Tandem intracranial stent deployment for treatment of an iatrogenic, flow-limiting, basilar artery dissection: technical case report

Effectiveness of Intracranial Percutaneous Transluminal Angioplasty or Stenting for Atherosclerotic Vertebrobasilar Artery Occlusion in the Acute Phase of Ischemic Stroke

OBJECTIVE

Although short-term clinical outcomes after basilar artery stent placement have been reported previously, effectiveness of intracranial stenting for vertebrobasilar artery occlusion in the acute phase of ischemic stroke is unclear.

METHODS

We clinically investigated 8 patients with intracranial percutaneous transluminal angioplasty (PTA) or stenting as our protocol for symptomatic atherosclerotic vertebrobasilar artery occlusion (age range, 54-80 years; mean age, 69 ± 11 years; 6 men and 2 women) who were admitted to our hospital between August 2013 and December 2015.

RESULTS

Two patients underwent PTA of the vertebrobasilar artery 2-5 months before stent placement. The other 6 patients underwent intracranial stenting just after PTA. Within the first 30 days after vertebrobasilar artery stent placement, 2 ischemic stroke complications affected patients. Ischemic complications were significantly associated with prestent lesion lumen greater than 0.5 mm. The modified Rankin Scale score and clinical outcome were significantly associated with complications. Clinical outcomes correlate with ischemic complications and vertebrobasilar anatomy.

CONCLUSIONS

Stent angioplasty may be a reasonably good treatment option for patients with technically favorable lesions, especially in vertebrobasilar atherosclerotic occlusion with medically or PTA only refractory symptoms. Despite a significant complication rate, most of our patients experienced good to excellent clinical outcomes and were free of vertebrobasilar ischemia at late midterm follow-up.

Intracranial Stenting for Cerebrovascular Pathology

After reading this article, the participant should be able to:

Describe the use of stent-assisted angioplasty for intracranial atherosclerotic disease. Recall the present status of stent-assisted managment of intracranial aneurysms. Describe the role of stenting and its technical aspects in the treatment of arteriovenous fistulae and acute stroke.

Long-term clinical and angiographic outcomes in patients with cervico-cranial dissections treated with stent placement: a meta-analysis of case series

Limited clinical and angiographic data exists for patients with spontaneous or traumatic cervico-cranial dissections treated with stent placement. We reviewed clinical and angiographic data on consecutive patients admitted to our hospital with spontaneous, traumatic, and iatrogenic cervico-cranial dissections treated with stent placement to study immediate and long-term clinical and angiographic outcomes. Additional patients were identified using pertinent studies published between 1980 and 2009, using a search of the PubMed, Cochrane, and Ovid libraries. Post-procedure complications and clinical outcomes were documented. Angiographic abnormalities collected at follow-up included presence of in-stent restenosis or pseudoaneurysm. After applying our strict search criteria, four studies including our series were used in the meta-analysis, representing 46 patients (mean age [standard deviation] 47 ± 14 years; 24 [52%] male) treated with stent placement for dissection. Overall, 72 stents were placed to treat 28 spontaneous, 11 traumatic, and 7 iatrogenic dissection patients with 51 dissections, involving 51 vessels; with a mean pre-stent stenosis of 71 ± 26% and mean post-stent stenosis of 6 ± 15%. The immediate and follow-up post-procedure complication rates per stent placed was 8 (11%) and 8 (11%), respectively. Among the 36 patients who underwent follow-up angiography, in-stent restenosis or pseudoaneurysms were present in 3 (8%) and 2 (6%) patients, respectively. A high rate of sustained resolution of angiographic abnormalities during long-term follow-up was noted, with a low rate of new transient ischemic attack, ischemic stroke, or death, supporting the feasibility, safety, and effectiveness of endovascular stent reconstruction.

Y-stent-assisted coil embolization for the management of unruptured cerebral aneurysms: report of six cases

BACKGROUND

The advent of stent-assisted coil embolization has revolutionized the endovascular management of complex intracranial aneurysms. Although performed routinely in most cerebrovascular centers, there are not many case series reported about the Y-stent technique for coil placement in cerebral aneurysms. The authors present the second largest series available within the neurosurgical literature.

