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Object: Animal aneurysm models are required for the study of the hemodynamics and pathophysiology of intracranial aneurysms in humans and so that experimental treatments can be tested prior to clinical trials. The authors developed a canine model that consistently produces up to three bifurcation aneurysms similar in morphological features and hemodynamics to human intracranial aneurysms., Methods: In 10 mongrel dogs, a harvested segment of the external jugular vein was anastamosed to an external carotid artery (CA)-lingual artery bifurcation arteriotomy site to create a lateral bifurcation aneurysm. The surgery was repeated on the contralateral side in each animal to form a second lateral bifurcation aneurysm and, in five dogs, a CA-CA crossover anastomosis was also performed to create a terminal bifurcation aneurysm. Nineteen of 20 lateral bifurcation aneurysms were confirmed in 10 dogs by diagnostic angiography 7 to 14 days after surgery. Aneurysm fundus-to-neck ratios ranged from 1 to 2, depending on the size of the arteriotomy. The terminal bifurcation aneurysms were confirmed in all five dogs by diagnostic angiography 7 to 14 days after the procedure. The authors later tested endovascular techniques for embolizing the aneurysms., Conclusions: Three bifurcation aneurysms of sufficient size for endovascular access can be created in a reproducible fashion in the same animal. This model is useful for studying complex endovascular procedures in aneurysms that mimic the human condition and for testing new devices and techniques.

Object: To determine the rate of hemodynamically significant recurrent carotid artery (CA) stenosis after stent-assisted angioplasty for CA occlusive disease, the authors analyzed Doppler ultrasonography data that had been prospectively collected between October 1998 and September 2002 for CA stent trials., Methods: Patients included in the study participated in at least 6 months of follow-up review with serial Doppler studies or were found to have elevated in-stent velocities (> 300 cm/second) on postprocedure Doppler ultrasonograms. Hemodynamically significant (> or = 80%) recurrent stenosis was identified using the following Doppler criteria: peak in-stent systolic velocity at least 330 cm/second, peak in-stent diastolic velocity at least 130 cm/second, and peak internal carotid artery/common carotid artery velocity ratio at least 3.8. Follow-up studies were obtained at approximate fixed intervals of 1 day, 1 month, 6 months, and yearly. Angiography was performed in the event of recurrent symptoms, evidence of hemodynamically significant stenosis on Doppler ultrasonography, or both. Treatment was repeated because of symptoms, angiographic evidence of severe (> or = 80%) recurrent stenosis, or both of these. Stents were implanted in 142 vessels in 138 patients (all but five patients were considered high-risk surgical candidates and 25 patients were lost to follow-up review). For the remaining 112 patients (117 vessels), the mean duration of Doppler ultrasonography follow up was 16.42+/-10.58 months (range 4-54 months). Using one or more Doppler criteria, severe (> or = 80%) in-stent stenosis was detected in six patients (5%). Eight patients underwent repeated angiography. Six patients (three with symptoms) required repeated intervention (in four patients angioplasty alone; in one patient conventional angioplasty plus Cutting Balloon angioplasty; and in one patient stent-assisted angioplasty)., Conclusions: In a subset of primarily high-risk surgical candidates treated with stent-assisted angioplasty, the rates of hemodynamically significant restenosis were comparable to surgical restenosis rates cited in previously published works. Treatment for recurrent stenosis incurred no instance of periprocedure neurological morbidity.

Object: Few researchers have quantified the role of arterial geometry in the pathogenesis of saccular cerebral aneurysms. The authors investigated the effects of parent artery geometry on aneurysm hemodynamics and assessed the implications relative to aneurysm growth and treatment effectiveness., Methods: The hemodynamics of three-dimensional saccular aneurysms arising from the lateral wall of arteries with varying arterial curves (starting with a straight vessel model) and neck sizes were studied using a computational fluid dynamics analysis. The effects of these geometric parameters on hemodynamic parameters, including flow velocity, aneurysm wall shear stress (WSS), and area of elevated WSS during the cardiac cycle (time-dependent impact zone), were quantified. Unlike simulations involving aneurysms located on straight arteries, blood flow inertia (centrifugal effects) rather than viscous diffusion was the predominant force driving blood into aneurysm sacs on curved arteries. As the degree of arterial curvature increased, flow impingement on the distal side of the neck intensified, leading to elevations in the WSS and enlargement of the impact zone at the distal side of the aneurysm neck., Conclusions: Based on these simulations the authors postulate that lateral saccular aneurysms located on more curved arteries are subjected to higher hemodynamic stresses. Saccular aneurysms with wider necks have larger impact zones. The large impact zone at the distal side of the aneurysm neck correlates well with other findings, implicating this zone as the most likely site of aneurysm growth or regrowth of treated lesions. To protect against high hemodynamic stresses, protection of the distal side of the aneurysm neck from flow impingement is critical.

