Multiple spontaneous dissecting aneurysms of the anterior cerebral and vertebral arteries

A 50-year-old woman presented with rare multiple dissecting aneurysms that appeared first in the anterior cerebral artery (ACA) and shortly afterwards in the vertebral artery (VA). She initially suffered sudden motor weakness in the left lower limb due to acute brain infarction. Angiography revealed diffuse string sign in the right ACA. Conservative treatment resulted in resolution of the deficits. Follow-up angiography performed 1 year later revealed recovery of the ACA stenosis. Fourteen days later, she complained of sudden headache and became comatose. Computed tomography showed diffuse subarachnoid hemorrhage. Angiography revealed a new right VA dissecting aneurysm involving the posterior inferior cerebellar artery (PICA). The orifice of the dissection was not apparent in the operative field and the dissection extended to the median. The patient underwent extracranial right VA ligation, clipping of the proximal PICA, and revascularization between the right occipital artery and distal PICA. Her postoperative course was uneventful and she was discharged without neurological deficits. VA dissecting aneurysms involving the PICA without evident orifice or extending over the median can be treated by extracranial ligation with clipping of the PICA, followed by revascularization.     

A case of neurofibromatosis type 1 associated with arteriovenous fistula caused by re-bleeding of a vertebral dissecting aneurysm

We described a dissecting aneurysm of the vertebral artery (VA), which was associated with neurofibromatosis type 1 (NF1). A 41-year-old man was referred to our hospital because of abrupt, severe headache. A CT scan revealed diffuse subarachnoid hemorrhage (SAH) predominantly in the prepontine cistern. The angiograms showed a string sign in the left VA, just distal to the posterior inferior cerebellar artery (PICA). The vertebral dissection was considered responsible for SAH, and endovascular occlusion of the left VA was attempted. During the intervention, the patient complained of severe neck pain at the time of selective vertebral angiography, which revealed an arteriovenous fistula. The VA was occluded proximal to the PICA with GDC, which covered the fistula. Open surgery confirmed the two unruptured aneurysms. Intracranial dissection is rarely reported in association with NF1. However, ateriovenous fistula is not an uncommon combination with dissecting aneurysm and the extracranial segment of the VA is a characteristic target. Anatomical feasibility is conceivably the pathogenesis.     

Case of spontaneous bilateral VA dissecting aneurysm presenting with SAH

We report a case of bilateral vertebral artery (VA) dissecting aneurysm presenting subarachnoid hemorrhage (SAH). It was difficult to decide which side was responsible for SAH because the patient's symptom and head CT suggested that the left VA aneurysm had ruptured, but angiography and MRA showed an irregular pearl and string sign on the right side. He was successfully treated by trapping of the right VA dissecting aneurysm and we confirmed by intraoperative evaluation that the right VA dissecting aneurysm had ruptured. The left unruptured aneurysm decreased its size spontaneously. In the treatment of the bilateral VA dissecting aneurysms, angiography needs to be performed over and over again because contralateral unruptured aneurysm may grow or rupture due to increased hemodynamic stress. Various combinations of direct sugery with or without arterial reconstruction and endovascular treatment should be considered when treating bilateral VA dissecting aneurysms.     

Subarachnoid hemorrhage caused by posterior inferior cerebellar artery aneurysm with an anomalous course of the atlantoaxial segment of the vertebral artery. Case report and review of literature

Various anatomical courses of the vertebral artery (VA) and posterior inferior cerebellar artery (PICA) have been described. The authors present a unique case of a subarachnoid hemorrhage resulting from an aneurysm in a patient with an anatomical variation of the extracranial portion of the VA and cervical origin of the PICA. The surgical implications of this variant are discussed, and the pertinent literature reviewed. Subarachnoid hemorrhage caused by rupture of a PICA aneurysm is reported for the first time in association with a rare variation of the course of the VA.     

