Classification and treatment of vertebral dissecting aneurysm

Reconstructive vs Deconstructive Endovascular Approach to Intradural Vertebral Artery Aneurysms: A Multicenter Cohort Study

BACKGROUND

Parent vessel sacrifice (PVS) has been a traditional way of treating complex aneurysms of the intradural vertebral artery (VA). Flow diversion (FD) has emerged as an alternative reconstructive option.

OBJECTIVE

To compare the long-term clinical and radiographic outcomes of intradural VA aneurysms following PVS or FD.

METHODS

We retrospectively reviewed and evaluated 43 consecutive patients between 2009 and 2018 with ruptured and unruptured intradural VA aneurysms treated by PVS or FD. Medical records including clinical and radiological details were reviewed.

RESULTS

A total of 43 intradural VA aneurysms were treated during this period. In the 14 PVS patients, the mean follow-up was 19.5 mo, and 71.4% of cases achieved modified Rankin scale (mRS) ≤2 at the last follow-up. A total of 86.5% of cases achieved complete occlusion. There was a 14.3% (2 cases) mortality rate, 14.3% (2 cases) postoperative ischemic complication rate, and 0% postoperative hemorrhaging rate. Retreatment was required in 1 case (7.1%). In the 29 FD patients, the mean follow-up was 21.8 mo, and 89.7% of cases achieved mRS ≤2 at the final follow-up. There was a 3.2% (1 case) mortality rate, 19.4% (6 cases) of postoperative ischemic complications, and 6.5% (2 cases) of postoperative hemorrhagic complications. Complete occlusion was seen in 86.5% patients. No cases required retreatment. Mortality and complication rates were not significantly different between PVS and PED (Pipeline Embolization Device) groups.

CONCLUSION

PVS was associated with comparable intraprocedural complications for VA aneurysms as compared to FD in the largest multicenter study to date. Both procedures have good long-term clinical and radiological outcomes.

Blind-Alley Formation and Occipital Artery-Posterior Inferior Cerebellar Artery Bypass for the Treatment of Unclippable Vertebral Artery Aneurysms with Posterior Inferior Cerebellar Artery Involvement

BACKGROUND AND IMPORTANCE

Unclippable vertebral artery aneurysms (UVAs) are difficult to treat with direct clipping, especially in cases involving the origin of the posterior inferior cerebellar artery (PICA). Bypass with trapping is the common procedure used for these conditions. The authors used the blind-alley formation technique, which is a simpler method than trapping and can avoid some complications.

OBJECTIVES

To report 7 cases of UVA with PICA involvement treated with blind-alley formation and occipital artery (OA)-PICA bypass as well as their surgical outcomes and complications and to describe the operative techniques.

RESULTS

Seven patients with UVA and PICA involvement underwent OA-PICA bypass and blind-alley formation (occlusions of the PICA origin and vertebral artery proximal to the aneurysm). Vertebral artery dissecting aneurysms and fusiform atherosclerotic vertebral artery aneurysms were detected in 6 patients and 1 patient, respectively. All patients presented with subarachnoid hemorrhage, and 71.4% of them were classified into the poor-grade group. Good bypass patency and complete aneurysm obliteration were achieved in all cases. Six aneurysms (85.7%) were completely obliterated according to computed tomography angiography performed immediately postoperatively. Another aneurysm was 50% and 100% thrombosed immediately and at 7 days after the operation, respectively. Surgical complications were found in 1 patient (14.3%) who had postoperative diparesis with dysphagia. Three patients (42.9%) achieved a Glasgow Outcome Score of 4 or 5 one month after the operation.

CONCLUSIONS

Blind-alley formation and OA-PICA bypass are simple, safe, and effective for the treatment of patients with UVA with PICA involvement.

Surgical Management and Outcomes of Aneurysms of Posterior Inferior Cerebellar Artery: Location-Based Approaches with Review of Literature

Background  Posterior inferior cerebellar artery (PICA) is a tortuous, variable, and uncommon site for aneurysms. Surgical management of PICA aneurysms involves careful selection of approach based on the location of the aneurysm and meticulous dissection of the neurovascular structures and perforators.