Object: Use of the sirolimus-eluting stent has led to a reduction of in-stent stenosis following treatment of coronary atherosclerosis, whereas treatment of intracranial atherosclerosis with bare-metal stents results in excessive restenosis rates of approximately 40%. Neurotoxicity effects and vessel injury are unknown in the cerebral vasculature. To assess the safety profile and vascular effects of sirolimus-coated stents, the authors conducted a prospective comparative study in which drug-eluting and bare-metal stents were implanted in the canine basilar artery (BA)., Methods: Sixteen mongrel dogs were randomized (eight animals per group) to receive either bare-metal 1.5 x 8-mm (six-cell) stents or sirolimus-eluting stents of the same dimensions. Interventionists, histopathologists, and histopathology technicians who participated in the study were blinded to the stent characteristics. Stents were implanted in the canine BA. Serial peripheral blood samples were obtained during the 1st week after implantation to determine the time-dependent serum concentration of sirolimus. Follow-up angiographic studies were performed 30 days after stent implantation to assess the effects of stent placement on the BA and brainstem perforating vessels. Explantation of the stent and BA was performed immediately after angiography by using a pressurized formalin fixation procedure. Histological and computer-assisted morphometric analyses of specimens obtained in each animal were performed. Sirolimus could not be detected in peripheral blood samples obtained later than 24 hours posttreatment. On follow-up angiography, all perforating vessels observed on initial angiograms remained patent, and no evidence of parent vessel damage or pseudoaneurysm formation was observed. Explanted vessels and brainstem sections did not demonstrate evidence of histological neurotoxicity, such as gliosis or infarction. No significant differences were found in the time to endothelialization of bare-metal and sirolimus-coated stents. Smooth-muscle cell (SMC) proliferation, the putative agent for restenosis, was lower in animals receiving sirolimus-coated stents (p = 0.003). Additionally, intimal fibrin density was increased in the dogs treated with sirolimus-coated stents (p < 0.0001). Histological evidence of an inflammatory response demonstrated a trend toward a reduced response in the sirolimus group (mean 0.58) compared with the bare-metal group (mean 0.83, p = 0.33)., Conclusions: No neurotoxic effects were observed in the intracranial vessel walls or brainstem tissue in which sirolimus-coated stents were implanted. Compared with bare-metal stents, the sirolimus-coated devices did not impair endothelialization and, furthermore, tended to reduce the proliferation of SMCs. These findings indicate that sirolimus-coated devices may inhibit in-stent stenosis. Further studies with longer-term follow up are required to assess the restenosis rates of sirolimus-coated stents implanted in the intracranial vasculature.

Object: Medically refractory, symptomatic atherosclerotic disease of the basilar artery (BA) portends a poor prognosis. Studies have shown morbidity rates following placement of stents in these lesions to be quite variable, ranging from 0 to 30%. The authors review their experience with BA stent placement for severe atherosclerotic disease to determine whether an increase in neurological morbidity is associated with direct stent placement (that performed without predilation angioplasty) compared with conventional stent placement (that performed immediately after predilation angioplasty) or staged stent placement (angioplasty followed > or = 1 month later by stent placement with or without repeated angioplasty)., Methods: The authors retrospectively reviewed the medical records from a consecutive series of 10 patients who underwent stent placement for medically refractory, symptomatic atherosclerotic disease of the BA between February 1999 and November 2002. Patient records were analyzed for symptoms at presentation, percentage of angiographically visible stenosis, devices used, procedure-related morbidity, and clinical and radiographic outcomes. Patients with symptomatic intracranial vertebral artery stenosis but without concomitant severe (> 50%) BA stenosis were excluded from the study. Four patients were treated with direct stent placement, three with a staged procedure (these were included in a previous publication), and three with conventional stent placement. In the group treated with direct stent placement, a dense quadriparesis developed in two patients after the procedure. Computerized tomography or magnetic resonance imaging revealed infarction of the ventral pons in these patients. In the staged stent placement group, no permanent neurological complications occurred after the procedure and, in the conventional stent placement group, one of three patients experienced a neurological complication involving homonymous hemianopsia., Conclusions: Direct stent placement in the BA is associated with a relatively high complication rate, compared with a staged procedure. Complications may result from an embolic shower following disruption of atheromatous plaque debris attained using high-profile devices such as stents, as demonstrated by the postoperative imaging appearance of acute pontine infarctions. Additionally, displacement of debris by the stent into the ostia (snowplowing) of small brainstem perforating vessels may be responsible for the complications noted. Although direct stent placement in peripheral and coronary vessels has been shown to be safe, the authors suggest that direct stent placement in the BA should be avoided to minimize the risk of periprocedure morbidity.

