congenital arteriovenous fistula
Introduction
Introduction to congenital arteriovenous fistula There is an abnormal channel between the arteriovenous fistula and the arteriovenous vein. This abnormal channel is called the fistula of the arteries and veins. Congenital arteriovenous fistula is caused by the abnormal passage of arteriovenous residual during the development and evolution of embryonic mesoderm. Lesions can occur in any part of the body, usually more common in the limbs, often involving many small arteriovenous branches, the fistula has multiple, the lesions are often diffuse, the mouth is fine, generally no vascular beats and murmurs, angiography is often difficult to observe To the mouth of the mouth, there are certain difficulties in diagnosis and treatment. basic knowledge The proportion of illness: 0.03% Susceptible people: no specific population Mode of infection: non-infectious Complications: pulmonary embolism
Cause
Congenital arteriovenous fistula
(1) Causes of the disease
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 island gradually stretches and connects to form the original capillary plexus. The arteries and veins originate from the same capillary plexus at the same time. The embryonic development process of the blood vessels can be roughly divided into plexus stage, reticular stage and tube trunk formation stage. In the reticular stage, if the enlarged vascular traffic is concentrated and tends to merge together, arteriovenous fistula can be produced. In the histology, numerous parallel blood vessel fusions can be seen, and multiple traffic is transmitted to each other. Small is called micro arteriovenous fistula. During the formation of the trunk, the abnormally extensive traffic between the general circulatory arteries and veins is called the great arteriovenous fistula. There are still many disputes about what causes the vascular dysplasia to form vascular malformations. Some scholars believe that congenital arteriovenous fistula is a hereditary chromosomal abnormality, but Desaive and Bessone 840 congenital malformations, only 7 cases suggest 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, and embryos of the circulatory system. Development is generally divided into three stages:
1 Undifferentiated vascular primitive phase: Undifferentiated stromal cells form bundles with the development of vascular cells. These early capillary cells spontaneously form tubular structures that are biologically similar to capillary-derived cells.
2 Reticulum: The original arterial and venous ducts begin to differentiate, but the main arteries and veins have not yet appeared.
3 vasculature based on the formation stage: mature blood vessel formation, developmental arrest or abnormality in any stage or development of circulatory system embryo development can lead to vascular aberration, in which the developmental arrest of the reticular stage is more likely to cause CAVF, dilated blood vessels Communicating, aggregating and tending to merge, histologically, vascular communication is often extremely small, called micro arteriovenous fistula; dysplasia during the formation of vascular basal trunks causes the abnormal vascular lumen to persist, forming a large arteriovenous fistula.
(two) pathogenesis
Classification
(1) Malan and Pugliioni classification: Malan and Pugliioni divide CAVF into two types: 1 main arteriovenous fistula: local or diffuse, low activity or high activity; 2 arteriovenous hemangioma: single or diffuse , low activity or high activity, based on morphological variation, further separate a single trunk, plexiform, aneurysm-like or localized subtypes.
(2) Szilagyi classification: Szilagyi et al. proposed another simple classification of CAVF based on the embryological development of the peripheral circulatory system: 1 vascular aneurysm caused by dysplasia of undifferentiated vascular network; 2 stagnation of reticular development leads to congenital Arteriovenous fistula, according to the size of abnormal traffic vessels and the location indicated by angiography, is divided into tiny fistula and large fistula arteriovenous fistula; 3 abnormal development of the vascular trunk formation period, leading to abnormal blood vessel lumen.
(3) Vollmar classification: In 1976, Vollmar divided CAVF into three types according to morphology from the perspective of surgery. Type I: there is a horizontal axis traffic branch between the surrounding arteriovenous trunks; Type II: peripheral arteriovenous trunk, horizontal axis There are many small traffic branches in the direction, and it involves local soft tissue and bone. This type is most common; type III: localized short-axis arteriovenous short-circuit, more common in the brain, rare in limbs.
