Search PubMed⌕ Search

Biomedical subjects

S L Barnwell

Publications and source records attributed to S L Barnwell.

At least 37 records · Page 2Linked to original sources
PubMed1996

Intracranial intraarterial thrombolysis facilitated by microcatheter navigation through an occluded cervical internal carotid artery.

This report covers a series of four patients with acute cervical carotid occlusion and profound neurological deficits who were treated with intracranial intraarterial thrombolysis. All of the patients presented with arm plegia with variable leg involvement and two of them had global aphasia. Angiography identified occlusion of the proximal internal carotid artery (ICA) in each case and intracranial thromboembolus of the supraclinoid ICA and/or its branches. Catheter navigation through the occluded ICA segment was straightforward in three patients and somewhat difficult in one patient with an 80% ICA stenosis. Intraarterial urokinase infusion along with mechanical clot disruption was performed at the clot site in the middle cerebral artery, supraclinoid ICA, and/or anterior cerebral artery. All patients had recanalization of the treated artery after urokinase infusion. Antegrade flow through the ICA was reestablished in two patients, and good collateral filling across the anterior communicating artery was established in the other two. All patients had major pretreatment deficits (mean National Institutes of Health (NIH) Stroke Score 24 +/-4) with significant improvement noted at 3 months posttreatment (NIH Stroke Score 7 +/-6;p=0.03). Two patients made a dramatic early recovery. Postprocedure computerized tomography revealed no abnormality in one and asymptomatic basal ganglia high density from repeated local contrast injections in two patients. On the basis of their findings in this small study group the authors suggest that catheter navigation through a presumably occluded carotid artery is feasible and possibly effective in thrombolytic therapy of intracranial thrombolysis. Further study with clinical trials is necessary to determine the safety and efficacy of this technique.

Adult↗
PubMed1995

Interventional neurovascular techniques in the treatment of stroke--state-of-the-art therapy.

Interventional neurovascular techniques for the treatment of patients presenting with symptoms of acute or impending stroke, are now being utilized with increasing frequency in three major areas. (i) For patients presenting with cerebrovascular ischaemic symptoms due to haemodynamically significant stenosis from atherosclerosis, vasculitis, intimal hyperplasia, and dissection, cerebral percutaneous transluminal angioplasty has been shown to be beneficial for both extracranial and intracranial disease. (ii) Patients with acute, embolic occlusion of the internal carotid, middle cerebral, distal vertebral, and basilar arteries have been successfully treated by placement of microcatheters directly into the thrombus with successful thrombolysis, recanalization, and reperfusion to the distal ischemic brain. (iii) Acute arterial vasospasm secondary to subarachnoid haemorrhage is now being managed by balloon angioplasty in those instances where conventional medical therapy has failed. These techniques are altering our current management and broadening the therapeutic alternatives for patients who present with acute cerebrovascular insufficiency and stroke in evolution. As wider experience is gained in these techniques, the clinical indications for their use will also broaden.

Adolescent↗
PubMed1995

Safety and efficacy of percutaneous transluminal angioplasty for intracranial atherosclerotic stenosis.

BACKGROUND AND PURPOSE: Percutaneous transluminal angioplasty (PCTA) is increasingly used to treat extracerebral arterial stenosis. The present study evaluates the safety and efficacy of PCTA treatment of symptomatic intracranial atherosclerotic stenosis. METHODS: A series of 22 vessels in 17 patients were treated with PCTA. All patients had recurrent neurological symptoms referable to the stenotic vessel despite optimal medical therapy. Critical (> 70%) arterial stenosis was confirmed by angiogram, and angioplasty was performed with a 3.0- to 3.5-mm Stealth balloon. RESULTS: The average preangioplasty stenosis (North American Symptomatic Carotid Endarterectomy Trial criteria) was 72 +/- 8% (mean +/- SD), with a significant improvement seen after angioplasty; the best angiographic stenosis (after healing of intimal injury, if any) was 43 +/- 24% (P < .001). Overall PCTA was successful in 82% of the vessels. There were two strokes during angioplasty for a 30-day morbidity rate of 9.1% per treated vessel and 11.7% per case. The other 15 patients were clinically evaluated at 3 and 6 months; all cases were without further events. Restenosis was evaluated in 8 patients (12 vessels) with an angiogram at 6 months showing further improvement compared with the initial post-PCTA stenosis (51 +/- 10% versus 37 +/- 21% [P = .05]). CONCLUSIONS: PCTA may be a beneficial therapy in selected cases of symptomatic intracranial atherosclerotic stenosis. Further study using a randomized trial is needed.