Materials and Methods  We did a retrospective review of all the PICA aneurysms operated at our institute in the past 10 years along with the site, presentation, and approach used for the same. Preoperative World Federation of Neurosurgical Society scores and follow-up modified Rankin scores (mRS) were also evaluated. During the same period, data for intervention cases of PICA aneurysm were also collected with follow-ups for a comparative analysis.

Results  A total of 20 patients with 21 PICA aneurysms were reviewed. All the reviewed cases presented with subarachnoid hemorrhage, and the most common location was the lateral medullary segment and vertebral artery (VA)–PICA junction. Midline approaches were used for distal PICA cases, with far-lateral approach reserved for anterior medullary/VA–PICA junction. No lower cranial nerve palsies were recorded at follow-up. Four cases needed cerebrospinal fluid diversion and two developed cerebellar infarcts. All cases were mRS 0 to 2 at follow-up.

Conclusion  Our series compares well with some of the larger surgical series of PICA aneurysms. This may be due to early referral patterns and early surgery (<24 hours) policy at our institution. Anatomical knowledge of PICA anatomy and sound perioperative management are keys to good outcomes in these cases.

Endovascular coil oclusion of spontaneous ruptured vertebral artery dissecting aneurysm

Spontaneous dissecting aneurysm of vertebral artery is known as a rare pathological condition causing a subarachnoid hemorrhage in the posterior circulation. The treatment of ruptured vertebral artery dissecting aneurysms is still an important subject of debates in the literature. We present a particular case of ruptured vertebral artery dissecting aneurysms that was treated by only endovascular Guglielmi detachable coils occlusion. A brief review of technical possibilities of treatment of these types of vascular lesions, with their advantages and disadvantages are discussed.

State-of-art in surgical treatment of dissecting posterior circulation intracranial aneurysms

Vertebrobasilar (VB) intracranial dissecting aneurysms (IDAs) pose difficult therapeutic issues and are especially among the most difficult to manage surgically. There are, however, some cases where selective aneurysm obliteration by endovascular approach is impossible or is associated with an unacceptable risk of morbidity. This is particularly true when the aneurysm is dissecting, giant, or has a large neck. In such cases, surgical treatment may be the only alternative. Optimal management of these lesions is therefore challenging and treatment decisions have to be made on a case-by-case basis. Ideal treatment should be a complete surgical excision of the lesion; however, this procedure might only be possible after distal and proximal vessel wall occlusion which might not be tolerated by the patient depending on the location of the aneurysm. Therefore, formulation of recommendations concerning the surgical strategy remains still difficult due to inconsistency of surgical outcomes. The literature describing surgical strategy of VB IDAs is varying in quality and content, and many studies deal with only a few patients. In the presented review, the authors summarize the current knowledge on the incidence, pathogenesis, clinical presentation, and diagnostic procedures with special emphasis on surgical treatment of IDAs in posterior circulation.

Therapeutic Progress in Treating Vertebral Dissecting Aneurysms Involving the Posterior Inferior Cerebellar Artery

Among the variations of vertebral artery dissecting aneurysms (VDAs), VDAs involving the posterior inferior cerebellar artery (PICA), especially ruptured and high-risk unruptured aneurysms, are the most difficult to treat. Because the PICA is an important structure, serious symptoms may occur after its occlusion. Retained PICAs are prone to re-bleeding because VDAs are difficult to completely occlude. There is therefore confusion regarding the appropriate treatment for VDAs involving the PICA. Here, we used the PubMed database to review recent research concerning VDAs that involve the PICA, and we found that treatments for VDAs involving the PICA include (i) endovascular treatment involving the reconstruction of blood vessels and blood flow, (ii) occluding the aneurysm using an internal coil trapping or an assisted bypass, (iii) inducing reversed blood flow by occluding the proximal VDA or forming an assisted bypass, or (iv) the reconstruction of blood flow via a craniotomy. Although the above methods effectively treat VDAs involving the PICA, each method is associated with both a high degree of risk and specific advantages and disadvantages. The core problem when treating VDAs involving the PICA is to retain the PICA while occluding the aneurysm. Therefore, the method is generally selected on a case-by-case basis according to the characteristics of the aneurysm. In this study, we summarize the various current methods that are used to treat VDAs involving the PICA and provide schematic diagrams as our conclusion. Because there is no special field of research concerning VDAs involving the PICA, these cases are hidden within many multiple-cases studies. Therefore, this study does not review all relevant documents and may have some limitations. Thus, we have focused on the mainstream treatments for VDAs that involve the PICA.