2. Parts
CAVF can occur in any part of the body and affects all tissues in the affected area. It is most common in the limbs. The lower limbs are more common than the upper limbs. It can also affect the central nervous system, including the brain and spinal cord, and has abnormal clinical manifestations. The pelvic congenital Although arteriovenous fistula is rare, it can cause organ compression or vaginal bleeding due to its wide range of lesions. CAVF occurs in the lungs, kidneys and digestive tract.
3. Pathophysiology
CAVF is a benign lesion, but it has the biological behavior of malignant tumors. The lesions continue to develop and spread, often involving adjacent tissues and organs. Holman changes the circulatory system produced by congenital arteriovenous fistula and explains it by hemodynamics. Blood, like a flowing fluid, has the potential and natural instinct to flow to low and low pressure. Congenital arteriovenous fistula is a high-pressure, high-resistance arterial system with low-pressure, low-resistance, high-volume venous system. Abnormal communication, due to the low resistance of the venous end, makes the blood easily pass through the fistula without entering the capillary bed, resulting in hemodynamic changes. According to the location of the arteriovenous traffic, the size and number of the tube diameter, different local and systemic The effect is that the proximal end of the fistula (outflow tract) arteries are obviously thickened and distorted due to increased blood flow, and the circulation of arterial and venous collaterals is increased. The increase of circulating blood volume leads to the progressive expansion of the proximal vasculature of the fistula, and the distal arterial system is not obvious. Increased blood volume, according to the size of the branch and the corresponding resistance, when the ratio of the resistance of the distal vascular bed to the resistance of the collateral artery exceeds its proximal movement When the ratio of resistance is reversed, the distal arterial blood reverses, and the large chronic arteriovenous fistula, when the sputum resistance is low and the collateral circulation of the iliac crest is good, the distal artery can be used as the outflow tract of the sacral branch, and the venous system near the fistula is easy to produce. High pressure causes enlargement and variability of the entire venous bed. Although closure of the fistula can reverse the expansion of the heart and venous dilatation, long-term lesions can progress to the proximal arterial dilatation of the fistula and aneurysm formation. The amount of blood to be shunt depends on The diameter, type and distance from the heart, the larger the mouth, the closer to the heart, the more blood is shunted.
Venous arterialization in the lesion area, smooth muscle cell wall of the vascular wall, but no elastic layer appeared. The local action of arteriovenous fistula is directly related to the size of the iliac crest. The blood flow through the iliac artery is stealing blood, which can lead to perfusion pressure of surrounding tissue. Decreased, produces ischemia, and elevated venous pressure at the distal end of the fistula produces a series of clinical manifestations of venous hypertension, including distal venous stasis, venous insufficiency, occasional reverse blood flow, arteriovenous fistula Systemic manifestations include increased cardiac output, increased heart rate, enlarged heart, cardiac hypertrophy, decreased diastolic blood pressure with increased pulse pressure and increased blood volume. In a few cases, if the blood flow through the iliac crest is large, the heart is discharged. The increase of the amount can increase the heart rate, reduce the myocardial contractility, and finally produce high blood volume heart failure. Because of the large amount of CAVF, the effect on the systemic circulatory system is not as obvious as that of acquired arteriovenous fistula.
Prevention
Congenital arteriovenous fistula prevention
The disease is a congenital disease, so there is no effective preventive measure. The diagnosis needs to be differentiated from the lesions of various parts, and the prevention of complications should be prevented. In particular, it is necessary to prevent the embolic material from causing other embolic diseases caused by the transfer of the fistula.
Complication
Congenital arteriovenous fistula complications Complications pulmonary embolism
The patient can usually have a high fever of more than 39 °C after 24 hours of embolization, which may be caused by muscle and tissue destruction; the embolism can enter the pulmonary artery through the fistula and cause pulmonary embolism; if the operation is not strict, the operation can be concurrent Septicemia; venous stasis can be secondary to thrombosis, can lead to pulmonary embolism, congenital arteriovenous fistula is a benign lesion, but has the biological behavior of malignant tumors, the lesions continue to develop, spread, often extensively invade adjacent tissues and organs, such as muscles , bones, nerves, etc., until it spreads throughout the body and torso.