Successful clipping of a distal posterior inferior cerebellar artery aneurysm located on the anterior surface of the medulla oblongata--case report

A 55-year-old male presented with a ruptured distal posterior inferior cerebellar artery (PICA) aneurysm manifesting as subarachnoid hemorrhage. Angiography demonstrated a saccular aneurysm arising from the lateral medullary segment of the left PICA and located on the medial side of the left vertebral artery (VA) and the anterior surface of the medulla oblongata. A transcondylar fossa approach was used to ensure a sufficient operating field and to obtain adequate visualization of the aneurysm, the parent artery, and the perforating arteries to the medulla oblongata. The aneurysm dome protruded medially at the hairpin curve, and was located on the medial side of the left VA and on the anterior surface of the medulla oblongata. There was no vessel branches in the vicinity of the aneurysm. The aneurysm was successfully clipped with minimum retraction of the cerebellar hemisphere and medulla oblongata. Distal PICA aneurysms can be located at various sites in the posterior fossa. The exact location of the aneurysm must be established to select the best surgical approach.     

Development of a dissecting aneurysm on the vertebral artery immediately after occlusion of the contralateral vertebral artery: A case report

A 49 year old female presented with subarachnoid hemorrhage due to a ruptured dissecting aneurysm on the left vertebral artery (VA). Following an occlusion test, we performed proximal occlusion of the left VA with detachable balloons. However, a dissecting aneurysm on the right VA developed three weeks later. After an occlusion test had showed no change in cerebral blood flow, auditory brain stem response, or neurological status, proximal occlusion of the right VA was performed. The patient has returned to normal life without neurological deficits. Bilateral dissecting aneurysms of the VA are quite common, but de novo VA dissecting aneurysms or enlargement of such aneurysms after occlusion of contralateral VA are rare. This case suggests that hemodynamic stress may be a causal factor in the development of VA dissecting aneurysms. Careful pre- and post-operative neuroradiological examination of the contralateral VA are required in patients under-going VA occlusion for dissecting aneurysms.     

Aneurysm of the distal posteroinferior cerebellar artery of extracranial origin: case report

OBJECTIVE AND IMPORTANCE: We describe a very rare case involving a ruptured intracranial aneurysm at the distal posteroinferior cerebellar artery (PICA) branching from the extracranial vertebral artery. CLINICAL PRESENTATION: A 53-year-old woman experienced the sudden onset of a severe occipital headache and vomiting. Computed tomographic scanning revealed subarachnoid and intraventricular hemorrhage. Cerebral angiography of the left vertebral artery demonstrated the left PICA branching from the extracranial segment of the extracranial vertebral artery at the level of C2; a saccular aneurysm arose from the intracranial portion of the distal PICA. INTERVENTION: Via the transcondylar approach, we were able to obtain adequate visualization without retracting important structures. To avoid injury to the anomalous PICA, the aneurysm was clipped. CONCLUSION: Only four other cases of a distal aneurysm of the PICA branching from the extracranial vertebral artery have been reported in the literature. In all cases, the aneurysm originated at the intradural extracranial portion of the PICA. To our knowledge, the case presented here is the first report of a ruptured aneurysm at the level of the intracranial portion of the PICA branching from the extracranial segment of the vertebral artery.     

Treatment of vertebral artery aneurysms with posterior inferior cerebellar artery-posterior inferior cerebellar artery anastomosis combined with parent artery occlusion

BACKGROUND: In patients with aneurysms that involve the origin of the posterior inferior cerebellar artery (PICA) and require occlusion of the vertebral artery (VA), revascularization of the PICA is commonly performed. We present six patients with dissecting VA aneurysms who underwent PICA-PICA anastomosis combined with parent artery occlusion. METHODS: After a lower lateral suboccipital craniectomy and partial resection of the jugular tubercle, anastomoses were performed in a side-to-side fashion at the posterior medullary segment of the PICA. The VA was subsequently occluded by clipping proximal and distal to the aneurysm, and the PICA was occluded by clipping distal to the aneurysm. RESULTS: Postoperative cerebral angiography demonstrated patency of the anastomosis and regression of the aneurysm in five of six patients. The remaining patient experienced hemorrhage from contralateral VA dissection and subsequently died. One patient experienced myopathy of the lower extremities secondary to intraoperative fixed board compression and developed permanent lower extremity muscular weakness. The remaining four cases experienced no new neurologic deficits. CONCLUSION: PICA-PICA anastomosis is a useful procedure for reconstruction of the PICA when parent vessel occlusion or trapping is necessary to exclude a VA aneurysm involving the origin of the PICA.     

