Retinoids downregulate vascular endothelial growth factor/vascular permeability factor production by normal human keratinocytes

PURPOSE: We describe the clinical presentation, angiographic findings, and clinical outcome in a group of patients with pseudoaneurysms treated by a new endovascular technique using Guglielmi electrolytically detachable platinum coils (GDCs). METHODS: We retrospectively reviewed the angiographic and clinical findings in a series of 11 patients with pseudoaneurysms occurring in a variety of locations: seven in the cavernous carotid artery, one in the petrous carotid artery, two in the anterior cerebral artery, and one in the cervical vertebral artery. RESULTS: All aneurysms were cured with GDC embolization. The only complication was a branch occlusion, which resolved with heparinization and produced no clinical sequelae. CONCLUSION: Pseudoaneurysms can be safely and effectively treated by embolization with GDCs. Consideration needs to be given to the anatomic location of the pseudoaneurysm and the acuity of onset. Treatment efficacy may by improved if there are bony confines around the aneurysm or if therapy takes place in the subacute period, when the wall of the pseudoaneurysm has matured and stabilized.     

Complex intracranial aneurysms: combined operative and endovascular approaches

OBJECTIVE: Endovascular management of complex intracranial aneurysms is increasingly being considered as an alternative to standard surgical clipping. However, little attention has been paid to the complementary nature of surgery and endovascular therapy. METHODS: Between September 1992 and May 1997, 12 patients with complex intracranial aneurysms were treated with combined operative and endovascular methods. Seven patients demonstrated subarachnoid hemorrhage (two of Grade II, two of Grade III, and three of Grade IV). Five patients demonstrated unruptured aneurysms, i.e., three giant aneurysms (one vertebrobasilar junction aneurysm, one middle cerebral artery bifurcation aneurysm, and one internal carotid artery-ophthalmic artery aneurysm), one large internal carotid artery-ophthalmic artery aneurysm, and one middle cerebral artery serpentine aneurysm. Management strategies involved either surgery followed by endovascular therapy (S-E; n = 5) or endovascular therapy followed by surgery (E-S; n = 7). S-E paradigms included aneurysm exploration followed by endovascular treatment (S-E1; n = 3), partial aneurysm clipping followed by endovascular aneurysm packing (S-E2; n = 1), and extracranial-to-intracranial bypass followed by endovascular parent vessel occlusion (S-E3; n = 1). E-S paradigms included superselective angiography followed by surgical clipping (E-S1; n = 2), Guglielmi detachable coil partial dome packing followed by delayed surgical clipping (E-S2; n = 2), proximal temporary vessel balloon occlusion followed by aneurysm clipping (E-S3; n = 2), and proximal permanent vessel occlusion followed by surgical aneurysm decompression for mass effect treatment (E-S4; n = 1). RESULTS: Eleven aneurysms (92%) were completely eliminated. The remaining aneurysm was 90% obliterated and remained quiescent at the 34-month follow-up examination, despite presenting with subarachnoid hemorrhage. No patient experienced repeat bleeding (follow-up period, 23+/-28 mo). There were no deaths. One patient achieved a fair outcome (Glasgow Outcome Scale score of III); all other patients experienced excellent outcomes (Glasgow Outcome Scale score of I). In all cases, the aneurysm management paradigm chosen had a positive effect on definitive therapy. CONCLUSION: Several factors can contribute to the complexity of intracranial aneurysms. Management strategies that combine operative and endovascular techniques in a complementary way, for the best possible outcomes for these patients, can be designed accordingly.     