A small number of patients with a long sputum and a long course of disease can be complicated by heart failure. Because of short circuit between the arteries, the peripheral vascular resistance is significantly reduced, and the cardiac stroke output is significantly increased. In addition, the adrenaline, angiotensin, and aldosterone systems are still passed. Excitement causes sodium, water retention and tissue protein utilization, increased blood volume, and increased heart burden, leading to heart failure.
Symptom
Congenital arteriovenous fistula symptoms Common symptoms Dyspnea, lower back pain, heart enlargement, fatigue, muscle atrophy, varicose skin temperature, reduction, cyanosis, oppression, mouthwash test
Most congenital arteriovenous fistulas exist at birth, generally concealed, without any clinical symptoms, and do not attract the attention of parents. The effects of puberty development and endocrine, trauma, excessive activity and other factors often stimulate the activation of arteriovenous fistula.
(1) Limb growth, over-grown development: adolescents have not closed the skeletal end, arteriovenous fistula is already present, so the affected limb is generally longer than the healthy side, and the limb circumference is increased. This hypertrophy includes bone and soft tissue factors, bone elongation and cortical growth. Thick, the length of the limb is 2 to 5 cm longer than the healthy side. The patient often feels heavy limbs, swelling and pain, and sometimes has lower back pain. This is caused by the sloping limbs and the curvature of the spine due to the length of the limbs.
(B) skin fetal caries, temperature and structural changes: congenital arteriovenous fistula and congenital hemangioma and exist in the same site, vascular disease is capillary hemangioma, blue-red, some flat, and some high protrusion in the skin The size varies from a few centimeters to a few centimeters in diameter. It also surrounds the entire limb. When the venous insufficiency occurs, the skin is painstakingly purpura, the arterial insufficiency is pale, the skin color can be changed by the receptor position, and the skin temperature is increased in the ankle. Gilmon and Bolam It has been reported that there is one case, the skin temperature of the disease side is up to 1.5 °C than the same part of the healthy side, the proximal end of the tendon tends to be normal, but the distal skin temperature is lowered, and the skin temperature is often increased with local sweating, and the arteriovenous fistula is pulsating. The performance of the mass, the skin structure is corroded, the atrophy changes, the skin is thin and transparent, the chronic venous stasis, the skin has hardening and thickening, and loses elasticity.
(C) varicose veins, ulcers and gangrene: the presence of arteriovenous fistula, often first manifested as local vein significant varicose, when the pupil is larger, varicose veins have pulsation, can be complicated by skin ulcers, dermatitis and bleeding, a small number of patients due to distal Limb blood circulation disorders, ulcers and gangrene can occur at the distal end of the foot and in the hand.
According to the size and location of the mouth, it can be divided into three types:
1 dry arteriovenous fistula, there is traffic branch between the peripheral arteriovenous trunk in the horizontal axis direction, most of the fistula is slightly larger, so there are many shunts between the arteries and veins, there may be murmurs, tremors, varicose veins and Sickle aneurysm.
2 tumor-like arteriovenous fistula: between the surrounding arteriovenous trunk, there are many small traffic branches in the direction of the horizontal axis, and involve local soft tissue and bone, local tissue with tumor-like phlegm advocate, generally less blood flow, local No noise and tremors.
3 mixed type: there are dry and tumor-like multiple movements, intravenous traffic.
1. Symptoms: About 2/3 of CAVF patients are more complicated. Although most of the lesions are already present at birth, symptoms usually appear during puberty. Pregnancy and trauma can aggravate the condition. Clinical manifestations vary with the location of the fistula. Changes, subcutaneous congenital arteriovenous fistula or involving the head, neck lesions can lead to deformity, affecting the appearance, varicose veins, fever, pain, swelling, deformity or abnormal growth of the limbs of the arteries and veins, such as unilateral limbs Superficial varices or varicose veins occur in rare areas to be alert to the possibility of CAVF. If the patient has large hemorrhage and obvious hemodynamic changes, it may be accompanied by systemic symptoms, including difficulty breathing or fatigue after exertion. Internal organs CAVF may exhibit local or systemic symptoms, such as gastrointestinal arteriovenous fistula may have unexplained gastrointestinal bleeding, renal lesions may be characterized by hematuria or hypertension.
