Intracranial dissecting aneurysms of the posterior circulation. Report of six cases and review of the literature

Simultaneous intracranial and extracranial vertebral artery dissections: a case report

Vertebral artery dissection can occur in intracranial or extracranial vertebral arteries. However, the simultaneous dissection of both intracranial and extracranial vertebral arteries is extremely rare. We describe a 45-year-old man with simultaneous intracranial and extracranial vertebral artery dissections in separate sites. The patient visited a neurosurgical clinic because of headache; he was diagnosed with right vertebral artery dissection and referred to our hospital. Magnetic resonance imaging showed an intramural hematoma and mild dilation of the external lumen in the right vertebral artery distal to the posterior inferior cerebellar artery. Magnetic resonance angiography revealed poor delineation of the entire right vertebral artery, including the proximal portion from the posterior inferior cerebellar artery. Computed tomography angiography revealed right extracranial vertebral artery dissection. Careful imaging assessment is thus important for identifying simultaneous intracranial and extracranial vertebral artery dissections.

Spectrum of Posterior Cerebral Artery Dissection: A Retrospective Observational Study and a Critical Review

Background and Aims

Intracranial arterial dissections commonly involve the vertebrobasilar system leading to subarachnoid hemorrhage (SAH) or cerebral infarction attributable to a dissecting aneurysm of the vessel or occlusion of the lumen depending on the depth of dissection. However, isolated posterior cerebral artery dissections (PCADs) are rare and sparsely reported in the literature.

Methodology

A retrospective multicentric observational study was carried out after collecting data from 14 patients admitted with PCAD in three hospitals of Kolkata, Jaipur, and Patna within the period of July 2021 to June 2022.

Results

The median age of the population was 48.5 years, and 64.28% were females. SAH was the most common presentation with dissecting aneurysms in all patients barring one, who presented with a left occipital infarct consequent to ipsilateral PCAD. Among the 14 patients, three patients denied endovascular intervention and were lost to follow-up; one patient with an occipital infarct and another patient with a dissecting left P3 aneurysm, which underwent spontaneous thrombosis, were managed conservatively. Among the nine patients scheduled for endovascular coiling, one patient succumbed before intervention and one patient succumbed to sepsis in the postoperative period. A complete recovery was noted in six patients, whereas residual neurodeficits were present in three patients. Among the six patients who had an uneventful recovery at the end of 3 months, five patients had an endovascular intervention.

Conclusion

PCAD may present with large-scale neurodeficits and is associated with high morbidity and mortality, hence necessitating prompt management. Conservative management is preferable for consequent infarcts, whereas endovascular management is desirable in cases of dissecting aneurysms, which usually tend to have a favorable outcome if intervened early.

Posterior cerebral artery dissection after excessive caffeine consumption in a teenager

Arterial ischemic stroke is a rare but significant cause of neurological deficits in childhood. Even though there is a variety of risk factors, identifying the etiology can sometimes be a hard diagnostic challenge. Arteriopathies in general, and more specifically, arterial dissection is one of the uncommon pathologies that can cause incidents of pediatric stroke. We report a rare case of a young adolescent with posterior cerebral artery dissection after excessive consumption of caffeine, contained in energy drinks, only hours before the onset of neurological symptoms. A complete neuroimaging evaluation (MRI, intracranial US and digital subtraction angiography) at the admission and during the follow-ups supported the diagnosis of arterial dissection possibly caused by caffeine overconsumption.

Treatment of intracranial vertebral artery dissecting aneurysms involving the posterior inferior cerebellar artery origin

Background

Vertebral artery dissecting aneurysm (VADA) involving the origin of the posterior inferior cerebellar artery (PICA) is a complex disease entity in which the dual goals of preventing future rebleeding and maintaining perfusion of the lateral medulla must be considered. We present an illustrative case and review the literature surrounding treatment strategies.

Case Description

We report a patient presenting with extensive subarachnoid hemorrhage due to rupture of an intracranial VADA involving the PICA origin. After consideration of the patient's cerebral vasculature and robustness of collaterals, a flow-diverting stent was placed with angiographic resolution of the lesion and maintenance of antegrade PICA flow. Ultimately, the patient experienced a contralateral intraparenchymal hemorrhage leading to death. Review of the literature identified 124 cases of VADA involving the PICA origin described over the past decade. The methods of surgical and endovascular treatment of these cases were reviewed, with particular focus on the rationale of treatment, outcomes, and complications.

Conclusion

Numerous treatment options for VADA involving PICA have been reported with different risk and benefit profiles. Flow-diverting stents appear to offer the most favorable balance of securing the aneurysm and avoiding medullary infarction, but the risks and optimal anti-thrombotic treatment strategy are incompletely understood. In select cases, in which the surgical risk is low or in which the anatomy is favorable (e.g., nondominant parent vessel or robust collateral circulation in the involved territories), parent artery trapping with or without microsurgical revascularization can be considered.

Pipeline for previously stented basilar trunk aneurysm: a case focusing on how the pipeline should be deployed

Background

Recurrent, previously stented basilar trunk aneurysms pose significant challenges to either microsurgical clipping or traditional endovascular treatment. We here presented an intriguing case that was successfully treated by the pipeline embolization device (PED; ev3/Covidien Neurovascular, Irvine, California, USA).