Angioplasty of the occluded internal carotid artery

PURPOSE: To review patients who have presented with acute strokes from a middle cerebral artery occlusion in whom in addition to the middle cerebral artery thromboembolus, an internal carotid artery occlusion has been present, and in whom angioplasty of these totally occluded internal carotid arteries has bee n successful. METHODS: We reviewed retrospectively our experience in treating a cute stroke patients with intracranial, intraarterial urokinase. Six of 27 patients had internal carotid artery occlusions in addition to middle cerebral artery occlusions. Two patients presented with spontaneous carotid dissections for wh ich no further intervention from the ipsilateral internal carotid artery was attempted. In the remaining four internal carotid artery occlusions secondary to atherosclerotic disease, standard guide wires and catheters were negotiated across the level of the internal carotid artery occlusion, which expedited intracranial catheterization for thrombolysis. Subsequently, angioplasty of the internal carotid artery was performed. RESULTS: All four occluded internal carotid arteries could be traversed. No new neurologic deficits occurred. No vascular injuries occurred. No deaths occurred. Four- to 6-month follow-up showed all four internal carotid arteries remained patent. CONCLUSION: In acute occlusions of the internal carotid artery from atherosclerosis, the occluded vessel can sometimes be recanalized with low morbidity. In addition, endovascular access to the intracranial circulation can be expedited by using the recanalized internal carotid artery.     

Intravascular stent and endovascular coil placement for a ruptured fusiform aneurysm of the basilar artery. Case report and review of the literature

The authors demonstrate the technical feasibility of using intravascular stents in conjunction with electrolytically detachable coils (Guglielmi detachable coils [GDCs]) for treatment of fusiform, broad-based, acutely ruptured intracranial aneurysms and review the literature on endovascular approaches to ruptured aneurysms and cerebral stent placement. A 77-year-old man presented with an acute subarachnoid hemorrhage of the posterior fossa. A fusiform aneurysm with a broad-based neck measuring 12 mm and involving the distal vertebral artery (VA) and proximal third of the basilar artery (BA) was demonstrated on cerebral angiography. The aneurysm was judged to be inoperable. Six days later a repeated hemorrhage occurred. A 15-mm-long intravascular stent was placed across the base of the aneurysm in the BA and expanded to 4 mm to act as a bridging scaffold to create a neck. A microcatheter was then guided through the interstices of the stent into the body and dome of the aneurysm, and GDCs were deposited for occlusion. The arteriogram obtained after stent placement demonstrated occlusion of the main dome and body of the aneurysm. The coils were stably positioned and held in place by the stent across the distal VA and BA fusiform aneurysm. Excellent blood flow to the distal BA and posterior cerebral artery was maintained through the stent. There were no new brainstem ischemic events attributable to the procedure. No rebleeding from the aneurysm had occurred by the 10.5-month follow-up evaluation, and the patient has experienced significant neurological improvement. Certain types of intracranial fusiform aneurysms may now be treated by combining intravascular stent and GDC placement for aneurysm occlusion via an endovascular approach. This is the first known clinical application of this novel approach in a ruptured cerebral aneurysm.     

Canine fucosidosis: a model for retroviral gene transfer into haematopoietic stem cells

To investigate the role of endovascular treatment we performed a retrospective study of our patients with multiple intracranial aneurysms seen in our institution between October 1992 and March 1995. This period was chosen to study a homogeneous group of patients since the appearance of controlled detachable coils, and to obtain the largest number of patients with angiographic follow-up of the aneurysms treated. We studied 53 patients with a total of 128 aneurysms, in 46 of whom we treated 67 aneurysms by the endovascular approach. Of these, 5 aneurysms in 3 patients were treated by occlusion of the parent vessel and 62 aneurysms in 43 patients with coils, 52 with Guglielmi detachable coils and 10 with mechanically detachable spirals. Complete occlusion was obtained in 58 aneurysms, and partial occlusion in 9. The therapy caused permanent neurological deficit in 3 cases (6.5%), and there was 1 case of rebleeding (incomplete occlusion of the aneurysm). No deaths occurred. All aneurysms were treated in 29 of the 53 patients. Endovascular procedures were used for 16 patients (30%), surgery was performed in 1 patient (2%) and the two were combined in 12 (23%). In 23 of 53 cases (43%), unruptured aneurysms were left untreated, usually because of their small size. In 1 patient with unruptured aneurysms, the endovascular approach failed and the patient refused surgery.     

