Natural history of ascending thrombosis of the abdominal aorta.

During 1980, 30 patients underwent successful operations for ascending thrombosis of the abdominal aorta in its three forms: low (below the inferior mesenteric artery, 11 patients); middle (above the inferior mesenteric artery, 6 patients); and high (at the level of the renal arteries, 13 patients). An angiogram that reveals high ascending thrombosis of the abdominal aorta is paradoxically more favorable than one that reveals middle or low ascending thrombosis of the abdominal aorta. In fact, the patient with a juxtarenal thrombosis has already overcome two of the three phases that constitute the critical moments of potential failure of the collateral circulation. Progressive ascending thrombosis with a poor prognosis and a rapidly downward course can cause acute ischemia with paraplegia of the legs and intestinal infarction. Most patients die suddenly in the emergency or intensive care unit from paraplegia, acute abdomen, or anuria; the latter is due to further progressive thrombosis with obstruction of the orifice of the renal arteries. On the basis of the angiogram only (apart from subjective symptoms), ascending thrombosis of the abdominal aorta constitutes an absolute indication for surgical treatment.