METHODS

The authors have retrospectively reviewed the medical records and angiographic data of six patients who were diagnosed as having unruptured cerebral aneurysms and subsequently treated using "Y" stent-assisted coil embolization. Five out of six cerebral aneurysms in this study were located at the basilar tip while the remaining one was at the left MCA trifurcation. Aneurysms ranged in size from 8-22 mm. All patients were female with ages ranging from 37-70 years. One patient presented with recurrence of an aneurysm previously managed with a balloon-assisted coil embolization. Another patient presented after a failed trial of a balloon-assisted procedure. One patient had originally been diagnosed with multiple aneurysms of varying size and location.

RESULTS

A "Y" configuration was successfully established in all six patients. Five patients have had a symptom-free recovery period at average follow-up period of 36.7 months. The remaining patient is notable for recurrence that was discovered on angiogram 32 months postoperatively.

CONCLUSIONS

The proposed Y-stent technique is a safe and effective option that can be employed in the endovascular reconstruction of unruptured intracranial aneurysms of complex location and orientation. These methods serve as an acceptable alternative in the management of aneurysms traditionally managed with microsurgery. Hemodynamic assessment has shown Y-stenting to be an advantageous therapy option, yet further studies are required to assess these parameters in alternative therapies.

Intravascular ultrasonography-guided stent angioplasty of an extracranial vertebral artery dissection

The authors report on a case of intravascular ultrasonography (IVUS)-guided stent angioplasty for iatrogenic extracranial vertebral artery (VA) dissection in a 49-year-old man after coil embolization for an unruptured aneurysm of the right posterior inferior cerebellar artery. Insignificant dissections occurred during the procedure. Postoperatively, the patient experienced gradually worsening posterior neck pain and headache, and follow-up angiography 8 months after the coil embolization revealed expansion of the dissection. The patient underwent stent angioplasty with IVUS guidance and his symptoms improved.

To the authors' knowledge, this is the first report of IVUS-guided stent angioplasty of an extracranial VA dissection. It was safe and feasible to treat extracranial VA dissections with stent placement under IVUS guidance. Intravascular environments are in real time with IVUS, and this technique is useful in the confirmation of a true lumen and evaluation of appropriate stent apposition. More clinical experience with this technique is necessary and mandatory, and devices with smaller diameters with improved trackability are essential for further introduction of IVUS into the field of endovascular neurosurgery.

Symptomatic spontaneous intracranial carotid artery dissection treated with a self-expanding intracranial nitinol stent: a case report

BACKGROUND

Although extracranial carotid dissection with stroke is common, intracranial dissection with stroke is rare. Stenting has been used to treat extracranial carotid dissections. Intracranially, however, it is only recently that stents have become a feasible option for this disease. We present a case of a spontaneous intracranial CAD with progressive symptoms despite medical management treated with a self-expanding intracranial micronitinol stent.

CASE DESCRIPTION

A 47-year-old, right-handed woman presented to the emergency department after noticing left-sided face and arm weakness and numbness, along with slurred speech. The patient was started on aspirin 325 mg/d orally and lovenox 40 mg/d subcutaneously. On hospital day 2, the patient was noted to have repeated episodes of weakness and numbness on the left side and MRI evidence of a new stroke. A diagnostic cerebral angiogram from a selective right internal carotid injection revealed a flow-limiting stenosis secondary to a dissection of the supraclinoid internal carotid artery with severe flow limitation to the hemisphere. Endovascular management was decided on, and a Neuroform stent measuring 4.5 x 20 mm (Boston Scientific Corporation, Natick, Mass) was deployed across the dissection with significant improvement of flow to that hemisphere on the poststent angiogram.

CONCLUSIONS

This case illustrates the successful off-label use of a self-expanding intracranial nitinol stent to treat a symptomatic intracranial internal CAD in the setting of failure of traditional medical management. This is a promising application of novel endovascular technology.

ENDOVASCULAR TREATMENT OF DISTAL CERVICAL AND INTRACRANIAL DISSECTIONS WITH THE NEUROFORM STENT

OBJECTIVE

Endovascular stent reconstruction is the primary intervention for cervical and intracranial dissections in symptomatic patients refractory to medical management. Advancement of traditional balloon-expanding stents into the distal internal carotid artery and vertebrobasilar artery can be technically challenging and potentially traumatic.

METHODS

On retrospective review, nine patients at our institution with distal cervical and/or intracranial dissections were alternatively treated with the self-expanding, dedicated intracranial Neuroform stent. Three patients with dissecting aneurysms also required stent-assisted coil embolization. Seven patients were followed with imaging and clinical assessment for a mean of 16.3 months.