Intraoperative high-dose regional urokinase infusion for cerebrovascular occlusion after carotid endarterectomy

Operative stroke complicating carotid endarterectomy is traditionally treated by reexploration of the operative site to correct a potentially causative lesion; however, attempts are not made to diagnose or treat the intracranial arterial occlusion. A 65-year-old man had a right hemiplegia during a left carotid endarterectomy that was caused by premature reversal of heparin, which resulted in thrombosis of his left anterior cerebral artery. On reexploration, the patient was treated with a 1-hour infusion of 1 million U urokinase through an indwelling carotid shunt. A repeat arteriogram demonstrated patency of the left anterior cerebral artery, with complete clot dissolution and resolution of the right hemiplegia on awakening. Natural history studies of stroke and prospective, angiographically controlled clinical trials of intraarterial thrombolytic therapy for acute stroke support the use of intraoperative intraarterial infusion of urokinase as part of a therapeutic approach to patients who have an ischemic stroke during carotid endarterectomy.     

New interventions in cerebrovascular disease: the role of thrombolytic therapy and balloon angioplasty

The use of thrombolytic agents (plasminogen activators) in the early moments of ischemic stroke to achieve recanalization and potential neurologic improvement has been actively studied over the past 10 years. In the same period, endovascular techniques for cerebral revascularization have evolved significantly. Recent phase III studies, following angiography-based phase I and II studies of plasminogen activators in stroke, have described evidence of clinical benefit and contributors to morbidity (i.e., symptomatic hemorrhage) and mortality that limit the applicability of this approach. The limited formalized experience with percutaneous transluminal balloon angioplasty and stent placement in the carotid artery and cerebral circulation has given rise to concerns about the safety and appropriateness of the procedures in this territory. However, several prospective series support the feasibility of well-designed clinical trials.     

Fibrinolytic therapy of acute cerebral infarct

On the basis of our upon own results of local intra-arterial fibrinolysis (LIF), this article gives a short overview of recently established thrombolytic therapy in acute ischemic stroke. Fifty patients with acute occlusions of vertebrobasilar arteries and 118 patients showing occlusions of branches of the internal carotid artery were treated with LIF. The Occlusion type, occlusion site and successful recanalization were associated with a favorable outcome: 92% of embolic occlusions in the vertebrobasilar territory were recanalized and resulted in 50% in a favorable outcome. In the carotid territory, optimal outcome was achieved in main stem and branch occlusions of the middle cerebral artery, due to recanalization rates of 49%-64%. In contrast, occlusions of the intracranial bifurcation of the carotid artery (carotid-"T") resulted in death in 59%. Despite the lack of randomized trials, LIF is an established form of therapy in the vertebrobasilar territory. In the carotid territory randomized clinical studies could demonstrate the efficacy of intravenous fibrinolytic therapy in some stroke patients. It can be presumed from pilot studies that LIF is superior to the intravenous version in the carotid territory.     

Neurosurgical management of cerebral aneurysms following unsuccessful or incomplete endovascular embolization

Modern endovascular techniques permit treatment of intracranial aneurysms in many circumstances when surgery is associated with significant morbidity. Occasionally, embolization of aneurysms is unsuccessful or incomplete or followed by complications, in which case surgical management is required. Since 1986, 196 patients have undergone embolization of intracranial aneurysms at the authors' institution and 21 (11%) required subsequent surgical treatment. Attempted embolization failed in five patients (Group A). Ten patients (Group B) had only partial occlusion of the aneurysm or demonstrated recanalization on follow-up studies. Eight of these Group B patients underwent embolization with Guglielmi detachable coils (GDCs), representing 5.7% of the 141 GDC-treated patients in this experience. Surgical treatment in these two groups consisted of clipping (eight cases), surgical parent vessel occlusion (one case), and parent vessel occlusion with extracranial-intracranial bypass (six cases). Fourteen (93%) of the 15 patients in these two groups had an excellent or good outcome with complete aneurysm occlusion. Six patients underwent surgery to treat complications related to the endovascular procedure (Group C). Of these, four patients had neurological improvement compared to their preoperative state, and two died. This series of cases demonstrates that surgical treatment of aneurysms is usually possible with good results following incomplete embolization and emphasizes the need for close and continued neurosurgical involvement in the endovascular management of intracranial aneurysms.     