Case presentation

A 62-year-old male found a recurrent aneurysm, which had been treated with coiling and stent-assisted coiling before. The patient came to our center seeking for a third treatment. In our center, a single PED and additional coils were used to treat this refractory aneurysm. The whole length of the PED was delicately implanted in the previous Enterprise stent (Cordis Corporation, Miami FL, USA), which resembled the double-layer flow diverter FRED (Microvention, Tustin, California, USA). The inflow zone of the aneurysmal sac was further coiled considering that this aneurysm had ruptured. No procedure-related complications occurred. Follow-up angiogram at 6 months indicated that the intractable aneurysm was completely occluded and the patient was free from any neurologic deficit.

Conclusions

This is a case that adds knowledge to improve the poor performance of flow diverters in previously stented aneurysms. However, future studies with larger group of patients are needed to further test the safety and efficacy of this technique.

The Use of Flow Diverter in Ruptured, Dissecting Intracranial Aneurysms of the Posterior Circulation

OBJECTIVE

Acute dissecting aneurysms of the posterior circulation are a rare cause of subarachnoid hemorrhage. Established endovascular treatment options include parent artery occlusion and stent-assisted coiling, but appear to be associated with an increased risk of ischemic stroke. Vessel reconstruction with flow diverters is an alternative treatment option; however, its safety and efficacy in the acute stage remains unclear.

METHODS

This is a multicentric retrospective analysis of 15 consecutive acutely ruptured dissecting posterior circulation aneurysms treated with flow diverters. The primary end point was favorable aneurysm occlusion, defined as OKM C1-3 and D (O'Kelly Marotta scale). Secondary end points were procedure-related complications and clinical outcome.

RESULTS

Nine of 15 aneurysms (60%) arose from the intradural portion of the vertebral artery, 3 were located on the posterior inferior cerebellar artery and 1 each on the anterior inferior cerebellar artery, posterior cerebral artery, and basilar artery. Flow diverter placement was technically successful in 14 of 15 cases (93%). After endovascular treatment, none of the ruptured aneurysms rebled. Median clinical follow-up was 217 days and median angiographic follow-up was 203 days. Favorable occlusion was observed in 7 of 14 aneurysms (50%) directly after flow diverter placement; of those, 5 were completely occluded (36%). Seven patients (47%) with poor-grade subarachnoid hemorrhage died in the acute phase. Favorable clinical outcome (modified Rankin scale ≤2) was observed in 4 of 15 patients (27%) and a moderate outcome (modified Rankin scale 3/4) was observed in 5 of 15 patients (33%). All aneurysms showed complete occlusion at follow-up.

CONCLUSIONS

Flow diverters might be a feasible, alternative treatment option for acutely ruptured dissecting posterior circulation aneurysms and may effectively prevent rebleeding. Larger cohort studies are required to validate these results.

Optional Endovascular Therapy of Dissecting Posterior Cerebral Artery Aneurysm

BACKGROUND

Posterior cerebral artery aneurysms are uncommon, with an occurrence rate of less than 1% of intracranial aneurysms. They have various shapes, including saccular and fusiform. Dissecting aneurysms may occur in distal posterior cerebral artery and they may affect the whole artery. Endovascular therapy is considered as a safe method of treatment and there are different techniques for endovascular therapy.

SUMMARY

Posterior cerebral artery aneurysms are uncommon. Endovascular therapy is considered as a safe method of treatment and there are different techniques for endovascular therapy. We present here three cases collected from Maison Blanche Hospital (Intervention Neuroradiology Department, CHU Reims, France) during 2011-2012; they were females, at a young age and the affected side was on the right. The first case was affected at the P2-P3 segment, the aneurysm was fusiform in shape and she presented with ischemic stroke, while the second and third cases were affected at the P2 segment, the aneurysms being saccular in shape; one of them presented with subarachnoid hemorrhage with a history of migraine and the other patient presented with ischemic stroke. All of them had no history of trauma, hypertension or other diseases. One patient was treated by coiling and sacrificing the parent artery, the second patient was treated with stent-assisted coils, and the third one was treated by coiling without sacrificing the parent artery.

Dissecting intracranial aneurysm in pregnancy: A rare association

We report a case of dissecting aneurysm of the right posterior cerebral artery presenting with sudden onset headache and altered behavior during labor. A 26-year-old P1001 with uncomplicated antenatal period, except history of headache off and on since 32 weeks of pregnancy, developed sudden onset headache and altered behavior during 3^rd stage of labor. She had vaginal delivery and a live born male baby was delivered with good Apgar score. The CT was suggestive of subarachnoid hemorrhage and DSA was suggestive of dissecting aneurysm of the right P2 segment with hypoplasia of right P1 segment and A1 segment of posterior and anterior cerebral artery, respectively. The patient was managed conservatively. At 4-month follow-up, the patient was doing well. We discuss about the rare association of a dissecting aneurysm and pregnancy, especially dissection of the posterior cerebral artery.

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.

Treatment strategies for dissecting aneurysms of the posterior cerebral artery

BACKGROUND

Dissecting aneurysms of the posterior cerebral artery (PCA) are rare and difficult to treat because of their deep and unfamiliar locations and unusual shapes. Although several treatment modalities have been proposed, none have generated satisfying results. Our experiences with PCA-dissecting aneurysms are reviewed and the treatment strategies discussed.

METHODS

All consecutive patients with PCA-dissecting aneurysm who were treated in a tertiary referral hospital between January 1998 and March 2014 were identified by retrospective review. Their clinical characteristics, radiological findings, treatment modalities and outcomes were documented.

