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

Cushing’s Syndrome-Addison’s Disease-Pheochromocytoma-Surgical Significance of the Renal Fascia-Aortic Aneurysms-Embolic Blockage of the Abdominal Aorta-

Cushing’s Syndrome

Suprarenal cortical hyperplasia is the most common cause of Cushing’s syndrome, the clinical manifestations of which include moon-shaped face, truncal obesity, abnormal hairiness (hirsutism), and hypertension; if the syndrome occurs later in life, it may result from an adenoma or carcinoma of the cortex.

Addison’s Disease

Adrenocortical insufficiency (Addison’s disease), which is characterized clinically by increased pigmentation, muscular weakness, weight loss, and hypotension, may be caused by tuberculous destruction or bilateral atrophy of both cortices.

Pheochromocytoma

Pheochromocytoma, a tumor of the medulla, produces a paroxysmal or sustained hypertension. The symptoms and signs result from the production of a large amount of catecholamines, which are then poured into the bloodstream. Because of their position on the posterior abdominal wall, few tumors of the suprarenal glands can be palpated. CT scans can be used to visualize the glandular enlargement; however, when interpreting CT scans, remember the close relationship of the suprarenal glands to the crura of the diaphragm.

Surgical Significance of the Renal Fascia

The suprarenal glands, together with the kidneys, are enclosed within the renal fascia; the suprarenal glands, however, lie in a separate compartment, which allows the two organs to be separated easily at operation

Aortic Aneurysms

Localized or diffuse dilatations of the abdominal part of the aorta (aneurysms) usually occur below the origin of the renal arteries. Most result from atherosclerosis, which causes weakening of the arterial wall, and occur most commonly in elderly men. Large aneurysms should be treated by open surgical repair. Endovascular repair can also be used by the introduction of a stent graft through one of the iliac arteries with access through the femoral arteries in the groin.

Embolic Blockage of the Abdominal Aorta

The bifurcation of the abdominal aorta where the lumen suddenly narrows may be a lodging site for an embolus discharged from the heart. Severe ischemia of the lower limbs results

Surface Landmarks of the Abdominal Viscera-Gallbladder-Spleen-Liver-Pancreas-Kidneys-Stomach-Aorta

Surface Landmarks of the Abdominal Viscera

Gallbladder

The gallbladder is a pear-shaped sac,The fundus of the gallbladder lies opposite the tip of the right ninth costal cartilage—that is, where the lateral edge of the right rectus abdominis muscle crosses the costal margin

 

Spleen

It lies in the left upper quadrant and lies under cover of the 9th, 10th, and 11th ribs. Its long axis corresponds to that of the 10th rib, and in the adult it does not normally project forward in front of the midaxillary line. In infants, the lower pole of the spleen may just be felt

Liver

The liver is a large organ that occupies the upper part of the abdominal cavity is covered under  the lower ribs, and most of its bulk lies on the right side.
In infants, until about the end of the third year, the lower margin of the liver extends one or two fingerbreadths below the costal margin. In the adult who is obese or has a welldeveloped right rectus abdominis muscle, the liver is not palpable. In a thin adult, the lower edge of the liver may be felt a fingerbreadth below the costal margin. It is most easily felt when the patient inspires deeply and the diaphragm contracts and pushes down the liver.

 

Pancreas

The pancreas lies across the transpyloric plane. The head lies below and to the right, the neck lies on the plane, and the body and tail lie above and to the left.

 

Kidneys

the left kidney lies at a slightly  higher level than The right kidney (because of the bulk of the right lobe of the liver), and the lower pole can be palpated in the right lumbar region at the end of deep inspiration in a person with poorly developed abdominal muscles. Each kidney moves about 1 in. (2.5 cm) in a vertical direction during full respiratory movement of the diaphragm. The normal left kidney, which is higher than the right kidney, is not palpable. On the anterior abdominal wall, the hilum of each kidney lies on the transpyloric plane, about three fingerbreadths from the midline. On the back, the kidneys extend from the 12th thoracic spine to the 3rd lumbar spine, and the hili are opposite the 1st lumbar vertebra

Stomach

The stomach is a dilated part of the alimentary canal between the esophagus and the small intestine ,The cardioesophageal junction lies about three fingerbreadths below and to the left of the xiphisternal junction (the esophagus pierces the diaphragm at the level of the10th thoracic vertebra).

The pylorus lies on the transpyloric plane just to the right of the midline. The lesser curvature lies on a curved line joining the cardioesophageal junction and the pylorus. The greater curvature has an extremely variable position in the umbilical region or below.

Aorta

The aorta lies in the midline of the abdomen and bifurcates below into the right and left common iliac arteries opposite the 4th lumbar vertebra—that is, on the intercristal plane. The pulsations of the aorta can be easily palpated through the upper part of the anterior abdominal wall just to the left of the midline.

Aneurysm and Coarctation of the Aorta-Patent Ductus Arteriosus

Aneurysm and Coarctation of the Aorta

The arch of the aorta lies behind the manubrium sterni. A gross dilatation of the aorta (aneurysm) may show itself as a pulsatile swelling in the suprasternal notch.

Coarctation of the aorta is a congenital narrowing of the aorta just proximal, opposite, or distal to the site of attachment of the ligamentum arteriosum. This condition is believed to result from an unusual quantity of ductus arteriosus muscle tissue in the wall of the aorta. When the ductus arteriosus contracts, the ductal muscle in the aortic wall also contracts, and the aortic lumen becomes narrowed. Later, when fibrosis takes place, the aortic wall also is involved, and permanent narrowing occurs.

Clinically, the cardinal sign of aortic coarctation is absent or diminished pulses in the femoral arteries of both lower limbs. To compensate for the diminished volume of blood reaching the lower part of the body, an enormous collateral circulation develops, with dilatation of the internal thoracic, subclavian, and posterior intercostal arteries. The dilated intercostal arteries erode the lower borders of the ribs, producing characteristic notching, which is seen on radiographic examination. The condition should be treated surgically

Patent Ductus Arteriosus

The ductus arteriosus represents the distal portion of the sixth left aortic arch and connects the left pulmonary artery to the beginning of the descending aorta. During fetal life, blood passes through it from the pulmonary artery to the aorta, thus bypassing the lungs. After birth, it normally constricts, later closes, and becomes the ligamentum arteriosum. Failure of the ductus arteriosus to close may occur as an isolated congenital abnormality or may be associated with congenital heart disease. A persistent patent ductus arteriosus results in high-pressure aortic blood passing into the pulmonary artery, which raises the pressure in the pulmonary circulation. A patent ductus arteriosus is life threatening and should be ligated and divided surgically.