Aged↗
PubMed1995

Middle meningeal artery aneurysm associated with meningioma: case report.

Middle meningeal artery aneurysms are rare. Fewer than 10 true aneurysms and 30 posttraumatic aneurysms on meningeal vessels have been reported. True meningeal aneurysms are associated with tumors, Paget's disease, arteriovenous malformations, and trauma. Potential morbidity is demonstrated with hemorrhage from true aneurysms as well as from pseudoaneurysms of the meningeal vessels. We have described a meningeal artery aneurysm of the vascular pedicle of a convexity meningioma and reviewed the literature.

Aged↗
PubMed1994

Thrombolytic therapy in acute stroke.

PURPOSE: To report the safety and efficacy of local, direct, intra-arterial and intravenous fibrinolysis treatment in selected cases of clinically symptomatic patients with acute occlusion of the intracranial cerebral arteries and dural sinuses. METHODS: Patients with acute progressive neurological deterioration, in spite of systemic anticoagulation and/or antiplatelet medications, presenting with occlusion of a major intracranial cerebral artery or dural sinus were tested. From a transfemoral approach through a guiding catheter, a 2.5F microcatheter was guided directly into the intracranial cerebral circulation and embedded within the clot. Infusion of urokinase was then performed directly into the thrombus until lysis was attained. RESULTS: In 36 total patients, 27 cases were treated for an acute arterial occlusion in 45 vascular territories. Clinically, there was neurological improvement in 18 (66.7%) cases. Complications directly related to therapy included symptomatic intracranial hemorrhage in three cases (11.1%), which included 1 case (3.7%) of vessel perforation. In 8 (29.6%) patients, there was no evidence of clinical improvement, and in long-term follow-up there were 9 (33.3%) patient deaths. Nine patients were treated for an intracerebral dural sinus thrombosis in ten vascular territories by local urokinase infusion. In 7 (77.8%) cases, there was angiographic evidence of clot lysis and clinical improvement of the patient's neurological condition. Minor complications including infection and noncerebral sites of bleeding occurred in 3 (33.3%) patients, requiring adjustment in urokinase infusion therapy. CONCLUSION: Local, direct intra-arterial or intravenous infusion of thrombolytic drugs for treatment of stroke patients may improve overall patient morbidity and mortality related to acute thromboembolic disease in the central nervous system. Further clinical studies are warranted to evaluate this form of therapy.

Acute Disease↗
PubMed1994

The efficacy of endosaccular aneurysm occlusion in alleviating neurological deficits produced by mass effect.

Endovascular obliteration of intracranial aneurysms with preservation of the parent artery (endosaccular occlusion) has been advocated for patients who fail or are excluded from surgical clipping and cannot undergo Hunterian ligation therapy. To clarify the effect that endosaccular occlusion has on the presenting neurological signs, 26 patients with aneurysms and symptoms related to mass effect who underwent this therapy were followed for a mean of 60 months. Only patients with objective neurological deficits who had not suffered a hemorrhage were included in this series. Response to therapy was classified into one of three groups: "resolved," if the patient had complete resolution of presenting signs; "improved," if significant and sustained improvement was recorded in the neurological examinations, and "unchanged," if no change was observed. Thirteen patients (50%) were classified as resolved, 11 (42.3%) as improved, and two (7.7%) as unchanged. A comparison of patients classified as resolved with those who were improved revealed that the former group had less wall calcification (30% vs. 60%) and a shorter duration of symptoms. Patients with neurological sign resolution (62%) were more likely to have totally occluded aneurysms on late follow-up arteriograms than those who had improvement (28%) or were unchanged (0%). This study suggests that endosaccular embolization therapy can improve or alleviate presenting neurological signs unrelated to hemorrhage or distal embolization in the majority of cases.

