Excessive limb growth and thickening

Introduction Limb growth and excessive thickening are one of the clinical manifestations of congenital arteriovenous fistula. Congenital arteriovenous fistula is caused by abnormal development of the embryonic primordium during the evolution process, resulting in abnormal traffic between arteries and veins.

Cause

The primordial blood vessels and blood cells are mesenchymes originating from the mesoderm. When the early embryonic body segments have not yet formed, in the outer neutrophils of the yolk sac and the pedicle, some cells concentrate to form a cell group of different sizes, called the blood island. . The blood islands gradually stretch and connect to each other to form the original capillary plexus. Arteries and veins originate from the same capillary plexus at the same time.

The embryonic development process of blood vessels can be roughly divided into three stages: the plexus stage, the reticular stage and the tube trunk formation stage. During the reticular period, if the enlarged vascular traffic is concentrated and tends to fuse together, arteriovenous fistula can be produced. In histology, there are countless parallel blood vessels that are incompletely fused, and there are many traffic to each other. These traffic are often extremely small and called micro arteriovenous fistulas. During the formation of the trunk, the abnormally extensive traffic between the general circulatory arteries and veins is called the great arteriovenous fistula. There is still much debate about what causes vascular primordia dysplasia to form vascular malformations.

Some scholars believe that congenital arteriovenous fistula is the inheritance of chromosomal abnormalities. However, Desaive and Bessone had 840 congenital malformations, and only 7 cases suggested a genetic history. In early pregnancy, toxic infections, metabolic disorders, abnormal position of the fetal position and umbilical cord cause compression trauma, which can affect normal fetal development. Endocrine and autonomic dysregulation can also affect the development of arteries, veins, and lymphatic systems.

an examination

Related inspection

Limb fluoroscopy, limb examination, CT examination, vascular ultrasound

Auxiliary inspection:

1. Arteriography When atherectomy is determined and the residual arteriovenous fistula after surgery has been determined, angiography is required. Arterial angiography can show the situation of arteriovenous traffic, but sometimes it is difficult. The angiography shows that many abnormal blood vessels can not recognize the direct communication of arteries and veins. The input trunk artery can be dilated and distorted due to increased blood flow; the contrast agent accumulates in the ankle; and changes such as varicose veins are output to diagnose congenital arteriovenous fistula.

2, deep vein retrograde angiography of the lower extremity: can show the return flow of deep venous valve insufficiency.

3, percutaneous venous cannulation: can be positioned to detect the function of each pair of valves in the femoral vein.

4, the measurement of peripheral venous pressure and PaO2 measurement: can reflect the reflux congestion, indirectly understand the valve function, and because of the simple and easy operation, it is often used as a screening test. In the presence of arteriovenous fistula, the venous pressure around the fistula increases, and the venous blood PaO2 content increases.

5, color ultrasound examination: can understand the arterial blood shunt, the direction of blood flow in the vein and the phase of vascular noise.

6, venous blood oxygenation examination of the venous blood oxygenation of the lesions in the same part of the healthy side of the venous blood oxygen content increased.

Diagnosis: According to medical history and physical examination, diagnosis is generally not difficult. Congenital arteriovenous fistula is accompanied by varicose veins. Therefore, in young people or children, when varicose veins are found without obvious causes, especially in unilateral or uncommon areas, the possibility of congenital arteriovenous fistula should be considered. If the patient is found to have limb growth, thickening, hairy, sweating and other diseases, the diagnosis is even more doubtful.

Differential diagnosis

Limb shortening deformity: congenital tibia lack of patient claudication, calf shortening. It can be seen that the humerus arch deformity, the foot valgus, the external hemorrhoids disappear, and accompanied by other limb shortening deformities. The cause of the disease is in the early stage of the embryo, and the limb is based on the formation of a defect before 8 weeks, causing deformity.

The limbs become thinner and shorter: the most obvious manifestation of muscle atrophy, one is that the limbs are thinner, the circumference is shorter, and the other is that the muscles are slack without tension, commonly known as: "relaxation." Shortening of the limb is a clinical manifestation of muscle atrophy and progressive facial atrophy. Causes of the disease: Common causes of neurogenic muscle atrophy are disuse, nutritional disorders, ischemia and poisoning. Anterior horn lesions, nerve roots, nerve plexus, peripheral nerve lesions, etc. can cause conduction disturbances of nerve excitation impulses, thereby making some muscle fibers waste, resulting in disuse muscle atrophy.

Limb body flip: knee inversion, commonly known as "O-leg", "rocket legs", "bow legs", "squat basket legs". It means that at the knee joint, the tibia of the calf is rotated inward by an angle, so it is called "knee varus". The definition of knee varus is easily confused by the fact that the shape of the lesion is taken for granted: the definition of knee varus is not named after the angling angle, but is named after the direction of the calf tibia. Knee varus, the knee joint angle is pointing to the outside, so it is often mistaken for knee valgus.

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