Thrombolytic therapy in acute occlusion of the intracranial internal carotid artery bifurcation

PURPOSE: To evaluate efficacy and clinical benefit of early thrombolytic therapy in intracranial internal carotid artery occlusion. METHODS: Thirty-two patients (mean age, 56 years) with acute intracranial internal carotid artery occlusion were studied clinically and with CT and angiography before and after thrombolytic therapy with intravenous alteplase (n = 16), superselective intraarterial alteplase (n = 8), and superselective intraarterial urokinase (n = 8). RESULTS: Initial CT showed a large parenchymal hypodensity in 11 (34%) patients, a small hypodensity in 15 (47%) patients, and no hypodensity in 6 (19%) patients. Recanalization after thrombolytic therapy was observed in 4 patients (12.5% in each treatment group). Follow-up CT showed six hemorrhagic infarcts and four parenchymal hematomas unrelated to recanalization, alteplase, or urokinase administration, but commonly associated with intraarterial treatment. Clinical outcome was fatal in 53%, poor in 31%, and moderate or good in 16% of the patients. Outcome was equal in different treatment groups and closely linked to both the quality of leptomeningeal collaterals and the extent of parenchymal hypodensity on the first CT. CONCLUSION: Because intravenous or intraarterial treatment with alteplase or urokinase fails to recanalize the vascular obstruction, it does not improve the prognosis of intracranial internal carotid artery occlusion over that of the natural course. Improved results may be possible with novel recanalization techniques.     

Endovascular treatment of acute thrombotic occlusion of the cervical internal carotid artery associated with embolic occlusion of the middle cerebral artery: case report

A 68-year-old man with acute, total thrombotic occlusion of the right cervical internal carotid artery, associated with embolic occlusion of the ipsilateral middle cerebral artery, was treated by the endovascular approach, i.e., intra-arterial fibrinolysis and balloon angioplasty. Endovascular treatment for a totally occluded internal carotid artery is indicated in the very early stage where there is no thrombus or a short thrombus that can be evacuated. Fibrinolysis of the associated embolus in the middle cerebral artery, if any, can be done in the same session, enabling an early restoration of the blood flow.     

Saccular intracranial aneurysms: endovascular treatment with mechanical detachable spiral coils

PURPOSE: To evaluate endovascular treatment of saccular intracranial aneurysms with mechanical detachable spiral coils. MATERIALS AND METHODS: Fifty-three patients with 56 saccular aneurysms underwent endovascular treatment with spiral coils. All but five had symptomatic subarachnoid hemorrhage staged according to the Hunt and Hess classification as follows: stage IV or V (n = 20), stage III (n = 10), stage I or II (n = 20), and stage 0 (asymptomatic [n = 6]). RESULTS: Forty-seven aneurysms were occluded (100% occlusion) on follow-up angiograms with the following time distribution: 24 months for six aneurysms (six patients), 12 months for 14 aneurysms (11 patients), 6 months for 13 aneurysms (13 patients), 4 months for four aneurysms (four patients), and only immediate postprocedure study for 16 aneurysms (16 patients) (excludes two deaths and one failure). CONCLUSION: In this relatively small group, endovascular treatment with mechanical detachable spiral coils had a success rate of 90%, and it appears to be a rapid, reliable, and relatively safe technique in the treatment of life-threatening subarachnoid hemorrhage.     

