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Vascular surgeon, radiologist

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Computed Tomography of the retroperitoneal space

Alexey Portnov, medical expert
Last reviewed: 19.10.2021

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Aneurysms

Ectasia or abdominal aortic aneurysms usually develop due to atherosclerosis. Often they are accompanied by parietal thrombosis. The abdominal aorta is considered an aneurysmally altered when the dilatation of the free lumen of the vessel reaches 3 cm or the outer diameter exceeds 4 cm. In patients with asymptomatic course, surgical intervention is usually justified if the aneurysm diameter reaches 5 cm. The overall condition of the patient and the rate of expansion are assessed. The risk of rupture of an aneurysm with a bleeding is reduced if the free lumen of the vessel is located centrally, and thrombotic masses surround it more or less evenly from all sides.

The risk of rupture of an aneurysm increases if the free lumen is located eccentrically, or the contour of the vessel in the cross section is very uneven. Expansion of the lumen more than 6 cm in diameter also increases the risk of aneurysm rupture. When planning surgical treatment, it is necessary to know whether there is involvement of the renal, mesenteric and iliac arteries in the process, and to what extent. Sudden pain often accompanies an aneurysm rupture or stratification. This process can spread from the thoracic to the abdominal aorta. A dynamic CT scan with amplification allows you to see a patch of aneurysm bundle.

Phlebothrombosis

In the case of thrombosis of the veins of the lower extremities in phlebography, it is not always possible to clearly determine whether the thrombus spreads to the veins of the pelvis. The contrast drug, which was injected into the superficial vein of the foot, is often so diluted with blood that it becomes difficult to assess the lumen of the femoral / iliac veins. In this case it is necessary to conduct a KT-study with intravenous administration of contrast medium.

The width of the lumen of a freshly vein vein is usually at least twice as large as normal. The thrombosed segment is uniformly or partially hypodense compared to the adjacent artery. In non-occlusive lesions, the thrombus is visualized as a filling defect within the lumen of the vein. In the case shown in the sections to the right, the thrombus spreads through the left common iliac vein to the caudal part of the inferior vena cava, where it is defined as a hypodense zone surrounded by a blood stream enhanced by contrast. CT sections of the inferior vena cava should be continued cranial until the signs of thrombosis disappear.

When a contrast medium is injected into the superficial vein of the foot, a satisfactory quality of contrast is observed only in the veins of the corresponding lower limb. To assess the venous network of the pelvis, contrast agent is more suitable to inject into the veins of the upper limb. If one side is occluded, collateral circulation through the venous venous network develops. In the absence of thrombus dissolution in deep veins, it can be created surgically. You must be careful not to confuse the inguinal lymph nodes with the physiological gipodensnye gates ("symptom of the fat gates").

To avoid the development of PE in thrombosis of the inferior vena cava. The patient must remain immobile until the thrombus is covered by the endothelium or dissolved by the therapy. Occasionally, a pronounced collateral circulation through the lumbar veins develops.

Depending on the size of the thrombus and the individual characteristics of the course of the process, surgical intervention can be indicated-probing the vessel with thrombectomy. If the process recurs, an arteriovenous shunt is performed to rule out re-thrombosis. At the subsequent control of the effectiveness of the therapy, color duplex ultrasound or phlebography is usually performed.

Enlargement of lymph nodes

Density of the lymph nodes is about 50 HU, which corresponds to the density of muscles. Lymph nodes up to 1.0 cm in diameter are usually considered unchanged, 1.0 - 1.5 cm - borderline, more than 1.5 cm - pathologically enlarged. The enlarged lymph nodes are usually located in the mesentery, between the aorta and the inferior vena cava) and para-aortic).

It is very important to know the main ways of lymph drainage from the pelvic organs. For example, from gonads lymphatic drainage is carried out directly into the lymph nodes at the level of the kidneys. In a testicular tumor, metastases are detected in the para-aortic lymph nodes around the renal vessels, and not in the iliac. While with cancer of the bladder, uterus or prostate gland should be especially carefully examine the iliac lymph nodes.

A conglomerate of lymph nodes around the aorta and its large branches, such as the celiac trunk, is a typical sign of non-Hodgkin's lymphoma.

trusted-source [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13]

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