Discrepancy between preoperative imaging and postoperative pathological finding of ruptured intracranial dissecting aneurysm, and its surgical treatment: case report

The choice of therapeutic strategy for intracranial dissecting aneurysm is often based on radiographic features, including characteristic geometry (e.g., irregular stenosis, segmental stenosis, aneurysm formation [pearl-and-string sign]), irregular fusiform or aneurysmal dilation, double lumen, and tapering occlusion. However, there is often a discrepancy between preoperative radiographic data and actual dissecting length. The present report describes three cases in which there was a discrepancy between preoperative radiographic data and actual dissecting length in patients undergoing direct trapping with or without revascularization. All three cases experienced good outcomes, but these cases underscore the fact that open surgery is a good option for management of ruptured intracranial dissecting aneurysms for determination of the rupture point, dissecting length, and the relationship between dissecting area and small arteries arising from the associated vessel.

Endovascular repair of a double-lumen dissecting aneurysm

Treating dissections and dissecting aneurysms requires maintenance of flow through the true lumen and exclusion of the false lumen from the circulation. A dissecting aneurysm of the vertebral artery presented with both a true and false lumen within the aneurysmal sac. Stenting of the true lumen followed by coil embolization of both lumens was performed. Management options and decision-making are discussed for this unique situation.

Endovascular repair of a double-lumen dissecting aneurysm

Treating dissections and dissecting aneurysms requires maintenance of flow through the true lumen and exclusion of the false lumen from the circulation. A dissecting aneurysm of the vertebral artery presented with both a true and false lumen within the aneurysmal sac. Stenting of the true lumen followed by coil embolization of both lumens was performed. Management options and decision-making are discussed for this unique situation.

Intracranial vertebral artery dissections: evolving perspectives

Intracranial vertebral artery dissection (VAD) represents the underlying etiology in a significant percentage of posterior circulation ischemic strokes and subarachnoid hemorrhages. These lesions are particularly challenging in their diagnosis, management, and in the prediction of long-term outcome. Advances in the understanding of underlying processes leading to dissection, as well as the evolution of modern imaging techniques are discussed. The data pertaining to medical management of intracranial VADs, with emphasis on anticoagulants and antiplatelet agents, is reviewed. Surgical intervention is discussed, including, the selection of operative candidates, open and endovascular procedures, and potential complications. The evolution of endovascular technology and techniques is highlighted.

Long-term follow-up of ruptured intracranial aneurysms treated by microsurgical wrapping with autologous muscle

The purpose of this study is to describe our series of nine unclippable and uncoilable ruptured aneurysms in eight patients treated by microsurgical wrapping with autologous muscle. Records were retrospectively reviewed for rebleeding rate, morbidity and mortality, changes in size or the aneurysm's configurations, and inflammatory reaction. We conducted a Medline search in the post-microsurgical era, excluding patients in whom wrapping was part of the aneurysm treatment in combination with clipping or coiling. The surgically related morbidity was 12.5%. Global mortality rate was 25% due to vasospasm (one case) and rebleeding (one case). Six patients are still alive. Rebleeding rate was 14.3% within 6 months; then, it was zero. Glasgow outcome scale (GOS) score at discharge was 1 and 4 in one patient, respectively, and 5 in the remaining six. Mean clinical follow-up was 126 months. GOS at last follow-up was 4 and 5 in 50% of patients, respectively. Mean mRS score was 0.8 at 2 months, and 2.4 at 12 months. Follow-up MR demonstrated persistence of the aneurysm's sac, without changes in size and configuration. Patients did not describe or exhibit symptoms attributable to complications inherent to the use of muscle. Microsurgical muscle-wrapping of ruptured intracranial aneurysm is safe, is associated with a low rate of acute and delayed postoperative complications and rebleeding, and could be a valid alternative for unclippable and non-amenable to endovascular procedure ruptured aneurysms.

