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Biomedical subjects

R T Higashida

Publications and source records attributed to R T Higashida.

At least 55 records · Page 3Linked to original sources
PubMed1999

Treatment of posterior circulation ischemia with extracranial percutaneous balloon angioplasty and stent placement.

BACKGROUND AND PURPOSE: Vertebrobasilar territory ischemia (VBI) leads to disabling neurological symptoms and poses a risk for stroke by an embolic or flow-related mechanism. We present our clinical experience in the endovascular treatment of patients with symptomatic VBI from severe atherosclerosis or dissection of the vertebral and subclavian arteries that was unresponsive to medical therapy. METHODS: Twenty-one patients (9 female, 12 male) with a mean age of 65.7 years (range 47 to 81 years) underwent treatment with percutaneous endovascular balloon angioplasty and stent placement. Sixteen patients (76.2%) had evidence of contralateral involvement, and 9 (42.8%) demonstrated severe anterior-circulation atherosclerosis. Nine patients had a previous infarct in the occipital lobe, cerebellum, or pons before treatment. Follow-up was available for all patients. RESULTS: Balloon angioplasty with intravascular stent placement was performed in 13 vertebral artery lesions (10 at the origin, 3 in the cervical segment) and in 8 subclavian lesions. The prestenting stenosis was 75% (50% to 100%) and was reduced to 4.5% (0% to 20%) after stenting. Six of the patients with proximal subclavian stenosis demonstrated angiographic evidence of subclavian steal, which resolved in all cases after treatment. All patients showed improvement in symptoms after the procedure except for 1 who developed a hemispheric stroke after thrombotic occlusion of an untreated cavernous carotid artery stenosis (rate of major stroke and mortality=4.8%). One patient (4.8%) had a periprocedural transient ischemic attack (TIA), and none had minor stroke. At long-term follow-up (mean=20.7+/-3.6 months) of the surviving 20 patients, 12 (57.1%) remained symptom-free, 4 (19%) had at most 1 TIA over a 3-month period, 2 (9.5%) had at most 1 TIA per month, and 2 (9.5%) had persistent symptoms. There were no clinically evident infarcts during the follow-up period. CONCLUSIONS: Endovascular treatment using balloon angioplasty with intravascular stent placement for symptomatic stenotic lesions resulting in VBI that is unresponsive to medical therapy appears to be of benefit in this high-risk subset of patients with poor collateral flow.

Aged↗
PubMed1999

Acquired pial arteriovenous fistula following cerebral vein thrombosis.

BACKGROUND: We report a unique case of an acquired pial arteriovenous fistula occurring after an asymptomatic thrombosis of a superficial cerebral vein. CASE DESCRIPTION: A cerebral angiogram performed in a 51-year-old man with subarachnoid hemorrhage revealed a 10-mm ruptured anterior communicating artery aneurysm and a thrombosed left superficial middle cerebral vein. Coil embolization of the anterior communicating aneurysm was performed. Follow-up angiography 18 months later revealed a new, asymptomatic, pial arteriovenous fistula between the previously thrombosed left superficial middle cerebral vein and a small sylvian branch of the left middle cerebral artery. CONCLUSIONS: This case provides evidence that pial arteriovenous fistulas may develop as acquired lesions and furthermore may rarely follow cerebral vein thrombosis. Several cases of dural arteriovenous fistulas, as well as a single case of a mixed pial-dural arteriovenous fistula, occurring after dural sinus thrombosis have been reported previously. However, to our knowledge, this is the first report of an acquired pial arteriovenous fistula following a cerebral vein thrombosis.

Aneurysm, Ruptured↗
PubMed1999

Clinical use of stents for carotid artery disease.

Over the last 5 years, the clinical use of intravascular stents for treatment of carotid artery pathology has become more prevalent and the spectrum of potential indications has widened. Endovascular stenting is providing an alternative to surgical endarterectomy for treatment of cervical carotid artery atherosclerotic disease. This has prompted a North American, randomized, controlled clinical trial directly comparing these two therapies. In this article we review the major surgical endarterectomy trials that currently provide the scientific rationale for revascularization of carotid artery occlusive disease, critically evaluate the evidence supporting the application of endovascular stenting procedures for the treatment of occlusive and nonocclusive disease of the extracranial and intracranial carotid artery, consider the current clinical indications for use of stents in the carotid artery, and discuss current equipment, technique, and potential procedure-related complications.

Angioplasty, Balloon↗
PubMed1999

Intraventricular contrast medium leakage during ethanol embolization of an arteriovenous malformation.

We report the unusual phenomenon of abrupt intraventricular contrast medium leakage from the choroid plexus occurring during ethanol embolization of a periventricular arteriovenous malformation. There was no evidence of any associated intraventricular hemorrhage to suggest that leakage arose from a vessel perforation, as was first suspected. Intraventricular contrast medium leakage has been reported previously in the setting of ependymitis, and it is likely that similar pathogenetic mechanisms apply in this case. To our knowledge, this is the first reported case of intraventricular contrast medium leakage occurring during an embolization procedure.