RESULTS

All patients (five men, four women; mean age, 50 yr) were symptomatic. Spontaneous (n = 4) or traumatic and/or iatrogenic (n = 5) dissections involved the internal carotid artery (n = 2), vertebral artery (n = 5), and vertebrobasilar artery (n = 2). Indications for treatment included transient ischemic attacks, impending infarcts, antiplatelet failure, enlarging or ruptured dissecting aneurysms, intracranial dissections, or subarachnoid hemorrhages. Dissections were treated with single (n = 4), overlapping (n = 2), or tandem (n = 3) Neuroform stents. Dissection-related mean stenosis improved from 76% preprocedure to 23% postprocedure, with further reduction to 8% at follow-up imaging. Stent-assisted coil embolization of large dissecting aneurysms (n = 3) resulted in retreatment of a neck remnant (n = 1). Small dissecting aneurysms (n = 5) underwent spontaneous stent-induced thrombosis. There were no procedure-related complications. Mortality was limited to the presenting sequelae of vertebrobasilar artery thrombosis (n = 2). Suboptimal technical outcomes were related to delayed in-stent stenosis (n = 2). All surviving patients (n = 7) reported clinical improvement or resolution of symptoms.

CONCLUSION

The Neuroform stent seems to be safe and technically effective in the endovascular management of distal cervical and intracranial dissections, with favorable clinical outcomes.

Endovascular treatment of a basilar artery dissecting aneurysm

Basilar artery (BA) dissecting aneurysms pose difficulties to treatment because both bleeding and thrombosis can happen in the same patient, clinical course is unpredictable and high morbidity is usual. We report the case of a 37-year-old woman with a BA aneurysm probably caused by arterial dissection, presenting embolic and hemorrhagic complications. The aneurysm was submitted to endovascular treatment with stenting and coil embolization. Clinical and radiological results were excellent and no complications were observed, suggesting that BA stenting and coil embolization may be a safe and effective treatment for this condition.

Stenting for vertebrobasilar dissection: a possible treatment option for nonhemorrhagic vertebrobasilar dissection

INTRODUCTION

It has been reported that stent placement may improve compromised blood flow resulting from vertebrobasilar dissection. In this study the technical feasibility, safety, as well as short-term outcome of stent placement for the treatment of nonhemorrhagic vertebrobasilar dissection was retrospectively investigated.

METHODS

Ten patients (eight men, two women; age range 36 to 45 years) with nonhemorrhagic vertebrobasilar dissection were treated by stenting. Nine lesions were located at the vertebral artery (VA) (one bilateral case) and two at the basilar artery. Seven patients presented with ischemic symptoms and three with headache. Among the nine VA dissections, eight lesions involved the posterior inferior cerebellar artery (PICA). Angiographic findings included abrupt or irregular vessel narrowing with aneurysmal dilatation in nine lesions and irregular bulbous aneurysmal dilatation in two lesions.

RESULTS

Placement of a stent-within-a-stent was performed in six lesions and single stent in five lesions. Initial treatments were technically successful in all patients. Follow-up was performed using digital subtraction angiography (six patients) or CT angiography (two patients). Successful occlusion or decreased contrast filling of the aneurysm sac was noted in six patients (seven lesions), increased aneurysm sac filling in one patient, and parent artery occlusion in one patient. PICA flow was preserved in all those with follow-up (1 week to 17 months).

CONCLUSION

Stent placement is technically feasible and safe for the treatment of vertebrobasilar artery dissection, especially for preserving PICA and/or major perforating arteries. However, a study with a larger population and longer follow-up is necessary for validation of the efficacy of this treatment modality.

Management of symptomatic intracranial arterial stenosis: endovascular therapy

Patients with symptomatic intracranial stenosis are at high risk of subsequent stroke despite the use of antithrombotic agents or surgical management. Although endovascular therapy appears to promise therapeutic solutions, the reported high peri-procedural adverse event rate limits the widespread use of this technique. In the past few years, the morbidity and mortality associated with intracranial angioplasty and stenting have decreased with the development of new intracranial specific devices. The most recent prospective studies on intracranial stenting have been nothing more than registries of patients with symptomatic intracranial stenosis of 50% or greater who have failed medical therapy. However, no randomized controlled data exist on the comparison between endovascular therapy and medical treatment. There are new data identifying factors associated with a higher risk of stroke in medically treated patients. These findings will help to define a high-risk patient population on whom the initial controlled trials will be conducted.

