PubMed Health⌕ Search

Biomedical subjects

S P Lownie

Publications and source records attributed to S P Lownie.

At least 19 recordsLinked to original sources
PubMed2003

Combined endovascular/neurosurgical therapy of blister-like distal internal carotid aneurysms.

OBJECTIVE: To describe a novel therapeutic strategy for the treatment of "blister-like" aneurysms of the distal internal carotid artery (ICA). Direct surgical treatments of these fragile lesions have been associated with generally poor outcomes. METHODS: Two consecutive patients presenting with acute subarachnoid hemorrhage from "blister-like" aneurysms were treated with preliminary balloon occlusion of the ICA, followed by surgical trapping of the ICA beyond the aneurysm. RESULTS: The treatment resulted in complete thrombosis of both aneurysms with no clinical complications. CONCLUSION: This combined endovascular-neurosurgical approach offers a controlled, safer alternative to primary surgical therapy of "blister-like" aneurysms.

Adult↗
PubMed2002

Carotid stenting without angioplasty.

BACKGROUND: Carotid angioplasty and stenting is gaining popularity as an alternative to carotid endarterectomy for the treatment of carotid bifurcation stenosis. The major concern with the procedure is the risk of embolic stroke which may be initiated by balloon angioplasty of friable atherosclerotic plaque. Elimination of angioplasty may result in a lower incidence of embolic complications. METHOD: We describe a case in which a self-expanding stent alone, without balloon angioplasty, was used to successfully dilate an atherosclerotic stenosis of the carotid bifurcation. RESULTS: A moderate increase in vessel diameter, from 75% to 50%, was immediately observed after stent placement alone. No embolic complications were observed and follow-up plain film and ultrasound examinations showed progressive stent enlargement with excellent anatomic and hemodynamic results. CONCLUSIONS: In this case of severe carotid stenosis, the use of a self-expanding stent alone, without balloon angioplasty, resulted in excellent anatomic and hemodynamic improvement.

Aged↗
PubMed2001

Monitoring cerebral perfusion after subarachnoid hemorrhage using CT.

The aim of this prospective study was to assess the feasibility and diagnostic relevance of repetitive dynamic (contrast-enhanced) CT measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) in the first 3 weeks after aneurysmal subarachnoid hemorrhage (SAH). In 15 patients with SAH, 59 dynamic CT studies including 944 regions of interest (ROI) were analyzed. The results were correlated with the clinical course and time after the event and the occurrence of vasospasm. Values for the entire series were 33.8+/-19.3 ml/100 g/min (CBF), 3.3+/-1.3 ml/100 g (CBV), and 7.3+/-3.9 s (MTT). Significant differences in CBF and CBV were found between ROI in grey and white matter, with time after the event, between patients with significant and absent or minor vasospasm, and between patients with and without a presumed vasospasm-related infarct.

Cerebrovascular Circulation↗
PubMed2001

June 2001: 61 year old woman with confusion and obtundation.

The June COM. A 61 year old female presents with a three week history of increasing confusion, lethargy and headache. A neurological exam revealed disorientation, mild expressive aphasia, bilateral papilledema, and a right pronator drift. She had a craniotomy and resection of tumor. The tumor histologically was consistent with a solitary fibrous tumor displaying malignant features of hypercellularity, marked nuclear atypia, high mitotic activity, and a high proliferation index. This case is unique as the first malignant variant of solitary fibrous tumor to be reported intracranially.

Antigens, CD34↗
PubMed2000

Carotid angioplasty and stenting: current status.

Carotid angioplasty and stenting has recently emerged as a popular alternative to endarterectomy for the treatment of carotid atherosclerosis. Carotid endarterectomy has been scientifically validated, but many believe carotid angioplasty and stenting to be a less invasive, less expensive and equally safe and effective method of treatment. The evidence for and against the use of each procedure will be discussed.

Angioplasty↗
PubMed2000

Clinical presentation and management of giant anterior communicating artery region aneurysms.