Flow reverse therapy for ruptured dissecting aneurysm of basilar trunk: case report

Treatment of ruptured dissecting aneurysm of basilar trunk (BADAN) has been controversial yet. We report a case of ruptured BADAN successfully treated with endovascular occlusion of the bilateral vertebral artery (VA) proximal to posterior inferior cerebellar artery (PICA), allowing retrograde flow via the posterior communicating arteries to basilar artery. A 58-year-old woman who had subarachnoid hemorrhage was treated with endovascular occlusion of the right VA in acute stage after ballon occlusion test (BOT) of the right VA. Because following BOT of the left VA showed conscious level down, left VA could not be occluded. Follow-up angiography after 26 days revealed regrowth of BADAN. So left VA occlusion was tolerable by BOT after 1 month, we performed endovascular occlusion of the left VA proximal to PICA. She discharged with no neurological deficit after 3 months. Postoperative angiograms 3 months after onset showed complete healing of the aneurysm. The follow-up MRA at 19 months showed no recurrence. We discussed the therapeutic strategy of ruptured BADAN. Flow reverse therapy of bilateral VA occlusion by endovascular method for ruptured BADAN is one of the effective therapy.     

Ruptured aneurysm on a double origin of the posterior inferior cerebellar artery: a pathological entity in an anatomical variation. Report of two cases and review of the literature.

The posterior inferior cerebellar artery (PICA) is known to be very variable, and some of its anatomical variations can explain ischemic complications that occur during endovascular treatment of aneurysms. The authors report two cases of anatomical variation of the PICA that they have called its double origin, one of which gave rise to an aneurysm. The first patient was a 36-year-old man who presented with a subarachnoid hemorrhage related to the rupture of a PICA aneurysm. The aneurysm was treated by the endovascular route. Selective and superselective studies showed that the PICA origin was low on the fourth segment of the vertebral artery (VA). The aneurysm was located on an anastomosis between the PICA and a small upper arterial branch originating from the VA. Embolization was performed through the small branch with no problem, but a lateral medullary infarct followed, probably due to occlusion of the perforating vessels. The same anatomical variation was incidentally discovered in the second patient. To the authors' knowledge, neither this anatomical variation of the PICA nor the aneurysm's topography have been previously described angiographically. This highlights the role of angiography in pretreatment evaluation of aneurysms especially when perforating vessels or small accessory branches that are poorly visualized on angiographic studies are concerned, as in the territory of the PICA. Anatomy is sometimes unpredictable, and the surgeon must be very careful when confronted with these variations because they are potentially dangerous for endovascular treatment.     

Vertebral dissecting aneurysm treated with trapping and bilateral posterior inferior cerebellar artery side-to side anastomosis; case report

