Spontaneous dissecting aneurysms of the basilar artery presenting with a subarachnoid hemorrhage. Report of two cases

Dissecting Aneurysm of the Basilar Artery-A Rare Complication of Bacterial Meningitis in a Postoperative Case of CSF Rhinorrhea

Basilar artery dissections are rare events which present with subarachnoid hemorrhage (SAH), brain ischemia, and usually have a fatal outcome. Few case reports of mycotic dissections are published in literature. We report a case of a young male who underwent surgical treatment for post-traumatic CSF rhinorrhea. He presented 3 years later with signs of bacterial meningitis. During medical management with antibiotic therapy, he developed basilar artery aneurysm in a span of 2 days, had subarachnoid hemorrhage and deteriorated. CSF culture grew alpha hemolytic streptococci. Despite medical management, he developed brain stem infarcts and succumbed. This report highlights a rare fatal complication of mycotic dissecting aneurysm of the basilar artery following meningitis, which developed acutely in hospital, while on treatment. Antibiotic therapy had not altered the course of disease. It is advisable to investigate for presence of ruptured mycotic aneurysms or dissection in cases of bacterial meningitis leading to SAH.

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.

Stent treatment for basilar artery dissection: A single-center experience of 21 patients

Basilar artery dissection is a rare disease with high morbidity and mortality. No well-established management strategy exists for this lesion. Endovascular reconstructive therapy using stents (with or without coiling) may be the optimum strategy.We describe our center's experience for this treatment strategy in 21 patients with basilar artery dissection from January 2009 to July 2014 (17 men, four women; age range, 18-70 years; median age, 56 years). We divided patients into two groups: Group 1 patients received stent-assisted coiling treatment, and Group 2 patients received stent-only treatment. Pre-treatment, peri-operation and follow-up evaluation were investigated for complications, clinical outcome and angiographic results. The median follow-up time was 20 months (range, 3-67 months).All patients were treated endovascularly by stent-assisted coiling (14 patients) or stent only (seven patients). Immediate angiography showed: in Group 1, five of 14 lesions were completely occluded, five were partially occluded, four revealed retention of contrast media; in Group 2, all patients (seven of seven) had contrast retention. At the follow-up visit (median seven months, 3-29 months), the aneurysms were angiographically improved in five of 13 patients in Group 1 compared with immediately post-operation, while six of sevenimproved in Group 2. Five patients (all in Group 1) had ischemic or hemorrhage peri-operation complications. Long-term good clinical outcomes (modified Rankin Scale score (mRS) ≤ 2) were achieved in all patients except three death cases (two in Group1, one in Group 2).In our experience, endovascular reconstructive therapy using stents (with or without coiling) for basilar artery dissection is effective and safe. Stent-only treatment seems have a better safety profile during the peri-operation period.

Endovascular Treatment in Ruptured Middle Cerebral Artery Dissection Preservation of Arterial Continuity

Rupture of spontaneous dissecting aneurysms of the middle cerebral artery (MCA) is rare and its etiology remains obscure, although the risk of rebleeding is greater than with saccular aneurysms. Most reports concerning the treatment of a ruptured dissecting aneurysm of the anterior circulation involve surgical trapping or wrapping. Here, we report on a case of an MCA dissecting rupture treated with endovascular procedures. A 22-year-old female presented with sudden stuporous mental change following severe headache and left side hemiparesis. A computed tomography scan showed a diffuse subarachnoid hemorrhage and diffusion MR showed diffusion restriction at the right putamen and internal capsule. A 3-hour follow-up digital subtraction angiography (DSA) showed a dissecting aneurysm, which was not seen on an initial DSA. A stent assisted coil embolization was performed and double stents were applied to achieve flow diversion effects. A small remnant area of the dissecting aneurysm had disappeared at 60-day and was not observed on 12-month follow-up DSA.

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.

Predictors of Favorable Outcome of Intracranial Basilar Dissecting Aneurysm

BACKGROUND

Management of intracranial basilar dissecting aneurysms has been controversial and challenging, and surgical and conservative treatments usually have a bad prognosis. Our study aimed at evaluating the outcomes of endovascular treatment for these lesions and exploring the predictors of favorable outcome.

METHODS

We retrospectively reviewed 50 consecutive patients with basilar dissecting aneurysms from January 2006 to January 2013. Twenty-four patients underwent stent-assisted coiling whereas 26 patients underwent conservative treatment. Follow-up outcomes were evaluated using modified Rankin Scale (mRS) score.

