Non-traumatic dissecting aneurysms of the intracranial vertebral artery. Report of six cases

Therapeutic occlusion of the vertebral artery using a new penumbra occlusion device system and ruby coils (penumbra): A technical note

There are several methods to achieve the therapeutic sacrifice of the vessel, coiling brings the most commonly used. Penumbra occlusion device (POD) system is a newer modality for therapeutic large vessel occlusion, and it is the Food and Drug Administration approved only for peripheral vessels. We report a case where therapeutic vertebral artery (VA) occlusion was achieved with the POD system and Ruby coils for the first time. A patient was diagnosed with a new malignant-appearing tumor of the cervical spine. A conventional angiogram showed multiple tiny arterial feeders from the VA beyond scope of coil/onyx embolization, so we performed a balloon occlusion test followed by therapeutic sacrifice of the VA. A successful VA occlusion was achieved with significant reduction in the tumor blush, followed by open resection of the tumor. The patient had favorable postoperative course and without any neurological symptoms attributed to the VA occlusion.

Single-stage endovascular treatment of subarachnoid hemorrhage related to bilateral vertebral artery dissecting aneurysms

OBJECTIVE

Treatment of bilateral vertebral artery dissecting aneurysms presenting with subarachnoid hemorrhage remains challenging as bilateral deconstructive procedures may not be feasible. In this case series, we describe our approach to their management and review the pertinent literature.

METHOD

A retrospective review of our prospectively collected database on aneurysms was performed to identify all patients with acute subarachnoid hemorrhage in the setting of bilateral intradural vertebral artery dissections (VAD) encompassing a period from January 2000 and March 2012.

RESULT

Four patients (M/F = 2/2; mean age, 51.5 years) were identified. In two cases the site of rupture could be identified by angiographic and cross-sectional features; in these patients deconstructive treatment (proximal obliteration or trapping) of the ruptured site and reconstructive treatment of the unruptured site (using stents and coils) were performed. In the patients in whom the site of hemorrhage could not be determined, bilateral reconstructive treatment was performed. No treatment-related complications were encountered. Modified Rankin scale scores were 0-1 at discharge, and on follow-up (mean 63 months), no recurrence, in-stent thrombosis or new neurological deficits were encountered.

CONCLUSION

We believe that single-stage treatment in patients with bilateral VAD is indicated: If the site of hemorrhage can be determined, we prefer deconstructive treatment on the affected site and reconstructive treatment on the non-affected site to prevent increased hemodynamic stress on the unruptured but diseased wall. If the site of dissection cannot be determined, we prefer bilateral reconstructive treatment to avoid increasing hemodynamic stress on the potentially untreated acute hemorrhagic dissection.

Permanent endovascular balloon occlusion of the vertebral artery as an adjunct to the surgical resection of selected cervical spine tumors: A single center experience

BACKGROUND AND PURPOSE

Complete surgical resection of cervical spine tumors is often challenging when there is tumor encasement of major neck vessels. Pre-operative endovascular sacrifice of the major vessels can facilitate safe tumor resection. The use of transarterial detachable coils has been described in this setting, but it can be time-consuming and costly to occlude a patent parent vessel using this method. Our aim was to evaluate the safety and effectiveness of our endovascular detachable balloon occlusion technique, performed without prior balloon test occlusion in the pre-operative management of these tumors.

METHODS

We retrospectively reviewed 18 consecutive patients undergoing pre-operative unilateral permanent endovascular balloon occlusion of tumor-encased vertebral arteries in our institution. Procedure-related ischemic or thromboembolic complication was defined as focal neurologic deficit attributable to the endovascular occlusion which occurs before subsequent surgical resection.

RESULTS

Successful pre-operative endovascular vertebral artery sacrifice using detachable balloons was achieved in 100% (n = 18) of cases without prior balloon test occlusion. Procedural complication rate was 5.6% as one patient developed transient focal neurology secondary to a delayed cerebellar infarct at home on day 11 and subsequently made a full recovery. There were no cases of distal balloon migration. Complete macroscopic resection of tumor as reported by the operating surgeon was achieved in 89% of cases.

