Female lumbosacral physiological protrusion is obvious

Introduction In the early stage of iliac vein compression syndrome, the physiological anterior protrusion of female lumbosacral is obvious. The venous hemodynamic changes of the lower extremities caused by stenosis or obstruction caused by internal and external factors of the iliac vein are the basis of the pathophysiology and evolution of the iliac vein compression syndrome. Lower extremity swelling and fatigue are the most common early symptoms at the beginning. The affected limb has only mild edema, especially when standing for a long time and sedentary. In the mid-term, as the venous return disorder increases and the venous pressure continues to rise, it will lead to deep venous valve insufficiency. Symptoms of severe deep venous insufficiency, such as calf ulcers, or thrombosis of the iliac vein.

Cause

(1) Causes of the disease

Anatomical factors

The anatomical relationship between the radial artery and the iliac vein is the basis of the iliac vein compression syndrome. The bilateral common iliac vein is located on the right side of the mid-lower plane of the fifth lumbar vertebral body, which merges into the inferior vena cava and rises along the spine. The right common iliac vein is almost straight and continuous with the inferior vena cava, while the left common iliac vein is traversed to the right from the left side of the pelvis, and is almost at right angles to the inferior vena cava before the lumbosacral vertebrae. The abdominal aorta descends from the left side of the spine and is divided into the left and right common iliac arteries in the lower limb plane of the fourth lumbar vertebral body. Therefore, the right common iliac artery crosses the left common iliac vein and then extends to the lower right of the pelvis. Studies have found that in nearly 3/4 of the human body, the right common iliac artery spans the left common iliac vein at the level of bilateral common iliac veins; 1/5 of the people are at this slightly upper level, a few are here. Below the point. In this way, the left common iliac vein is more or less pushed forward by the physiological lordosis of the lumbosacral vertebrae, and at the same time, it is pressed backwards by the right common iliac artery across its front, so that it is in an anatomical position after the front pressure. When the human body is upright and the lumbosacral height is tilted forward, the physiological lordosis is exacerbated to make the compression more obvious; when the human body is in the sitting position, the pressure is relieved or disappeared. Occasionally, the compression of the left common iliac vein originates from the low bifurcation of the abdominal aorta, the distorted left common iliac artery, the bladder, the tumor, and the ectopic kidney.

2. Abnormal structure in the venous cavity

McMurrich, Erich, and Krumbharr et al. performed anatomic observations on a large number of corpses without significant left venous venous disease, and found that the incidence of left iliac vein compression and intraluminal adhesion were 32.3%, 23.8%, and 14%, respectively. In 1956, May and Thurner proposed that 22% of the autopsy had a similar sacral structure in the left common iliac vein. This scorpion-like structure contained fibroblasts, collagen, and a large number of capillaries. Because the structure can not be found in the common iliac vein of the fetus, they believe that this is due to an acquired response of the left common iliac vein to the right common iliac artery and the fifth lumbar vertebrae. Pinsolle and other meticulous observations of the cavities and iliac vein junctions of 130 corpses, of which 121 bodies had abnormal structures in the left iliac vein. He divided it into five categories:

(1) : The sagittal triangle at the junction of the sacral venous junction protrudes perpendicularly into the small structure in the cavity.

(2) Flap: The structure of the bird's nest similar to the lateral edge of the common iliac vein.

(3) Adhesion: a fusion of a certain length and width of the anterior and posterior walls of the vein.

(4) Bridge: The long strip structure divides the lumen into 2 to 3 sections of different caliber and spatial directions.

(5) Band: The membrane-like structure causes the lumen to form a sieve-like porous change. The source and significance of abnormal structures in the common iliac vein are still controversial.