Spontaneous intradural vertebral artery dissection: a single-center experience and review of the literature

OBJECTIVES

To define the natural history of spontaneous intracranial vertebral artery dissections (VADs) and to review current treatment strategies.

MATERIAL AND METHODS

We searched the MEDLINE database for all existing English and French literature on VADs through January 2008. Keywords employed were intradural/intracranial vertebral artery dissection, vertebral artery dissection, and vertebral artery dissection treatment. We also reviewed our series of patients with spontaneous VAD treated in the past 5 years. Data were collected, categorized, and analyzed.

RESULTS

In our sample of 457 patients, men were more frequently affected than women, and the mean age was 51.8 years. The majority of patients (79%) presented with subarachnoid hemorrhage (SAH). We experienced a high incidence (37%) of recurrent SAH, particularly within the first 24 hours after SAH first occurred. Angiographic fusiform dilatation and pearl-and-string lesions were the most common finding. Patients who presented with SAH fared worse than those who presented with ischemia.

CONCLUSIONS

Due to a high rate of recurrent bleeding, we concluded that early treatment by either surgical or endovascular route is indicated in patients who present with SAH secondary to spontaneous intradural VADs. Treatment decisions should take into account the site and type of dissection, vertebral artery dominance, and involvement of posterior inferior cerebellar artery.

A study of vertebrobasilar artery dissection with subarachnoid hemorrhage

We retrospectively studied clinical characteristics of 368 patients with cerebral artery dissections who were diagnosed in 172 Japanese hospitals. Of these patients, 130 (35%) presented with subarachnoid hemorrhage, 217 (59%) with cerebral infarctions, and 21 (6%) with transient ischemic attacks. We analyzed 109 (84%) subarachnoid hemorrhage cases caused by vertebrobasilar artery dissection to evaluate conservative and surgical treatment from the viewpoint of postoperative rerupture and infarction.Subsequent ruptures were observed in 14% of the 21 cases with nonsurgical treatment. For the preventive purpose of rerupture, 88 patients received surgical interventions: 68 trappings, 13 proximal occlusions, 6 aneurysmal sac occlusions and 1 stenting. Rerupture was experienced in 33% of the aneurysmal sac occlusion patients while not occurring in the other three surgical interventions. In the group without vascular anastomosis, postoperative cerebral infarction was observed in 25% of the trapping, none of the proximal occlusion and 33% of the aneurysmal sac occlusion cases.In this study, aneurysmal sac occlusion treatments were more frequently complicated by rerupture or cerebral infarction postoperatively than the other treatment methods. It was difficult to determine which surgical treatment can achieve better surgical outcome among the proximal occlusion and trapping with or without vascular anastomosis.

Vertebral artery dissection: natural history, clinical features and therapeutic considerations

When a tear occurs in one of the major cervicocerebral arteries and allows blood to enter the wall of the artery and split its layers, the result is either stenosis or aneurysmal dilatation of the vessel. Vertebral artery dissection (VAD) is an infrequent occurrence but is a leading cause of stroke in young and otherwise healthy patients. This article discusses recent developments in understanding of the epidemiology and pathogenesis of VAD and the various clinical manifestations, methods of diagnosis, and approaches to treatment.

Endovascular treatment of huge dissecting aneurysms involving the basilar artery. Experience and lessons from two cases

SUMMARY

Dissecting aneurysms involving the basilar artery (BA) are lesions with significant morbidity and mortality. Their management is controversial and often difficult. There is no generally approved strategy. Two cases of huge dissections involving the BA presented with subarachnoid hemorrhage in one case and mass effect in both cases. The dissection of case 1 involved the upper two thirds of the BA distal to the anterior inferior cerebellar arteries (AICA). Another dissection of case 2 involved the bilateral vertebral arteries (VA) distal to bilateral PICA and extended to upper third of the BA. After making a basket with coils inside the pseudoaneursym, proximal dissection was totally occluded in case 1. Dissection on the bilateral VA distal to the bilateral PICA and proximal BA was occluded in case 2 with a small residual dissection on the left VA. Case 1 had an excellent recovery with a durable image and clinical result. But recanalization and regrowth occurred in case 2, which might have originated from the residual dissection on the left VA, induced acute mass effect and sudden coma six weeks after the initial treatment. The residual and regrown dissection had to be occluded in a second intervention. The patient died two days later. BA occlusion is safe and efficient for dissections involving the BA as in our case and the literature. Proximal occlusion might be enough for huge and long lesions like ours. It seems that completely dense packing of proximal dissection is the key point to prevent recanalization.