RESULTS

Of the 21 patients with 21 PCA-dissecting aneurysms, 9 had subarachnoid hemorrhage and 3 had acute infarction of the thalamus at presentation. The aneurysms involved P1 (n = 4), the P1-2 junction (n = 3), mid-P2 (n = 6), P2A (n = 3), P2P (n = 1) and the P2-3 junction (n = 4). The aneurysm shapes were as follows: fusiform (n = 12), partially thrombosed (n = 8) and blood blister-like aneurysms (n = 1). The mean size was 16.6 ± 9.7 mm. Parent artery occlusion (PAO) without bypass (n = 15), PAO with bypass (n = 2), stent-assisted endosaccular coiling (n = 3) and stent placement only (n = 1) were performed. All three patients who underwent stent-assisted endosaccular coiling and the single patient who underwent PAO without bypass developed aneurysm recurrence. Six of the ten patients who received a PAO without a balloon test occlusion (BTO) experienced PCA territory infarction, whereas only one of the five patients who received a PAO after passing the BTO experienced an infarction.

CONCLUSIONS

PAO for PCA-dissecting aneurysm was effective in preventing recurrence. In addition, BTO before PAO was helpful in identifying candidates who truly needed surgical revascularization.

Surgical distal outflow occlusion for the treatment of complex intracranial aneurysms: experience with 18 cases

BACKGROUND

Selected intracranial aneurysms still require parent artery occlusion. Although such occlusion is usually performed proximal to the aneurysm, in rare instances, it may be difficult or impossible to access the proximal parent artery.

OBJECTIVE

To describe the use of parent artery sacrifice distal to the aneurysm (distal outflow occlusion) in the management of complex aneurysms not amenable to standard microsurgical or endovascular therapy.

METHODS

We reviewed a comprehensive database of intracranial aneurysms evaluated between 1997 and 2013. Hospital records, neuroimaging studies, operative reports, and outpatient clinic notes were examined for all patients treated with distal outflow occlusion.

RESULTS

Eighteen patients (11 women, 7 men; ages 28-69 years) underwent surgical distal outflow occlusion. Eight (44%) underwent concomitant distal revascularization. Intraoperative and delayed postoperative angiography was performed in every case. Nine presented with acute subarachnoid hemorrhage, 1 had a remote bleeding episode. The remaining lesions were unruptured; 3 were discovered incidentally, 3 had symptomatic cerebral edema, 1 had transient ischemic attacks, and 1 had cranial neuropathy. The average follow-up period was 6.5 years; no patient was lost to follow-up review. Two aneurysms required delayed endovascular treatment. Overall, 16 patients achieved a good outcome, 1 had moderate disability, and 1 died.

CONCLUSION

We describe our experience with distal outflow occlusion in the treatment of complex aneurysms not amenable to primary clip reconstruction or endovascular therapy. This technique has been described in very limited fashion in the past and may be particularly useful for patients requiring parent artery occlusion when proximal occlusion is challenging or impossible.

Basilar Artery Dissection Presenting with Subarachnoid Hemorrhage: Report of Two Cases

Basilar artery dissection (BAD) presenting with subarachnoid hemorrhage (SAH) is life-threatening, but its treatment has not been established yet. We treated two patients with ruptured BAD. They were 40-year-old and 41-year-old women. Both of them were treated conservatively during the acute stage. In one patient, radiological abnormality of BAD improved spontaneously. In another patient, reconstructive endovascular treatment (stent with coiling) was required in the chronic stage because the lesion deteriorated morphologically. Neither of them suffered from rebleeding and both had favorable outcome. We reported two patients with ruptured BAD treated conservatively during the acute stage and their outcomes were favorable. We reviewed the literature of BAD presenting with SAH and discussed the management for these lesions.

Subarachnoid hemorrhage then thrombosis of posterior inferior cerebellar artery dissection: is early surgical exploration warranted?

The natural history of spontaneous cerebral artery dissection and thrombosis remains uncertain. Concurrent subarachnoid hemorrhage further complicates the therapeutic approach. Thus the best strategy for managing patients with acute vessel thrombosis in the setting of subarachnoid hemorrhage is unclear. Here we present a case of spontaneous posterior inferior cerebellar artery dissection presenting with subarachnoid hemorrhage and acute thrombosis. Although the patient was initially managed conservatively, angiographic follow-up demonstrated recanalization of the diseased vessel, necessitating definitive treatment. Thus we propose that angiographic follow-up is necessary in the management of patients with subarachnoid hemorrhage in association with apparent vessel thrombosis.

Subarachnoid hemorrhage then thrombosis of posterior inferior cerebellar artery dissection: is early surgical exploration warranted?

The natural history of spontaneous cerebral artery dissection and thrombosis remains uncertain. Concurrent subarachnoid hemorrhage further complicates the therapeutic approach. Thus the best strategy for managing patients with acute vessel thrombosis in the setting of subarachnoid hemorrhage is unclear. Here we present a case of spontaneous posterior inferior cerebellar artery dissection presenting with subarachnoid hemorrhage and acute thrombosis. Although the patient was initially managed conservatively, angiographic follow-up demonstrated recanalization of the diseased vessel, necessitating definitive treatment. Thus we propose that angiographic follow-up is necessary in the management of patients with subarachnoid hemorrhage in association with apparent vessel thrombosis.