The authors report a case of an iatrogenic carotid-cavernous fistula (CCF) associated with intracranial angioplasty. Angioplasty was performed using a 3 x 10-mm Open Sail coronary balloon in a patient with high-grade stenosis of the left cavernous internal carotid artery (ICA). After angioplasty, a perforation developed in the cavernous ICA, resulting in a CCF. A 3.5 x 9-mm S670 coronary stent was used to treat the fistula. To the authors' knowledge, this is the first reported case in which a CCF developed after angioplasty was performed using a coronary balloon. Long-term angiographic and clinical evaluation is needed to test the suitability and durability of intracranial angioplasty and stent placement in the treatment of symptomatic intracranial stenosis.

Object: No animal model currently exists for the examination of time-dependent histological changes occurring in intracranial vessels after endoluminal stent placement. The authors' goal was to develop a reproducible in vivo model of stent implantation in intracranial vessels in dogs that was capable of demonstrating stent-related vascular changes after the implantation of coated and uncoated devices., Methods: The authors implanted heparin-coated or uncoated stents in the basilar arteries (BAs) of 11 mongrel dogs. In a 12th animal, one coated stent was implanted in the BA and a second uncoated one was implanted in the distalanterior spinal artery. All the devices were oversized to induce intimal injury. Surviving animals were observed for 12 weeks, after which they underwent repeated angiography before planned death and removal of the brain. Histological studies and computer-assisted morphometric analyses were conducted on stent-treated and untreated sections of the BAs to assess the percentage of stenosis, neointimal proliferation, vessel injury, and inflammation. Perforating vessels partially covered by stent struts ("jailing") were studied for evidence of stenosis or occlusion. The pathologist, interventionists, histopathologist, histopathology technicians, and radiologist were blinded to the stent type. Seven stents (three uncoated and four coated) were removed from the six animals that were observed during the follow-up period. The mean neointimal proliferation was 0.42 mm2 in the group treated with uncoated stents and 0.18 mm2 in the group treated with heparin-coated devices (p = 0.04). Neointimal thickness was significantly increased in the group with uncoated stents (p = 0.04). The mean percentage of occlusion was less (12%) in the group with heparin-coated stents, compared with 22% in the group with uncoated devices (p = 0.07). When comparing results between the heparin-coated and uncoated devices implanted in the five animals that received a single stent only, greater differences (indicating a benefit from heparin-coated stents) were observed in neointimal area (p = 0.009), neointima/media ratio (p = 0.001), neointimal thickness (p = 0.002), and percentage of occlusion (p = 0.009). All brainstem perforating vessels covered by stent struts remained patent., Conclusions: This in vivo intracranial stent model was developed to assess proliferative and inflammatory responses to endoluminal stent implantation in the cerebrovasculature. The results indicate that a lower percentage of occlusion occurs 12 weeks after implantation of heparin-coated compared with uncoated stents.

