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Biomedical subjects

Alan S Boulos

Publications and source records attributed to Alan S Boulos.

At least 19 recordsLinked to original sources
PubMed2005

Intraarterial reteplase and intravenous abciximab for treatment of acute ischemic stroke. A preliminary feasibility and safety study in a non-human primate model.

We performed a preliminary feasibility and safety study using intravenous (IV) administration of a platelet glycoprotein IIb/IIIa inhibitor (abciximab) in conjunction with intraarterial (IA) administration of a thrombolytic agent (reteplase) in a primate model of intracranial thrombosis. We introduced thrombus through superselective catheterization of the intracranial segment of the internal carotid artery in 16 primates. The animals were randomly assigned to receive IA reteplase and IV abciximab ( n =4), IA reteplase and IV placebo ( n =4), IA placebo and IV abciximab ( n =4) or IA and IV placebo ( n =4). Recanalization was assessed by serial angiography during the 6-h period after initiation of treatment. Postmortem magnetic resonance (MR) imaging was performed to determine the presence of cerebral infarction or intracranial hemorrhage. Partial or complete recanalization at 6 h after initiation of treatment (decrease of two or more points in pre-treatment angiographic occlusion grade) was observed in two animals treated with IA reteplase and IV abciximab, three animals treated with IA reteplase alone and one animal treated with IV abciximab alone. No improvement in perfusion was observed in animals that received IV and IA placebo. Cerebral infarction was demonstrated on postmortem MR imaging in three animals that received IA and IV placebo and in one animal each from the groups that received IA reteplase and IV abciximab or IV abciximab alone. One animal that received IV abciximab alone had a small intracerebral hemorrhage on MR imaging. IA reteplase with or without abciximab appeared to be the most effective regimen for achieving recanalization in our model of intracranial thrombosis. Further studies are required in experimental models to determine the optimal dose, method of administration and efficacy of these medications in acute ischemic stroke.

Abciximab↗
PubMed2005

Determination of filling volumes in HydroCoil-treated aneurysms by using three-dimensional computerized tomography angiography.

OBJECT: Coil embolization of aneurysms has been shown to be as safe and effective as surgical clip ligation, but has a higher recurrence rate. Advances in coil technology aim to reduce aneurysm recurrence by coating the devices with biological substances. An example of this is MicroVention's HydroCoil, which is a platinum coil coated with hydrogel that improves filling volumes by swelling when it contacts blood. The goal of this study was to determine whether this new coil type significantly reduced or prevented recurrences of aneurysms. METHODS: The authors used three-dimensional computerized tomography angiography to determine aneurysm volumes accurately in 12 patients prior to coil embolization. The percentage filling volume was subsequently calculated for each aneurysm after treatment with HydroCoils and the immediate and 6-month follow-up angiographically confirmed occlusions were evaluated. The data demonstrated that both anterior and posterior intracranial aneurysms with diameters of 3 to 25 mm and volumes of 0.03 to 4.8 ml had filling volumes of 0.02 to 1.36 ml, resulting in filling volumes from 23% in a giant ophthalmic artery aneurysm to 80% in a small anterior communicating artery aneurysm. All of the aneurysms except for the giant one demonstrated stable occlusion on angiographic studies obtained at the 6-month follow-up review. CONCLUSIONS: HydroCoil embolization of intracranial aneurysms is safe and effective for small, large, and very large aneurysms. The percentage filling volume is greater than that reported for bare platinum coils in every case except the giant aneurysm. Nevertheless, angiographically confirmed occlusion is not directly related to percentage filling volume, but rather to the ability to occlude the aneurysm neck.

Cerebral Angiography↗
PubMed2005

Stent placement for the treatment of nonsaccular aneurysms of the vertebrobasilar system.

Vertebrobasilar nonsaccular aneurysms represent a small subset of intracranial aneurysms and usually are among the most challenging to be treated. The aim of this article was to review the literature and summarize the experience in the treatment of these lesions with endovascular approaches. The method of stent implantation as it is performed at the authors' institution, including options available for vertebral artery access, is described. Practitioners involved in the treatment of these lesions should be aware of the potential application of intravascular stent placement as well as the associated postprocedure risks and potential complications.

Basilar Artery↗
PubMed2005

Clinical and angiographic results of dilatation procedures for symptomatic intracranial atherosclerotic disease.