Intracranial angioplasty and stenting for cerebrovascular disease

The use of stent-assisted techniques to manage a variety of cerebrovascular conditions has exploded in recent years. Although the safety of devices is expected to continue to improve, the absence of scientific validation remains an issue in many indications. In posterior circulation arterial disease, considering the absence of valid and reasonable surgical options and the results of the WASID trial, there is widespread consensus that endovascular therapy will become the main option. In anterior circulation intracranial disease, surgical revascularization (EC/IC bypass) may continue to remain an option in selected patients, although it is unclear whether or not randomized clinical trials would be either useful or feasible. The treatment of wide-necked intracranial aneurysms has benefited greatly from the advent of stenting. Intracranial arterial dissections are uncommon and life threatening enough for stenting to remain a major, if not the only, treatment option in many; flexible covered microstents may become the preferred treatment in arterial segments that do not harbor perforators. Concerning the endovascular management of pseudotumor cerebri, as more insight is gained into the epidemiology and the pathophysiology of the disease, it is likely that validation against conventional surgical shunt techniques will be required, at least in subgroups of patients. There is no doubt at this point that large numbers of patients will continue to benefit from the technique. A strong focus on patients' specific needs, a thorough multidisciplinary approach, and continuing efforts in research are necessary to help maintain procedural risks as low as possible.

Stent-angioplasty of intracranial vertebral and basilar artery stenoses in symptomatic patients

BACKGROUND

To present our two-center treatment results with stent angioplasty of intracranial vertebrobasilar stenoses in symptomatic patients.

MATERIAL AND METHODS

Between 2001 and 2003, 21 patients with 22 stenoses, refractory to medical therapy, who underwent elective stenting of intracranial vertebrobasilar stenoses were retrospectively analyzed. All patients had ischemic events clinically referable to the stenoses. Only high-grade stenoses of at least 80% were treated. Clinical evaluation was done based on the modified ranking scale (MRS).

RESULTS

In all cases, the stent deployment turned out to be technically successful and control angiography demonstrated the elimination of the high-grade stenoses. A minor residual stenoses was still detectable in six cases. According to the MRS, clinical outcome improved in the case of four patients, seemed unchanged in 14 and worsened in three. The clinical morbidity rate amounted to 14%. Clinical follow-up was available for 13 patients after 9 months with no recurrent symptoms and angiographic follow-up was available after 10 months. Re-stenoses occurred in two cases without clinical symptoms. Retreatment was not done.

CONCLUSION

According to our data, stent angioplasty for symptomatic intracranial vertebrobasilar stenoses can be a treatment alternative in case of recurrent symptoms despite medical therapy; particularly, for stenoses of type Mori A or B.

Primary Stenting of Intracranial Atherosclerotic Stenoses

PURPOSE

To determine the feasibility and safety of stenting intracranial atherosclerotic stenoses.

METHODS

In 12 patients the results of primary intracranial stenting were evaluated retrospectively. Patient ages ranged from 49 to 79 years (mean 64 years). Six patients presented with stenoses in the anterior circulation, and six had stenosis in the posterior circulation. One patient presented with extra- and intracranial tandem stenosis of the left internal carotid artery. Three patients presented with acute basilar thrombosis, caused by high-grade basilar stenoses.

RESULTS

Intracranial stenoses were successfully stented in 11 of 12 patients. In one patient the stent could not be advanced over the carotid siphon to reach the stenosis of the ophthalmic internal carotid artery. Follow-up digital subtraction angiographic studies were obtained in two patients who had presented with new neurologic signs or symptoms. In both cases the angiogram did not show any relevant stenotic endothelial hyperplasia. In one patient, after local thrombolysis the stenosis turned out to be so narrow that balloon angioplasty had to be performed before stent deployment. All three patients treated for stenosis-related basilar thrombosis died due to brainstem infarction that had ensued before the intervention.

CONCLUSIONS

Prophylactic primary stenting of intracranial stenoses of the anterior or posterior cerebral circulation can be performed with a low complication rate; technical problems such as stent flexibility must still be solved. Local thrombolysis followed by stenting in stenosis-related thrombotic occlusion is technically possible.