CONCLUSION

Pre-operative endovascular sacrifice of the vertebral artery using detachable balloons and without prior balloon test occlusion is a safe procedure with low complication rates and good surgeon reported rates of total resection.

Republished: Monotherapy with stenting in subarachnoid hemorrhage (SAH) after middle cerebral artery dissection

Isolated middle cerebral artery dissection is a rare clinical entity, with descriptions limited to a few case reports and case series. Symptomatic dissection in the anterior circulation can present as an ischemic stroke in a young population; however, it is rarely associated with subarachnoid hemorrhage. We describe a young patient who presented with acute headache from a subarachnoid hemorrhage that was ultimately determined to be due to a vascular dissection in the middle cerebral artery. The initial angiogram showed vascular irregularities in this area with stenosis. Repeat imaging 4 days after presentation identified a pseudoaneurysm proximal to the stenosis. The patient was successfully treated with a self-expanding nitinol stent and followed up with serial angiography during postoperative recovery in the hospital; additional angiograms were performed approximately 1 and 6 months after treatment. Serial angiograms demonstrated incremental healing of the dissection. The patient was discharged and remains neurologically intact at the 6-month follow-up.

Monotherapy with stenting in subarachnoid hemorrhage (SAH) after middle cerebral artery dissection

Isolated middle cerebral artery dissection is a rare clinical entity, with descriptions limited to a few case reports and case series. Symptomatic dissection in the anterior circulation can present as an ischemic stroke in a young population; however, it is rarely associated with subarachnoid hemorrhage. We describe a young patient who presented with acute headache from a subarachnoid hemorrhage that was ultimately determined to be due to a vascular dissection in the middle cerebral artery. The initial angiogram showed vascular irregularities in this area with stenosis. Repeat imaging 4 days after presentation identified a pseudoaneurysm proximal to the stenosis. The patient was successfully treated with a self-expanding nitinol stent and followed up with serial angiography during postoperative recovery in the hospital; additional angiograms were performed approximately 1 and 6 months after treatment. Serial angiograms demonstrated incremental healing of the dissection. The patient was discharged and remains neurologically intact at the 6-month follow-up.

Safety of unilateral endovascular occlusion of the cervical segment of the vertebral artery without antecedent balloon test occlusion

BACKGROUND AND PURPOSE

Antecedent balloon test occlusion is often performed prior to vertebral artery sacrifice, but there is limited data to suggest this adds a significant clinical benefit, especially in the setting of trauma. Furthermore, balloon test occlusion can be time-consuming, add to the technical complexity of the procedure, and increase the overall cost of treatment. The purpose of this study was to determine the safety of unilateral vertebral artery occlusion without antecedent balloon test occlusion as part of the treatment regimen in patients with traumatic vertebral artery dissection, cervical tumor, or intracranial aneurysm.

MATERIALS AND METHODS

The medical records and imaging studies of 59 patients in whom unilateral endovascular cervical vertebral artery occlusion was performed were retrospectively reviewed. Procedure-related stroke was defined as imaging evidence of acute infarct in the vascular territories supplied by the occluded vertebral artery or new focal neurologic deficit developing in the first 30 days after vertebral artery occlusion attributable to infarction in the posterior circulation.

RESULTS

Fifty-nine patients underwent unilateral endovascular cervical vertebral artery occlusion to prevent potential thromboembolic complications of vertebral artery injury, for treatment of intracranial aneurysms, or for presurgical embolization of a cervical vertebral tumor. Unilateral occlusion was performed when endovascular reconstruction was considered impossible or deemed more risky than deconstruction. Fifty-eight of the 59 patients underwent vertebral artery occlusion without antecedent balloon test occlusion. None of the 59 patients had clinical or imaging evidence of a postprocedural infarct.