At present, it is more inclined to explain the close contact of the right common iliac artery, the lumbosacral vertebrae and the left common iliac vein, and the arterial pulsation caused repeated stimulation of the venous wall, causing chronic injury and tissue reaction of the vein. This view is mainly based on:

1 This anatomical position is fairly constant, always at the level of the right common iliac artery and the left common iliac vein;

2 there is dense fibrous tissue between the arteries and veins;

The normal intima and media of the 3 lumens were replaced by a neat connective tissue covered with a layer of normal endothelial cells. This structure is significantly different from the mechanized thrombus. Another point of view relates to congenital factors, which are considered to be significantly differently histologically distinct from the similar structures of new or inflammatory tissues. Secondly, from the perspective of embryonic development, the right common iliac vein is completely derived from the right iliac vein; the left common iliac vein is derived from the fusion of the bilateral common iliac veins, and often forms two or more conduits, the source of abnormal structures in the vein. The degradation of these pipes during development is incomplete. According to the literature, the existence of this organizational structure has a family history tendency.

3. Secondary thrombosis

On the basis of the iliac vein compression and the abnormal structure of the cavity, once the trauma, surgery, childbirth, malignant tumor or long-term bed rest, the venous return or the blood coagulation is increased, the sputum-femoral vein thrombosis can be secondary. form. Johnson et al believe that contraceptives help explain that iliac vein compression syndrome occurs in young women. Once the thrombus is formed, inflammation and fibrosis occur further in the iliac vein compression and adhesion segments, causing the iliac vein to develop from partial obstruction to complete obstruction. Due to the presence of compression and abnormal structures in the lumen, it is difficult to recanalize after the iliac vein thrombosis, making the left common iliac vein occluded for a long time and difficult to cure.

(two) pathogenesis

The venous hemodynamic changes of the lower extremities caused by stenosis or obstruction caused by internal and external factors of the iliac vein are the basis of the pathophysiology and evolution of the iliac vein compression syndrome.

Lateral vascular formation

There are abundant collateral veins in the pelvic cavity, which play an important role in slowing the hemodynamic changes of the common iliac vein compression syndrome. Taking the left common iliac vein as an example, the internal iliac vein can be passed through the internal iliac vein, the anterior iliac vein plexus and the female venous plexus. Lumbar ascending vein - middle, anterior and external veins - abdominal thoracic cavity and azygous vein; pelvic vein - vertebral vein system. Branch veins of the proximal and distal deep veins of the lower extremities also play a role in collateral circulation. The compensatory capacity of the collateral circulation is relatively strong. For example, the sum of the diameters of the left iliac vein, the lumbar ascending vein, and the middle iliac vein can be expanded by an average of 3 mm. The venous hemodynamic changes of the iliac vein compression syndrome, in the case of collateral circulation can be compensated or load, the lower limbs will not appear or only mild clinical manifestations.

2. Evolution process

The extent of hemodynamic changes depends on the degree of obstruction of the iliac vein and the resulting venous return. The evolution process is an increase in pelvic and lower extremity venous pressure - venous dilatation - secondary relative valvular insufficiency, superficial veins and varicocele. The severe expansion of the pelvic veins in women will result in the formation of so-called "variaria around the uterus."

When the lesions inside and outside the iliac vein are severe, there are obvious stenosis or obstruction. This is an anatomical factor for the occurrence of iliac vein thrombosis in the iliac vein compression syndrome. Zhang Yuanliang et al reported that the intraluminal adhesion structure can reduce the axillary vein by 4.3% to 88.6%, with an average of 33.9%. When Fu Jiaxuan et al reported 1 and 2 adhesion structures, the veins were reduced by 20% and 43%, respectively. Zhao Jun and other 35 limbs caused by deep venous thrombosis of the lower extremity caused by common venous compression syndrome, 41.7% and 100% of stenosis were 31.4% and 45.7%, respectively. This shows the role of severe stenosis and complete obstruction in venous thrombosis. It is believed that the venous stenosis is nearly 50%, and its formation rate will be greatly increased.