BACKGROUND AND PURPOSE: The authors determined the technical success and the clinical and angiographic results of angioplasty and/or stent placement for intracranial atherosclerotic disease (ICAD) at a tertiary-care referral hospital. METHODS: Angiographic and clinical outcomes occurring within the 1-month follow-up interval were recorded. Patients were followed up for a mean period of 20.5 +/- 9.2 months, and a neurovascular imaging study was performed in 18 of the 21 patients alive after a mean period of 19.7 +/- 9.2 months. Stroke-free survival and ipsilateral stroke-prevention rates were estimated using Kaplan Meier analyses. RESULTS: Twenty-four patients (mean age = 61.0 +/- 13.5 years; 15 were men) underwent 30 procedures for treatment of ICAD. The procedures included angioplasty (n = 18) and attempted primary stent placement (n = 14). In 2 procedures, angioplasty was performed in the same session after unsuccessful stent placement. There was immediate stenosis reduction (mean +/- SD) from 84% +/- 17% to 27% +/- 21%. The overall 1-month composite rate of major stroke, death, and major bleeding complications was 7% for the 30 procedures. Overall stroke-free survival at 36 months was estimated as 79% (95% confidence interval, 57%-91%), and the ipsilateral stroke-prevention rate was estimated to be 87% (95% confidence interval, 65%-95%). Among the 15 patients who underwent repeat angiography, restenosis requiring second intervention was observed in 1 patient. No restenosis could be identified in 3 patients who underwent computed tomographic or magnetic resonance angiography. CONCLUSION: This single-center study demonstrates the feasibility and effectiveness (for secondary stroke prevention) of angioplasty and/or stent placement for treatment of ICAD.

Angiography, Digital Subtraction↗
PubMed2005

Preliminary evidence supporting the safety of drug-eluting stents in neurovascular disease.

OBJECTIVE: Restenosis is a significant complication of stent placement. With coronary revascularization, drug-eluting stents have significantly decreased the incidence of in-stent stenosis and, therefore, the morbidity of the procedure. Restenosis is potentially a significant problem for neurovascular disease. We therefore report our institutional experience on the use of drug-eluting stents for the management of cerebrovascular insufficiency. METHODS: Over a period of 2 years, 19 patients underwent extra- and intracranial drug-eluting stent placement for intra- and extracranial atherosclerotic disease. There were 12 males and seven females aged between 36 and 83 years old (mean 65). Thirteen heparin, three rapamycin, and three taxus-coated stents were placed. There were five intracranial internal carotid arteries, two intracranial vertebral arteries, three mid-basilar, six of vertebral artery origin and three middle cerebral artery stents utilized. No complications occurred. RESULTS: There was one case of re-stenosis associated with recurrent symptoms requiring repeat drug eluting stent placement. No other patients have developed new or recurrent neurological symptoms. Five of six vertebral artery origin stents were placed with distal protection to prevent embolic complications. CONCLUSION: Intracranial and extracranial drug-eluting stent placement appears to be a safe alternative to the medical management of atherosclerotic disease of the vertebrobasilar and carotid systems. However, further randomized studies are needed to examine the effectiveness and safety of this procedure.

Adult↗
PubMed2005

Coronary angiojet catheterization for the management of dural venous sinus thrombosis. Technical note.

In most cases of deep venous sinus thrombosis, systemic anticoagulation represents the initial treatment of choice for preventing propagation of a clot in the dural sinuses. In patients with deep or extensive venous sinus thrombosis, a combination of treatment modalities may be required including systemic anticoagulation, selective venous thrombolysis, and mechanical thrombectomy. In the current study the authors report on a patient who presented with the acute onset of headache, vomiting, a depressed level of consciousness, and a left hemiparesis and in whom a right middle cerebral artery (MCA) territory ischemic stroke with hemorrhagic conversion was initially diagnosed. Results of diagnostic cerebral angiography demonstrated a patent right MCA and a deep venous sinus thrombosis involving most of the dural sinuses. Despite adequate systemic heparinization, the patient's neurological condition deteriorated and direct administration of alteplase into the transverse sinus in conjunction with mechanical clot disruption using a coronary AngioJet was required. Venous flow was successfully reestablished in the deep and superficial venous sinuses by using a 0.014-in exchange wire routed from the right common femoral vein through the sinuses and out the left common femoral vein. Excellent angiographic results were obtained, and the patient had recovered completely by the 7-month follow up.

Adult↗
PubMed2005

A triple bifurcation aneurysm model for evaluating complex endovascular therapies in dogs.

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.

Anastomosis, Surgical↗
PubMed2004

Safety of high-dose intravenous eptifibatide as an adjunct to internal carotid artery angioplasty and stent placement: a prospective registry.