CONCLUSIONS

In this series, endovascular occlusion of a cervical segment of 1 vertebral artery was safely performed without antecedent balloon test occlusion. As long as both vertebral arteries were patent and converged at the vertebrobasilar junction, there was anatomic potential for retrograde filling of the distal intracranial vertebral artery to the level of the posterior inferior cerebellar artery origin, and there was no major vascular supply to the spinal cord arising from the target segment of the affected vessel. Dominant and nondominant vertebral arteries were safely occluded, and no infarcts were attributed to the treatment.

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.

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.

Spontaneous dissecting aneurysm of the intracranial vertebral artery: management strategies

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Endovascular treatment of ruptured posterior circulation dissecting aneurysms

BACKGROUND

and aim: Dissecting aneurysms of the posterior circulation constitute a relatively uncommon subgroup of aneurysms. They account for 3-7% of cases of nontraumatic subarachnoid hemorrhage. Because of high risk, in most cases the patients require surgical or endovascular therapy. In this study we discuss the clinical efficacy of endovascular treatment with long-term follow-up in ruptured dissecting aneurysms of the posterior circulation.

MATERIALS AND METHODS

This retrospective study was conducted at our institution between January 1995 and June 2005. Eight patients (4 male; 4 females) ranging in age from 24 to 65 years (mean, 46.75 years), were included. All presented with SAH. Endovascular treatment was based on the configuration of the dissecting aneurysm. Attempt was made to occlude the dissecting aneurysm.

RESULT

A total of 8 ruptured dissecting aneurysms in the posterior circulation were treated. Out of them 5 were in the intradural vertebral artery, 2 in the basilar trunk and one in the proximal PCA. All the cases were technically successful. We have seen only two complications. The pre and post procedure (at the time of discharge) mean modified Rankin scores in the patients were 4.6 (SD 0.51) and 1.7 (SD 1.98). This improvement in Rankin score after endovascular treatment was statistically significant (Wilcoxon signed rank test, P=.017).

CONCLUSION

Endovascular management of these lesions is safe and effective mode of treatment and gives adequate protection from rebleed.

Endovascular management of vertebrobasilar dissecting aneurysms

BACKGROUND AND PURPOSE

Several approaches to the treatment of dissecting aneurysms of the vertebrobasilar system have been used. We evaluated our endovascular experience, which includes trapping and proximal occlusion.

METHODS

Thirty-five patients with intradural vertebrobasilar dissecting aneurysms presented to our institution between 1992 and 2002. Twenty-six were treated by endovascular means and two with surgery. In the endovascular group, 14 were in a supra-posterior inferior cerebellar artery (PICA) location, and three of these extended to the vertebrobasilar junction on the initial angiogram. Ten were located in an infra-PICA location, or no antegrade flow was seen in the PICA or anterior spinal artery. Two were located at the PICA with antegrade flow preserved in the branch. Twelve lesions were treated with trapping; another 14 were initially treated with proximal occlusion techniques, two of which eventually required trapping procedures. Follow-up images were obtained within 1 year of initial treatment in 24 patients. Mean follow-up for these patients was 3.5 years.

RESULTS

Initial treatments were technically successful and without complication in all 26 patients. Follow-up examinations showed complete cure in 19 of 24 patients. One patient died of global ischemia after presenting as Hunt and Hess grade 5 with subarachanoid hemorrhage. Two recurrent hemorrhages occurred in patients in the proximal occlusion group; one died, and the other underwent a trapping procedure. One patient developed contralateral vertebral dissection 24 hours after occlusion of a dissecting aneurysm of the dominant vertebral artery and died of a brain stem infarct. Another died of probable vasospasm, and the last died of an unknown cause 1 month after treatment. Two patients had recanalization despite an initial trapping procedure, both underwent further treatment. Mortality rate was 20% in the treated group (including the two patients treated surgically), with four of five deaths occurring during the initial hospital course. Mortality rate was 50% in the six patients in the untreated group who were available for follow-up.

