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Biomedical subjects

W R Marsh

Publications and source records attributed to W R Marsh.

At least 55 records · Page 3Linked to original sources
PubMed1989

Management of spinal dural arteriovenous malformations.

Dura-based spinal arteriovenous malformations (AVM's) are being diagnosed with increasing frequency. The optimal management of such lesions remains a topic of discussion. In an effort to guide this discussion, the authors review their experience with 17 cases of spinal dural AVM treated between January, 1984, and July, 1987. All patients presented with a slowly progressive paraparesis. The abnormalities were initially identified on myelography and confirmed by selective spinal angiography. Fourteen patients underwent endovascular embolization as a primary treatment, and a total of 18 embolization procedures were performed. After all but two of these, obliteration was confirmed at angiography. Patients' symptoms improved following 15 or these procedures but early improvement was not sustained in 10 instances; patients were unchanged after two procedures and worse after one. Follow-up angiography was performed at varying intervals after 15 of the 18 procedures, and recanalization of the previously obliterated spinal dural AVM was demonstrated in 13 instances. Eight patients ultimately underwent surgical treatment of their dura-based spinal AVM. No patient suffered deterioration of symptoms following operation. While embolization may allow angiographic obliteration of a spinal dural AVM and early clinical improvement, for the majority of patients these are not sustained. The average time to treatment failure was 5 months. Newer embolization materials will be necessary to effect permanent treatment in many of these patients.

Aged↗
PubMed1988

Orbital expansion in plagiocephaly.

In moderate to severe plagiocephaly, the transverse diameter of the orbit on the affected side is consistently decreased. In these cases, the supraorbital rim has been expanded by the required amount and bone grafted. This makes for greater orbital symmetry and ease in obtaining the correct supraorbital convexity. Ten patients have been handled in this way with satisfactory postoperative results.

Craniosynostoses↗
PubMed1988

Selective posterior cerebral artery Amytal test for evaluating memory function before surgery for temporal lobe seizure.

Selective testing for memory function with Amytal (amobarbital) in the posterior cerebral artery (PCA) is a promising modification of that test in the internal carotid artery (ICA). This new technique, performed with a Tracker catheter system, was completed successfully in 17 of 20 patients being examined before planned surgery for refractory temporal lobe seizure. The PCA test overcomes three major problems with the ICA technique. First, with the PCA technique, memory testing is begun immediately after injection, when the drug has its peak effect. Second, when the speech-dominant hemisphere is being tested with the PCA test, patients do not become aphasic. Third, injection into the PCA delivers the drug more effectively to the target, the ipsilateral hippocampal formation.

Adolescent↗
PubMed1988

Use of MR imaging for quantitative evaluation of resection for temporal lobe epilepsy.

The postoperative magnetic resonance imaging studies of 40 patients who underwent surgery for medically refractory temporal lobe epilepsy were reviewed. A method for quantifying the resection of four specific medial temporal lobe structures--amygdala, uncus, hippocampal formation, and parahippocampal gyrus--was used to correlate postoperative seizure control with the degree to which those structures had been resected. Satisfactory postoperative seizure control was found to be strongly dependent (P less than .01) on the performance of at least partial resection of all four medial temporal lobe structures. The total amount of tissue removed did not necessarily correlate with the clinical outcome in individual cases, however, as long as some portion of all four medial structures had been resected. Two complicating factors--the presence of posterior or bilateral independent electroencephalographic foci and a history of meningoencephalitis--each negatively influenced surgical outcome (P less than .01). In cases with a complicating factor and inadequate medial resection, the outcome was invariably poor.

Adult↗
PubMed1988

Computer-assisted stereotactic biopsy of intracranial lesions in pediatric patients.

A computer-assisted stereotactic biopsy technique has been used in 30 patient (ages 5 months to 16 years) with intracranial lesions (supratentorial in 23 and infratentorial in 7). The computer program integrates stereotactically gathered imaging data and permits preoperative planning of a biopsy trajectory. Diagnostic tissue was obtained in 27 cases. In 2 cases, therapeutic interventions--third ventriculostomy and cyst aspiration--were accomplished at the time of the biopsy. There were no major complications related to the procedure; however, 2 patients had transient neurologic deficits. Computer-assisted stereotactic biopsy is a valuable diagnostic procedure in the pediatric patient with an intracranial lesion.

