cerebral aneurysms. In particular, the ISAT study suggested that endovascular treatment with coiling in patients with aneurysms with a diameter equal or inferior to 10 mm have a favorable anatomical configuration for endovascular treatment with coil placement, and offer the best outcome in comparison to surgical clipping 1. The management of these
patients always requires advanced intensive therapy and cooperation between neurologists, neuroradiologists and neurosurgeons. Since 1996, 348 patients have undergone endovascular treatment at our institution for aneurysms of the anterior and posterior circulation, of which around 10% for non ruptured aneurysms. The presence of a distal single segment, post-communicating (A2) anterior (ACA) cerebral artery is rare in adults (anterior cerebral artery azygos-AACA), having constituted from 1.5% to 9% of all aneurysms of the cerebral circulation 2 . In our series, the incidence of azygos ACA is 0.27%. The azygos ACA is closely associated to saccular aneurysms, with an incidence that 251
Distal Anterior Cerebral Artery Aneurysms: Endovascular or Surgical Treatment?
R. Saponiero
Figure 2 Right carotid angiograms in anteroposterior projection showing the typical aneurysm of the AACA.
Figure 1 Image of the pericallosal artery and its relation with other arteries of the anterior cerebral circulation.
Figure 3 Right angiograms showing regrowth of the AACA aneurysm.
has varied from 41% to 71%. They are usually located in the pericalloso-callosomarginal bifurcation (figure 1). They can mimic aneurysms of the communicating anterior artery at conventional angiographic examination, because the AACA can appear as two segments A2 overlapping in lateral projection. Multiple angiographic projections would be required in doubtful cases to distinguish between these two locations as each involves a different surgical strategy. Aneurysms of the AACA have a higher mortality
and morbidity than other aneurysms of the anterior circulation. In particular, surgical mortality is superior to 32% (3). The endovascular treatment of a ruptured aneurysm of the AACA should be considered a valid alternative to surgical clipping (figures 4,5). Few cases of aneurysms have been described in association with the AACA till now in the literature. We describe another case of aneurysm of the AACA, treated at first with surgical clipping and subsequently with endovascular coiling.
252
www. centauro. it
↑ Figure 4
The Neuroradiology Journal 21: 251-254, 2008
↓ Figure 5
as 2. She had no neurological abnormalities except neck stiffness. Laboratory examinations were almost normal. Computed tomography (CT) revealed subarachnoid hemorrage in the basal cisterna and the sylvian and interhemispheric fissures. Conventional cerebral angiography showed an azygos ACA, a saccular aneurysm at the junction of the azygos ACA and the right A1 segment (figure 2). After induction of the birth, she underwent right frontotemporal craniotomy and an emergent clipping operation was performed on the day of admission, and the neck of the aneurysm was clipped. The postoperative course was uneventful, post-operative control angiogram was performed three weeks later and the patient was discharged one month after admission without neurological deficits, evaluated by the Functional Independence Measure (FIM). One year later, angiographic control revealed a regrowth of the aneurysm (figure 3). At this time the patient received endovascular treatment with GDC coil deployment (microcatheter 10 Fs; microguide 10 Fs) (figures 4, 5). Discussion
Figures 4 and 5 Right angiograms in anteroposterior projection showing the previous clipping and the subsequent coiling (picture 4 with subtracted images and picture 5 without subtracted images).
Case Report A 37-year-old woman at 34° weeks’ gestation was transferred to our emergency room with sudden onset of severe headache and nausea. The headache was aggravated by running or shaking the head, and rapidly increased in severity. On admission, she was alert and cooperative. Her Glasgow Coma Scale was 14 (eye opening 3, verbal 5, motor 6). The patient was classified according to the Hunt and Hess Scale
Aneurysms of the AACA are rare. Most of these aneurysms arise at the bifurcation formed by the origin of the callosomarginal artery from the pericallosal artery. Common characteristics of these aneurysms need to be identified, such as the coexistence of other aneurysms, clinical symptoms and technical challenges. The pathogenesis, namely the sequence of steps and the biological dynamics underlying spontaneous aneurysms remain a matter of discussion. The AACA can result from the fusion of the coupled A2 segments from the medial branch of the primitive olfactory artery to about 40 days of pregnancy, or from the persistence of the median artery of the callous body around the 44th day of pregnancy and from the concomitant regression of the A2 segments. Some alterations of the development or haemodynamic stress on altered vascular structures could explain the high incidence of aneurysms in this location. Distal anterior cerebral artery (ACA) aneurysms are known to have poor clinical course and prognosis compared to other supratentorial aneurysms, as well as relatively high morbidity and mortality rates 2,6,7. Ruptured aneurysms of the distal ACA and its associated branches are relatively uncommon, comprising approximately 5% of all intracranial aneurysms. The 253
Distal Anterior Cerebral Artery Aneurysms: Endovascular or Surgical Treatment?