CONCLUSION

Dissecting aneurysms of the vertebrobasilar system remain high-risk lesions because of their natural history. They can be managed by endovascular methods according to aneurysm location, configuration, collateral circulation, and time of presentation. Trapping results in better prevention of rehemorrhage. Proximal occlusion can achieve occlusion without manipulation of the affected segment when more direct endovascular occlusion or stent placement cannot be performed.

The efficacy of coil embolization at the dissection site of ruptured dissecting vertebral aneurysms

SUMMARY

Proximal occlusion of the parent artery has been widely used for treatment of vertebral dissecting ruptured aneurysms, but this does not always completely prevent re-rupture. In this series, the efficacy of occlusion at the dissection site using detachable coils was compared with proximal balloon occlusion. Over a five year period, 25 patients suffering from subarachnoid hemorrhage with dissecting vertebral aneurysms were treated by endovascular surgery. The first three of these 25 patients were treated with proximal balloon occlusion of the parent artery. The remainder underwent platinum coil occlusion at the affected site as early as possible after the diagnosis. In two of the three cases treated with proximal balloon occlusion, clipping or coating surgery were added because of progressive dissection. In all 22 cases of coil embolization, the intervention was successfully performed without complication. In one case with a dissection involving bilateral vertebral arteries, minor rebleeding from a contralateral dissection occurred after embolization. In the other 21 cases, rebleeding was not apparent (clinical follow-up: mean 24 months). Radiological findings showed complete occlusion of the dissection site and patency of the non affected artery (follow-up: mean ten months). We conclude that detachable platinum coil embolization at the dissection site is more effective than proximal occlusion for treatment of ruptured vertebral dissecting aneurysms because of immediate cessation of blood flow to the dissection site. However, in cases with bilateral dissections or hypoplastic contralateral vertebral arteries, preceding bypass surgery or stent treatment to preserve the affected vertebral artery may be needed.

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

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

METHODS

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

CONCLUSIONS

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

Coil Embolization for Ruptured Dissection on the Vertebral Artery Distal to the Origin of Posterior Inferior Cerebellar Artery

Although many surgical or endovascular treatments for ruptured vertebral dissection have been reported, the best treatment remains controversial. Recently endovascular vertebral occlusion using coils has been reported, the appropriate occlusion site has not yet been fully discussed.

Five cases of ruptured vertebral dissection located distally to the origin of posterior inferior cerebellar artery were occluded by platinum coil packing in the angiographical “pearl” portion or “fusiform dilatation” together with its proximal vertebral artery. All dissections were occluded completely together with occlusion of distal portion of vertebral artery to PICA's origin. No complications related to procedure were seen in this series.

Occlusion of rupture point with preserving tiny perforators arising from vertebral artery would be an ideal method for this lesion. The present cases suggest that the short segment occlusion by coil packing in the angiographical “pearl” portion or “fusiform dilatation” together with its proximal vertebral artery would be near to the ideal.

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.

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

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

Intracranial dissecting aneurysm causing subarachnoid hemorrhage: the role of computerized tomographic angiography and magnetic resonance angiography

BACKGROUND

With increasing frequency, dissecting aneurysms of the intracranial arteries are recognized as a possible cause of subarachnoid hemorrhage (SAH). In the presence of a dissecting aneurysm, angiographic changes may be subtle at presentation and correct diagnosis often requires serial angiograms. We report a patient with a dissecting aneurysm of the anterior cerebral artery (ACA) causing SAH, in whom less invasive diagnostic tools, such as high-resolution computerized tomographic angiography (CTA) and magnetic resonance angiography (MRA), were helpful in confirming the diagnosis and in following the evolution of the dissection.

