Biomedical subjects

J G Frazee

Publications and source records attributed to J G Frazee.

At least 19 recordsLinked to original sources

PubMed2001

Surgical and endovascular treatment of spinal dural arteriovenous fistulas: long-term disability assessment and prognostic factors.

OBJECT: The authors assessed clinical outcomes of patients with treated spinal dural arteriovenous fistulas (DAVFs) and investigated prognostic factors. METHODS: Thirty consecutive patients with spinal DAVFs were treated at the authors' institution during the past 15 years: seven underwent surgery; seven underwent surgery after failed embolization: and 16 underwent embolization alone. The outcomes of gait and micturition disability, were analyzed. Follow up averaged 3.4 years (range 1 month-11.8 years). Age, duration of symptoms, pre- and postintervention magnetic resonance (MR) imaging findings, and preintervention disability were correlated with outcome. Seventeen patients (57%) experienced improved gait, 12 (40%) were unchanged, and one (3%) was worse. In 11 patients (37%) micturition function was improved, in 15 (50%) it was unchanged, and in four (13%) it was worse. Gait disability, as measured by the Aminoff-Logue Scale, was significantly improved after treatment, from 3.4+/-1.4 (average +/- standard deviation) to 2.7+/-1.5 (p = 0.007). Mean micturition disability scores decreased, but not significantly, from 1.9+/-1 to 1.6+/-1.1 (p = 0.20). Preintervention gait disability was not associated with improvement except for patients with Aminoff-Logue Scale Grade 4 disability (eight of nine improved; p = 0.024). For patients treated within 13 months of symptom onset, mean micturition disability decreased (p = 0.035). No association was found between clinical improvement and age, a symptom duration less than 30 months, or pre- and postintervention MR imaging-documented spinal cord edema. CONCLUSIONS: Spinal DAVF treatment significantly improved patients' mean gait disability score by almost one grade at last follow up. The mean micturition disability score was not significantly improved, unless treatment was performed within 13 months of symptom onset. Longer and more uniform follow-up study is needed to determine if improved and stabilized clinical outcomes are sustained.

Aged↗

PubMed2001

N-butyl 2-cyanoacrylate embolization of spinal dural arteriovenous fistulae.

BACKGROUND AND PURPOSE: Because they are not well established, we investigated the technical success and recurrence rates of n-butyl 2-cyanoacrylate (NBCA) embolization of spinal dural arteriovenous fistulae (SDAVF), and assessed clinical outcomes. METHODS: We retrospectively studied all patients with SDAVF treated by NBCA embolization at our institution over an 8-year period. Gait and micturition disabilities were analyzed. Follow-up periods averaged 3.1 years (range, 1 month to 8.9 years). RESULTS: NBCA embolization was feasible in 74% (20/27) of patients. Of 20 patients who underwent embolization, initial embolization failure occurred in two (10%) and fistula occurrence in three (15%). All five patients in whom NBCA embolization failed underwent surgery. All patients who underwent embolization had either improved (55%) or unchanged (45%) gait disability at last follow-up. Seventeen (85%) patients had improved (40%) or unchanged (45%) micturition disability, but three (15%) had worsened. Mean Aminoff gait disability grade significantly decreased at last follow-up (2.4 [1.4] average [SD] vs 3.2 [1.4] [P = .0008]). Mean micturition disability grade decreased, but not significantly (1.4 [1.0] vs 1.7 [1.1] [P = .28]). CONCLUSION: NBCA embolization of SDAVF was technically feasible in 75% of patients. Initial apparent successful embolization was achieved in 90%; the fistula recurrence rate (failure to occlude the draining vein) for NBCA was 15%. Comparing favorably to surgical series, NBCA embolization of SDAVF appears efficacious, significantly improving mean gait disability by almost one grade at last follow-up. Close clinical and angiographic surveillance is mandatory. Longer and more uniform follow-up is needed to determine if clinical improvement and stabilization after NBCA embolization are sustained.

Aged↗

PubMed2000

Endoscopic management of cysticercal cysts within the lateral and third ventricles.