2. Signs: Signs vary with the extent and extent of the lesion.
(1) Superficial congenital arteriovenous fistula:
1 Skin manifestations: Most patients have skin changes, and about 50% of the lesions that are confined to the limbs have fetal and hemangioma-like manifestations.
2 abnormal skin temperature: the affected limb often has elevated skin temperature, but the distal skin temperature of the limb can be lower than normal.
3 may have limb swelling and hair hyperplasia.
4 venous hypertension: signs of chronic venous insufficiency, such as edema, skin thickening, pigmentation, ulcers and bleeding, etc., ulcers often occur in the distal part of the limb, and primary deep venous insufficiency occurs in the boots In the area, the varicose veins of CAVF are not distributed with the normal superficial veins. When the fistula is large, the superficial varicose veins may have pulsation.
5 Circulatory system abnormalities: the mouth of the mouth can often touch the tremor, auscultation and characteristic murmurs, showing "machine-like" with increased systolic period, small arteriovenous fistula can sometimes be inconspicuous, a small number of patients with large fistula, long course of disease can be concomitant Failure, but most patients have normal or only mildly enlarged heart.
6Branham-Nicoladoni sign (compression mouth test): After the fistula is compressed, the blood flow diverted through the branch is forced into the arterial system, and the increase in peripheral circulation resistance and the sudden increase in extra blood volume in the arterial system raises blood pressure and stimulates The aortic decompression nerve and the nerve endings in the carotid sinus inhibit the vasomotor center and slow the heart rate. This sign is often absent in patients with no obvious systemic symptoms of CAVF.
7 Abnormal limb development: the affected limbs can be thickened, the bones and soft tissues are often hypertrophic, and sometimes the affected limbs may have hair hyperplasia and hyperhidrosis. The vascular surgery of the Ninth People's Hospital affiliated to Shanghai Second Medical University reported 45 cases of congenital arteriovenous fistula of the limbs. There are varying degrees of varicose veins, hair hyperplasia, skin flushing, sweating, elevated skin temperature, pain, heavy feeling and other abnormalities, limb thickening, increased in 45 cases (100%), 42 cases have vascular murmur (93 %), 34 cases of tremor and tremor and pulsation (86%), 28 cases of skin pigmentation (62%), 12 cases of ulcers, gangrene (26%), 6 cases of muscle atrophy (13%), 5 There was a history of bleeding (11%) and 3 cases of pulsatile mass (6%).
(2) Internal organs CAVF: Congenital arteriovenous fistula of the lungs obtain blood supply from the pulmonary circulation or systemic arteries, and congenital arteriovenous fistulas originating from the pulmonary circulatory system, only 10% have symptoms, and patients often can be 30 or 40 years old. The diagnosis is that women are twice as likely as men, about 60% of the skin, mucosal capillary hemangioma (Rendu-Osler-Weber syndrome), about 60% of these cases are located below the pleural visceral and lower lobe, heart blood is Right to left shunt, but typical lesions do not cause systemic hemodynamic changes, clinical manifestations of fatigue, fatigue, fatigue, etc., 20% of cases have brain abscess, cerebrovascular accident, hemoptysis, hemothorax and other complications Symptoms, physical examination often found cyanosis and clubbing, combined with continuous vascular murmur in the lungs, enhanced inspiratory, chest radiographs often have a single, limited non-calcified lesions (75%), located in the lower lung lobe 1 / 3, without the expansion of the heart, pulmonary arteriovenous fistula obtained from the systemic circulation of blood, mainly from the radial artery, internal mammary artery, intercostal artery or directly from the aorta, often cause the heart blood to shunt from left to right, Often obvious Hemodynamics, leading to enlargement of the heart and left ventricular hypertrophy.
(3) Other internal organs CAVF: 50% of patients with renal disease have hematuria and hypertension, abdominal vascular murmurs are often found in physical examination; arteriovenous fistula of mesenteric or celiac circulation may have hypertension, ascites or gastrointestinal bleeding; intrahepatic arteriovenous It is rare, but it can have large liver, jaundice and fulminant heart failure.
