Estudo comparativo de eco-Doppler com arteriografia na avaliação da doença oclusiva aorto-ilíaca / Comparative study of Doppler ultrasonography with arteriography in the evaluation of aortoiliac occlusive disease

Contexto: A arteriografia com contraste (AC) tem sido o exame tradicional de avaliação de pacientes com suspeita de doença oclusiva aorto-ilíaca (DOAI). Recentemente, métodos menos invasivos, como a eco-Doppler, têm sido usados com a mesma finalidade. Objetivo: Comparar prospectivamente a eco-Doppler com a AC e eventual manometria arterial direta (MAD) na avaliação pré-operatória de pacientes com suspeita de DOAI. Métodos: Foram submetidos a eco-Doppler e a AC 125 pacientes internados para tratamento de doença arterial oclusiva dos membros inferiores, avaliando comparativamente 552 segmentos da aorta infrarrenal e das artérias ilíacas comum e externa. As lesões encontradas foram classificadas em cinco categorias: 1) normal e estenose leve (0 a 19 por cento); 2) estenose moderada (20 a 49 por cento); 3) estenose significativa (50 a 79 por cento); 4) estenose crítica (80 a 99 por cento); e 5) oclusão total. A MAD foi usada em 19 segmentos de 15 pacientes para classificar lesões limítrofes entre duas categorias. Foram calculados índices de validade (sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e acurácia) para distinguir lesões hemodinamicamente significativas de não-significativas e para distinguir estenoses críticas de oclusões. O padrão-ouro foi AC, complementado pela MAD. Foram também calculados coeficientes de correlação kappa entre arteriografias e eco-Doppler para o conjunto dos segmentos aorto-ilíacos. Resultados: Lesões clinicamente relevantes (estenoses de 50 a 99 por cento e oclusões totais) foram observadas na eco-Doppler em 163 segmentos (29,5 por cento) e na AC em 158 segmentos (28,6 por cento). A eco-Doppler mostrou altos índices de validade para distinguir lesões hemodinamicamente significativas de lesões não-significativas em todos os segmentos (acurácia = 92 por cento; kappa = 0,81) e para diferenciar estenoses críticas de oclusões (acurácia = 86 por cento; kappa = 0,73). Os índices ...

Background: Contrast arteriography (CA) has been the traditional method of evaluation of patients with suspected aortoiliac occlusive disease (AIOD). Recently, less invasive methods, such as Doppler ultrasonography, have been used for the same purpose. Objective: The present study prospectively compares Doppler ultrasonography with CA and direct arterial manometry (DAM) in the preoperative evaluation of patients with suspected AIOD. Methods: A total of 125 patients admitted for treatment of arterial occlusive disease of the lower extremities underwent Doppler ultrasonography and CA, comparatively evaluating 552 aortic, common iliac e external iliac segments. The lesions found were classified into five categories: 1) normal and mild stenosis (0-19 percent); 2) moderate stenosis (20-49 percent); 3) significant stenosis (50-79 percent); 4) critical stenosis (80-99 percent); and 5) total occlusion. DAM was used in 19 segments of 15 patients to classify borderline lesions. Validity indexes (sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy) were calculated to distinguish hemodynamically significant from non-significant stenosis and to discriminate critical stenosis from total occlusions. The gold standard was CA, supplemented by DAM. Correlation coefficients (kappa statistics) between arteriography and Doppler ultrasonography were also calculated for the whole sample of aortoiliac segments. Results: Clinically relevant lesions (stenoses between 50-99 percent and total occlusions) were observed on Doppler ultrasonography in 163 segments (29.5 percent) and on CA in 158 segments (28.6 percent). Doppler ultrasonography showed high validity indexes to distinguish hemodynamically significant from non-significant lesions (overall accuracy = 92 percent; kappa = 0.81) and an overall accuracy of 86 percent (kappa = 0.73) to distinguish critical stenosis from total occlusion. Optimal correlation coefficients ...

Acetylcholine and bradykinin enhance hypotension and affect the function of remodeled conduit arteries in SHR and SHR treated with nitric oxide donors

Discrepancy was found between enhanced hypotension and attenuated relaxation of conduit arteries in response to acetylcholine (ACh) and bradykinin (BK) in nitric oxide (NO)-deficient hypertension. The question is whether a similar phenomenon occurs in spontaneously hypertensive rats (SHR) with a different pathogenesis. Wistar rats, SHR, and SHR treated with NO donors [molsidomine (50 mg/kg) or pentaerythritol tetranitrate (100 mg/kg), twice a day, by gavage] were studied. After 6 weeks of treatment systolic blood pressure (BP) was increased significantly in experimental groups. Under anesthesia, the carotid artery was cannulated for BP recording and the jugular vein for drug administration. The iliac artery was used for in vitro studies and determination of geometry. Compared to control, SHR showed a significantly enhanced (P < 0.01) hypotensive response to ACh (1 and 10 æg, 87.9 ± 6.9 and 108.1 ± 5.1 vs 35.9 ± 4.7 and 64.0 ± 3.3 mmHg), and BK (100 æg, 106.7 ± 8.3 vs 53.3 ± 5.2 mmHg). SHR receiving NO donors yielded similar results. In contrast, maximum relaxation of the iliac artery in response to ACh was attenuated in SHR (12.1 ± 3.6 vs 74.2 ± 8.6 percent in controls, P < 0.01). Iliac artery inner diameter also increased (680 ± 46 vs 828 ± 28 æm in controls, P < 0.01). Wall thickness, wall cross-section area, wall thickness/inner diameter ratio increased significantly (P < 0.01). No differences were found in this respect among SHR and SHR treated with NO donors. These findings demonstrated enhanced hypotension and attenuated relaxation of the conduit artery in response to NO activators in SHR and in SHR treated with NO donors, a response similar to that found in NO-deficient hypertension.

Comportamiento de las ondas de flujo de arterias uterinas e iliacas externas durante contracciones de trabajo de parto / Behavior of flow waves of uterine and external iliac arteries during labor contractions

Para comprender mejor la adaptación fisiológica de los flujos sanguíneos durante el trabajo de parto observamos los comportamientos de las velocidades de flujo en las arterias uterinas e íliacas externas en 15 embarazadas de término, sin patologías y en trabajo de parto franco. La edad materna fue de 21,6 ñ 5,2 años promedio ñ DS, la paridad de 0,6 ñ 0,5 partos y la edad gestacional de 39,2 ñ 1,1 semanas. Todos los partos fueron vaginales sin complicaciones, el peso de los recién nacidos fue de 3,440 ñ 621g, y el apgar de 8,6 ñ 1,6 y 9,0 ñ 0,7 al 1-5 min. En la arteria uterina la relación sístole/diástole y el índice de resistencia aumentaron de 1,83 ñ 0,25 durante la relajación a 4,24 ñ 1,55 durante la contracción p<0,05 y de 0,46 ñ 0,05 durante la relajación a 0,74 ñ 0,08 durante la contracción p<0,01 respectivamente. En todas las pacientes se observó en la arteria ilíaca externa un flujo diastólico reverso durante la relajación uterina, el cual persistió sólo en 2 pacientes durante la contracción p<0,01, además esta onda de flujo modificada con la hiperventilación materna. Concluimos que la contracción uterina produce cambios significativos en las velocidades de flujo en las arterias uterinas e ilíacas externas, las cuales pudieran ser explicadas por un aumento de la resistencia durante la contracción uterina, con un desvío del flujo sanguíneo hacia territorios de menor resistencia