Hemorrhagic cerebral dissecting aneurysms: surgical treatments and results

INTRODUCTION

Cerebral dissecting aneurysms are an increasingly recognized etiology of subarachnoid hemorrhage SAH and cerebral stroke. Hemorrhagic dissecting aneurysms of the anterior circulation have been considered to be somewhat different to those of the posterior circulation not only in terms of their pathophysiology, but also in terms of their management. Herewith our series of hemorrhagic dissecting aneurysms of the internal carotid artery ICA, vertebral artery VA, basilar artery BA and some of those of distal cerebral arteries is presented and compared to the series reported in the literature. Therapeutic consideration in the light of our experiences emphasizing the significance of aneurysm entrapment in combination with bypass surgery is presented.

MATERIAL AND METHODS

During the last 13 years over 1000 patients with cerebral aneurysms were treated surgically in our department. Hemorrhagic dissecting aneurysms were diagnosed in 26 patients. Diagnosis was based on neuroradiological findings as well as intraoperative findings. All patients underwent surgical intervention. Clinical findings of these patients were analysed retrospectively. Follow-up outcomes were evaluated according to the Glasgow Outcome Scale GOS at 3 months after treatments.

RESULTS

Location of 26 dissecting aneurysms was: ICA 11 cases (42%), VA 9 cases (35%), BA 3 cases, MCA 2 cases and PCA (P1 segment) one case. Primary surgical treatments were performed on day 3.7 of SAH on average. Clinical manifestation of dissecting aneurysms of the ICA and their outcome was more severe compared with those of the VA (p < 0.01): WNFS grade 3.1 vs 2.4 and GOS score 3.4 vs 4.3. As a conventional neck clipping procedure was problematic or impossible (aneurysm recurrence after clipping, premature rupture at the time of exposure or clipping), entrapment (or proximal ligation) plus EC-IC bypass procedure was the most frequent final definitive method of surgical treatment (9/26 35%: ICA 6/11, VA 1/9 and MCA 2/2) followed by proximal ligation or trapping only 7/26, neck clipping 7/26 and coating 4/26.

CONCLUSIONS

Hemorrhagic dissecting aneurysms still remain problematic in their diagnosis and treatment. One has to be aware of the diagnostic possibility of dissecting aneurysms as an etiology of SAH. Neurosurgeons have to be prepared to be able to manage complex surgical situations also by the use of EC-IC bypass, as its combination with entrapment procedure can be the final treatment of choice. Less invasive endovascular technique is in evolution but its availability and superiority are still to be settled.

Spontaneous dissecting aneurysm of the intracranial vertebral artery: management strategies

PURPOSE

Pathogenesis and treatment of spontaneous dissecting aneurysm of the intracranial vertebral artery (VA) remain controversial. This study was designed to provide management strategies and to improve management outcome in patients with these aneurysms.

MATERIALS AND METHODS

Among a total of 1,990 patients treated for intracranial aneurysms from February 1992 to June 2005, 28 patients (1.4%) were treated either by surgery (8 patients) or neurointervention (20 patients) for spontaneous dissecting aneurysms of the intracranial VA. Twenty-two patients had ruptured aneurysms. We analyzed indications of surgery or neurointervention for each case, and assessed the management outcome at a 6-month follow-up.

RESULTS

For selection of therapeutic options, patients were initially evaluated as possible candidates for neurointervention using the following criteria: 1) poor clinical grade; 2) advanced age; 3) medical illness; 4) unruptured aneurysm; 5) equal or larger opposite VA; 6) anticipated surgical difficulty due to a deep location of the VA-posterior inferior cerebellar artery (PICA) junction. Surgery was considered for patients with: 1) high-risk aneurysms (large or irregular shaped); 2) smaller opposite VA; 3) failed neurointervention; or 4) dissection involving the PICA. Management outcomes were favorable in 25 patients (89.3%). Causes of unfavorable outcome in the remaining 3 patients were the initial insult in 2 patients, and medical complications in one patient.