According to medical history and physical examination, diagnosis is generally not difficult. Because congenital arteriovenous fistula is accompanied by varicose veins, when varicose veins are found in children or adolescents without obvious causes, especially unilateral or uncommon parts, first Consider the possibility of congenital arteriovenous fistula, such as limb growth, thickening, local tissue swelling, cavernous hemangioma, pulsation and tremor, audible vascular murmur, etc., is more helpful for diagnosis.
Examine
Congenital arteriovenous fistula examination
1, arterial pulsation instrument examination
Arterial pulse volume segmental tracing can increase the proximal tremor of the fistula, and the distal arterial pulsation is reduced. The digital plethysmograph (pulse capacity tracing) shows an increase in the pulse volume at the fistula, and its volume is proportional to the size of the fistula. , Doppler ultrasound scanner, double-function color Doppler can show microscopic fistulas that can not be found by angiography, abnormal blood flow distribution of large blood vessels, venous insufficiency or thrombosis.
2, peripheral vein pressure measurement and blood oxygenation
MeCarn et al reported that the application of venous blood oxygen content can be used to locate peripheral arteriovenous fistula, and the blood oxygen content of the distal end can be compared to determine the site of arteriovenous fistula. By directly measuring partial venous oxygen partial pressure and hemoglobin saturation. It can be confirmed that the varicose veins produced by the arteriovenous fistula shunt can show an increase in venous pressure.
3, ultrasound examination
(1) Two-dimensional sound image: Because the tumor-like arteriovenous fistula is relatively high, the fistula is small, and it is not easy to directly observe the fistula, dry and mixed arteriovenous fistula from multiple examinations of congenital arteriovenous fistula, which can be the same as the double limbs. Level, measuring the inner diameter of the arteriovenous and the obvious change of the inner diameter of the artery, looking for the fistula (the inner diameter of the proximal end of the fistula is widened, the inner diameter of the distal end is thinner), and the inner diameter of the proximal end of the fistula is also widened.
(2) Color Doppler flow imaging: the two-dimensional ultrasound is easy to display the fistula, the blood flow at the fistula is multicolored mosaic color; the color flow in the arterial lumen near the heart of the fistula is bright, and the distal end of the fistula The color of the blood flow is dim; the blood flow in the vein near the heart is also accelerated, and the flow path is widened.
(3) Doppler flow rate curve: measurement at the mouth and sputum flow rate curve, high speed and low resistance, continuous blood flow during diastole; bilateral control of the proximal extremity artery of the affected limb, high blood flow and low resistance, continuous diastolic phase Blood flow, the distal end of the flow velocity is slowed or normal; the blood flow of the proximal ventricle is arterialized, and the blood flow velocity is accelerated.
(4) Contrast echocardiography: After intra-arterial injection of indocyanine green, it can show the traffic between arteries and veins, ultrasonic detection of systemic venous system, arteriovenous fistula of suspicious internal organs, or residual arteriovenous fistula after surgical resection. Evaluation is especially applicable.
3.99mTc radionuclide scanning: 99mTc labeled human serum protein nuclides scan, can detect the blood flow of arteriovenous fistula shunt, the labeled 35m particles first enter the main nourishing artery after injection, then enter the vein, detect it with -camera Radioactivity in the lungs can be used to monitor disease progression.
4. Arteriography
In 1933, Hortonh and Ghormley first injected 10 ml of cerium oxide into the radial artery of a male patient to show the hand CAVF. Seldinger intubation technique was used to selectively or superselectively intubate the femoral artery or radial artery to define the lesion. Contrast can detect the size of arteries and arteriovenous fistulas, and rapid radiography of super-selective intubation of multiple nourishing arteries can increase the detection rate of sacral branches. The typical manifestations of angiography are multiple abnormal trunk and arteriovenous communication. With the advance of the venous phase, about 40% of patients have clinical manifestations of CAVF, but angiography can not confirm arteriovenous communication, so the indirect basis of angiography is also helpful for diagnosis, such as increased blood flow into the arteries, distortion of the proximal arteries Dilation, early venous filling, contrast agent retention at the fistula site and lack of distal arterial tree contrast agents.