Adolescent↗
PubMed1994

Safety and efficacy of delayed intraarterial urokinase therapy with mechanical clot disruption for thromboembolic stroke.

PURPOSE: To evaluate safety and efficacy of delayed intraarterial urokinase therapy with mechanical disruption of clot to treat thromboembolic stroke. METHODS: Thirteen patients with cerebral thrombolic disease (10 carotid territory, 3 basilar territory) were treated with catheter-directed intraarterial urokinase therapy with mechanical disruption of the clots. All patients were excluded from a 6-hour multicenter thrombolytic trial by either time, recent surgery, age, seizure, or myocardial infarction. Time elapsed before treatment ranged from 3.5 to 48 hours (12 +/- 13 hours), with 200,000 to 900,000 U of urokinase used. RESULTS: Ten patients had successful vessel recanalization, confirmed by repeat angiography. Cases with distal branch vessel occlusions were less likely to recanalize. Asymptomatic hemorrhagic conversion occurred in 2 patients on repeat scans. Both acute neurologic and functional outcomes were assessed with significant improvement occurring in 9 (69%) of 13 patients at 48 hours (greater than four-point change on the National Institutes of Health scale) and in 100% of 3-month survivors. All patients who improved had normal initial CT scans. CONCLUSIONS: Intraarterial cerebral thrombolysis with mechanical disruption of clot seems to be a useful therapy in selected stroke cases even after 6 hours.

Adolescent↗
PubMed1994

Treatment of dural sinus thrombosis by urokinase infusion.

PURPOSE: To gain a preliminary understanding of the role of thrombolytic therapy for the thrombosed dural sinus, we retrospectively reviewed our initial experience. METHODS: Seven patients, ages 25 to 71, who presented with symptomatic dural sinus thrombosis and who failed a trial of medical therapy were treated with direct infusion of urokinase into the thrombosed sinus. Patients received urokinase doses ranging from 20,000 to 150,000 U/h with a mean infusion time of 163 hours (range 88 to 244 hours). RESULTS: Patency of the affected dural sinus was achieved with antegrade flow in all patients. Six patients either improved neurologically over their prethrombolysis state or were healthy after thrombolysis; one of them required angioplasty. The other patient improved after surgical repair of a residual dural arteriovenous fistula. The only complications were an infected femoral access site which resolved after treatment with antibiotics and hematuria which cleared after discontinuation of anticoagulation. CONCLUSIONS: Thrombolysis of the thrombosed dural sinus shows promise as a safe and efficacious treatment. The results of this study should provide the impetus for further research.

Adult↗
PubMed1994

Endovascular therapy of carotid cavernous fistulas.

The clinical manifestations of carotid cavernous fistulas, regardless of the type, depend on the pattern of venous drainage from the fistula. Venous drainage toward the orbit produces the usual syndrome of proptosis, chemosis, and arterialization of scleral veins. If the venous drainage is toward the brain, the signs and symptoms may not be as apparent, but the risk for catastrophic hemorrhage is much higher. Although many of these lesions may be managed in a conservative fashion, there are indications for urgent treatment to prevent a devastating hemorrhage or loss of vision. Direct carotid cavernous fistulas can usually be managed by transarterial embolization, most commonly with detachable balloons. The transvenous approach is most efficacious for treating indirect carotid cavernous fistulas.

Arteriovenous Fistula↗
PubMed1993

Treatment of giant intradural (perimedullary) arteriovenous fistulas.