CONCLUSION

Ruptured aneurysms must be treated to prevent rebleeding. For unruptured aneurysms, follow-up angiography would be necessary to detect growth of the aneurysm. Treatment modality should be selected according to the clinical characteristics of each patient and close collaboration between neurosurgeons and neurointerventionists is essential.

Aneurisma dissecante de artéria vertebral intracraniana fenestrada submetido ao tratamento endovascular: relato de caso

Aneurismas dissecantes da artéria vertebral em seu segmento intracraniano são lesões pouco comuns, principalmente quando associadas a hemorragia subaracnóidea, sendo também raras as fenestrações da artéria vertebral. Apresentam elevada morbidade e mortalidade, com elevado índice de ressangramento e dificuldade de abordagem cirúrgica. Apresentamos o caso de um homem de 19 anos, o qual foi vitima de agressão física em região occipto-cervical, apresentando hemorragia subaracnóidea e aneurisma dissecante na artéria vertebral direita, a qual era fenestrada, sendo submetido ao tratamento endovascular. Realizamos revisão da literatura sobre o assunto, sendo colocado o tratamento endovascular como uma opção terapêutica para estes casos.

Treatment of hemorrhagic intracranial dissections

OBJECTIVE

To analyze the treatment options in hemorrhagic intracranial dissections.

METHODS

This study involved a retrospective review of 27 patients with 29 dissections treated during a 16-year period, mainly by endovascular treatment (EVT).

RESULTS

EVT was performed in the acute stage in 12 of the 29 dissections, and occlusion was performed using coils at the dissection site in six dissections and with proximal balloon occlusion in six dissections. Wrapping was performed in one case. In the remaining 16 dissections, which were not treated, mainly for anatomic reasons, three patients died, one from rebleeding. Angiographic follow-up performed in the 13 surviving patients demonstrated an initially misdiagnosed lesion in one and worsening lesions in five that led to delayed EVT in five and surgical clipping in one. One of these dissections, which was located on a dominant vertebral artery, was treated after subsequent rupture using a stent and coils to preserve the patency of the parent vessel. Four ischemic complications related to EVT resulted in a moderate disability in two patients. No rebleeding occurred after EVT, but one patient died because of a poor initial clinical status; the other patients improved. In the 10 patients treated conservatively, four died, three from a poor initial clinical status and one from rebleeding, and six patients had a good clinical outcome. Of the 27 patients, three had rebleeding and one died as a result of that rebleeding. Seventeen patients (63%) had a good recovery, six (22%) had a moderate disability, and four (15%) died.

CONCLUSION

EVT provides effective protection against rebleeding. When possible, occlusion with coils at the dissection site is the current method of choice. Another option is parent artery occlusion with balloons, and the use of a stent may preserve vessel permeability in specific cases.

Arterial reconstruction by direct surgical clipping of a basilar artery dissecting aneurysm after failed vertebral artery occlusion: technical case report and literature review

OBJECTIVE AND IMPORTANCE

Dissecting aneurysms of the basilar artery are rare lesions with significant morbidity and mortality. Their management is controversial and often difficult. Although the rebleeding rate is high, clip reconstruction carries prohibitive risk because of the damage to the parent vessel induced by the dissection and the lack of tissue to gather. An enlarging pseudoaneurysm in the chronic phase, however, may have sufficient tissue for clip reconstruction. We present a case in which this strategy was used successfully.

CLINICAL PRESENTATION

A 45-year-old woman presented 3 months after an initial presentation with a subarachnoid hemorrhage from a dissecting aneurysm of the basilar trunk at an outside institution. The aneurysm had grown compared with previous angiograms.

INTERVENTION

The dominant vertebral artery was sacrificed. Despite this, the aneurysm continued to enlarge. Given the progressive enlargement of the aneurysm, the decision was made to proceed with arterial reconstruction by direct surgical clipping of the saccular component of the dissecting aneurysm. The patient made an excellent recovery with a durable result.