presence of an unpaired, distal, postcommunicating (A2) segment of the ACA is very rare in adults. Aneurysms of the azygos anterior cerebral artery (AACA) were found in 41% of identified cases of Huber et Al’s series of 17 unpaired pericallosal trunks 8. Few cases of aneurysms in association with the AACA have been described to date. Anatomical variants of the cerebral arteries in general are due to the complex ontogenesis of these structures. Although encountered in many mammals, a single anterior cerebral artery (ACA) trunk is an infrequent finding in humans with an incidence of 3-5%. This vessel, giving rise to the arteries of both frontal lobes, is subjected to high flow volumes and distal arterial aneurysms have repeatedly been encountered, mostly however before the introduction of endovascular treatment strategies. Aneurysms of the AACA are almost always located at the distal bifurcation, and rarely at the proximal end. Proximal AACA aneurysm can mimic anterior communicating artery aneurysm. Therefore, accurate preoperative diagnosis is critical using 3D CT angiography as well as conventional angiography, and close follow-up of the patient is necessary to monitor for development of a de novo aneurysm at the distal bifurcation of the AACA. Due to the higher mortality and
R. Saponiero
morbility than other aneurysms of the anterior circulation, and, particularly, the surgical mortality superior to 32%, the endovascular treatment of a ruptured aneurysm of the AACA should be considered a valid alternative to surgical clipping. Eleven out of 12 ruptured aneurysms of the AACA were effectively occluded by endovascular treatment with coiling in the cases of Menovsky 4. Giant aneurysms of the AACA are extremely rare, and tend to rupture when of small dimensions. Therefore, they should be aggressively treated even when very small, and endovascular treatment constitutes an alternative in the management of these aneurysms 5. Endovascular treatment of AACA aneurysms is feasible and has a good outcome despite the technical difficulties and a high procedure-related rupture rate 9. The case described confirms the good outcome of the treatment. Aneurysms of AACA are rare and their pathogenesis and course remain a matter of discussion 10-12. Developmental abnormalities or dynamic vessel wall stresses can explain the high incidence of aneurysms in this case. In our patient, the association of a rare anatomical variant with an aneurysm in the same location could confirm the hypothesis of embryogenesis alteration of the Willis circulation.
References 1 ISAT Trial: Ciling or clipping for intracranial aneurysms? Lancet 366: 783-785, 2005. 2 Mann KS et Al: Aneurysms of the pericallosal-callosomarginal junction. Surg Neurol 21: 261-266, 1984. 3 De Sousa AA et Al: Distal anterior cerebral artery aneurysms. Surg Neurol 52: 128-136, 1999. 4 Menovsky T et Al: Coiling of ruptured pericallosal artery aneurysms. Neurosurgery 50: 11-14, 2002. 5 Dinc C et Al: Distal Anterior Cerebral Artery Aneurysms-Report of 26 Cases. Neurol Med Chir 46: 575580, 2006 6 Snyckers FD, Drake CG: Aneurysms of the distal anterior cerebral artery. A report on 24 verified cases. S Afr Med 47: 1787-1791, 1973. 7 Yasargil MG, Carter LP: Saccular aneurysms of the distal anterior cerebral artery. J Neurosurg 39: 218223, 1974. 8 Huber P et Al: Incidence of berry aneurysms of the unpaiired pericallosal artery: angiographic study. Neuroradiology 19: 143-147,1980. 9 Keston P et Al: The endovascular management of pericallosal artery aneurysms. J Neuroradiology 31: 384390, 2004. 10 Shievink WI: Genetics and aneurysm formation. Neurosurg Clin N Am 9: 485-495, 1998.