A case is reported of ruptured dissecting aneurysm of the intracranial vertebral artery (VA) operated on with VA trapping and bilateral posterior inferior cerebellar artery (PICA) side-to-side anastomosis. A 42-year-old male suddenly developed severe headache and vomiting. On admission, 3 hours later, he was in a state of moderate confusion (Japan Coma Scale 3) and had neck stiffness. Computed tomography (CT) revealed diffuse subarachnoid hemorrhage, especially thick in the posterior fossa with right side dominance. Right vertebral angiography disclosed a fusiform dilatation with proximal narrowing of the right VA which originated just proximal to the VA-PICA junction. Lateral suboccipital craniectomy was undertaken with the patient in a left park bench position. Right VA was dilated and discolored black, and right PICA arose from the proximal portion of this aneurysmal dilatation. Since it was impossible to clip the VA distal to the PICA for the proximal clip-occlusion, the VA including the VA-PICA junction was trapped. Considering the risk of developing infarction at the PICA territory, bilateral PICA was anastomosed at their posterior medullary segment in a side-to-side fashion because the occipital artery (OA) had been cut at the skin incision and could not be used for the OA-PICA anastomosis. The postoperative course was benign, but a mild lateral medullary syndrome developed. CT revealed no abnormal low density area and left vertebral angiography demonstrated the patency of the bypass. Thereafter, the deficit subsided gradually and the patient was discharged. He is presently working without neurological deficit.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dissecting aneurysms of the vertebral artery: a management strategy

OBJECT: The authors present a retrospective analysis of their experience in the treatment of vertebral artery (VA) dissecting aneurysms and propose a management strategy for such aneurysms, with special emphasis on the most formidable VA dissecting aneurysms, which involve the origin of the posterior inferior cerebellar artery (PICA). METHODS: Since 1998, 18 patients with VA dissecting aneurysms, 11 of whom presented with subarachnoid hemorrhage (SAH), have been treated by endovascular surgery at the authors' institution. Obliteration of the entire segment of the dissected site with coils (internal trapping) was performed for aneurysms without involvement of the origin of the PICA (12 cases; among these the treatment-related morbidity rate was 16.7%). The treatment strategy applied to PICA-involved VA dissecting aneurysms presenting with SAH (three cases) included proximal occlusion of the parent artery followed by internal trapping of the aneurysm (one case), proximal occlusion of the parent artery followed by occipital artery (OA)-PICA bypass (one case), and two-staged internal trapping of the aneurysm involving double PICAs (one case). For PICA-involved VA dissecting aneurysms that were not associated with SAH at presentation (three cases), OA-PICA bypass was performed and followed by internal trapping of the aneurysm (two cases). In the remaining case in which a fetal-type posterior communicating artery was present, internal trapping was performed following successful balloon test occlusion (BTO). Overall, there was no sign of infarction in the PICA territory, despite complete occlusion of aneurysms involving the PICA. There was no recurrent bleeding or ischemic symptoms during the follow-up periods. The overall treatment-related morbidity rate for the VA dissecting aneurysms involving the PICA was 16.7%. CONCLUSIONS: Dissecting VA aneurysms that do not involve the PICA can be safely treated by internal trapping. For those lesions that do involve the PICA, a decision-making algorithm is advocated to maximize the efficacy of the treatment as well as to minimize the risks of treatment-related morbidity based on BTO.     

Extracranial posterior inferior cerebellar artery aneurysm causing isolated intraventricular hemorrhage: a case report

The authors report the unusual case of an aneurysm arising on an extracranial loop of the left posterior inferior cerebellar artery (PICA). The computed tomographic scan showed an isolated hemorrhage in the lateral ventricles, and the lesion was recognized 1.5 cm below the foramen magnum at the level of the atlas. The literature concerning peripheral PICA aneurysms is reviewed and the clinical and radiological features of these lesions are discussed. A tendency for subarachnoid bleeding from distal PICA aneurysm ruptures to spread into the ventricular system is suggested. The diagnosis of distal PICA aneurysm should also be considered in cases of isolated intraventricular hemorrhage without obvious parenchymal or subarachnoid hemorrhage. The need for four-vessel angiography when studying patients suffering from a subarachnoid hemorrhage is stressed.     

