Biomedical subjects

Walter Montanera

Publications and source records attributed to Walter Montanera.

5 recordsLinked to original sources

PubMed2003

Neurologic complications of cerebral angiography: prospective analysis of 2,899 procedures and review of the literature.

PURPOSE: To prospectively identify risk factors for neurologic complications related to cerebral angiography. MATERIALS AND METHODS: A total of 2,899 consecutive cerebral digital subtraction angiograms obtained with nonionic contrast material were prospectively evaluated. Neurologic complications were categorized as transient (<24 hours), reversible (24 hours to 7 days), and permanent (>7 days). The neurologic complication rate was correlated with patient age, type of indication for catheter angiography, medical history, fluoroscopic time, number and size of catheters, type and number of vessels injected, operator experience, and the quartile in which the study was performed. The correlations were statistically analyzed with Fisher exact tests and a multiple logistic regression model. RESULTS: There were 39 (1.3%) neurologic complications in 2,899 procedures; 20 were transient (0.7%), five (0.2%) were reversible, and 14 (0.5%) were permanent. Neurologic complications were significantly more common in patients 55 years of age or older (25 of 1,361; 1.8%) (P =.035), in patients with cardiovascular disease (CVD) (20 of 862; 2.3%) (P =.004), and when fluoroscopic times were 10 minutes or longer (24 of 1,238; 1.9%) (P =.022). The neurologic complication rate was higher in procedures performed by fellows alone (24 of 1,878; 1.3%) compared with that when staff alone performed the procedures (three of 598; 0.5%), but the difference was not significant (P =.172). Neurologic complications were lower in the fourth quartile of the study (six of 171; 0.9%) compared with the first quartile (16 of 776; 2.1%), which was likely due to fewer patients being examined for carotid stenosis or ischemic stroke and fewer patients with CVD (P =.085). CONCLUSION: Age-related vascular disease accounted for the failure to lower the neurologic complication rate of cerebral angiography despite technical advances.

Adolescent↗

PubMed2002

Idiopathic spinal cord herniation: report of eight cases and review of the literature.

STUDY DESIGN: A case series of eight patients with idiopathic spinal cord herniation and a review of the literature. OBJECTIVE: To report on this rare entity, provide insight on its natural history, and propose an optimal management strategy. SUMMARY OF BACKGROUND DATA: Idiopathic spinal cord herniation is a rare disease with 50 cases reported before the current study. METHODS: Eight cases (follow-up 1 month to 8 years) are reported using available information from patient charts, interviews, and assessments. All imaging studies are reviewed. The review of the literature was performed using PUBMED. RESULTS: Four patients, followed without surgical intervention, have not progressed. Of the three patients who underwent surgical repair by one of the authors, two improved and one was unchanged. A fourth patient, who was initially treated by another surgeon who failed to identify the dural defect and herniation, had a poor outcome. CONCLUSION: The pathophysiology of the dural defect is still uncertain. The typical presentation is Brown-Séquard syndrome. Microsurgical repair in cases with progression of neurologic deficits is usually successful in achieving recovery of function or arrest of progression.

Adult↗

PubMed2002

Large and deep brain arteriovenous malformations are associated with risk of future hemorrhage.

BACKGROUND AND PURPOSE: The correlation between features present in brain arteriovenous malformations (AVMs) such as size, location, and angioarchitecture at presentation with subsequent risk of hemorrhage may be valuable in predicting the behavior of AVMs and therefore guiding management. METHODS: We prospectively followed up 390 patients with brain AVMs at the University of Toronto Vascular Malformation Study Group. Location, size, angioarchitecture details, blood supply, and clinical presentation were recorded at baseline. Intracranial hemorrhages during follow-up were recorded. Significant factors from univariate analyses were used to construct a multivariate model relating the above features to the occurrence of hemorrhage. RESULTS: Thirty-eight patients had bleeding caused by the AVM in a follow-up of 1205 patient-years (mean, 3.1 years per patient). In analyses adjusted for multiple AVM characteristics, large AVMs bled more frequently than small lesions (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.41 to 4.35; P<0.0001), and deep-seated AVMs had more bleeding in follow-up than those located at superficial sites (OR, 5.56; 95% CI, 2.63 to 12.5; P<0.0001). CONCLUSIONS: Deep-seated and large AVMs were significantly more prone to hemorrhage during prospective follow-up. The distinction between factors associated with hemorrhagic presentation and the natural history risk of hemorrhage will be emphasized.

Adult↗

PubMed2002

Angioarchitectural factors present in brain arteriovenous malformations associated with hemorrhagic presentation.

BACKGROUND AND PURPOSE: Associations between clinical presentation of brain arteriovenous malformations (AVMs) and their angioarchitecture have been described. This study aims to identify significant factors related to the initial hemorrhagic event through multivariate statistical methodology. METHODS: The authors studied the initial clinical presentation of 390 consecutive patients with brain AVMs at the University of Toronto Vascular Malformation Study Group. Angiographic features present at that time, such as location, size, and blood supply, were recorded following a standard protocol and associated, through multivariate analysis techniques, with type of presentation. RESULTS: Patients had hemorrhagic presentation in 146 cases (37.4%). Hemorrhage was the initial presentation in 59.5% of the deep-seated AVMs (odds ratio [OR]=3.26; 95% CI=1.15 to 9.2; P=0.03). A single draining vein was associated with bleeding at presentation in 57.6% AVMs (OR=1.78; 95% CI=1.12 to 2.82; P=0.01), and 72.8% of the patients with venous ectasia had bleeding as initial evidence (OR=3.9; 95% CI=1.63 to 9.28; P=0.002). Hemorrhage was the initial presentation in 47.6% (111/233) of AVMs <3 cm, 22.5% (32/142) in sizes between 3 and 6 cm, and 20% in malformations >6 cm (3/15), but these differences were not significant in multivariate analyses. CONCLUSIONS: For initial hemorrhagic presentation, a small number of draining veins, deep location, and the presence of venous ectasias were significant associated factors. In contrast with many previous reports, AVM size was not associated with hemorrhage at presentation in adjusted analyses.

Adult↗

PubMed2002

The developing stroke: management decisions.

Radiologists have become important members of a multidisciplinary team aimed at treating stroke. New studies such as the NINDS (National Institute of Neurological Disorders and Stroke) intravenous and PROACT II (prolyse in acute cerebral thromboembolism II) intra-arterial thrombolytic trials for acute stroke have focused attention on the need for rapid management. Radiologists play a key role in the diagnosis and selection of patients who may benefit from these therapies. We review current issues in the computed tomographic and magnetic resonance imaging diagnosis of acute stroke and the data supporting the various treatment options.

Acute Disease↗