254
11 Milenkovic et Al: The azygos anterior cerebral artery aneurysms confirmed at operation. Medicine and Biology 4: 40-43, 1997. 12 Pavlovic et Al: Arteria Pericallosa azygos. II Congress of Neuroscience. Kotor: 29, 1995.
Renato Saponiero, MD Dipartimento di Neuroradiologia Azienda Ospedaliera di Alta Specialità Via S. Leonardo 84131 Salerno, Italy Tel.: +393394142143 Fax: +39089672559 E-mail: [email protected]
www. centauro. it
Distal Anterior Cerebral Artery Aneurysms: Endovascular or Surgical Treatment? A Case Report
R. SAPONIERO, A. TORIELLO*, G. LOCATELLI, N.D. PUGLIESE*, A.N. NAPOLI, M. NAPOLI, A. SIANI, G. CUOMO, M.P. PANZA, N. NARCISO**, L. POSTERARO** Neuroradiology Unit, *Neurological Rehabilitation Unit, **Neurosurgery Unit Giovanni di Dio e Ruggi d’Aragona Specialist Hospital; Salerno, Italy
Key words: azygos anterior cerebral aneurysm, subarachnoid hemorrage, pathology
SUMMARY – Cerebral aneurysms are occasionally associated with anomalies of the cerebral arteries. Most reports on anomalies of the anterior cerebral artery have been concerned with hypoplasia, fenestration and the infra-optic course of the A1, variant A1 perforators or Heubner’s artery, multichanneled anterior communicating artery, and azygos anterior cerebral artery. Distal anterior cerebral artery (ACA) aneurysms are known to have a poor clinical course and prognosis compared to other supratentorial aneurysms. The presence of the unpaired, distal, postcommunicating (A2) segment of the ACA is very rare in adults. We describe a patient with a ruptured aneurysm arising from the proximal end of the azygos ACA, first surgically treated with clipping and then with endovascular coiling. A 37-year-old woman at 34 weeks’ gestation was transferred to our emergency room with sudden onset of severe headache and vomiting. Computed tomography (CT) revealed subarachnoid hemorrhage in the basal cisterna and the sylvian and interhemispheric fissures. Cerebral angiography showed an azygos ACA, a saccular aneurysm at the junction of the azygos ACA and the right A1 segment. A right fronto-temporal craniotomy was performed in the day of admission, and the neck of the aneurysm was clipped. One year later, an angiographic control examination revealed a regrowth of the aneurysm. The patient underwent endovascular treatment with coiling. Aneurysms of the azygos ACA are rare and their pathogenesis and course are still a matter of discussion. Developmental abnormalities or dynamic vessel wall stresses can explain the high incidence of aneurysms in these cases. The association of a rare anatomical variant with an aneurysm in the same location may suggest an embryogenesis alteration in the Willis circulation.
Introduction Subarachnoid hemorrhage mortality is approximately 50% and the majority of patients that survive have permanent disability. Recent advances in interventional neurosurgery and neuroradiology have underlined new aspects in the treatment of cerebral aneurysms. In particular, the ISAT study suggested that endovascular treatment with coiling in patients with aneurysms with a diameter equal or inferior to 10 mm have a favorable anatomical configuration for endovascular treatment with coil placement, and offer the best outcome in comparison to surgical clipping 1. The management of these
patients always requires advanced intensive therapy and cooperation between neurologists, neuroradiologists and neurosurgeons. Since 1996, 348 patients have undergone endovascular treatment at our institution for aneurysms of the anterior and posterior circulation, of which around 10% for non ruptured aneurysms. The presence of a distal single segment, post-communicating (A2) anterior (ACA) cerebral artery is rare in adults (anterior cerebral artery azygos-AACA), having constituted from 1.5% to 9% of all aneurysms of the cerebral circulation 2 . In our series, the incidence of azygos ACA is 0.27%. The azygos ACA is closely associated to saccular aneurysms, with an incidence that 251
Distal Anterior Cerebral Artery Aneurysms: Endovascular or Surgical Treatment?
