PubMed Health⌕ Search

Biomedical subjects

J Ausman

Publications and source records attributed to J Ausman.

10 recordsLinked to original sources
PubMed2001

Contemporary management of subarachnoid hemorrhage and vasospasm: the UIC experience.

BACKGROUND: Cerebral vasospasm is a well-known and serious complication of aneurysmal subarachnoid hemorrhage. The means of monitoring and treatment of vasospasm have been widely studied. Each neurosurgical center develops a protocol based on their experience, availability of equipment and personnel, and cost, so as to keep morbidity and mortality rates as low as possible for their patients with vasospasm. METHODS: At the University of Illinois at Chicago, we have developed algorithms for the diagnosis and management of cerebral vasospasm based on the experience of the senior authors over the past 25 years. This paper describes in detail our approach to diagnosis and treatment of aneurysmal subarachnoid hemorrhage and vasospasm. Our discussion is highlighted with data from a retrospective analysis of 324 aneurysm patients. RESULTS: Over 3 years, 324 aneurysms were treated; 185 (57%) were clipped, 139 (43%) were coiled. The rate of vasospasm for the 324 patients was 27%. The rate of hydrocephalus was 32% for those patients who underwent clipping, and 29% for those coiled. The immediate outcomes for those who underwent clipping was excellent in 35%, good in 38%, poor in 15.5%, vegetative in 3%, and death in 8% of the patients. For those who underwent coiling the immediate outcome was excellent in 64%, good in 14.5%, vegetative in 2.5%, and death in 14.5% of the patients. These statistics include all Hunt and Hess grades. For those patients who underwent clipping, 51% were intact at 6 months follow-up, 15% had a permanent deficit, 10% had a focal cranial nerve deficit, and 2% had died from complications not directly related to the procedure. For those patients who had undergone coiling, 75% were intact at 6 months follow-up, 12.5% had a permanent deficit, and 12.5% had a cranial nerve deficit, with no deaths. CONCLUSIONS: The morbidity and mortality of cerebral vasospasm is significant. A good outcome after aneurysmal subarachnoid hemorrhage is dependent upon careful patient management in the preoperative, perioperative, and postoperative periods. The timely work-up and aggressive treatment of neurological deterioration, whether or not it is because of vasospasm, is paramount.

Algorithms↗
PubMed1999

Direct cervical internal carotid access for GDC treatment of an ophthalmic origin carotid aneurysm.

The use of detachable coils in the treatment of intracranial aneurysms continues to evolve since its introduction in 1991 [1-5]. Although not well described in the literature, technical considerations in gaining and maintaining access to intracranial aneurysms play a pivotal role in any successful endovascular treatment. Tortuosity and looping of the cervical internal carotid artery (ICA) is one problem occasionally encountered. These unusual loops, in addition to the normal turns of the carotid siphon result in less control of the microcatheter tip. This problem culminated in this case where an ophthalmic origin carotid aneurysm could not be successfully treated from the standard femoral approach due to the presence of multiple ICA turns, with the presence of a proximal cervical ICA turn being particularly bothersome. This problem was circumvented by use of direct surgical access to the cervical ICA above the cervical ICA turn, allowing for successful endovascular aneurysm treatment with detachable coils.

Aneurysm↗
PubMed1993

Determination of regional cerebral oxygen consumption in the human: 17O natural abundance cerebral magnetic resonance imaging and spectroscopy in a whole body system.