Object: Medically refractory symptomatic vertebrobasilar atherosclerotic disease has a poor prognosis. Studies have shown that longer (> or = 10 mm), eccentric, high-grade (> 70%) stenoses portend increased procedure-related morbidity. The authors reviewed their experience to determine whether a staged procedure consisting of angioplasty followed by delayed (> or = 1 month later) repeated angioplasty and stent placement reduces the morbidity associated with endovascular treatment of symptomatic basilar and/or intracranial vertebral artery (VA) stenoses., Methods: The authors retrospectively reviewed the medical records in a consecutive series of eight patients who underwent planned stent-assisted angioplasty for medically refractory, symptomatic atherosclerotic disease of the intracranial posterior circulation between February 1999 and January 2002. Staged stent-assisted angioplasty was planned for these patients because the extent and degree of stenosis of the VA and/or basilar artery (BA) lesion portended an excessive procedure-related risk. The degree of stenosis, recent onset of symptoms (unstable plaque), vessel tortuosity, and lesion length and morphological feaures were contributing factors in determining procedure-related risk. Patient records were analyzed for location and degree of stenosis, preprocedural regimen of antiplatelet and/or anticoagulation agents, devices used, procedure-related complications, and clinical and radiographic outcomes. Among the patients in whom staged stent-assisted angioplasty was planned, vessel dissection, which necessitated immediate stent placement, occurred during passage of the balloon in one of them. In a second patient, the stent could not be maneuvered through the tortuous VA. In a third patient, the VA and BAs remained widely patent after angioplasty alone, and therefore stent placement was not required. Significant complications among the eight patients included transient aphasia and hemiparesis in one and a groin hematoma that necessitated surgical intervention in another; there was no permanent neurological morbidity. The mean stenosis before treatment was 78%, which fell to 54% after angioplasty, and the mean residual stenosis after stent placement was 30%. At the last follow-up examination, none of the treated patients had further symptoms attributable to the treated stenosis., Conclusions: The novel combination of initial angioplasty followed by delayed endoluminal stent placement may reduce the neurological morbidity associated with endovascular treatment of long, high-grade stenotic lesions. Attempting to cross high-grade stenoses with higher-profile devices such as stents may result in an embolic shower. Furthermore, neointimal proliferation and scar formation after angioplasty result in a thickened fibrous layer, which may be protective during delayed stent deployment. Larger-scale studies involving multiple centers are needed to elucidate further the lesion morphological characteristics and patient population most likely to benefit from staged procedures.

Object: The authors report their experience with carotid artery stent placement (CASP) in patients with concomitant carotid artery (CA) and coronary artery (CorA) diseases., Methods: In a review of 320 consecutive patients who underwent CASP, the authors identified 49 with severe CorA disease in addition to significant CA stenosis, who had undergone CASP before planned CorA bypass grafting (CorABG). The average age of these 49 patients was 68 years. In 39 patients (80%) the New York Heart Association functional classification grade was IV and in 10 the grade was III. In 26 patients 50% or greater stenosis of the left main CorA was found. Seventeen patients (35%) suffered from either significant hemodynamic contralateral CA stenosis (> 60% stenosis; eight patients) or contralateral CA occlusion (nine patients). Sixteen patients (33%) had symptomatic CA disease. No cerebrovascular events occurred during CorABG. Four patients (8%) died of cardiac arrest and one patient (2%) suffered a major stroke within 30 days after the CorABG procedure. No patient experienced clinically significant recurrent CA stenosis during the study period (average clinical follow-up period 27 months)., Conclusions: Carotid artery stent placement should be considered as an alternative for the management of concomitant CA and CorA diseases. These preliminary results support the feasibility and durability of CASP in the population studied.

Object: Embolization of intracranial aneurysms performed using Guglielmi detachable coils (GDCs) is performed with the patient in a state of general anesthesia at most centers. Such an approach does not allow intraprocedural evaluation of the patient's neurological status and carries additional risks associated with general anesthesia and mechanical ventilation. At the authors' institution, GDC embolization of intracranial aneurysms is performed in awake patients after administration of sedative and analgesic agents (midazolam, fentanyl, morphine, and/or hydromorphone). To determine the feasibility and safety of this approach, the authors have retrospectively reviewed their clinical experience., Methods: The authors reviewed the medical records of all patients in whom GDC embolization for the treatment of intracranial aneurysms was undertaken between February 1, 1990 and October 31, 1999. Clinical presentation, medical comorbidities, anesthetic agents used, intraprocedural complications, and final procedural outcome were recorded for each patient. Guglielmi detachable coil embolization was attempted in the awake patient in 150 procedures. Among 92 procedures for unruptured aneurysms, 75 (82%) were completed without complications. Four procedures were completed with complications. Of the 92 procedures, 13 were aborted due to patient uncooperativeness (one patient), complications (three patients), morphological characteristics of the aneurysm or surrounding vessels that made embolization technically difficult (eight patients), or vasospasm (one patient). Among 58 procedures for ruptured aneurysms, the procedure was completed without complication in 48 cases (83%). The procedure was completed with complications in five cases and two patients required induction of general anesthesia during the procedure. Five procedures were aborted because morphological characteristics of the aneurysm or surrounding vessels made embolization technically difficult (two patients) or because of aneurysm rupture (two patients) or the appearance of a transient neurological deficit (one patient)., Conclusions: Embolization of intracranial aneurysms performed using GDCs in the awake patient appears to be safe and feasible and allows intraprocedural evaluation of the patient. Potential advantages, including decreased cardiopulmonary morbidity rates, shorter hospital stay, and lower hospital costs, still require confirmation by a direct comparison with other anesthetic procedures.