Patients with subarachnoid haemorrhage from vertebrobasilar dissection: treatment with stent-in-stent technique

INTRODUCTION

Vertebrobasilar dissection is an uncommon cause of subarachnoid haemorrhage (SAH) that carries a high risk for early repeat haemorrhage. The need for rapid treatment of this disease entity is without question; however, the best method for treatment is still undetermined. Here, we present our results using the stent-in-stent technique, without coiling, for these patients and propose that it is a viable treatment strategy.

METHODS

We identified in our local database for neurointerventional therapy, between 1st October 2000 and 1st January 2014, 93 patients with potential subarachnoid haemorrhage secondary to vertebrobasilar pathology. After review of the clinical notes and imaging, 15 were found to have presented with subarachnoid haemorrhage and treated with stents alone. All dissections were spontaneous with no history of preceding trauma. The ages ranged between 46 and 71 years (mean 61 years).

RESULTS

All patients presented with Fischer grade 4 SAH and had a visible pseudoaneurysm. The pre-operative GCS varied with two patients scoring 3, one patient scoring 6 and the remaining 12 patients scoring 8 or above. All cases were subjected to stent-in-stent treatment alone. We did not experience any intra-procedural complications. In our series, eight patients had full recovery with a Glasgow Outcome Scale (GOS) of 5, three had moderate disability (GOS 4), one had severe disability (GOS 3), and three patents died, one patient from stent thrombosis or re-bleeding and two from their initial SAH.

CONCLUSION

The stent-in-stent technique represents a viable reconstructive endovascular surgical technique with a low risk of intra-procedural complication and post-operative repeat haemorrhage.

Cervical arterial dissections and association with cervical manipulative therapy: a statement for healthcare professionals from the american heart association/american stroke association

PURPOSE

Cervical artery dissections (CDs) are among the most common causes of stroke in young and middle-aged adults. The aim of this scientific statement is to review the current state of evidence on the diagnosis and management of CDs and their statistical association with cervical manipulative therapy (CMT). In some forms of CMT, a high or low amplitude thrust is applied to the cervical spine by a healthcare professional.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee and the American Heart Association's Manuscript Oversight Committee. Members were assigned topics relevant to their areas of expertise and reviewed appropriate literature, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge.

RESULTS

Patients with CD may present with unilateral headaches, posterior cervical pain, or cerebral or retinal ischemia (transient ischemic or strokes) attributable mainly to artery-artery embolism, CD cranial nerve palsies, oculosympathetic palsy, or pulsatile tinnitus. Diagnosis of CD depends on a thorough history, physical examination, and targeted ancillary investigations. Although the role of trivial trauma is debatable, mechanical forces can lead to intimal injuries of the vertebral arteries and internal carotid arteries and result in CD. Disability levels vary among CD patients with many having good outcomes, but serious neurological sequelae can occur. No evidence-based guidelines are currently available to endorse best management strategies for CDs. Antiplatelet and anticoagulant treatments are both used for prevention of local thrombus and secondary embolism. Case-control and other articles have suggested an epidemiologic association between CD, particularly vertebral artery dissection, and CMT. It is unclear whether this is due to lack of recognition of preexisting CD in these patients or due to trauma caused by CMT. Ultrasonography, computed tomographic angiography, and magnetic resonance imaging with magnetic resonance angiography are useful in the diagnosis of CD. Follow-up neuroimaging is preferentially done with noninvasive modalities, but we suggest that no single test should be seen as the gold standard.

CONCLUSIONS

CD is an important cause of ischemic stroke in young and middle-aged patients. CD is most prevalent in the upper cervical spine and can involve the internal carotid artery or vertebral artery. Although current biomechanical evidence is insufficient to establish the claim that CMT causes CD, clinical reports suggest that mechanical forces play a role in a considerable number of CDs and most population controlled studies have found an association between CMT and VAD stroke in young patients. Although the incidence of CMT-associated CD in patients who have previously received CMT is not well established, and probably low, practitioners should strongly consider the possibility of CD as a presenting symptom, and patients should be informed of the statistical association between CD and CMT prior to undergoing manipulation of the cervical spine.

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.

Clinical characteristics of symptomatic vertebral artery dissection: a systematic review

BACKGROUND

Vertebral artery dissection (VAD) is an important cause of stroke in the young. It can present nonspecifically and may be misdiagnosed with adverse consequences. We assessed the frequency of head/neck pain, other neurological symptoms, and cerebrovascular events in symptomatic VAD.

METHODS

We conducted a systematic review of observational studies, searching electronic databases (MEDLINE, EMBASE) for English-language manuscripts with >5 subjects with clinical or radiologic features of VAD. Two independent reviewers selected studies for inclusion; a third adjudicated differences. Studies were assessed for methodological quality, and clinical data were abstracted. Pooled proportions were calculated.

RESULTS

Of 3996 citations, we screened 511 manuscripts and selected 75 studies describing 1972 VAD patients. The most common symptoms were dizziness/vertigo (58%), headache (51%), and neck pain (46%). Stroke was common (63%), especially with extracranial dissections (66% vs. 32%, P<0.0001), whereas transient ischemic attack (14%) and subarachnoid hemorrhage (10%) were uncommon. Subarachnoid hemorrhage was seen only with intracranial dissections (57% vs. 0%, P=0.003). Fewer than half of the patients had obvious trauma, and only 7.9% had a known connective tissue disease. Outcome was good (modified Rankin scale 0 to 1) in 67% and poor (modified Rankin scale 5 to 6) in 10% of patients.