RESULTS

Of the patients treated with stent-assisted coiling, 20 patients had a favorable outcome (mRS score, 0-1), post-treatment recurrence occurred in 3 patients, 1 had rebleeding, and 2 had no rebleeding. Of the patients treated with conservative therapy (observation or anticoagulation), 10 patients had an unfavorable outcome, 2 patients with ruptured aneurysms developed rebleeding, and 8 patients had poor outcome because of infarct progression. Stent-assisted coiling group had a more favorable outcome than the conservatively treated group (83.3% versus 55.2%, P = .019). Initial complete obliteration was related to the favorable outcome in endovascular-treated group (P = .042). Stent placement was the only independent predictor of favorable outcome in the logistic regression analysis (P = .030; odds ratio = 5.828; 95% confidence interval, 1.192-28.503).

CONCLUSIONS

Patients with basilar artery dissecting aneurysms treated with stent-assisted coiling had a more favorable outcome than the conservatively treated patients. Stent placement and initial complete occlusion were the favorable factors in patients with basilar dissecting aneurysm.

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.

Multiple non-branching dissecting aneurysms of the mid-basilar trunk presenting with sequential subarachnoid hemorrhages

OBJECTIVE

We describe a rare case of a patient with subarachnoid hemorrhage (SAH) due to a ventral dissecting mid-basilar aneurysm that was treated surgically. One week after surgery, the patient experienced sudden deterioration due to a new SAH caused by the development of a new aneurysm of the basilar trunk distinct from the previously clipped aneurysm.

CASE DESCRIPTION

A 54-year-old woman with acute subarachnoid hemorrhage was found to have a small, broad-based aneurysm arising from the ventral aspect of the mid-basilar artery. This complicated lesion was treated with a microsurgical clipping via a translabyrinthine pre-sigmoidal sub-temporal approach. One week postoperatively, the patient suffered a new SAH and was found to have developed a distinct basilar artery aneurysm. The patient was returned to the Operating Room for microsurgical clipping via the previous craniotomy. After surgery, the patient made a slow, but steady, recovery. She underwent repeated angiographic imaging, demonstrating a stable appearance. Two years post surgery, the patient had returned to work and had no obvious neurological deficit, with the exception of unilateral iatrogenic hearing loss.

CONCLUSION

We describe a rare case of multiple aneurysms originating in relation to a mid-basilar dissection, resulting in multiple episodes of SAH. These are difficult and dangerous lesions that can be treated with open microsurgical reconstruction or possibly via an endovascular approach. The intricate location of the lesions poses a particular challenge to neurosurgeons attempting to directly treat mid-basilar lesions.

Delayed thrombosis of the basilar artery after stenting for a basilar trunk dissection aneurysm. A case report and review of the literature

A 30-year-old man was referred in our department for treatment of a midbasilar trunk aneurysm. His presenting symptoms included headache and dizziness. A CT scan at another hospital showed no significant findings whereas a digital subtraction angiogram disclosed a dissecting aneurysm in the midbasilar trunk, and there was severe stenosis in the basilar artery. After discussion, we planned to use stent-assisted-coil embolization technique. During the procedure, a LEO stent (Balt, Montmorency, France) was implanted into the basilar artery across the aneurysm neck, but fearing acute basilar artery occlusion because of stent collapse or thrombus we did not fill coils into the aneurysm. After the procedure, the completion angiography demonstrated considerably decreased flow into the aneurysm, with stasis persisting into the venous phase of angiography. The patient awoke from general anaesthesia after the procedure and had no additional neurological symptoms, he was discharged three days later and used clopidogrel and aspirin for antiplatelet therapy. Six months later when he was admitted for a recheck, a DSA showed the basilar artery was occluded completely and the aneurysm had disappeared even though the patient remained neurologically normal.

Management and clinical outcome of acute basilar artery dissection

BACKGROUND AND PURPOSE

There have been inconsistencies on the prognosis and controversies as to the proper management of acute basilar artery dissection. The aim of this study was to evaluate acute basilar artery dissection and its outcome after management.

MATERIALS AND METHODS

A total of 21 patients (mean age, 53 years; range, 24-78 years) with acute basilar artery dissection were identified between January 2001 and October 2007. Clinical presentation, management, and outcomes were retrospectively evaluated.