5. CT examination
CT scan is simple and easy to apply to the lesions of the head, neck, trunk and limbs. It can show the relationship between the lesion and the surrounding tissue, and enhance CT to show soft tissue and bone hypertrophy.
6.MRI and MRA
MRI and MRA can identify different tissues and detect fluid status. At the same time, MRA contains no contrast agent, no radioactivity, and can detect the coronal and sagittal planes of the lesion and abnormal blood vessel communication.
CT, MRI and angiography are very important for the diagnosis of CAVF. Before treatment, angiography should be performed. According to the extent and extent of the lesion, the location of the sacral branch should be used to determine whether there is any indication for surgery. Postoperative examination can be used to see if the operation is complete or not. relapse.
Diagnosis
Diagnosis and diagnosis of congenital arteriovenous fistula
The differential diagnosis of this disease is troublesome, because the arteriovenous fistulas occurring in different parts need to be identified with some unique diseases in this part, which cannot be listed here. Now focus on some diseases of the lower extremity veins (simple large The distinction between saphenous varicose veins and deep vein thrombosis syndrome is related to the identification of congenital arteriovenous fistula. Because congenital vascular disease has many similarities with congenital arteriovenous fistula in clinical manifestations, it is easy to be confused.
1, etiology identification
According to hemodynamic changes, the lower extremity venous diseases can be divided into two types: (1) blood reflux lesions: all caused by the disease of the valve itself, mainly including primary deep venous insufficiency, simple saphenous vein Varicose veins, complete recanalization after deep venous thrombosis (pipe recanalization, but the valve has been destroyed), congenital deep vein without valve disease, etc., accounting for about 70% of lower extremity venous disease, (2) reflux obstructive lesions: mainly Complete occlusion and partial recanalization after deep venous thrombosis; a few are congenital venous malformation, bone hypertrophy syndrome, lack of deep veins of the lower leg, left common iliac vein compression syndrome, etc., accounting for about 30% of lower extremity venous disease, lower limbs Most of the varicose veins occur in the saphenous vein. The most important reason is the weakness of the vein wall or the valve, which makes the vein wall easy to expand. The proximal venous valve is incompletely locked, causing blood to flow backwards, and the blood backflow gradually destroys the distal valve. Finally, varicose veins are produced. The varicose veins of the lower extremities are more common in workers who are standing for a long time. Sometimes they can be seen in pregnant women or patients with pelvic tumors, which cause increased intra-abdominal pressure. Congenital arteriovenous fistula is due to embryos. Due to abnormal development, the etiology is now basically clear. In the early embryonic yolk sac wall and the extramedullary mesoderm of the pedicle, some cells aggregate into cells of different sizes, called blood islands, and the blood islands gradually extend and connect with each other. The formation of primitive capillary plexus gradually evolves into capillary-like blood vessels as the embryo matures, and eventually forms recognizable arteries and veins.
2, pathological identification
The pathological changes of varicose veins mainly occur in the middle layer of the vein wall. Due to blood stagnation, the venous pressure increases, and the early muscle fibers and elastic fibers are compensatory thickening. In the later stage, the muscle fibers and elastic fibers shrink and disappear, and all of them are replaced by connective tissue. It is thinned by expansion, and some places become thick due to the proliferation of connective tissue, forming uneven nodules. At the same time, the valve is atrophied and hardened, and the function is lost. After varicose veins, the blood flow of the lower extremities slows down and reverses, causing congestion in the lower extremities. , blood oxygen content decreased, capillary wall permeability increased, fluid, protein, red blood cells and metabolite exudation, causing fibrosis and pigmentation, local tissue due to hypoxia, malnutrition, reduced resistance, easy to concurrent Dermatitis, lymphangitis and ulcers, after deep vein thrombosis of the lower extremities, in the process of thrombus from mechanization to complete recanalization, there are the following characteristics:
(1) The thrombus causes reflux obstruction, and after recanalization, the blood is reversed due to valve damage, and the venous system of the affected limb is also in a state of congestion and high pressure.
(2) Backflow barriers and backflows often exist at the same time, but there are primary and secondary points.
