The wound forms a pulsating mass

Introduction In patients with acquired arteriovenous fistula, the arterial and venous traffic can be divided into direct and indirect. When the adjacent vein is injured at the same time, the wound edges directly meet each other and can be directly transported within a few days. Arteriovenous fistulas, such as the wounds of arterial veins, cannot be directly conjugated, but there is a hematoma between the two, and the hematoma is later formed, forming a capsule or tube that runs between the artery and the vein, called indirect sputum. The proximal arteries of the tendon are progressively dilated and elongated; the arterial wall is initially thickened, degenerative changes occur later, smooth muscle fibers are atrophied, elastic fibers are reduced, the wall is thinned, and atheromatous plaques are formed, such as large pupils, adjacent The main artery of the fistula can be inflated to form an aneurysm, and the distal artery is reduced due to a decrease in blood flow. The vein gradually expands, the distal end can reach the last valve, and the proximal end can reach the vena cava. If the pupil is large, the pressure in the vein is suddenly increased. After a few weeks of trauma, a pulsatile mass can be formed due to venous expansion.

Cause

Trauma is the main cause of acquired arteriovenous fistula, especially penetrating injuries, such as knife stab wounds, gunshot wounds, steel and glass fragments. When injured, the adjacent arteries and veins in the same sheath were damaged, and an abnormal channel of arteries and veins was established to form arteriovenous fistula. Percutaneous angiography and trauma during surgery are also common causes. Generally, the external penetrating wound is small, and adjacent muscles and soft tissues prevent blood from escaping, forming a hematoma in the local soft tissue, and forming a wall of the arteriovenous vein after the hematoma is machined. Trauma arteriovenous fistula caused by firearms such as shotguns, grenades, etc. There may be multiple fistulas between the arteries and veins. Squeeze injuries can also cause arteriovenous fistulas. Such as spleen, kidney resection, spleen pedicle, kidney pedicle ligation can occur arteriovenous fistula. Shoulder and hip contusion can cause local arteriovenous fistula.

Other causes of arteriovenous fistula are rare. Spontaneous aneurysm hardening gradually adheres, corrodes and finally penetrates the accompanying vein; bacterial arteritis, bacteria that stay at the bifurcation of the artery cause arterial perforation and pass into the accompanying vein, and arteriovenous fistula may occur.

1, through injury: the vast majority of acquired arteriovenous fistula is caused by penetrating injury. Such as a variety of puncture wounds, especially high-speed bullets, sodium iron and glass fragments flying damage. At the time of the injury, the arteries and veins within the same sheath were damaged together. A closed fracture pierces a nearby blood vessel due to a sharp fractured end or broken bone. Percutaneous angiography and trauma during surgery are the most common causes. Fourth, the five lumbar intervertebral discs are close to the iliac vessels. When performing discectomy, it is easy to cause iliac vein injury caused by iliac vein injury. Generally, the external penetrating wound is small, because a large amount of bleeding is prevented by the adjacent muscles and soft tissues, and a hematoma is formed in the local soft tissue, and the wall of the arteriovenous fistula is formed after the hematoma is machined.

2, crush injury: parallel arteries and veins can be squeezed at the same time can occur arteriovenous fistula. Iatrogenic injuries such as splenectomy and nephrectomy, massive ligation of the spleen and renal pedicle; femoral artery ligation during amputation; thyroidectomy, upper extremity arteriovenous ligation, can occur arteriovenous fistula. External violence acts on soft tissues, and soft tissue is squeezed on the bones. For example, shoulder and hip contusions can cause local arteriovenous fistula, and skull fracture can cause arteriovenous fistula of meningeal blood vessels.

3, other reasons: aneurysms gradually produce adhesions, corrosion, and finally wear through the accompanying veins, and even tumor ulcers can break into the large blood vessel wall can occur arteriovenous fistula.

an examination

Related inspection

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The diagnosis of arteriovenous fistula is generally not difficult. In the history of penetrating trauma, the patient can find a pulsatile mass on his own, and there is a local snoring. One limb is swollen, varicose veins and venous valve insufficiency, local skin temperature is higher than the contralateral side, scars, murmurs and tremors in the injured area should be considered, the diagnosis of arteriovenous fistula should be considered. Patients with acute arteriovenous fistula often have severe multiple trauma or penetrating injuries in the limbs. When the patient is examined, the diagnosis and treatment of arteriovenous fistula is often delayed due to the focus on the severe injury of bones and soft tissues.

Differential diagnosis

The wound forms a differential diagnosis of a pulsatile mass:

1, acute arteriovenous: sputum can appear immediately after the injury, or after the arteriovenous communication is filled with blood clots dissolved, there is a hematoma in the local injury, the vast majority have tremors and murmurs. In most patients, the limbs at the distal end of the arteriovenous fistula can still twitch and pulsate the arteries, but weaker than the healthy side. When the lower extremity superficial femoral artery is accompanied by deep femoral artery injury, the dorsal artery of the foot and the dorsal artery cannot be beaten, and there is limb ischemia.

2, chronic arteriovenous fistula: the patient's affected limb swelling, numbness, pain, fatigue. There is a snoring in the pulsatile mass. Heart failure can have chest tightness, palpitations, and shortness of breath.

Common signs are:

There is noise and tremor in the 1 area. Regardless of the size of the arteriovenous fistula, a typical, rough and continuous rumble can be heard in the arteriovenous fistula, which is called machine-like noise. The murmur is enhanced during systole and is transmitted proximally and distally along the main vessel. This murmur and pseudoaneurysm causes weak diastolic murmurs and systolic murmurs caused by arterial stenosis.

2 Pulse rate is accelerated: this is the result of a Braibridge reflex caused by an increase in venous return or an increase in cardiac workload due to a decrease in mean arterial pressure (Marey's law).

3 heart enlargement and heart failure: As a large amount of blood flows into the vein rapidly through the pupil, the venous pressure increases, and the amount of blood returning from the heart increases, causing the heart to expand. Progressive enlargement of the heart can lead to heart failure. The extent of heart enlargement and heart failure is closely related to the size, location, and length of time of the fistula. The closer the heart is, such as the direct branching of the aortic arch (carotid artery, no arteries, subclavian artery) and the venous fistula formed by the accompanying vein, early and severe heart failure. Pate reports arteriovenous fistula in the direct branching of the aorta. Heart failure can occur as early as 6 weeks after trauma. Most of the arteries and veins of the limbs occur, and 9 patients with arteriovenous fistula after cardiac resection have local pain. , ascites and abdominal pain symptoms.

4 local warming increased: the skin temperature of the affected limb in the arteriovenous fistula area increased, the high arteriovenous fistula is far away, the skin temperature may be normal or lower than normal.

5 venous insufficiency: direct communication between arteries and veins, so that the veins increase. In most patients, superficial veins near or distal to the arteriovenous fistula are dilated and curved. Skin pigmentation is associated with calf cellulitis, ulceration of the toes or fingers, and symptoms similar to those of deep phlebitis.

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