COMMENTARY

Endarterectomy for asymptomatic carotid stenosis?

Purpose: To determine carotid artery stenosis incidence after radiotherapy for head-and-neck neoplasms.

Methods and Materials: This historical prospective cohort study comprised 44 head-and-neck cancer survivors who received unilateral neck radiotherapy between 1974 and 1999. They underwent bilateral carotid duplex ultrasonography to detect carotid artery stenosis.

Results: The incidence of significant carotid stenosis (8 of 44 [18%]) in the irradiated neck was higher than that in the contralateral unirradiated neck (3 of 44 [7%]), although this difference was not statistically significant (p = 0.13). The rate of significant carotid stenosis events increased as the time after radiotherapy increased. The risk of ipsilateral carotid artery stenosis was higher in patients who had undergone a neck dissection vs. those who had not. Patients with significant ipsilateral stenosis also tended to be older than those without significant stenosis. No other patient or treatment variables correlated with risk of carotid artery stenosis.

Conclusions: For long-term survivors after neck dissection and irradiation, especially those who are symptomatic, ultrasonographic carotid artery screening should be considered.

Background: Each year, stroke occurs in 30.9 million individuals worldwide and is responsible for ∼4 million deaths. In the United States, it is the third leading cause of death, occurring with greater frequency than myocardial infarction in patients with hypertension. The greatest burden of stroke, apart from death, is serious long-term physical and mental disability. Stroke survivors often experience physical handicap, depression, and cognitive dysfunction, which together affect their daily functioning, quality of life, and survival. The treatment of stroke is associated with extremely high costs, with stroke-related illnesses responsible for >$49 billion in the United States in 2002. Despite intensive research efforts, few effective treatments are available once stroke has occurred; thus, stroke prevention should be a primary focus for all health care providers.

Objective: The purpose of this article was to review the epidemiology and burden of stroke in terms of disability, quality of life, and cost of care, and to summarize the evidence for treatments having therapeutic benefit, with an emphasis on antihypertensive agents.

Methods: Relevant studies were identified through a MEDLINE search of English-language articles published between 1990 and 2004. The search terms were stroke, epidemiology, economic impact, disability, quality of life, hypertension, drug therapy, and angiotensin II-receptor antagonists. Articles describing major clinical studies, new data, or new mechanisms pertinent to the therapy of stroke were selected for review.

Conclusions: Identifying and modifying key risk factors is crucial to reducing the morbidity and mortality of stroke. Hypertension is one of the most important risk factors for stroke, and treatment with a variety of antihypertensive agents reduces the risk. Recent evidence suggests that the angiotensin II (ATII)-receptor antagonist losartan may offer advantages beyond blood pressure lowering, including attenuation of the central aortic reflected pressure wave, molecule-specific properties, and neural protective influences on brain ATII type 2 receptors.

Valorar la utilidad diagnóstica de la angiografía RM con contraste (ARMC) en el estudio de la estenosis de la arteria carótida interna extracraneal (ACI) frente a la arteriografía con sustracción digital intraarterial (ASDIA).

Búsqueda de los artículos relevantes desde el año 1990 al 2000, utilizando las bases de datos MEDLINE y EMBA-SE. Criterios iniciales de selección: 1. Artículos que comparasen an-gio-RM con ASDIA en el estudio de estenosis de la ACI, y 2. Tamaño muestral, 10 sujetos o más. Posteriormente se seleccionaron los estu-dios con ARMC. Se estudiaron los resultados diagnósticos de la ARMC, y se valoró además la ARM sin contraste (TOF —time-of-flight—) si los estudios la incluían. Se elaboraron curvas COR e inter-valos de confianza al 95%.

En los estudios se evaluaron 324 pacientes y 648 ACI (12 artículos). Los resultados diagnósticos en la discriminación de la estenosis carotídea de la ARMC frente a la ASDIA fueron: sensibili-dad y especificidad ponderadas, 97,28% y 97,08%, respectivamente. Se observó una diferencia significativa a favor de la ARMC frente a la ARM TOF en dichos valores (p = 0,08 y p < 0,001, respectivamente).

Las técnicas ARM demuestran una capacidad diag-nóstica muy alta en la detección de estenosis carotídea, siendo superior la técnica con contraste frente a la de sin contraste. A pesar de no ser superior a la ASDIA, dado el riesgo de morbimortalidad que esta últi-ma presenta (0,7-1,2%), muchos autores abogan porque la ARMC (asociada a la ecografía Doppler) se convierta en el método de elec-ción del estudio prequirúrgico de la estenosis de la ACI.

To evaluate the diagnostic benefit of using contrast MR Angiography (MRA) in the study of extracranial internal carotid artery stenosis as opposed to intraarterial digital subtraction arteriography (IADSA).

A search for relevant articles from 1990 to 2000 using MEDLINE and EMBASE databases. Initial selection criteria: 1. articles which compare MRA and IADSA in the study of extracranial internal carotid artery stenosis; and 2. sample size of 10 or more subjects. Studies employing contrast MRA were subsequently selected. Contrast MRA diagnostic results were studied, as were those of non-contrast MRA (TOF) if included. ROC curves and 95% confidence intervals were calculated.

In the studies, 324 patients and 648 extracranial internal carotid arteries were evaluated (12 articles). The diagnostic results in carotid artery stenosis discrimination using contrast MRA as opposed to IADSA were: sensitivity and specificity = 97.28% and 97.08%. With regard to contrast MRA vs. non-contrast MRA (TOF), significant differences favoring contrast MRA in both sensitivity and specificity were observed. (p = 0.08 and p < 0.001, respectively).

MRA techniques demonstrate very high diagnostic capabilities in the detection of carotid stenosis, with contrast MRA being more effective than non-contrast. MRA. In spite of not being superior to IADSA, given the morbimortality risk with which the latter is associated (0.7-1.2%), many authors defend contrast MRA (in association with Doppler echography) having become the method of choice for presurgical study of extracranial internal carotid artery stenosis