(3) After deep vein congestion, the saphenous vein will be compensatoryly dilated, which is generally not serious. After the destruction of the cryptic-femoral venous valve, there is significant variability.
(4) dystrophic lesions occur in the highest pressure foot boots area, which is the result of valve damage after traffic vein recanalization. The passage between the congenital arteriovenous fistula and the vein is small and large. Rinse mouth is rare, it is generally difficult to determine the location of the fistula, congenital arteriovenous fistula is a benign lesion, but has the biological behavior of malignant tumors, the disease part is constantly developing, spreading, often extensively invading neighboring tissues and organs, such as muscles, bones, Nerve, etc., until it spreads throughout the body and trunk, and can cause systemic blood circulation disorders such as heart failure.
3, clinical manifestations
In the venous diseases of the lower extremities, regardless of blood reflux lesions or reflux disorders, the main clinical manifestations include: superficial varices, swelling, pain and dystrophic lesions in the lower leg, including dermatitis, eczema, pigmentation and ulceration. Wait.
Congenital vascular malformation can be similar to venous disease, but it also has obvious characteristics. Through detailed medical history and physical examination, it will obtain strong evidence for diagnosis. Congenital arteriovenous fistula is most common in lower limbs, especially The crotch, infants and young children are often in a period of insidious or low activity, no obvious symptoms, increased endocrine to school age and adolescence, increased activity and trauma, and promote the rapid increase of arteriovenous fistula, gradually showing clinical symptom:
(1) Increased limb enlargement: During adolescence, there are extensive movements around the bones, venous anastomosis, increased blood flow, abundant intramedullary circulation, high blood oxygen content, and long limbs.
(2) Increased skin temperature: Due to the abundant blood supply and venous congestion, the temperature of the lesion is significantly increased, and the temperature difference can reach up to 6 °C.
(3) Hemangioma (fetal): Congenital arteriovenous fistula often coexists with congenital hemangioma at the same site.
(4) vascular murmurs and tremors.
(5) superficial varices, venous insufficiency: intra-arterial hypertension, flow through the fistula to increase venous pressure, lumen enlargement, venous valve damage or loss of function, venous blood reflux, formation of superficial varices, blood stasis , as well as skin pigmentation, eczema, infections and ulcers.
(6) Insufficient blood supply to the arteries.
4, auxiliary inspection
For patients with superficial varicose veins, it is best to use an effective examination method to find out the cause and understand the complete condition before you can choose the appropriate treatment according to the relevant information obtained. In this respect, the traditional Trendeden-burg Test and Perthes test, obviously can not meet the requirements, Trendeden-burg test positive, only suggest the cryptic-femoral valve and traffic vein dysfunction, can not explain the cause of superficial varices; Perthes test positive can be diagnosed as deep venous return obstruction But can not prompt the cause of the cause, but can not understand the location, extent and extent of the lesion; Perthes test negative, although suggesting deep vein patency, but can not explain whether there is deep vein reflux lesions, scholars believe that venography is still the diagnosis of lower limbs The most reliable method of examination for venous diseases, and to further identify congenital arteriovenous fistula, some other tests can be performed.
(1) Deep vein antegrade angiography of lower extremities: can understand the function of deep venous valve and traffic branch.
(2) deep vein retrograde angiography of the lower extremity: can show the reflux of deep venous valve insufficiency.
(3) Percutaneous venous cannulation: the function of each pair of valves in the femoral vein can be located.
(4) Measurement of peripheral venous pressure and PaO2 measurement: it can reflect reflux congestion, indirectly understand the function of the valve, and because of the simple operation, it is often used as a screening test. When there is arteriovenous fistula, the venous pressure around the fistula is elevated. The venous blood PaO2 content increased.
(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) Arterial angiography: rapid continuous filming, showing whether there is abnormal arteriovenous traffic, as well as the location of the fistula and the extent of the lesion. When the arteriovenous fistula occurs, the proximal artery may be distorted and expanded, the corresponding early vein development, and the blood vessel. The tumor is dilated, and the branches of the veins and veins are agglomerated.