Future endovascular management of cerebral aneurysms

The endovascular management of cerebral aneurysms is undergoing revolutionary growth. Recent advances in endovascular surgery including balloon remodeling, revascularization techniques, functional cerebral rearrangement, intracranial stents, treatment for vasospasm and coil design are discussed, as are their future considerations.     

Effect of Guglielmi detachable coils on experimental carotid artery aneurysms in primates

BACKGROUND AND PURPOSE: Clinical experience has established that intravascularly placed metal coils can be a useful treatment for cerebral vascular aneurysms. However, the mechanism by which the coils induce occlusion of the aneurysm is unclear. Appropriate use of this promising treatment modality requires basic understanding of the occlusive process. We used an animal model system of experimentally induced carotid aneurysms to investigate the initial events induced by Guglielmi detachable coils (GDCs), as well as the subsequent vascular changes induced by the coils over time. METHODS: We induced 23 aneurysms in the carotid arteries of 16 Japanese monkeys. Nineteen aneurysms were then occluded with GDCs placed via endovascular surgery; 4 aneurysms served as controls. We then used gross and microscopic pathological examination, angiography, and scanning electron microscopy to assess the effects of the GDC. RESULTS: In the first few hours after placement of the GDC in the experimental aneurysms, we observed leukocyte attachment and deposition of fibrinlike materials and other proteins. By 4 days after coil placement, leukocytes and fibroblasts were observed in the thrombus. By 2 weeks after coil placement, there was evidence of an endothelial-like covering of the coils. At 3 months after coil placement, we observed development of an arterial media in the occluded aneurysms. CONCLUSIONS: The GDCs initiated a cellular response within several hours of aneurysm occlusion. By 2 weeks after coil placement, endothelialization was proceeding, and by 3 months after occlusion, remodeling of the aneurysm had progressed to produce a media-like structure in the former aneurysm.     

Endosaccular occlusion of basilar artery bifurcation aneurysms using electrically detachable coils

Thirteen patients with basilar artery bifurcation aneurysms, treated by electrothrombosis using electrically detachable coils, are presented. Nine of them presented after hemorrhage, two with mass effect, and two were found coincidentally with other ruptured aneurysms. Selection for endovascular therapy was based on the following criteria: 1) poor clinical condition (Hunt and Hess III-V); 2) high surgical risk; 3) age and poor medical condition; 4) morphological features (small necked aneurysms). With endovascular Guglielmi detachable coils aneurysm occlusion ranging from 70-100% was achieved in all cases. All five small necked and two large broad necked aneurysms were totally occluded. Two large aneurysms had a 95% occlusion and two other large aneurysms were 90% occluded. In another patient with a large broad based aneurysm only an 80% occlusion was achieved, because of tortuosity of the vertebrobasilar system. Our last patient, who presented as grade V clinically, was partially treated with a 70% aneurysmal occlusion. The clinical results were excellent in 10 and good in 2. The only poor outcome was seen in the grade V patient. There was no morbidity or mortality related to therapy. The only complication was an asymptomatic dissecting aneurysm at the origin of the vertebral artery. Angiographic follow up time ranged from 6 to 20 months with a mean of 9 months. Four patients were treated too recently to have their angiographic follow up at 6 months. Two patients were lost to follow up. Clinical follow up ranged from 1 to 17 months with a mean of 8.9 months. The analysis of our cases clearly shows that aneurysms, which were densely packed with coils, especially if small necked, were less likely to be reperfused and showed a longlasting stable result. Large broad based aneurysms were more likely to be reopened by blood flow after the first procedure, especially if loosely filled with coils, and needed up to 3 interventions to achieve a satisfying result, whereas later in the series a high percentage rate of occlusion was seen after the first procedure. We consider now also a less than 100% occlusion acceptable, because most of the aneurysms will rupture at the dome, which was occluded in all our cases. We conclude, that this new endovascular method is a viable alternative in the treatment of posterior circulation aneurysms with a high surgical risk, in old patients and those in poor clinical and medical condition.     

