Association of noninvasive markers of coronary artery reperfusion to assess microvascular obstruction in patients with acute myocardial infarction treated with primary angioplasty.

Early restoration of coronary artery patency through primary angioplasty limits infarct size and improves survival. Increasing evidence, however, suggests that microvascular obstruction is often present despite coronary artery recanalization. This may limit the benefits of reperfusion therapy. We studied the use of noninvasive markers of coronary artery reperfusion as indicators of microvascular obstruction and determinants of prognosis in 98 patients with acute myocardial infarction (AMI) who were successfully treated with primary angioplasty (Thrombolysis In Myocardial Infarction grade 3 flow and residual stenosis <30%). Plasma creatine kinase (CK) levels and 12-lead electrocardiograms were performed on admission, at 90 minutes, and at 6, 12, and 24 hours after treatment. We defined: (1) reperfusion as resolution of ST-segment elevation >50% at 90 minutes, with peak CK levels within 12 hours, and T-wave inversion within 24 hours; and (2) failed reperfusion, as the absence of these parameters. Of the 98 patients studied, 87 (88.8%) had reperfusion and 11 (11.2%) had failed reperfusion. Infarct location was anterior (versus inferior) in 9 patients in the failed reperfusion group (81.8%) compared with 41 patients in the reperfusion group (47.1%) (p <0.01). Congestive heart failure >24 hours after presentation or in-hospital death occurred in 11 patients (12.6%) in the reperfusion group versus 5 (45.5%) in the failed reperfusion group (p <0.01). One-year survival was 96.1% for the reperfusion group and 60.6% for the failed reperfusion group (p <0.0001). We conclude that the association of noninvasive markers of reperfusion better identifies patients with microvascular obstruction among those who had a "successful" primary angioplasty. Evidence of impaired microvascular reperfusion is associated with a poor in-hospital and 1-year outcome.

Holmium laser-assisted coronary angioplasty in acute ischemic syndromes.

BACKGROUND AND HYPOTHESIS: Initial studies have shown holmium laser to be effective in ablation of coronary atheroma, and small studies that it may be helpful in ablation of thrombotic stenoses. Therefore, holmium laser-assisted coronary angioplasty was studied in 85 consecutive patients with acute ischemia syndromes. METHODS: Indications for therapy were acute myocardial infarction (MI) in 7 patients (8%), post-MI ischemic in 32 patients (38%), and crescendo angina pectoris in 46 patients (54%). Coronary morphology characteristics by multivessel angioplasty prognosis group criteria were Type A in 9 (10%), Type B1 in 15 (18%), Type B2 in 44 (52%), Type C in 17 patients (20%). RESULTS: Angiographic evidence of thrombus was seen in 37 (44%) of patients. The laser successfully crossed the total length of the coronary narrowing in 76 patients (89%). Procedure/clinical success was 92% for the total study population, 100% for patients with acute MI, 94% for post-MI ischemia patients, and 89% for patients with crescendo angina. Lesions with and without thrombus had identical procedure success rates. Major complication rate was 3.5%, (deaths 0%, Q-wave MI 0%, and emergent bypass surgery 3.5%). Six-month angiographic restenosis rate (> 50% stenosis) was 45%. CONCLUSION: Holmium laser-assisted balloon angioplasty appears promising in the treatment of acute ischemic syndromes and thrombotic coronary lesions.

Postprocedural hypotension after carotid artery stent placement: predictors and short- and long-term clinical outcomes.

PURPOSE: To describe the predictors of persistent hypotension after carotid artery stent (CAS) placement and define the clinical outcome of patients with this hemodynamic disturbance. MATERIALS AND METHODS: One hundred forty CAS procedures were performed in 133 consecutive patients. Post-CAS hypotension-defined as a greater than 40 mm Hg decrease in arterial pressure without evidence of hypovolemia, with a systolic pressure lower than 90 mm Hg at the end of CAS and lasting at least 1 hour-was observed in 25 patients (group 1); 108 patients did not have hypotension (group 2). RESULTS: Post-CAS hypotension developed in 33.9% of cases after balloon-expandable stent placement versus in 13.6% of cases after self-expanding stent placement (P =.04). In-hospital minor ipsilateral strokes occurred in 16% of cases in group 1 versus in 3% of cases in group 2 (P =.03). There was one (0.9%) major stroke (transient) and three (2.6%) transient ischemic attacks, all of which occurred in group 2 (not significant vs group 1 for both conditions). At 10 months +/- 4 (SD) of follow-up, there was greater total mortality in group 1 than in group 2 (20% vs 4%, P =.02), whereas neurologic events did not differ significantly between the groups. CONCLUSION: Hypotension due to carotid sinus stimulation is frequent after CAS with balloon-expandable stents. This phenomenon correlates with increased in-hospital complications and long-term risk of death.