Buenos Aires experience with the Neuroform self-expanding stent for the treatment of intracranial aneurysms

OBJECT

The authors report their experience with the use of the Neuroform Microdelivery System for intravascular reconstruction. They assess the technical feasibility of the system, the efficacy of the combined application of stent and detachable coils, and the follow-up findings.

METHODS

Fifty patients found to harbor a complex wide-necked intracranial aneurysm were selected for the study. Different strategies were chosen and the performance and technical success of the device were evaluated. Stent placement was recorded as optimal or suboptimal with respect to the stent position. Clinical and angiographic follow-up examinations were obtained. Forty-six patients with 48 intracranial aneurysms were treated, leading to a technical success rate of 92%. Forty-two lesions were located in the anterior circulation. In every case the dome/neck ratio was less than 2 and the mean aneurysm size in these patients was 8.8 mm. The most frequent clinical presentation was subarachnoid hemorrhage in 48% of cases. Stent placement was optimal in 81.2% of cases and suboptimal in 18.8%. In 31% of cases, the investigators encountered difficulties in placing the Neuroform stent. Clinical follow up was recorded in all patients and angiographic follow up was obtained in 63%. There were no cases of repeated hemorrhage. In a single case in which only the stent was implanted progressive thrombosis was identified during the follow-up period. The procedure-related morbidity and mortality rates were 8.6 and 2.1%, respectively.

CONCLUSIONS

On the basis of the results, the authors conclude that the Neuroform self-expanding stent is a flexible and useful device that can be readily and safely maneuvered through tortuous intracranial vessels, enabling the endovascular treatment of complex wide-necked aneurysms. Early in the authors' experience, stent delivery presented difficulties; however, a second generation of devices has resolved this limitation. Although the early results are promising, the long-term benefit of this technique has to be proved by angiographic and clinical follow-up examinations.

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.

Spontaneous Intracranial Internal Carotid Artery Dissection Treated by Intra-arterial Thrombolysis and Superficial Temporal Artery-Middle Cerebral Artery Anastomosis in the Acute Stage-Case Report-

A 22-year-old man presented with sudden onset of right retro-orbital headache followed by left hemiparesis. Right carotid angiography demonstrated almost total occlusion of the intracranial internal carotid artery (ICA) and severe stenosis of the middle cerebral artery (MCA), presumably caused by arterial dissection. Local arterial injection of urokinase was performed 2 hours after onset. The ICA became patent, but the M2 portion of the MCA was still occluded, and the left hemiparesis did not improve. Superficial temporal artery-MCA anastomosis was immediately performed. The left hemiparesis disappeared completely 6 days after this procedure. Angiography 2 weeks after the onset revealed occlusion of the ICA, and maintenance of blood flow to the right cerebral hemisphere via the anastomosis. Magnetic resonance imaging showed small infarcts in the right cerebral cortex. Repeat angiography after 5 months showed recanalization of the right ICA and the right MCA. Combination of thrombolytic therapy and bypass surgery may be a useful treatment option for patients with sudden occlusion of the intracranial artery caused by dissection.

Endovascular treatment of basilar artery dissection by stent deployment. A case report

SUMMARY

We describe a 44 year-old woman with dissection of the distal third of the basilar artery presenting with subarachnoid haemorrhage. She was treated with a Neuroform stent (Boston Scientific), the first stent designed for intracranial navigation and recently approved by the FDA to treat wide-necked cerebral aneurysms and allow reconstruction of the internal lumen. In our patient, the dissection involved the origin of the anterosuperior cerebellar artery and the origin of the right posterior cerebral artery. The stent was positioned without complications during or after the procedure. Intra and periprocedural thrombolytic therapy was given followed by an antiaggregant (100 mg Aspirin) for a year after treatment. Subsequent angio-MR and angiographic monitoring disclosed resolution of the dissection and normalization of the basilar artery lumen. She currently lives a controlled but normal life.