RESULTS

The patients presented with subarachnoid hemorrhage (n = 10), brain stem ischemia (n = 10), or stem compression sign (n = 1). Ruptured basilar artery dissections were treated by stent placement with coiling (n = 4), single stent placement (n = 3), or conservatively (n = 3). Of the patients treated with endovascular technique, 6 had favorable outcome (modified Rankin scale [mRS], 0-2) and the remaining patient, who was treated by single stent placement, died from rebleeding. All 3 conservatively managed patients experienced rebleeding, of whom 2 died and the other was moderately disabled. Unruptured basilar artery dissections were treated conservatively (n = 7) or by stent placement (n = 4). Of the patients with unruptured basilar artery dissection, 9 had favorable outcome and the remaining 2 patients, both of whom were conservatively managed, had poor outcome because of infarct progression. The group with the ruptured basilar artery dissection revealed a higher mortality rate than the group with the unruptured dissection (30% vs 0%). The group treated with endovascular means revealed more favorable outcome than the group that was treated with conservative measures (90.9% vs 50%).

CONCLUSION

The ruptured basilar artery dissections were at high risk for rebleeding, resulting in a grave outcome. Stent placement with or without coiling may be considered to prevent rebleeding in ruptured basilar dissections and judiciously considered in unruptured dissections with signs of progressive brain stem ischemia.

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.

Dissecting aneurysms limited to the basilar artery: report of two cases and review of the literature

Spontaneous dissecting aneurysms limited to the basilar artery are rare. We describe two patients who presented to our institution with different clinical problems, one with brain stem infarction and the other with subarachnoid hemorrhage. We describe the clinical and imaging features in these patients, their treatment, and outcome. We also reviewed the literature concerning this entity, and we have identified 32 patients (including our two patients) with angiographically confirmed dissecting aneurysms limited to the basilar artery. Of these, 40.6% presented with brain stem infarction, 50.0% presented with subarachnoid hemorrhage, and 9.4% presented with both infarction and subarachnoid hemorrhage. Patients who presented with basilar artery dissecting aneurysms and brain stem infarction tended to be younger (mean age, 38 +/- 7 years) than those who presented with subarachnoid hemorrhage (48 +/- 12 years) and were more likely to be male. We discuss the natural history of this entity and suggest an approach to clinical management for these patients.

Endovaskulärer Verschluss der A. basilaris zur Behandlung dissektionsbedingter und dysplastischer fusiformer Aneurysmen

Dissecting aneurysms of the basilar artery trunk frequently affect young adults. Fusiform shape and narrowing of the proximal parent artery are typical features. Changes in aneurysm size and geometry may be observed more rapidly than in atherosclerotic or dysplastic aneurysms. Dissecting aneurysms carry a significant risk of rupture. Thrombotic or embolic occlusion of small pontine branches may cause ischemic symptoms. Sufficiently large aneurysms compress the adjacent brainstem. The operative treatment of these aneurysms is associated with unacceptable risks. At least one posterior communicating artery with normal calibre together with the ipsilateral P1 segment needs to provide adequate collateral flow to the upper basilar artery to allow endovascular coil occlusion of the segment that is affected by the dissection and/or fusiform aneurysmal dilatation. Four illustrative cases of endovascular coil occlusion of the basilar artery for the treatment of fusiform aneurysms are presented and discussed.

Staged bilateral vertebral artery occlusion for ruptured dissecting aneurysms of the basilar artery: a report of 2 cases

BACKGROUND

Dissecting aneurysm of the basillary artery BA is rare. Although mortality rate is high, management remains controversial. We report 2 cases of dissecting aneurysm of the BA presenting with subarachnoid hemorrhage (SAH), both of which were successfully treated using staged occlusion of bilateral vertebral arteries (VAs).

CASE DESCRIPTION

A 64-year-old man and a 34-year-old woman presented with SAH associated with ruptured dissecting aneurysm of the BA. After endovascular occlusion of a single VA, blood flow in the dissected lumen was reduced. However, one aneurysm rebled and the bleb of the other did not change. Vertebral arteries were also occluded using endovascular techniques at 4 and 2 weeks after initial treatment, respectively. On the second intervention, stump pressure ratios of VAs intended for occlusion were 62.5% and 50.6%, respectively. The patients tolerated temporary occlusion of bilateral VAs well. Subsequent permanent occlusion of bilateral VAs resulted in no neurological complication. Complete obliteration of the aneurysmal lumen was demonstrated on magnetic resonance angiography performed 72 and 5 months later, respectively.