CONCLUSIONS

VAD is associated with nonspecific symptoms such as dizziness, vertigo, headache, or neck pain. Ischemic stroke is the most common reported cerebrovascular complication. VAD should be considered in the diagnostic assessment of patients presenting with dizziness or craniocervical pain, even in the absence of other risk factors. Future studies should compare clinical findings as predictors in well-defined, undifferentiated populations of clinical VAD suspects.

Traumatic dissecting posterior cerebral artery aneurysm. A case report and review of the literature

Dissecting posterior cerebral artery (PCA) aneurysms are among rare cerebrovascular malformations accounting for 2% to 6% of all aneurysms. Herein we describe a case of pediatric dissecting aneurysm located in the PCA with documentation of aneurysm development. In addition, we discuss its treatment with a new therapeutic method involving glue injection.

Altered hemodynamics associated with pathogenesis of the vertebral artery dissecting aneurysms

The etiology of the vertebral dissecting aneurysms is largely unknown, and they frequently occurs in relatively healthy young men. Objectives and Methods. A series of 57 consecutive cases defined by angiography were evaluated with regard to deviation in the course of the affected and contralateral vertebral arteries. Division was into 3 types: Type I without any deviation, Type II with mild-to-moderate deviation but not over the midline; and Type III with marked deviation over to the contralateral side beyond the midline. Results. The most frequent type of VA running was Type III for the affected and Type I nonaffected side, with this being found in all 17 patients except one. All of the Type III dissections occurred just proximal to a tortuous portion, while in cases with Type-I- and Type-II-affected sides, the majority (33 of 39) occurred near the union of the vertebral artery. In 10 of 57, a non-dominant side was affected, all except one being of Type I or II. With 12 recent patients assessed angiographically in detail for hemodynamics, eleven patients showed contrast material retrograde inflowing into the pseudolumen from the distal portion of the dissection site. Turbulent blood flow was recognized in all of these patients with retrograde inflow. Conclusions. Turbulent blood flow is one etiology of vertebral artery dissection aneurysms, with the sites in the majority of the cases being just proximal to a tortuous portion or union of vessels. In cases with dissection proximal to the tortuous course of the vertebral artery, retrograde inflow will occur more frequently than antegrade, which should be taken into account in designing therapeutic strategies.

Dissecting aneurysms of posterior cerebral artery: clinical presentation, angiographic findings, treatment, and outcome

BACKGROUND

The dissecting posterior cerebral artery (PCA) aneurysms are very rare. These aneurysms pose significant treatment challenge and need careful evaluation to formulate an optimal treatment plan in case of ruptured or un-ruptured presentations.

METHODS

Retrospective review of a prospectively collected data.

RESULTS

Seven patients with dissecting aneurysms of the PCA were identified. Six out of seven presented with subarachnoid hemorrhage (SAH) and one with ischemic stroke. Three out of seven were treated with endovascular coil embolization without sacrifice of the parent artery and the rest had parent artery occlusion (PAO) with coil embolization. None of the patients developed new neurological deficits post-procedure. Aneurysm re-occurred in two patients that were treated without PAO.

CONCLUSION

Endovascular treatment of the dissecting PCA aneurysm is safe and feasible. It can be performed with or without PAO. Recurrence is more common without PAO and close follow-up is warranted.

Spontaneous intra-cranial arterial dissection frequently causes anterior cerebral artery infarction

BACKGROUND AND PURPOSE

Spontaneous intra-cranial arterial dissection (SICAD) without history of head and neck injury is now recognized as an important cause of stroke. However, the frequency of SICAD involving the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) territories remains unclear. This study therefore investigated the distribution of SICAD.

METHODS

Subjects comprised 194 patients (126 men, 68 women; median age, 68.0 years) with infarct isolated to the ACA, MCA or PCA territories who underwent conventional angiography. Diagnosis of SICAD was based on clinical and neuroradiological findings. Frequency of SICAD was compared among ACA, MCA, and PCA infarcts. All patients were divided into SICAD and non-SICAD groups, and clinical characteristics were compared between groups.

RESULTS

Infarcts involved the ACA in 14 cases (7.2%), MCA in 165 cases (85.1%), and PCA in 15 cases (7.7%). SICAD was diagnosed in 17 of 194 cases (8.8%), with cerebral angiography showing main findings of the string sign in 11 patients (64.7%), the pearl and string sign in 6 patients (35.3%), and pseudoaneurysm formation in 2 patients (11.7%). SICAD most frequently involved the ACA (ACA, 64.3%; MCA, 4.2%; PCA, 6.7%; P<0.001).

CONCLUSION

SICAD was seen in 64.3% of patients with ACA infarct. The mechanisms of ACA infarction may thus differ from those of MCA and PCA infarction.

Subarachnoid hemorrhage from a dissecting aneurysm of the posterior cerebral artery in a child : rebleeding after stent-assisted coiling followed by stent-within-stent technique

Pediatric patients with dissecting aneurysms usually present with ischemia rather than bleeding. We report a case of a 15-year-old boy with a dissecting aneurysm of the posterior cerebral artery (PCA) presenting with hemorrhage. He was first treated with stent-assisted coil embolization, in an attempt to avoid trapping of the PCA and preserve the perforators. After the procedure, he recovered well from general anesthesia, but rebleeding occurred from the same lesion 6 hours after the procedure, therefore endovascular segmental occlusion of the parent artery was performed secondarily. Apparently, a reconstructive method of stent-assisted coiling is worth trying to preserve the parent vessel and perforators, but it is not always efficient and durable for dissecting aneurysms.