Object: Results of previous in vitro and in vivo experimental studies have suggested that placement of a porous stent within the parent artery across the aneurysm neck may hemodynamically uncouple the aneurysm from the parent vessel, leading to thrombosis of the aneurysm. For complex wide-necked aneurysms, a stent may also aid packing of the aneurysm with Guglielmi detachable coils (GDCs) by acting as a rigid scaffold that prevents coil herniation into the parent vessel. Recently, improved stent system delivery technology has allowed access to the tortuous vascular segments of the intracranial system. The authors report here on the use of intracranial stents to treat aneurysms involving different segments of the internal carotid artery (ICA), the vertebral artery (VA), and the basilar artery (BA)., Methods: Ten patients with intracranial aneurysms located at ICA segments (one petrous, two cavernous, and three paraclinoid aneurysms), the VA proximal to the posterior inferior cerebellar artery origin (one aneurysm), or the BA trunk (three aneurysms) were treated since January 1998. In eight patients, stent placement across the aneurysm neck was followed (immediately in four patients and at a separate procedure in the remaining four) by coil placement in the aneurysm, accomplished via a microcatheter through the stent mesh. In two patients, wide-necked aneurysms (one partially thrombosed BA trunk aneurysm and one paraclinoid segment aneurysm) were treated solely by stent placement; coil placement may follow later if necessary. No permanent periprocedural complications occurred and, at follow-up examination, no patient was found to have suffered symptoms referable to aneurysm growth or thromboembolic complications. Greater than 90% aneurysm occlusion was achieved in the eight patients treated by stent and coil placement as demonstrated on immediate postprocedural angiograms. Follow-up angiographic studies performed in six patients at least 3 months later (range 3-14 months) revealed only one incident of in-stent stenosis. In the four patients originally treated solely by stent placement, no evidence of aneurysm thrombosis was observed either immediately postprocedure or on follow-up angiographic studies performed 24 hours (two patients), 48 hours, and 3 months later, respectively., Conclusions: A new generation of flexible stents can be used to treat complex aneurysms in difficult-to-access areas such as the proximal intracranial segments of the ICA, the VA, or the BA trunk. The stent allows tight coil packing even in the presence of a wide-necked, irregularly shaped aneurysm and may provide an endoluminal matrix for endothelial growth. Although convincing experimental evidence suggests that stent placement across the aneurysm neck may by itself promote intraluminal thrombosis, the role of this phenomenon in clinical practice may be limited at present by the high porosity of currently available stents.

Object: The risks associated with carotid endarterectomy (CEA) are increased in the presence of contralateral carotid artery (CA) occlusion. The 30-day stroke and death rate for patients in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) who had contralateral CA occlusion was 14.3%. The authors analyze their experience with angioplasty and/or stent placement in patients with contralateral CA occlusion to determine the safety and efficacy of endoluminal revascularization in this subgroup., Methods: Twenty-six procedures were evaluated in 23 patients with high-grade CA stenosis and contralateral CA occlusion. The first 15 procedures were evaluated retrospectively, and the next 11 prospectively. All patients had severe medical comorbidities and were considered too high risk for CEA, even without considering the contralateral occlusion. Clinical follow-up review was performed an average of 18 months later (median 15 months)., Conclusions: The average ipsilateral CA stenosis according to NASCET criteria was 78% preprocedure and 5% postprocedure. There were no changes in neurological or functional outcome immediately postoperatively in any patient. The 30-day postoperative stroke and death rates were zero. However, there was one symptomatic femoral hematoma that resolved without surgery. At follow up, there were three patients who had suffered stroke or death. One patient died secondary to respiratory arrest at 2 months; one died secondary to prostate carcinoma at 12 months; and one patient experienced a minor stroke contralateral to the treated artery at 41 months. Despite the substantial preoperative risk factors in patients in this series, the 30-day stroke and death rate for angioplasty and/or stent placement appears to be lower than that of CEA in patients with contralateral occlusions.

