SUPERIOR MESENTERIC ARTERIOGRAPHY IN EXPERIMENTAL MESENTERIC VENOUS THROMBOSIS.

Abstract

THE CLINICAL and roentgenographic diagnosis of acute mesenteric vascular occlusion is difficult (2) and frequently delayed, with a resultant high mortality (1). A reliable method is required for the early detection and differentiation of mesenteric venous and arterial obstruction. The purpose of this paper is to report the angiographic findings in dogs subjected to superior mesenteric arteriography after experimental induction of thrombosis of the superior mesenteric vein. Material and Methods Seven mongrel dogs, each weighing 14 to 24 kg, were fasted for twelve hours and then anesthetized with 25 mg of intravenous sodium pentobarbital per kilogram of body weight. An endotracheal tube was inserted, and the animals were ventilated with a Harvard piston respirator (Model 607A). A celiotomy was performed, and in the first 3 dogs a small polyethylene catheter was introduced into the superior mesenteric artery from an arteriotomy in the adjacent aorta. In subsequent dogs the preferable technic was to pass a curved-tip red Odman-Ledin catheter2 1 em into the superior mesenteric artery from a femoral artery cutdown. The superior mesenteric vein was isolated and doubly ligated with silk sutures immediately proximal to its confluence with the inferior mesenteric vein (Fig. 1). Control superior mesenteric arteriography was carried out in each animal with 30 ml of 60 per cent methylglucamine diatrizoate3 injected in approximately two seconds by a Cordis injector. Roentgeno-grams of the abdomen were obtained for sixteen seconds in the anteroposterior projection with a 10 × 12-in. Schonander film changer, usually at a rate of 1 exposure per second. Eastman Kodak Royal Blue films were exposed at a target-film distance of 40 inches. A Siemens Tridoros 4 three-phase generator and the following technical factors were used: 400 rna, 0.02 seconds, and 72–80 kv. After a ten-minute pause, a mixture of 333 units of bovine topical thrombin and 2.0 ml of 75 per cent sodium diatrizoate4 was injected into the superior mesenteric vein about 1 cm proximal to the ties (Fig. 1). The bowel loops were replaced in the abdominal cavity, and the anterior abdominal wall was approximated. After a five-minute pause, superior mesenteric arteriography was repeated. In all but 1 dog a third examination was performed thirty to sixty minutes later. Identical exposure factors, amounts of contrast material, and injection pressures were used, as in the control examinations. Because of the slower flow of contrast material, the film program was prolonged up to fifty seconds, exposures usually being made at a rate of 1 every three seconds. Results The control superior mesenteric arteriograms showed reflux of contrast medium into the aorta in only 2 dogs. The arteries were numerous, large, and tapered gradually without evidence of stretching.