OBJECT: In this report the authors review their 3-year experience with the endoscopic management of patients with hydrocephalus who harbored cysticercal cysts within the third and lateral ventricles. The management plan was to utilize an endoscopic approach to remove the cysts and to incorporate techniques useful in treating obstructive hydrocephalus. The ultimate goals were to avoid having to place a complication-prone cerebrospinal fluid shunt and to eliminate the risk of complications related to cyst degeneration. METHODS: A retrospective analysis of 10 patients with hydrocephalus and cysticercal cysts within the third or lateral ventricles who were endoscopically managed was performed. A general description of the instrumentation and technique used for removal of the intraventricular cysts is given. At presentation, neuroimaging revealed findings suggestive of obstructive hydrocephalus in eight patients. Seven of the 10 patients treated endoscopically were spared the necessity of shunt placement. Three successful third ventriculostomies and one therapeutic septum pellucidotomy were performed. Despite frequent rupture of the cyst walls during removal of the cysts, there were no cases of ventriculitis. The endoscopic approach allowed successful removal of a cyst situated in the roof of the anterior third ventricle. One patient suffered from recurrent shunt obstructions secondary to a shunt-induced migration of cysts from the posterior fossa to the lateral ventricles. CONCLUSIONS: The endoscopic removal of third and lateral ventricle cysticercal cysts, combined with a third ventriculostomy or septum pellucidotomy in selected cases, is an effective treatment in patients with hydrocephalus and should be considered the primary treatment for this condition.

Adult↗

PubMed1999

Retrograde transvenous perfusion.

Serious consequences of stroke dictate that new approaches to the treatment of stroke be investigated. We have developed a method for perfusing the patient's own arterial blood retrograde through the venous system to ischemic brain tissue. This treatment has proven beneficial in preventing and reversing serious injury in the laboratory and in a small clinical trial. The laboratory investigation has also demonstrated that this therapy, retrograde transvenous neuroperfusion, can be coupled with hypothermia to potentially increase its benefit. History, experimental development, and the clinical trial are reviewed in this article.

Adult↗

PubMed1999

Endoscopic resection of colloid cysts: surgical considerations using the rigid endoscope.

OBJECTIVE: Colloid cysts of the third and lateral ventricles have traditionally been treated by transfrontal and transcallosal microsurgical resection or by stereotactic aspiration. Recently, rigid and flexible ventricular endoscopic techniques have been used to treat these lesions. Our study was undertaken to examine the efficacy of rigid endoscopy in the resection of colloid cysts. METHODS: Fifteen patients with a radiological diagnosis of colloid cysts were given the option of undergoing either endoscopic surgery or craniotomy. The average tumor size was 1.43 cm. Fourteen patients underwent planned endoscopic resections, and a craniotomy was performed initially in one patient. RESULTS: Entire tumor resection was achieved with the endoscope in 12 patients (86%). A craniotomy was required for two colloid cysts that could not be resected endoscopically. In total, complete radiographic resections were achieved in 14 patients (93%). There were no permanent complications, although postoperative deficits included short-term memory loss and hemiparesis, each in one patient. CONCLUSION: Rigid endoscopy affords good optical resolution, high magnification, and excellent illumination. Total or near total resection of colloid cysts should be the goal for all patients and can be achieved using the rigid endoscope, with little morbidity, shortened operative time, reduced length of stay, and resolution of symptoms. Although long-term follow-up is needed, we think that endoscopy should be considered as a primary treatment for most patients.

Adult↗

PubMed1999

Endovascular treatment of multiple intracranial aneurysms by using Guglielmi detachable coils.

OBJECT: The purpose of this paper is to present the authors' experience with Guglielmi detachable coil (GDC) embolization of multiple intracranial aneurysms and to evaluate the results of this therapy in single-stage procedures. METHODS: Clinical and angiographic evaluations were performed in 38 consecutive patients with multiple intracranial aneurysms treated by GDC embolization between March 1990 and October 1997. Twenty-nine patients presented with subarachnoid hemorrhage (SAH), four with mass effect, and five were asymptomatic. These 38 patients harbored 101 aneurysms, 79 of which were treated with GDCs, 14 by surgical clipping, and eight were left untreated. Of the GDC-treated lesions, a complete endovascular occlusion was achieved in 55 aneurysms (70%), and 24 (30%) presented neck remnants. Twenty-five patients (66%) underwent GDC embolization of more than one aneurysm in the first session. Eighteen (86%) of 21 patients with acute SAH underwent treatment for all aneurysms within 3 days after admission (15 of 21 in one session). Follow-up angiographic studies in 30 patients demonstrated an unchanged or improved result in 94% of the aneurysms (59 lesions) and coil compaction in 6% (four lesions). The overall clinical outcome was excellent in 34 patients (89%), good in one (3%), fair in one (3%), and death in two (5%). CONCLUSIONS: Endovascular treatment of multiple intracranial aneurysms, regardless of their location, with GDCs was performed safely in one session, even during the acute phase of SAH. Treatment of all aneurysms in one session protected the patient from rebleeding and eliminated the risk of mistakenly treating only the unruptured aneurysms.