R. Saponiero
Figure 2 Right carotid angiograms in anteroposterior projection showing the typical aneurysm of the AACA.
Figure 1 Image of the pericallosal artery and its relation with other arteries of the anterior cerebral circulation.
Figure 3 Right angiograms showing regrowth of the AACA aneurysm.
has varied from 41% to 71%. They are usually located in the pericalloso-callosomarginal bifurcation (figure 1). They can mimic aneurysms of the communicating anterior artery at conventional angiographic examination, because the AACA can appear as two segments A2 overlapping in lateral projection. Multiple angiographic projections would be required in doubtful cases to distinguish between these two locations as each involves a different surgical strategy. Aneurysms of the AACA have a higher mortality
and morbidity than other aneurysms of the anterior circulation. In particular, surgical mortality is superior to 32% (3). The endovascular treatment of a ruptured aneurysm of the AACA should be considered a valid alternative to surgical clipping (figures 4,5). Few cases of aneurysms have been described in association with the AACA till now in the literature. We describe another case of aneurysm of the AACA, treated at first with surgical clipping and subsequently with endovascular coiling.
252
www. centauro. it
↑ Figure 4
The Neuroradiology Journal 21: 251-254, 2008
↓ Figure 5
as 2. She had no neurological abnormalities except neck stiffness. Laboratory examinations were almost normal. Computed tomography (CT) revealed subarachnoid hemorrage in the basal cisterna and the sylvian and interhemispheric fissures. Conventional cerebral angiography showed an azygos ACA, a saccular aneurysm at the junction of the azygos ACA and the right A1 segment (figure 2). After induction of the birth, she underwent right frontotemporal craniotomy and an emergent clipping operation was performed on the day of admission, and the neck of the aneurysm was clipped. The postoperative course was uneventful, post-operative control angiogram was performed three weeks later and the patient was discharged one month after admission without neurological deficits, evaluated by the Functional Independence Measure (FIM). One year later, angiographic control revealed a regrowth of the aneurysm (figure 3). At this time the patient received endovascular treatment with GDC coil deployment (microcatheter 10 Fs; microguide 10 Fs) (figures 4, 5). Discussion
Figures 4 and 5 Right angiograms in anteroposterior projection showing the previous clipping and the subsequent coiling (picture 4 with subtracted images and picture 5 without subtracted images).
Case Report A 37-year-old woman at 34° weeks’ gestation was transferred to our emergency room with sudden onset of severe headache and nausea. The headache was aggravated by running or shaking the head, and rapidly increased in severity. On admission, she was alert and cooperative. Her Glasgow Coma Scale was 14 (eye opening 3, verbal 5, motor 6). The patient was classified according to the Hunt and Hess Scale
Aneurysms of the AACA are rare. Most of these aneurysms arise at the bifurcation formed by the origin of the callosomarginal artery from the pericallosal artery. Common characteristics of these aneurysms need to be identified, such as the coexistence of other aneurysms, clinical symptoms and technical challenges. The pathogenesis, namely the sequence of steps and the biological dynamics underlying spontaneous aneurysms remain a matter of discussion. The AACA can result from the fusion of the coupled A2 segments from the medial branch of the primitive olfactory artery to about 40 days of pregnancy, or from the persistence of the median artery of the callous body around the 44th day of pregnancy and from the concomitant regression of the A2 segments. Some alterations of the development or haemodynamic stress on altered vascular structures could explain the high incidence of aneurysms in this location. Distal anterior cerebral artery (ACA) aneurysms are known to have poor clinical course and prognosis compared to other supratentorial aneurysms, as well as relatively high morbidity and mortality rates 2,6,7. Ruptured aneurysms of the distal ACA and its associated branches are relatively uncommon, comprising approximately 5% of all intracranial aneurysms. The 253
Distal Anterior Cerebral Artery Aneurysms: Endovascular or Surgical Treatment?