Ten patients with giant intradural spinal arteriovenous fistulas (perimedullary Types II and III) were treated with embolization alone (three patients) or in combination with surgery (seven patients). Their ages at the time of treatment ranged from 2 to 40 years, with a mean of 19.5 years. The indications for treatment included progressive myelopathy in five patients, spinal subarachnoid hemorrhage in four, and acute paraplegia in one. Associated conditions included Rendu-Osler-Weber syndrome in two patients, and Cobb's syndrome in two patients. In one patient, the cause of the fistula may have been related to epidural anesthesia traumatizing a low tethered cord. Angiographically, the fistulas were subclassified in three groups: a single-hole fistula supplied by a single feeding medullary artery (three patients); a single-hole fistula supplied by multiple medullary arteries (three patients); and multiple separate fistulas supplied by multiple medullary arteries (four patients). Eight patients were classified as perimedullary Type III and two as perimedullary Type II. Embolic agents were delivered from transarterial routes in 14 procedures and transvenous routes in 2 procedures. A total of 16 embolizations and 8 operations were performed in 10 patients. Seven patients were cured of their fistula (as demonstrated by angiography), two patients had 5% residual filling and are scheduled for future therapy. One refused a follow-up angiographic examination. Complications related to embolization included rupture of the anterior spinal artery by a detachable balloon, resulting in transient worsening of paraplegia with recovery to baseline. Transient worsening of symptoms after surgery was common, but all patients returned to baseline or better. Dramatic improvement was observed in four patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Interventional neuroradiology.

A wide variety of diseases affecting the central nervous system and head and neck can be treated using interventional neuroradiologic techniques. These new treatments have depended on advances in radiologic imaging, catheter technology, and the development of new embolic agents. These procedures may be an adjunct to other therapy, palliative or curative. Diseases for which interventional neuroradiologic techniques have been major advances in treatment include cerebral aneurysms, vasospasm after subarachnoid hemorrhage, cerebral arteriovenous malformations, dural arteriovenous fistulas, dural sinus thrombosis, atherosclerosis, scalp arteriovenous fistulas, carotid-cavernous fistulas, and stroke. This field is rapidly evolving as advances are made in catheter technology and new embolic agents are developed.

Cerebral Angiography↗
PubMed1991

Interventional neurovascular treatment of a giant intracranial aneurysm using platinum microcoils.

A 70-year-old woman presented with symptoms of progressive cerebellar dysfunction due to mass effect from a giant, expanding, posterior fossa aneurysm arising from the distal vertebral artery. The aneurysm contained thrombus and had a broad-based neck. From a transfemoral approach, with the patient under local anesthesia, a 2.2 French microcatheter was guided through the vertebral artery and placed directly into the aneurysm. Six 5 x 15-mm platinum microcoils were deposited into the residual lumen of the aneurysm, resulting in complete thrombosis with obliteration of the aneurysm and preservation of the parent artery. Endovascular coil embolization therapy by interventional neurovascular techniques may provide a therapeutic alternative in the management of surgically difficult symptomatic intracranial aneurysms.

Aged↗
PubMed1991

Direct endovascular thrombolytic therapy for dural sinus thrombosis.

Three patients, ages 51 to 71 years, sought treatment for symptomatic dural sinus thrombosis with occlusion and were treated by direct sinus perfusion with urokinase. All three patients had a dural arteriovenous fistula; one involved the inferior petrosal sinus and two involved the transverse sinus. Clinical findings included papilledema, diminished visual acuity, decreased mentation, and cranial nerve palsies. Diagnosis was made by cerebral arteriography and confirmed by sinus venography. All three patients were treated by a transjugular direct infusion of urokinase. In one patient, a transfemoral venous approach used initially was discontinued because of an infection. The period of continuous infusion for thrombolysis ranged between 4 and 10 days. In two patients, the clinical signs and symptoms improved with angiographic evidence of clot lysis and dural sinus recanalization. Angiography indicated that one patient had a partial resolution of a clot in the torcular herophili and transverse sinus but showed no clinical improvement. These preliminary results suggest that transjugular local infusion of thrombolytic agents can be an effective treatment for symptomatic, thrombosed dural sinuses. This selective lysis avoids thrombolytic effects that could aggravate or produce systemic hemorrhagic complications.

Aged↗
PubMed1991

Intracranial aneurysms: interventional neurovascular treatment with detachable balloons--results in 215 cases.