Adolescent↗

PubMed1998

Retrograde transvenous neuroperfusion: a back door treatment for stroke.

BACKGROUND AND PURPOSE: Stroke is the third leading cause of death and the leading cause of adult disability in the United States. The clot-lysis drug tissue plasminogen activator is the only treatment that has been effective for acute stroke patients, yet there are significant limitations to its use and effectiveness. In this study retrograde transvenous neuroperfusion (RTN) was evaluated for its efficacy in reversing acute ischemia, preventing paralysis, and limiting pathological evidence of infarction in baboons. METHODS: Ten adult male baboons underwent 3.5 hours of reversible middle cerebral artery occlusion (MCAO) under isoflurane (0.25% to 1.5%) anesthesia. Five randomly chosen animals received RTN treatment 1 hour after start of MCAO. Somatosensory evoked potentials were recorded during MCAO. Animals were assigned daily neurological scores. Animals were killed 6 days after MCAO, and brains were quantitatively analyzed for infarct volume. RESULTS: Within 1 hour after RTN was started, treated animals showed significantly improved somatosensory evoked potentials (103.3% versus 75% of baseline; P<0.01). Likewise, the combined neurological score for the RTN-treated group was 99.2, while the combined mean score for the untreated group was 66.4 (P<0.015). The mean infarction volume was 8.8+/-3.1% (of contralateral hemisphere) for the control group and 0.3+/-0.2% for the RTN-treated group (P<0.01). No increased mortality was seen in the RTN-treated group. CONCLUSIONS: We conclude that RTN treatment during MCAO effectively reverses the pathophysiological sequelae of ischemia, even when the treatment is initiated 1 hour after the onset of ischemia. Although the infarct volume in the control group was variable when quantitatively assessed 6 days after 3.5 hours of MCAO, virtually no evidence of infarcts was seen in the RTN-treated group.

Animals↗

PubMed1998

Unruptured aneurysms presenting with mass effect symptoms: response to endosaccular treatment with Guglielmi detachable coils. Part I. Symptoms of cranial nerve dysfunction.

OBJECT: Embolization of intracranial aneurysms by using Guglielmi detachable coils (GDCs) is proving to be a safe method of protecting aneurysms from rupture. Occasionally, patients with unruptured intracranial aneurysms present with symptoms related to the aneurysm's mass effect on either the brain parenchyma or cranial nerves. In the present study, the authors conducted a retrospective review to evaluate the response to GDC embolization in a series of 19 patients presenting with cranial nerve dysfunction due to mass effect. METHODS: Aneurysms were classified by size, shape, wall calcification, and amount of intraluminal thrombus. Patients were classified by duration of symptoms prior to GDC treatment (range < 1 month to > 10 years). Clinical assessment was performed within days of the GDC procedure and at later follow-up appointments (range 1-70 months, mean 24 months). In the immediate post-GDC period, four patients experienced worsening of cranial nerve deficits. Two of the four patients had transient worsening of visual acuity, which later improved to better than baseline status. Another patient who had presented with headache and seventh and eighth cranial nerve deficits from a vertebrobasilar junction aneurysm had improvement in these symptoms, but developed a new diplopia. The fourth patient had worsening of her visual acuity, which had not resolved at the 1-month follow-up examination; this patient later underwent surgical decompression. CONCLUSIONS: On late follow-up review, the response was classified as complete resolution of symptoms in six patients (32%), improvement in eight patients (42%), no significant change in four patients (21%), and symptom worsening in one patient (5%). Patients with smaller aneurysms and those with shorter pretreatment duration of symptoms were more likely to experience an improvement in their symptoms following GDC treatment, although statistical significance was not reached in this series (p=0.603 and p=0.111, respectively). The presence of aneurysmal wall calcification (six patients) or intraluminal thrombus (12 patients) showed no correlation with the response of mass effect symptoms in these patients.