CASE PRESENTATION

We present this 51-year old woman who experienced the sudden onset of severe headache without associated neurological deficits. Head CT showed SAH with blood in the interhemispheric fissure, suggesting a ruptured ACA aneurysm. Serial cerebral angiograms failed to demonstrate an aneurysmal sac, but showed evolving irregularities of the ACA consistent with a dissecting aneurysm. These findings were confirmed by CTA and MRA. The patient was treated conservatively and made an excellent recovery. A MRA obtained 2 months later showed slight improvement of the previously visualized ACA dilatation.

CONCLUSION

Serial angiograms are often required to confirm the diagnosis and to follow the evolution of an intracranial dissection. With recent advances in neuroradiological techniques, however, critical information can be obtained by less invasive imaging studies, such as CTA and MRA.

Tissue plasminogen activator in a vertebral artery dissection

BACKGROUND

Spontaneous dissection of the vertebral artery is uncommon.

METHOD

Case study.

RESULTS

We report a 49-year-old woman who presented with the rapidly progressing basilar artery syndrome who was given an intravenous dose of tissue plasminogen activator seven hours after the onset of first symptoms. Thirty minutes after the injection, a dramatic recovery of the patient's consciousness and neurological signs was noted.

CONCLUSION

To our knowledge, this is the first reported case of intravenous tissue plasminogen activator use in acute vertebral artery dissection.

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.

Spontaneous vertebral dissection: clinical, conventional angiographic, CT, and MR findings

OBJECTIVE

The purpose of this study was to determine if typical clinical and neuroradiologic patterns exist in patients with spontaneous vertebral artery (VA) dissection.

MATERIALS AND METHODS

The medical records and neuroradiologic examinations of 14 patients with spontaneous VA dissection were reviewed. The medical records were examined to exclude patients with a history of trauma and to record evidence of a nontraumatic precipitating event ("trivial trauma") and presence of possible risk factors such as hypertension. All patients underwent conventional angiography, 13 either CT or MRI (11 both CT and MRI), and 3 MRA. Conventional arteriograms were evaluated for dissection site, evidence of fibromuscular dysplasia, luminal stenosis or occlusion, and pseudoaneurysm formation. CT examinations for the presence of infarction or subarachnoid hemorrhage. MR examinations for the presence of infarction or arterial signal abnormality, and MR angiograms for abnormality of the arterial signal column.

RESULTS

Seven patients had precipitating events within 24 h of onset of symptoms that may have been causative of dissection and five had hypertension. At catheter angiography, two patients had dissections in two arteries (both VAs in one patient, VA and internal carotid artery in one patient), giving a total of 15 VAs with dissection. Dissection sites included V1 in four patients, V2 in one patient, V3 in three patients, V4 in six patients, and both V3 and V4 in one patient. Luminal stenosis was present in 13 VAs, occlusion in 2, pseudoaneurysm in 1, and evidence of fibromuscular dysplasia in 1. Posterior circulation infarcts were found on CT or MR in five patients. Subarachnoid hemorrhage was found on CT in two patients and by lumbar puncture alone in two patients. Abnormal periarterial signal on MRI was seen in three patients. MRA demonstrated absent VA signal in one patient, pseudoaneurysm in one, and a false-negative examination in one. Repeat catheter angiography of nine VAs at an interval ranging from 2 weeks to 1 year showed progression to occlusion in two arteries, unchanged appearance in 4, and angiographic resolution in three, which did not closely correlate with clinical outcome.

CONCLUSION

No preferred site of dissection along the course of the VA was found in this study. CT and MR examinations of the head are frequently normal in patients with VA dissections. No correlation between clinical outcome and findings at repeat angiography was demonstrated.