Dissecting vertebral aneurysm with subarachnoid hemorrhage after ischemic onset on the same day: a case report

We report a case of a dissecting vertebral aneurysm with subarachnoid hemorrhage (SAH) after ischemic onset on the same day. A 48-year-old man had abrupt vertigo and nausea. CT & MRI on admission showed no abnormality, but he complained of left hemiparesis after admission. Twelve hours after the ischemic onset he suddenly complained of severe headache and his consciousness deteriorated. The follow-up CT showed diffuse SAH. Cerebral angiography showed occlusion of the right vertebral artery at the origin of the posterior inferior cerebellar artery (PICA) and segmental stenosis of the left vertebral artery at the portion distal to the vertebral PICA junction. We treated the patient conservatively. Four days later, he suddenly fell into a coma, but CT showed no bleeding. Because of this we suspected brain stem ischemia due to deterioration of vertebral dissection. The patient died 8 hours after the ischemic reattack. We report difficulty of treatment of a dissecting vertebral aneurysm with simultaneous ischemia and subarachnoid hemorrhage.     

Aneurysms of the distal posterior inferior cerebellar artery--analysis of 14 aneurysms in 13 cases

Thirteen cases of distal posterior inferior cerebellar artery (PICA) aneurysms are reported here. All the aneurysms were found after a subarachnoid hemorrhage. Dissecting aneurysm, incidentally found unruptured aneurysms, and aneurysms associated with arteriovenous malformation have been eliminated from this study. Characteristics for this type of lesion are a high rate of recurrent hemorrhage and rapid death due to direct compression of the brain stem, which clearly indicates the necessity of early surgery. Attention should be paid to the fact that angiography cannot always reveal aneurysms, especially when they are located in the peripheral PICA. One should also pay attention to multiple lesions and rapid growing acute subdural hematoma as initial findings for ruptured distal PICA aneurysm. Prognostic factors for these lesions are, vasospasm, especially when the aneurysm is located proximally in the PICA, and direct compression of the brain stem due to intraventricular hemorrhage when the aneurysm is located distally. It has been suggested that the pathogenesis of this lesion could be hemodynamic stress or embryogenesis. The shape and anomalous arterial structures of the 14 aneurysms presented here tend to agree with this suggestion. Our results suggest that the pathogenesis is hemodynamic stress that had developed due to embryological and/or arteriosclerotic factors.     

A case of a persistent primitive proatlantal intersegmental artery with a ruptured basilar bifurcation aneurysm

A case of persistent primitive proatlantal intersegmental artery (PPPIA) associated with a ruptured basilar bifurcation aneurysm was reported. A 44-year-old male with sudden headache was admitted to our hospital. CT scan revealed subarachnoid hemorrhage. Cerebral angiography revealed anomalous anastomosis between the internal carotid artery and the vertebral artery at the proatlantal region. This anastomosis branched off from the left internal carotid artery at the C4 level and joined the horizontal portion of the left vertebral artery. It was thought to be PPPIA. Angiography also revealed an aneurysm of the basilar bifurcation which was responsible for the patient's subarachnoid hemorrhage. The aneurysm was successfully treated by endovascular embolization with Guglielmi detachable coils in an acute stage, and resulted in good outcome. PPPIA with basilar bifurcation aneurysm has not been presented or reported in the literature to date. To our knowledge, this is the first report of such an association of vascular anomalies. The frequency of PPPIA combined with the intracranial aneurysm is relatively high, whereas the occurrence of PPPIA is extremely rare. Therefore, it was suggested that some congenital and/or hemodynamic factors changed by PPPIA may affect the pathogenesis of intracranial aneurysms.     

Vertebrobasilar artery dissection presenting with simultaneous subarachnoid hemorrhage and brain stem infarction: case report

BACKGROUND: Intracranial dissecting aneurysms have been associated with subarachnoid hemorrhage (SAH) or cerebral ischemia. We encountered a patient presenting with simultaneous subarachnoid hemorrhage and brainstem infarction caused by a dissecting aneurysm of the vertebrobasilar artery, which was diagnosed by magnetic resonance imaging (MRI) but did not show abnormal findings on cerebral angiography. CASE DESCRIPTION: A 55-year-old man had sudden onset of headache and left abducens palsy. Computed tomography revealed a subarachnoid hemorrhage localized in the left prepontine cistern and the left cerebellomedullary fissure. Cerebral angiography showed neither a saccular aneurysm nor fusiform dilatation causing the subarachnoid hemorrhage. MRI demonstrated a small infarction in the left dorsal pons, and an intramural hematoma of the left vertebral artery and lower basilar artery. CONCLUSION: This is a rare case of a vertebrobasilar dissecting aneurysm that simultaneously caused both SAH and brain stem infarction. MRI should be performed in the acute phase of SAH of unknown origin to determine the possible coexistence of a dissecting aneurysm, as occurred in this case.     