Adult↗

PubMed1998

Endoscopy and stereotaxy for aneurysms.

The combination of the endoscope and frameless stereotaxy improves surgical results by allowing the surgeon to look around structures and into tight spaces, monitor the success of aneurysm clipping, decrease the risk of perforator or cranial nerve injury, plan the surgical approach, and track surgical instruments in the surgical field. This article discusses the use of endoscopy and frameless stereotaxy in aneurysm surgery.

Adult↗

PubMed1997

Intracranial aneurysms treated with the Guglielmi detachable coil: midterm clinical results in a consecutive series of 100 patients.

A prospective study was designed to evaluate clinical outcome in a series of 100 consecutively treated patients who underwent endovascular embolization of 104 intracranial aneurysms using Guglielmi detachable coils (GDCs). Midterm clinical outcome (2-6 years, average 3.5 years) was obtained for 94 patients and was classified according to a modified Glasgow Outcome Scale. Of nine patients treated in the acute phase of severe subarachnoid hemorrhage (Grade IV or V), seven died from the initial hemorrhage, one had a poor outcome, and one had a fair midterm outcome, with no post-GDC embolization hemorrhages. Twenty patients underwent subsequent surgical or endovascular procedures that did not include the use of GDCs. These included aneurysm clipping in nine patients and parent vessel sacrifice in 11 patients. None of these 20 patients experienced post-GDC embolization hemorrhage. The postoperative midterm clinical outcomes of these 20 patients did not significantly differ from the outcomes of patients who underwent GDC embolization as their definitive treatment. Six patients died of unrelated causes prior to reaching the 2-year survival point, with no post-GDC embolization hemorrhage. The midterm outcomes of the remaining 61 patients who underwent GDC embolization as their definitive treatment were classified as excellent (46 patients [75%]), good (seven patients [11%]), fair (three patients [5%]), poor (one patient [2%]), or dead (four patients [7%]). All four patients died from giant lesions. At midterm follow up, the surviving 57 patients' neurological statuses were unchanged or improved in 54 cases and worsened in three cases. The midterm post-GDC embolization hemorrhage rate was 0% for small aneurysms, 4% (one case) for large aneurysms, and 33% (five cases) for giant lesions. The GDC procedure is a safe, effective, and reliable means of preventing aneurysm hemorrhage in patients with small and large intracranial aneurysms. Results, however, are less satisfactory in cases involving giant lesions. Further follow-up review is necessary to establish durability in the longer term. Patients with Grade IV or V subarachnoid hemorrhage in this series generally had poor outcomes even if the GDC procedure was successful in occluding the aneurysm.

Adult↗

PubMed1994

Thalamostriate artery aneurysm within the third ventricle. Case report.

The authors report the case of a 7-mm saccular aneurysm, located within the third ventricle and arising from the distal portion of a thalamostriate artery. The patient presented with an intraventricular hemorrhage and was treated via a frontotemporal craniotomy with translamina-terminalis approach for resection of the aneurysm. The etiology of the aneurysm was presumed to be idiopathic. Previously only one other third ventricular aneurysm has been reported. An intraventricular aneurysm arising from a perforating artery should therefore be considered as a rare cause of an intraventricular hemorrhage. Potential surgical approaches to third ventricular aneurysms are discussed.

Aged↗

PubMed1990

Ischemic brain rescue by transvenous perfusion in baboons with venous sinus occlusion.