Microwave disinfection of denture base materials colonized with Candida albicans

OBJECT: Guglielmi detachable coil (GDC) technology is a valuable therapeutic alternative to the surgical treatment of ruptured or incidental intracranial aneurysms. The authors describe their technical and clinical experience in the use of the GDC technique in patients who underwent endovascular occlusion for the treatment of incidentally found intracranial aneurysms. METHODS: One hundred fifteen patients with 120 incidentally found intracranial aneurysms underwent embolization by means of the GDC endovascular technique. Ninety-one patients were females and 24 were males. Patient age ranged from 13 to 80 years. In 64 patients the incidental aneurysms were discovered when unrelated nonneurological conditions signaled the need for angiography or magnetic resonance angiography (Group 1). Twenty patients who presented with incidental aneurysms that were discovered during treatment for an acutely ruptured aneurysm underwent treatment of both types of aneurysm during the acute phase of subarachnoid hemorrhage (SAH) (Group 2). Sixteen patients with incidental aneurysms were treated during the chronic phase of SAH (Group 3). Group 4 included 15 patients who had incidental aneurysms associated with brain tumors or arteriovenous malformations. Angiographic results revealed complete or near-complete occlusion in 109 aneurysms (91%) and incomplete occlusion in five aneurysms (4%). Guglielmi detachable coil embolization was attempted unsuccessfully in six aneurysms (5%). One hundred nine patients (94.8%) remained neurologically intact or unchanged from their initial clinical status. Five patients (4.3%) deteriorated as a result of immediate procedural complications. All these complications occurred in the first 50 patients treated in the series. No clinical complications were observed in the last 65 patients. In one patient, a partially embolized aneurysm ruptured 3 years postprocedure. In Groups 1 and 3, the average length of hospitalization was 3.3 days. CONCLUSIONS: The evolution of GDC technology has proved to provide safe treatment of incidental aneurysms (a morbidity rate of 0% was achieved in the last 65 patients). The topography of the aneurysm and the clinical condition of the patient did not influence final anatomical or clinical outcomes. The GDC technology also confers a positive economic impact by decreasing hospital length of stay and by eliminating the need for postembolization intensive care.     

The endovascular treatment of cerebral arteriovenous aneurysms and malformations

Despite the progress made in cerebral aneurysm microneurosurgery, some morphologic and anatomic characteristics, or also clinical reasons, make surgical clipping of the aneurysmatic column difficult or unfeasible, justifying an endovascular therapeutic alternative. Despite the great progress made, the risk of endovascular intervention with microballoons is significant, particularly in the acute post-haemorrhagic phase: 17.9% mortality and 10.7% morbidity in endosaccular embolisation therapy with the detachable balloon maintaining the arterial lumen permeable. The use of the GDC system (Guglielmi Detachable Coil) has permitted the treatment of proximal and distal aneurysms in the carotid and vertebrobasilar arterial regions. Microcatheterisation also allows intravascular treatment of the vasospasm, by mechanical means--angioplasty, or by pharmacological vasodilatation. With the GDC system one can obtain a complete occlusion of small and medium aneurysms in over 85% of cases, definitive morbidity of 5% to 7% and mortality of 1% to 3%. The objective of AVM endarterial occlusions is to obliterate the nidus through the arterial pedicles that can be microcatheterised by means of a certain embolic agent (Cyanocrilate, PVA or other embolic products). Thus, it is possible to reduce the dimension of the nidus as well as diminish the severity of the arteriovenous shunt, later facilitating the operation or radiosurgery, with the possibility of complete surgical removal in 96% of patients after embolisation. The mortality directly related to this endovascular therapy is approximately 0.9% with severe morbidity below 2%. Complete obliteration of a cerebral AVM can be achieved with endovascular techniques in 15% to 20% of cases, particularly in small lesions, sustain AVMs require careful multidisciplinary discussion aimed at finding the best treatment for each case.     