presence of an unpaired, distal, postcommunicating (A2) segment of the ACA is very rare in adults. Aneurysms of the azygos anterior cerebral artery (AACA) were found in 41% of identified cases of Huber et Al’s series of 17 unpaired pericallosal trunks 8. Few cases of aneurysms in association with the AACA have been described to date. Anatomical variants of the cerebral arteries in general are due to the complex ontogenesis of these structures. Although encountered in many mammals, a single anterior cerebral artery (ACA) trunk is an infrequent finding in humans with an incidence of 3-5%. This vessel, giving rise to the arteries of both frontal lobes, is subjected to high flow volumes and distal arterial aneurysms have repeatedly been encountered, mostly however before the introduction of endovascular treatment strategies. Aneurysms of the AACA are almost always located at the distal bifurcation, and rarely at the proximal end. Proximal AACA aneurysm can mimic anterior communicating artery aneurysm. Therefore, accurate preoperative diagnosis is critical using 3D CT angiography as well as conventional angiography, and close follow-up of the patient is necessary to monitor for development of a de novo aneurysm at the distal bifurcation of the AACA. Due to the higher mortality and
R. Saponiero
morbility than other aneurysms of the anterior circulation, and, particularly, the surgical mortality superior to 32%, the endovascular treatment of a ruptured aneurysm of the AACA should be considered a valid alternative to surgical clipping. Eleven out of 12 ruptured aneurysms of the AACA were effectively occluded by endovascular treatment with coiling in the cases of Menovsky 4. Giant aneurysms of the AACA are extremely rare, and tend to rupture when of small dimensions. Therefore, they should be aggressively treated even when very small, and endovascular treatment constitutes an alternative in the management of these aneurysms 5. Endovascular treatment of AACA aneurysms is feasible and has a good outcome despite the technical difficulties and a high procedure-related rupture rate 9. The case described confirms the good outcome of the treatment. Aneurysms of AACA are rare and their pathogenesis and course remain a matter of discussion 10-12. Developmental abnormalities or dynamic vessel wall stresses can explain the high incidence of aneurysms in this case. In our patient, the association of a rare anatomical variant with an aneurysm in the same location could confirm the hypothesis of embryogenesis alteration of the Willis circulation.
References 1 ISAT Trial: Ciling or clipping for intracranial aneurysms? Lancet 366: 783-785, 2005. 2 Mann KS et Al: Aneurysms of the pericallosal-callosomarginal junction. Surg Neurol 21: 261-266, 1984. 3 De Sousa AA et Al: Distal anterior cerebral artery aneurysms. Surg Neurol 52: 128-136, 1999. 4 Menovsky T et Al: Coiling of ruptured pericallosal artery aneurysms. Neurosurgery 50: 11-14, 2002. 5 Dinc C et Al: Distal Anterior Cerebral Artery Aneurysms-Report of 26 Cases. Neurol Med Chir 46: 575580, 2006 6 Snyckers FD, Drake CG: Aneurysms of the distal anterior cerebral artery. A report on 24 verified cases. S Afr Med 47: 1787-1791, 1973. 7 Yasargil MG, Carter LP: Saccular aneurysms of the distal anterior cerebral artery. J Neurosurg 39: 218223, 1974. 8 Huber P et Al: Incidence of berry aneurysms of the unpaiired pericallosal artery: angiographic study. Neuroradiology 19: 143-147,1980. 9 Keston P et Al: The endovascular management of pericallosal artery aneurysms. J Neuroradiology 31: 384390, 2004. 10 Shievink WI: Genetics and aneurysm formation. Neurosurg Clin N Am 9: 485-495, 1998.
254
11 Milenkovic et Al: The azygos anterior cerebral artery aneurysms confirmed at operation. Medicine and Biology 4: 40-43, 1997. 12 Pavlovic et Al: Arteria Pericallosa azygos. II Congress of Neuroscience. Kotor: 29, 1995.
Renato Saponiero, MD Dipartimento di Neuroradiologia Azienda Ospedaliera di Alta Specialità Via S. Leonardo 84131 Salerno, Italy Tel.: +393394142143 Fax: +39089672559 E-mail: [email protected]