Adolescent↗
PubMed1988

The natural history of unruptured intracranial arteriovenous malformations.

The authors conducted a long-term follow-up study of 168 patients to define the natural history of clinically unruptured intracranial arteriovenous malformations (AVM's). Charts of patients seen at the Mayo Clinic between 1974 and 1985 were reviewed. Follow-up information was obtained on 166 patients until death, surgery, or other intervention, or for at least 4 years after diagnosis (mean follow-up time 8.2 years). All available cerebral arteriograms and computerized tomography scans of the head were reviewed. Intracranial hemorrhage occurred in 31 patients (18%), due to AVM rupture in 29 and secondary to AVM or aneurysm rupture in two. The mean risk of hemorrhage was 2.2% per year, and the observed annual rates of hemorrhage increased over time. The risk of death from rupture was 29%, and 23% of survivors had significant long-term morbidity. The size of the AVM and the presence of treated or untreated hypertension were of no value in predicting rupture.

Adolescent↗
PubMed1987

Computer-assisted stereotactic biopsy of intracranial lesions.

The use of a computer program that allows the integration of stereotactically gathered CT, MRI and digital angiographic data in the planning of a biopsy trajectory is described. This system has been used to perform 447 stereotactic biopsies in 439 patients. Intracranial hemorrhages occurred in three patients; combined morbidity and mortality was less than 1%. Incorporation of angiographic data and visualization of the surgical trajectory enhances the safety and accuracy of stereotactic biopsy of intracranial lesions.

Biopsy↗
PubMed1986

Craniofacial osteotomies to facilitate skull base tumour resection.

In order to expose deeply situated tumours of the skull base in various regions, the concept of osteotomies of segments of the facial skeleton has been developed. The portion of skeleton overlying the tumour is removed, the lesion is resected and the removed bony structure is then reinserted. This has greatly facilitated tumour removal in difficult areas. The advantages of this approach are, to the surgeon, total en bloc resection of deeply situated tumours with few complications; for the patient, an improvement in the quality of the aesthetic result following resection of recurrent or potentially lethal tumours.

Facial Bones↗
PubMed1986

Mandibular asymmetry associated with congenital muscular torticollis.

An unusual case involving an adult patient with marked facial and mandibular asymmetry secondary to congenital muscular torticollis is presented. The etiology and pathology of congenital muscular torticollis are reviewed. A team approach was used to correct this deformity. Procedures included a transcranial total orbital osteotomy, open distal myectomy of the sternocleidomastoid muscle, and a mandibular horizontal osteotomy.

Adult↗
PubMed1986

Therapeutic embolization angiography for extra-axial lesions in the head.

Percutaneous transcatheter arterial embolization has played an increasingly important role in the management of vascular lesions in the head. Embolization can promote thrombosis within vascular tumors and malformations, reduce bleeding and decrease the need for transfusion intraoperatively, and facilitate surgical approaches to otherwise unresectable lesions. It is important for the clinician to be aware of this interventional technique because many of the patients who are considered for embolization are triaged through several different clinical areas, and much can be gained from the collaboration of the clinician, the surgeon, and the angiographer. We performed 31 therapeutic particulate embolization procedures for extra-axial head lesions in 23 patients by using flow-directed techniques. Of these procedures, 11 resulted in vascular occlusion and 15 resulted in 80 to 95% obstruction, as demonstrated by angiography. In 14 patients, embolization was performed preoperatively both to decrease blood loss and to occlude inaccessible or unresectable portions of a lesion. In nine patients, embolization was the sole means of treatment for occluding an abnormal vascular shunt. Two patients (9%) experienced a minor transient neurologic change after the procedure.

Adolescent↗
PubMed1986

The risk-benefit ratio of intraoperative shunting during carotid endarterectomy. Relevancy to operative and postoperative results and complications.