CONCLUSION

Staged bilateral VA occlusion might be the last recourse to prevent further hemorrhage from BA dissecting aneurysm. The technique can be safely applied when the stump pressure ratio is 50.6% or greater and when the patient tolerates temporary occlusion, which suggests the existence of sufficient collateral flow from the anterior circulation.

Late morphological progression of a dissecting basilar artery aneurysm after staged bilateral vertebral artery occlusion: case report

BACKGROUND

The authors present a patient who experienced late (5-year follow-up) morphological progression of a dissecting aneurysm of the distal basilar artery after treatment with a combined microsurgical and neuroendovascular Hunterian strategy. In addition to postulating about the possible reasons underlying the evolution of this lesion, the role of stenting is discussed.

CASE DESCRIPTION

The patient was 37 years old when she suffered a subarachnoid hemorrhage from spontaneous basilar artery dissection. At the time of the hemorrhage, minimal aneurysmal enlargement was noted angiographically, and she was therefore treated nonoperatively. On reimaging 5 months later, massive enlargement of the aneurysm was noted. The patient was treated with staged bilateral vertebral artery sacrifice using a combination of microsurgical and neuroendovascular techniques. The dominant vertebral artery was clip-ligated distal to the posteroinferior cerebellar artery, whereas the contralateral vertebral artery was coil-occluded cervically 1 week later.

CONCLUSIONS

Despite the patient remaining asymptomatic, follow-up angiography 5 years after the initial hemorrhage revealed further enlargement of the aneurysm as well as a newly discovered inferiorly projecting daughter sac measuring 5 mm in diameter. Clearly, certain aneurysms exist for which indirect approaches involving hemodynamic attenuation fail to prevent progression. With greater refinements in stent technology, such lesions may be more effectively treated.

Basilar artery dissection

Object. Little is understood about the clinical manifestations of basilar artery (BA) dissections, which can present with subarachnoid hemorrhage (SAH), brainstem compression, or ischemia. In any instance, the prognosis seems poorer than that for vertebral artery (VA) dissection. The authors analyzed clinical presentations and radiological features of BA dissection with and without rupture.

Methods. Between 1998 and 2003, the authors treated 10 patients (eight men and two women, ranging in age from 32–78 years; mean age 54 years) with BA dissection. Diagnosis was based on clinical and radiological findings, including those from magnetic resonance imaging and cerebral angiography studies.

Of the 10 patients, five had impaired consciousness at disease onset. Among four patients presenting with SAH, two were treated conservatively and had fair outcomes without recurrent hemorrhage. The other two patients with SAH were treated using unilateral endovascular VA occlusion, but one of them subsequently suffered fatal rebleeding. A fifth patient presented with progressive signs of a mass involving the brainstem, whereas the remaining five patients showed brainstem ischemia; all were treated conservatively. Four patients could not return to their previous daily activities.

Conclusions. Basilar artery dissections are rare lesions associated with significant morbidity and death. The natural course of and the treatment options for BA dissection differ considerably from those for VA dissections. Management of these lesions is controversial and difficult, and requires particular care.

Successful treatment of a ruptured dissecting basilar artery aneurysm

✓ Dissecting basilar artery (BA) aneurysms in patients presenting with subarachnoid hemorrhage are life threatening, especially in those who experience subsequent bleeding or progressive dissection, and immediate surgical or endovascular intervention may be necessary. The authors report on a 52-year-old woman whose dissecting BA aneurysm was treated successfully with proximal occlusion and flow reversal. Clipping of the proximal BA above the level of the anterior inferior cerebellar arteries facilitated retrograde flow from a radial artery graft placed between the left vertebral artery and the left posterior cerebral artery, thereby providing continuous perfusion of the BA and its branches. Postoperative angiograms obtained 1 year later revealed good retrograde flow through the BA and dilation of the radial arterial graft. There were no episodes of recurrent hemorrhage.

Ischemic Basilar Artery Dissecting Aneurysm Treated by Stenting Only-Case Report-

A 45-year-old man presented with enlargement of basilar artery dissecting aneurysm 10 months after suffering brain stem infarction. Combined stenting and placement of Guglielmi detachable coils (GDCs) was planned to obliterate the aneurysm sac. Stent deployment was performed but the procedure was halted to avoid overdosing with contrast material. Cerebral angiography 10 days later showed thrombosis of the aneurysm sac and normalization of the blood flow in the basilar artery. The patient has been followed up for 2 years and showed good clinical and angiographic outcome. Stenting results in obliteration of the aneurysm sac, so a two-stage procedure is recommended.