The placebo in modern medicine

PURPOSE: To report the results of balloon angioplasty in recurrent carotid occlusive disease and evaluate the potential for stent implantation. METHODS AND RESULTS: Between April 1991 and September 1995, 15 patients with carotid restenosis underwent 17 endoluminal procedures in 3 common carotid and 14 internal carotid arteries. Two postdilation complications (dissection and acute occlusion) required prompt stenting; one common carotid artery was stented for postdilation residual stenosis. One recurrent lesion was also stented 6 months after initial angioplasty. One stroke, 1 silent cerebral infarction, and 3 transient ischemic attacks occurred in the balloon angioplasty patients (33% neurological complication rate). The common carotid stent patient died 3 days postoperatively due to hyperperfusion syndrome. Long-term follow-up in two stent patients showed no restenosis at 18 and 48 months, respectively. The 11 balloon angioplasty patients likewise have not demonstrated restenosis. CONCLUSIONS: Balloon angioplasty alone appears too risky for treating recurrent carotid disease. Stents may offer a safer alternative, particularly when implanted primarily.     

Angioplasty after intra-arterial thrombolysis for acute occlusion of intracranial arteries

BACKGROUND and PURPOSE: The purpose of this study was to report our experience with percutaneous transluminal angioplasty (PTA) of intracranial arteries in acute stroke patients who were resistant to intra-arterial thrombolysis alone. METHODS: PTA was performed within 6 hours from symptom onset in 13 acute stroke patients in whom no hypodensity areas were observed on initial CT. PTA was classified into 3 categories: immediate (3 patients), delayed (3 patients), and rescue (7 patients) angioplasty. Treatment results in the PTA group for 9 cases of middle cerebral artery (MCA) occlusion were compared with those in the thrombolysis alone group for 12 cases of thrombotic MCA occlusion. RESULTS: Technical success rates for immediate, delayed, and rescue angioplasty were 100%, 100%, and 71%, respectively, and that of angioplasty for the MCA was 100%. Ten patients (77%) showed improvement in the National Institutes of Health (NIH) stroke score after treatment. Improvement in NIH stroke scores in the PTA group for MCA occlusion was greater than that in the thrombolysis alone group (P<0.01). Nine patients (69%) had an excellent, good, or fair outcome 3 months after treatment. In 9 patients who had follow-up angiography 1 month after treatment, no restenosis or reocclusion was demonstrated. There were no symptomatic complications during or after treatment. CONCLUSIONS: This limited study demonstrates the technical feasibility of angioplasty for intracranial arteries in acute ischemic stroke and suggests that angioplasty may be an effective option for improving the success rate of recanalization and preventing reocclusion of the MCA. The present results encourage us to perform further clinical trials in a larger number of patients to assess the efficacy of this procedure.     

Tooth structure loss apical to preparations for fixed partial dentures when using self-limiting burs

BACKGROUND: Endovascular treatment of cerebral aneurysms is a relatively new method, since only a few animal models and data are available. The present experimental study was performed in order to establish an appropriate aneurysm animal model, to determine the rate of permanent occlusion, and to correlate radiologic and morphologic findings. METHODS: End-to-side anastomoses of both common carotid arteries were performed microsurgically in 53 chinchilla rabbits. Venous pouches were adapted into the newly created bifurcation, resulting in berry-shaped aneurysms comparable to those in humans with regard to size and hemodynamics. Platinum and tungsten coils were used for endovascular embolization. The embolized aneurysms were investigated radiologically and morphologically. RESULTS: Twenty-three carotid bifurcation aneurysms remained for testing endovascular therapeutic approaches. The morphologic examinations of 13 embolized aneurysms revealed in no instance a complete obliteration, even in the three cases that were considered completely embolized according to angiographic criteria. CONCLUSIONS: The present animal model is an optimal tool for endovascular research. Analysis of the results of coil obliteration revealed a considerable discrepancy between radiologic and pathologic findings. The radiologic degree of aneurysm occlusion was overestimated.