The relative risk of shunting versus not shunting during carotid endarterectomy was analyzed retrospectively in 1935 cases undergoing carotid endarterectomy for carotid ulcerative stenosis. The need for shunting was based on a correlation between electroencephalographic changes and a fall in cerebral blood flow below the critical level required for adequate perfusion during the period of carotid occlusion. Patients were divided into four risk categories for surgery, based on medical and neurological risks and angiographic findings. Shunts were required in 30% of the low risk group and 56% of the high risk group. Based on the severity of reductions of cerebral blood flow during the period of carotid occlusion it is concluded that 12% of all patients would have sustained a major deficit, 15% a minor or transient deficit, and 20% a transient deficit without shunting. The risk of shunting 792 cases in this series was 0.5%. Overall minor morbidity, major morbidity, and mortality each approximated 1% in this series.

Arterial Occlusive Diseases↗
PubMed1986

Recurrent carotid stenosis. Results and complications of 57 operations.

Among 1992 patients undergoing carotid endarterectomy from January 1972 through December 1984, 57 operations were performed in 51 patients for recurrent carotid stenosis. Thirty-four of these cases had undergone initial surgery at this institution while 23 had endarterectomy elsewhere. Fifty-two of the 57 operations were for symptomatic disease while five were for evidence of a progressing lesion. All operative procedures were monitored with intracerebral blood flow measurements and continuous electroencephalograms. Twenty-three patients required intraoperative shunting. There were no complications related to shunt usage or to the period of temporary occlusion in patients who did not require shunting. Recurrent stenosis was related to intimal hyperplasia in 14 cases, recurrent atherosclerosis with interluminal thrombi or degenerated plaque in 27, unexplained soft thrombus in eight, proximal scarring in six, and to aneurysms in two. Intimal hyperplasia was the most common cause for restenosis within 2 years from the date of surgery and developed earlier in patients with a primary closure than in patients closed with a patch graft. The operative complication rate was 10.5% or 4 times the risk of surgery for primary atherosclerosis at this institution. Complications were attributed primarily to intraoperative and postoperative thromboembolic events related to apparent increased thrombogenicity of these vessels. The highest complication rate occurred in the group of patients undergoing surgery for thrombotic material in the internal carotid artery, either primary or with underlying atherosclerosis. There were no neurological complications in the group with myointimal hyperplasia. The authors' experience suggests that on-lay patch grafting without endarterectomy should be used in patients with myointimal hyperplasia. Patients with complicated recurrent atherosclerosis can be treated with endarterectomy and patch grafting, but interposition vein grafts should be considered in cases in which the vessels are extensively damaged by the recurrent plaque or with an unexplained thrombus at the site of previous endarterectomy.

Aneurysm↗
PubMed1986

Use of the galeal frontalis myofascial flap in craniofacial surgery.

The anatomy and the technique of raising the galeal frontalis myofascial flap is described. In 38 patients with various pathologies, congenital anomalies, tumors, and trauma, this technique was employed. There were no extradural infections. The applications and complications of the flap are discussed. It is highly recommended wherever there is a possibility of direct intracranial nasopharyngeal communication.

Craniofacial Dysostosis↗
PubMed1986

The requirement for polymorphonuclear leukocytes in the late asthmatic response and heightened airways reactivity in an animal model.

The antigen-induced late asthmatic response (LAR) and subsequent heightened airways reactivity after this response have been associated with increased airways inflammation. Employing an animal model of the LAR in rabbits previously developed in our laboratory, 3 phases of experiments were performed to investigate the role of polymorphonuclear leukocytes (PML) in the LAR and heightened reactivity. In all 3 phases, airways reactivity to histamine and bronchoalveolar lavage analysis were performed 3 days before and 3 days after bronchial challenge with ragweed extract. In Phase 1, 2 groups of rabbits receiving nitrogen mustard were studied: an immune group received immune serum containing antiragweed IgE, and a control group received nonimmune serum. In Phase II, nitrogen mustard was administered to immune rabbits during aortic occlusion to allow the lungs to be exposed to nitrogen mustard while limiting exposure of the bone marrow to this drug, preventing depletion of PML. In Phase III, both an immune and a nonimmune group of rabbits received nitrogen mustard as in Phase I; however, prior to antigen challenge, they were repleted with a neutrophil-rich population of PML. In all experiments, no group of control (nonimmune) rabbits, whether depleted or repleted of PML, developed an immediate asthmatic response (IAR) or a LAR. In addition, no significant increases in lavage cells or airways reactivity occurred after ragweed challenge. In contrast, those animals receiving immune serum and nitrogen mustard developed an IAR; however, no LAR occurred, and no significant change in airways reactivity was observed. Rabbits receiving immune serum and nitrogen mustard with aortic occlusion developed an IAR and LAR, and airways reactivity increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Temporal lobectomy in children with epilepsy.