Aneurysms of the posterior cerebral artery and approach selection in their microsurgical treatment: emphasis on the approaches: SAHEA and SCTTA

Aneurysms of the posterior cerebral artery (PCA) are infrequent and located in the central depth of the brain. Hence their optimal microsurgical management has not been discussed systematically, as institutions and/or neurosurgeons have only limited experience. The purpose of this communication is to report our considerations on this topic with emphasis on the selection of approaches by reviewing our 20 consecutive cases of PCA aneurysms out of more than 1,000 aneurysm patients seen over the past 15 years. Although the subtemporal approach appears to be prevalent in the literature, in our series we applied the pterional approach with or without selective extradural anterior clinoidectomy (SEAC) for P1, P1-P2 aneurysms, and either a selective amygdalohippocampectomy approach (SAHEA) or supracerebellar transtentorial approach (SCTTA) for P2 and P2-P3 aneurysms. Construction of an extracranial-intracranial EC-IC bypass, when necessary, in conjunction with parent artery occlusion or with trapping of aneurysms was adapted to selected approaches.

Cerebrovascular Dissections—A Review Part I: Spontaneous Dissections

Spontaneous cerebrovascular dissections are subintimal or subadventitial cervical carotid and vertebral artery wall injuries and are the cause of as many as 2% of all ischemic strokes. Spontaneous dissections are the leading cause of stroke in patients younger than 45 years of age, accounting for almost one fourth of strokes in this population. A history of some degree of trivial trauma is present in nearly one fourth of cases. Subsequent mortality or neurological morbidity is usually the result of distal ischemia produced by emboli released from the injury site, although local mass effect produced by arterial dilation or aneurysm formation also can occur. The gold standard for diagnosis remains digital subtraction angiography. Computed tomography angiography, magnetic resonance angiography, and ultrasonography are complementary means o evaluation, particularly for injury screening or treatment follow-up. The annual rate of stroke after injury is approximately 1% or less per year. The currently accepted method of therapy remains antithrombotic medication, either in the form of anticoagulation or antiplatelet agents; however, no class I medical evidence exists to guide therapy. Other options for treatment include thrombolysis and endovascular therapy, although the efficacy and indications for these methods remain unclear.

Simultaneous occurrence of subarachnoid hemorrhage and cerebral infarction caused by anterior cerebral artery dissection treated by endovascular trapping

A 48-year-old man presented with a rare dissection of the anterior cerebral artery (ACA) causing simultaneous subarachnoid hemorrhage (SAH) and cerebral infarction manifesting as sudden onset of headache and left hemiparesis. Computed tomography and magnetic resonance imaging showed SAH localized in the interhemispheric fissure and cerebral infarction in the territory of the right ACA. Digital subtraction angiography (DSA) demonstrated segmental narrowing and dilatation at the right A(1) and A(2) portions of the ACA, leading to a diagnosis of ACA dissection. Fourteen days after the onset, DSA confirmed the enlarged fusiform dilatation of the right A(2) portion with distal narrowing, suggesting the risk of rerupture of the dissection. Endovascular obliteration of the aneurysm with parent artery occlusion was performed without anastomosis on day 16. The aneurysm was catheterized and obliterated with detachable coils. Postoperative DSA revealed complete obliteration of the dissection and parent artery. The patient was doing well without recurrence of the dissection 8 months after the intervention. The simultaneous occurrence of SAH and cerebral infarction in patients with ACA dissection is extremely rare, and the optimal treatment has not yet been established. Endovascular treatment is safe and effective for the treatment of ACA dissection.

Cerebral aneurysms in children: are we talking about a single pathological entity?

PURPOSE

The objective of this article is to highlight the fact that cerebral aneurysms in children are heterogeneous unlike in the adult population.

MATERIAL AND METHODS

This is a retrospective review of 17 children with intracranial aneurysms who were managed at a single institution from 2004 to 2009.

RESULTS

The median age was 12 years (range 10 months-17 years). Sixty-five percent of the aneurysms were saccular and 24% were fusiform. There was one infectious and one distal lenticulostriate aneurysm. Patients with saccular aneurysms were predominantly male and presented more commonly with intracranial hemorrhage (91%). The fusiform aneurysms were dissecting in nature or chronic with intramural thrombus and mass effect. The treatment was dependent upon the type and location of the aneurysm.

CONCLUSION

Pedriatic aneurysms are a heterogeneous group of intracranial arterial diseases with different etiologies, diverse morphology, and dissimilar clinical manifestations.

Intracranial arterial dissections in ischemic stroke assessed by 3D rotational angiography

BACKGROUND

Dissections involving intracranial arteries are sometimes difficult to assess using conventional digital subtraction angiography (DSA). We evaluated the value of three-dimensional rotational angiography (3D-RA) for the assessment of intracranial arterial dissections (ICADs).

METHODS

The subjects were 39 patients (26 males, 13 females; average age 50+/-15years) who were diagnosed as having ICADs and who underwent both DSA and 3D-RA in our hospital between April 1999 and March 2005. We retrospectively compared 3D-RA images to conventional DSA images in a blinded manner with respect to double lumen sign, pearl and string sign, string sign, and aneurysmal dilatation. On the basis of the caliber size of the artery affected by dissections, we divided patients into two groups: smaller artery group (S group) and larger artery group (L group).