Brain↗
PubMed1998

The effect of oestrogen on the development of arteriovenous fistulae induced by venous hypertension in rats.

PURPOSE: Dural arteriovenous fistulae (AVF) represent abnormal communication between the meningeal arteries and the dural sinuses. Clinically, this condition appears more frequently in post-menopausal and pregnant women than in the general population. Oestrogen is believed to play an important role in the development of dural AVF; however, its exact role has not been clearly defined. We have previously reported that by surgically creating a carotid-jugular shunt in male rats, which then induces venous hypertension, spontaneous arteriovenous fistulae can result. To examine the specific role that oestrogen may have in the development of AVF induced by venous hypertension, we performed the following experimental procedure. MATERIALS AND METHODS: Ninety-four Sprague-Dawley female rats (250-300 grams in weight) were randomly assigned to four different groups. Group 1 (n = 20): control (bilateral ovariectomy only). Group 2 (n = 19): bilateral ovariectomy and implantation of the oestrogen pellet (17-beta oestradiol 0.75 mg/pellet, 60 days release). Group 3 (n = 17): bilateral ovariectomy and venous hypertension (left carotid-jugular shunt with proximal jugular vein occlusion). Group 4 (n = 38): bilateral ovariectomy and oestrogen pellet implantation and venous hypertension. All of the groups were examined by angiography 60 days after treatment. In Groups 1 and 2, bilateral common carotid angiography was performed via a transfemoral route. In Groups 3 and 4, angiography was done after surgical ligation of the carotid-jugular shunt to examine for any newly developed AVF. RESULTS: No newly developed AVF were found in either Groups 1, 2, or 3. In Group 4, 2 rats (5.3%) developed newly formed AVF which occurred in the nose and neck. Our previous study demonstrated that AVF appeared in 3 of 22 (13.6%) venous hypertensive male rats. Therefore, no statistical difference in the appearance rate of newly formed AVF was found among groups 1, 2, 3 or 4 and between our previously reported group of male venous hypertensive rats. CONCLUSION: In this experimental study, ovariectomy with or without oestrogen did not affect the development of spontaneous AVF induced by venous hypertension.

Animals↗
PubMed1998

PROACT: a phase II randomized trial of recombinant pro-urokinase by direct arterial delivery in acute middle cerebral artery stroke. PROACT Investigators. Prolyse in Acute Cerebral Thromboembolism.

BACKGROUND AND PURPOSE: To test the safety and recanalization efficacy of intra-arterial local delivery of plasminogen activators in acute ischemic stroke, a randomized trial of recombinant pro-urokinase (rpro-UK) versus placebo was undertaken in patients with angiographically documented proximal middle cerebral artery occlusion. METHODS: After exclusion of intracranial hemorrhage by CT scan, patients with abrupt onset of symptoms of focal ischemia likely to receive treatment within 6 hours who satisfied all clinical eligibility criteria underwent carotid angiography. Patients displaying Thrombolysis in Acute Myocardial Infarction grade 0 or 1 occlusion of the M1 or M2 middle cerebral artery were randomized 2:1 to receive rpro-UK (6 mg) or placebo over 120 minutes into the proximal thrombus face. All patients received intravenous heparin. Recanalization efficacy was assessed at the end of the 2-hour infusion, and intracerebral hemorrhage causing neurological deterioration was assessed at 24 hours. RESULTS: Of 105 patients who underwent angiography, 59 were excluded from randomization. Among the 46 patients randomized, 40 were treated with rpro-UK (n=26) or placebo (n=14) a median of 5.5 hours from symptom onset. Recanalization was significantly associated with rpro-UK (2P=.017). Hemorrhagic transformation causing neurological deterioration within 24 hours of treatment occurred in 15.4% of the rpro-UK-treated patients and 7.1% of the placebo-treated patients (2P=.64). Both recanalization and hemorrhage frequencies were influenced by heparin dose. CONCLUSIONS: Intra-arterial local rpro-UK infusion was associated with superior recanalization in acute thrombotic/ thromboembolic stroke compared with placebo. In this regimen, heparin dose influenced hemorrhage frequency and recanalization. Although symptomatic hemorrhage remains a concern, this study suggests that recanalization is enhanced with rpro-UK and heparin.

Acute Disease↗
PubMed1998

Endovascular treatment of mural-type vein of Galen malformations.