CONCLUSION

Although clipping an intracranial pseudoaneurysm in the acute phase may carry a prohibitive risk, clipping such an aneurysm in the chronic phase may occasionally be warranted. To our knowledge, this is the first case reported in the literature in which direct surgical clipping was used as the primary mode of treatment for a basilar artery dissecting aneurysm that enlarged despite occlusion of the dominant vertebral artery. We review the literature on this rare pathological entity and discuss our management strategy.

The use of CT-angiography for monitoring thrombus formation after balloon occlusion of a dissecting vertebral artery pseudoaneurysm

We present a 49-year-old man with a subarachnoid haemorrhage from a dissecting vertebral artery (VA) pseudoaneurysm treated with a proximal balloon occlusion. The clinical course was complicated by the sudden appearance of a lateral medullary syndrome (Wallenberg), which completely resolved after anticoagulant therapy. During this course, CT-angiography (CTA) enabled monitoring of both the progression and partial resolution of the thrombus in the occluded VA. An anatomical variant of a perforating artery originating from the VA proximal to the posterior inferior cerebral artery (PICA) was subsequently demonstrated, explaining the ischemic event. The value of CTA in clinical management is discussed. The prophylactic use of anticoagulant therapy especially in the case of a perforating artery to the lateral medulla originating proximally to the PICA, is suggested.

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.

[Subarachnoid hemorrhage secondary to dissecting aneurysms of the vertebral artery. Description of 2 cases and review of the literature]

OBJECTIVES AND INTRODUCTION: The pathogenesis and natural history of intracranial vertebral artery dissection remain uncertain up to now due in part to its relative rarity. In this article we review the state of the art of this process and remark the good outcome obtained with embolization using Guglielmi detachable coiling (GDC).

METHODS

Two cases with subarachnoid hemorrhage secondary to rupture of a vertebral dissection aneurysms are described. The first patient initially suffered brain stem infarction, followed by a subarachnoid hemorrhage a year later. The second patient who had a severe subarachnoid hemorrhage with two early rebleedings was successfully treated with embolization using GDC.

CONCLUSIONS

Subarachnoid hemorrhage due to rupture of vertebral dissecting aneurysm is a relatively unknown disease with some important aspects that should be known. The high incidence of early rebleeding (up to 60%), makes early diagnosis and treatment important goals. Classically the preferred treatment has been proximal vertebral artery occlusion. However, the recent introduction of embolization with GDC has made possible the occlusion of the dissection with very good final outcome.

Intracranial vertebral artery dissection presenting as subarachnoid hemorrhage: successful endovascular treatment

INTRODUCTION

Intracranial vertebral artery dissection is a rare condition which may present as subarachnoid hemorrhage. In this situation, treatment is controversial.

CASE REPORT

A case of intracranial right vertebral artery dissection in a 55-year-old woman presenting with subarachnoid hemorrhage is reported. The patient underwent therapeutic occlusion of the dissected artery through microcatheterization using pushing detachable platinum microcoils and had a good outcome. At this moment, the patient has a normal neurologic examination and a control digital subtraction angiography 1 year after the procedure showed an occluded right vertebral artery at V3; there was retrograde flow in the right intracranial vertebral artery up to the origin of a meningeal branch; the artery was thin and had mural irregularities, without any evidence of aneurismatic dilatation.

DISCUSSION

We review the literature and discuss the role of endovascular therapy and other therapeutic options in the treatment of this condition.

Spontaneous occlusion of ruptured vertebral artery dissection at the extradural fenestration associated with extradural origin of the posterior inferior cerebellar artery--case report

A 69-year-old female suffered from sudden onset of severe headache. Computed tomography showed subarachnoid hemorrhage primarily located in the posterior fossa. Initial angiography demonstrated a fenestration of the vertebral artery and an extracranial origin of the posterior inferior cerebellar artery. However, no bleeding points could be clearly detected. The operative findings revealed a massive clot in subarachnoid space, but no bleeding point. Serial angiography demonstrated dissection in one of the limbs of the fenestrated vertebral artery on the 25th day after the onset. On the 100th day, the lesion was spontaneously occluded. The patient is presently doing well at 8 years after surgery.