RESULTS

The detection rate of double lumen sign with 3D-RA (79%) was significantly higher than with conventional DSA (18%; P<0.001). Reliable findings of arterial dissections (double lumen sign and/or pearl and string sign) were observed more often with 3D-RA (90%) than with conventional DSA (36%; P<0.001). In S group, the double lumen sign was detected only with 3D-RA.

CONCLUSIONS

3D-RA allows increased conspicuity of ICADs findings with conventional DSA, especially in smaller-caliber intracranial arteries.

Overview of spontaneous cervicocephalic arterial dissection in Japan

Spontaneous cervicocephalic arterial dissection (SCAD) has been recognized as an uncommon cause of cerebral stroke. Although it has been viewed as an important cause of stroke, especially in juvenile cases, its natural course and pathophysiology have yet to be fully clarified, and no treatment criteria have been established. Recent studies have suggested that clinical features of SCAD in Japan are different from those in European countries. Herein, we reviewed the current status of the management of SCAD in Japan, and clarified its clinical characteristics to establish an appropriate treatment.

Remote distal outflow occlusion: a novel treatment option for complex dissecting aneurysms of the posterior inferior cerebellar artery. Report of 3 cases

The authors report a novel management option for patients with complex dissecting aneurysms of the posterior inferior cerebellar artery (PICA). The authors reviewed the medical records and neuroimaging studies of 3 patients who underwent a novel surgical treatment for complicated dissecting PICA aneurysms. The mean follow-up period was 1.1 years, and no patient was lost to follow-up. Two patients were in poor condition following an acute, severe subarachnoid hemorrhage, and 1 presented with headaches and a remote history of bleeding. All patients underwent surgical occlusion of the PICA beyond the tonsillar loop, distal to the aneurysmal segment. Intraoperative and delayed follow-up angiography demonstrated progressive diminution in size of the aneurysmal dilation but persistent filling of the proximal PICA segments supplying the brainstem. Outcome was good in all cases. This novel technique has been used successfully in 3 cases and, to the authors' knowledge, has not been reported previously.

Endovascular strategies for vertebrobasilar dissecting aneurysms

BACKGROUND AND PURPOSE

Dissecting vertebrobasilar aneurysms are challenging to treat, and standard treatment modalities remain controversial. We retrospectively evaluated our experience using endovascular techniques to treat these aneurysms.

MATERIALS AND METHODS

From February 1997 to December 2007, 42 patients with intradural vertebrobasilar dissecting aneurysms underwent endovascular treatment. Twenty-nine patients had ruptured aneurysms, and 13 patients had unruptured dissecting aneurysms. The endovascular modalities for vertebrobasilar dissecting aneurysms were the following: 1) trapping (n = 30), 2) proximal occlusion (n = 3), 3) stent with coil (n = 6), and 4) stent alone (n = 3).

RESULTS

Seventeen of the 29 patients with ruptured vertebrobasilar dissecting aneurysms had successful outcomes without procedural complications following endovascular treatment. Procedure-related complications were the following: 1) rebleeding (n = 3), 2) posterior inferior cerebellar artery (PICA) territory infarction (n = 6), 3) brain stem infarction (n = 2), and 4) thromboembolism-related multiple infarctions (n = 1). Clinical outcomes were favorable in 32 patients (76.1%). There were 3 (7.1%) procedure-related mortalities due to rebleeding, and 1 (2.4%) non-procedure-related mortality due to pneumonia sepsis. All 13 patients with unruptured vertebrobasilar dissecting aneurysms had favorable clinical and radiologic outcomes without procedure-related complications.

CONCLUSIONS

Endovascular procedures for treatment of unruptured symptomatic dissecting aneurysms resulted in favorable outcomes. Ruptured vertebrobasilar dissecting aneurysms are associated with a high risk of periprocedural complications. Risks can be managed by using appropriate endovascular techniques according to aneurysm location, configuration, and relationship with the PICA.

Endovascular management of posterior cerebral artery aneurysms. Initial experience

SUMMARY

The purposes of this study were to evaluate the efficacy and safety of the endovascular management of posterior cerebral artery aneurysms and compare the efficacy and safety of selective aneurysmal coiling and parent artery occlusion. We reviewed all cases with cerebral aneurysms and attention was paid to the patients with posterior cerebral artery aneurysms. Among 550 aneurysms, eight aneurysms in eight patients were located on the posterior cerebral artery, three of which presented with SAH, whereas five presented with different degrees of headache. Seven were located at the P2 segment and one at the P3 segment. One was a giant serpentine aneurysm, two were giant sac aneurysms, two were large and three were small. All aneurysms were successfully treated, five with selective aneurysmal coiling and three with parent artery occlusion. Two patients presenting with headache with giant aneurysms had suffered an aggravated headache for two weeks which then resolved. Others had an uneventful recovery. All patients were followed from 12 months to 56 months. Four selective aneurysmal coiling aneurysms received digital subtraction angiography, two of which needed another treatment and one was treated with parent artery occlusion, one of which recanalized slightly and one of which had further thrombosis. No rebleeding or any other symptom occurred. Whether selective aneurysmal coiling or parent artery occlusion was performed, endovascular management of PCA aneurysms was a safe and effective method. Under some conditions, parent artery occlusion was better than selective aneurysmal coiling.

