A mechanically detachable coil for the treatment of aneurysms and occlusion of blood vessels.

PURPOSETo evaluate mechanically detachable coil designs capable of controlled and instantaneous release within an aneurysm or vascular space.METHODSThree mechanically detachable coil designs, clamped ball, looped ribbon, and interlocking cylinder, were evaluated using in vitro and in vivo testing to study reliability of coil release, retractability, and coil behavior in a microcatheters. In vitro tests were performed using a glass side-wall aneurysm model and conventional microcatheters. In vivo experiments in rabbits included aneurysm models (side-wall and bifurcation) and arterial occlusions (carotid and renal).RESULTSAll three designs deployed coils easily and were able to retract coils after partial deployment. Motion was seen in previously released coils and in the catheter when using the clamped ball and looped ribbon designs. The interlocking cylinder design did not cause similar motion. When compared with the other two designs, the interlocking cylinder had significantly greater separation forces between coil pusher and coil while in the catheter. Frictional forces within the catheter were lower for the interlocking cylinder mechanically detachable coil design than for a commercially available conventional coil and coil pusher system. During in vivo testing, the mechanically detachable coil design operated smoothly in the catheter, providing good release and retraction in aneurysms and straight vessels.CONCLUSIONThe interlocking cylinder mechanically detachable coil design is superior to the other two tested designs. The mechanically detachable coil was reliably delivered and detached in in vivo testing for the treatment of aneurysms and for the occlusion of blood vessels.     

Correlation of pressure measurements with angiographic characteristics predisposing to hemorrhage and steal in cerebral arteriovenous malformations.

PURPOSETo determine whether there is a physiologic explanation for the predisposition of patients with certain angiographic characteristics to symptoms of hemorrhage and steal.METHODSSuperselective transcatheter feeding arterial pressure and mean arterial pressure measurements were obtained before embolotherapy in 32 patients with cerebral arteriovenous malformations. Pressures were correlated with previously described angioarchitectural characteristics predisposing to hemorrhage and steal. These included size of the arteriovenous malformation, feeding artery length, venous drainage pattern, and angiomatous change.RESULTSThe feeding arterial pressure and feeding arterial pressure/mean arterial pressure ratios were significantly decreased in patients with angiomatous change. Feeding arterial pressure and feeding arterial pressure/mean arterial pressure ratios progressively decreased as lesions went from peripheral, to mixed, to central venous drainage. A trend for lower feeding arterial pressure was also demonstrated with greater feeding pedicle length. A statistically significant correlation could not be demonstrated between feeding arterial pressure or feeding arterial pressure/mean arterial pressure ratios and size of the arteriovenous malformation, hemorrhage, or symptoms of steal.CONCLUSIONSFeeding arterial pressure measurements help provide a physiologic basis for the relationship between certain angiographic characteristics and hemorrhage and steal symptoms in patients with arteriovenous malformation.     

Antidepressant drug use in an ambulatory elderly population: A 14-year overview

The objective of the work was to identify changes in antidepressant drug use and determine if the prevalence of antidepressant use has changed over 14 years. A longitudinal analysis comparing antidepressant drug use at 14 yearly intervals from 1978–79 to 1991–92 was undertaken using the longitudinal health screening program of ambulatory elderly participants (Florida Geriatric Research Program). Participants included all subjects screened in the Florida Geriatric Research Program from 1 August 1978 to 31 July 1992. The outcome measures were self-reported antidepressant drug use. Approximately 3.0 per cent (range of 2.3 to 3.2 per cent over 14 yearly intervals) of participants in this program reported the use of an antidepressant drug. There was no statistically significant change in antidepressant use between 1978–79 and 1991–92 (p > 0.6630). Across all study intervals women reported more frequent use of antidepressant drugs than men. In 1991–92, amitriptyline and imipramine represented over 50 per cent of all antidepressant drug use in this elderly population. Less than 6 per cent of all antidepressant drug use was for fluoxetine, the newest selective serotonin uptake inhibitor. The majority of elderly patients are receiving older tertiary amine tricyclic antidepressants such as amitriptyline, imipramine and doxepin that are not the preferred drugs for the elderly. Educational programs are needed to improve antidepressant prescribing for geriatric patients.     

Mediastinitis in heart transplantation.

Between March 1985 and December 1991, mediastinitis developed in 12 of 420 cardiac transplantation patients (2.8%). The mortality rate in this group of patients was 8.3% (1/12). Actuarial survival (1 year, 75%; and 5 years, 65%) was not significantly different from that of the group without mediastinitis (1 year, 88%; and 5 years, 75%). A higher percentage of the patients in the group with mediastinitis were listed as UNOS status 1 (50% versus 35%) and had a history of previous sternotomies (58% versus 44%). The presentation of mediastinitis was typical. Computed tomographic scanning with or without aspiration was a valuable adjunct in the diagnosis of mediastinitis. Induction immunotherapy with minimal steroids in the perioperative period was used in all patients. This may contribute to the patients' ability to mount an appropriate and effective response to infection, permitting earlier diagnosis. The debridement irrigation technique used in 8 of 12 patients had a low success rate of 33%, whereas the debridement muscle flap technique used in 4 of 12 was 100% successful in eliminating infection.     

Clinical and educational telepsychiatry applications: a review.

OBJECTIVE: Telepsychiatry in the form of videoconferencing brings enormous opportunities for clinical care, education, research, and administration. Focusing on videoconferencing, we reviewed the telepsychiatry literature and compared telepsychiatry with services delivered in person or through other technologies. METHODS: We conducted a comprehensive review of telepsychiatry literature from January 1, 1965, to July 31, 2003, using the terms telepsychiatry, telemedicine, videoconferencing, effectiveness, efficacy, access, outcomes, satisfaction, quality of care, education, empowerment, and costs. We selected studies for review if they discussed videoconferencing for clinical and educational applications. RESULTS: Telepsychiatry is successfully used for various clinical services and educational initiatives. Telepsychiatry is feasible, increases access to care, enables specialty consultation, yields positive outcomes, allows reliable evaluation, has few negative aspects in terms of communication, generally satisfies patients and providers, facilitates education, and empowers parties using it. Data are limited with regard to clinical outcomes and cost-effectiveness. CONCLUSIONS: Telepsychiatry is effective. More short- and long-term quantitative and qualitative research is warranted on clinical outcomes, predictors of satisfaction, costs, and educational outcomes.