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)

Proximal balloon occlusion for dissecting vertebral aneurysms accompanied by subarachnoid hemorrhage

Five patients with spontaneous dissecting vertebral aneurysms presenting with subarachnoid hemorrhage were treated with endovascular proximal balloon occlusion after a successful balloon Matas' test. Occlusion was performed in the extracranial portion of the vertebral artery after the potentially dangerous period of cerebral vasospasm. Two patients rebled preoperatively during the waiting period. Although angiograms demonstrated residual aneurysmal dilatation for four of the five patients, postoperative hemorrhages or progression of the dissection were not observed during the 19- to 48-month follow-up period. Only one patient experienced transient postoperative ischemic complication. Although the timing of the procedure and the site of occlusion remain controversial, proximal balloon occlusion of the vertebral artery appears to be a safe and effective therapy for patients with dissecting vertebral aneurysms presenting with subarachnoid hemorrhages. This method provides an important, less invasive alternative for this condition.

Intracranial vertebral artery dissections: clinical, radiological features, and surgical considerations

We reviewed 24 patients with intracranial vertebral artery dissections treated during the last 12 years. Sixteen patients were admitted with subarachnoid hemorrhage (SAH) and 8 did not have SAH. The mean age at the time of onset was 50.0 years. Male preponderance was noted. Among 21 patients with acute onset, 6 (29%) experienced prodromal neck pain and 3 (60%) of 5 SAH patients showed nuchal stiffness when examined within 6 hours of onset. The preoperative angiographical findings were uniform in SAH cases in contrast to the varied angiographical findings seen in non-SAH cases. So-called pearl and string sign was observed in most SAH cases, but the "string" was often so short and wide that the term "constriction" appeared more suitable. From intraoperative observations, the angiographical point of constriction seemed to represent the proximal or distal end of dissection. As for treatment, 19 patients underwent 20 surgeries. Trapping was performed in eight surgeries, base clipping was performed in five, and proximal clipping was performed in seven. Both trapping and base clipping prevented further bleeding, but trapping was associated with a high rate of postoperative lower cranial nerve palsy. Postoperative neurological complications were less frequent after proximal clipping, but subsequent postoperative bleeding occurred in one patient treated by this technique. The overall long-term outcome in the surgically treated cases in our series was favorable, but most patients suffered from various degrees of uncomfortable dysphagia or hoarseness for some period after surgery. It was also noted that, in half of the disabled cases, the major disability was attributable to lower cranial nerve palsy and respiratory troubles that developed postoperatively.

Nonsurgical treatment of unruptured intracranial vertebral artery dissection with serial follow-up angiography

The question of whether unruptured intracranial vertebral artery dissections should be treated surgically or nonsurgically still remains unresolved. In this study, six consecutive patients with intracranial vertebral artery dissection presenting with brain-stem ischemia without subarachnoid hemorrhage (SAH) were treated non-surgically with control of blood pressure and bed rest, and five received follow-up review with serial angiography. No further progression of dissection or associated SAH occurred in any of the cases, and all patients returned to their previous lifestyles. In the serial angiograms in five patients, the findings continued to change during the first few months after onset. Four cases ultimately showed "angiographic cure," while fusiform aneurysmal dilatation of the affected vessel persisted in one case. In one patient, arterial dissection was visualized on the second angiogram despite negative initial angiographic findings. These results indicate that intracranial vertebral artery dissection presenting without SAH can be treated nonsurgically, with careful angiographic follow-up monitoring. Persistent aneurysmal dilatation as a sequela of arterial dissection seemed to form a subgroup of fusiform aneurysms of the posterior circulation. These aneurysms may be prone to late bleeding and may require surgical treatment.

Extracranial-intracranial saphenous vein bypass for carotid or vertebral artery dissections: a report of six cases

The management of carotid or vertebral artery dissections has generally been either conservative (with anticoagulation) or surgical (by proximal ligation or trapping procedures). However, identification and management of those patients with a high risk of stroke recurrence have been difficult. Six patients with carotid or vertebral artery dissections underwent a total of seven surgical procedures involving intracranial interpositional saphenous vein bypass grafts anastomosed distally beyond the point of dissection with trapping of the intermediate diseased section of the artery. It is suggested that this procedure be used in patients who have bilateral carotid or vertebral artery disease, persistent angiographic abnormalities (particularly aneurysms), or recurring ischemic events while undergoing anticoagulation therapy, or in whom anticoagulation is undesirable. This procedure has benefits over current surgical options because of the maintenance of high flow, the avoidance of abnormal watershed areas of flow, and the elimination of the risk of emboli. The procedure is compared to previous techniques of extracranial-intracranial bypass.