17O natural abundance imaging in a whole body imager is demonstrated using standard MRI spectrometer and 1H imaging methods. A novel design of a highly sensitive 17O/1H doubly tuned surface head coil is shown. The head probe allows simultaneous acquisition of 17O and 1H images using a single coil. The relatively low 17O signal intensity due to the low natural abundance of 17O (0.037 atom percent) is partially compensated by fast repetition of the pulse sequence, achievable due to the short spin lattice relaxation time, T1. A small number of signal averages (e.g., NEX = 50) is sufficient for obtaining images having signal to noise of about 5:1. Due to the short longitudinal relaxation time of 17O, i.e., 2-5 msec, short TR values can be used. 128 phase encoding steps with TR = 10-25 msec correspond to total acquisition time of 1 to 2.5 min. Due to the small gyromagnetic ratio of 17O and the relatively small gradients in a standard whole body system, i.e. 0.5 G/cm, the image in-plane resolution is about 3 mm and a slice thickness of 15 mm. In vivo 17O MRS and MRI natural abundance spectroscopic signals and images of human brain have been observed. The transverse relaxation time, T2 was found to be 2.00 +/- 0.17 msec at 1.5 T. MRS 17O measurements of signal intensity in the occipital cortex during inhalation of oxygen gas, 21.8% 17O enriched, showed a maximum signal enhancement of 25% within the inhalation period. The rate of the metabolism of oxygen (CMRO2) in the occipital cortex was found to be 1.5 mumole/(g tissue) in good agreement with the value of 1.435 mumole/(g tissue) given in the literature. Current measurements using higher 17O enrichments and larger quantities of 17O enriched oxygen gas will enhance resolution and provide more accurate determination of the rate of oxygen metabolism rate and blood flow. The potential of 17O imaging is thus demonstrated in physiological in vivo studies of cerebral metabolism of oxygen and blood flow.

Brain↗
PubMed1992

Stereotactic endoscopic interventions in cystic and intraventricular brain lesions.

Image guided stereotaxis is an accurate and safe method of directing therapy to target volumes defined in two-dimensional (2D) multiplanes or three-dimensional (3D) perspectives using computer reconstruction of image data. The major limitations of stereotactic techniques are related to a lack of intraoperative visualization and direct monitoring of the procedures and to changes of intracranial coordinates after decompression of cystic lesions or aspiration of cerebrospinal fluid in the management of intraventricular lesions. Endoscopic laser stereotaxis (ELS) involves integration of rigid-flexible endoscopy and Nd-YAG laser to 3D-2D multiplanar image-guided stereotactic procedures. The major advantages of ELS include: direct intraoperative visualization, hemostasis, evacuation or resection assessment, and wide exploration of intracranial cavities or ventricles. The technique allows safe aspiration, biopsy, and resection or internal decompression of deep and subcortical intracranial lesions. ELS has proved to be safe and effective in the management of 76 clinical cases and appears to be a promising technique in the management of cystic and intraventricular lesions.

Brain Diseases↗
PubMed1991

Application of multimodality imaging stereotactic localization in the surgical management of vascular lesions.

Multidimensional image preplanning and accurate pre and intraoperative localization for intracranial vascular lesions have been implemented. Methodology include carbon fiber base ring, localizer plates, any X-ray tubes, PC compatible software and intraoperative localizing unit. Surgical management of deep arteriovenous malformations is especially suitable for this technique, including the use of intraoperative digital angiography.

Cerebrovascular Disorders↗
PubMed1990

Image-guided stereotactic centered craniotomy and laser resection of solid intracranial lesions.

A technique in which solid intracranial lesions are removed using computerized image processing under stereotactic conditions is described. A specially developed carbon fiber ring holder compatible with most image studies is used as a reference system. Intraoperatively it affords freedom of patient positioning and unobstructed access to any site of the head. Four position alternatives of the aiming device allow the removal of lesions from any location. For superficial lesions located near eloquent areas, a 'centered' craniotomy is performed, usually under local anesthesia, and removal is performed using loupe magnification, bipolar coagulation ultrasonic aspiration of the Nd:YAG laser fiber in the contact or noncontact technique. In deep-seated lesions, a surgical 'corridor' is established and kept by means of retractors adapted for use with the stereotactic apparatus. Microsurgical techniques and the CO2 laser are used in solid lesions; in vascular lesions, bipolar coagulation or the ND:YAG laser can be used. Centered craniotomy allows the precise localization, enhancement, three-dimensional orientation and removal of lesions with minimal trauma to the surrounding brain. The technique has been applied in 78 cases where the extreme accuracy of the technique, benign postoperative course and short hospitalization have been impressive.

Angiography, Digital Subtraction↗