an examination

Related inspection

Blood routine CT examination

Initial: Lower extremity swelling and fatigue are the most common early symptoms. The affected limb has only mild edema, especially when standing for a long time and sedentary. Female lumbosacral sacral anterior protrusion is obvious, and the left lower limb will have a menstrual period similar to "adolescent lymphedema." Ferri had 3 patients with long-standing left lower extremity edema, and the angiography proved to be caused by compression of the left iliac vein. In 1993, Sloame et al studied 215 elderly people and found that the lower extremity can be concave 3mm deep edema in 88 cases, the left side is 34.5%, the right side is 6.9%, and it is believed that the left lower extremity edema is likely to be right common iliac artery compression. Left common iliac vein and associated lymphatic vessels. Therefore, for lower extremity edema without other reasons, it should be possible to have this possibility. Female patients may have prolonged menstrual period and increased menstrual flow, as well as symptoms such as swelling of the lower extremities due to pelvic visceral congestion and increased venous pressure during menstruation.

Mid-term: As the venous return disorder increases and the venous pressure continues to rise, it can lead to deep venous valve insufficiency. Once it affects the calf and the venous valve, similar symptoms to the primary deep venous insufficiency occur. It is characterized by lower extremity varicose veins, lower extremity edema, pigmentation, varicocele and so on.

Late: Symptoms of severe deep venous insufficiency, such as calf ulcers, or thrombosis of the iliac vein. The vast majority of cases reported at home and abroad were discovered during the treatment of thrombosis. Special attention should be paid to patients with non-thrombotic venous obstruction and symptomatic venous obstruction. Due to the severe stenosis of the iliac vein and the limitation of obstructive lesions, and the collateral veins are better, clinical manifestations similar but different from venous thrombosis appear. In addition, due to the original stenosis of the common iliac vein, the thrombus of the deep vein of the lower extremity is not prone to fall off and pulmonary embolism occurs.

Differential diagnosis

Brachial plexus and lumbosacral injuries after radiation: Radiotherapy is the best treatment option for breast, neck, testicular, and lymphoma, and is also most likely to cause brachial plexus and lumbosacral damage after radiation.

Lumbosacral Pain: The lumbosacral region is the hub connecting the upper body and the lower body (including the pelvis and lower limbs) in the trunk. The structure is more complicated. Four out of five adults have experienced significant lumbosacral pain in one person. It usually occurs after being exposed to the cold. In people under the age of 45, it is the most common cause of loss of working ability due to low back pain.

Initial: Lower extremity swelling and fatigue are the most common early symptoms. The affected limb has only mild edema, especially when standing for a long time and sedentary. Female lumbosacral sacral anterior protrusion is obvious, and the left lower limb will have a menstrual period similar to "adolescent lymphedema." Ferri had 3 patients with long-standing left lower extremity edema, and the angiography proved to be caused by compression of the left iliac vein. In 1993, Sloame et al studied 215 elderly people and found that the lower extremity can be concave 3mm deep edema in 88 cases, the left side is 34.5%, the right side is 6.9%, and it is believed that the left lower extremity edema is likely to be right common iliac artery compression. Left common iliac vein and associated lymphatic vessels. Therefore, for lower extremity edema without other reasons, it should be possible to have this possibility. Female patients may have prolonged menstrual period and increased menstrual flow, as well as symptoms such as swelling of the lower extremities due to pelvic visceral congestion and increased venous pressure during menstruation.

Mid-term: As the venous return disorder increases and the venous pressure continues to rise, it can lead to deep venous valve insufficiency. Once it affects the calf and the venous valve, similar symptoms to the primary deep venous insufficiency occur. It is characterized by lower extremity varicose veins, lower extremity edema, pigmentation, varicocele and so on.

Late: Symptoms of severe deep venous insufficiency, such as calf ulcers, or thrombosis of the iliac vein. The vast majority of cases reported at home and abroad were discovered during the treatment of thrombosis. Special attention should be paid to patients with non-thrombotic venous obstruction and symptomatic venous obstruction. Due to the severe stenosis of the iliac vein and the limitation of obstructive lesions, and the collateral veins are better, clinical manifestations similar but different from venous thrombosis appear. In addition, due to the original stenosis of the common iliac vein, the thrombus of the deep vein of the lower extremity is not prone to fall off and pulmonary embolism occurs.

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