OBJECT: The authors reviewed their 20-year experience with giant anterior communicating artery aneurysms to correlate aneurysm size with clinical presentation and to analyze treatment methods. METHODS: In 18 patients, visual and cognitive impairment were quantitated and clinical outcome was categorized according to the Rankin scale. Statistical analysis was performed using Fisher's exact test. CONCLUSIONS: At least 3.5 cm of aneurysm mass effect was required to produce dementia in the patient (p = 0.0004). Dementia was usually caused by direct brain compression by the aneurysm rather than by hydrocephalus. Optic apparatus compression occurred with smaller aneurysms (2.7-3.2 cm) when they pointed inferiorly. Aneurysm neck clipping was possible in half of the cases. Special techniques, including temporary clipping, evacuation of intraluminal thrombus, tandem and/or fenestrated clipping, and clip reconstruction were often required. Occlusion of or injury to the anterior cerebral artery (ACA) was the main cause of poor outcome or death. Proximal ACA occlusion, even of dominant A1 segments with small or no contralateral A1 artery, was an effective treatment alternative and was well tolerated as a result of excellent leptomeningeal collateral circulation.

Adult↗
PubMed2000

Endovascular therapy of a large vertebral artery aneurysm using stent and coils.

BACKGROUND: Endovascular therapy is becoming an increasingly popular treatment for cerebral aneurysms. Total angiographic occlusion of small-necked aneurysms (<4 mm) can be obtained in a high percentage of cases. The endovascular treatment of wide-necked or fusiform aneurysms remains a challenge with complete angiographic occlusion reported in <15% of cases. CASE REPORT: We describe the combined use of a flexible coronary stent and platinum coils to treat a wide-necked aneurysm of the distal left vertebral artery, in a patient with Grade IV subarachnoid hemorrhage. RESULTS: The procedure was technically successful as the parent artery was protected by the stent while coils were deposited in the aneurysm lumen. Although angiographic aneurysm occlusion was incomplete, the dome was packed with coils. No further hemorrhage has occurred. CONCLUSION: Combined endovascular stent and coil therapy is a promising technique for the treatment of wide-necked cerebral aneurysms.

Cerebral Angiography↗
PubMed2000

Giant cavernous carotid aneurysms: clinical presentation in fifty-seven cases.

OBJECTIVES: To review the presenting symptoms and ophthalmic findings of 57 patients with cavernous carotid aneurysms of giant size (> or = 2.5-cm diameter). MATERIALS AND METHODS: Hospital charts of 57 patients with giant cavernous carotid aneurysms who presented to University Hospital in London, Ontario, Canada between 1961 and 1993 were reviewed. All patients were proven by cerebral angiography to have unruptured giant cavernous carotid aneurysms. RESULTS: Forty-six patients (81%) were women (mean age, 54 years). The most common presenting symptoms were diplopia (89%), retroorbital pain (61%), headache (19%), diminished or blurred vision (14%), and photophobia (4%). The most common clinical sign was partial or complete ophthalmoplegia (93%). Trigeminal nerve involvement was found in 37% of patients. Other clinical signs included ptosis, decreased visual acuity, proptosis, and visual field defects. CONCLUSIONS: This study characterizes a large group of patients with giant cavernous carotid aneurysms seen over a 30-year period at a single institution. As in previous studies, diplopia and retroorbital pain were the most common symptoms. The high incidence of ophthalmoplegia observed in this study may be explained by a greater compressive and/or ischemic effect of giant aneurysms compared with their smaller counterparts.

Adolescent↗
PubMed1998

Conservative treatment of acute spontaneous spinal epidural hematoma.

BACKGROUND: In cases of acute spontaneous epidural hematoma producing neurological deficits, emergency surgical evacuation is the standard treatment. METHODS: Such a case is presented in which complete resolution of neurological deficits occurred without surgical intervention. RESULTS: This is the fifth reported case of complete recovery in a patient managed conservatively. In most reports, significant and sustained neurological recovery had occurred with 12 hours of impairment of walking. CONCLUSION: In cases of acute spontaneous spiral epidural hematoma in which neurological deterioration is followed by early and sustained recovery, non-operative therapy may be considered.

Acute Disease↗
PubMed1998

Case of the month: April 1998--30 year old male with perineal numbness.

A 30-year-old male presented with a 2 year progressive course of bowel and bladder dysfunction, mild leg weakness and sensory abnormalities in sacral dermatomes. MRI showed an intra-axial conus medullaris lesion which was excised and identified as a ganglioglioma. The case presents the typical clinical course and histopathology of this unusual lesion which carries a favorable prognosis after gross total removal. Preoperative neurological function in such patients is highly predictive of post-operative outcome.

Adult↗
PubMed1998

Thromboembolic events associated with the treatment of cerebral aneurysms with Guglielmi detachable coils.