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.

Significance of a small bulge on the basilar artery in patients with perimesencephalic nonaneurysmal subarachnoid hemorrhage. Report of two cases

Perimesencephalic nonaneurysmal subarachnoid hemorrhage (SAH) is a distinct type of hemorrhage with a characteristic bleeding pattern and an excellent clinical outcome. The cause of this benign form of SAH remains unknown. The authors report on two cases of perimesencephalic nonaneurysmal SAH in which a small bulge on the basilar artery (BA) was demonstrated on three-dimensional rotational angiography studies. Based on data from these cases, one may infer that the lesion on the BA is responsible for the SAH. The possible pathogenesis is discussed.

Dissecting basilar artery aneurysm growing during long-term follow up--case report

A 58-year-old male presented with a dissecting aneurysm of the basilar artery manifesting as dysarthria, left hemiparesis, and numbness of the left side. Angiography revealed a double lumen at the midportion of the basilar artery which was consistent with a diagnosis of dissecting basilar artery aneurysm. The patient was treated conservatively, and remained neurologically stable for a 5-year period following initial presentation, but serial magnetic resonance imaging revealed growth of the aneurysm compressing the brain stem. His condition then worsened. Computed tomography revealed obstructive hydrocephalus. Ventriculoperitoneal shunting was performed and the patient's symptoms improved. However, he died of subarachnoid hemorrhage. Autopsy showed the patient had had a type 3 "dolichoectatic dissecting aneurysm." Surgical treatment should be seriously considered for treating the patients with dissecting basilar artery aneurysm causing brain stem ischemia, especially if the aneurysm is growing. High-flow bypass and proximal occlusion may be the choice in patients with poor collateral circulations.

Subarachnoid hemorrhage from vertebrobasilar dissecting aneurysm treated with staged bilateral vertebral artery occlusion: the importance of early follow-up angiography: technical case report

OBJECTIVE AND IMPORTANCE

Vertebrobasilar dissecting aneurysms are an uncommon but increasingly recognized cause of subarachnoid hemorrhage (SAH). We describe a patient with SAH caused by a dissecting aneurysm involving both vertebral arteries as well as the basilar trunk. The patient was treated successfully with proximal occlusion of the vertebral arteries using endovascular balloon occlusion in two stages. The importance of early follow-up angiography to document progression or resolution of untreated dissections is emphasized. This approach is suggested as definitive treatment for vertebrobasilar dissection in appropriate circumstances.

CLINICAL PRESENTATION

A 41-year-old man presented with SAH from spontaneous vertebrobasilar dissection. Angiography revealed aneurysmal dilation of the right vertebral artery and basilar trunk and occlusion of the left vertebral artery.

INTERVENTION

The dissecting aneurysm was treated with balloon occlusion of the right vertebral artery. Repeat angiography 2 weeks later demonstrated resolution of the left vertebral occlusion, with restoration of antegrade flow in the basilar trunk and increased filling of the right vertebral and basilar dissecting aneurysms. Balloon occlusion of the left vertebral artery led to aneurysm thrombosis and excellent clinical outcome.

CONCLUSION

Bilateral vertebrobasilar dissecting aneurysms are an uncommon cause of SAH. If unilateral proximal vertebral artery occlusion is chosen as the initial treatment, it is essential to document the status of the contralateral vessel using follow-up angiography. Staged bilateral vertebral artery occlusion should be considered in the event of recurrent or progressive aneurysm enlargement. Endovascular balloon occlusion has advantages over proximal clipping of the parent vessel: cranial nerve manipulation is avoided, test occlusion in the awake patient can be performed at the site of permanent occlusion, and therapeutic levels of anticoagulation can be maintained throughout and after the procedure, thus diminishing the likelihood of thromboembolic complications.

Risk factors and precipitating neck movements causing vertebrobasilar artery dissection after cervical trauma and spinal manipulation

STUDY DESIGN

Potential precipitating events and risk factors for vertebrobasilar artery dissection were reviewed in an analysis of the English language literature published before 1993.

OBJECTIVES

To assess the literature pertaining to precipitating neck movements and risk factors for vertebrobasilar artery dissection in an attempt to determine whether the incidence of these complications can be minimized.