The results of temporal lobectomy for medically refractory seizures are analyzed in 29 boys and 21 girls with a mean age of 15.8 years. The average age at onset of seizures was 7.5 years, and the time between onset and surgery averaged 8.3 years. Postoperatively, 27 patients (54%) were seizure-free, 12 patients (24%) had only occasional auras without loss of consciousness, five patients (10%) had fewer seizures, and six (12%) were unchanged. Therefore, 78% were essentially seizure-free and 88% benefited significantly from the operation. There was no significant change in the Wechsler Intelligence Scale scores before and after surgery; however, the shorter the time between seizure onset and surgery, the greater the likelihood of improvement in verbal and perceptual intelligence quotient. Social outcome was significantly improved, and a large percentage of patients were either in school or actively employed. Early consideration of temporal lobectomy in children with medically refractory seizures is recommended.

Adolescent↗
PubMed1986

Saphenous vein bypass grafts for giant aneurysms and intracranial occlusive disease.

The authors report their experience with the use of saphenous vein bypass grafts for treating advanced occlusive disease in the posterior circulation (77 patients, all of whom had failed medical management and showed severe ischemic symptoms), deteriorating patients with giant aneurysms of the posterior circulation (nine patients), progressive ischemia in the anterior circulation (26 patients, none of whom had a normal examination), and giant aneurysms in the anterior circulation (20 patients, all of whom presented with mass effect or subarachnoid hemorrhage). Graft patency in the first 65 cases treated was 74%. However, after significant technical changes of vein-graft preparation and construction of the proximal anastomosis, patency in the following 67 cases was 94%. Excellent or good results (including relief of deficits existing prior to surgery) were achieved in 71% of patients with advanced occlusive disease in the posterior circulation, 44% of those with giant aneurysms of the posterior circulation, 58% of those with ischemia of the anterior circulation, and 80% of those with giant aneurysms of the anterior circulation. Mean graft blood flow at surgery in the series was 100 ml/min for posterior circulation grafts and 110 ml/min for anterior circulation grafts. Experience to date indicates that this is a useful operation, and is particularly applicable to patients who are neurologically unstable from advanced intracranial occlusive disease in the posterior circulation or with giant aneurysms in the anterior circulation. The risk of hyperfusion breakthrough with intracerebral hematoma restricts the technique in patients with progressing ischemic symptoms in the anterior circulation, and the intolerance of patients with fusiform aneurysms in the posterior circulation to the iatrogenic vertebrobasilar occlusion limits the applicability of this approach to otherwise inoperable lesions in that system.

Aged↗
PubMed1986

Effect of hyperglycemia on brain pH levels in areas of focal incomplete cerebral ischemia in monkeys.

The adverse effect of a minimal cerebral blood flow (CBF) in models of global ischemia has been noted by many investigators. One factor believed important in this situation is the level of blood glucose, since a continued supply of this metabolite results in increased tissue lactate, decreased brain pH, and increased cell damage. The authors have extended these observations to a model of focal incomplete ischemia. Brain pH was measured in fasted squirrel monkeys in regions of focal incomplete ischemia after transorbital occlusion of the middle cerebral artery (MCA). In both control and hyperglycemic animals, CBF was reduced to less than 30% of baseline. At 3 hours after MCA occlusion, brain pH in the control group was 6.66 +/- 0.68 as compared to 6.27 +/- 0.26 in the glucose-treated group. This difference was statistically significant by Student's unpaired t-test (p less than 0.05). Thus, hyperglycemia results in decreased tissue pH in regions of focal incomplete cerebral ischemia in monkeys.

Animals↗