BACKGROUND AND PURPOSE: The purpose of this study was to document the prevalence, radiologic appearance, and treatment of thromboembolic events related to GDC embolization of cerebral aneurysms. METHODS: The clinical and radiologic records of all patients undergoing GDC treatment of intracranial aneurysms at our institution were reviewed. All cases in which unexpected complications occurred were selected. Those complications related to presumed thromboembolic events were analyzed. RESULTS: Of 59 patients (60 aneurysms) treated with GDCs, 17 (28%) experienced thromboembolic events. Seven patients had transient ischemic attacks and 10 had strokes. In 10 patients, the deficits occurred during or immediately after the procedure; in the rest, the complications were delayed. In six patients, all radiologic investigations were negative for infarction and in seven patients, CT scans showed new ischemic lesions. In four patients, MR imaging alone showed infarcts, and in four of nine patients who underwent subsequent angiography, acute ischemic findings were demonstrated. Eight patients were treated with volume expansion, eight with full heparinization, and one patient underwent intraarterial thrombolysis. Clinical outcome was excellent or good in 14 of 17 patients, with only three patients (5%) incurring permanent neurologic deficits. CONCLUSION: Thromboembolic events related to GDC treatment may be more common than has been reported in the literature. In our experience, this rate was 28%, with persisting deficits in 5%. These events can occur after uncomplicated procedures and may be unaccompanied by radiologic findings. Clinical outcome is usually favorable.

Adult↗
PubMed1997

Intracranial dural arteriovenous fistulae with pial venous drainage: combined endovascular-neurosurgical therapy.

BACKGROUND: Intracranial dural arteriovenous fistula with pial venous drainage may present with hemorrhage or focal neurologic deficit and may be difficult to treat. We wish to summarize the therapeutic approaches to these potentially dangerous lesions and to demonstrate how endovascular and neurosurgical therapies may have complimentary roles in their management. METHODS: The clinical and radiological records of all patients who presented to our institution with intracranial dural arteriovenous fistula over the last 5 years were reviewed. In those cases demonstrating pial venous drainage, details of presentation, imaging features, endovascular and surgical therapy and outcome were analyzed. RESULTS: We identified 13 patients with these lesions, 7 of whom presented with intracranial hemorrhage. Six patients were treated with embolization alone. Angiographic cure was achieved in 4. There was one complication in this group, a subarachnoid hemorrhage following glue injection. Four patients were treated with embolization followed by surgical occlusion of the pial venous drainage. Angiographic cure was achieved in all 4. There was one complication in this group, a facial nerve palsy following glue injection. Three patients were treated by surgery alone, with no complications and complete cure in all. CONCLUSION: Endovascular therapy of intracranial dural arteriovenous fistula may be curative but is often complex and carries definite risks. Neurosurgical ligation of pial draining veins, with pre-operative embolization when safe, may be a relatively more controlled method to achieve complete cure.

Adult↗
PubMed1995

Anesthesia for interventional neuroradiology.

STUDY OBJECTIVE: To review the anesthetic management and the occurrence and treatment of complications in patients undergoing interventional neuroradiologic procedures for the treatment of intracranial vascular lesions. DESIGN: Retrospective chart review of 115 charts from 1988 to 1992. SETTING: University hospital. MEASUREMENTS AND MAIN RESULTS: Charts were reviewed for information regarding the anesthetic management, monitoring techniques, complications, treatment of complications, and clinical outcome. Group 1 patients (n = 92) were managed by an anesthesiologist; 8 received general anesthesia and 84 had conscious sedation. Group 2 patients (n = 70) were cared for by a neuroradiologist; 37 received intravenous analgesia (fentanyl) and 33 received no sedation other than premedication (benzodiazepine). No episodes of anesthetic or drug-related complications were documented. Complications directly related to technical aspects of the procedure were documented in 33 (20%) cases, 19 (21%) in Group 1 and 14 (20%) in Group 2. These complications consisted of ischemia (n = 14), hemorrhage (n = 9), catheter misplacement (n = 8), and pulmonary embolism (n = 2). Four patients, two in each group, required urgent assessment by an anesthesiologist. CONCLUSIONS: There was no difference in the incidence of complications between the two groups. As the use of interventional neuroradiology increases, the anesthesiologist will be more involved in the elective or emergency treatment of these patients.

Adult↗