SUMMARY OF BACKGROUND DATA

Vertebrobasilar artery dissection and occlusion leading to brain stem and cerebellar ischemia and infarction are rare but often devastating complications of cervical, manipulation and neck trauma. Although various investigators have suggested potential risk factors and precipitating events, the basis for these suggestions remains unclear.

METHODS

A detailed search of the literature using three computerized bibliographic databases was performed to identify English language articles from 1966 to 1993. Literature before 1966 was identified through a hand search of Index Medicus. References of articles obtained by database search were reviewed to identify additional relevant articles. Data presented in all articles meeting the inclusion criteria were summarized.

RESULTS

The 367 case reports included in this study describe 160 cases of spontaneous onset, 115 cases of onset after spinal manipulation, 58 cases associated with trivial trauma, and 37 cases caused by major trauma (3 cases were classified in two categories). The nature of the precipitating trauma, neck movement, or type of manipulation that was performed was poorly defined in the literature, and it was not possible to identify a specific neck movement or trauma that would be considered the offending activity in the majority of cases. There were 208 (57%) men and 158 (43%) women (gender data not reported in one case) with an average age of 39.3 +/- 12.9 years. There was an overall prevalence of 13.4% hypertension, 6.5% migraines, 18% use of oral contraception (percent of female patients), and 4.9% smoking. In only isolated cases was specific vascular disease such as fibromuscular hyperplasia noted.

CONCLUSIONS

The literature does not assist in the identification of the offending mechanical trauma, neck movement, or type of manipulation precipitating vertebrobasilar artery dissection or the identification of the patient at risk. Thus, given the current status of the literature, it is impossible to advise patients or physicians about how to avoid vertebrobasilar artery dissection when considering cervical manipulation or about specific sports or exercises that result in neck movement or trauma.

Treatment of dissecting basilar artery aneurysm by flow reversal

Dissecting aneurysm of the basilar artery is a rare but increasingly recognized entity, with a frequently fatal or morbid outcome. Unlike the well established proximal occlusion and trapping approaches to vertebral artery dissections, surgical intervention for basilar lesions has been limited to wrapping techniques for arterial wall reinforcement. We report a case of midbasilar dissecting aneurysm successfully treated by clipping the proximal basilar artery below the level of the anterior inferior cerebellar arteries, allowing retrograde flow via the posterior communicating arteries to provide continued basilar perfusion. With the growing recognition of basilar dissection and pseudoaneurysm formation there is a need for improved therapeutic options. We suggest that definitive treatment can be achieved using the principle of proximal occlusion and flow reversal, and review the pertinent literature on basilar artery dissection.

Recurrent subarachnoid hemorrhage from untreated ruptured vertebrobasilar dissecting aneurysms

The clinical characteristics of vertebrobasilar dissecting aneurysms occurring with subarachnoid hemorrhage (SAH) were reviewed in 42 patients, with particular focus on the time, incidence, and outcome in association with subsequent rupture. Twenty-nine patients underwent 31 surgical procedures, and the remaining 13 patients were managed without surgery. Surgical details included 19 proximal vertebral artery obliterations (including 1 case of endovascular surgery using balloon occlusion), 9 trappings, 1 wrapping, 1 bleb clipping, and 1 bleb clipping combined with wrapping. Surprisingly, subsequent rupture occurred in 30 (71.4%) of the 42 patients. Excluding one patient with postoperative rupture, 29 patients suffered a subsequent rupture in the unsecured stage. Of these 29 patients, 19 were operated on after the subsequent rupture and 10 were not operated on because of deteriorated clinical condition (9 patients) or anatomic considerations (1 patient). Of the 30 patients that suffered a subsequent rupture, 14 died. Twelve of the deaths were directly related to the second episode of rupture. Of the 12 patients who did not suffer a subsequent rupture, 10 underwent operations and there were no operative deaths. Only one patient died as the result of the initial critical SAH. The mortality (46.7%) of the patients with subsequent rupture was significantly higher (P < 0.05) than that (8.3%) of the patients without subsequent rupture. Seventeen (56.7%) of the 30 subsequent ruptures occurred within 24 hours after the first SAH, and 24 (80%) occurred within the first week. Six (66.7%) of the 9 patients operated on within 24 hours after the first SAH and 11 (68.8%) of the 16 patients operated on within a week suffered preoperative subsequent ruptures.(ABSTRACT TRUNCATED AT 250 WORDS)