We studied brain retroperfusion in nine adult baboons. Experiments in four baboons determined techniques and the safety of retroperfusion, and experiments in three baboons determined the ability of retroperfusion to reverse cerebral ischemia. Two baboons died before retroperfusion. Arterial blood was continuously circulated by an external pumping system from one femoral artery into the intracranial sinuses through specially designed balloon-tipped catheters placed percutaneously into the sigmoid sinuses bilaterally. The balloons intermittently occluded the sinuses. Ischemia was produced by occluding the left middle cerebral artery. Standard and computed electroencephalography with topographic mapping monitored the onset and reversal of ischemia. Retroperfusion rate exceeded 50 ml/min with a mean intrasinus pressure increase of 27 (0-149) mm Hg in all seven experiments. Venograms demonstrated complete or partial filling of the superior sagittal sinus in each experiment. Four experiments without ischemia established maximal balloon occlusion cycles, retroperfusion rates, and sinus pressure changes. These four baboons were neurologically normal after retroperfusion; two had normal magnetic resonance imaging scans. Ischemic changes, detected by electroencephalography following middle cerebral artery occlusion, were reversed with retroperfusion in all three ischemia experiments. Autopsies in the seven baboons demonstrated no parenchymal hemorrhage or edema. Our results suggest that further investigation of retroperfusion, and possibly retroinfusion of agents for cerebral protection, is warranted.

Animals↗

PubMed1988

Diltiazem protects against functional changes in chronic cerebrovasospasm in monkeys.

Diltiazem given 48 hours before experimental subarachnoid hemorrhage protects the cerebral vasculature of monkeys against the widespread cerebrovascular spasm seen on angiography after 5-6 days and against associated neurologic defects. In vitro examination of the cerebral arteries from treated monkeys shows that compared with untreated animals, the functional changes in the vascular smooth muscle cells, the increase in arterial wall stiffness, and the decrease in contractility, all of which were prominent in untreated monkeys, were relatively small. Other changes such as abnormal spontaneous myogenic tone, decreased responsiveness to constrictor and dilator nerve activation, and other indexes of neuronal function were little influenced by the drug. We suggest that chronic cerebrovasospasm may be initiated by the combined action of exceptionally high concentrations of a number of putative spasmogens causing injury to the larger cerebral arteries. However, the later development of intractable spasm is related to the location of blood clot and to the involvement of the vascular wall in an inflammatory process. The combined insult results in pathologic changes in the artery wall resulting in increased thickness and stiffness. Diltiazem acts on cerebrovascular smooth muscle in lower concentrations than on smooth muscle in other vascular beds, interfering with calcium entry through receptor-operated and potential-sensitive channels, and may protect against calcium-induced cell death through these and additional actions. Protection against early events presumably prevents the genesis of the subsequent chronic state.

Animals↗

PubMed1988

Early treatment with diltiazem reduces delayed cerebral vascular narrowing after subarachnoid hemorrhage.

Using a primate model of subarachnoid hemorrhage, we have demonstrated the ability of diltiazem to reduce delayed, experimental narrowing of cerebral vessels under clinically realistic conditions. Twelve monkeys were treated identically, except that six received oral diltiazem (20 mg/kg t.i.d.) starting 24 hours after a subarachnoid hemorrhage (SAH) and continuing for 5 days. Neurological examination showed that all untreated monkeys were hyperreflexic and hypotonic on the side contralateral to the SAH. Only two of the six of the diltiazem-treated monkeys had a similar deficit. Control angiograms taken before the SAH were compared with those taken 5 days later. The average vessel diameter at six standard sites in monkeys without diltiazem was 61% of control, whereas the average diameter at the same positions in the diltiazem-treated monkeys was 92% of control (P less than 0.01). In each group, the diameter of the most narrowed artery of each monkey was compared with values at the same site before SAH. The average diameter in the untreated group was 22% of control, significantly smaller than the corresponding value from the diltiazem-treated group, which was 68% (P less than 0.005). Delaying diltiazem treatment until 24 hours after hemorrhage still provides some protection, but less than that given by pretreatment with the drug. This suggests that the processes that eventually result in chronic cerebral vascular narrowing are initiated during the 24-hour period immediately after SAH. We propose that there is initially an acute, severe, calcium-dependent contraction of vascular smooth muscle and associated injury to the vessel wall, including its innervation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1986

Magnetic resonance imaging of craniopharyngioma.