Patients with complex or surgically difficult intracranial aneurysms are being treated with interventional neurovascular techniques. With neuroleptic anesthesia and a transfemoral femoral approach, a silicone micro-balloon can be flow directed through the intracranial circulation, guided directly into the aneurysm, and detached. The aneurysm is thus eliminated from the circulation, and the parent artery is preserved. For broad-based or ectatic aneurysms, test occlusion followed by permanent occlusion of the aneurysm and parent vessel can be performed. Since 1981, 211 patients with 215 aneurysms, including 177 cases involving the anterior and 38 cases involving the posterior circulation, have been treated with this technique. In 127 cases (59.1%), the parent vessel was occluded; in 88 cases (40.9%), primary occlusion of the aneurysm was achieved with preservation of the parent artery. Therapy-related complications included 21 deaths (9.8%) and 16 strokes (7.4%). Follow-up examinations were performed at 1, 3, and 12 months after treatment, and follow-up ranged from 5 months to 9 years. In patients in whom standard surgical therapy fails or for aneurysms in surgically inaccessible anatomic locations, interventional techniques that make use of detachable balloons may be a useful therapeutic alternative.

Adult↗
PubMed1991

A variant of arteriovenous fistulas within the wall of dural sinuses. Results of combined surgical and endovascular therapy.

Dural arteriovenous (AV) fistulas are thought to be acquired lesions that form in an area of thrombosis within a sinus. If the sinus remains completely thrombosed, venous drainage from these lesions occurs through cortical veins, or, if the sinus is open, venous drainage is usually into the involved sinus. Among 105 patients with dural AV fistulas evaluated over the the past 5 years, seven had a unique type of dural AV fistula in the superior sagittal, transverse, or straight sinus in which only cortical venous drainage occurred despite a patent involved sinus; the fistula was located within the wall of a patent dural sinus, but outflow was not into the involved sinus. This variant of dural AV fistulas puts the patient at serious risk for hemorrhage or neurological dysfunction caused by venous hypertension. Three patients presented with hemorrhage, one with progressive neurological dysfunction, one with seizures, and two with bruit and headaches. A combination of surgical and endovascular techniques was used to close the fistula while preserving flow through the sinus.

Adult↗
PubMed1990

Intracerebral arteriovenous fistulas associated with intraparenchymal varix in childhood: case reports.

This report describes three children, each of whom developed an unusual malformation consisting of one or more intracerebral arteriovenous fistulas and a large intraparenchymal venous varix. Their clinical symptoms were similar to those produced by aneurysms of the vein of Galen: increasing head circumference, seizures, hemorrhage, and developmental delay. We treated each child with endovascular embolization and/or surgery and obtained complete closure of all fistulas without mortality.

Arteriovenous Fistula↗
PubMed1990

Dural arteriovenous fistulas supplied by ethmoidal arteries.

Eight patients with dural arteriovenous fistulas (DAVFs) located on the floor of the anterior cranial fossa and supplied by enlarged ethmoidal branches of the ophthalmic artery are described. Five patients showed the classical symptom of intracerebral hemorrhage (all five had ipsilateral frontal lobe hematomas and one also had an associated a subdural hematoma). Two patients exhibited atypical symptoms of proptosis, chemosis, elevated intraocular pressure, and loss of vision secondary to an ethmoidal DAVF, which drained posteriorly to the cavernous sinus. The eighth patient exhibited proptosis and chemosis secondary to a cavernous sinus DAVF and was incidentally found to have an asymptomatic ethmoidal DAVF. One additional patient had two separate dural fistulas: one located on the cribriform plate and the second located in the posterior fossa. Seven of the eight patients were cured by surgical excision of the fistula site; in the remaining patient spontaneous obliteration followed a surgical procedure for a cavernous DAVF. DAVFs involving the floor of the anterior cranial fossa usually present with hemorrhage, but can present with ocular symptoms or be entirely asymptomatic and are effectively treated by surgical excision of the fistula site.

Aged↗