Treatment and Short-Term Follow-up of Symptomatic Atherosclerotic Intracranial Artery Stenosis by Stent-Assisted Angioplasty

SUMMARY

Atherosclerotic intracranial artery stenosis can cause hypoperfusion of brain tissues and embolus formation, causing stroke. Conservative medical treatment seemed to have little effect on the natural history and prevent the stroke attack caused by artery stenosis. The purpose of stent-assisted angioplasty is to reconstruct the damaged vessels: the indications, feasibility, effectiveness, complications and follow-up for this new treatment method are discussed. A series of 32 cases with symptomatic intracranial artery stenosis were accepted from 1998 to 2002. The mean age was 42 yrs (31 ~ 76 yr), male/female ratio=23/9. All patients were refractory to optimal medical therapy. Lesions included 12 middle cerebral arteries (37.5%), six basilar arteries (18.75%), three distal ICAs (9.38%) and 12 intracranial Vas (37.5%). All patients were treated by methods of transluminal stent-assisted angioplasty under general anesthesia. Patients were premedicated with Aspirin (300mg/per day) and Ticlopidine (250mg/per day), this was continued for six weeks after the procedure. Medical history, anamnesis, and treatment protocol were reviewed and evaluated retrospectively, shortterm follow-up (2mths ~ 1 yr) was also obtained. Primary clinical presentations were TIAs (21/32, 65.63%), minor stroke ( 8/32, 25%) and severe stroke (3/32, 9.38%). 31 cases (96.86%) were successfully implanted with coronary stents within the stenosed vessels; technical success rate was 96.86%. Instant angiographic results showed the stenosed extent had decreased from 72.36% +/- 5.69 to 10.16% +/- 6.94. One vessel ruptured during the procedure, the patient recovered after surgical repair of the ruptured vessel. Clinical follow-up demonstrated symptoms resolved in most patients (30/32, 93.75%) within the follow- up period, two cases with MCA stenosis had TIAs within two months after the procedure. 12 cases accepted angiographic follow-up.Velocities of stented vessels of five cases (5/21, 23.81%) increased compared to instant results, suggesting restenosis, three of them were confirmed by angiography which included two cases with MCA stenosis (figure 3) and one with distal VA, one of the five cases had recurred TIAs. With the newer generation of coronary stent, this technique seemed safe, feasible and effective to prevent stroke attack, but the indication is very important for the technical success. Restenosis remains a common problem as with coronary stenting. Long-term follow-up will be needed.

Endovascular coil occlusion of intracranial aneurysms assisted by a novel self-expandable nitinol microstent (neuroform)

SUMMARY

Endovascular treatment of wide neck intracranial aneurysms is technically difficult and leads to less favorable treatment results and long term outcome. We participated in a multicenter prospective study to evaluate the safety and performance of a new self-expandable nitinol micro stent (Neuroform) in stent assisted coil occlusion of wide neck intracranial aneurysms. Eighteen patients were enrolled in the study in a single center. The anatomy of the target aneurysm and the parent vessel, technical details of the procedure, device functionality, anatomic and clinical results were evaluated. All enrolled aneurysms were either wide necked or showed an unfavorable neck-to-fundus ratio. In 16 out of 18 patients the Neuroform device allowed stent assisted coil occlusion of the aneurysm. The occlusion rate was 95% in eight patients and 100% in eight patients. The two failures were both due to anatomic reasons. Flexibility of the stent, behavior during deployment and subsequent ability to retain coils within the aneurysmal sac were considered as good as or better than the properties of previous balloon expandable stents. No device-related adverse events were encountered. Procedure-related clinical complications occurred in seven patients but caused no severe permanent neurological deficit. The Neuroform neurovascular stenting system is a safe and effective adjunct for the stent-assisted coil occlusion of wide necked intracranial aneurysms. The major advantages of this device are its self-expanding property and very high flexibility which allows safe navigation, easy sizing, as well as accurate positioning of the stent while providing sufficient bridging of the aneurysm neck for subsequent coil placement.

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.

Transcranial color-coded sonography in basilar artery stenting

Basilar artery (BA) stenting is an emerging technique with promising results in revascularization of severe arteriosclerotic stenoses. Because of the limitations associated with other noninvasive techniques, we applied transcranial color-coded sonography (TCCS) in the follow-up. Successful stent application in two cases of acute basilar occlusion caused by thrombosis on pre-existing severe midbasilar stenoses was initially confirmed by angiography. Later recanalization was controlled noninvasively by magnetic resonance angiography (MRA), computed tomographic angiography (CTA) and TCCS. Ultrasound (US) was performed through the transtemporal bone window; a contrast-enhancing agent had to be used in one case. TCCS showed an orthograde flow in the distal BA in both patients without signs of severe stenoses. Transtemporal TCCS was demonstrated to be a noninvasive bedside technique in monitoring the patency of the BA after stenting.