Dissecting aneurysms of the basilar artery

Ten patients (six men and four women; mean age, 40 yr) with spontaneous dissection of the basilar artery are reported. Clinically, six were admitted with subarachnoid hemorrhage (SAH) and four were admitted with brain stem ischemia. Angiography demonstrated string sign in four patients, pearl reaction in four, double lumen in one, and arterial ectasia with mural retention of contrast medium in one. Magnetic resonance imaging was performed in two patients. Follow-up angiograms or magnetic resonance angiography in six patients showed spontaneous healing in two patients, improvement in two, progression in one, and no change in one. Nine patients were treated medically, and one underwent selective intravascular occlusion of the dissecting aneurysm. One patient died after further SAH, two remain severely disabled, three have residual neurological deficit, and four are in good clinical condition. The most interesting observations in this series include a relatively good course in a substantial number of patients and low further bleeding potential after SAH, the late "globular" evolution, which may be favorable for reconstructive treatment, and the diagnostic value of associated computed tomographic/angiographic findings. Surgical options in basilar dissection are very poor; in some reported cases, wrapping has been tried with disappointing results. In light of the possibility of spontaneous healing or improvement, wrapping should be reserved for only those patients with recurrent SAH or angiographic progression of the dissection.

Dissection of the vertebral arteries: case report and discussion

Vertebral artery dissection is an unusual condition with potentially protean neurologic presentations. It may occur spontaneously or follow apparently minor neck trauma. Ischemic symptoms related to the posterior circulation ensue and may be due to obstruction or embolization. The ensuing stroke is ischemic, although subarachnoid hemorrhage may be a complication as well. A case of vertebral artery dissection in a young woman who developed symptoms approximately one week after mild neck injury is reported, and the topic is reviewed.

A transcondylar approach to the arteriovenous malformation at the ventral cervicomedullary junction: report of three cases

Arteriovenous malformation at the cerevicomedullary junction is a rare disorder, usually presenting with subarachnoid hemorrhage. The diagnosis is difficult because of its anatomical location. In addition, the ventral location of these arteriovenous malformations makes surgical treatment difficult. We describe three cases surgically treated with a transcondylar approach. The usefulness of digital subtraction angiography and magnetic resonance imaging is discussed. The technique of the transcondylar approach is also described, including C1 hemilaminectomy, unroofing of the transverse foramen of C1 to obtain control of the vertebral artery, and partial resection of the occipital condyle and lateral atlantal mass by extradural drilling. This approach provides direct access to the ventral portion of the cervicomedullary junction.

Magnetic resonance imaging study of intracranial vertebrobasilar artery dissections

BACKGROUND AND PURPOSE

The purpose of this study is to demonstrate the magnetic resonance features of intracranial vertebrobasilar artery dissections and to determine the potential and limitations of magnetic resonance imaging in their diagnosis.

METHODS

We studied five consecutive patients with angiographically verified intracranial vertebrobasilar artery dissection with magnetic resonance imaging (0.5 T) in regard to the shapes of the intramural hematoma and the chronological change of its signal intensity. We also estimated the sensitivity of magnetic resonance imaging for diagnosing dissection.

RESULTS

We observed intramural hematoma in four patients on the first magnetic resonance scan and in all five patients during the course of the study. The shapes of the intramural hematomas were curvilinear, crescentic, "bamboo-cut," "band-like," and spotty. The intensity of the intramural hematoma varied according to its age. On the T1-weighted and the proton images, the intramural hematomas appeared isointense to slightly hyperintense in the first few days and became hyperintense thereafter. The intramural hematomas became isointense or unrecognizable 2 months after onset. The T1-weighted image and the proton images were superior to the T2-weighted image in demonstrating the intramural hematomas.

CONCLUSIONS

Magnetic resonance imaging is a sensitive tool for diagnosing intracranial vertebrobasilar artery dissection, particularly in the subacute to early chronic stage. Magnetic resonance imaging is complementary to angiography in that it can directly visualize intramural hematomas.

Unusual angiographic changes in a dissecting aneurysm of the basilar artery: case report

A patient with unusual angiographic changes of a dissecting aneurysm of the basilar artery is presented. Initial angiography and magnetic resonance imaging revealed a typical dissecting aneurysm. However, a follow-up study demonstrated a saccular aneurysmal dilatation of the proximal part of the dissection. The importance of the follow-up study, particularly in regard to the usefulness of magnetic resonance imaging and the pathogenesis of this change are discussed.