OBJECT: In this study the authors report on the results of endovascular treatment for mural-type vein of Galen malformations (VGMs) in a group of infants. METHODS: Eight children (six infants and two neonates) who suffered from symptoms caused by a mural-type VGM were treated by means of endovascular therapy. Their age at the time of treatment ranged from 13 days to 19 months (mean 7.6 months). Two neonates and three infants who presented with hydrocephalus and increased head circumference, one of whom was stabilized with a shunt, underwent elective closure of the malformations 3, 4, 6, 6, and 13 months later, respectively. Two patients presented with hemorrhage; one had an intraventricular hemorrhage (IVH) on the 1st day of life and one, a 5-month-old infant, suffered a large parenchymal hemorrhage and an IVH; both patients were immediately cured by means of endovascular techniques. One child presented with a seizure and cortical venous drainage that were treated immediately. Eleven separate treatment sessions were conducted; eight via transarterial femoral access and the remaining three via a transvenous approach. Two patients were treated by using transfemoral transvenous embolization with fibered coils, and one patient required a transtorcular transvenous approach to permit complete closure of the fistula with electrolytically detachable coils. The embolic devices used included silk suture emboli (three patients), electrolytically detachable coils (three patients), and fibered platinum coils (seven patients). In seven patients, complete closure was demonstrated on postembolization arteriographic studies. The eighth patient had stagnant flow in a giant 6-cm varix treated with arterial and venous coils but has not yet undergone follow-up studies. Late follow-up arteriography was performed in four patients at times ranging from 11 to 24 months postprocedure. In one patient, thrombosis of the malformation and shrinkage of the varix were confirmed on follow-up computerized tomography scanning. The remaining three patients have not yet undergone follow-up angiographic examination. Two asymptomatic complications occurred, including separation of the distal catheter, which was removed with a snare device, and a single platinum coil that embolized to the lung, producing no symptoms in 101 months of clinical follow up. The follow-up period ranged from 3 to 105 months, with a mean of 52 months. CONCLUSIONS: Endovascular therapy is the treatment of choice for mural-type VGMs and offers a high rate of cure with low morbidity.

Arteriovenous Fistula↗
PubMed1998

Causes and management of aneurysmal hemorrhage occurring during embolization with Guglielmi detachable coils.

OBJECT: The purpose of this review is to describe the incidence, causes, management, and outcome of aneurysmal hemorrhage that occurred in patients during endovascular treatment with the Guglielmi detachable coil (GDC) system. METHODS: At the authors' institution between September 1991 and August 1995, more than 200 patients were treated using GDCs for intracranial aneurysms. The first 200 patients treated in this fashion were reviewed and all who experienced new subarachnoid hemorrhage (SAH) during the procedure were identified. Angiographic studies were also reviewed and patients were contacted for longer-term follow up when possible. Four patients who experienced intraprocedural SAH were identified. The causes of hemorrhage were believed to be perforation of the aneurysm by the guidewire in one patient, perforation by the microcatheter in a second, and perforation by the delivery wire in a third. The fourth patient had a hemorrhage during injection of contrast material for control angiographic studies after placement of the final coil. One patient died, but the other three experienced no neurological symptoms or recovered without acquiring additional deficits. Overall a procedural hemorrhage rate of 2% was seen, with permanent morbidity and mortality rates of 0% and 0.5%, respectively. CONCLUSIONS: Although SAH during endovascular treatment of intracranial aneurysms remains a significant risk, its incidence is low and a majority of patients can survive without serious sequelae.

Adult↗
PubMed1998

Diagnosis and treatment of dural arteriovenous fistulas.

Dural arteriovenous fistulas (DAVFs) are abnormal vascular connections located within the dura mater which are thought to be promoted by venous hypertension and venous sinus thrombosis. The symptoms associated with DAVFs depend on the direction and adequacy of venous drainage pathways, the amount of arteriovenous shunting and specific location of the fistula. Our experience over a period of eight years with 268 patients suffering from cranial DAVFs in the transverse, sigmoid, superior sagittal, ethmoidal, inferior and superior petrosal, cavernous, and marginal sinuses are presented. The clinical presentation, radiographic evaluation, and treatment modalities for DAVFs in each of these locations are summarized.

Angiography↗
PubMed1998

Endovascular treatment of pseudoaneurysms with electrolytically detachable coils.

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.

Adult↗
PubMed1997

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.

Acute Disease↗
PubMed1997

Dural arteriovenous fistulas of the marginal sinus.

PURPOSE: To investigate the clinical presentation, angiographic findings, endovascular management and clinical outcome in dural arteriovenous fistulas (DAVFs) of the marginal sinus. METHODS: Fourteen patients with DAVFs of the marginal sinus were identified from angiographic studies and medical records of all patients treated for DAVFs at our institution between July 1990 and August 1995. The endovascular treatment and clinical outcomes of these patients are reported. RESULTS: Eleven patients had pulse-synchronous bruit, two had intracranial hemorrhage, and one had ataxia. Thirteen patients were cured with endovascular techniques alone and one was cured by a combination of preoperative embolization followed by surgical obliteration of the fistula. The sole complication of treatment was a partial left hypoglossal nerve palsy, which resolved spontaneously. CONCLUSION: DAVFs of the marginal sinuses are potentially life-threatening lesions that can be treated with endovascular techniques for a high rate of cure and a low rate of morbidity.

Adult↗