Multiple aneurysms of the distal posterior inferior cerebellar artery with recurrent hemorrhage undetectable on preoperative neuroradiological findings: case report

We report a rare case of multiple aneurysms of the distal posterior inferior cerebellar artery (PICA) associated with recurrent hemorrhage undetectable on preoperative neuroradiological findings. A 68-year-old woman was admitted to our hospital in April, 2003 because of a sudden onset of headache, back neck pain and nausea. CT scan at the time of admission showed a hematoma in the 4th & 3rd ventricles, and a mild subarachnoid hemorrhage (SAH) in the basal, right ambient & quadrigeminal cisterns. She had had a similar history of previous intraventricular hemorrhage and SAH in October, 2001. Three-dimensional CT angiograms and left vertebral angiograms performed at that time revealed an irregular vascular lesion at the tonsillomedullary segment (TMS) of the left PICA. However, the final diagnosis was unclear. Left vertebral angiograms at the time of the 2003 admission revealed an irregular vascular lesion in the same region more clearly and the size of aneurysmal dilatations had increased considerably. So, preoperative diagnosis of an irregular vascular lesion at the TMS of the left PICA (distal PICA aneurysm was not ruled out) was based on the above neuroradiological findings. The patient was surgically treated through the suboccipital approach. The TMS of the left PICA had made a difficulty loop formation was observed. Five distinct aneurysma were found on the TMS of the left PICA. To prevent bleeding, the ruptured aneurysm & three unruptured aneurysms were clipped and the residual unruptured one was wrapped with Bemsheets. Postoperative left vertebral angiograms demonstrated neither clipped aneurysms nor occlusive findings at the TMS of the PICA. The patency of the PICA was preserved. The postoperative course was uneventful and the patient was discharged without new neurological deficits. There has been no rebleeding during the one year since surgery. The 23 reported cases of multiple aneurysms of the distal PICA including our case were reviewed and their neuroradiological and clinical features are discussed.     

Vertebrobasilar junction aneurysms associated with fenestration: experience of five cases treated with Guglielmi detachable coils

BACKGROUND: Fenestration of vertebrobasilar junction is a rare congenital anomaly and often associated with aneurysm formation. We describe five cases of vertebrobasilar junction aneurysms in four patients associated with fenestration, which were treated with endovascular coil occlusion using Guglielmi detachable coils (GDCs). The importance of preoperative computed tomography (CT) angiography to understand the complex anatomy of fenestration and aneurysm is emphasized. CASE REPORTS: Three patients presented with subarachnoid hemorrhage and one patient presented with headache only. Among 3 patients with subarachnoid hemorrhage, 1 patient was referred for endovascular coil occlusion after clipping of ruptured distal ACA aneurysm. A six-French guiding catheter was placed in the left vertebral artery via right femoral artery, except for 1 patient who had two vertebrobasilar junction aneurysms with complex anatomic relationship, accessed bilaterally. Five vertebrobasilar junction aneurysms with fenestration were treated with endovascular coil occlusion using GDCs. Postoperative angiography demonstrated successful occlusion of aneurysmal sac with preservation of basilar artery. CONCLUSIONS: Vertebrobasilar junction aneurysms are frequently associated with fenestrations. In addition to vertebral angiography on both sides, CT angiography may be a valuable tool for better understanding of complex anatomy of aneurysms associated with fenestration. The surgically difficult aneurysms such as vertebrobasilar junction aneurysm with fenestration can be successfully treated with GDCs.