Craniopharyngiomas are common tumors located in the suprasellar region. Contrast enhancement, cyst formation, and calcification are the three characteristic features of craniopharyngiomas on computed tomographic scan. More than 90% of suprasellar craniopharyngiomas exhibit at least two of these three features, thus providing easy radiologic detection. We treated a 41-year-old man in whom a large suprasellar craniopharyngioma producing severe visual loss was not detected by computed tomography but was easily identified with magnetic resonance imaging. Thus, despite high-resolution computed tomographic scan, large suprasellar craniopharyngiomas can be missed. Magnetic resonance imaging may be superior to computed tomography in detecting these tumors.

Adult↗

PubMed1986

Head trauma.

Head injury is a common occurrence in the multiply injured patient. Because it is so common, physicians in busy emergency rooms should be well versed in its evaluation and treatment. A guide to appropriate evaluation and treatment has been established by Becker et al. Patients can be divided into four categories, depending on degree of neurologic injury. Group I patients suffer transient loss of consciousness only and then return to normal; they require observation only. Group II patients suffer loss of consciousness and continue to have impaired cognitive functions; they require observation and a CT scan. Group III patients suffer loss of consciousness, continue to have disordered cognitive functions, and have significant motor deficits. This group can be subdivided into patients with and without focal neurologic deficits. Both of these will require aggressive therapy to control intracranial hypertension, CT scanning, and possibly surgery. The last category, group IV, includes patients who meet the requirements of brain death. No further work-up or therapy is needed for this group. Patients who suffer head injury are at risk for many complications, but two that are emphasized are postconcussion seizures and the postconcussion syndrome. Identifying factors that predispose the patient to these complications can help to minimize their occurrence.

Brain Concussion↗

PubMed1985

Experimental chronic cerebrovascular spasm in the monkey: an assessment of the functional changes in the cerebral arteries and their protection by diltiazem.

The structure and function of cerebral arteries obtained from a monkey model of chronic cerebral vascular spasm 5 days after hemorrhage have been examined. Narrowing of the larger cerebral arteries demonstrated by angiography at all sites of measurement seems to be due primarily to an increased wall rigidity associated with cellular damage, the resultant inflammatory response and large, long-lasting spontaneous increases in muscle tone. Changes in agonist sensitivity were extremely variable. The reduction of contractility of the vessel wall to a mean of 30% of control diminished the consequence of any changes in active tone characteristics. Neurogenic control on the side of the lesion was remarkably depressed. When treated with diltiazem, beginning 1 day before induction of hemorrhage and continuing to the time of sacrifice, arterial diameter was reduced at only 1 of the 6 standard sites of measurement and then by only a small amount. Neurologic effects invariably seen in the untreated monkeys were prevented by diltiazem. Many of the changes in the artery wall, including structural alterations, were diminished by the drug. Abnormal spontaneous myogenic tone was present but was less in the diltiazem-treated group; however, nerve damage and its functional consequences were not prevented. It is concluded that diltiazem, presumably by preventing the accumulation of intracellular calcium within the cell, prevents the initial events in the evolution of chronic cerebrovasospasm or narrowing. This is probably achieved by a diminishing of the direct vasoconstrictor effects and the toxicity of putative spasmogens released from blood clots, nerves and the brain on the vascular smooth muscle, thus interrupting the sequence leading to pathologic change.

Animals↗

PubMed1985

Effect of diltiazem on experimental chronic cerebral vasospasm in the monkey.

The influence of diltiazem on chronic cerebral vasospasm was studied following subarachnoid hemorrhage (SAH) in a primate model. The model mimics the human experience including the production of neurological deficits. Six monkeys were pretreated with diltiazem (25 mg/kg twice daily) for 2 days prior to surgical production of an SAH and for 5 days after the hemorrhage. This group was compared with six untreated monkeys that also sustained an SAH. The mean diameter of cerebral arteries measured at six angiographic sites was 60.6% of the pre-SAH diameter for the untreated group and 99.7% for the diltiazem-treated group. These values are significantly different (p less than 0.0005). There was no neurological deficit in the pretreated animals. The mean diameter of the "most constricted vessel" in each experiment was 22% of the prehemorrhage diameter for the untreated and 84% for the treated group (p less than 0.0005). Arterial pressure was unaffected by the dosage regimen. These experiments with this primate model of chronic cerebral vasospasm demonstrate that vascular narrowing and neurological deficit can be markedly attenuated by diltiazem pretreatment.

Animals↗