Traumatismos del hueso temporal / Temporary bone traumatisms

Injuries to the temporal bone are caused by high energy mechanisms. Fractures, longitudinal or transverse, are the most frequent lesions and they need to be specifically searched. If the fracture is not visible, its presence is suspected by means of indirect signs, such as soft tissue occupation within mastoid cells, or in the tympanic cavity, and air in an abnormal situation. The ossicular chain can undergo luxations, being the most frequent the incudomallear joint, and fractures. For the study of traumatic injuries of the temporal bone, the CT scan should be the method of choice, especially by means of multislice technology, since the speed of acquisition, and the good quality of multiplanar reconstructions, facilitates the diagnosis.

: Los traumatismos del hueso temporal ocurren por mecanismos de alta energía. Las fracturas, longitudinales o transversales, son las lesiones más frecuentes y deben buscarse dirigidamente. Si el rasgo de fractura no es visualizado, signos indirectos como ocupación de partes blandas en celdillas mastoideas o en la caja timpánica y aire en lugares no habituales, deberían aumentar la sospecha. La cadena de huesecillos puede lesionarse por luxaciones, la incudomaleolar es la más frecuente, o por fracturas. Para el estudio de las lesiones traumáticas del hueso temporal, la tomografía computada debe ser el método de elección, sobretodo si se realiza con tecnología multicorte ya que, la rapidez en la adquisición y la gran calidad en reconstrucciones multiplanares facilita el diagnóstico.

Resonancia magnética cerebral en daño axonal difuso / Cerebral magnetic resonance in diffuse axonal damage

El daño axonal difuso es causa importante de morbimortalidad y de secuela neuro-sicológica. En TC los hallazgos son pocos significativos o ausentes. La RM es el método diagnóstico más importante para la identificación del tipo de lesiones y ubicación de ellas. La secuencia de difusión es especialmente sensible para detectarlas, y la espectroscopía por RM puede dar información pronóstica.

Resonancia magnética del plexo braquial normal y patológico / Magnetic resonance of normal and pathological brachial plexus

El plexo braquial es una estructura nerviosa compleja que incluye desde las raíces cervicales hasta los nervios periféricos de la axila. Su valoración mediante métodos de imagen ha sido difícil, hasta la aparición de la RM. Es importante contar con un equipo de alto campo y bobinas de superficie que permitan obtener imágenes de alta resolución, debiendo siempre realizarse un examen en los tres planos del espacio. Este método ha probado ser útil en el diagnóstico de avulsión, neuromas, tumores, neuritis y fibrosis actínica entre las patologías más frecuentes

Técnica de conservación de hígado para trasplante: aspectos clínicos y experimentales / Preservation technic of liver for transplantation: clinic and experimental aspects

Desde 1963 se han realizado aproximadamente 1000 transplantes hepáticos en seres humanos. La conservación del hígado donante es un tiempo fundamental para evitar el daño anóxico irreversible del período isquémico. Se describe la técnica de conservación del hígado donante utilizado en 21 experiencias en perros y en 2 hígados humanos. En las experiencias en perros se efectuaron 9 trasplantes hepáticos y en otros 12 casos se efectuó sólo la extracción y conservación del hígado donante. En la experiencia clínica se efectuó el procedimiento en 2 oportunidades, obteniéndose además 4 riñones para trasplante. En un caso no se concretó el trasplante hepático por contraindicación del receptor (metástasis en carcinoma hepático). Se describe la técnica de perfusión in situ con soluciones frías para obtención simultánea de varios órganos donantes