Improved cerebral perfusion and metabolism after stenting for basilar artery stenosis: technical case report

OBJECTIVE

Recent advances in stent technology have allowed the introduction of more flexible stents that may be tracked more easily in the intracranial vessels. We present a patient with improved cerebral blood flow and metabolism as assessed by positron emission tomography after stent-assisted angioplasty for symptomatic basilar artery stenosis.

CLINICAL PRESENTATION

A 62-year-old man, who had undergone left superficial temporal artery to middle cerebral artery bypass surgery for left internal carotid artery occlusion 10 years previously, presented with dizziness, blurred vision, and memory disturbance. Angiography revealed severe stenosis of the proximal basilar artery. Positron emission tomographic scans revealed decreased cerebral blood flow associated with increased oxygen extraction fraction in the entire brain, particularly in the posterior circulation and the left middle cerebral artery territory. Despite medical treatment, the patient experienced worsening visual disturbance and right-sided motor weakness.

INTERVENTION

Ticlopidine and aspirin were used as antiplatelet agents. In addition, we used argatroban, which is a direct thrombin inhibitor, as an anticoagulant during the procedure. Predilation with a coronary artery balloon was performed, followed by placement of a GFX 3- by 8-mm stent (Arterial Vascular Engineering, Santa Rosa, CA), with excellent angiographic results. The patient made a good neurological recovery, and the postoperative positron emission tomographic scan demonstrated increases in both cerebral blood flow and cerebral metabolic rate of oxygen with a normalization of oxygen extraction fraction.

CONCLUSION

Stent-assisted angioplasty can provide a favorable clinical course as well as improved cerebral perfusion and metabolism for a patient with basilar artery stenosis. Long-term follow-up data and additional clinical experience are required to assess the durability of this approach.

Transluminal stent-assisted angiplasty of the intracranial vertebrobasilar system for medically refractory, posterior circulation ischemia: early results

OBJECTIVE

Symptomatic vertebrobasilar artery stenosis portends a poor prognosis, even with medical therapy. Surgical intervention is associated with considerable morbidity, and percutaneous angioplasty alone has demonstrated mixed results, with significant complications. Recent advances in stent technology have allowed for a novel treatment of symptomatic, medically refractory, vertebrobasilar artery stenosis. We report on a series of patients with medically refractory, posterior circulation stenosis who were treated with transluminal angioplasty and stenting at two medical centers in the United States.

METHODS

A retrospective analysis of data for 11 consecutive patients with symptomatic, medically refractory, intracranial, vertebral or basilar artery stenosis was performed. All patients were treated with percutaneous transluminal angioplasty and stenting. Short-term clinical and angiographic follow-up data were obtained.

RESULTS

Among 11 patients who were treated with stent-assisted angioplasty of the basilar or vertebral arteries, there were three periprocedural deaths and one delayed death after a pontine stroke. Other complications included a second pontine infarction, with subsequent residual diplopia. The remaining seven patients (64%) experienced symptom resolution and have resumed their preprocedural activities of daily living. Angiographic follow-up examinations demonstrated good patency of the stented lesions for five of seven survivors (71%); one patient exhibited minimal intrastent intimal hyperplasia, and another patient developed new stenosis proximal to the stent and also developed an aneurysm within the stented portion of the basilar artery. The last patient exhibited 40% narrowing of the treated portion of the vessel lumen.

CONCLUSION

Recent advances in stent technology allow negotiation of the proximal posterior circulation vasculature. Although the treatment of vertebrobasilar artery stenosis with angioplasty and stenting is promising, long-term angiographic and clinical follow-up monitoring of a larger patient population is needed.

Provisional stenting for symptomatic intracranial stenosis using a multidisciplinary approach: acute results, unexpected benefit, and one-year outcome

Percutaneous techniques have dramatically changed our approach to coronary and peripheral revascularization. Intracranial atherosclerosis is a highly morbid disease; however, techniques for revascularization are still in evolution. The authors comprise a multidisciplinary team of neurologists, neuroradiologists, and interventional cardiologists who have collaborated in treating fifteen patients with symptomatic intracranial stenosis who have failed medical therapy. The acute success rate (100%) and one-year freedom from death and stroke (93.4%) using balloon angioplasty and provisional stenting are encouraging. A surprising observation in this patient cohort was that 53% of patients had improvement or resolution of a deficit that was chronic and presumed to be permanent and irreversible. This type of chronic but reversible deficit is termed "brain angina". The background, rationale for a multidisciplinary team, techniques, and preliminary results of intracranial angioplasty with provisional stenting are presented.

