Trauma to the Abdominal Aorta-Obliteration of the Abdominal Aorta and Iliac Arteries-Trauma to the Inferior Vena Cava- Compression of the Inferior Vena Cava-

Trauma to the Abdominal Aorta

Blunt trauma to the aorta is most commonly caused by headon automobile crashes. Rupture of the tunica intima and media occurs and is quickly followed by rupture of the turnica adventitia. The initial rupture of the intima and media is probably mainly caused by the sudden compression of the aorta against the vertebral column, while the delayed rupture of the adventitia is caused by the aortic blood pressure. Unless quickly diagnosed by MRI, and surgical treatment instituted, death follows.

 

Obliteration of the Abdominal Aorta and Iliac Arteries

Gradual occlusion of the bifurcation of the abdominal aorta, produced by atherosclerosis, results in the characteristic clinical symptoms of pain in the legs on walking (claudication) and impotence, the latter caused by lack of blood in the internal iliac arteries. In otherwise healthy individuals, surgical treatment by thromboendarterectomy or a bypass graft should be considered. Because the progress of the disease is slow, some collateral circulation is established, but it is physiologically inadequate. However, the collateral blood flow does prevent tissue death in both lower limbs, although skin ulcers may occur.

Trauma to the Inferior Vena Cava

Injuries to the inferior vena cava are commonly lethal, despite the fact that the contained blood is under low pressure. The anatomic inaccessibility of the vessel behind the liver, duodenum, and mesentery of the small intestine and the blocking presence of the right costal margin make a surgical approach difficult. Moreover, the thin wall of the vena cava makes it prone to extensive tears.

Because of the multiple anastomoses of the tributaries of the inferior vena cava, it is impossible in an emergency to ligate the vessel. Most patients have venous congestion of the lower limbs.

Compression of the Inferior Vena Cava

the enlarged uterus during the later stages of pregnancy is commonly compress The inferior vena cava. This produces edema of the ankles and feet and temporary varicose veins. Malignant retroperitoneal tumors can cause severe compression and eventual blockage of the inferior vena cava. This results in the dilatation of the extensive anastomoses of the tributaries. This alternative pathway for the blood to return to the right atrium of the heart is commonly referred to as the caval–caval shunt. The same pathway comes into effect in patients with a superior mediastinal tumor compressing the superior vena cava. Clinically, the enlarged subcutaneous anastomosis between the lateral thoracic vein, a tributary of the axillary vein; and the superficial epigastric vein, a tributary of the femoral vein, may be seen on the thoracoabdominal wall