Dissecting aneurysms of the vertebrobasilar system: study of 16 cases

In the last 14 years we have encountered 16 patients with spontaneous intracranial dissections of the vertebrobasilar (VB) system (mean age was 46 years and male/female ratio was 10/6). VB dissections presented in eight cases with subarachnoid bleeding and in eight with brainstem, cerebellar, or cerebral ischemia. Three patients had multiple dissections. Ten dissections occurred in the vertebral artery (two extended to the basilar artery), three in the posterior cerebral artery (one bilateral), two in the basilar artery, and one in the posterior inferior cerebellar artery. The angiographic configuration included "string" sign, "pearl and string" sign, fusiform dilation, and double lumen. The following angiographic evolution (available in 11 cases) was that of complete healing (three cases), partial resolution (five cases), progression (one case), and unimproving (two cases). Three patients died (two due to recurrent subarachnoid hemorrhage): two patients were explored surgically (one had further intravascular therapeutic embolization), and the rest were treated conservatively. Not all dissecting aneurysms fared in the same manner, depending either on the location in the VB circulation or on the variable vascular configuration: treatment should be fitted to the timing of diagnosis.

Dissecting aneurysm of the posterior inferior cerebellar artery

Dissecting aneurysms of the posterior inferior cerebellar artery are an uncommon cause of stroke in the vertebrobasilar system, but they may also present with subarachnoid bleeding into the posterior fossa in 70% of the cases. Neither magnetic resonance imaging nor vertebral angiography show specific signs. Treatment should be neurosurgical to prevent rebleeding, although few cases have been reported. The authors report a tenth case and the literature is reviewed.

A pathological study of intracranial posterior circulation dissecting aneurysms with subarachnoid hemorrhage: report of three autopsied cases and review of the literature

Three autopsied cases of dissecting aneurysms with spontaneous subarachnoid hemorrhage of the intracranial posterior circulation are reported, and the literature is reviewed to investigate the pathological characteristics and pathogenesis of this lesion. The location and pathological features of the aneurysms were different in each of the cases presented. Subadventitial hemorrhage associated with the subarachnoid hemorrhage, multiple noncontiguous intramural hemorrhages, and new vessels in and around the arterial wall were noteworthy findings in our series. All 20 reported autopsied cases of the vertebrobasilar artery have a dissection between the media and adventitia with a rupture site in the thin adventitia. Seventeen of them had disruption of the entire arterial wall, but the remaining three cases had no apparent luminal connection. The clinicopathological features of this disease are various. On the basis of the pathological investigations of these reported cases, the pathogenesis of this lesion is discussed. Intramural hemorrhage associated with dissection without luminal connection should not be disregarded as a causative factor.

Intracerebral hemorrhage caused by transmural dissection of the anterior cerebral artery

BACKGROUND AND PURPOSE

Spontaneous dissection of the intracranial carotid artery or its main branches is an unusual condition.

CASE DESCRIPTION

A 72-year-old hypertensive woman after an intense nuchal rigidity showed a subarachnoid hemorrhage and an interhemispheric hematoma by computed tomography. The neuropathological study revealed a transmural dissection of the pericallosal artery.

CONCLUSIONS

The authors suggest that the dissection origin is an atheromatous plaque that bleeds, producing a dissection plane from the lumen to the adventitial artery.

Distal ligation and revascularization from external carotid to vertebral artery with radial artery graft for treatment of extracranial vertebral artery dissection. Report of a case

We present a case of dissection of the extracranial vertebral artery with prominent occipital pain and elements of the lateral medullary syndrome. Arteriography showed a string and pearl sign. Magnetic resonance imaging allowed visualization of an intramural thrombus associated with a narrow vascular lumen. The distal portion of the diseased artery was ligated and vascular reconstruction using an interposed radial artery graft was performed. Pathological studies confirmed the diagnosis. The diagnostic roles of angiography and magnetic resonance imaging, and therapeutic strategies are discussed.

Distal ligation and revascularization from external carotid to vertebral artery with radial artery graft for treatment of extracranial vertebral artery dissection. Report of a case

We present a case of dissection of the extracranial vertebral artery with prominent occipital pain and elements of the lateral medullary syndrome. Arteriography showed a string and pearl sign. Magnetic resonance imaging allowed visualization of an intramural thrombus associated with a narrow vascular lumen. The distal portion of the diseased artery was ligated and vascular reconstruction using an interposed radial artery graft was performed. Pathological studies confirmed the diagnosis. The diagnostic roles of angiography and magnetic resonance imaging, and therapeutic strategies are discussed.