OBJECTIVE: Eptifibatide, a competitive platelet glycoprotein IIb-IIIa receptor inhibitor with high selectivity for platelet glycoprotein IIb-IIIa receptors and a short half-life, has been shown to reduce the risk of ischemic events associated with coronary interventions, particularly when used in high doses. However, its role in conjunction with neurointerventional procedures needs to be determined. We report the results of an open-label prospective registry to evaluate the safety (in terms of avoiding hemorrhagic complications) and effectiveness (in terms of preventing ischemic complications such as stroke) of administering high-dose eptifibatide during internal carotid artery angioplasty and stent placement (CAS) for extracranial carotid artery stenosis. METHODS: After femoral artery access was established and intravenous heparin (30 U/kg bolus) was administered, each patient was administered intravenous eptifibatide (two 180-microg/kg single-dose boluses before CAS, then a 2.0-microg/kg/min infusion for 20-24 hours thereafter). The primary end point was the 30-day composite occurrence of death, cerebral infarction, and unplanned or urgent endovascular or surgical intervention. The primary safety end point was bleeding, for which complications were classified according to the Thrombolysis in Myocardial Infarction scheme as major (hemoglobin decrease of more than 5 g/dl), minor (hemoglobin decrease of 3-5 g/dl), or insignificant. Platelet aggregation was measured in 13 consecutive patients with a rapid platelet-function analyzer. RESULTS: Twenty-six patients (mean age, 68.1 +/- 9.4 yr; 16 men) underwent treatment. The infusion and the CAS procedure were discontinued in one patient who developed angioneurotic edema after being administered intravenous heparin and the first bolus dose of eptifibatide. Among the 25 patients who underwent the procedure, no intracerebral hemorrhages and one minor ischemic stroke occurred during the 1-month follow-up period. The minor stroke was observed on postprocedure Day 7 in a patient for whom antiplatelet therapy was discontinued before a coronary artery bypass graft operation was performed. Another patient was discharged after an uncomplicated hospitalization but died as a result of urinary sepsis 12 days after CAS. One episode of major bleeding from the femoral insertion site required surgical repair and blood transfusions. Minor bleeding occurred in one patient. Platelet aggregation measurements obtained in 13 patients revealed a high degree (mean, 96%; range, 86-100%) of platelet inhibition after the administration of the second bolus dose of intravenous eptifibatide. CONCLUSION: High-dose eptifibatide administered as an adjunct to CAS seems to be safe. Further studies are required to analyze its effectiveness and role in neurointerventional procedures.

Adult↗
PubMed2004

Evolution of neuroendovascular intervention: a review of advancement in device technology.

Neuroendovascular surgery is a rapidly evolving field. Each year, numerous improvements are made in the endovascular surgeon's armamentarium. This evolution in technology, which is occurring at a dizzying pace, addresses many of the current limitations of neuroendovascular approaches. The potential to improve the outcomes of our patients is tremendous, particularly because one of the most common and most devastating neurological disorders, ischemic stroke, remains largely untreated. This article presents several of the new technologies that are currently being investigated or are under development and have the potential to lead to major advances in endovascular approaches for the treatment of intracranial and extracranial diseases.

Angioplasty↗
PubMed2004

Sirolimus-eluting stents in the canine cerebral vasculature: a prospective, randomized, blinded assessment of safety and vessel response.

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.

Animals↗
PubMed2004

Preoperative stent placement for intradural vertebral artery stenosis from a rare xanthogranuloma. Case report.

In this report, the authors discuss a novel use of intradural vertebral artery (VA) stent placement to protect a tumor-encased vessel from injury during lesion resection. The tumor was a rare foramen magnum region xanthogranuloma and a component of Erdheim-Chester disease (ECD). This 64-year-old man presented with large masses encasing and compressing the intracranial segments of each VA. Preoperatively, a left VA stent was placed to protect the arterial wall during resection of the tumor. Histopathological study results on the subtotally resected mass were consistent with xanthogranuloma, a rare benign histiocytic tumor frequently occurring in patients with ECD. Further radiographic evaluation in the patient revealed an osteolytic lesion of the eleventh thoracic vertebra supporting the diagnosis of ECD disease. Based on this case study, the authors recommend the following: 1) tumor-encased vessels can be protected preoperatively by stent placement to assist with tumor debulking; and 2) patients diagnosed with a xanthogranuloma should be evaluated for multisystem involvement consistent with ECD.

Angioplasty, Balloon↗
PubMed2004

Reocclusion of recanalized arteries during intra-arterial thrombolysis for acute ischemic stroke.