Cerebrovascular angioplasty and stenting for the prevention of stroke

Until recently, stroke preventive strategies have focused on either medical regimens aimed at antagonizing or reversing atherosclerosis, or surgical intervention for revascularization of the cerebrovascular system. However, with the advent of rapidly emerging microcatheterization techniques and technology, endovascular surgical revascularization of the brain is rapidly emerging as a powerful therapeutic modality. In particular, significant advances already have been made in revascularization of the extracranial carotid artery and many common anatomic sites of intracranial athero-occlusive disease, using special adaptations of conventional percutaneous angioplasty and stenting techniques. This paper reviews the cumulative experience with these emerging techniques, with a particular emphasis on clinical outcomes and future directions. It also reports the substantial cumulative institutional experience of the authors over the past 18 months with both extracranial carotid and intracranial artery stent-assisted carotid angioplasty.

Cerebral hyperperfusion syndrome after percutaneous transluminal stenting of the craniocervical arteries

OBJECTIVE

Cerebral hyperperfusion syndrome is a recognized complication of carotid endarterectomy, with a reported incidence of 0.3 to 1.2%. The incidence of cerebral hyperperfusion after endovascular revascularization procedures of the craniocervical arteries remains unknown. We evaluated the incidence of cerebral hyperperfusion syndrome in our endovascular revascularization series. To our knowledge, there are no previous studies evaluating the incidence of hyperperfusion syndrome after percutaneous transluminal angioplasty/stenting.

METHODS

Between March 1996 and February 2000, 140 patients underwent percutaneous transluminal angioplasty/stenting of the craniocervical arteries at our institution. In all patients, selective bilateral arteriography of the carotid and vertebral arteries was performed to document the sites of craniocervical stenosis and collateral blood flow and the results of the endovascular revascularization procedure. We then reviewed all pertinent medical records, arteriographic films, and sectional imaging studies to determine the incidence of cerebral hyperperfusion in this series.

RESULTS

Seven patients (5.0%) developed clinical or radiological manifestations of cerebral hyperperfusion. In the target group, percutaneous transluminal stenting achieved a 90 to 100% reduction in stenotic lesions (mean stenosis, 91%) of the carotid (n = 5) and vertebral (n = 2) arteries. All seven patients remained neurologically stable immediately after treatment. There was delayed development of clinical and radiographic findings, suggestive of cerebral hyperperfusion. Six patients showed evidence of ipsilateral hemispheric edema, including two patients who developed intracranial hemorrhage (one parenchymal, one parenchymal and subarachnoid) documented by computed tomographic brain scans. Symptoms resolved within 72 hours in the four patients without hemorrhage. The two patients with hemorrhage recovered during a more protracted period (range, 3 wk to 6 mo). There were no long-term sequelae or deaths during a cumulative follow-up of 84 months (mean follow-up, 12 mo).

CONCLUSION

Hyperperfusion syndrome is an uncommon but potentially serious complication of extracranial and intracranial angioplasty and stenting procedures. The clinical manifestations are similar to hyperperfusion syndrome after carotid endarterectomy; however, the prevalence may be greater in the high-risk cohort commonly referred for endovascular treatment. Our findings suggest that patients undergoing endovascular stenting procedures should be closely monitored for evidence of hyperperfusion, with careful monitoring of blood pressure, heart rate, and anticoagulation. Further research is needed to confirm that cerebral hyperperfusion is the pathogenesis of this condition.

Carotid angioplasty and stenting: new horizons

Advances in technology have made it possible for lesions that affect the carotid artery, both extra-and intracranially, to be treated by endovascular means. Depending upon the type and location of the pathology, as well as the existing comorbidities in any given patient, angioplasty and stenting may be considered an alternative to traditional methods of revascularization. In fact, in some instances, endovascular therapy may be the procedure of choice. For patients whose lesions can be treated either surgically or endovascularly, future randomized trials will help define the role of each type of procedure.