Angiographically occult and spontaneously thrombosed large brain arteriovenous malformation / Malformación arteriovenosa cerebral grande, angiográficamente oculta y espontáneamente trombosada

Treatment for brain arteriovenous malformations (AVM) include combinations of surgery, radiosurgery and embolization. Very rarely, spontaneous obliteration may occur, especially among small lesions with single superficial vein drainage and prior bleeding. We report the case of a large symptomatic AVM, without history of hemorrhage or prior treatment, in which self-obliteration was noted at surgery. Although MRI suggested the presence of an AVM, no evidence of arterial anomaly was observed in the brain angiography. At surgery, a large cortical nidus with tortuous arterial vessels, resembling that of an AVM but without blood flow, was identified. Complete resection was easily performed without relevant bleeding. The histopathologic study confirmed the diagnosis of a thrombosed AVM. Despite the low probability of recanalization, surgical resection of a suspected spontaneously obliterated AVM may be warranted, in order to reach a definitive diagnosis and to avoid the risk of an eventual bleeding, especially among younger patients (AU)

El tratamiento de las malformaciones arteriovenosas (MAV) cerebrales incluye combinaciones de cirugía, radiocirugía y embolización. Muy rara vez, ocurre una obliteración espontánea, fundamentalmente en MAV pequeñas, con drenaje venoso único superficial y antecedente de sangrado previo. Presentamos un caso de MAV sintomática grande, sin sangrado ni tratamientos previos, en la que se constató auto-trombosis espontánea. Aunque las imágenes de resonancia sugerían la presencia de una MAV, la arteriografía no mostró anomalía arterial compatible. En la cirugía se evidenció un nidus cortical con vasos tortuosos, idéntico a una MAV clásica, aunque sin flujo sanguíneo, por lo que pudo resecarse sin dificultad. La anatomía patológica confirmó la presencia de una MAV trombosada. A pesar del relativamente bajo riesgo de recanalización, la cirugía de una posible MAV trombosada puede ser una opción recomendable, con objeto de llegar al diagnóstico definitivo y evitar un eventual riesgo de sangrado, especialmente en personas jóvenes (AU)

Angiographically occult and spontaneously thrombosed large brain arteriovenous malformation.

Treatment for brain arteriovenous malformations (AVM) include combinations of surgery, radiosurgery and embolization. Very rarely, spontaneous obliteration may occur, especially among small lesions with single superficial vein drainage and prior bleeding. We report the case of a large symptomatic AVM, without history of hemorrhage or prior treatment, in which self-obliteration was noted at surgery. Although MRI suggested the presence of an AVM, no evidence of arterial anomaly was observed in the brain angiography. At surgery, a large cortical nidus with tortuous arterial vessels, resembling that of an AVM but without blood flow, was identified. Complete resection was easily performed without relevant bleeding. The histopathologic study confirmed the diagnosis of a thrombosed AVM. Despite the low probability of recanalization, surgical resection of a suspected spontaneously obliterated AVM may be warranted, in order to reach a definitive diagnosis and to avoid the risk of an eventual bleeding, especially among younger patients.