Dissecting aneurysms of the posterior inferior cerebellar artery: retrospective evaluation of management and extended follow-up review in 6 patients

OBJECT

The authors report the management protocol and successful outcomes in 6 patients with dissecting aneurysms of the posterior inferior cerebellar artery (PICA).

METHODS

Medical records and neuroimaging studies of 6 patients who underwent surgical treatment of dissecting PICA aneurysms were reviewed. The mean follow-up duration was 1.8 years. No patient was lost to follow-up review.

RESULTS

Four patients presented with acute subarachnoid hemorrhage and 2 with PICA ischemia. All patients underwent surgery, which entailed proximal occlusion with distal revascularization in 3 cases and circumferential wrap/clip reconstruction in 3 cases. The revascularization techniques used were occipital artery-PICA bypass and PICA-PICA anastomosis. Delayed follow-up angiography was performed in all cases. In patients treated with proximal occlusion, delayed angiography showed minimal retrograde opacification of the dissected segments. The 3 patients treated with wrap/clip reconstruction showed unexpectedly significant normalization of their lesions on angiographic studies. Outcome was good in all cases.

CONCLUSIONS

Dissecting PICA aneurysms are rare lesions with an apparent propensity for bleeding. Individualized management including distal revascularization with PICA sacrifice or circumferential wrap/clip reconstruction to reinforce the dissected segment produced good outcomes. Patients treated with aneurysm wrapping may show dramatic angiographic improvement of the dissected segment.

Isolated internal auditory artery aneurysm

Anticoagulant therapy is effective and prevents death in more than 95% of patients with pulmonary embolism following deep vein thrombosis. We report a patient who developed deep vein thrombosis following rupture of a dissecting aneurysm of the internal auditory artery. The parent artery was occluded before anticoagulant therapy as a prophylactic measure to prevent intracranial haemorrhage. We discuss some of the clinical features, therapeutic difficulties, and pitfalls in the management of internal auditory artery aneurysm complicated by deep vein thrombosis.

Spontaneous resolution of isolated dissecting aneurysm on the posterior inferior cerebellar artery

The authors report a rare example of an isolated dissecting posterior inferior cerebellar artery (PICA) aneurysm with spontaneous resolution. A 41 year-old male suffered sudden dizziness, nausea and vomiting. An angiogram and magnetic resonance imaging (MRI) detected an isolated PICA dissection. The patient was treated conservatively and recovered without any apparent neurological deficit. MRI detected the self-resolution of the dissecting aneurysm. Dissecting PICA aneurysms, especially non-haemorrhagic lesions, have the possibility of spontaneous resolution resulting in a favorable outcome. The treatment strategy for this vascular lesion may be decided based upon neuroradiological changes on careful follow-up.

Subarachnoid hemorrhage as a presentation of basilar artery dissection

INTRODUCTION

Subarachnoid hemorrhages caused by intracranial dissections are rare. The management of dissections in these cases not clear.

METHODS

Case report.

RESULTS

An 82-year-old woman presented with acute drowsiness and vomiting. CT scan demonstrated extensive subarachnoid hemorrhage and hydrocephalus that subsequently required placement of ventriculoperitoneal shunt. Angiography revealed extensive basilar artery dissection and no aneurysms. The dissection did not produce a critical stenosis and, taking into consideration that the patient had a previous occlusion of her distal left vertebral artery, it was decided to manage the patient conservatively. On a 3-month follow-up, the patient was free of recurrent events.

CONCLUSION

Basilar artery dissection can present with subarachnoid hemorrhage. No guidelines are available for management of basilar artery dissections and treatment should be tailored to the individual patient.

Idiopathic aneurysms of distal cerebellar arteries: endovascular treatment after rupture

INTRODUCTION

Idiopathic ruptured aneurysms of distal cerebellar arteries (DCAAs) are rare, and their endovascular therapy (EVT) has as yet not been extensively reported. They are usually assumed to result from local arterial wall disruption rather than infection, unlike distal supratentorial artery aneurysms. This study was performed to audit their frequency, potential aetiology and results of EVT.

PATIENTS AND METHODS

Using strict inclusion criteria and a database of 1715 EVT patients, we identified ten idiopathic ruptured DCAAs (0.6%) over a 13-year period (1993-2006). The series comprised six males and four females with mean age of 64 years and solitary aneurysms located on posterior inferior cerebellar artery (five patients), anterior inferior cerebellar artery (three patients) and superior cerebellar artery (two patients). Nine aneurysms were fusiform and were treated by endovascular parent artery occlusion, and one was saccular and treated by endosaccular packing. Endovascular therapy was performed with coils in seven cases, n-butyl-2-cyanoacrylate (NBCA) in two cases and with both in one case.

RESULTS

Primary EVT was successful in eight patients. One patient died following a procedure-related re-bleeding and one patient required re-treatment after failed endosaccular packing. Nine patients made good or excellent clinical recoveries (modified Rankin Scale 2 or less). Focal cerebellar infarctions were seen on computed tomography images after EVT in three patients, only one of whom was symptomatic with transient dysmetria, which resolved completely during follow up. No aneurysm recanalisation was detected on late follow-up imaging up to 24 months.

CONCLUSION

Ruptured DCAAs are rare. The majority are fusiform in shape and their aetiology remains uncertain. Endovascular treatment is feasible and effective. It usually requires parent artery occlusion.