BACKGROUND AND PURPOSE: Early reocclusion of recanalized arteries has been observed after thrombolysis for acute coronary occlusion and has been attributed to platelet activation after exposure to thrombolytic agents. We conducted a retrospective study to determine the rate of reocclusion during intra-arterial thrombolysis for acute ischemic stroke and the effect of reocclusion on functional outcome. METHODS: Patients treated for acute ischemic stroke at our center between September 2000 and May 2002 received a maximum total dose of 4 U of reteplase intra-arterially in 1-U increments via superselective catheterization. Pharmacologic thrombolysis was supplemented by mechanical thrombolysis with balloon angioplasty or snare manipulation at the occlusion site. Angiography was performed after each unit of reteplase or mechanical maneuver, and the images were interpreted by a blinded reviewer. Reocclusion was defined as partial or complete initial recanalization with occlusion recurring at the same site as documented by angiography during the endovascular treatment. Reocclusions were treated by further pharmacologic and/or mechanical thrombolysis according to the discretion of the treating physician. Clinical evaluations were performed before and 24 hr, 7 to 10 days, and 1 to 3 months after treatment. RESULTS: Forty-six consecutive patients underwent intra-arterial thrombolysis. Reocclusion was observed in eight (17%). Among these patients, initial sites of occlusion were in the following arteries: intracranial internal carotid artery (n = 2), M1 segment of the middle cerebral artery (n = 3), M1 and M2 segments of the middle cerebral artery (n = 2), and basilar artery (n = 1). The mean initial National Institutes of Health Scale score for these eight patients was 23.3 +/- 6.2; mean time from symptom onset to treatment was 4.4 +/- 1.2 hr. The reocclusions were treated by using additional doses of reteplase alone (n = 1), reteplase with snare maneuver and/or angioplasty (n = 5), reteplase with angioplasty or snare and then stent placement (n = 1), and angioplasty with stent placement (n = 1). The reocclusions resolved in six of eight patients after further treatment. Six patients died and two survived but were severely disabled at 1 month (modified Rankin Scale scores of 4 and 5, respectively). Independent functional outcome scores (modified Rankin Scale scores of 0-2) were significantly lower among patients with angiographically shown reocclusion than in those without (0 of 8 versus 17 of 38, P =.02). CONCLUSION: Reocclusion occurs relatively frequently during intra-arterial thrombolysis for ischemic stroke and seems to be associated with poor clinical outcomes.

Acute Disease↗
PubMed2003

Fate of branch arteries after intracranial stenting.

OBJECTIVE: One concern with respect to stent procedures performed to treat patients with intracranial lesions is the fate of normal major arterial branches after stents are placed across them. Because most of these lesions occur at vessel bifurcations or at branch points, a normal major branch often arises near the lesion and may be difficult to avoid during stent positioning. The aim of this article is to describe the angiographic outcome of intracranial major branch arteries crossed by a stent in the intracranial circulation. METHODS: We examined the immediate postprocedural cerebral angiograms of the 40 patients who underwent intracranial stenting at the University at Buffalo, Buffalo, NY, between June 1998 and April 2000. In each of 10 patients, the stent was placed across a normal major branch artery. Stents were used to treat aneurysms in seven patients and intracranial stenosis in three patients. The latest cerebral angiogram available was reviewed, and the patency of the major branch arteries was evaluated. RESULTS: The angiographic follow-up period ranged from 4 days to 35 months (mean follow-up, 10 mo). Each of the 10 major branch arteries was patent. No infarcts were associated with the territory of the major branch arteries crossed by the stents, and no patient experienced a related episode of clinical ischemia. Four patients died as a result of causes unrelated to the stenting procedure. The histology of a middle cerebral artery stent that was placed across a lenticulostriate perforator is presented. CONCLUSION: The flexible, low-profile stents used in this study had no angiographically or clinically apparent effect on the major intracranial branches across which they were placed.

Adult↗
PubMed2003

In vivo model of intracranial stent implantation: a pilot study to examine the histological response of cerebral vessels after randomized implantation of heparin-coated and uncoated endoluminal stents in a blinded fashion.

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.

Angiography↗
PubMed2003

Intracranial stent placement for the treatment of a carotid-cavernous fistula associated with intracranial angioplasty. Case report.

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.

Aged↗
PubMed2003

Comparison of periprocedure complications resulting from direct stent placement compared with those due to conventional and staged stent placement in the basilar artery.

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.

Aged↗
PubMed2003

Cutting balloon to treat carotid in-stent stenosis: technical note.

Carotid artery in-stent stenosis, a possible long-term complication of carotid angioplasty and stenting, is currently treated by inflation of a non-compliant angioplasty balloon. Better initial results and less recurrence of stenosis have been documented in the coronary literature with the use of the Cutting Balloon (CB, Boston Scientific Interventional Technologies, San Diego, California) for angioplasty, in comparison with traditional balloon angioplasty. We report our collective experience with the use of the CB to treat carotid in-stent stenosis in three patients. Excellent angiographic and clinical results were achieved. No complications occurred. The lesions in two patients were successfully treated with the CB alone; adjunctive stent placement was required in a third patient. Our experience demonstrates the feasibility and safety of the CB for the treatment of carotid in-stent stenosis in three patients. Due to the less traumatic nature of this balloon, its use may result in a lower occurrence of in-stent stenosis as compared to a conventional angioplasty balloon. To our knowledge, this is the first report of the use of the CB for carotid in-stent stenosis.

Adult↗