Object: Treatment consisting of percutaneous transluminal angioplasty (PTA) and stent placement has recently been proposed as an alternative to surgical reexploration in patients with recurrent carotid artery stenosis following endarterectomy. The authors retrospectively reviewed their experience after performing 25 procedures in 21 patients to assess the safety and efficacy of PTA with or without stent placement for carotid artery restenosis., Methods: The mean interval between endarterectomy and the endovascular procedures was 57 months (range 8-220 months). Seven arteries in five patients were treated by PTA alone (including bilateral procedures in one patient and repeated angioplasty in the same vessel in another). Early suboptimum results and recurrent stenosis in some of these initial cases prompted the authors to combine PTA with stent placement in the treatment of 18 arteries over the past 3 years. No major periprocedural deficits (neurological or cardiac complications) or death occurred. There was one periprocedural transient neurological event, and in one patient a pseudoaneurysm of the femoral artery (at the access site) required surgical repair. In the 16 patients who each underwent at least 6 months of follow-up review, no neurological events ipsilateral to the treated artery had occurred after a mean follow-up period of 27 months (range 6-57 months). Three of five patients who underwent PTA alone developed significant (>50%) asymptomatic restenoses that required repeated angioplasty in one and PTA with stent placement in two patients. Significant restenosis (55%) was observed in only one of the vessels treated by combined angioplasty and stent placement., Conclusions: Endovascular PTA and stenting of recurrent carotid artery stenosis is both technically feasible and safe and has a satisfactory midterm patency. This procedure can be considered a viable alternative to surgical reexploration in patients with recurrent carotid artery stenosis.

The authors report the occurrence of ipsilateral transient cavernous sinus syndrome during balloon test occlusion (BTO) of the cervical internal carotid artery (ICA) and discuss the involved pathomechanisms. The authors reviewed their series of 129 BTOs of the ICA performed between 1989 and 1996. Two patients developed facial paresthesias and transient palsies of the third through sixth cranial nerves during test occlusion of the cervical ICA. The tests were performed prior to planned permanent carotid artery occlusion for the treatment of a neck sarcoma in one patient and a giant cavernous carotid artery aneurysm in the other. The patients' symptoms resolved with deflation of the balloon. When the balloon was subsequently inflated above the inferior cavernous sinus artery (ICSA), one of the patients complained of mild facial discomfort. There was no contralateral weakness or mental status change during test occlusion in either patient. Angiography demonstrated good filling of the ipsilateral intracranial circulation via collateral vessels of the circle of Willis. In these two cases, the cranial nerves in the cavernous sinus were likely supplied by the ICA via the meningohypophyseal trunk and the ICSA. In each case, there was excellent blood supply to the ipsilateral cerebral hemisphere; however, there was probably inadequate retrograde filling of the cranial nerve collateral vessels located where the meningohypophyseal trunk and ICSA originated. These cases emphasize the importance of a patent external carotid artery-ICA connection for successful cervical carotid artery occlusion. Neurological examination during BTO was critical to interpret the clinical manifestations caused by the hemodynamic changes.

Guglielmi detachable coil (GDC) treatment for complicated cerebral aneurysms is an attractive option that has become widely accepted in recent years. This technique is usually considered only if the patient harbors an aneurysm that is not a good candidate for surgical clipping. However, the definition of "surgical candidate" varies among institutions, and many patients worldwide are being treated with GDCs as primary therapy. Although most centers currently perform follow-up angiography at 6 months to 1 year, others do not routinely perform it after an initially good result. The authors present a case that indicates longer follow up may be necessary and illustrates some of the pitfalls of GDC treatment. This 56-year-old man presented to the emergency room with a Hunt and Hess Grade II subarachnoid hemorrhage and was found to have a wide-necked basilar apex aneurysm. Because of associated medical comorbidities, it was decided to treat the aneurysm with endovascular techniques. The patient did well on follow-up angiography at 1 year postprocedure. However, at approximately 2 years follow up, the aneurysm was demonstrated to have dramatically recanalized and regrown, requiring open surgical intervention. Endovascular coiling was insufficient to treat this aneurysm and complicated definitive surgical management because a large coil mass had been placed in the operative field. It can be inferred from this case that angiographic follow up of these types of lesions may be beneficial up to 2 years after GDC treatment.

A case is presented of severe atherosclerosis of the basilar artery, successfully treated with percutaneous transluminal balloon angioplasty. Crescendo daily transient ischemic attacks consisted of alternating hemiplegia and were refractory to medical management, including anticoagulation therapy. The clinical course, endovascular treatment, and results are described. Prior published experiences with this condition are reviewed.