Repeat angiography and magnetic resonance imaging (MRI) of dissecting aneurysms of the intracranial vertebral artery. Report of four cases

We here present 4 cases with dissecting aneurysm (DA) of the intracranial vertebral artery, who were followed up by repeat cerebral angiography and MRI. The patients consisted of 2 males and 2 females, and the mean age was 43 years. Two cases were associated with polyarteritis nodosa (PN) and hypertension, respectively. Three of the cases developed subarachnoid haemorrhage (SAH), while the other one suffered from lateral medullary syndrome. In cerebral angiography, "pearl and string" signs were revealed in all cases, while a "double lumen" indicating a true diagnostic sign of DA was demonstrated in only one case. Repeat angiography showed that a bleb formation with a bulging of the aneurysmal sac was seen in 2 cases, and an irregularity of the wall in one case. On the other hand in one case, the ectatic part shrank, while the stenotic part was restored. In magnetic resonance imaging (MRI), a hyperintensity mass on T 1-weighted image (T 1-WI) adjacent to flow void suggesting either an intramural haematoma or a linear shape hyperintensity on T 1-WI were demonstrated in 3 cases. In the follow up MRI done in 2 cases, a serial change in the intensity from iso-intensity to hyperintensity on T 1-WI was observed in one case suggesting intramural haemorrhage, while an enlargement of the ectasic flow void was seen in the other case. Three of 4 cases were operated on by trapping of the aneurysms. One, who had systemic vascular diseases due to PN, and repeat angiography showed a regression of the aneurysm, was conservatively treated.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Recurrent ischemic events in two patients with painless vertebral artery dissection

BACKGROUND AND PURPOSE

Vertebral artery dissection causes endothelial changes and stenosis that may lead to recurrent ischemic neurological events. The diagnosis may not be obvious because the dissection may be painless and "spontaneous" (no obvious trauma). Magnetic resonance angiography has increasingly been used to screen patients for this disorder, but its accuracy has not yet been established.

CASE DESCRIPTION

Two patients were admitted with repeated transient ischemic attacks and strokes over 11 months and 1 month, respectively. Neither had a history of trauma, cervical pain, or headache. Magnetic resonance angiography failed to visualize vertebral artery dissections that were later revealed by conventional angiography. One patient's events were stopped by balloon occlusion of the vertebral artery proximal to the posterior inferior cerebellar artery branch.

CONCLUSIONS

Magnetic resonance angiography is not yet sensitive enough to always visualize vertebral artery dissection. Vertebral artery dissection is a life-threatening condition that requires aggressive evaluation and treatment.

Subarachnoid hemorrhage following spontaneous intracranial carotid artery dissection

Subarachnoid hemorrhage due to spontaneous dissection of intracranial vessels is uncommon. Most such cases are confined to the posterior circulation. Dissection of an intracranial carotid artery producing subarachnoid hemorrhage without a focal ischemic event is rarely documented. We report a case and review the subject.

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

A spontaneous dissecting aneurysm of the basilar artery is a rare disorder, usually presenting with ischemia rather than a subarachnoid hemorrhage (SAH). Two cases are described of a dissecting aneurysm of the basilar artery presenting with an SAH. Vertebral angiography revealed a double lumen to the basilar artery. Magnetic resonance (MR) imaging detected the intramural hematoma. One patient was treated conservatively, and the other underwent operative intervention with wrapping of the aneurysm. The usefulness of MR imaging in the diagnosis and the treatment options are discussed.